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RELATED APPLICATION
[0001] This is a continuation-in-part of copending patent application Ser. No. 09/885,635 filed Jun. 21, 2001 which is a continuation-in-part of patent application Ser. No. 09/635,320 filed Aug. 9, 2000.
FIELD OF THE INVENTION
[0002] The invention provides an improved striker attachment for wood comminuting rotors which facilitates a keyed attachment enabling both a single fastener to be utilized attaching the striker to the striker retainer, and rapid removal and replacement of the striker.
BACKGROUND OF THE INVENTION
[0003] Prior art comminuting apparatus for reducing large diameter wood products and stumps to a desired size, have comprised a reduction chamber, with an impact rotor positioned concentrically therein, in combination with a housing, drive motor and infeed chute. The impact rotor is formed with a plurality of horizontally elongate impact strikers at its periphery. The rotor is positioned so that the elongate wood product or stump falling under the influence of gravity through the infeed chute is directed against the strikers, and repelled ahead of the rotor's rotational direction against an anvil formed along one side of the reduction chamber.
[0004] Prior art wood comminuting apparatus are often capable of comminuting trees or parts thereof up to 40 inches in diameter (see e.g. U.S. Pat. No. 5,165,611). Strikers used for the comminution are bolted directly to mounting projections on the rotor which is rotated to produce the comminution. Maintenance to change strikers has required complete removal of the striker mounting bolts with the consequent potential loss of bolts and uneconomical use of maintenance time, especially in view of the substantial number of strikers on a rotor of such apparatus. Strikers of the prior art are typically fastened with two (2) hex head or similar studs, stud-bolts or bolts, relying on fastener torque to position and retain the strikers, resulting in the above noted potential loss of bolts and uneconomical use of maintenance time.
SUMMARY OF THE INVENTION
[0005] It is an object of the invention to improve maintenance time and ease of striker replacement in comminution apparatus minimizing the potential for loss of components including fasteners.
[0006] It is a further object of the invention to improve the support and alignment of the strikers for initial installation of the strikers, during operation of the comminuting device, and during maintenance or replacement of strikers.
[0007] According to the invention there is provided a comminuting striker assembly for mounting on a rotor of a comminuting apparatus, the comminuting striker assembly comprising:
[0008] a striker having first and second opposed faces with the first face defining at least one cutting edge, and the second face of the striker having a cooperating surface; and
[0009] a striker retainer having a retainer base for attachment to a rotor and a leading face for attachment to the striker, the leading face having a striker support surface for engaging with the cooperating surface of the striker to provide primary support for the striker; wherein
[0010] the second face of the striker defines an alignment component while the leading face of the striker retainer defines a complimentary alignment component arrange to mate with the alignment component of the striker and to facilitate desired alignment of the striker with the striker retainer.
[0011] Also according to the invention there is provided a comminuting striker assembly for mounting on a rotor of a comminuting apparatus, the comminuting striker assembly comprising:
[0012] a striker having first and second opposed faces with the first face defining at least one cutting edge, and the second face of the striker having a cooperating surface; and
[0013] a striker retainer having a retainer base for attachment to a rotor and a leading face for attachment to the striker, the leading face having a striker support surface for engaging with the cooperating surface of the striker to provide primary support for the striker; wherein
[0014] one of the second face of the striker and the leading face of the striker retainer defines a first slot and the other of the second face and the leading face defines a complimentary first key arrange to engage the first slot thereby to facilitate proper alignment of the striker with the striker retainer, with the first slot and first key extending perpendicular to the cooperating surface and the striker support surface.
[0015] When the first key and the first slot are engaged, a single bore extends through the striker retainer from the leading face to a following face of the striker retainer; and a threaded fastener extends through the single bore in the striker retainer to the striker from the following face to attach the striker to the striker retainer by the use of a corresponding threaded bore in the striker. Preferably the corresponding threaded bore of the striker is a blind bore which opens to the second face of the striker but does not extend through the striker to the first face of the striker. In addition, according to the invention, one of the second face of the striker and the leading face of the striker retainer defines a second slot extending perpendicular to the first slot and the other of the second face and the leading face defines a complimentary second key arranged to engage the second slot thereby additionally to facilitate proper alignment of the striker with the striker retainer.
[0016] According to the invention there is also provided a method of mounting a comminuting striker assembly on a rotor of a comminuting apparatus, the method comprising the steps of:
[0017] providing a striker with first and second opposed faces with the first face defining at least one cutting edge, and forming a cooperating surface in the second face of the striker; and
[0018] providing a striker retainer with a retainer base for attachment of the comminuting striker assembly to a rotor and with a leading face for attachment of the striker to the striker retainer, forming the leading face with a striker support surface for engaging with the cooperating surface of the striker to provide primary support for the striker; and
[0019] the second face defining an alignment component;
[0020] leading face defining a complimentary alignment component arrange to mate with the alignment component of the striker to facilitate desired alignment of the striker with the striker retainer.
[0021] Also according to the invention there is provided a method of mounting a comminuting striker assembly on a rotor of a comminuting apparatus, the method comprising the steps of:
[0022] providing a striker with first and second opposed faces with the first face defining at least one cutting edge, and forming a cooperating surface in the second face of the striker; and
[0023] providing a striker retainer with a retainer base for attachment of the comminuting striker assembly to a rotor and with a leading face for attachment of the striker to the striker retainer, forming the leading face with a striker support surface for engaging with the cooperating surface of the striker to provide primary support for the striker; further comprising the steps of:
[0024] defining a first slot in one of the second face of the striker and the leading face of the striker retainer and defining a complimentary first key on the other of the leading face of the striker retainer and the second face of the striker arrange to engage the first slot to facilitate desired alignment of the striker with the striker retainer; the first slot and the first key extending perpendicular to the cooperating surface and the striker support surface.
[0025] In addition according to the invention, preferably a single bore is extended through the striker retainer from the leading face to a following face thereof;
[0026] a corresponding threaded bore is formed into the striker from the second face of the striker;
[0027] a threaded fastener is provided; and
[0028] the threaded fastener is passed through the single bore of the striker retainer from the following face of the striker retainer to the striker to attach the striker to the striker retainer by the use of a corresponding threaded bore in the striker. Also preferably the corresponding threaded bore in the striker is formed as a blind bore opening to the second face of the striker which does not extend through the striker to the first face of the striker.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] The invention will now be described, by way of example, with reference to the accompanying drawings, in which:
[0030] [0030]FIG. 1 is an orthogonal view of a rotor with a plurality of strikers and retainers mounted thereto, showing two types of strikers;
[0031] [0031]FIG. 2 is a sectional end view of a rotor of the present invention showing two types of strikers attached to the rotors by way of retainers and bases;
[0032] [0032]FIG. 3 is a perspective view of a preferred embodiment two edged striker with cruciform key slots, and a single fastener hex opening;
[0033] [0033]FIG. 4 is a side elevation of the striker of FIG. 2;
[0034] [0034]FIG. 5 is a rear view of the striker of FIG. 2 showing the cruciform key slots;
[0035] [0035]FIG. 6 is a perspective view of a striker retainer according to the present invention with male cruciform keys to engage the cruciform key slots;
[0036] [0036]FIG. 7 is a front elevation of the striker retainer of FIG. 6;
[0037] [0037]FIG. 8 is an alternative embodiment single tooth striker according to the invention;
[0038] [0038]FIG. 9 is an elevation of a further embodiment of striker and striker retainer of the present invention shown assembled and bolted together;
[0039] [0039]FIG. 10 is a perspective view of the striker retainer shown in FIG. 9; and
[0040] [0040]FIG. 11 is a perspective of the striker shown in FIG. 9.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0041] Referring to FIG. 1, a prior art assembly of rotor 2 of a wood comminutor defines striker carrying faces 4 for supporting a retainer bases 6 which supports strikers 8 by way of striker retainers 10 against comminuting forces during comminution with the face 4 and cutting edge 12 of the striker 8 facing in the direction of rotor rotation 14 about rotor axis 16 . Projections 18 on the rotor 2 , one for each striker 8 , direct a work piece (not shown) into the cutting edge 12 of each striker 8 and away from striking the work piece facing side of retainer base 6 . The configuration of strikers, striker retainers, and projections shown herein are based on prior art designs, and are therefore not discussed in detail herein.
[0042] Referring to FIG. 2, the cruciform slot and key attachment of a striker 20 to striker retainer 22 , of the present invention, is shown. The striker 20 is captively mounted to striker retainer 22 by a single bolt 28 extending through bore 26 to a nut 24 and fixed against rotation by a hex machined opening 30 in striker 20 . Striker retainer 22 is captively mounted by a weld joint 32 to retainer base 6 , which in turn is captively mounted to rotor 2 at retainer carrying face 4 by two bolts 34 extending through two countersunk bores 35 through retainer base 6 and mating threaded bores 36 in rotor 2 .
[0043] Also shown in FIG. 2 is a second design of striker 38 which has a blind threaded hole for accepting bolt 40 . The arc of striker rotation 42 is shown in FIG. 2.
[0044] Referring to FIGS. 3, 4 and 5 , preferred embodiment two edged striker 20 is shown. Cutting edges 12 , hex shaped machined recessed opening 30 , bolt clearance bore 44 , and slots 46 are shown. Two slots 46 are machined perpendicular to each other and each centrally aligned with a centerline of clearance bore 44 . The width X of slots 46 are machined to matingly receive the machined keys 50 of a striker retainer 22 (FIGS. 6 and 7), with a tight clearance fit. A tight clearance fit ensures minimal twisting motion is permitted between the striker and striker retainer. The machined depth D of slots 46 are equal to at least the height H of mating keys 50 shown in FIGS. 6 and 7 to ensure complete engagement of keys 50 within slots 46 .
[0045] Referring to FIGS. 6 and 7, a striker retainer 22 is shown, with the raised machined keys 50 , machined to mate in a tight clearance fit with the slots 46 of striker 20 . Striker retainers are shaped to have a relatively tall leading face to which the striker is attached, and a relatively short opposed following face, which allows clearance between the work piece in contact with the striker cutting edge and the shorter face, such that only the cutting edge directly contacts the work piece. A relatively larger diameter counterbore 52 than the diameter of bore 48 is machined in central alignment with bore 48 to a counterbore depth which is at least the height H of keys 50 . Counterbore 52 eliminates the machining difficulty of squaring the inside corners of keys 50 where the keys 50 intersect bore 48 . This ensures mating alignment between keys 50 and slots 46 for the entire height H of keys 50 . Key width W is machined on striker retainer 22 for the tight clearance fit with slots 46 discussed herein. Bore 48 is shown vertically off center of striker retainer 22 in FIG. 7, to provide a desired clearance of the bore from the retainer base 6 .
[0046] [0046]FIG. 8 is an alternative embodiment of a striker having a cutting edge 54 rotated 90 degrees compared to cutting edges 12 of FIG. 3, and including the cruciform slots of the present invention.
[0047] In use, slots 46 in striker 20 mate with the keys of striker retainer 22 such that motion between the mating faces of striker 20 and striker retainer 22 is minimized and alignment is assured. While connecting the striker 20 to striker retainer 22 , the head of a hex bolt 28 is matingly positioned in hex machined opening 30 . The bolt 28 connects with nut 24 . Bolt 24 extends through clearance bore 44 in striker 20 and through bore 26 , to threadably engage with hex nut 24 . Torquing hex nut 24 to bolt 28 mechanically fastens striker 20 and striker retainer 22 .
[0048] When the first of striker 20 cutting edges 12 becomes dull through use, nut 24 is removed, striker 20 is lifted away from striker retainer 22 until the slots 46 and keys 50 no longer engage, and striker 20 is rotated 180 degrees and its slots 46 re-mated to keys 50 of striker retainer 22 . Nut 24 and bolt 28 are then re-threaded and torqued to complete the reassembly. If both cutting edges 12 of striker 20 become dull from use, and resharpening or replacement of striker 20 is required, the above steps to remove and reassemble striker 20 are applied, eliminating the rotation step.
[0049] It is desirable to rotate a sharp cutting edge 12 into position by loosening, but not totally removing, nut 24 from bolt 28 . This prevents loss of either or both nut 24 and bolt 28 , and speeds up this maintenance evolution.
[0050] The preferred embodiment of the invention includes cruciform shaped, or two (2) perpendicular slots, mating with two (2) perpendicular raised keys. Other forms of slot and key attachment are feasible, including but not limited to a single slot and mating key, more than two slots and mating keys, and slot/key combinations machined transversely. It will be understood that the use of at least one slot and key combination provides a face to face horizontal locking means between the striker and striker retainer which enables use of a single fastener or fastening technique to be applied to positively join the faces of the striker and striker retainer of a comminuting device.
[0051] It should also be understood that the items receiving the slot and key may be reversed. In the claimed invention, the striker may therefore have a raised key or keys in place of the female slot(s), and the striker retainer may have a slot or slots in place of the male key(s). The raised keys, if more than one is employed, would then be counterbored as noted herein. Other aspects of the claimed invention would remain similar to those described herein.
[0052] Referring now to FIGS. 9, 10 and 11 , an alternative embodiment of striker 20 and striker retainer 22 is shown in which, when assembled together (FIG. 9), an upward facing surface 56 on the retainer 22 provides primary support for the striker 20 by virtue of the engagement of the surface 56 with a corresponding surface 58 machined in the striker 20 . This primary support is facilitated by the provision of a clearance 60 (e.g. 0.010 inch) between the machined key 50 a of the striker retainer 22 and the corresponding slot 46 a in the striker, this clearance 60 is between the upwardly facing surface of the key 50 a and the downwardly facing surface of the slot 46 a (as seen in the orientation of the assembly in FIG. 9).
[0053] The key 50 a and slot 46 a are designed to provide a secondary support for the striker when wear of the striker 20 sufficient to reduce the clearance 60 to zero has occurred.
[0054] To facilitate this embodiment the key 50 b is foreshortened.
[0055] The striker 20 is attached to the striker retainer 22 by a threaded bolt 62 extending from the following face 64 of the striker retainer through a single bore 66 to attach the striker 20 to the striker retainer 22 by the use of bore 68 having a thread corresponding to the thread of the bolt 62 . To prevent damage to the threaded bore 68 and the end of the bolt adjacent the first face 70 of the striker 20 , the threaded bore 68 is preferably terminated to form a blind bore which does not extend to the first face 70 of the striker.
[0056] Preferably the striker 20 has carbide surfaces as shown by cross-hatching in FIG. 11.
[0057] Except as described with reference to FIGS. 9, 10 and 11 the other features of this embodiment are similar to the embodiment described with reference to FIGS. 2 - 7 and will therefore not be described again here.
Reference Numerals 2 rotor 4 retainer carrying face 6 retainer base 8 striker 10 striker retainer 12 striker cutting edge 14 rotor rotation 16 rotor axis 18 projection 20 modified striker 22 modified striker retainer 24 nut 26 bore 28 bolt 30 hex machined opening 32 weld joint 34 bolt 35 countersunk bore 36 threaded bore 38 alternative striker 40 bolt 42 striker arc 44 clearance bore 46, 46a slot 48 bore 50, 50a, 50b raised keys 52 counter bore 54 striker cutting edge 56 upward facing surface 58 corresponding surface 60 clearance 62 threaded bolt 64 following face 66 single bore 68 threaded bore 70 first face D slot depth H key height X slot width W key width | A comminuting striker assembly for mounting on a rotor of a comminuting apparatus comprising: a striker having first and second opposed faces, the first face defining at least one cutting edge, and a striker retainer, the striker and striker retainer defining cooperating primary support surfaces and cooperating alignment components. | 1 |
TECHNICAL FIELD OF THE INVENTION
This invention relates to articles which are useful as a dry erase board and a projection screen, as well as methods of making the same. More specifically, the invention relates to articles which have a dry erasable topcoat with a specific gloss and a pigmented layer.
BACKGROUND OF THE INVENTION
Office environments are usually occupied with a writing board such as a chalk or dry erase board and a projector screen. Businesses are often changing their facilities to accommodate changes in personal and business needs. Often rooms are redesigned to provide conference rooms which were once personal office space. Conference rooms previously contained both a writing board and a projection screen. It is desirable to provide a single article which can meet the need for the writing surface and projection screen.
Dry erase boards have been used as a writing surface for years because of their convenience and versatility. The boards provide a means for expression which eliminates the mess and trouble of a chalk board. These boards however are not useful as projection surfaces because of the glare associated with the surface of the dry erase board. If the ordinary dry erase board was used as the projection surface the glare and reflection of the projection bulb leads to eye strain and fatigue to the viewers.
It is desirable to have a multi functional article which acts effectively as a dry erase board and a projection screen.
U.S. Pat. No. 5,200,853, issued to Berkman, relates to a board for screening and writing and a method for the production thereof. The patent discloses a durable multipurpose screening board which comprises an upper section comprising at least two superposed layers of transparent overlay sheets, each of the sheets weighing between 2 and 120 grams per square meter and having been soaked in a solution or melt of a polymeric resin material to subsequently form an intermediate solid plastic layer, the upper surface of the upper sheet being roughened by a plurality of closely-spaced complementary depressions of the depth between 0.01 mm and 0.2 mm, the core section comprising a paper sheet weighing between 60 and 140 grams per square meter and having soaked in a solution or melt of a polymeric resin material to subsequently form an intermediate solid plastic layer.
U.S. Pat. No. 5,361,164, issued to Steliga, relates to a projection markerboard. The markerboard has a bi-directional lenticular embossed surface. The light reflecting writing surface is preferably made of a thin film of fluoropolymer, such as a modified copolymer of ethylene and tetrafluoroethylene.
SUMMARY OF THE INVENTION
The invention relates to an article, useful as a dry erasable substrate and projection screen, comprising a top layer which is dry erasable and whose surface has a 60° gloss of less than about 60. The article provides a projection surface which has low gloss and therefore causes little eye strain and viewer fatigue. The dry erase board provides good write/ rewrite characteristics, erasability, including wet erasability and has good image projection. The article may additionally have one or more of layers which include a pressure sensitive adhesive, support layer, a pigmented layer which is a pressure sensitive adhesive or a pigmented polymer or polymer blend, and a back coat which is optionally pigmented.
BRIEF DESCRIPTION OF THE INVENTION
FIG. 1 is a cross section of a dry erasable article useful as a projection screen.
FIGS. 2-3 are a cross sections of a multilayer dry erasable articles useful as a projection screen.
FIG. 4-7 are cross sections of a dry erasable articles which contain glass beads and which are useful as a projection screen.
DETAILED DESCRIPTION OF THE INVENTION
As described herein the present invention relates to a dry erasable article which is also useful as a projection screen. The article has a surface which provides dry erasable characteristics.. The surface will provide a non beading surface where dry erasable ink is easily removed with mechanical pressure from an eraser, rag or towel. The surface has a 60° gloss of less than about 60. In one embodiment, the surface has a 60° gloss from about 10 to about 50, or from about 25 to about 40. The gloss is determined by ASTM D523-85 test procedure. In one embodiment, the surface has a roughness of about 2000 to about 13,000, or from about 3,000 to about 12,500, or from about 7,500 to about 11,000 angstroms. The roughness is determined by profilometer.
The surface, in one embodiment, has a hardness sufficient to withstand the mechanical pressures of marking and movement around a business environment. The surface typically has a pencil hardness of about 2H to about 6H, or about 4H. Dry erasable ink is easily removed from the surface without any residual ink remaining. The ink that remains typically is referred to as shadowing. In one embodiment, the surface is smooth. In another embodiment, the surface is other than a lenticulated surface.
The dry erasable surface is found on the top layer of the article of the present invention. The top layer comprises a polyurethane, a melamine resin, a polyester, a polyacrylate, polymethacrylate, a polyolefin or blends of two or more thereof. The top layer typically has a thickness from about 0.25 to about 5, or from about 0.75 to about 2, or about 1.5 mil.
In one embodiment, the top layer comprises at least one polyurethane. The polyurethane is prepared by reacting at least one isocyanate and at least one polyol. The polyurethane is prepared by reacting from about 0.5 to about 2, or from about 0.9 to about 1.85, or about 1.05 NCO to each OH.
In one embodiment, the polyurethane is derived from a polyisocyanate and a polyfunctional active hydrogen compound. The polyisocyanates may be any of the known polyisocyanates, such as aliphatic or aromatic polyisocyanates, used to form urethane resins.
The polyisocyanates useful in preparing the polyurethanes used in the present invention may generally correspond to the formula
Q(NCO) x (I)
in which x is at least 2 and Q represents a di-, tri-, or tetravalent-aliphatic hydrocarbon group containing from 2 to 100 carbon atoms, and 0 to 50 heteroatoms or a cycloaliphatic hydrocarbon group containing from 4 to 100 carbon atoms and 0 to 50 heteroatoms, or a substituted or non-substituted aromatic group. The heteroatoms that can be present in Q include non-peroxidic oxygen, sulfur, non-amino nitrogen, halogen, silicon and phosphorus.
Examples of polyisocyanates represented by Formula I include ethylene diisocyanate, 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate (HDI), 1,12-dodecane diisocyanate, cyclobutane, 1,3-diisocyanate, 1-isocyanato-3,3,5-trimethyl-5-isocyanato methyl cyclohexane, bis(4-isocyanato cyclohexyl)methane, isophorone diisocyanate (IPDI), bis(4-isocyanatocyclohexo)methane; 4,4′-methylenedicyclohexyl diisocyanate; 1,6-diisocyanato-2,2,4,4-tetramethylhexane; 1,6-diisocyanato-2,4,4-trimethylhexane; cyclohexane-1,4-diisocyanate; etc. Desmodur H® from Bayer Inc. is described as HDI having an NCO content of 50%, and Desmodur W from Bayer Inc. is described as bis(4-isocyanato-cyclohexyl)methane containing 32% of NCO.
Higher molecular weight polyisocyanates also are useful and are often preferred because the diisocyanates are toxic and raise industrial hygiene concerns. Examples of polyisocyanates include adducts, prepolymers and isocyanate trimers. For example, the trimethylol propane adducts of the various monomeric isocyanates such as HDI and isophorone diisocyanate (IPDI) are useful. Biurets of the diisocyanates also are useful and are commercially available. For example, the biuret of HDI is available as Desmodur N from Bayer Inc. Desmodur N-75 and Desmodur N-100 are examples of commercially available biuret of HDI, and Desmodur Z-4470 is a biuret of IPDI. Both of these materials are available from Bayer Inc.
Diisocyanates also can be converted to trimers that contain an isocyanurate ring. Trimers of HDI are available commercially from Bayer under the trademarks Desmodur N-3300 and Desmodur N-3390.
The polyfunctional active hydrogen compounds which may be reacted with the polyisocyanates include polyols, polyether polyols, polyester polyols, hydroxy-terminated polyesters, acrylic polyols, polyester amides, polycaprolactone polyols, etc. Polyester polyols and polyether polyols are preferred, and the polyols may comprise diols, triols, and combinations thereof. Polyether polyols are prepared by the polymerization of alkylene oxides with suitable initiators having active hydrogens in their structure. Examples of polyether diols include poly(oxyethylene)glycols and poly(oxypropylene)glycols. Examples of polyether triols include poly(oxypropylene)triol which are prepared by the base-catalyzed reaction of propylene oxide with low molecular weight triols such as trimethylol propane, glycerol, and 1,2,6-hexane triol.
Polyester polyols also are useful in preparing the polyurethanes useful in the present invention. Polyester polyols are generally prepared by reacting one or more dicarboxylic acids such as adipic acid, glutaric acid, sebacic acid, suberic acid, azelaic acid, dodecanoic acid, succinic acid, cyclohexane dicarboxylic acid, phthalic acid, isophthalic acid, hexahydrophthalic acid, dimerized linoleic acid (“Dimer” acid), and/or their corresponding anhydrides with one or more diols and triols. Mixtures of the dicarboxylic acids also can be used. The glycols which are used in the preparation of the polyester polyols generally include ethylene glycol, 1,2-propylene glycol, 1,3-propanediol, 2-methyl-1,3-propanediol, 1,3-butylene glycol, 1,4-butylene glycol, 1,6-hexanediol, diethylene glycol, neopentyl glycol, and diethylene glycol. The triols are usually glycerine, 1,2,6-hexane triol, Trimethylol propane, and trimethanol ethane. In some instances, pentaerythritol may be used.
In one embodiment, the polyol is at least one acrylic polyol. The acrylic polyol polymer preferably has a hydroxyl number of about 50 to about 300 or from about 75 to about 200 or about 80 to about 170, and a molecular weight of about 1,000 to 20,000 or from about 2,000 to about 10,000, or from about 400 to about 7,000. The hydroxyl number can be determined by any art-recognized method such as by theoretical calculation or by analytical methods. The acrylic polyol polymer is prepared by polymerizing one or more hydroxyl functional alkyl acrylate or methacrylate monomers and up to about 80 percent by weight ethylenically unsaturated non-hydroxyl functional monomers, based on the weight of the acrylic polyol. Suitable hydroxyl functional alkyl acrylate or methacrylate monomers include hydroxyethyl acrylate and methacrylate, hydroxypropyl acrylate and methacrylate, hydroxybutyl acrylate and methacrylate, and the like. Suitable ethylenically unsaturated non-hydroxyl functional monomers include alkyl and aryl acrylates and methacrylates having 1 to 16 carbon atoms in the alkyl or aryl groups as are known to those skilled in the art. Other suitable ethylenically unsaturated non-hydroxyl functional monomers include styrene, methyl styrene, acrylamide, acrylonitrile, and the like. Examples of useful acrylic polyols include Reactol 100 (hydroxl number 100, molecular weight 4,500, and equivalent weight 560) and Reactol 180 (hydroxyl number 160, molecular weight 5,000, and equivalent weight 340) available from Lawter International, Inc.
The polyurethane is prepared by means know to those in the art. Polyurethanes, isocyanates, polyols, and methods of making polyurethanes are disclosed in U.S. Pat. No. 5,514,441 Pohto, et al. This patent is hereby incorporated by reference.
The top layer may contain other conventional additives such as color stabilizers, inhibitors, antioxidants, ultraviolt absorbers, pigments, extenders, plasticizers, flatting agents, fillers, etc. These materials are known to those in the art. Although fillers such as silica can be included in films. The flatting agents act to control gloss and are generally present in an amount from about 0.5% to about 10%, or from about 2% to about 8% by weight. Flatting agents include those additives used in paints for controlling the matte of the finish. These additives include diatomaceous earth, Gasil Silica, Syloid Silica, wax, mica, Propylmatte family, AEROSIL, Cab-O-Sil, BUSAN flatting agent, etc.
The top layer also may contain at least one non-reactive solvent such as toluene, ethyl acetate, butyl acetate, PM acetate, etc. The amount of solvent present may vary over a wide range, but the amount of solvent generally will be in the range of from 0% to about 70% by weight and more often from about 20% to about 35% by weight. The actual amount of solvent required will vary with selected processing methods.
The following examples provide general and specific illustrations of the top layers described above.
EXAMPLE A
Range
Components
(weight)
Part A
Polyol
15-55
UV Stabilizers
0.5-2
Solvents
balance
Flow Agents
0.1-1.5
Inhibitor
0.1-1
Catalyst
0.005-0.1
Flatting agent
1-10
PART B
Diisocyanate
Part A
50-95
Part B
50-5
NCO/OH Ratio
0.8-1.2
EXAMPLE B
Components
Weight (g)
Part A
Acrylic polyol 1
47.09
Stabilizer
1.32
PM Acetate
14.13
Butyl Acetate
6.42
Polyacrylate flow
0.28
modifier
Cellulose acetate
0.24
butyrate
2,4 Pentanedione
0.35
Dibutyl Tin Sulfide
0.02
Silicone gel (5%
6.75
water)
PART B
1,6 Hexamethylene
Diiisocyanate
Part A
78.86
Part B
21.14
NCO/OH Ratio
1.05
1 acrylic polyol having a hydroxyl number of 160, and equivalent weight of 340 and a molecualr weight of 5000
EXAMPLE C
Components
(Parts by weight)
Part A
Acrylic polyol of Ex. B
46.88
Stabilizer
1.32
Polyether modified dimethylpolysiloxane
0.69
2,4 Pentanedione
0.33
PM Acetate
20.88
Dimethyl, methyl(polyethylene oxide)
0.53
siloxane (78 wt %),
Cellulose acetate butyrate
0.23
Dibutyl Tin Sulfide
0.03
Silicone gel (5% water)
4.13
Butyl Acetate
3.96
PART B
1,6 Hexamethylene Diiisocyanate
Part A
79.0
Part B Isocyanate
21.0
NCO/OH Ratio
1.05
When the dry erasable layer is pigmented, then the dry erasable layer may be used an a monolayer erasable article and projection film. As illustrated with FIG. 1, article 10 has film layer 11 , such as a polyurethane film which is pigmented to provide reflection and a surface 12 with a 60° gloss of less than 60. The pigment may be any pigment which provides the reflectance in the film. For instance, calcium carbonate, titanium dioxide may be used to provide reflectance. In one embodiment, the pigment is a color other than white such as grey, biege, etc. The pigments are know to those in the art.
In another embodiment, the dry erasable projection article is a multilayer structure with a top layer providing the dry erase character and another pigmented layer for providing reflectance of the image from the projector. The pigmented layer may be directly below the dry erase layer or may be separated from the dry erase layer by one or more intermediate layerS. The pigmented layer may be an adhesive or polymeric layer. The pigmented layer may be separated from the dry erase layer by one or more layers of transparent adhesives or polymers.
In reference to FIG. 2, article 20 is useful as a dry erasable projection screen. The article has a top layer 21 which has a dry erase surface 22 . The dry erase top layer 21 is adhered to adhesive 23 . The adhesive layer may be any adhesive which will secure the dry erase film to a substrate. Conventional pressure-sensitive adhesives, such as acrylic-based adhesives, or heat- or solvent-activated adhesives are typically used and may be applied by conventional procedures. These materials may be permanent or removable pressure sensitive adhesives. These materials include acrylic polymers, acrylic esters, silicones, polyvinyl esters, rubbers and urethanes. The adhesive may be a solvent or emulsion based rubber or acrylic adhesives such as those that are available in the art. These pressure sensitive adhesives include those such as Aroset® resin (an acrylic-based pressure sensitive adhesive) available commercially from Ashland Chemical and Gelva® adhesive available commercially from Solutia.
In another embodiment the pigmented adhesive layer is separated from the top layer by a polymeric layer. The polymeric layer is typically clear but may contain pigments. Referring to FIG. 3, article 30 has top layer 31 with dry erase surface 32 and adhered to polymeric layer 33 . Polymeric layer 33 may be directly in contact with top layer 31 or may be connected through one or more tie layers. The tie layers may be any of the above described polymers. In one embodiment the tie layer is a polyester or polyurethane tie layer. The adhesive layer 34 is adhered to polymeric layer 33 and may also have a release liner releasably adhered thereto, such as a silicone release layer.
In another embodiment the dry erasable projection article has a pigmented polymer layer. The pigmented polymeric layer may be directly adherred to the dry erase layer or may be bonded to the dry erase layer through a clear adhesive layer. The resins that may be used for the polymeric layer include a variety of partially amorphous or semi-crystalline thermoplastic polymers. Acrylics, polyvinylbutyrals, polyurethanes and polyesters are particularly useful. Copolymers of ethylene and an acrylic acid or methacrylic acid; vinyls, fluoropolymers, polyethylenes, cellulose acetate butyrate, polycarbonates and polyacrylates are other examples of polymers that can be used for the pigmented polymeric layer.
Of course, it is recognized that additional layers of adhesive and polymeric layers, either transparent or pigmented, may be used for structural support and aesthetic reasons. For instance in FIG. 3, additional combinations of layers 33 and 34 , such as a second combination of a polymeric layer and adhesive may be adhered to the polymeric 33 .
In another embodiment, the dry erasable projection screen contains a bead matrix layer. The bead matrix layer comprises one or more polymers and glass beads. The glass beads provide improved light management, such as light gain, for the projection aspects of the article. Typically the glass beads are characterized as having an average refractive index in the range of about 1.8 to about 2.5, or from about 1.9 to about 2.4, or from about 2.1 to about 2.3 and an average diameter of about 35 to about 100, or from about 45 to about 90, or from about 55 to about 80 microns.
Glass microspheres are typically used although ceramic microspheres such as those made by sol/gel techniques can also be used.
The bond matrix layer also contains a polymeric resin. Various thermoplastic polymeric resins have been used previously in forming the bead matrix layer, and such resins can be used in the pigmented polymeric layer of the present invention.
Referring to FIG. 4, dry erase, projection article 40 , has top layer 41 , with dry erase surface 42 . Top layer 41 is adhered to bead matrix layer 43 containing glass beads 44 . The bead matrix layer is thinner than the average diameter of the glass beads. Typically the thickness is from about 0.5 to about 3, or from about 0.75 to about 2 mils.
The bead matrix layer may be adhered to a pigmented layer, such as those discussed above. Referring to FIG. 5, article 50 with top layer 51 , with dry erase surface 52 , is adhered to bead matrix layer 53 having glass beads 54 . The bead matrix layer 53 contacts pigmented layer 55 which is either a pigmented adhesive or a pigmented polymeric layer. The pigmented polymeric layer may be adhered to the bead matrix layer through another adhesive layer.
The dry erase construction may also have a support layer. The support layer provides structural integrity to the dry erase construction. The support layer is typically a layer of one or more of the polymers described above for the pigmented layer. Polyvinylchloride is an example of a material which could be used as in the support layer. The support layer typoically has a thickness from about 1 to about 5 mil. Further illustration of the support layers of the article is found in reference to FIG. 6, which has article 60 with top layer 61 with dry erase surface 62 . The top layer is adhered to bead matrix layer 63 containing glass beads 64 . The bead matrix layer 63 is also adhered to pressure sensitive adhesive 65 , which in turn is releasably adhered to release liner 66 .
Another construction is shown in FIG. 7 where article 70 has top layer 71 with dry erase surface 72 . Top layer 71 is adhered to bead matrix layer 73 containing glass beads 74 . The bead matrix layer is adhered to pressure sensitive adhesive 75 which is also adhered to polymeric layer 76 . Polymeric layer 76 is also adhered to another adhesive layer 77 that in turn may be releaseably adhered to a release liner (not shown). The either adhesive layer or polymeric layer may pigmented. More than one of these layers may be pigmented as well.
The following examples relate to the dry erase projection film of the present invention.
EXAMPLE 1
A dry erase projection article is prepared by casting the urethane composition of Example B over the top of a bead matrix layer of glass microspheres and polyvinylbutyral. The urethane is cured for approximately 5 minutes at temperatures ranging from about 160° F. to 250° F.
EXAMPLE 2
The urethane composition of Example C is cast on 3 mil PET film as shown in FIG. 2 . The dry erase, projection construction gave the following results.
1. Dry eraseablity:
Immediately erase after ink drys— excellent
Erase after 7 days aging at room temperature—
excellent
Erase after 7 days aging at 140° F.—excellent
2. 60° gloss:
52 to 58
3. Hardness:
4H
4. Roughness:
2860 to 3320 angstroms
EXAMPLE 3
The top layer of Example 2 is adhered to a polyvinylbutyral layer containing glass beads (2.1 R.I. and an average diameter of 50 microns). The polyvinylbutyral layer is adhered to a 1.5 mil white PVC film by acrylic pressure sensitive adhesive. The construction gave the following test results.
1. Dry eraseablity:
Immediately erase after ink drys—excellent
Erase after 7 days aging at room temperature—
excellent
Erase after 7 days aging at 140° F.—good, after
using cleaner—excellent
2. 60° gloss:
26 to 34
3. Hardness:
4H
4. Roughness:
8600 to 10800 angstroms
5. Light gain:
1.6 at 0° view angle (head on), 1.0 to .95 at ±10° to
±70° view angles
EXAMPLE 4
Example 3 was repeated except that the polyvinylbutyral layer is adhered to a cool grey colored PVC film. The construction gave the following test results.
1. Dry eraseablity:
Immediately erase after ink drys—excellent
Erase after 7 days aging at room temperature—
excellent
Erase after 7 days aging at 140° F.—good, after
using cleaner—excellent
2. 60° gloss:
26 to 34
3. Hardness:
4H
4. Roughness:
8600 to 10800 angstroms
5. Light gain:
1.45 at 0° view angle (head on), 1.0 to .85 at ±10°
to ±70° view angles
While the invention has been explained in relation to its preferred embodiments, it is to be understood that various modifications thereof will become apparent to those skilled in the art upon reading the specification. Therefore, it is to be understood that the invention disclosed herein is intended to cover such modifications as fall within the scope of the appended claims. | The invention relates to an article, useful as a dry erasable substrate and projection screen, comprising a top layer which is dry erasable and whose surface has a 60° gloss of less than about 60. The article provides a projection surface which has low gloss and therefore causes little eye strain and viewer fatigue. The dry erase board provides good write/rewrite characteristics, erasability, including wet erasability and has good image projection. The article may additionally have one or more of layers which include a pressure sensitive adhesive, support layer, a pigmented layer which is a pressure sensitive adhesive or a pigmented polymer or polymer blend, and a back coat which is optionally pigmented. | 1 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to the repair of vinyl and leather, and more particularly to the repair and apparatus for repairing damage to vinyl and leather using plastisol repair compound.
[0003] 2. Description of the Prior Art
[0004] Vinyl and leather are widely used for furniture, seats for land, water and air vehicles, clothing and in a tremendous variety of other areas. Vinyl and leather are often subject to considerable wear and are often damaged in that they incur holes, slits, tears and rips. It is well known in the industry to repair vinyl and leather using plastisol. Plastisol is a polyvinyl heat curing component consisting of a mixture of a PVC resin and a plasticizer that can be molded, cast or made into a continuous film by the application of heat. In addition, plastisol may also include a coloring pigment. For example, Leatherize™ vinyl repair compound is a commonly employed plastisol. A plasticizer is well known, and is a chemical added specifically to rubbers and resins to impart flexibility, workability or stretchability. The conventional method and product for repairing vinyl and leather involves filling the damaged spot, which could be a hole or a slit, with a plastisol compound having the color of the product to be repaired. The plastisol is covered with a grained paper, and the grained paper is heated with a household iron or other vinyl repair heating tool. The object of this repair procedure is to provide a repaired product having the color and grain of the original vinyl or leather and be substantially as strong.
[0005] However, the present method of using plastisol is inappropriate for satisfactorily making the repair. The plastisol must be cured in order for it to assume the strength, wearability and to remain in place in the damaged area. When enough heat is applied to promptly cure the plastisol, it often happens that the heat is also applied to the undamaged area surrounding the damage to the vinyl or leather and the undamaged area loses its grain. The excessive heat applied to the plastisol further melts part of the vinyl or the coating on the leather and is, therefore, unsightly. In order to protect the surrounding vinyl or leather, less heat is often applied to the plastisol. However, although the repaired material looks better, the plastisol compound is not properly cured and is therefore weak and prone to damage. Therefore, an improved method and apparatus of applying and curing a plastisol compound to vinyl, leather and the like for repair of the vinyl, leather and the like is needed.
SUMMARY OF THE INVENTION
[0006] An object of the invention is to provide a repair system for repairing damage to vinyl and leather using a process yielding stronger results than the prior system of using plastisol compound.
[0007] Another object of the invention is to provide a method for repairing damage to vinyl and leather using conventional materials to yield a faster, longer-lasting and stronger result.
[0008] Still another object of the invention is to provide a method for repairing holes, slits, rips and tears in vinyl or leather yielding results having the original grain and color of the vinyl or leather, in a faster method and yielding stronger results than the conventional method of using plastisol to make the repair.
[0009] A yet further object of the present invention is to provide an improved method for repairing damaged vinyl or leather that is fast, efficient and economical.
[0010] Still yet another object of the of the present invention is to provide a method for repairing damage to vinyl and leather using conventional materials and that requires the use of heat application at a lower temperature than other conventional methods.
[0011] Still yet a further object of the present invention is to provide a method for repairing damage to vinyl and leather using conventional materials in lesser amounts than is used with conventional methods.
[0012] Other objects of the invention may occur to those of ordinary skill in the art upon reading of the following specification and the appended claims.
[0013] The foregoing objects are achieved according to the preferred embodiment of the invention wherein a polyurethane film is applied across the hole, slit, rip or tear in the vinyl or leather and grain paper is applied thereon and heated. After heat application, the grain paper is removed. Subsequently, plastisol is applied to the damaged portion of the vinyl or leather to which heat is applied again. The heat should be a high enough temperature to properly cure the plastisol, but not be of sufficient magnitude to damage the surrounding vinyl or leather.
[0014] In another version of the preferred embodiment, a polyurethane film is applied to one side of the vinyl or leather with grain paper placed thereon, heated and removed as indicated above. Plastisol is applied to sit on the film, and a further polyurethane film is applied on the other side of the vinyl or leather to form a sandwich construction. A heating tool is then applied to the film and plastisol of sufficient magnitude to cure the plastisol, the heat being of insufficient temperature to damage the vinyl or plastisol.
[0015] Another variation on the preferred embodiment is to apply more than one layer of polyurethane to increase the strength of the repairing product. In some situations involving slits, rips or tears to vinyl or leather, the invention involves the mere application of a polyurethane film, and the heating of the film in the manner indicated above for a short period of time, such as about 10 seconds, to secure the engagement of the film to the vinyl or leather. A secure repair is accomplished without the necessity for using plastisol, and the repair site is often not visible.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] [0016]FIG. 1 is a perspective view of a piece of vinyl or leather having a film applied over damage to the vinyl or leather;
[0017] [0017]FIG. 2 is a cross section of vinyl or leather having a film applied across the damaged area, and a heating tool being applied to the vinyl or leather;
[0018] [0018]FIG. 3 is a cross section of a piece of vinyl or leather having a damaged area, with plastisol in the damaged area, and polyurethane film applied to one side of the vinyl or leather across the damaged area, and a heating tool moving across the damaged area;
[0019] [0019]FIG. 4 is a cross section of a piece of vinyl or plastic having plastisol in the damaged area, and two layers of polyurethane film extending across the damaged area;
[0020] [0020]FIG. 5 is a cross section of a piece of vinyl or leather, with plastisol in the damaged area and polyurethane film on both sides of the damaged area;
[0021] [0021]FIG. 6 is a perspective view of a piece of vinyl or leather with polyurethane film extending over a slit, tear or rip in the vinyl or leather; and
[0022] [0022]FIG. 7 is a perspective view of the reverse side of the vinyl or leather shown in FIG. 6.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0023] [0023]FIG. 1 shows a piece of vinyl or leather 1 having damage in the form of a hole 2 located therein. In order to repair the hole according to the present invention, a polyurethane film 4 , such as Leatherize™ polyurethane film, is provided over the damaged area 2 , preferably on the top of the vinyl or leather. The polyurethane film 4 is preferably between one and ten mils thick. The polyurethane film 4 is easily softened and can be attached to vinyl or leather upon the application of sufficient heat. Referring to FIG. 1, polyurethane film 4 is supplied over the damaged area. A first thin layer of a vinyl repair compound (i.e. plastisol) is preferably applied around the edges of the damaged spot to help ensure that the polyurethane layer 4 will affix to the spot sufficiently. Of course the aforementioned thin layer of plastisol can be either clear or colored. Then, as shown in FIG. 2, a layer of grain paper 16 is placed over the polyurethane layer 4 and an iron or other heating tool 6 is passed over film 4 and layer 16 for about 10 seconds to attach film 4 over damaged area 2 , thereby forming a pocket-like structure in the damaged area 2 . Grain paper layer 16 is removed after the application of heat. The polyurethane layer 4 , after receiving sufficient heat treatment, bonds the sides of the damaged area 2 together and fills at least part of the damaged area 2 so that less of the repair compound needs to be used.
[0024] After the polyurethane layer 4 is heated and secured, a thin layer of a plastisol repair compound 8 , such as Leatherize™ vinyl repair compound, is spread over the polyurethane layer 4 , as shown in FIG. 3. The plastisol layer 8 may include a colored compound being the same color as the leather or vinyl surrounding the damaged area 2 . A second thin layer of grain paper 17 is then placed on the plastisol layer 8 , thereby sandwiching the plastisol layer 8 therebetween. Heating tool 6 is subsequently passed over the top of the grain paper 17 , thereby heating all three of polyurethane layer 4 , plastisol layer 8 and grain paper 17 . The heating effectively cures the plastisol layer 8 without causing damage to the surrounding leather or vinyl. Grain paper is commonly used in the art and imparts its grainy texture, upon being heated, into both the plastisol layer 8 and the polyurethane layer 4 . Grain paper 17 is easily removed by simply peeling it off the damaged area 2 after the final heat application. It is preferred that heating tool 6 is used to apply direct heat to the damaged area 2 at a temperature of about 300-350° F. and for about 10-15 seconds, preferably 10 seconds. Since the heat required to cure plastisol 8 or to secure polyurethane film 4 to vinyl or leather 1 is less than the heat necessary to damage the vinyl or leather portion surrounding damaged area 2 , one can apply sufficient heat to cure the plastisol and to secure the film without damaging the vinyl or leather. In addition, it should be appreciated that the initial heating application of the polyurethane film may be omitted and just one heating application in order to cure the plastisol may be employed.
[0025] Referring now to FIG. 4, in order to increase the strength of the polyurethane film, one can add a second layer of polyurethane film 10 on top of polyurethane film 4 and attach both layers to vinyl or leather 1 in the manner described above. Plastisol layer 8 is applied after grain paper 16 (not shown in FIG. 4) is removed and a layer of grain paper 17 is placed thereon. A heating tool 6 is used to cure the plastisol layer 8 as described above. In order to provide an additional support to the damaged area, it is also possible to add a second layer of polyurethane film 12 on the plastisol layer 8 before the layer of grain paper 17 is applied, to sandwich the plastisol 8 between the layers 4 and 12 , as shown in FIG. 5. In order to make the foregoing arrangement, one would apply polyurethane layer 4 to one side of the vinyl or leather 1 over the damaged area 2 , apply heat, in the manner described above, to attach or secure the layer 4 to the vinyl or leather 1 , and apply plastisol 8 in the damaged area to rest on the first layer of polyurethane film 4 . Another layer of polyurethane film 12 is then applied above the layer of plastisol 8 , with a layer of grain paper 17 applied thereon. The various layers are heated by heating tool 6 , as described above, and the layer of grain paper 17 is subsequently pulled away. The repair job as shown in FIG. 5 is as strong or stronger than the original undamaged material.
[0026] Sometimes the damaged area can be a slit, tear or rip in the vinyl or leather 1 . Referring to FIG. 6, a slit, tear or rip 14 is shown. Side 20 of vinyl or leather 1 is shown having the slit, tear or rip 14 . Over this, a layer of polyurethane film 18 is applied as shown and secured in the same manner as described above. Of course, the application of a plastisol layer and a grain paper layer, or even an additional polyurethane layer, in the manner as explained above, may also be included.
[0027] Alternatively, a one-step process could be used for a relatively smaller damaged area whereby layer 18 is applied, plastisol 19 is applied thereon, and a layer of grain paper 22 is applied, all of which are heated. Layer 22 is then removed. If one were to view the repaired vinyl or leather as shown in FIG. 7, one would find that there is no visible sign of the slit, tear or rip on the finished side 20 of vinyl or leather 12 .
[0028] It can thus be seen that the present invention provides a fast yet very inexpensive way to repair damaged vinyl or leather using low-cost, easily available materials using a simply-to-use process. Accordingly, such damaged areas as school bus seats, car seats, or other leather/vinyl products, as well as a variety of other items can easily be repaired in a strong yet not readily noticeable repair job. Kits could be provided having the necessary raw materials, i.e., plastisol and polyurethane film, so that nearly any person could make the repairs as required.
[0029] The invention has been described in detail with particular emphasis on the preferred embodiments thereof, and variations and modifications may occur to those skilled in the art to which the invention pertains from the foregoing application, drawings and the appended claims. | A method and apparatus for repairing damaged vinyl or leather wherein polyurethane film covers the damaged area and is heated. Plastisol is inserted in the damaged area and a layer of grain paper is applied thereon. Heat is again applied at a temperature to sufficiently cure the plastisol but to not damage the material surrounding the damaged area. | 1 |
BACKGROUND OF THE INVENTION
The present invention is concerned with a seat recliner fitting for the motor-driven inclination adjustment of a backrest and for the motor-driven folding out and folding in of a two-part leg support.
Known fittings of this type consists of a multitude of individual elements and assemblies that must be installed into a recliner frame and to the armrest, backrest, seat and leg support elements, as well as to one another.
SUMMARY OF THE INVENTION
It is the object of the present invention to create a substantially simpler furniture fitting that is exceedingly simple to install on the furniture elements.
This object is met in such a way that the fitting is completely pre-installed at the factory between two lateral plates, which are connected to cross-members and to which each side panel provided with an arm rest is attached, that each lateral plate has seat fitting linkage arms directly or indirectly linked to it, to which a mounting angle is linked to attach a seat frame along the length of which it approximately extends, and the leg support components are linked by means of scissor-type linkages directly or indirectly as support fitting linkage arms, which carry the leg supports on the respective angle pieces and a mounting plate to hold a backrest frame is directly or indirectly linked to the mounting angle, and that a backrest cross bar is disposed between the mounting plates on both sides, and a seat cross bar is disposed between the mounting angles on both sides, and a drive member of a backrest adjusting motor extends between this seat cross bar and the backrest cross bar, and that a scissor-type cross bar extends between the two scissor-type linkages, with a drive member for a leg support drive motor extending between this scissor-type cross bar and one of the cross-members, or that the drive member for the leg support motor extends between a cross-member and a cross bar that is disposed between the mounting angles.
Advantageous embodiments will be specified in the subclaims.
The skeletal structure that supports the entire linkage and drive means and also carries the backrest, seat, and supporting elements to be mounted thereon, consists of the two outer lateral plates to which the side parts with the arm rests are to be attached, and of the interposed cross-members that are rigidly connected to the former. The linkage arms are made of flat steel, partly shaped with an offset bend to the extent that a narrow clearance is required and disposed near the plates, and the mounting angles and angle pieces extend inward with their assembly legs to receive the seat frame or the plate-shaped leg supports. The skeletal structure also incorporates the drive means with the motors.
The drive forces are transferred from the motors via cross bars to the given fitting pieces that are symmetrically disposed on both sides and movable, either directly or indirectly, by means of cross bars. The drive means are provided preferably in the form of spindle motors, which can be connected very easily.
The entire skeletal structure is held at its lateral plates in supporting side panels, which carry the arm rests and side padding. A separate base frame for the piece of furniture can be eliminated, as all remaining furniture elements, i.e., the backrest, seat and leg support plates are held on and fastened to the skeletal structure. The lateral stability of the piece of furniture, in addition to the cross-members, also results from the cross bars and from the furniture elements that extend from side fitting to side fitting and which are screwed on with rigid angles.
The cross-members and bars are preferably made of tubing that is inserted into matching cutouts and connected therein releasable or rigidly, e.g., by welding.
Owing to a suitable execution of the scissor-type linkage arms and a linking of the leg support closest to the seat to the lower front scissor-type linkage section on one hand, and via an auxiliary linkage to the lower scissor-type linkage section closest to the seat on the other hand, the two leg supports are situated to one another in such a way that the leg supports in their extended position are situated in one plane behind one another and in their retracted position approximately vertically behind one another, with the inner support plate extending between the scissor-type linkages and the wider outer support plate closing off the front face below the seat. The support plates may be covered with suitable padding or upholstery fabric, so that they are an integral component of the visual seat design.
An advantageous wide overhang of the leg supports is attained by long scissor-type linkage members that are directly or indirectly linked to the lateral plates closely underneath the seat and that extend close to the floor when they are being pivoted. The total pivoting angle of the inner scissor-type linkage arms is approximately 145°. They are situated in one and the same plane of the scissor-type linkage mechanism so that low moments of force occur in the support points. The front linkage arms of the scissor-type linkage mechanism are each located to both sides of the rear linkage arms and to both sides of the associated connecting leg of the angle piece, which closes off the scissor-type linkage mechanism. One of the front scissor-type linkage arms, preferably the outer one, is designed wide enough so that it always overlaps the other one at least to a certain degree so that there is no danger of a person's fingers or the like getting caught during a readjustment of the scissor-type linkage mechanism. This wide design of the scissor-type linkage arm additionally also provides a high degree of stability to support the weight when the leg support is extended.
Each of the seat mounting angles is linked directly or indirectly to the lateral plate by means of a short seat fitting linkage arm in the front and a longer one in the rear. These seat linkage arms extend upward. The front linkage arm is connected to a leg support fitting linkage arm and is adjusted together with the same by means of the leg support adjusting drive. The seat is accordingly coupled to the leg supports in such a way that the seat linkage arms are positioned nearly parallel when the leg supports are extended and slanted forward when the leg supports are retracted, so that the seat is lowered more in the front in this position and remains essentially at an unchanged height in the back during any adjustment. Since the backrest is linked to the seat mounting angle in the rear area and the backrest adjusting drive is situated between the seat and the backrest, the respective given backrest position relative to the seat remains unaffected by any adjustment of the leg support, which displaces the seat and backrest together approximately horizontally.
In a first embodiment the mounting angle of the seat and the mounting plate of the backrest are connected to one another in articulated fashion at a mounting angle extension, which is disposed at approximately half the height of the seat and backrest between the same, close to the backrest padding. As a result the two padding elements lie close against one another in the sitting position and move apart in the reclined position only by a measure corresponding to half of the padding thickness. The hinges and mounting components that are installed laterally close to the padding elements are sufficiently recessed downward in the gap in order not to have any interfering effect.
In a second embodiment, the mounting angle and the mounting plate are connected in each case to a scissor-type backrest linkage, the linkage arm of which is designed and linked in such a way that the backrest padding and seat padding always touch in the upper region when the backrest is being readjusted and no gap occurs between them. To connect the lower linkage arm closest to the seat, the seat mounting angle has a downward facing extension. The upper scissor-type linkage arm closest to the seat is connected close to the lower rear end of the seat above the other scissor-type linkage arm.
In a further improvement of the second embodiment, the scissor-type backrest linkages are implemented as a multi-part scissor-type linkage, thus permitting advantageous adaptations of the movements to different types of padding. This permits, in a particularly advantageous fashion, the contact of the backrest and seat padding with one another along the entire adjustment range of the backrest almost completely without the padding elements sliding on one another, thus preventing increased wear and tear in the contact areas.
In a third embodiment, the leg supports are adjusted via the movement of the seat frame and the motor is fastened on a cross-member and its adjusting spindle moves the seat frame back and forth via a pivoting lever that engages in the rear seat frame area. The coupling of the seat frame in the front region to the leg support fitting linkage arms accordingly permits the adjustment of the leg supports. In this advantageous system the cross bar between the leg support linkage arms is eliminated and permits a larger degree of freedom in this area.
Advantageous embodiments are presented in FIGS. 1 - 8 :
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a side view of a chair in the reclined position with the side panel removed, partly in the view I—I;
FIG. 2 is an assembled longitudinal view of a fuel injector according to an embodiment of the present invention, showing a sectional view upon the injection;
FIG. 3 is a top view showing another support portion of a cylindrical member;
FIG. 4 is an assembled longitudinal view of a portion of a fuel injector according to an alternative embodiment of the present invention, showing the second and third cylindrical members of the embodiment depicted in FIG. 1 formed as one pierce; and
FIG. 5 is an assembled longitudinal view of a portion of a fuel injector according to an alternative embodiment of the present invention, showing the third and fourth cylindrical members of the embodiment depicted in FIG. 1 formed as one piece.
FIG. 6 shows a backrest with scissor-type linkage in the sitting position;
Fig. 7 shows a reclined position for the chair in FIG. 6 , partially in the view VII—VII;
FIG. 8 shows a top view on the fitting in FIG. 7 ;
FIG. 9 shows a chair similar to FIG. 6 and 7 , in an intermediate position with a multi-part scissor-type linkage mechanism to link to the backrest, and a different position of the leg support drive;
FIG. 10 shows a linkage variant between the seat frame and leg support fitting linkage in a section enlargement of the area X of FIG. 9 ;
FIG. 11 shows a view A—A according to FIG. 10 in a section;
FIG. 12 shows a top view of the fitting in FIG. 9 .
DETAILED DESCRIPTION
FIG. 1 shows a chair in a reclined position in a side view, which has one side panel removed and whose side panel 42 , shown in the back of the figure has a complete sub-assembly screwed to it that consists of symmetrical fitting assemblies, which are congruent in the figure and each of which is held on a lateral plate 4 of which the one that is located covered in the back of the figure is screwed to the side panel 42 . Since the lateral fitting assemblies are symmetrical, identical reference numerals will be used throughout for matching pieces. Extending between the lateral plates 4 are sturdy cross-members 40 , 41 , as shown in FIG. 2 , which are designed tubular, welded into matching plate recesses, or otherwise connected removable or rigidly.
In the front and rear area of the plate 4 a seat fitting linkage 24 , 34 A is connected in each case, to the other end of which a mounting angle 20 is linked in each case, to the inwardly pointing leg of which a seat frame of a seat is screwed. The mounting angle 20 is connected to its laterally reversed counterpart by means of a sturdy seat cross bar 22 .
On the rear, a mounting angle extension 20 A extends from the mounting angle 20 upward to approximately half the height of the seat padding, with a fitting plate linked to the mounting angle extension 20 A as a mounting plate 10 for the backrest 1 or for a backrest frame, to which it is laterally screwed in multiple locations. Said backrest linkage joint 23 on the mounting plate 10 is located some distance below the surface of the backrest padding. Below this backrest linkage joint 23 a backrest cross bar 12 is disposed, extending from mounting plate 10 to mounting plate.
On this backrest cross bar 12 and on the seat cross bar 22 , a backrest adjusting motor is linked by means of a drive member 13 , preferably a spindle.
When the adjusting spindle 13 pushes the bars 12 , 22 apart, the seat 2 is pushed forward on the seat mounting angle 20 while being supported on the short front linkage arm 34 A. When the bars 12 , 22 are pushed apart, the backrest 1 is swiveled upward with the mounting plate 10 , as shown in various phases in FIGS. 3 and 4 . In the swiveled-up seat position the seat padding and backrest padding sit closely against one another. The front seat linkage arm 34 A extends beyond its plate joint into the upper scissor-type linkage arm 34 of the support fitting linkages closest to the seat and is adjusted together with its drive.
In the resting position shown in FIG. 1 , the backrest 1 is tilted back slightly rising and the seat padding 2 is slightly tilted back and displaced by a hand's width toward the backrest 1 , however, a gap of a few centimeters width remains between the two padding elements.
In front of the seat surface, on a somewhat lower level, the surfaces of two leg supports 3 A, 3 B extend flush with one another and are linked on both sides to leg support fitting linkage arms 34 - 38 ,in each case via angle pieces 30 A, 30 B to which they are screwed, with the leg support fitting linkage arm consisting of an auxiliary linkage arm 38 and scissor-type linkage mechanism 34 - 37 , which is linked at its other end to the lateral plate 4 . The scissor-type linkage mechanism 34 - 38 has relatively long levers that extend approximately from the seat to the floor when the scissor-type linkage joint passes approximately through its lowest point during a pivoting process, as can be derived from FIGS. 3 and 5 , which show an intermediate position and the retracted position of the leg supports 3 A, 3 B.
The front leg support 3 B in its retracted position is positioned vertically and extends at its top to within a close distance underneath the frame of the seat 2 with a small clearance and at its bottom to a few centimeters above the floor. In the cross direction it closes the entire front region between the chair side panels 42 , as shown in FIG. 2 , with a small clearance on the sides.
The rear leg support 3 A in its folded-in position is located approximately parallel to the front leg support at a distance from the same to leave space for the padding. The lateral extension of the rear leg support 3 A is somewhat smaller than that of the front leg support, as shown in FIG. 2 , to leave space on the sides for the scissor-type linkage and the flange of the angle pieces 30 A, 30 B.
To permit the rear leg support 3 A to swivel from its vertical position into the approximately horizontal supporting position according to FIG. 1 when the scissor-type linkage mechanisms are actuated, the downward pointing leg of the angle piece 30 A is linked both to a front scissor-type linkage arm 36 and also with an auxiliary linkage 38 to a rear scissor-type linkage arm 35 . The view of the leg support fitting linkages 34 - 38 in FIG. 1 corresponds to a view I—I from the center of FIG. 2 onto the above-drawn fitting.
As shown by FIG. 2 , the rear scissor-type linkage arms 34 , 35 are disposed above one another close to the lateral plate 4 and the front scissor-type linkage arms 36 , 37 are disposed to the right and left of the them. This narrow design of the scissor-type linkage mechanism prevents the occurrence of twisting moments.
The outer front scissor-type linkage arm 37 is approximately twice as wide as the others. It thus has a much higher section modulus and no gap forms between the front scissor-type linkage arms in any readjustment position of a size that would allow a finger to get caught. The rear scissor-type linkage arms 34 , 35 are spaced far enough apart even in their closest position, which is shown in FIG. 1 , so that fingers can be placed between them and there is no danger of them getting caught.
FIGS. 6 through 8 show a second embodiment of the backrest coupling that takes place via scissor-type linkage gears 14 - 17 . The projections in FIGS. 6 and 7 are derived from the section VI—VI; the lateral plates and the rear seat linkage arm are not shown for ease of viewing.
FIG. 6 shows the backrest 1 in the upright position and FIG. 7 shows it in the completely reclined position. The padding of the backrest 1 and seat 2 are in contact in all positions, no interfering gap is formed into which loose padding elements or pieces of clothing could be drawn or become wedged.
The seat fitting 20 has a downward facing mounting angle extension 20 B to which the scissor-type linkage arms 14 , 15 closest to the seat are linked at a distance above one another offset behind one another. The scissor-type linkage arms 16 , 17 closest to the backrest are directed upward and linked to the former on one hand and linked, spaced apart above and behind one another, to a mounting plate 10 B and connected via the same with the backrest 1 to its frame.
As shown in FIG. 8 , the backrest cross bar 20 B, to which the backrest adjusting motor 11 is connected, is shaped with an offset bend. The backrest cross bar 20 B extends between mounting plates 10 B. These as well as all backrest drive elements and the scissor-type backrest linkage gears are situated under the seat padding and backrest padding in all positions of the backrest, and on the sides these padding elements extend close to the chair side panels.
FIG. 9 shows a chair in a further exemplary embodiment of the scissor-type backrest linkages 14 - 17 and leg support drive 31 , 33 . The scissor-type backrest linkage arms 14 , 15 , 16 , 17 , together with additional scissor-type backrest linkage arms 15 A, 16 A, form a multi-step scissor-type linkage mechanism in the style of lazy tongs. The backrest 1 is shown in its upright position.
The scissor-type linkage arm 15 closest to the seat is connected pivoting to the scissor-type linkage arm 16 closest to the backrest, and the scissor-type linkage arm 14 is connected via two additional scissor-type linkage arms 16 A and 15 A to the scissor-type linkage arm 17 closest to the backrest. In this embodiment the scissor-type linkage arm 16 closest to the backrest is situated at a distance from the scissor-type linkage arm 17 closest to the backrest. This results in an advantageous option to adapt the movement of the backrests to different frames so that the padding elements of the backrest 1 and seat 2 are again advantageously in contact in any position in such a way that no gap occurs.
The motor 31 of the leg support adjusting drive is linked to the cross-member 40 , its leg support adjusting spindle 33 is connected pivoting to a cross bar 22 A. The cross bar 22 A is situated between two pivoting levers 43 and connected to the same. The pivoting levers 43 are pivot mounted on the two lateral plates 4 and connected pivoting at their upper ends to the mounting angles 20 . During a readjustment of the leg support adjusting spindle 33 , for example in the direction toward the foot end, this direction of movement is reversed by the pivoting levers 43 so that the mounting angles 20 move in the opposite direction. In the front area of the mounting angles 20 the leg support fitting linkages 34 are linked in a coupled fashion and, in the process, extend the leg supports 3 A, 3 B. The leg supports 3 A, 3 B are thus adjusted indirectly via the movement of the mounting angles 20 . It is advantageous in this context that the cross bar 32 is eliminated and more space is created to retract the leg supports 3 A, 3 B.
FIG. 10 shows, in an enlarged section of the area X according to FIG. 9 , the coupling of the mounting angle 20 to the leg support fitting linkage arm 34 via a pin 44 . The leg support fitting linkage arm 34 has, for this purpose, an angled extension with a slotted hole 34 B, which is connected to the pin 44 and, hence, to the mounting angle 20 . It is particularly advantageous to use a slotted hole since significantly lesser drive forces are thus required to adjust the leg supports.
FIG. 11 shows a view of the section A—A in FIG. 10 . The slotted hole 34 B is provided with a low-friction design, for example in the form of a sleeve 34 C. In this sleeve 34 C, the pin 44 , which also has a sleeve 34 , is guided in a low-friction manner. The material for the sleeves 34 C, 34 D is preferably plastic.
In an advantageous arrangement, the seat fitting linkage arms 34 A, leg support fitting linkage arms 34 , and mounting angle 20 are connected in a linking point by means of the pins 44 so that they are pivotable in relation to one another.
FIG. 12 shows a top view of the fitting according to FIG. 9 .
To facilitate the installation of the seat frame 2 on the mounting angle 20 , a plurality of centering pins 18 and additional round screw holes 19 are provided in the same. The seat frame can thus be inserted with the centering pins ( 18 ) into matching centering holes and held in position while the securing screws are screwed in through the screw holes 19 .
The backrest frame and side panels are pre-drilled with templates or provided with bolts or threaded inserts so that the backrest and lateral plates can easily be screwed together there in an accurate position.
To facilitate the installation of the seat frame 2 and/or seat side panels 42 , the mounting angles and/or lateral plates 4 are preferably entered into the centering pins 18 , causing them to be received in matching bores and held centered and in the correct position.
List of Reference Numerals
1 Backrest (Backrest Frame)
2 Seat (Seat Frame)
3 Leg Supports
3 A Leg Supports
3 B Leg Supports
4 Lateral Plates
10 Mounting Plate
10 B Mounting Plate-with Scissor-Type Linkage Joint
11 Motor for 1
12 Backrest Cross Bar for 11 / 1
12 B Backrest Cross Bar with an Offset Bend on the Scissor-Type Linkage Joint
13 Adjusting Spindle in 11 (Drive Member)
14 Backrest Scissor-Type Arms
15 , 15 A Backrest Scissor-Type Arms
16 , 16 A Backrest Scissor-Type Arms
17 Backrest Scissor-Type Arms
18 Centering Pins
19 Screw Holes
20 Mounting Angle for 2
20 A Mounting Angle Extension
20 B Mounting Angle Extension for Scissor-Type Linkage Joints
22 Seat Cross Bar
22 A Cross Bar
23 Backrest Linkage Joint
24 Seat Fitting Linkage Arm, Rear
30 Angle Piece
30 A Angle Piece for 3 A
30 B Angle Piece for 3 B
31 Motor for 3 A, 3 B
32 Cross Bar for 31
33 Leg Support Adjusting Spindle in 31 (Drive Member)
34 Leg Support Fitting Linkage Arm, Rear
34 A Seat Fitting Linkage Arm, Front
34 B Slotted Hole
34 C Sleeve
34 D Sleeve
35 Leg Support Fitting Linkage Arm—Scissor-Type Linkage Arm
36 Leg Support Fitting Linkage Arm—Front Side
37 Scissor-Type Linkage Arm
38 Auxiliary Linkage Arm
40 Cross-members between 4
41 Cross-members between 4
42 Chair Side Panel with Armrest
43 Pivoting Lever
44 Pin | A seat-recliner fitting is provided for the motor-driven inclination adjustment of a backrest ( 1 ) and for the motor-driven folding out and folding in of a two-part leg support ( 3 A, 3 B), whereby the fitting is completely pre-installed at the factory between two lateral plates ( 4 ), which are connected to cross-members ( 40, 41 ) and to which each lateral wall ( 42 ) provided with an arm rest is attached. | 0 |
CROSS REFERENCE TO RELATED APPLICATION
This application claims priority to Indian Patent Application No. 0568/DEL/2005 filed Mar. 16, 2005, the entirety of which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of Invention
The present invention relates to an improved process for the preparation of crosslinked polyallylamine. More specifically the present invention relates to a process for crosslinking of aqueous polyallylamine dispersed in an organic medium so as to maximize the yield of crosslinked product in the desired particle size range of 60 to 100 mesh.
2. Background of the Technology
Polyallylamine is a polymer of allylamine. The amine group of the polymer can be functionalized further. The polymer finds a wide range of applications such as flocculants, coatings and additives. It is well known that the monomer mono allyl amine does not polymerize readily as it undergoes degradative chain transfer. Allylamine is therefore converted into its salt such as hydrochloride or sulfate and polymerized in the presence of a free radical initiator. The polymerization of salts of allylamine is described adequately in U.S. Pat. Nos. 6,303,723, 6,787,587, 6,579,933, 6,509,013, 6,083,495, 5,667,775, 5,496,545, which are cited herein by way of reference.
Polyallylamine hydrochloride solutions are then partly neutralized and crosslinked using a wide range of crosslinking agents described in U.S. Pat. Nos. 6,509,013, 6,083,495, 5,667,775, 5,496,545, 4,605,701, which are cited herein by way of reference. The crosslinkers typically used are epichlorohydrin, 1,4 butane diol diglycidyl ether, 1,2 ethane diol diglycidyl ether, 1,3 dichloropropane, 1,2 dichloroethane, succinyl dichloride, dimethyl succinate and toluene diisocyanate. More specifically the partly neutralized polymer of allylamine hydrochloride is crosslinked using epichlorohydrin.
The use of crosslinked polymer for binding phosphates and bile acids is disclosed in U.S. Pat. Nos. 5,496,545, 6,667,775, 6,083,495, 6,509,013, 6,696,087, 6,433,026, 6,423,754, 6,294,163, 6,203,785, 6,190,649, 6,083,497, 6,066,678, 6,060,517, 5,981,693, 5,925,379, 5,919,832, 5,969,090, 5,917,007, 5,840,766, 5,703,188, 5,679,717, 5,607,669.
The crosslinked polymers are formulated in tablets as described in U.S. Pat. Nos. 6,696,087 and 6,733,780. The methods of making phosphate binding polymers for oral administration are described in U.S. Pat. Nos. 6,509,013, 6,083,495, 5,496,545, 5,667,775, more particularly the U.S. Pat. Nos. 5,496,545, 5,667,775, 6,083,495, 6,509,013, 4,605,701, which are cited herein by way of reference.
According to the teaching of the U.S. Pat. No. 6,083,495, the method of crosslinking involves reacting for about 15 minutes polyallylamine with a difunctional crosslinking agent in an aqueous solution as to form a gel and allowing the gel to cure for 18 hours at room temperature. The gel is then fragmented into gel particles in a blender in the presence of isopropanol. The gel particles are then washed repeatedly with water and then suspended in isopropanol, filtered and dried in vacuum oven for 18 hours.
The process of crosslinking in aqueous solution described in above patents, leads to gelation. Curing at room temperature takes a long time. The gel is difficult to break into gel particles and needs application of high shear in special equipments. The gel particles swell when repeatedly extracted with water and need to be treated with isopropanol again prior to drying. The process also consumes large excess of water and isopropanol. The gel particles need to be dried in a vacuum oven for long time.
This is because polymeric gels adhere to each other and equipment surfaces. In order to overcome problems associated, drying is carried out in presence of additives, which are either azeotrope forming solvents or agents which influence surface wetting of the gel particles. The U.S. Pat. No. 6,600,011 describes the spray drying technique for drying of crosslinked polyallylamine, which is claimed to avoid damage to shear sensitive polymer gels, and also enables improved particle size control. The patent also describes the use of a Ystral three stage disperser to achieve the desired particle size.
Drying of the aqueous slurry by spray drying , needs careful control of the feed pressure and temperature. Especially the feed temperature depends on the nature of the feed in that the feed temperature has to be below the glass transition temperature of the hydrogel and needs to be so adjusted as not to degrade the hydrogel. The U.S. Pat. Nos. 6,362,266 and 6,180,754 describe a process for producing a crosslinked polyallylamine polymer having reduced cohesiveness. According to the teachings of the said patents the crosslinking reaction is carried out in a specially designed reactor, which can handle highly viscous solutions and can break the gel into small pieces after gelation. Typically a LIST-Discotherm B reactor is suitable for carrying out the crosslinking reaction which generates easy to handle clumps of gel. The application of high shear is detrimental as it leads to the formation of soluble oligomers.
The dried crosslinked polymer is further ground using a mortar and pestle, a Retsch mill or a Fritz mill. The patents further describe that during the drying stage the hydrogel becomes highly cohesive, which leads to high power consumption to rotate the agitator. The addition of a surfactant is recommended to reduce the cohesiveness during drying. In summary, the crosslinking of polyallylamine in aqueous solution leads to gelation. The gel is then fragmented in blenders into gel particles, which are then treated with water and isopropanol and then dried. It is also reported that the application of high shear contributes to soluble oligomers, which are undesirable. Hence methods have been proposed to minimize the oligomer content in the final product. Also the use of specific equipments like LIST Discotherm B reactor has been suggested for carrying out crosslinking and spray driers for drying the crosslinked polymers. Especially spray drying is a critical operation in that the feed temperature has to be below the glass transition temperature of the crosslinked polymer.
The existing methods of crosslinking polyallylamine polymer need specialized equipments for converting the gel into gel particles and /or drying the gel particles formed.
The polyallylamine hydrochloride salt used for crosslinking in the present invention is reported extensively in the literature. More specifically the synthesis of the polyallylamine hydrochloride polymer is disclosed in the U.S. Pat. Nos. 6,083,495, 5,667,775, 5,496,545, 6,303,723, 4,605,701, 6,509,013, the disclosures of which are incorporated herein by reference.
The polyallylamine hydrochloride polymer used for crosslinking is partly neutralized prior to crosslinking. This is achieved by dissolving the polymer in water and by adding a calculated amount of alkali such as sodium hydroxide or potassium hydroxide either as a solid or as an aqueous solution.
U.S. Pat. No. 6,362,266 reports ion exchange, dialysis nano filtration or ultrafiltration as methods to remove the salt. In the crosslinking processes described in U.S. Pat. Nos. 6,509,013, 5,496,545, 5,667,775, 6,083,495 the salts are removed by extraction with water after the crosslinked polyallylamine polymer obtained in the form of gel is fragmented into gel particles by treatment with isopropanol in a blender. This process involves the treatment of gel mass in blenders in presence of solvents and is not easy to operate.
The process described by the present invention leads to the formation of gel particles, which can be more readily washed either with an organic solvent or water in order to extract the salts. Furthermore, the gel particles formed as a result of the process described herein, do not readily agglomerate and hence can be washed with water and solvent readily and can also be dried more easily.
The crosslinking agents used for the crosslinking of the polyallylamine hydrochloride are extensively described in the U.S. Pat. Nos. 6,362,266, 6,509,013, 5,496,545, 5,667,775, 6,083,495. In the above patents, the crosslinking agent is added to the partly neutralized polyallylamine hydrochloride at room temperature and the crosslinking reaction is allowed to proceed as such. In contrast, according to the procedure described in this invention, it is desirable to cool the neutralized polyallylamine hydrochloride solution in the range 4° C.-10° C. prior to the addition of the crosslinking agent so that the polymer solution does not undergo substantial crosslinking before the dispersion of the aqueous solution into the organic medium is complete and the dispersion of the aqueous phase in the organic phase is readily achieved. The dispersion of the aqueous phase comprising partly neutralized polyallylamine hydrochloride salt and crosslinking agent, in an organic medium is more readily achieved by incorporating a suitable surfactant such as SPAN 85 in the organic medium.
According to the teaching of the U.S. Pat. Nos. 5,667,775, 5,496,545, 6,083,495, 6,509,013, the aqueous polyallylamine solutions to which the crosslinking agent is added, gel in about 15 minutes and the gel is then allowed to cure for 18 hrs at room temperature. The gel is then broken into pieces by putting into a blender with isopropanol. While this treatment can be carried out on the scales described in these patents, these operations are more difficult to carry out on large scales. U.S. Pat. No. 6,362,266 describes the use of LIST-Discotherm B reactor to process high viscosity materials and break the gel into small gel particles.
According to the method of the present invention, the polymer solution containing the crosslinking agent is dispersed in an organic medium before substantial crosslinking takes place. Since the polymer solution is crosslinked in individual liquid droplets to form gel particles, which are suspended in an organic phase, the viscosity of the resulting dispersion is much lower than the viscosity of gel formed when crosslinking is carried out according to the methods previously reported in the literature. The crosslinking of polyallylamine hydrochloride as described herein can be readily carried out in conventional batch reactors provided with stirrers commonly used in the chemical industry.
U.S. Pat. No. 4,605,701 describes the use of chlorobenzene and dichlorobenzene as an organic solvent and a non ionic surfactant sorbitane sesquioleate. However, the use of chlorinated hydrocarbons is being discouraged in view of the environmental damage caused by the chlorinated hydrocarbons. Also high boiling points of solvents such as chlorobenzene and dichlorobenzene render the removal of solvents from the polymer difficult. Accordingly the present invention envisages the use of non chlorinated solvents as organic medium.
Further, the above patent claims the crosslinked homopolymer of monoallylamine having a particle size not more than 2 mm. However, the said patent does not deal any further with the particle size and its distribution and more particularly the importance of the particle size in relation to the properties and applications of the polymer in phosphate binding.
In a surprising development the inventors of the present invention have observed that the phosphate binding capacity of the crosslinked polyallylamine hydrochloride, which is indicative of the ability of the crosslinked polymer to bind with the phosphates in the body, also depends upon the particle size of the dried product. The crosslinking of the polyallylamine hydrochloride in the dispersion medium results in a distribution of the particle sizes. The coarse particles exhibit a lower phosphate binding capacity. The finer particles exhibit a higher phosphate binding capacity. While the coarse particle generated during the process can be further ground to yield product in the desired size range in 60-100 mesh, the grinding process also produces fines, which pass through a 100 mesh sieve. While the phosphate binding capacity of the fines is not significantly different than the particles in the size range 60-100 mesh, the fines are not particularly suitable for the preparation of tablets. It is therefore desirable that the crosslinking of polyallylamine hydrochloride be carried out under conditions wherein the particle size of the crosslinked product produced in the reactor is in the range 60-100 mesh, so that no further processing is required.
There is therefore a need to develop a method for the synthesis of crosslinked polyallylamine which will simplify the manufacturing method, minimize the need for specialized equipments, bring down the need for wash solvents and will thus bring down the manufacturing costs.
According to the method of the present invention, the crosslinking is carried out in the dispersion medium in the presence of a suitable surfactant and the choice of the stirrer and stirring speed such that the yield of the crosslinked product in the size range 60-100 mesh is maximized. If the yield of the product which passes through the 100 mesh sieve and which is retained over 60 mesh sieve is minimized, only a small portion of the product of the reactor will have to be subjected to size reduction and the loss of fines will also be minimum.
Objectives of the Invention
The main object of this invention is a simplified process for the synthesis of crosslinked polyallylamine hydrochloride.
Another object of this invention is to provide a process which could maximize the yield of the crosslinked polyallylamine hydrochloride having particle size distribution in the range 60-100 mesh.
Yet another object of this invention is to provide a process which avoids the need of specialized equipments for the manufacture of the said product and thus reduces the manufacturing cost.
SUMMARY OF THE INVENTION
The present invention provides a process for producing a crosslinked polyallylamine polymer directly in the form of the gel particles. The process comprises mixing a crosslinking agent with a chilled aqueous solution of partly neutralized polyallylamine hydrochloride, dispersing the aqueous solution in an organic solvent containing surfactant, maintaining the dispersion at room temperature , while stirring continuously, raising the temperature and maintaining the dispersion at this temperature so as to complete the crosslinking reaction, separating the gel particles from the organic medium, washing with water and finally with a solvent and drying the crosslinked polyallylamine. The method maximizes the yield of crosslinked polyallylamine hydrochloride particles in the size range 60-100 mesh.
DETAILED DESCRIPTION OF THE INVENTION
Accordingly the present invention provides an improved process for the preparation of crosslinked polyallylamine polymer having particle size in the range 60 to 100 meshs which comprises partly neutralizing polyallylamine hydrochloride in the range of 58 to 90% with an alkali in an aqueous solution, chilling the above said solution to a temperature in the range of 4 to 10° C., adding a crosslinking agent to the above said chilled solution and dispersing the resultant mixture in an organic solvent containing a surfactant, under agitation, at a speed of 800 to 1200 rpm, allowing the reaction to occur initially at a temperature in the range of 25-30° C., for a period of about 10 minutes and further increasing the reaction temperature to a maximum of about 80° C. and allowing the reaction to continue for at least three hours, cooling the above said reaction mixture to a temperature in the range of 25-30° C., filtering the above said reaction mixture to separate the gel particles, washing the above said gel particles with water and finally with a water miscible organic solvent and removing the excess solvent followed by drying under vacuum to obtain the desired crosslinked polyallylamine polymer.
In an embodiment of the present invention the alkali used is an alkali hydroxide. In another embodiment of the present invention the alkali hydroxide used is sodium hydroxide.
In another embodiment the surfactant used is commercially available SPAN-85. In yet another embodiment the concentration of the surfactant used is ranging between 0.25 to 1% (v/v) of the organic solvent.
In yet another embodiment the ratio of the aqueous phase to organic phase used is in the range 1:3.3 to 1:8.
In yet another embodiment the organic solvent used for dispersion is selected from aromatic and aliphatic hydrocarbon.
In yet another embodiment the organic solvent used for dispersion is aromatic hydrocarbon selected from the group consisting of toluene, xylene and ethyl benzene.
In yet another embodiment the organic solvent used for dispersion is aliphatic hydrocarbon selected from the group consisting of hexane, heptane, octane decane, dodecane and paraffin.
In yet another embodiment the organic solvent used for washing the crosslinked polyallylamine polymer is selected from alcohol, ketone and ester In yet another embodiment the organic solvent used is an alcohol selected from the group consisting of methanol, ethanol and isopropanol.
In yet another embodiment the organic solvent used is a ketone selected from the group consisting of acetone, methyl ethylketone, methyl isobutyl ketone. In yet another embodiment the organic solvent used is an ester selected from methyl acetate and ethyl acetate.
In yet another embodiment 70 to 90% of the crosslinked polyallylamine obtained has particle size distribution in the range of 60-100 mesh.
In still another embodiment the phosphate binding capacity of the crosslinked polyallylamine obtained is in the range 2.9-3.25 meq phosphate/g.
The novelty of the present invention lies in the preparation of controlled particle size crosslinked polyallylamine polymer having particle size distribution in the range of 60-100 mesh in high yield.
The invention is now described in details by reference to the following examples, which are purely illustrative in nature and shall in no way limit the scope of the invention.
EXAMPLE 1
15 g of polyallylamine hydrochloride of intrinsic viscosity 0.18 dl/g in 0.1 N NaCl solution was partly neutralized with aqueous solution of sodium hydroxide as shown in table 1 to convert part of amine hydrochloride to free amine. The resulting mixture was cooled to 5° C. To a jacketed kettle equipped with mechanical stirrer and condenser was added toluene (120 ml) and sorbitane trioleate (0.6 ml) (Span 85). Epichlorohydrin (1.8 ml) was added all at once to the partly neutralized polyallylamine hydrochloride solution. This solution was immediately dispersed in toluene with stirring. The mixture was heated to 60° C. and stirred for 3 hrs. Toluene was decanted. The crosslinked polyallylamine hydrochloride formed was washed 3 times by suspending in 150 ml of de-ionized water stirring magnetically for 45 min. followed by filtration. The crosslinked solid was rinsed once by suspending it in isopropanol (200 ml) stirring for 45 min followed by filtration. The solid was dried under vacuum for 8 hrs.
Table-1 illustrates the degree of neutralization and corresponding phosphate binding capacities of crosslinked polyallylamine hydrochloride polymers as a function of degree of neutralization.
TABLE 1
Sodium
Degree of
Phosphate binding
Sr. No.
Hydroxide (g)
neutralization (%)
capacity meq/g
A
3.8
59.2
3.87
B
4.2
65.4
3.17
C
4.8
74.8
2.42
D
5.3
82.5
1.55
E
5.7
88.8
0.89
EXAMPLE 2
15 g of polyallylamine hydrochloride was neutralized with aqueous solution of sodium hydroxide (4.2 g) to convert part of amine hydrochloride to free amine. The resulting mixture was cooled to 5° C. To a jacketed kettle equipped with mechanical stirrer and condenser was added toluene (120 ml) and sorbitane trioleate (0.6 ml) (Span 85). Epichlorohydrin (1.8 ml), was added all at once to the partly neutralized polyallylamine hydrochloride solution. This solution was immediately dispersed in toluene with stirring. The mixture was heated to 60° C.) and stirred for 3 hr. Toluene was decanted. The crosslinked polyallylamine hydrochloride formed was washed 3 times by suspending in 150 ml of de-ionized water stirring magnetically for 45 min. followed by filtration. The crosslinked solid was rinsed once by suspending it in isopropanol (200 ml) stirring for 45 min followed by filtration. The solid was dried under vacuum for 8 hrs.
Table 2 illustrates crosslinking of polyallylamine hydrochloride polymer differing in intrinsic viscosity.
TABLE 2
Sr. No.
Intrinsic viscosity dl/g
Phosphate binding capacity meq/g
A
0.18
3.17
B
0.20
3.12
C
0.22
3.12
D
0.24
2.98
EXAMPLE 3
15 g of polyallylamine hydrochloride was neutralized with aqueous solution of sodium hydroxide (4.2 g) to convert part of amine hydrochloride to free amine. The resulting mixture was cooled to 7° C. To a jacketed kettle equipped with mechanical stirrer and condenser was added toluene (120 ml) and sorbitane trioleate (0.6 ml) (SPAN 85). Epichlorohydrin, crosslinking agent was added all at once to the partly neutralized polyallylamine hydrochloride solution. This solution was immediately dispersed in toluene with stirring. The mixture was heated to 60° C. and stirred for 3 hrs. Toluene was decanted. The crosslinked polyallylamine hydrochloride formed was washed 3 times by suspending in 150 ml of de-ionized water stirring magnetically for 45 min. followed by filtration. The crosslinked solid was rinsed by suspending it in isopropanol (200 ml) stirring for 45 min followed by filtration. The solid was dried under vacuum for 8 hrs.
Table 3 describes crosslinking of polyallylamine hydrochloride using different quantities of epichlorohydrin.
TABLE 3
Sr. No.
Epichlorohydrin ml
Phosphate binding capacity meq/g
A
0.8
2.47
B
1.2
2.91
C
1.8
3.17
D
2.4
5.03
EXAMPLE 4
15 g of polyallylamine hydrochloride was neutralized with aqueous solution of sodium hydroxide (4.2 g ) to convert part of amine hydrochloride to free amine. The resulting mixture was cooled to 5° C. To a jacketed kettle equipped with mechanical stirrer and condenser was added toluene (120 ml) and sorbitane trioleate (0.6 ml) (SPAN 85). Epichlorohydrin (1.8 ml), was added all at once to the partly neutralized polyallylamine hydrochloride solution. This solution was immediately dispersed in organic solvent with stirring. The mixture was heated to 60° C. and stirred for 3 hrs. The organic solvent was decanted. The crosslinked polyallylamine hydrochloride formed was washed 3 times by suspension in 150 ml of deionized water stirring magnetically for 45 min. followed by filtration. The crosslinked solid was rinsed by suspending it in isopropanol (200 ml) stirring for 45 min followed by filtration. The solid was dried under vacuum for 8 hrs.
Table 4 describes crosslinking of polyallylamine hydrochloride carried out in different dispersion media.
In example D paraffin oil was decanted. Trace amount of paraffin oil was removed washing it with hexane. The crosslinked polyallylamine hydrochloride was washed 3 times by suspending in 150 ml of de-ionized water stirring magnetically for 45 min. followed by filtration. The crosslinked solid was rinsed by suspending it in isopropanol (200 ml) stirring for 45 min followed by filtration. The solid was dried under vacuum for 8 hrs.
TABLE 4
Sr.No.
Dispersion medium
Phosphate binding capacity meq/g
A
Toluene
3.17
B
Hexane
3.16
C
Xylene
3.22
D
Paraffin oil
3.18
EXAMPLE 5
15 g of polyallylamine hydrochloride was neutralized with aqueous solution of sodium hydroxide (4.2 g) to convert part of amine hydrochloride to free amine. The resulting mixture was cooled to 5° C. To a jacketed kettle equipped with mechanical stirrer and condenser was added toluene (120 ml) and sorbitane trioleate (SPAN 85). Epichlorohydrin (1.8 ml), was added all at once to the partly neutralized polyallylamine hydrochloride solution. This solution was immediately dispersed in toluene with stirring. The mixture was heated to 60° C. and stirred for 3 hrs. Toluene was decanted. The crosslinked polyallylamine hydrochloride was washed 3 times by suspending in 150 ml of de-ionized water stirring magnetically for 45 min. followed by filtration. The crosslinked solid was rinsed by suspending it in isopropanol (200 ml) stirring for 45 min followed by filtration. The solid was dried under vacuum for 8 hrs.
Table 5 describes crosslinking of polyallylamine hydrochloride using different amounts of surfactant (SPAN -85).
The particle size distribution of the product obtained and the phosphate binding capacities are summarized below:
TABLE 5
SPAN-85
% Above 60
Sr
Conc.
mesh
% 60-100 mesh
% Below100 mesh
No.
(%)
(meq PO 4 /g)
(meq PO 4 /g)
(meq PO 4 /g)
A
1
15.14
72.58
12.28
(2.23)
(2.96)
(3.22)
B
0.5
32.38
60.00
7.62
(2.38))
(3.0)
(3.31)
C
0.25
34.22
59.02
6.76
(2.57)
(3.18)
(3.26)
D
No
94.94
4.67
0.39
surfactant
(2.76)
(3.17)
(3.31)
The above data indicate the need to control the particle size distribution so as to maximize the yield of the product in the size range 60-100 mesh and minimize the yield of the product in the size range which passes through 100 mesh sieve.
EXAMPLE 6
15 g of polyallylamine hydrochloride was neutralized with aqueous solution of sodium hydroxide (4.2 g) to convert part of amine hydrochloride to free amine. The resulting mixture was cooled to 5° C. To a jacketed kettle equipped with mechanical stirrer and condenser was added toluene (120 ml) and 0.6 ml sorbitane trioleate (SPAN 85). Epichlorohydrin (1.8 ml), was added all at once to the partly neutralized polyallylamine hydrochloride solution. This solution was immediately dispersed in toluene with stirring using a stirrer, which has four blades at the bottom, two blades at the center and two blades above the blades at the center. The mixture was heated to 60° C. and stirred at a predetermined speed for 3 hrs. Toluene was decanted. The crosslinked polyallylamine hydrochloride formed was washed 3 times by suspending in 150 ml of de-ionized water stirring magnetically for 45 min. followed by filtration. The crosslinked solid was rinsed by suspending it in isopropanol (200 ml) stirring for 45 min followed by filtration. The solid was dried under vacuum for 8 hrs. The particle size distribution of the product obtained and the phosphate binding capacities are summarized below.
Table 6 describes the crosslinking of polyallylamine hydrochloride under different stirring conditions.
TABLE 6
% Above 60
% 60-100
% Below 100
Sr.
mesh
mesh
mesh
No.
RPM
(meq PO 4 /g)
(meq PO 4 /g)
(meq PO 4 /g)
A
800
58.36
39.19
2.45
(2.73)
(3.0)
(3.29)
B
1000
32.38
60.00
7.81
(2.38)
(3.0)
(3.31)
C
1200
19.2
70.6
10.20
(2.69)
(3.12)
(3.40)
The above data indicates that an optimal stirring speed results in maximizing the yield of crosslinked polyallylamine hydrochloride in the particle size range 60-100 mesh and minimizing the yield of fines which pass through 100 mesh sieve.
The advantages of the present invention are:
1) The present invention is a simplified crosslinking process. 2) The present invention provides a maximum yield of particles of crosslinked polyallylamine in the size ranging from 60-100 mesh. 3) The present process eliminates the need of specialized and expensive equipments for manufacturing and can be completed in shorter reaction time. | The present invention provides a process for crosslinking of polyallylamine hydrochloride wherein an aqueous solution of polyallylamine hydrochloride is partly neutralized with alkali and epichlorohydrin is added. The aqueous solution is dispersed in an organic medium containing a surfactant. This leads to gelation in individual droplets. The crosslinking in individual gel beads is completed by raising the temperature. The resulting beads are then separated, washed with water, treated with an organic solvent and dried. The method maximizes the yield of crosslinked polyallylamine hydrochloride particles in the range 60-100 mesh. | 2 |
[0001] This application claims priority to co-pending Canadian Application No. 2,438,160 filed Aug. 21, 2003. The entire text of the above application is incorporated by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a micronutrient supplement dispensing package. More specifically, the present invention is concerned with a micronutrient supplement dispensing package provided with safety features so as to avoid lethal or deleterious toxicity to a child should a child accidentally ingest the contents of the package as sold.
BACKGROUND OF THE INVENTION
[0003] Micronutrient compositions are commonly taken as dietary aids; either as therapeutic preparations directed to a specific medical problem or as general nutritional supplements. Micronutrients may be broadly defined as substances that are essential or helpful for the maintenance of normal or enhanced metabolic function, but are not normally or sufficiently synthesized in the body and must thus be supplied from an exogenous source.
[0004] Given poor dietary habits of individuals and other factors, it has become clear that the role of micronutrient compositions is substantial when it comes to preventing fatigue, disease and optimizing cell maintenance and development. This is particularly the case for individuals who lead a stressful lifestyle, for pregnant women or those who engage in a large amount of physical exercise. Additionally, many drugs, some chronic diseases (e.g. rheumatoid arthritis), certain cancer treatments, and alcoholism can all lead to a deficiency in one or more micronutrients.
[0005] It is has also been suggested that a significant portion of preventable illnesses (which it is estimated absorbs as much as 70 per cent of total health care costs in the United States) could be readily prevented through supplementing the diet with micronutrients. In addition to major health care cost savings other benefits of supplementation include better quality of life, longer life, and increased productivity. The level of supplements required for effective disease protection cannot be obtained through even the most healthful diet (Bendich, Adrianne, et al. Potential health economic benefits of vitamin supplementation. Western Journal of Medicine, Vol. 166, May 1997, pp. 306-12).
[0006] Micronutrients, including multivitamins and mineral supplements are especially important to pregnant or lactating women, ensuring an adequate provision of nutrients for the developing fetus and for the mother. It has become clear that the role of micronutrients is substantial when it comes to preventing fatigue, disease and optimizing cell maintenance and development.
[0007] However, one of the leading causes of preventable deaths among toddlers is the accidental ingestion of iron-containing micronutrient supplements such as vitamins and mineral supplements.
Source: The Merck Manual of Diagnosis and Therapy, 16 th edition, 1992, page 2128 Pediatrics and Genetics, Injuries, Poisonings and Resuscitation: under the heading “Iron Poisoning”, “The oral lethal dose of elemental Iron (Fe) is from 200 to 250 mg/kg, but as little as 130 mg of elemental Fe has been fatal.” Also see the Juurlink et al. “ Iron poisoning in young children: association with the birth of a sibling”, Canadian Medical Association Journal, June 10, 2003, 168 (12), in the Abstract: “Iron is a leading cause of death due to poisoning in young children. Because perinatal iron therapy is common, the presence of these tablets, which have a candylike appearance, in the home may pose a hazard to a mother's other young children.”
[0012] Pregnancy multivitamins and mineral supplements are particularly dangerous as they contain large amounts of iron. Typical prenatal products contain 60 mg of elemental iron per tablet. Juurlink et al., precited.
[0013] However, iron is an important ingredient of pregnancy supplements so as to prevent iron sufficiency and anemia during pregnancy. Iron insufficiency and anemia are characterized by poor transport of oxygen to tissues throughout the body via hemoglobin and myoglobin.
[0014] Toddlers are particularly at risk since they are by nature inquisitive, resourceful and capable of opening multivitamin containers. They tend to imitate gestures such as taking vitamins. Toddlers are also particularly at risk because of their sensitivity to iron poisoning. This sensitivity decreases with age.
[0015] Strikingly, a single bottle of the leading pregnancy multivitamin contains sufficient amounts of iron to lethally affect a young child. Most commonly sold pregnancy multivitamins and mineral supplements contain about 60 mg of elemental iron compound and are provided in 100 tablet bottles. This represents a total potential dose of 6000 mg or 6 grams. It is known that mild to moderate iron toxicity for toddlers starts as low as 20 to 60 mg/kg of body weight. 200-250 mg/kg of body weight is life threatening to lethal while at total ingestion of 6000 mg for a toddler will be lethal.
[0016] Surprisingly, little has been done in the prior art to address such terrible and preventable occurrence. So far, the prior art has provided micronutrient supplements, such as pregnancy multivitamins and mineral supplements, in bottles having childproof caps. However, if the mother does not screw a childproof cap tightly enough to engage the safety mechanism, a childproof cap will no longer be childproof.
OBJECTS OF THE INVENTION
[0017] An object of the present invention is therefore to provide a novel micronutrient supplement dispensing package which combines a plurality of childproof features.
SUMMARY OF THE INVENTION
[0018] More specifically, in accordance with an aspect of the present invention, there is provided a micronutrient supplement package provided in the form of a plurality of solid oral dosage units individually contained in blister packs wherein a portion of the dosage forms are iron-containing and at least half of the dosage units are essentially iron-free and wherein in a preferred embodiment the total amount of elemental iron in the package as sold to purchasers is less than about 1300 mg and most preferably 1050 mg or less of iron.
[0019] Other objects, advantages and features of the present invention will become more apparent upon reading of the following non-restrictive description of preferred embodiments thereof, given by way of example only with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Having thus generally described the invention, reference will now be made to the accompanying drawings, showing by way of illustration a preferred embodiment thereof, and in which:
[0021] FIG. 1 shows a perspective view of an example of a micronutrient supplement package of the present invention and more specifically an individual blister pack of a week's worth of the supplement of the present invention having an array of a first type of dosage unit which are iron-containing, to be taken at a given time of day, and an array of a second type of dosage unit which are essentially iron-free, to be taken at another time of day.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0022] In a most preferred embodiment, the invention discloses a micronutrient supplement in the form of two distinct dosage units to be taken at spaced time intervals. In other words, the dosage unit is provided as a twice-a-day formulation which a different dosage units taken at each time interval.
[0023] As a first childproofing feature, the dispensing package contains blister wrapped and two distinct types of dosage units and preferably present in equal numbers. Each type of dosage unit contain different constituents with one dosage unit containing iron and other ingredients while the other dosage unit being essentially iron-free. Thus, if a child should accidentally ingest dosage units, the child would have a 50% chance to avoid ingesting iron.
[0024] An added benefit of the two dosage units is that calcium and iron ingredients may be placed in distinct and different dosage units so as to avoid their known propensity to mutually interfere with each other's absorption by the body.
[0025] In a most preferred embodiment, the two types of dosage units would be taken at spaced time intervals, e.g. one in the morning and one in the evening. In this most preferred embodiment, the compositions of the dosage units would be as follows:
EXAMPLE 1
[0026] The following is an example of a morning dosage unit core formulation:
[0027] The following is an example of a morning dosage unit core formulation:
[0000]
TABLE 1
Core ingredients:
Item #
Ingredient
Label Claim
mg/Tab.
1.
Beta-carotene
2700
IU
2.
Vitamin E
30
IU
3.
Vitamin C
120
mg
4.
Vitamin B 1
3
mg
5.
Vitamin B 2
3.4
mg
6.
Vitamin B 3
20
mg
7.
Vitamin B 6
10
mg
8.
Pantothenic Acid
5
mg
9.
Magnesium
50
mg
10.
Iodine
0.15
mg
11.
Iron
35
mg
12.
Copper
2
mg
13.
Zinc
15
mg
14.
Cross carmellose
35
Sodium
15.
Sodium Lauryl
3.5
Sulphate
16.
Microcrystalline
180
Cellulose PH 102
17.
Starch 1500
55
18.
Magnesium
3.5
Stearate
[0028] The following is an example of an evening dosage unit core formulation:
[0000]
TABLE 2
Core ingredients:
Item #
Ingredient
Label Claim
Mg/Tab.
1.
Vitamin D 3
250
IU
2.
Calcium
300
mg
3.
Vitamin B 12
12
mcg
4.
Folic Acid
1.1
mg
5.
Cross carmellose
30
Sodium
6.
Sodium Lauryl
3
Sulfate
7.
Magnesium
3
Stearate
Dispensing Kit
[0029] Referring now to FIG. 1 , the preferred form of the present invention would be a dispensing kit containing two distinct dosage units grouped by type. Blister packs [ 10 ] of a week's worth of the supplement of the present invention having an array of blisters [ 12 ] of a first type of dosage unit to be taken at a given time of day and an array of blisters [ 14 ] of a second type of dosage unit to be taken at another time of day. Conveniently, 5 blister packs can be grouped in a box (not shown) for sale as monthly dosage packs. Advantageously, the package of dosage units will contain a 30 day supply, as four 7-day blister packs and one 2-day blister pack.
[0030] Still referring to FIG. 1 , the blister pack includes graphical means [ 16 ] and [ 18 ] permitting a pregnant woman to differentiate between the morning and evening dosage types. These means may be, for example, a color code or diagrams surrounding a particular array of dosage units of the same type be it morning or evening.
[0031] An important benefit of the individual blisters [ 12 ] and [ 14 ] for each dosage unit is that a child who accidentally obtains access to blister packs will have to open each blister to get to a dosage unit. This is in contrast to prior devices where once access to a container of dosage units was obtained by a child such as by defeating the safety features of a childproof cap, the entire contents of dosage units became immediately available. Thus, this is the second childproofing feature.
[0032] Advantageously, each blisters [ 12 ] and [ 14 ] will be of the type having a clear plastic bubble sealed with aluminum foil. Still advantageously, the foil will be of a gauge which is difficult to pry open by a small child. This provides yet another line of defense in childproofing in the package of the present invention.
[0033] As indicated above, another line of childproofing feature in the package of the present invention is the fact that half of the dosage units are essentially iron-free. Thus, even if a child opens a blister, even chances will be that the dosage unit will be iron-free.
[0034] Yet another line of childproofing feature in the package of the present invention is the fact that the entire package contents of the present invention total less than about 1300 mg of elemental iron and most preferably 1050 mg or less (35 mg per dosage unit times 30 days), which is clearly a sub-lethal dose even for a toddler of, for example, 10 kg. The dose in such case would be 105 mg/kg of body weight. Thus, advantageously the dispensing package contains, in total, less than about 1050 to 1300 mg of elemental iron.
[0035] In contrast, a leading prenatal commercial preparation of multivitamins and mineral supplement currently sold in Canada is bottles of 100 tablets each containing 60 mg of elemental iron or 6000 mg of elemental iron. If the contents of the bottle were ingested, a 10 kg toddler would receive a lethal dose of 600 mg/kg of elemental iron.
[0036] Although the present invention has been described hereinabove by way of preferred embodiments thereof, it can be modified, without departing from the spirit and nature of the subject invention as defined in the appended claims. | Provided herein is a prenatal and postpartum multivitamin and mineral supplement package provided in the form of a plurality of solid oral dosage units individually contained in blister packs wherein a portion of the dosage forms are iron-containing while at least half of the dosage units are essentially iron-free and wherein the total amount of iron in the package as sold to purchasers is less than about 1300 mg of elemental iron. | 0 |
TECHNICAL FIELD
The present invention relates to a tackable acoustical wall panel or board having excellent tackable properties, and which has a flame spread index which qualifies it as a Class A rated building material.
BACKGROUND OF THE PRIOR ART
The most commonly used materials to provide a tackable surface in an office environment are cork and compressed wood fiber. While such materials have excellent tack retention properties, they are very poor sound absorbers. What is more, they are not fire resistant, cork, for example, having a flame spread index of well over 100. Efforts to provide a tackable surface having improved properties, especially from the standpoint of sound absorption, have involved the use of high density fiberglass. However, as pointed out in U.S. Pat. No. 4,248,325, fiber glass is unsatisfactory as a tackable surface. In an attempt to overcome the shortcomings of fiber glass as a tackable surface, U.S. Pat. No. 4,248,325 discloses the use of a wire mesh screen positioned a distance between two layers of fiber glass such that a tack pin will pass through an opening in the screen when the pin enters one of the fiber glass layers. This arrangement, however, does not in any way alter the poor retention, or pull-out properties of the fiber glass layer in which the tack pin is positioned, and, therefore, the arrangement is unsatisfactory for supporting large, or heavy, prints, drawings, plans, maps, and the like.
BRIEF SUMMARY OF THE INVENTION
The tackable acoustical structure of this invention is characterized not only by its excellent tack retention properties, but, also by its surface burning properties which qualify it as a Class A rated building material. So far as can be determined, the structure of this invention is the only, and first, tackable structure so rated. More specifically in this latter connection, the structure of the present invention, when tested in accordance with the American Society for Testing and Materials Standard Test Method for "Surface Burning Characteristics of Building Materials", identified as ASTM E 84-81a, and also known as the Steiner Tunnel Test, had a flame spread index in the range of about 10 to about 20. In order for a material to receive a Class A rating under this test method, it must have a flame spread index of from 0 to 25.
In brief, the structure of this invention comprises a layer of a tack pin retaining material, a layer of an acoustical or sound absorption material, and a continuous layer or film of a metal foil. The combined thickness of the acoustical or sound absorption material and the metal foil is such that the pointed shank or pin of a tack can pass therethrough and enter the layer of the tack pin retaining material. In a preferred embodiment of the invention, the outer surface of the structure is provided with a decorative surface or facing. The structure advantageously is fabricated in the form of panels which are floor-to-ceiling in length, and which have a width such as to enable them to be easily handled by a single installer. An entire room can be panelled with the tackable panels to provide a sound proofed enclosure having total tackable surface area.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a front view in elevation of panels formed from the structure of the present invention being installed as floor-to-ceiling wall panelling in a room;
FIG. 2 is a fragmentary view in perspective of the back side of a panel of the type being installed as shown in FIG. 1;
FIG. 3 is an enlarged fragmentary view in perspective of a wall panel formed from the structure installed on a supporting wall surface; and
FIG. 4 is an enlarged fragmentary vertical sectional view of the structure of this invention with a tack positioned thereon.
DETAILED DESCRIPTION OF INVENTION
Referring, now, in particular, to FIGS. 3 and 4 of the drawing, the embodiment of the structure shown, and designated generally by reference numeral 10, comprises a tack pin retaining layer 12, a sound absorption layer 14, and a septum formed of a continuous layer, film or sheet of a metal foil 16 positioned between the layers 12 and 14. A decorative surface or facing 18 is provided on the exposed, or outer, surface of the sound absorption layer 14.
The tack pin retaining layer 12 can be fabricated from various materials, both organic and inorganic, having tack pin retention properties. An especially preferred material is wood fiber board. While the thickness and weight of the layer is somewhat variable, the generally optimum objectives of the invention are attained with a tack pin retaining layer having a thickness of about 3/8 inch to about 5/8 inch, preferably about 1/2 inch, and a weight ranging from about 0.5 to about 1.5, preferably about 0.8 pound per square foot.
The sound absorption layer 14 of the structure 10 can be formed from a number of acoustical, or sound absorbing, and fire resistant materials, including glass fibers, mineral wools such as slag or rock wool, as well as synthetic plastic filament or spun fibers, and mixtures of the foregoing. The preferred material is a glass fiber laminate which has been impregnated with an uncured, or partially cured, thermosetting bonding agent such as a phenolic resin. The thickness of the layer 14 advantageously is about 1/16 inch to about 3/16 inch, preferably about 1/8 inch. The density of the layer 14 desirably will be of the order of about 8 to about 16, preferably about 12 pounds per cubic foot.
The septum, or continuous metal foil layer, film or sheet 16 may be formed of aluminum or lead, aluminum being preferred. The thickness of the layer or film can range from about 0.5 mil to about 2 mils, preferably about 0.7 to about 1 mil.
The decorative facing 18 desirably is formed of an open-weave synthetic fabric which is inherently fire resistant, or which has been chemically treated to make it fire resistant. Preferred facing materials are woven, filament or spun plastic sheet materials such as polypropylenes, vinyls and polyesters, and glass fibers. Polypropylene based materials are preferred due to their self-sealing, or memory, properties. The weave of the facing should be such as to permit sound energy to easily pass through to the sound absorbing layer 14, and to not impede the passage of a tack pin into the structure. The thickness of the facing 18 advantageously is from about 1 mil to about 8 mils, preferably about 4 or 5 mils. As best shown in FIG. 2, the margins 18a of the facing 18 desirably cover the edges of a panel 20 formed from the structure to give the panel a finished appearance. The margins 18a can be adhered to the back surface of the tack pin retaining layer 12.
In those instances where the sound absorption layer 14 comprises glass fibers impregnated with an uncured, or partially cured, thermosetting bonding agent such as a phenolic resin, the facing 18 and the sheet or film of the metal foil 16 can be adhered to the layer 14 either separately, or simultaneously, by placing the layer 14, the facing 18 and the metal foil 16, between heated platens. Sufficient heat and pressure are applied to cure the bonding agent and to form the stacked materials into a rigid, integrated multi-ply sheet which can be adhered to the tack pin retaining layer 12. Any of a variety of adhesive materials can be employed to bond the metal foil film 16 to the layer 12. A preferred adhesive is a water based latex available commercially under the designation "EA 7601" (Borden).
In FIGS. 3 and 4 of the drawing, a conventional tack 22 is shown supporting a sheet 24 of informational material on the finished structure 10 of this invention. The tack pin 22a of the tack 22 has passed through the facing 18, the sound abosrption layer 14, the metal foil film 16, and is embedded in the tack pin retaining layer 12. As indicated hereinabove, the combined thickness of the facing 18, the layer 14 and metal foil film 16 is such that the tack pin of a standard or conventional tack can pass through them and penetrate the layer 12 a sufficient distance to firmly retain the tack in position on the structure irrespective of the weight or size of the informational material tacked to the structure.
While the structure of this invention can be formed into wall panels of any desired dimensions, panels measuring 4 feet by 8 or 10 feet are preferred. Panels of this size can be conveniently used to construct floor-to-ceiling enclosures of the open-plan type, for example, and are easily handled by a single installer. In FIG. 1 of the drawing, wall panels 30 formed from the structure are shown being installed on a plasterboard wall 32. The panels are secured to the plasterboard surface by means of an adhesive 34 applied to the back of the panels as illustrated in FIG. 2. The panels may be held in position on the plasterboard by means of finishing nails driven into the panels. Clips, such as the clips 40, advantageously are secured to the margins of the panels to enable the sides of the panels to be positioned in snug, abutting relation to one another thereby giving the installation an integrated, unitary and highly attractive appearance.
While for purposes of illustration a respresentative embodiment of the structure of this invention has been illustrated and described, modifications and variations of said embodiment may become apparent to those skilled in the art upon reference to this disclosure and, accordingly, the scope of the invention is to be determined by the appended claims. | A tackable acoustical structure comprising a tack pin retaining layer, a sound absorptive layer, and a metal foil septum separating the tack pin retaining layer and the sound absorptive layer. The structure can be formed into wall panels having a flame spread index which qualifies them as a Class A rated building materials. | 1 |
This is a continuation of co-pending application Ser. No. 793,023 filed on Oct. 30, 1985, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to haze-free tin oxide coatings, and more particularly, to a method of making such coatings by interposing an improved undercoat film between the substrate and the tin oxide coating.
2. Description of the Invention
There is a demand for glass products, in particular, flat glass, having a tin oxide coating of high optical quality which modifies the radiation transmitting characteristics of the product but causes little or no diffusion of transmitted light. Any significant amount of light diffusion within a transmitted product is apparent as haze, which is detrimental in commercial use.
In the prior art it is recognized that the appearance of haze in tin oxide coatings formed on glass by exposure to tin compounds can be prevented or reduced by application of an intervening coating of suitably selected composition. For example, U.S. Pat. No. 2,617,741 proposes to provide a protective layer preceding the formation of the tin oxide coating by spraying the heated glass with a saturated or relatively concentrated aqueous solution of a suitable soluble metal salt, particularly the acetates of copper, aluminum, lead, zinc, iron, nickel, cobalt, thallium, silver or titanium.
Similarly, Terneu in U.S. Pat. No. 4,329,379, describes an undercoat of a metal oxide formed by decomposition of the acetylacetonate of titanium, nickel or zinc on which a tin oxide overcoat free from perceptible haze can be formed.
Gordon, in U.S. Pat. Nos. 4,187,336 (and 4,206,252) uses a tin oxide coating to provide a non-iridescence on glass structure which is described as being free of visible haze. In this structure, the haze which ordinarily would appear in the tin oxide coating is reduced by first depositing on the window glass an amorphous layer of SiO 2 , Si 3 N 4 , GeO 2 , Al 2 O 3 , or silicon oxy-nitride, or mixtures thereof with each other, or with other metal oxides. However, Gordon states that if this layer contains a large proportion of the metal oxides, Ga 2 O 3 , ZnO, In 2 O 3 , or SnO 2 , then haze formation is likely.
U.S. Pat. Nos. 4,547,400 and 4,548,836 describe the use of an undercoat of tin oxide formed from a chlorine-free organic/tin ion-containing compound on which a haze-free doped tin oxide layer can be formed.
The art also recognizes the advantage of using certain tin compounds such as monobutyltin trichloride as a precursor for the tin oxide coating. However, many of these tin compounds will produce hazy coatings unless formed under very restrictive and disadvantageous deposition conditions.
Accordingly, it is an object of this invention to provide an improved method of making haze-free tin oxide coatings.
Another object of this invention is to form a haze-free, tin oxide overcoat on glass from a precursor tin compound under a wide range of deposition conditions.
A specific object herein is to form a haze-free conductive tin oxide by using an improved undercoat film between the glass and the tin oxide coating.
A feature of the invention is the use of a haze-free tin oxide undercoat film on which haze-free tin oxide coatings may be formed.
A particular feature of the invention is the use of monophenyltin trichloride to form a haze-free tin oxide undercoat on glass, and, on which haze-free, conductive tin oxide coatings may be formed from tin compounds under process conditions which ordinarily would give hazy coatings if deposited directly on glass.
These and other objects and features of the invention will be made apparent from the following more particular description of the invention.
SUMMARY OF THE INVENTION
In accordance with the invention, there is provided herein an improved method of making haze-free tin oxide coatings on glass from an organotin source which usually forms hazy coatings except at restrictive and disadvantageous deposition conditions.
The method of the invention is characterized by providing a haze-free tin oxide undercoat film between the glass and the tin oxide coating whereupon the overcoat tin oxide coating assumes the haze-free characteristics of the undercoat film.
The undercoat tin oxide film in this invention preferably is prepared by chemical vapor deposition of monophenyltin trichloride, which provides a haze-free coating under a wide range of process conditions.
The overcoat haze-free tin oxide then may be deposited from tin compound which are known to form tin oxide coatings by vapor deposition. If desired, conductive tin oxide coating may be formed by including a dopant with the tin compound.
BRIEF DESCRIPTION OF THE DRAWING
In order to better understand the invention reference will be made to the accompanying drawing in which:
The FIGURE is a schematic diagram of an apparatus for carrying out the coating process of the invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the FIGURE, there is shown a diagrammatic representation of an apparatus suitable for carrying out the process of the present invention. Accordingly, a carrier gas 10, which includes oxygen, is metered through a feed line 11 at a predetermined flow rate through an air dryer tower 12 to provide a stream 13 of dry air. A separate air stream may be directed through a humidifier 14 containing a suitable quantity of water 15 to provide a wet air stream 16 at a desired relative humidity. Thereby an air stream 17, either dry or wet, may be passed through an evaporator 18 containing vessel 19 for holding liquid monophenyltin trichloride. The liquid is supplied to evaporator 18 by syringe pump 20 and syringe 21. The air stream is heated from an oil bath (not shown) to a desired vaporization temperature.
The vaporized liquid monophenyltin trichloride in the air stream 22 travels to a deposition chamber 23 having a coating nozzle 24 in which a glass substrate 25 is mounted on a plate 26 heated to a predetermined temperature. After deposition of the haze-free tin oxide undercoat on the glass substrate, the gaseous by-products of the deposition are exhausted.
To prepare the undercoat film from monophenyltin trichloride, the glass substrate suitably is held at a temperature of about 450° to 650° C., preferably 500° to 600° C.
The vaporization temperature of liquid monophenyltin trichloride in the process suitably ranges from about 100° to 400° C., preferably about 120° to 175° C.
The carrier gas is an oxygen-containing gas which suitably may be air, or a mixture of oxygen and an inert gas, and is preferably air.
The carrier gas may be dry or wet; preferably the water vapor concentration is less than 10 moles of water per mole of monophenyltin trichloride.
The carrier gas velocity suitably ranges from about 0.1 to about 10 m per sec.
The concentration of monophenyltin trichloride in the carrier gas suitably ranges from about 10 -5 to 10 -2 moles of monophenyltin trichloride per mole of carrier gas.
In general, the process of the invention produces a haze-free tin oxide undercoat which has less than 1% haze and greater than 80% visible transmission, and which is obtained in a desired thickness within a rapid deposition time.
The haze-free tin oxide coatings of the invention then are deposited on the haze-free undercoat film from organotin compounds which ordinarily will produce hazy coatings when deposited directly on glass at elevated glass temperatures. For example, such compounds as tin tetrachloride, monoalkyltin trichlorides, e.g. monobutyltin trichloride, dibutyltin diacetate, dimethyltin dichloride, and the like, may be used. Monobutyltin trichloride is a preferred source compound.
A dopant which imparts conductivity to the tin oxide overcoat may be included in the tin coating composition if desired. Such dopants include trifluoroacetic acid, trifluoroacetic anhydride, ethyl trifluoroacetate, pentafluoropropionic acid, difluorodichloromethane, monochlorodifluoromethane, 1,1-difluoroethanol, and the like.
A preferred conductive tin oxide overcoating composition is monobutyltin trichloride and trifluoroacetic acid, suitably in a composition range of about 70-99 wt. % of the organotin compound and 1-30 wt. % of the dopant.
The undercoat tin oxide film suitably has a thickness of at least 10 nm, preferably 30 nm. The tin oxide overcoating can have any desired thickness; usually for conductive coatings on glass it is about 150-250 nm.
The haze content of the tin oxide film and coatings herein are determined from Gardner hazemeter measurements on glass slides coated with tin oxide, according to ASTM D1003-61 (Reapproved 1977)-Method A.
The visible transmittance was measured on a UV/vis spectrophotometer over the 400-800 nm region, versus air, and the % T vis was averaged over the wavelengths.
The film thickness was measured by the beta-backscatter method according to British Standards Institution method BS5411: Part 12, 1981, ISO 3543-1981.
The advantages of the invention can be more readily appreciated by reference to the following specific examples in which a tin oxide overcoat is formed on glass which has been provided with an undercoat film obtained from monophenyltin trichloride (Table I); and of conductive tin oxide coatings which have been provided with an undercoat film from monophenyltin trichloride over a range of process conditions (Table II).
TABLE I__________________________________________________________________________Haze-Content of Tin Oxide Structures on GlassObtained Using a Tin Oxide Undercoat from Monophenyltin Trichloride(MPTC) and a Tin Oxide Overcoat from Monobutyltin Trichloride (MBTC) % Haze Undercoat LayerConc. Substrate Film Directly on UncoatedExamplemoles/ltr. Temp. (°C.) (MPTC) Glass (MBTC) Glass__________________________________________________________________________1 0.079 600 0.90 5.52 " 550 0.75 2.73 " 500 0.75 1.1 0.75__________________________________________________________________________
TABLE II__________________________________________________________________________Haze-Content of Conductive Tin Oxide Coatings on GlassObtained Using a Tin Oxide Undercoat from MPTC and a Conductive TinOxideOvercoat from MBTC Under Different Process Conditions % Haze Conductive Undercoat LayerConc. Substrate Film Directly on UncoatedExamplemoles/ltr. Temp. (°C.) (MPTC) Glass (MBTC) Glass__________________________________________________________________________4 0.119 600 0.90 5.45 " 550 0.75 2.66 " 500 0.75 1.17 0.159 600 0.75 5.28 " 500 0.75 1.0 0.75__________________________________________________________________________ Dew point, Exs. 1-3, 2.4; Exs. 4-8, 12.0; vaporization temp., Exs. 1-8, 157° C.; thickness of MPTC coatings, Exs. 1-8, 30 nm; MBTC, 190 nm deposition times, Exs. 1-8, MPTC 6-22 seconds, Exs. 1-3, MBTC, 7-9 seconds; visible transmittance, Exs. 1-8, MPTC, 80%; Exs. 1-3, MBTC, 75%;
The tin oxide coatings obtained using monophenyltin trichloride as an undercoat are haze free under a wide range of process conditions, and at certain substrate temperatures show a value substantially equal to that of uncoated glass. On the other hand, tin oxide coatings made from monobutyltin trichloride directly on glass are hazy under all process conditions.
The reason that haze-free tin oxide coatings can be produced using haze-free monophenyltin trichloride as an undercoat is not well understood at present. However, this effect may be related to the minimum of surface voids, or pitting, observed in undercoat tin oxide film made from this compound.
While the invention has been described with reference to particular embodiments thereof, it will be understood that changes and modifications may be made which are within the skill of the art. It is intended to be bound only by the claims which follow hereinafter. | Haze-free tin oxide coatings are made from an organotin compound which ordinarily gives only hazy coatings. The improvement comprises first forming an undercoat of a haze-free tin oxide film on a substrate, preferably by decomposition of monophenyltin trichloride. Thereafter the tin oxide overcoating assumes the haze-free characteristics of the undercoat film. | 2 |
FIELD OF THE INVENTION
[0001] The present invention relates, by way of novel industrial products, to 4-cyano-4′-hydroxybenzophenone derivatives of formula I below, which are benzophenone α-D-glycopyranosides. It further relates to the process for their preparation and to their use in therapeutics, especially in the form of compositions in which they are present as active principles.
PRIOR ART
[0002] EP-A-0051023 has disclosed compounds which contain a hydroxybenzo-phenone residue substituted by a β-D-xylosyl group and which have valuable pharmacological activity for the treatment or prevention of venous thrombosis.
[0003] Also, EP-A-0133103 has disclosed derivatives of the benzylphenyl β-D-xyloside type which possess hypocholesterolemic and hypolipidemic properties. It is also known that derivatives in which the β-D-xylosyl radical has been replaced with a β-D-thioxylosyl radical have been described in EP-A-0365397 and EP-A-0290321, said compounds being useful on account of their antithrombotic activity.
[0004] Finally, the article by F. BELLAMY et al., J. Med. Chem., 1993, 36 (no. 7), pages 898-903, has disclosed compounds derived from benzophenone substituted by glycosyl groups, among which only the derivatives of the β configuration have antithrombotic activity. A study of these products demonstrated that these compounds, particularly those containing a β-D-xylosyl group, were good substrates for galactosyltransferase I and, consequently, were capable of initiating the synthesis of glycosaminoglycans (GAGs). This mode of action, obtained after oral administration of the product, is very probably responsible for the antithrombotic activity, and only those derivatives in which the D-xylose is of the β configuration exhibit activity in this therapeutic field. There is therefore a correlation between the action on GAG synthesis and the antithrombotic activity which meant that the compounds other than those derived from β-D-xylose were of no value in this therapeutic field.
OBJECT OF THE INVENTION
[0005] According to the invention, it is proposed to provide a novel technical solution for obtaining novel products of therapeutic value in respect of arterial atheromatous plaque, either for treating said plaque or for preventing its appearance.
SUBJECT OF THE INVENTION
[0006] According to the novel technical solution of the invention, [4-(4-cyanobenzoyl)phenyl]α-D-glycopyranoside compounds are used which, surprisingly, in the light of the publications cited above, exhibit activity in the prevention or regression of arterial atheromatous plaque.
[0007] The novel products according to the invention are selected from the group consisting of:
[0008] (i) the [4-(4-cyanobenzoyl)phenyl]α-D-glycopyranosides of formula I:
[0009] in which the α-D-glycopyranosyl group R is an α-D-glucopyranosyl, α-D-galactopyranosyl, α-D-mannopyranosyl, α-D-arabinopyranosyl, α-D-lyxopyranosyl or α-D-ribopyranosyl group; and
[0010] (ii) their esters resulting from the esterification of at least one OH group on each glycopyranosyl group by a C 2 -C 4 alkanoic or cycloalkanoic acid.
[0011] According to a second feature of the invention, a process is proposed for the preparation of the compounds of formula I above and their esters.
[0012] According to yet a third feature of the invention, a therapeutic composition is provided which contains, in association with a physiologically acceptable excipient, a therapeutically effective amount of at least one compound of formula I or one of its esters.
[0013] According to another feature of the invention, it is also recommended to use a compound of formula I or one of its esters as an active principle for the preparation of a drug to be used in therapeutics for combating atheromatous plaque, particularly for its prevention or treatment.
DETAILED DESCRIPTION
[0014] The novel compounds according to the invention comprise the products of formula I and their esters; they are pyranoside derivatives of 4-cyano-4′-hydroxy-benzophenone [or 4-(4-hydroxybenzoyl)benzonitrile]. The preferred products, in which the glycoside radical is in the pyranose form, have the formulae below, which are given according to the structure of the glycopyranosyl group R of the α-D configuration:
[0015] In these formulae, R 1 is a hydrogen atom or a group COR 2 , R 2 being a C 1 -C 3 alkyl group selected from methyl, ethyl, propyl, isopropyl and cyclopropyl groups.
[0016] The process for the preparation of a compound of formula I or one of its esters according to the invention comprises:
[0017] (1°) reacting a peracetylated pentose or hexose of the pyranosyl structure of formula II:
[0018] in which Z is H or CH 2 OAc,
[0019] selected from the group consisting of 1,2,3,4,6-pentaacetyl-D-glucose, 1,2,3,4,6-pentaacetyl-D-galactose, 1,2,3,4,6-pentaacetyl-D-mannose, 1,2,3,4-tetraacetyl-D-arabinose, 1,2,3,4-tetraacetyl-D-lyxose and 1,2,3,4-tetraacetyl-D-ribose,
[0020] with 4-(4-hydroxybenzoyl)benzonitrile of formula III:
[0021] to give, after purification, the corresponding oside compound of formula IV:
[0022] in which Z is defined as indicated above; and
[0023] (2°) if necessary, carrying out a displacement reaction on the acetyl groups of the resulting oside compound of formula IV in order to replace them with hydrogen atoms to give the corresponding compound of formula I in which R 1 is H, it being possible for the other esters (in which R 1 is other than Ac) to be obtained by esterifying the compound of formula I in which R 1 is H with a C 3 -C 4 acid.
[0024] Advantageously, the reaction II+III of step (1°) is carried out in an organic solvent (especially dichloromethane), in the presence of a Lewis acid (for example tin tetrachloride), at a temperature between 25° C. and the boiling point of the solvent, for 10 to 30 hours.
[0025] In step (2°), the replacement of the Ac groups with hydrogen atoms is advantageously performed as follows. The compound of formula IV is reacted with NH 3 in solution in an anhydrous alcohol (especially methanol) in order to displace the Ac groups and replace them with H.
[0026] In a variant, the reaction II+III→IV of step (1°) can be replaced with the reaction V+III→IV, where V is a corresponding peracetylated halogenopentose or halogenohexose. Under these circumstances, step (1°) becomes step (1′) below, namely:
[0027] (1′) reacting a peracetylated halogenopentose or halogenohexose of the pyranosyl structure of formula V:
[0028] in which X is a halogen atom (i.e. F, Cl, Br or I, the preferred halogen atom being Br) and Z is H or CH 2 OAc,
[0029] selected from the group consisting of 1-bromo-2,3,4,6-tetraacetyl-D-glucose, 1-bromo-2,3,4,6-tetraacetyl-D-galactose, 1-bromo-2,3,4,6-tetraacetyl-D-mannose, 1-bromo-2,3,4-triacetyl-D-arabinose, 1-bromo-2,3,4-triacetyl-D-lyxose and 1-bromo-2,3,4-triacetyl-D-ribose,
[0030] with 4-(4-hydroxybenzoyl)benzonitrile of formula III:
[0031] to give, after purification, the corresponding oside compound of formula IV:
[0032] in which Z is defined as indicated above.
[0033] Advantageously, the reaction V+III→IV is carried out in an anhydrous solvent such as dichloromethane, 1,2-dichloroethane or acetonitrile, in the presence of a coupling agent such as silver trifluoromethanesulfonate or silver oxide, at a temperature of the order of −10 to +10° C., for 5 to 40 hours.
[0034] The reactions II+III→IV and V+III→IV are applicable to the preparation of all the compounds of formula IV according to the invention.
[0035] Other advantages and characteristics of the invention will be understood more clearly from the following Preparatory Examples and pharmacological tests. Of course, these details as a whole do not imply a limitation but are provided by way of illustration.
EXAMPLE I (FORMULA I A , R 1 =COCH 3 )
[0036] [4-(4-Cyanobenzoyl)phenyl]2,3,4,6-tetra-O-acetyl-α-D-glucopyranoside
[0037] A suspension of 12.17 g (31.10 −3 mol) of 1,2,3,4,6-penta-O-acetyl-β-D-glucose and 10.36 g (46.10 −3 mol) of 4-(4-hydroxybenzoyl)benzonitrile in 500 ml of dichloromethane is prepared and 8.5 ml (72.6.10 −3 mol) of anhydrous tin tetrachloride are added gradually at 0° C., with stirring. After stirring for 20 hours at room temperature, a further 4.25 ml (36.3.10 −3 mol) of anhydrous tin tetrachloride are added and the reaction mixture is refluxed gently for 24 hours. After cooling, the reaction medium is poured onto ice. The organic phase is separated off, then washed with water, extracted with 1 N sodium hydroxide solution, then washed with water until the washings are neutral, and dried over magnesium sulfate. After concentration under reduced pressure, the residue is purified by chromatography on silica gel using a toluene/ethyl acetate mixture (8/2; v/v) as the eluent to give 918 mg of the expected product in the form of an amorphous white solid (yield=5.3%).
[0038] M.p.=63° C.
[0039] [α] D 29 =+83.2° (c=0.25; DMSO)
EXAMPLE 2 (FORMULA I A , R 1 =H)
[0040] [4-(4-Cyanobenzoyl)phenyl]α-D-glucopyranoside
[0041] A solution of 575 mg (1.06.10 −3 mol) of the compound obtained according to Example 1 in 50 ml of methanol is prepared and 5.6 ml of a saturated solution of ammonia in methanol are added at 0° C., with stirring. The reaction mixture is subsequently stirred for 6 hours at room temperature and the solvent is then driven off under reduced pressure. The crude product obtained is purified by chromatography on silica gel using a dichloromethane/methanol mixture (9/1; v/v) as the eluent to give 137 mg of the expected product in the form of a fine white solid (yield=34%).
[0042] M.p.=130° C.
[0043] [α] D 23 =+145° (c=0.33; DMSO)
EXAMPLE 3 (FORMULA I C , R 1 =COCH 3 )
[0044] [4-(4-Cyanobenzoyl)phenyl]2,3,4,6-tetra-O-acetyl-α-D-mannopyranoside
[0045] A solution of 9.9 g (144.10 −3 mol) of 4-(4-hydroxybenzoyl)benzonitrile and 26 g (63.10 −3 mol) of 2,3,4,6-tetra-O-acetyl-α-D-mannopyranosyl bromide in 300 ml of 1,2-dichloroethane is prepared in the presence of about 4 g of a molecular sieve. The mixture is cooled to −20° C. and 34 g (132.10 −3 mol) of silver trifluoromethanesulfonate are added at this temperature. The reaction mixture is stirred for 24 hours at 0° C. and then filtered to remove the solid particles. The organic phase is washed with dilute hydrochloric acid solution, then with water, then with dilute sodium hydroxide solution and finally with water. After drying over magnesium sulfate, the solution is concentrated under reduced pressure and the crude product obtained is purified by chromatography on silica gel using a toluene/ethyl acetate mixture as the eluent to give 19 g of the expected product in the form of a pale yellow solid (yield=77%).
[0046] M.p.=60° C.
[0047] [α] D 27 =+64° (c=0.62; DMSO)
EXAMPLE 4 (FORMULA I C , R 1 =H)
[0048] [4-(4-Cyanobenzoyl)phenyl]α-D-mannopyranoside
[0049] 16.7 g (30.10 −3 mol) of the product obtained according to Example 3 are dissolved in 50 ml of methanol, and 100 ml of a saturated solution of ammonia in methanol are added at 0° C. The reaction mixture is stirred for 6 hours at 0-10° C. and then concentrated under reduced pressure. The crude product is purified by chromatography on silica gel using a dichloromethane/methanol mixture (15/1; v/v) as the eluent. The pure product fraction is crystallized from acetone to give 7.9 g of the expected product in the form of fine light beige crystals (yield=68%).
[0050] M.p.=145° C.
[0051] [α] D 27 =+102° (c=0.17; DMSO)
EXAMPLE 5 (FORMULA I B , R 1 =COCH 3 )
[0052] [4-(4-Cyanobenzoyl)phenyl]2,3,4,6-tetra-O-acetyl-α-D-galactopyranoside
[0053] The expected product is obtained in the form of an amorphous solid with a yield of 4% by following a procedure analogous to Example 1 and starting from 1,2,3,4,6-penta-O-acetyl-D-galactose.
[0054] M.p.=64-66° C.
[0055] [α] D 29 =+156° (c=0.26; DMSO)
EXAMPLE 6 (FORMULA I B , R 1 =H)
[0056] [4-(4-Cyanobenzoyl)phenyl]α-D-galactopyranoside
[0057] The expected product is obtained in the form of a white solid with a yield of 90% by following a procedure analogous to Example 2 and starting from the compound obtained according to Example 5.
[0058] M.p.=240° C.
[0059] [α] D 29 =+173° (c=0.25; DMSO)
EXAMPLE 7 (FORMULA I D , R 1 =COCH 3 )
[0060] [4-(4-Cyanobenzoyl)phenyl]2,3,4-tri-O-acetyl-α-D-arabinopyranoside
[0061] The expected product is obtained in the form of a yellow oil with a yield of 15% by following a procedure analogous to Example 3 and starting from 2,3,4-tri-O-acetyl-D-arabinopyranosyl bromide.
[0062] [α] D 24 =−10.7° (c=0.38; CH 2 Cl 2 )
EXAMPLE 8 (FORMULA I D , R 1 =H)
[0063] [4-(4-Cyanobenzoyl)phenyl]α-D-arabinopyranoside
[0064] The expected product is obtained in the form of a fine beige solid with a yield of 75% by following a procedure analogous to Example 4 and starting from the compound obtained according to Example 7.
[0065] M.p.=160° C.
[0066] [α] D 26 =−66° (c=0.32; DMSO)
EXAMPLE 9 (FORMULA I E , R 1 =COCH 3 )
[0067] [4-(4-Cyanobenzoyl)phenyl]2,3,4tri-O-acetyl-α-D-lyxopyranoside
[0068] The expected product is obtained in the form of an oil with a yield of 60% by following a procedure analogous to Example 1 and starting from 1,2,3,4-tetra-O-acetyl-D-lyxopyranose.
[0069] [α] D 24 =+40.3° (c=0.67; CH 2 Cl 2 )
EXAMPLE 10 (FORMULA I E , R 1 =H)
[0070] [4-(4-Cyanobenzoyl)phenyl]α-D-lyxopyranoside
[0071] The expected product is obtained in the form of a white solid with a yield of 90% by following a procedure analogous to Example 2 and starting from the compound obtained according to Example 9.
[0072] M.p.=173° C.
[0073] [α] D 28 =+125° (c=0.175; DMSO)
EXAMPLE 11 (FORMULA I F , R 1 =H)
[0074] [4-(4-Cyanobenzoyl)phenyl]α-D-ribopyranoside
[0075] [4-(4-Cyanobenzoyl)phenyl]2,3,4-tri-O-acetyl-α-D-ribopyranoside is obtained in the form of a yellow solid by following a procedure analogous to Example 1 and starting from 1,2,3,4-tetra-O-acetylribopyranose. It is treated with a solution of ammonia in methanol according to the protocol described in Example 2 to give the expected product in the form of a white powder with an overall yield of 6%.
[0076] M.p.=164° C.
[0077] [α] D 26 =+77.7° (c=0.21; DMSO)
[0078] The antiatheromatous activity of the compounds according to the invention was evaluated as a function of their ability to lower the serum cholesterol level in mice subjected to a fatty diet. Several publications have in fact demonstrated a close correlation between an excess of lipids and a marked increase in the risk of atheroma (cf. Lancet 1996, 348, pages 1339-1342; Lancet 1990, 335, pages 1233-1235). This correlation affords a test which is more rapid than direct experiments on the atheromatous plaque, which require a lengthy treatment of the animals and an expensive histological study of the walls of the aortic arch.
[0079] The test used consists in administering a single dose of the compound to female mice of the C57BL/6J strain. The protocol is as follows: On the first day (D0), the mice are fasted from 9 am to 5 pm, a blood sample being taken at 2 pm. At 5 pm, a given amount of food (a fatty diet comprising 1.25% of cholesterol and 0.5% of cholic acid) is distributed. On the second day (D1), the food leftovers are weighed at 9 am and the mice are fasted from 9 am to 2 pm. A blood sample is taken at 2 pm. For the treated groups of mice, the compound is administered at 9 am on the second day (D1) by tubage in the form of a suspension in a 3% aqueous solution of gum. The control groups receive only the aqueous gum.
[0080] The compounds were tested at a dose of 100 mg/kg. The total serum cholesterol is assayed and the results are expressed as the percentage inhibition of the increase in cholesterolemia compared with the control group. The results obtained are given in the “Activity” column of Table I. It may furthermore be noted that analysis of the cholesterol content of the different classes of serum lipoproteins shows a favorable effect of the product on the ratio HDL cholesterol/total cholesterol.
[0081] It was also demonstrated that the compounds of formula I according to the invention do not induce GAG synthesis.
[0082] The products of formula I and their esters according to the invention can preferably be administered orally in the form of tablets or gelatin capsules each containing 20 to 500 mg of a compound of formula I or one of its esters as the active principle, in association with excipients. The dosage will be about 1 to 4 units per day. The products according to the invention are advantageously prescribed for atheromatous plaque and particularly for preventing or treating the risk of atheroma.
TABLE 1 Ex. R R 1 Activity (%) 1 α-D-Glc COCH 3 −27 2 α-D-Glc H −23 3 α-D-Man COCH 3 −10 4 α-D-Man H −38 5 α-D-Gala COCH 3 −32 6 α-D-Gala H −35 7 α-D-Ara COCH 3 −25 8 α-D-Ara H −29 9 α-D-Lyx COCH 3 — 10 α-D-Lyx H −48 11 α-D-Rib H −26 | The invention concerns (i) [4-(4-cyanobenzyl)phenyl]α-D-glycopyranosides of formula (I) wherein: the group α-D-glycopyranosyl R represents a α-D-glycopyranosyl, α-D-galactopyranosyl. α-D-mannopyranosyl, α-D-arabinopyranosyl, α-D-lyxopyranosyl, or α-D-ribopyranosyl group: (ii) their esters resulting from the esterification of at least a OH function of each pyranosyl group with a C 2 -C 4 alkanoic or a cycloalkanoic acid, as novel industrial products. Said novel [4-(4-cyanobenzyl)phenyl]α-D-glycopyranosides are useful in therapy for fighting against atheromatous plaque. | 2 |
RELATED APPLICATIONS
This application is a continuation-in-part of applications Ser. No. 08/663,516, filed Jun. 13, 1996, Ser. No. 60/024,610, filed Aug. 26, 1996, and Ser. No. 08/701,855, filed Sep. 4, 1996; all of which are incorporated herein in their entireties.
TECHNICAL FIELD OF THE INVENTION
The present invention relates generally to cutting elements for use in earth-boring drill bits and, more specifically, to a means for increasing the life of cutting elements that comprise a layer of superhard material, such as diamond, affixed to a substrate. Still more particularly, the present invention relates to a polycrystalline diamond compact comprising a supporting substrate and a diamond layer supported thereon, wherein the supporting substrate includes a plurality of projections having defined frequencies, amplitudes and/or configurations.
In a typical drilling operation, a drill bit is rotated while being advanced into a soil or rock formation. The formation is cut by cutting elements on the drill bit, and these cuttings are flushed from the borehole by the circulation of drilling fluid toward the top of the borehole. The drilling fluid is delivered to the drill bit through a passage in the drill stem and is ejected outwardly through nozzles in the cutting face of the drill bit. The ejected drilling fluid is directed outwardly through the nozzles at high speed to aid in cutting, and to flush the cuttings and cool the cutter elements.
Conventional cutting elements typically comprise a stud or cylinder having a supporting surface at one end, and a cutting disk mounted on the supporting surface. The disk comprises a substrate having one surface bonded to the supporting surface and a second surface that carries a diamond substance such as a layer of polycrystalline diamond or thermally stable diamond. The stud and substrate are normally formed of a hard material such as tungsten carbide (WC). Alternatively, the diamond layer can be directly applied to the carbide stud or cylinder. The techniques for constructing polycrystalline diamond (PDC) cutting elements are generally well known will not be described in detail. They can be summarized as follows: a carbide substrate is formed having a desired surface configuration on each of its first and second surfaces; the substrate is placed in a mold with a superhard material, such as diamond powder, and subjected to high temperature, high pressure pressing, resulting in the formation of a diamond layer bonded to the substrate surface; and the substrate is braze-bonded to the stud or cylinder. At present, the interface between the superhard cutting layer and the substrate is typically planar, although some non-planar diamond/substrate interfaces have been disclosed.
As used herein, the term "superhard" means a material having a hardness of at least 2,700 Knoop (kg/mm2). PCD grades typically have a hardness range of about 5,000-8,000 Knoop (kg/mm2) while PCBN grades typically have hardnesses that fall within the range of about 2,700-3,500 Knoop (kg/mm2). By way of comparison, the hardest commonly used grade of cemented tungsten carbide has a hardness of about 1475 Knoop (kg/mm2).
Although cutting elements having this configuration have significantly expanded the scope of formations for which drilling with diamond bits is economically viable, the interface between the substrate and the diamond layer continues to be a limiting factor, as it is prone to failure, resulting in delamination, spalling and/or chipping of the diamond layer. There are several possible explanations for the failure of this interface. One explanation is that the interface between the diamond and the substrate is subject to high residual stresses resulting from the manufacturing processes of the cutting element. Specifically, because manufacturing occurs at elevated temperatures and pressures, the different properties of the diamond and substrate material, including their differing coefficients of thermal expansion result in thermally-induced stresses. In addition, finite element analysis (FEA) has demonstrated that during cutting high stresses are localized in both the outer diamond layer and at the tungsten carbide interface. Finally, the cutting elements are subjected to extremes of temperature and heavy loads when the drill bit is in use. It has been found that during drilling, shock waves may rebound from the internal planar interface between the two layers and interact destructively. All of these phenomena are deleterious to the life of the cutting element during drilling operations, as the stresses, when augmented by stresses attributable to the loading of the cutting element by the formation, may cause spalling, fracture and even delamination of the diamond layer from the substrate. In addition to the foregoing, state of the art cutting elements often lack sufficient diamond volume to cut highly abrasive formations, as the thickness of the diamond layer is limited by the resulting high residual stresses and the difficulty of bonding a relatively thick diamond layer to a planar substrate.
Hence, it is desired to provide a new and improved preform cutting element that overcomes or reduces the spalling and delamination problems referred to above.
SUMMARY OF THE INVENTION
The present invention provides a supporting substrate for a PDC compact wherein the substrate is provided with an irregular or asymmetric amplitude and/or frequency modulated surface to which the abrasive layer is affixed. The substrate surface may comprise various irregular features, including but not limited to irregular undulations, rings, spirals, or protrusions having various other shapes and/or combinations of shapes. The surface features may vary in height (amplitude), displacement (wavelength) or both. In one embodiment, the amplitude and/or wavelength vary according to defined mathematical equations.
One embodiment of the present invention comprises an asymmetrical substrate surface in which irregular undulations increase in height and/or displacement adjacent one side of the surface and decrease in height and/or spacing adjacent the opposite side of the surface. This produces a dual purpose substrate, whose orientation can be adjusted to maximize performance.
Another embodiment of the present invention comprises a substrate having a substantially planar interface from which a plurality of protuberances extend into the diamond table. The preferred protuberances decrease in amplitude toward the center of the interface and this decrease according to a prescribed mathematical relationship.
BRIEF DESCRIPTION OF THE DRAWINGS
For an introduction to the detailed description of the preferred embodiments of the invention, reference will now be made to the accompanying drawings, wherein:
FIG. 1 is a side elevation of a cutting element according to the present invention;
FIGS. 2A and 2B are cross-sectional and perspective views, respectively, of a first embodiment of the present substrate layer;
FIGS. 3A and 3B are cross-sectional and perspective views, respectively, of a second embodiment of the present substrate layer;
FIGS. 4A and 4B are cross-sectional and perspective views, respectively, of a third embodiment of the present substrate layer;
FIGS. 5A and 5B are cross-sectional and perspective views, respectively, of a fourth embodiment of the present substrate layer;
FIGS. 6A and 6B are cross-sectional and perspective views, respectively, of a fifth embodiment of the present substrate layer;
FIGS. 7A and 7B are cross-sectional and perspective views, respectively, of a sixth embodiment of the present substrate layer;
FIGS. 8, 9 and 10 are cross-sectional views of alternative embodiments of the surface devices of the present invention;
FIGS. 11A and 11B are cross-sectional and perspective views, respectively, of a seventh embodiment of the present substrate layer;
FIGS. 12A and 12B are cross-sectional and perspective views, respectively, of an eighth embodiment of the present substrate layer;
FIGS. 13A and 13B are cross-sectional and perspective views, respectively, of a ninth embodiment of the present substrate layer;
FIGS. 14A and 14B are cross-sectional and perspective views, respectively, of a tenth embodiment of the present substrate layer;
FIGS. 15A and 15B are cross-sectional and perspective views, respectively, of a eleventh embodiment of the present substrate layer;
FIGS. 16A and 16B are cross-sectional and perspective views, respectively, of a twelfth embodiment of the present substrate layer; and
FIGS. 17A and 17B are cross-sectional and perspective views, respectively, of a thirteenth embodiment of the present substrate layer;
FIG. 18 is a cross-sectional view of a fourteenth embodiment of the present substrate layer; and
FIG. 19 is a cross-sectional view of a fifteenth embodiment of the present substrate layer.
DETAILED DESCRIPTION OF THE INVENTION
Referring initially to FIG. 1A, a cutting element 10 in accordance with the present invention comprises a stud 12 and a disc-shaped cutting compact 14 bonded thereto. As is known in the art, cutting compact 14 comprises a diamond layer 16 affixed to the surface 17 of supporting substrate 18. The present invention is directed to providing an improved stress distribution between substrate 18 and diamond layer 16, which enhances performance. Alternatively, cutting element could comprise a cylinder 13 with the cutting compact affixed perpendicularly to the axis of the cylinder, as shown in FIG. 1B, or the diamond compact could be affixed directly to the stud, as shown in FIGS. 1C and D. In any event, the present invention is directed to providing an improved bond between the diamond compact and the surface on which it is mounted. Thus, while the invention is described hereinafter in terms of the surface 17 of a supporting substrate 18, it will be understood that it is equally applicable to all of the configurations shown in FIGS. 1A-D, as well as to other applications in which diamond compacts and inserts are used.
Referring now to FIGS. 2A and 2B, one embodiment of the present substrate 20 includes a plurality of undulations 22 extending across the face of the substrate and defining a plurality of ridges 23 and valleys 24. A centerline 26 (shown in phantom) is defined as passing through the center point of each successive ridge face, with the center point being equidistant from the peak and nadir of that face. The height h of a given ridge 23 is defined as the shortest distance from the peak of that ridge to the centerline 26. The depth d of a given valley 24 is defined as the distance from the nadir of that valley to the centerline 26. The amplitude a of a given ridge/valley combination is defined as the height of a given ridge plus the depth of an adjacent valley. The wavelength w of a given ridge/valley combination is defined as the lateral distance from the peak of a given ridge to the peak of an adjacent ridge.
In accordance with the principles of the present invention, the surface of substrate 20 is configured such that at least one of either the amplitude a or the wavelength w is non-constant across the face of substrate 20. More specifically, the amplitude may be increasing while the wavelength is constant or increasing, or the amplitude may be decreasing while the wavelength is constant or increasing. It will be understood that no particular orientation of the substrate surface is specified, as the principles of the present invention describe relative magnitudes. Thus, undulations that appear to be "increasing" as drawn may be described as "decreasing" when viewed from another perspective, and vice versa.
According to the embodiment shown in FIGS. 3A and 3B, the amplitude and wavelength of the undulations are both greatest at the same side of the substrate. In this manner, an asymmetric substrate is formed, having large undulations at one edge, which taper off to much smaller undulations, if any, at the opposite edge. It is believed that the asymmetric compact formed using such an asymmetric substrate will be advantageous, in that it is capable of providing a dual purpose cutting surface in a single insert. Thus, the insert can be oriented to provide the optimal balance of abrasion resistance and impact resistance, depending on the application for which it is to be used.
Alternatively, the present invention also includes substrate surfaces wherein the relationship of adjacent pairs of ridges varies or is irregular, rather than constant. That is, as shown in FIGS. 4A and 4B, the amplitude and wavelength of the undulations 22 can vary simultaneously, independently and without pattern. It will be further understood that the undulations 22 described above can be oriented so as to lie either across the cutting path or parallel to it without departing from the spirit of the present invention. Likewise, the average amplitude of the undulations can be largest in one portion of the substrate surface, while the average wavelength of the undulations is largest in another portion of the substrate surface. In addition, while the undulations shown in FIGS. 4A and 4B are substantially straight, it will be understood that the principles of the present invention could be carried out using crooked or wavy undulations.
Still another alternative embodiment of the present invention is shown in FIGS. 5A and 5B, wherein a single ridge 52 and valley 54 define a spiral 53 in which the amplitude of ridge 52 and 52 valley 54 is greatest at the perimeter of the substrate and decreases as the radius of the ridge decreases. Alternatively, as shown in FIGS. 6A and 6B, the amplitude of ridge 62 and valley 64 can be smallest adjacent the perimeter of the substrate and increase toward the center.
Still another embodiment of the present invention, shown in FIGS. 7A and 7B, encompasses a substrate 70 having a contoured surface 71 that includes a plurality of variously sized projections 72 and indentations 74. These serve the same purpose as undulations 22 and valleys 24, namely a reduction in stress concentration and corresponding increase in the ability of the diamond layer to remain affixed to the substrate. It is preferred that projections 72 and indentations 74 vary in height and diameter, including either regular or irregular variations in at least one of these parameters.
In the embodiments described above, undulations 22 are depicted as generally sinusoidal. The principles of the present invention can also be applied to substrate configurations wherein the surface projections have other shapes. Some alternative shapes are shown in FIGS. 8 and 9, although the alternative shapes depicted therein are not intended to be an exhaustive list of possible alternatives. FIG. 8 shows a pair of ridges 82 and an intervening valley 84, in which the ridges 82 and the valley 84 each include a single inflection or shoulder 86. As used herein, the term shoulder means an inflection at which the absolute value of the slope of the line defining the face decreases and then increases again. FIG. 9 shows a pair of ridges 92 and an intervening valley 94, in which the ridges 92 and the valley 94 each include a pair of inflections or shoulders 96. The waveforms shown in FIGS. 8 and 9, as well as variations thereof, can behave either constant or varying amplitudes and/or frequencies.
As shown in FIG. 10, each ridge 101 may include more than one maximum 102 and each valley 103 may include more than one minimum 104. For ease of reference hereinafter, maxima 103 and minima 104 are referred to as points of zero slope. In addition, the foregoing waveforms can be combined or superimposed in a variety of ways.
In still another embodiment, the surface of the substrate may include some combination of the foregoing devices. By way of example only, FIGS. 11A and 11B show a surface comprising a ring 110 surrounding a plurality of undulations 122. It will be understood that the reverse is also applicable, in that the surface can include one or more undulations surrounding one or more rings or other devices. It will further be understood that undulations 122, and any other surface device described herein, need not be straight or linear, but may be curvilinear or wavy, or have any other desired configuration.
Likewise, as shown in FIGS. 12A and 12B, either the substrate itself or the centerline of the features can define a convex or concave shape. If the substrate surface is convex (domed), the diamond layer may be thickest around the perimeter of the compact, while if the substrate surface is concave (bowl-shaped), the diamond layer will be thickest at the center of the compact. It will be understood that neither the concave nor the convex embodiment need be symmetrical, i.e. the center of the dome or hollow can be elsewhere than at the center of the substrate surface.
In still another embodiment, shown in FIGS. 13A and 13B, the surface can be divided into a plurality of sectors 130, 132 in which the average amplitude of the surface features decreases in opposite directions. Alternatively or in addition, the frequency and/or amplitude of the features can vary from sector to sector. Furthermore, features that are shown decreasing could increase and features shown to be increasing could decrease in the same manner.
Referring now to FIGS. 14A and 14B, another embodiment of the present invention has one or more surface features 140 that each describe a closed loop 142 on the surface. The closed loops 142 can be nested and generally circular, as shown, or not. As best shown in FIG. 14A, surface features 140 comprise undulations that comprise both ridges 144 and valleys 146, to which any of the variations described above apply, including, but not limited to, variations in amplitude, variations in wavelength, and the addition of shoulders.
In the alternative, the surface may include either ridges or valleys. These embodiments, shown in FIGS. 15A-B and 16A-B, are referred to hereinafter as "ridged" and "grooved" surfaces respectively. In each case, approximately one-half of the waveform is eliminated, leaving only ridges 150 extending into the diamond layer (FIGS. 15A and 15B) or grooves 160 extending into the substrate layer (FIGS. 16A and 16B). Between the ridges or grooves are relatively flat intervening areas 152, 162. By "relatively flat" it is meant that the amplitude of any surface modulation in intervening areas 152, 162 is significantly less than the amplitude of ridges 150 or grooves 160. For example, intervening areas 152 and 162 can be slightly convex, flat, slightly concave or wavy. As discussed above with respect to earlier embodiments, the amplitude of ridges 150 and grooves 160 can vary randomly across the surface, increase generally toward the center of the surface (as shown in FIGS. 15A and 15B), or decrease generally toward the center of the surface (as shown in FIGS. 16A and 16B). Likewise ridges 172 and grooves 174 can both be used on a single substrate, as shown in FIGS. 17A and 17B.
According to another embodiment, the substrate/diamond interface described above includes protuberances whose amplitudes and position relative to the center of the interface, or displacement, are governed by defined mathematical relationships. These mathematical relationships can apply over the entire substrate interface or over a portion of the interface defined within a restricted region. For example, the amplitudes of the protuberances can be governed by defined mathematical relationships so that they vary consistently and predictably. An example of an equation that can be used to define the amplitudes of the protuberances is
A.sub.i =K.sub.a r.sub.i.sup.n A.sub.0
where A 0 is the amplitude at the commencement of the pattern, A i is the amplitude at a distance r i from the position of A 0 , n is a real number, and K a is a relational constant for the amplitude function. In this equation, the position of A 0 corresponds to r 0 .
Alternatively, the displacement of each protuberance or feature can be governed by defined mathematical relationships such that:
D.sub.i =K.sub.d r.sub.i.sup.m D.sub.0
where D 0 is the displacement at the commencement of the pattern, D i is the displacement at a distance r i from the position of D 0 , m is a real number, and K d is a relational constant for the displacement function. In this equation, the position of D 0 corresponds to r 0 .
If the foregoing mathematical equations are applied over less than all of the surface of the interface, the balance of the surface can be planar or irregular. The portion of the surface that is defined by the foregoing equations is preferably dependent on the type of protuberance and mathematical relationships describing the amplitude and or displacement. In addition, the surface features described above with respect to FIGS. 2-17B can be configured so as to be defined by either or both of the foregoing mathematical expressions relating to amplitude and displacement.
Likewise, the undulations or protuberances on a first portion of the surface can have consistently varying amplitudes that vary according to a different from consistently varying amplitudes on another portion of the surface, with each set of varying amplitudes being governed by a separate mathematical equation of the form given above. For example, in one embodiment, A 1 ,i =r i n1 K 1 ,i A 1 ,0 and A 2 ,1 =r i n2 K 2 ,i A 2 ,0. Similarly, portion of said surface which can also be defined by mathematical equations of the form D 1i =r m1 K 1 ,i D 01 and D 2i =r m2 K 2 ,i D 2 ,0.
While various preferred embodiments of the invention have been shown and described, modifications thereof can be made by one skilled in the art without departing from the spirit and teachings of the invention. For example, the insert and/or substrate need not be round, but may be ovoid, truncated, or any of several other known cutter shapes. | A supporting substrate for supporting a diamond layer on a cutting element is disclosed which has an irregular surface defining the interface between the substrate and the diamond layer. The irregularities in the surface may have varying amplitudes, varying frequencies, or both and can vary according to defined mathematical expressions. The irregularities may assume recognizable geometric forms, such as spiral, circle or wave configurations, or may be arranged in an irregular manner. The surface is constructed with or without a plane of symmetry and may have different average amplitudes and/or frequencies in different areas. | 1 |
FIELD OF THE INVENTION
[0001] The present invention relates to a bioreactor and method for producing microbial cellulose, and more particularly to a bioreactor and method for simultaneously producing tubular microbial cellulose and sheets of microbial cellulose.
DESCRIPTION OF PRIOR ART
[0002] A number of bacteria, and particularly strains of Acetobacter, can be cultivated to produce bacterial cellulose. In the presence of sugar and oxygen, cells of Acetobacter synthesize cellulose extracellularly in the form of fibrils attached to the cell. The fibrils produced by cells incubated in a static culture intertwine with one another to form a hydrophilic network known as a pellicle. This pellicle forms on the air/liquid interface of the motionless and undisturbed culture which is usually contained in shallow trays. Coherent gel-like microbial cellulose pellicles have many uses such as in wound dressings, paper, cosmetics and speaker vibration membranes, after removal of the cells.
[0003] Conventionally, the production of bacterial pellicle is carried out under the condition of static cultivation, which is not only laborious but time-consuming. In U.S. Pat. No. 6,071,727, a rotary disk bioreactor used for producing pellicular microbial cellulose is disclosed; the bioreactor includes a trough holding a liquid medium for microbial cultivation at bottom thereof; a shaft, and a series of parallel circular disks mounted on the shaft; in which an outer portion of each of the circular disks are immersed under the horizontal surface of the liquid medium, and the disks have the appropriate mesh size that would allow both the attachment and growth of microbial cellulose producing organisms, so as to allow the organisms to synthesize microbial cellulose extracellularly. The bioreactor further includes a rotating device attached to the shaft in order to rotate the disks. Therefore, when the rotating device is activated, the outer portions of the disks are alternately immersed under the horizontal surface of the liquid medium.
[0004] Pellicles of tubular microbial cellulose are produced according to special needs, such as the making of artificial blood vessels. WO 2007/093445 A1 discloses a hollow module for this purpose, which comprises two glass half-tubes; a glass cylinder, and two O-shaped rings; wherein the two glass half-tubes are mounted onto the glass cylinder by the use of the two O-shaped rings, so that an annular space is formed between them, and an upper slit and a lower slit are also formed between the two glass half-tubes; the upper slit, the lower slit, and the annular space are interconnected. The lower slit is allowed to contact a pellicular microbial cellulose grown over the horizontal surface of a microbial cultivation liquid medium, so that the microbial cellulose grows into the lower slit, the annular space, and the upper slit to form a tubular microbial cellulose. The first embodiment of WO 2007/093445 A1 shows that the growth of microbial cellulose over the horizontal surface of the liquid medium requires seven days, and it takes an additional two to three weeks to grow into tubular microbial cellulose (which has an inner diameter of 3 mm and an outer diameter of 4.5 mm).
[0005] In the patent U.S. Pat. No. 5,246,854, an attached growth biological reactor is disclosed, which comprises a horizontally disposed rigid cylinder having a sufficiently rough outer surface to allow for attachment and growth of filamentous fungi, and the cylinder is rotatable about a longitudinal axis thereof; a trough disposed below the cylinder, which includes a culture medium for at least a portion of the cylinder to be immersed therein; a blade horizontally disposed and in parallel to the cylinder, and the blade can be brought into contact with the cylinder to scrape any substances off the surface of the cylinder; and a rotating device connected to the cylinder for rotating the cylinder. Although the bioreactor can be used to produce filamentous fungi continuously, the cylinder is inadequate to be used to produce tubular microbial cellulose.
[0006] The above-mentioned patents have been included in this disclosure by reference.
[0007] Though the aforesaid patents have disclosed methods and modules for the production of tubular microbial cellulose, the production efficiency and modules can be further enhanced still. This is especially true as the requirement for larger tubular microbial cellulose increases. For example, in regard to food casing used in the food industry (especially the vegetarian casing, as the microbial cellulose is regarded as a type of vegetarian food), the current production efficiency and modules have been found to lag behind the actual requirements from the industry.
SUMMARY OF THE INVENTION
[0008] A primary objective of the present invention is to provide a novel module for producing tubular microbial cellulose.
[0009] Another objective of the present invention is to provide a method for producing tubular microbial cellulose.
[0010] Another objective of the present invention is to provide a module for simultaneously producing tubular microbial cellulose of different diameters.
[0011] Yet another objective of the present invention is to provide a method for simultaneously producing tubular microbial cellulose of different diameters.
[0012] A further objective of the present invention is to provide a method for simultaneously producing tubular microbial cellulose and sheets of microbial cellulose.
[0013] In order accomplished the aforesaid objectives, a bioreactor for producing microbial cellulose constructed according to the present invention comprises:
a container for holding a liquid medium for microbial cultivation; and a horizontal module having hollow tubes being fitted together at an interval or separated from one another, said horizontal module being horizontally rotatably disposed in said container, so that each of said hollow tubes is alternately partially immersed in the liquid medium held in said container, and partially exposed above a horizontal surface of the liquid medium.
[0016] The present invention also provides a method for producing microbial cellulose, comprising the following steps:
preparing a liquid medium having cellulose-producing microorganisms in a container; horizontally rotating multiple hollow tubes that are fitted together at an interval or separated from one another, such that each of the hollow tubes is alternately partially immersed in the liquid medium and partially exposed above the horizontal surface of the liquid medium, so as to allow the microorganisms to form microbial cellulose on an outer surface of each of the hollow tubes, as well as forming sheets of microbial cellulose on a horizontal surface of the liquid medium not being disturbed by the hollow tubes in the container; and removing the microbial cellulose from the outer surfaces of each of the hollow tubes, thereby obtaining tubular microbial cellulose; wherein each of the hollow tubes has a rough outer surface and a smooth inner surface.
[0020] The present invention has the advantages of being able to produce tubular microbial cellulose of large diameters at high production efficiency. Another advantage of the invention is that tubular microbial cellulose of different diameters can be produced simultaneously. The invention is also advantageous in that tubular microbial cellulose and sheets of microbial cellulose can be produced simultaneously.
BRIEF DESCRIPTION OF DRAWINGS
[0021] FIG. 1 is a perspective view that shows a horizontal module assembled from fitting three hollow tubes together according to a preferred embodiment of the invention.
[0022] FIG. 2 is a lateral view that shows a bioreactor according to a preferred embodiment of the invention, in which the container 30 is transparent.
[0023] FIG. 3 is a lateral view that shows a spacer according to another preferred embodiment of the invention.
[0024] FIG. 4 is a lateral view that shows a bioreactor according to another preferred embodiment of the invention, in which the container 30 is transparent.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0025] FIGS. 1 and 2 show a horizontal module 10 assembled by fitting three hollow tubes together according to a preferred embodiment of the invention. The horizontal module 10 includes three hollow tubes 11 , 12 , and 13 , which have diameters of 30 mm, 40 mm, and 50 mm, respectively, and a wall thickness of 1.0 mm; and two spacers 20 . Each of the spacers 20 has a cross-shaped section 21 and a shaft 22 . The cross-shaped section 21 has three groups of joining clefts 23 surroundingly disposed around a central point of the cross, and each group includes four joining clefts 23 that are spaced at 5 mm from the next group of joining clefts 23 . The first group of four joining clefts are disposed at 15 mm from the central point of the cross, and are used to join with and hold an end of the first hollow tube 11 (with a diameter of 30 mm); the second group of four joining clefts are disposed at 20 mm from the central point of the cross, and are used to join with and hold an end of the second hollow tube 12 (with a diameter of 40 mm); while the third group of four joining clefts are disposed at 25 mm from the central point of the cross, and are used to join with and hold an end of the third hollow tube 13 (with a diameter of 50 mm). The three hollow tubes 11 , 12 , and 13 have one end respectively joined with the three groups of joining clefts 23 of a first spacer 20 , with an interval of 5 mm between the hollow tubes as described above. Subsequently, the same steps are repeated to have another ends of the three hollow tubes 11 , 12 , and 13 respectively joined with the joining clefts of a second spacer 20 , with an interval of 5 mm between the hollow tubes. By assembling the components according to the aforesaid description, two shafts 22 that extend horizontally from the spacers 20 can be observed (the shafts have an identical axis of horizontal rotation), as well as the horizontal module 10 that is assembled by fitting the three hollow tubes 11 , 12 , and 13 together at an interval from one another.
[0026] Each of the three hollow tubes 11 , 12 , and 13 has a rough outer surface and a smooth inner surface. More preferably, the rough outer surface has a regular texture 14 to allow for attachment and even growth of microorganisms thereon.
[0027] Similarly, the horizontal module 10 of FIGS. 1 and 2 can also be assembled by using a spacer 20 A having a Y-shaped section 21 A shown in FIG. 3 . When comparing the spacer 20 A with the spacer 20 of FIGS. 1 and 2 , it can be observed that the only difference being that the former has a Y-shaped section 21 A and the latter has a cross-shaped section 21 , whereas both have identical shafts 22 and joining clefts 23 .
[0028] FIG. 2 shows the horizontal module 10 , as well as a container 30 holding a liquid medium 40 for microbial cultivation. The horizontal module 10 and the container 30 are the main components that make up the bioreactor for producing microbial cellulose according to the invention, in which the container 30 has two semicircular indentations 31 disposed on upper edges of both lateral sides thereof, so as to be joined with and hold the shafts 22 of the horizontal module 10 . Therefore, the horizontal module 10 can be disposed in the container 30 for horizontal rotation, and each of the three hollow tubes 11 - 13 is alternately partially immersed in the liquid medium 40 held in the container 30 , and partially exposed above the horizontal surface of the liquid medium 40 . One of the shafts 22 further comprises a notch 24 at an end thereof, and the notch 24 is able to be coupled to a corresponding linear button (not shown in the drawing) of a transmission shaft, such that when the transmission shaft is driven into rotation by a motor, the horizontal module 10 of FIG. 2 is allowed to rotate horizontally.
[0029] Further variations may be applied to the bioreactor of the invention. For instance, the horizontal module 10 of FIGS. 1 and 2 can be increased to two, or the horizontal module 10 may have one or two hollow tubes added to or taken from the existing three.
[0030] FIG. 4 shows a bioreactor according to another preferred embodiment of the invention, in which all of the components of the bioreactor are identical to those shown in FIG. 2 , except that two horizontally separated tubes having a diameter of 50 mm are used, and the components similar to those of FIG. 2 are labeled by similar numbers and symbols.
[0031] The bioreactor of the present invention may be further comprised of a lid for covering on top of the container 30 , so as to minimize contamination of the liquid medium 40 by various bacteria from the air. When a lid is included, a height of surrounding walls of the container 30 must be increased to make it higher than the highest part of the horizontal module 10 , so that the lid can cover the container properly. Selectively, the bioreactor of the present invention may be placed in an environment not contaminated by various bacteria to carry out cultivation of microorganisms.
[0032] A microorganism that is adequate to be applied in the method for producing microbial cellulose according to the invention is Gluconacetobacter xylinus.
[0033] According to the present invention, the method for producing microbial cellulose includes the cultivation of microorganisms by using the aforesaid bioreactor of the invention, under the conditions described in prior arts (the conditions described in the patents mentioned in Background of the Invention of this disclosure, for instance). As a result, the microorganisms are allowed to form tubular microbial cellulose on the outer surfaces of each of the hollow tubes 11 - 13 , as well as forming sheets of microbial cellulose on the horizontal surface of the liquid medium not being disturbed by the hollow tubes in the container 30 . When harvesting the microbial cellulose, the horizontal module 10 is removed from the container and then disassembled. Subsequently, the hollow tubes 11 - 13 are separated from one another, and because the outer surfaces of the hollow tubes are rough and the inner surfaces are smooth, the microbial cellulose formed by the microorganisms predominately adhere to the rough surfaces. Therefore, the hollow tubes can be separated from one another easily, thereby resulting in hollow tubes having a layer of microbial cellulose on outer surfaces thereof, for example without having the inner surface of the outer most hollow tube 13 adhered to the microbial cellulose on the outer surface of the middle hollow tube 12 , which allows the hollow tubes to be removed easily and prevents the microbial cellulose from being damaged structurally. The layer of microbial cellulose is then peeled off the outer surfaces of the hollow tubes, followed by the removal of microorganisms thereon, thereby obtaining a product of tubular microbial cellulose. Selectively, the tubular microbial cellulose may be further dried and hydrated. After removing the horizontal module 10 from the container 30 , the method further comprises a step of obtaining sheets of microbial cellulose from the liquid medium 40 held in the container, and then removing the microorganisms thereon, thereby resulting in a product of sheets of microbial cellulose. Selectively, the sheets of microbial cellulose may be further dried and hydrated.
[0034] The bioreactor of the invention can not only be used to produce tubular microbial cellulose of different diameters, but also effectively reduces the cultivation time and increases the yield of microbial cellulose for every unit of time/space.
[0035] The bioreactor of the invention can not only be used to cultivate filament-producing microorganisms such as fungi and Actinobacteria, but also microorganisms that produce solid-state products as well. When cultivating microorganisms that need to be cultured anaerobically, the culture medium may be gently stirred to promote even mixing of the microorganisms with the medium, which consequently elevates the usage efficiency of the culture medium.
[0036] The bioreactor of the invention can be used in the production of casing applied in foods, and also further applied in the production of biomedical materials.
[0037] The present invention can be better understood by referring to following embodiments thereof; the embodiments are only intended to be used to elucidate the invention, and are not to be used to limit the scope of the invention in any ways.
EXAMPLE 1
Three Hollow Tubes Fitted Together as a Group
[0038] In this example, the bioreactor shown in FIGS. 1 and 2 was used, wherein the container 30 has a length of 33 cm, a width of 23 cm, and a height of 4 cm, and the three hollow tubes 11 - 13 have a length of 30 cm. The shafts 22 were driven into rotation by a motor at 10 rpm. Consequently, the horizontal module 10 was rotated horizontally at 10 rpm as well.
[0039] The bioreactor was placed in an environment free of contaminating bacteria in order to carry out microbial cultivation, in which the liquid medium 40 held in the container 30 was 35 mm of height, and the culture temperature was 30° C. The liquid medium 40 was a pre-agitated culture prepared in advance. The pre-agitated culture was a liquid medium comprising the ingredients listed in the following table and 5% microorganisms, the culture was incubated free of contaminating bacteria at 120 rpm and 30° C. for two days, and was filled with Gluconacetobacter xylinus by the time the incubation was completed.
[0000]
Sucrose
5%
Yeast extract
0.5%
(NH 4 ) 2 SO 4
0.5%
KH 2 PO 4
0.3%
MgSO 4 •7H 2 O
0.005%
[0040] The cultivation was carried out under room temperature and normal atmospheric environment for seven days.
[0041] Overall, 1.62 g/L of sheets of bacterial cellulose was obtained from the undisturbed portion of liquid medium, and three different sizes of tubular bacterial cellulose, which weighed 1.425 g/L in total; were obtained from the horizontal module, and resulted in a total harvest of 3.045 g/L in this example.
EXAMPLE 2
Two Hollow Tubes Fitted Together as a Group
[0042] The steps and the bioreactor employed in Example 1 were also used in this embodiment, except that the second hollow tube (with a diameter of 40 mm) from the three hollow tubes was not used.
[0043] Overall, 1.745 g/L of sheets of bacterial cellulose was obtained from the undisturbed portion of liquid medium, and two different sizes of tubular bacterial cellulose, which weighed 1.815 g/L in total; were obtained from the horizontal module, and resulted in a total harvest of 3.56 g/L in this example.
EXAMPLE 3
A Single Hollow Tube
[0044] The steps and the bioreactor employed in Example 1 were again used in this embodiment, except that the first and the second hollow tubes (with a diameter of 30 mm and 40 mm, respectively) from the three hollow tubes were not used.
[0045] In this example, 1.745 g/L of sheets of bacterial cellulose was obtained from the undisturbed portion of liquid medium, and one tubular bacterial cellulose, which weighed 0.77 g/L in total; was obtained from the horizontal module, and resulted in a total harvest of 2.515 g/L.
EXAMPLE 4
Two Separated Hollow Tubes
[0046] The steps and the bioreactor employed in Example 3 were used in this embodiment, except that two separated hollow tubes with a diameter of 50 mm positioned in parallel to each other were used. The two separated and parallel hollow tubes were kept from each other at a minimal distance of 65 mm.
[0047] Overall, 2.15 g/L of sheets of bacterial cellulose was obtained from the undisturbed portion of liquid medium, and two tubular bacterial cellulose products, which weighed 2.255 g/L in total; were obtained from the horizontal module, and resulted in a total harvest of 4.405 g/L in this embodiment.
[0000]
Three
Hollow Tubes
One
Two
Fitted Together
Single
Separated
(50 mm +
Two Hollow Tubes
Hollow
Hollow
40 mm +
Fitted Together
Tube
Tubes
g/L
30 mm)
(50 mm + 30 mm)
(50 mm)
(2 × 50 mm)
Tubular
1.425
1.815
0.77
2.255
Sheets
1.62
1.745
1.745
2.15
Total
3.045
3.56
2.515
4.405
[0048] The table above lists the total yields of microbial cellulose from Examples 1-4, which shows that the yield of microbial cellulose is the highest when two separated hollow tubes are used in the cultivation. The inventors deduce that a possible reason for the results is that two separated hollow tubes could produce stronger disturbances onto the liquid medium, which leads to more even distribution of the microorganisms in the liquid medium held in the container, and thus the usage efficiency of the liquid medium is higher than in other cases. Unexpectedly, the tubular bacterial cellulose yield per unit of hollow tube from Example 4 (two separated hollow tubes) is threefold that of Example 3 (a single hollow tube), instead of the predicted twofold.
[0049] The present invention has been described with a preferred embodiment thereof and it is understood that many changes and modifications to the described embodiment can be carried out without departing from the scope and the spirit of the invention that is intended to be limited only by the appended claims. | A technique for producing microbial cellulose is provided, including: preparing a liquid medium for microbial cultivation in a container; horizontally rotating multiple hollow tubes that are fitted together or separated from one another, so that each of the hollow tubes is alternately partially immersed in the liquid medium and partially exposed above the horizontal surface of the liquid medium; wherein each of the hollow tubes has a rough outer surface and a smooth inner surface, so as to allow microorganisms to form microbial cellulose on the outer surface of each hollow tube, as well as forming sheets of microbial cellulose on the horizontal surface of the liquid medium not being disturbed by the hollow tubes, and removing the microbial cellulose from the outer surfaces of the hollow tubes in order to obtain tubular microbial cellulose. In addition, the sheets of microbial cellulose are also harvested from the liquid medium. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to devices for hanging picture frames to walls and more particularly to a non-removable device for hanging a picture frame to a wall.
2. Background of the Invention
In many public areas where art work is displayed, such as hotels, motels, or the like, it is desirable to mount the art work on the wall in such a manner that it can not easily be removed. The conventional means for hanging a picture, wherein a cable strung across the back of the frame is hooked on a hook on the wall, makes it very easy for art work to be stolen.
A number of devices have been developed for mounting pictures or mirrors on a wall in a manner that prevents easy removal. The most common method used for mounting works of art mounted in wooden picture frames is to simply screw the wooden picture frame to the wall. This causes disfiguration of the front surface of the wooden picture frame, however, and is aesthetically unpleasing.
The present invention comprises an improvement in non-removable or theft-proof picture frame mounting devices that provides a simple, easy to use, and inexpensive mounting device that discourages theft of art work.
SUMMARY OF THE INVENTION
In accordance with the present invention, a non-removable hanger for mounting a picture frame on a wall comprises a pair of elongated hanger members that fit behind the vertical sides of the picture frame. Fasteners are provided for pivotably attaching lower ends of the hanger members to the back surfaces of opposite vertical sides of the picture frame, the hanger members being attached to the frame such that the upper ends of the hanger members are pivotal outwardly to an accessible position on the outer side of the picture frame. Fasteners also are provided for alternately pivotably attaching the outwardly extending upper ends of the hanger members to the wall, such that after the hanger members are both attached to the wall and the picture frame is suspended by the hanger members, the hanger members are substantially in a vertical position with the upper ends of the hanger members positioned behind the vertical sides of the picture frame.
A releasable spring locking device interconnecting the hanger member and the back of the picture frame prevents removal of the picture frame by pivoting the picture frame so as to expose the fasteners holding the ends of the hanger members to the wall. A number of different types of locking mechanisms can be employed to accomplish this locking function.
These and other features and advantages of the present invention will hereinafter appear, and, for purposes of illustration, but not of limitation, preferred embodiments of the present invention are described in detail below and shown in the appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front elevational view of a picture frame being mounted to a wall using the picture hanger of the present invention, showing the hanger member on the right side of the picture frame (FIG. 1 orientation) being mounted to the wall, with the left hand hanger member still being unmounted.
FIG. 2 is the same view as FIG. 1, showing the hanger member on the left hand side of the picture frame being mounted on the wall after the right hand member has been mounted on the wall.
FIG. 3 is the same view as FIGS. 1 and 2 showing the picture frame after it is fully mounted on the wall.
FIG. 4 is a face view of the front surface of the hanger member of the present invention.
FIG. 5 is a face view of a second embodiment of a hanger member of the present invention.
FIG. 6 is an end view of the hanger member shown in FIG. 5.
FIG. 7 is a side view of the hanger member shown in FIG. 5.
FIG. 8 is a perspective view of the hanger member shown in FIGS. 5, 6 and 7.
FIG. 9 is an exploded perspective view of a third embodiment of a hanger member constructed in accordance with the present invention, showing the manner in which the hanger member is attached to the back of a frame.
FIG. 10 is a perspective view of still another embodiment of the hanger member of the present invention.
FIG. 11 is a perspective view showing a hanger release tool employed in the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now to the drawings, a non-removable hanger assembly 10 is shown at various stages of being mounted on a picture frame 16 in FIGS. 1-3, and details of various embodiments of hanger members are shown in FIGS. 4-10.
The hanger assembly 10 of the present invention comprises a pair of hanger members 12 and 14 attached by fasteners to opposite vertical sides of a picture frame 16. As shown in FIG. 4, each hanger member 12 comprises a flat elongated plate or clip having spaced openings 18 and 20 at upper and lower ends thereof, respectively, for receiving threaded fasteners 22 and 24, respectively. Openings 18 and 20 are countersunk on opposite sides of the plate in the manner shown in FIGS. 7 and 8.
Hanger member or clip 14 is constructed in substantially the same manner as the basic clip 12, except that it includes a spring locking device 26, several embodiments of which are disclosed in FIGS. 5-10.
Deferring consideration of the locking device for the present moment, the clips are mounted to the picture frame and the picture frame mounted to the wall by the following method: First, two clips are mounted at the same position on opposite vertical sides of the picture frame. Desirably, they are mounted to the picture frame approximately 1/3 of the distance from the top of the picture. Fasteners fit within the countersunk openings in the clips so that the fasteners do not extend outwardly beyond the flat surfaces of the clips facing the wall. With the clips constructed in this manner, the fasteners do not scratch the wall as the picture is pivoted back and forth on the wall in mounting the frame on the wall.
After the clips have been mounted to the back of the frame, clip 12 is pivoted outwardly to the right, in the manner shown in FIG. 1. The clips are formed so that after they have been mounted on the picture frame, the other end of the clip (referred to as the upper end of the clip by virtue of its position when the picture frame is hanging from the wall) extends outwardly from the picture frame and the opening in the upper end of the clip is accessible. Fastener 22 is then inserted through opening 18 in the upper end of the clip and is screwed to the wall. The fasteners nest in the countersunk surface in the clips so the heads of the fasteners lie below the surface of the clip, thereby preventing the fasteners from scratching the back of the frame.
After the right hand clip 12 has been mounted, the frame is pivoted to the right (FIG. 1 orientation) about the axis of fastener 22 until clip 12 extends inwardly from the frame and fastener 22 lies inside the fastener 24 (FIG. 2). At this point, hanger member or clip 14 is pivoted upwardly to the horizontal position shown in FIG. 2, and fastener 28 is inserted through the opening in the upper end of that clip and screwed to the wall. Fastener 30 holds the lower end of clip 14 to the back of the frame.
After fastener 28 has been screwed to the wall, the picture frame is then pivoted in a clockwise direction downwardly to the position shown in FIG. 3. As shown, the picture frame is suspended from the hanger in this position, and the hanger members are positioned vertically behind the vertical sides of the frame, with the upper ends of the hanger members being concealed from view.
The foregoing structure is adequate in many cases to prevent theft of pictures mounted on the wall. With the structure employing only clips of the type shown in FIG. 4, however, it would be possible to pivot the frame back and forth to remove the hanger members from the wall and thereby remove the picture from the wall. To prevent this, locking member 26 is employed to lock the frame in the vertical position shown in FIG. 3 after both hanger members have been mounted to the back of the frame and to the wall. Several constructions of locking members are shown in FIGS. 5-10.
In FIG. 5, hanger member 14 comprises an elongated flat bar having flat upper and lower surfaces 32 and 34. These surfaces engage the back of the frame and the wall and are smooth to prevent scratching of the frame and wall. The bar can be formed of a moldable plastic material or metal. A longitudinally oriented rectangular opening or recess 36 is formed in surface 32. A longitudinal opening 38 extends between ends 40 and 42 of the bar through recess 36. A transverse opening 44 also extends through the recess through sides 46 and 48 of the bar. An upper end opening 50 having a countersunk portion adjacent side 32 and an opening 52 having a countersunk portion adjacent side 34 are formed through the hanger member for mounting the hanger member on the frame and wall. A curved spring clip 54 has ends 56 and 58 that fit within the interior of channel 38 and a central portion 60 that protrudes outwardly from surface 32 at an oblique angle. Central portion 60 of the spring clip fits in a groove 62 in the back of the picture frame (as shown in FIG. 9) after the clip has been mounted to the back of the frame and the frame has been lowered to its supporting position shown in FIG. 3. The spring can be released from the groove simply by slipping a tool with a thin blade, such as tool 64 (shown in FIG. 11) between the hanger member and the back of the frame. The tool will engage the angled surface of the spring member and cause the spring member to be depressed out of engagement with the groove. The picture frame can thereafter be pivoted to remove the hanger members from the wall.
Tool 64 can also be used for another purpose. In order to permit easy pivotal movement of clip 14 before the clip is to be locked in position on the back of the frame, tool 64 can be extended through transverse opening 44 with the central portion 60 of spring 54 depressed below the level of the tool. This will cause the tool to hold the spring in a lowered position within opening 36 in the hanger member. After the clip has been mounted on the back of the frame and on the wall and the frame lowered to its supporting position shown in FIG. 3, the tool can be removed from the transverse opening, permitting the spring clip to deflect through opening 36 into contact with groove 62. Tool 64 can have a flat wide blade 66 at one end thereof to facilitate removal of the spring from the groove and to prevent the tool from going all the way through opening 44 in the clip.
Another embodiment of a hanger member 14' employing a locking device to restrain pivotal movement of the picture frame is shown in FIG. 9. In this embodiment, the hanger member is formed of a relatively thin sheet metal plate and is provided with openings 50' and 52' of the same type employed in hanger member 14. An elongated rectangular opening 68 is formed in the center of hanger member 14' and is positioned so as to be opposite groove 62 in the picture frame. A curved spring member 70 has a flat portion 72 at one end with an opening formed therein that mates with opening 52'. The other end 74 is positioned to abut the surface of hanger member 14' adjacent opening 68. A raised central portion 76 is shaped so that it fits through opening 68 and protrudes into opening 62 in the picture frame. The spring member is mounted to the picture frame along with the hanger member 14, with fastener 30' extending both through the opening in end 72 and through opening 52' in the hanger member. This spring member can be resiliently moved out of the groove 62 in the same manner as spring 54 is removed.
The hanger member and spring member can be formed of metal or comparable plastic materials having similar qualities of resilience and rigidity. Desirably, hanger member 14 is formed of a rigid metal plate and spring member 70 is formed of spring steel.
Another embodiment of a hanger member 14" incorporating a locking device is shown in FIG. 10. In this embodiment, hanger member 14" comprises a thin flat plate or clip having openings 50" and 52" substantially as employed in previous embodiments. A spring clip 78 is formed integrally out of a central portion of this member. Spring section 78 can be formed by deflecting a central portion outwardly from the rest of the plate in a stamping operation employing thin metals. Alternatively, section 78 could be an integrally molded portion of a plastic hanger member of substantially the same design.
It is conceivable that other types of locking devices could be employed to lock the hanger members in a vertical position after the hanger members have both been mounted on the wall.
It should be understood that the foregoing embodiments are merely illustrative of the preferred practice of the present invention and that various changes and modifications may be made in the design and construction of the embodiments disclosed herein without departing from the spirit and scope of the present invention. | A non-removable hanger for a picture frame comprises a pair of flat hanger members having openings at each end, threaded fasteners for pivotably attaching lower ends of the hanger members to opposite vertical sides of the frames and threaded fasteners for attaching upper ends of the hanger members to the wall. The hanger members are attached to the wall after being attached to the back of the frame by rotating or pivoting the picture frame against the wall so that the ends of the hanger members are alternately exposed. The exposed ends are screwed into the wall. A spring lock engages the hanger members and prevents them from pivoting once the frame is mounted and positioned in its proper vertical position. | 0 |
BACKGROUND OF THE INVENTION
[0001] 1. Technical Field
[0002] The present invention relates to a motor vehicle battery having a disconnect switch.
[0003] 2. Description of Related Art
[0004] Motor vehicle batteries are known to discharge upon storage, thereby requiring recharging or replacement following storage for an extended time. In addition, motor vehicle batteries sometimes produce an explosion when a load is connected to the battery terminal. Battery disconnect switches are a known solution to the former problem. The present invention addresses both the former problem and the latter problem.
[0005] U.S. Pat. No. 6,744,344 discloses a disconnect switch for the load circuit of a vehicle battery which includes a movable contact element and a stationary contact element that are linked with a locking mechanism. For releasing the locking mechanism a shape-memory alloy release element is used that contracts when heated. For closing the locking mechanism a shape-memory alloy spring element is provided that induces closure of the mechanism by expansion.
[0006] U.S. Pat. No. 6,492,745 discloses a battery control system for controlling the connection of a plurality of batteries to a load. The system comprises a plurality of switches and a plurality of controllers. Each switch is operable to connect or disconnect one of the batteries from the load. Each controller is operatively coupled to one of the switches. Each controller is operative to cause one of the switches to disconnect one of the batteries from the load. Each controller has an input and an output for communicating with another controller wherein the controllers communicate with each other to limit the number of batteries that can be disconnected from the loads.
[0007] U.S. Pat. No. 6,049,140 discloses a manually reversible battery disconnection system for mounting directly on a terminal of a battery of a motor vehicle. The system includes a housing; a battery terminal connector secured to the housing; a normally closed electrical switch mounted inside the housing; an electrical conductor connected to the battery terminal connector and to one side of the switch; one or more fuses mounted inside the housing, and connected between the other side of the switch and output terminals mounted on the housing; a sensor for detecting an adverse condition; an electromagnetically operated device mounted inside the housing and electrically connected to the sensor, mechanically connected to the switch, and actuable on receipt of an adverse condition signal from the sensor to open the switch; and a manual control mounted on the housing and mechanically connected to the switch for manually operating the switch.
[0008] However, the aforementioned battery disconnect switches do not provide a sealed environment for establishing or preventing the point of contact with the battery terminal.
[0009] Thus, there exists a need for a motor vehicle battery containing an internal terminal disconnect switch that provides a sealed, and therefore safe, contact point with the battery terminal. The present invention substantially fulfills this need.
SUMMARY OF THE INVENTION
[0010] The present invention is directed to a motor vehicle battery comprising an internal terminal disconnect switch for selectively preventing current flow from said motor vehicle battery, said internal terminal disconnect switch comprising: (a) a housing enclosing the contact point between an external terminal of said battery and a corresponding internal terminal, said housing comprising a plurality of seals for isolating the internal environment of said housing from the environment external to said housing; and (b) means for moving said external terminal of said battery relative to its corresponding internal terminal within said housing, wherein contacting said external terminal to said internal terminal permits current flow from the battery, and wherein moving said external terminal away from said internal terminal to a position in which said external terminal and said internal terminal are not in contact with each other prevents current flow from the battery. In another embodiment, the present invention provides a motor vehicle battery comprising an internal terminal disconnect switch for selectively preventing current flow from said motor vehicle battery, said internal terminal disconnect switch comprising: (a) a housing enclosing the contact point between an external terminal of said battery and a corresponding internal terminal, said housing comprising a plurality of seals for isolating the internal environment of said housing from the environment external to said housing; and (b) means for moving said internal terminal of said battery relative to its corresponding external terminal within said housing, wherein contacting said internal terminal to said external terminal permits current flow from the battery, and wherein moving said internal terminal away from said external terminal to a position in which said internal terminal and said external terminal are not in contact with each other prevents current flow from the battery.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The invention will be better understood and objects other than those set forth above will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein:
[0012] FIG. 1 is a cross-sectional view of an embodiment of the present invention.
[0013] FIG. 2 is a cross-sectional view of an embodiment of the present invention in which the internal terminal disconnect switch includes a spring which facilitates movement of the batter external terminal relative to its corresponding internal terminal.
[0014] FIG. 3 is a cross-sectional view of an embodiment of the present invention in which the internal terminal disconnect switch operates by moving the position of the internal terminal relative to the external terminal.
[0015] FIG. 4 is a cross-sectional view of an embodiment of the present invention.
[0016] In the following description of the invention similar reference characters refer to similar parts throughout the several views of the drawings.
DETAILED DESCRIPTION
[0017] FIG. 1 show motor vehicle battery 5 having an external housing 10 , electrolyte solution 20 , cell plates 30 , internal terminal disconnect switch housing 40 , internal terminal 50 , seals 60 , external terminal 70 , manual control 80 , sealed environment 90 , opposite terminal 100 and vent cap 110 . In operation, manual control 80 is mechanically connected to external terminal 70 and allows a user to push external terminal 70 down so as to contact internal terminal 50 , thereby allowing current to flow from motor vehicle battery 5 to an external load (not shown). Seals 60 may be affixed to housing 40 , external terminal 70 and/or internal terminal 50 . As shown, the point of contact between external terminal 70 and internal terminal 50 occurs in a sealed environment 90 .
[0018] Alternatively, when motor vehicle battery 5 is to be stored for an extended period of time, manual control 80 allows a user to pull external terminal 70 up so as to not contact internal terminal 50 , thereby preventing motor vehicle battery 5 from discharging over time. In addition, when it is desired to connect an external load to battery 5 under enhanced safety conditions, manual control 80 allows a user to pull external terminal 70 up to a position where it does not contact internal terminal 50 , thereby allowing a user to connect an external load to external terminal 70 and then push external terminal 70 down to contact internal terminal 50 . This sequence of events completes the electrical circuit within sealed environment 90 rather than in an open, oxygen rich environment.
[0019] FIG. 2 show motor vehicle battery 5 having an external housing 10 , electrolyte solution 20 , cell plates 30 , internal terminal disconnect switch housing 40 , internal terminal 50 , seals 60 , external terminal 70 , manual control 80 , sealed environment 90 , opposite terminal 100 , vent cap 110 and spring 120 . Spring 120 is affixed to housing 40 . In operation, spring 120 facilitates vertical movement of external terminal 70 along a vertical axis relative to the internal terminal 50 . FIG. 3 shows an alternative embodiment of the present invention, in which manual control 80 is mechanically connected to internal terminal 50 and thereby allows a user to push internal terminal 50 down to a position where it does not contact external terminal 70 , thereby allowing a user to connect an external load to external terminal 70 and then pull internal terminal 50 up to contact external terminal 70 . This sequence of events completes the electrical circuit within sealed environment 90 rather than in an open, oxygen rich environment.
[0020] FIG. 3 also shows electrically conductive, flexible connector 120 linking internal terminal 50 to cell plates 30 . Electrically conductive, flexible connector 120 allows internal terminal 50 to move freely between an open position, where internal terminal 50 and external terminal 70 are not in contact, and a closed position, in which internal terminal 50 and external terminal 70 are in contact, while maintaining a continuous connection with cell plates 30 .
[0021] FIG. 4 shows an alternative embodiment of the present invention, in which the contact surfaces of external terminal 70 and internal terminal 50 are designed such that by using manual control 80 to rotate external terminal 70 relative to internal terminal 50 a user can easily toggle the internal terminal disconnect switch between an open position, in which external terminal 70 and internal terminal 50 are not in contact with each other, and a closed position, in which external terminal 70 and internal terminal 50 are in contact with each other. As shown, the point of contact between external terminal 70 and internal terminal 50 occurs in a sealed environment 90 . Of course, although shown in FIG. 4 , it is equally possible to mechanically connect manual control 80 to internal terminal 50 , thereby permitting a user to toggle the internal terminal disconnect switch between an open position (shown) and a closed position (not shown) by rotating internal terminal 50 relative to external terminal 70 .
[0022] While particular embodiments of the present invention have been shown and described herein for purposes of illustration, it will be understood that the invention is not limited thereto. Modifications may be made by persons skilled in the art, particularly in light of the foregoing teachings, without deviating from the spirit and scope of the invention. Accordingly, the invention is not limited except as by the appended claims.
[0023] All of the U.S. patents and published U.S. patent applications referred to in this specification are incorporated herein by reference in their entirety to the extent not inconsistent with the present description. | The present invention is directed to a motor vehicle battery having an internal terminal disconnect switch for selectively preventing current flow from a motor vehicle battery, wherein the disconnect switch comprises a housing enclosing the contact point between an external terminal of the battery and its corresponding internal terminal, wherein the housing comprises a plurality of seals for isolating the internal environment of the housing from the environment external to said housing. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of U.S. application Ser. No. 636,023, filed Nov. 28, 1975, (and now abandoned) which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
In many situations, it is desirable to permanently moor vessels in the ocean, such as storage vessels to receive and store crude oil from an offshore oil field. Such storage vessels are usually extensively modified tankers or barges. In mild environments the storage vessel may be moored by bow hawsers to a single anchor leg mooring or other conventional mooring system. However, storage vessels are frequently located far off shore in severe environments, and, because the storage vessel must remain moored even in storms, high mooring forces are imposed on the mooring system. If the storage vessel is to remain permanently moored, the mooring system must be designed to withstand the highest forces imposed by the most severe environment at the site. To lessen corrosion and wear, it is desirable to have mechanical components, such as mooring and cargo swivels, located so that they will not be subjected to continuous salt water immersion or alternate wetting and dry action which may cause failure of seals and bearings. Because the mooring is permanent, it is further desirable in certain instances to locate swivel seals and bearings where they can be conveniently inspected and maintained.
Several suitable permanent moorings for storage vessels have been of the single anchor leg mooring design, for example see U.S. Pat. Nos. 3,641,602, 3,614,869, and 3,708,811. Other permanent moorings for storage vessels have been of the catenary anchor leg design, for example see U.S. Pat. Nos. 3,538,880 and 3,823,432. However, in both types of such moorings the buoy, located at the water surface, is subjected to high wave forces which increase peak mooring forces. In the single anchor leg mooring the mooring swivel and fluid swivels located beneath the water surface must be removed and brought to the surface for maintenance. In the catenary anchor leg mooring, the anchor system is very expensive, especially in deep water, and the underwater cargo hose system requires frequent maintenance. Other types of permanent mooring systems which employ a yoke type connection are disclosed in U.S. Pat. Nos. 2,882,536 and 3,908,212.
SUMMARY OF THE INVENTION
The present invention relates to moorings and more particularly to a permanent mooring for a vessel such as a storage vessel. According to a preferred embodiment of the present invention in its broadest aspect, there is provided a system for mooring a vessel, typically a tanker, barge or the like, floating on the surface of a body of water, with tension-carrying means, comprising a riser pipe or an anchor chain, which is connected to the bottom of the body of water. Tension-exerting means, provided on the vessel, are connected for coaction with the tension-carrying means for exerting tension on it in order to restore it to a vertical position when it deviates therefrom due to movement of the vessel. Cargo carrying means, including a fluid swivel mounted about a load-carrying shaft, forming part of the mooring leg, is connected between the vessel and piping on the bottom of the body of water. Also according to the present invention, the storage vessel is permanently moored by means of a yoke that is pivoted on the forecastle of the vessel to a riser, which is pivotally attached to a base situated on the ocean floor. The yoke is constantly forced upward by suitable means, such as counterweights, springs, or winches, connected to the yoke and located on the vessel. The force also can be directly applied to the riser or anchor chain. The top of the riser is connected to the end of the yoke by a mooring swivel and a gimbaled mooring table or a universal joint. The fluid swivel is located above the mooring table or about a load-carrying shaft situated below the universal joint. In the present invention the mooring swivel and fluid swivels preferably are situated relatively high above the water surface, so that they will not be subjected to salt water immersion or any alternating wetting and drying action. This swivel location not only prevents failure of seals and bearings but also facilitates inspection and maintenance in contrast to underwater swivels. It is also, however, within the contemplation of this invention to locate the swivels below the water surface.
The present invention can readily be contrasted with a conventional single anchor leg mooring system which relies principally on net buoyancy of the buoy for its restoring elasticity, and which thus permits little variability in the mooring elasticity. The shape of the elasticity curve for the present mooring system can be designed to be more optimum by proper selection of the length of the yoke, of the locations of the mooring yoke pivot points and the cable sheave points, and of the mass of the counterweight, or by the use of variable spring rate devices or other special mechanical arrangements. Damping of the motion of the counterweight, and thus of the yoke and the complete mooring system, can be accomplished by controlled introduction of a fluid into a tank or appropriate chamber which houses the counterweight on the vessel. A yoke, when used, according to the present invention will restrain the permanently moored storage vessel against sway and yaw relative to the mooring and will also prevent it from surging forward on a slack line. Because in the present system the mooring elasticity curve can be more nearly optimized than in conventional mooring systems, and because surge, sway, and yaw motions are minimized, the mooring forces on the present system are expected to be substantially less than those of a conventional mooring system. The absence of a buoy at the water surface in the present system will further reduce forces on the mooring system.
Having in mind the foregoing which will be evident from an understanding of the disclosure, the invention comprises the combination, arrangement and parts disclosed in the presently preferred embodiment of the invention which is hereinafter set forth in such detail as to enable those skilled in the art readily to understand the function, operation, construction and advantages of it when read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a riser and yoke mooring system according to the present invention, with the riser in its undeflected position.
FIG. 2 illustrates a riser and yoke mooring system according to the present invention, substantially like that of FIG. 1, except with the riser in a deflected position as influenced by high mooring forces.
FIG. 3 is an enlarged top plan view of the riser and yoke mooring system of FIG. 1.
FIG. 4 is an enlarged side view of the riser and yoke mooring system of FIG. 1.
FIG. 5 is a cross-sectional view taken substantially on the line 5--5 of FIG 3.
FIG. 6 is a cross-sectional view taken substantially on the line 6--6 of FIG. 3.
FIG. 7 is an alternate embodiment of the present invention wherein a cylinder and piston apply the force.
FIG. 8 is another alternate embodiment of the present invention wherein a winch applies the force.
FIG. 9 illustrates an alternate embodiment of the present invention, wherein the mooring leg comprises an anchor chain instead of a riser pipe.
FIG. 10 is a further modification wherein the mooring leg, shown as an anchor chain, is employed, with the yoke having been omitted.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, wherein like parts are designated by the same reference numerals throughout the several views, there is shown in FIG. 1 a storage vessel generally designated 10 which is permanently moored to the sea floor 18 by a mooring system comprising a structural member such as yoke 20, a mooring leg shown as a riser 12, and a base 16. The vessel shown in a typical modified tanker. It is recognized, however, that other types of vessels such as barges, also may be employed. The base is conventionally secured by virtue of its mass or by means of piles (not shown) to the sea floor 18. The riser 12 is pivotally attached to the base 16 through a conventional universal joint 14 which permits the riser to pivot in any vertical plane. It is recognized that in relatively deep water the mooring leg can be fixedly secured to the sea floor without benefit of a pivot or universal joint, since the small flexure of the riser pipe or other mooring leg member will accommodate movement from its normal vertical axis. The free end of the riser preferably can extend above the surface of the sea. It is also within the contemplation of the present invention to locate the free end of the riser or other type of mooring leg employed beneath the surface of the sea as the situation warrants.
The yoke 20 is pivoted at one end on pins 34 located on opposite sides of the vessel and on an axis transverse to the centerline of the tanker. The yoke is thus free to pivot in a plane vertical with respect to the vessel and containing the vessel centerline, but is restrained against pivoting in a plane horizontal with respect to the vessel. The free end of the yoke extends beyond the bow of the tanker and is connected to the upper end of the riser through the mooring swivel 56 and the gimbaled mooring table 50. While the present preferred embodiment is shown as employing the yoke, it is also possible to design a system which utilized certain basic features and concepts of the present invention without employing a yoke per se. Thus, as shown in certain figures which illustrate modification of the present invention, FIG. 10 in particular, the mooring design can include the use of the mooring leg directly connected between the tension-exerting means on the vessel and the sea floor. This will be explained in further detail hereinafter.
The mooring table 50 is pivoted at the free end of the yoke 20 on horizontal pins 48 having their axis parallel to the axis of the yoke pivot pins 34. The mooring swivel 56 is housed in a mooring ring 52 which is pivoted on pins 54 on an axis in the plane of the mooring table 50 and in a plane vertical with respect to the vessel and passing through the centerline of the vessel. The mooring ring 52 is thus free to gimbal, that is it is free to tilt in any direction with respect to the yoke 20.
The mooring swivel 56, designed to withstand substantial axial thrust, is housed between the mooring ring 52 and the top of the riser 12, and is coaxial with the centerline of the riser. The mooring table 50 is thus free to rotate around the riser 12. This permits the yoke 20 and the vessel 10 to swing completely around the riser 12 and thus swing freely about the mooring base 16.
The outer end of the yoke 20 is lifted upward by means such as cable 38 running to a counterweight 24 located in a tank or chamber 26 in the hull of the vessel 10. Cable 38 is guided over a sheave 42 mounted on posts 44 and over sheave 40 located over the center of chamber 26. The lifting action imparted on the yoke 20 by the counterweight 24 exerts tension on the riser 12. This tensioning action is analogous to the tension applied by the buoy to the anchor leg of a conventional single anchor leg mooring. When environmental forces cause the vessel 10 to move from the neutral position, as shown in FIG. 1, the riser 12 pivots from its normal vertical orientation about the base universal joint 14 into a position such as shown in FIG. 2. Deflection of the riser causes the yoke 20 to dip down, thus lifting the counterweight 24. The vertical component of force in the riser remains essentially the same at any position of deflection, changing slightly with the change in geometry of the system. However, the horizontal component of tensile force in the riser in the deflected position exerts a restoring force tending to draw the vessel back to the neutral position.
In a typical installation, with the base installed in 360 ft. of water and with the riser extending 100 ft. above the water in the undeflected position, the mooring table will drop from 100 ft. to 40 ft. above the water when the moored vessel moves 230 ft. from the neutral position. At this position, the riser is deflected 30° from the vertical and the horizontal force is half of the tension force in the riser. If the cable 38 forms an angle of approximately 60° with the yoke in this deflected position, and is attached at a point near or at the outer end of the yoke, then the horizontal restoring force will be approximately half the weight of the counterweight 24 in the position just described. As shown by the dotted lines in FIG. 1, the tension exerting cable 38 also may be connected directly to the mooring table (38a) at an appropriate location, or may be connected directly to the riser (38b) either above or beneath the seal surface.
The counterweight 24 may be partially filled with a liquid 28, such as water or drilling mud. The mass of the counterweight may be changed by pumping liquid to or from the counterweight by a conventional pump 32 connected to the counterweight through a hose 30.
Fluid cargo may be transferred between the vessel 10 and an underwater pipeline 60 by a system generally comprising hose 62 between the pipeline and piping 64 housed within, as shown in FIG. 1, or attached externally to the riser 12. A fluid swivel 66 mounted on the mooring ring 52 and connected to riser piping 64 as shown in FIG. 4, allows cargo to flow while the vessel rotates about the mooring. Cargo piping 70 on the yoke is connected through hose 68 to the fluid swivel 66 and through hose 72 to piping 74 onboard the vessel. These flexible hose connections account for relative pivoting between the mooring table, the yoke, and the vessel.
In FIG. 7 an alternate embodiment of the present invention is shown in which a mooring swivel 80, designed to withstand substantial axial thrust, is housed near the upper end of the yoke 20 and with its axis substantially perpendicular to the plane of the yoke. The riser 12 is pivotally attached to the mooring swivel 80 through the universal joint 82 which permits the yoke 20 and the vessel 10 to swing completely around the riser 12 and thus swing freely about the mooring base 16.
The outer end of the yoke 20 is lifted upward by means such as cable 38 running over sheave 42 mounted on posts 44, under sheave 46 mounted on the deck of the vessel 10 and connected to a resilient system including a shaft 84 projecting from cylinder 86. Cylinder 86 is firmly mounted to the deck of the vessel. Shaft 84 enters cylinder 86 through a seal 88, and is attached to a piston 90 in sealed sliding contact with the interior of the cylinder, which divides the cylinder into upper and lower chambers of variable volume. When the upper chamber 92 of the cylinder 86 is filled with a pressurized gas or liquid, the piston 90 and shaft 84 are forced downward (to the right in FIG. 7), thus exerting tension in cable 38, lifting yoke 20 upward and exerting tension on the riser 12. As explained above with reference to the preferred embodiment of FIGS. 1-6, this tensioning of the riser 12 tends to restore the mooring and the moored vessel 10 to a neutral position whenever it is disturbed by environmental forces. The pressure within the chamber 92 may be varied though an external pump 94 connected to the chamber through piping 96 to control tension in the cable 38 and in the riser 12, thus changing the characteristics of the mooring system to best suit the environmental conditions.
An external tank 100 may be joined to the piping through a valved orifice 106. Changes in pressure within the chamber 92, caused by changes in the tension in riser 12, will force gas or liquid to flow between the chamber and the tank 100. This flow of liquid or gas will be dampened as it flows through the orifice 106, thus dampening motion of the vessel on the mooring system. The dampening action can be varied by changing the size of the orifice 106. Dampening may be exerted on the mooring system described as the preferred embodiment by placing a liquid 102, such as oil or water, within the counterweight chamber 26. This damping action may be enhanced by making the clearance between the walls of the chamber 26 and the counterweight 24 small. This dampening action may be varied by providing piping or conduit 104 between the upper and lower portions of the chamber on opposite sides of the counterweight 24, as shown in FIG. 1, and by controlling the opening of a valved orifice 106, within this piping to regulate flow therethrough.
Again referring to FIG. 7, the piping 64 within the riser 12 communicates with a conduit formed within a load carrying center shaft (not shown) mounted at the top of the riser and directly below the universal joint 82. This load carrying center shaft is surrounded by a fluid swivel housing 110 mounted on upper and lower fluid swivel joints 112 and 114, which comprises a fluid swivel assembly such as described in U.S. Pat. No. 3,606,397. Cargo flows through the piping 64 to the rotatable housing 110 and then through flexible hose 116 to cargo piping 70 on the yoke 20. If desired, the piping 64 can be situated externally of the riser 12, being secured adjacent its outer surface.
In FIG. 8 another alternate embodiment of the present invention is shown in which a rigid frame structure 120 is mounted on the rigid yoke 20. A cable 122 runs from winch 124 mounted on the deck of the vessel 10 to the top of the rigid frame 120. Tension applied by the winch 124 through the cable 122 causes rigid frame 120 and rigid yoke 20 to pivot about the yoke pivot pins 34, thus lifting the outer end of the yoke 20 and exerting tension on the riser 12. As explained above with reference to the preferred embodiment, this tensioning of the riser 12 tends to restore the mooring and the mooring vessel 10 to a neutral position whenever it is disturbed by environmental forces. Another version may include the location of a counterweight 126 directly on the framework structure 120 at the vessel end as shown schematically by dotted lines, which would avoid the need for employing the cable 122 and associated winch mechanism 124.
Winch 124 may be of the constant tension type, which which exerts a constant tension in the cable 122 while allowing cable to the reled out or reeled in. Alternatively, the cable 122 may be of an elastic material, such as nylon, which will elongate under tension. If the cable 122 is of an elastic material, the end of the cable may be fastened to a strong point on the deck of the vessel 10, instead of to the winch 124.
FIG. 9 illustrates basically the same overall arrangement of the preferred embodiment of FIGS. 1 and 2; however, instead of employing a rigid pipe for the riser 12, the mooring leg comprises an anchor chain 128 connected at one end to the base 16 and at the other or upper end to the outboard end of the rigid yoke 20. The connection of the upper end of the mooring leg to the tension exerting cable 38, either directly or via the yoke, accomplishes the same function described heretofore with reference to the riser pipe, namely exerting tension on the mooring leg in order to cause the vessel to restore to its desired position. Typical use of a mooring leg including an anchor chain can be found in the aforementioned single anchor leg mooring U.S. patents. An anchor chain swivel 130 may be included in the mooring leg to accommodate rotation of the vessel about the mooring point. A fluid swivel assembly, such as that disclosed in U.S. Pat. No. 3,606,397, may also be included in the mooring leg comprising a load-carrying center shaft (not shown) below the yoke an upper housing 132 fixed to this shaft, and a lower housing 134 rotatably mounted on the shaft through swivels 136. Flexible hose 138 connects an underwater pipeline 60 with the lower housing 134, and another hose 116 connects the upper housing 132 to piping on the yoke 20.
Yet another version of the present invention is shown in FIG. 10, wherein the mooring leg comprises the chain 128 which is connected at its free or upper end directly to the cable 38. The cable 38 extends over a sheave 140 on the free or outboard end of yoke 142 to means onboard the vessel for exerting tension thereon, such as those described above, in order to induce tension in the chain. The chain is normally held in a vertical position by the tension applied at its upper end. When the vessel is deflected such that the chain is no longer vertical, the horizontal component of the tension in the chain creates the restoring force which brings the vessel back to its normal and desired position. Thus, any external force which causes the leg to deviate from its normal substantially vertical position would cause horizontal restoring forces to develop in the leg which draws it back to its normal substantially vertical position.
An anchor swivel 130 may be incorporated in the mooring leg. As the cable 38 is connected directly to the mooring leg 128, it is not necessary that the yoke 142 pivot in the manner of the yokes described in the previously described embodiments. A fluid swivel assembly may be incorporated in the mooring leg in the manner described with reference to FIG. 9. An alternative position of the fluid swivel assembly is shown in FIG. 10 in which the load carrying shaft (not shown) and the fixed housing 132 are mounted on the base 16 and the rotatable housing 134 is mounted on swivels 136 to permit it to rotate continuously about the center shaft. The base universal joint 14 is mounted on the top of the center shaft. Cargo flows from the pipeline 60 through the fluid swivel assembly and up through flexible hose 138 to the moored vessel.
While a preferred embodiment and various modifications thereof have been disclosed, it will be apparent to those of ordinary skill in the art upon reading this disclosure, that other modifications and variations can be made. Accordingly, reference should be made to the appended claims for determining the full and complete scope of the present invention. | A vessel such as a storage vessel is permanently moored, by means such as a yoke pivoted on the forecastle of the vessel, to a mooring leg, e.g. a riser or anchor chain, which is attached to a base located on the ocean floor. Mounted on the vessel is tension existing means, for example, counterweights, springs, winches, or the like, operably connected with the mooring leg for applying tension thereto such as by lifting the yoke. The top of the mooring leg is connected to the end of the yoke through a mooring swivel and a gimbaled mooring table or a universal joint. A fluid swivel may be located above the mooring table or about a load-carrying shaft connected to the mooring leg. | 1 |
INCORPORATION BY REFERENCE
This application claims the benefit of U.S. Provisional Patent Application No. 61/108,046 filed Oct. 24, 2008, which is incorporated herein by reference in its entirety. The documents cited or referenced herein (“herein cited documents”), and all documents cited or referenced in herein cited documents, together with any manufacturer's instructions, descriptions, product specifications, and product sheets for any products mentioned herein or in any document incorporated by reference herein, are hereby incorporated herein by reference, and may be employed in the practice of the invention.
FIELD OF THE INVENTION
The present invention relates to a method for synthesizing a group of chemical compounds having antibacterial activity, which are useful in the therapy of bacterial infections in mammals. More specifically, the invention relates to methods for synthesizing the macrolide compounds, e.g. gamithromycin.
Even more specifically, the invention relates to a method of producing gamithromycin utilizing a novel configuration of catalysts, chemical structures, and/or methods.
The present invention also provides a novel method for inhibiting degradation while isolating a structure of a pharmaceutical composition.
BACKGROUND OF THE INVENTION
Macrolides are a group of chemical compounds, some of which have antibacterial activity and are useful in the therapy of bacterial infections in mammals. Macrolide antibiotics include those having a many-membered lactone ring to which are attached one or more deoxy sugar molecules. These antibiotics are generally bacteriostatic, but have been also been shown to be bacteriocidal to some organisms. Macrolide antibiotics are effective against gram-positive cocci and bacilli, although some of them do possess some activity against some gram-negative organisms. Macrolide antibiotics exert their bacteriostatic activity by inhibiting bacterial protein synthesis. (“Goodman & Gillman's the Pharmacological Basis of Therapeutics,” 9th ed., J. G. Hadman & L. E. Limbird, eds., ch. 47, pp. 1135-1140, McGraw-Hill, New York (1996)).
As a class macrolides tend to be colorless and usually crystalline. The compounds are generally stable in near neutral solution, but may be less stable in acid or base solutions. The precursors of macrolide compounds used in the process of the invention (e.g. (9E)-9-deoxy-9-hydroxyiminoerythromycin A (hereinafter “Structure 1”); 9-(Z)-erythromycin oxime (hereinafter “Structure 2”); and 9-Deoxo-12-deoxy-9,12-epoxy-8a,9-didehydro-8a-aza-8a homoerythromycin A (hereinafter “Structure 3”) have been described in U.S. Pat. Nos. 5,202,434 and 5,985,844. Furthermore, Yang et al., Tetrahedron Letters, 1994, 35(19), 3025-3028 and Djokic et al., J. Chem. Soc. Perkin Trans. 1, 1986, 1881-1890 describe the synthesis of macrolide compounds that use these compounds as intermediates. However, the synthesis and isolation of macrolide compounds such as gamithromycin typically requires multiple extractions and phase separations.
Therefore, there is still a need for simplifying the synthesis and isolation of macrolides as well as increasing the stability of the macrolides and intermediates thereof.
Citation or identification of any document in this application is not an admission that such document is available as prior art to the present invention.
SUMMARY OF THE INVENTION
The present invention relates to a novel method of synthesizing macrolide compounds. An embodiment of the present invention may include allowing multiple chemical reactions to proceed without the isolation of chemical intermediates. For example, a chemical may be reduced and subsequently alkylated without isolation of the chemical intermediates. Thus, multiple reactions may occur in one reaction vessel which may allow for a considerable decrease in the cycle-time of the process. In an alternate embodiment, one or more of the intermediates may be isolated prior to reaction.
In an embodiment, (9E)-9-deoxy-9-hydroxyiminoerythromycin A (hereinafter “Structure 1”) may be isomerized to form 9-(Z)-erythromycin oxime (hereinafter “Structure 2”). In some embodiments, a rearrangement may be used to convert 9-(Z)-erythromycin oxime to 9-deoxo-12-deoxy-9,12-epoxy-8a,9-didehydro-8a-aza-8a homoerythromycin A (hereinafter “Structure 3”). Reduction and alkylation may be used to convert 9-deoxo-12-deoxy-9,12-epoxy-8a,9-didehydro-8a-aza-8a homoerythromycin A to gamithromycin. In another embodiment, the amount of by-products resulting from distillations and washes may be reduced.
Further, an embodiment of the invention may include isolation of an intermediate under conditions which are controlled to inhibit degradation of the intermediate.
These and other embodiments are disclosed or are obvious from and encompassed by the following Detailed Description.
It is noted that in this disclosure and particularly in the claims and/or paragraphs, terms such as “comprises”, “comprised”, “comprising” and the like can have the meaning attributed to it in U.S. Patent law; e.g., they can mean “includes”, “included”, “including”, and the like; and that terms such as “consisting essentially of” and “consists essentially of” have the meaning ascribed to them in U.S. Patent law, e.g., they allow for elements not explicitly recited, but exclude elements that are found in the prior art or that affect a basic or novel characteristic of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The following detailed description, given by way of example, but not intended to limit the invention solely to the specific embodiments described, may best be understood in conjunction with the accompanying drawings, in which:
FIG. 1 depicts chemical structures involved in a method for synthesizing gamithromycin.
FIG. 2 depicts chemical structures of degradants of Structure 3 in a method for synthesizing gamithromycin.
FIG. 3 depicts an HPLC trace of a sample of isolated Structure 3.
FIG. 4 depicts an HPLC trace of a sample of isolated Structure 7 obtained using hydrogenation under acidic conditions.
FIG. 5 depicts an HPLC trace of a sample of isolated Structure 7 obtained using hydrogenation under less acidic conditions.
FIG. 6 depicts an HPLC trace of a sample of Structure 8 (Gamithromycin).
FIG. 7 depicts an HPLC trace of a sample of isolated gamithromycin.
FIG. 8 depicts an overlay of an HPLC trace of a convention synthesis method and an HPLC trace of the method described herein.
DETAILED DESCRIPTION
For clarity, the numbering of the macrocyclic lactones and macrocyclic lactams described herein will use the ring numbering used in U.S. Pat. No. 5,202,434, which is incorporated herein by reference in its entirety. The ring numbering of the erythromycin A lactone ring shown below will be maintained throughout this document for the 14-membered ring compounds described. Similarly, the numbering of the 15-membered lactam described shown below will be used for 15-membered ring compounds described herein.
Definitions
Terms used herein will have their customary meaning in the art unless specified otherwise. The organic moieties mentioned in the definitions of the variables of formula (I) or (II) are—like the term halogen—collective terms for individual listings of the individual group members. The prefix C n -C m indicates in each case the possible number of carbon atoms in the group.
The term “alkyl” as used herein, refers to saturated straight, branched, cyclic, primary, secondary or tertiary hydrocarbons, including those having 1 to 20 atoms. In some embodiments, alkyl groups will include C 1 -C 12 , C 1 -C 10 , C 1 -C 8 , C 1 -C 6 or C 1 -C 4 alkyl groups. Examples of C 1 -C 10 alkyl include, but are not limited to, methyl, ethyl, propyl, 1-methylethyl, butyl, 1-methylpropyl, 2-methylpropyl, 1,1-dimethylethyl, pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 2,2-dimethylpropyl, 1-ethylpropyl, hexyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl, 1-methylpentyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, 1,1-dimethylbutyl, 1,2-dimethylbutyl, 1,3-dimethylbutyl, 2,2-dimethylbutyl, 2,3-dimethylbutyl, 3,3-dimethylbutyl, 1-ethylbutyl, 2-ethylbutyl, 1,1,2-trimethylpropyl, 1,2,2-trimethylpropyl, 1-ethyl-1-methylpropyl, 1-ethyl-2-methylpropyl, heptyl, octyl, 2-ethylhexyl, nonyl and decyl and their isomers. C 1 -C 4 -alkyl means for example methyl, ethyl, propyl, 1-methylethyl, butyl, 1-methylpropyl, 2-methylpropyl or 1,1-dimethylethyl.
The term “alkenyl” refers to both straight and branched carbon chains which have at least one carbon-carbon double bond. In some embodiments, alkenyl groups may include C 2 -C 20 alkenyl groups. In other embodiments, alkenyl includes C 2 -C 12 , C 2 -C 10 , C 2 -C 8 , C 2 -C 6 or C 2 -C 4 alkenyl groups. In one embodiment of alkenyl, the number of double bonds is 1-3, in another embodiment of alkenyl, the number of double bonds is one or two. Other ranges of carbon-carbon double bonds and carbon numbers are also contemplated depending on the location of the alkenyl moiety on the molecule. “C 2 -C 10 -alkenyl” groups may include more than one double bond in the chain. Examples include, but are not limited to, ethenyl, 1-propenyl, 2-propenyl, 1-methyl-ethenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1-methyl-1-propenyl, 2-methyl-1-propenyl, 1-methyl-2-propenyl, 2-methyl-2-propenyl; 1-pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl, 1-methyl-1-butenyl, 2-methyl-1-butenyl, 3-methyl-1-butenyl, 1-methyl-2-butenyl, 2-methyl-2-butenyl, 3-methyl-2-butenyl, 1-methyl-3-butenyl, 2-methyl-3-butenyl, 3-methyl-3-butenyl, 1,1-dimethyl-2-propenyl, 1,2-dimethyl-1-propenyl, 1,2-dimethyl-2-propenyl, 1-ethyl-1-propenyl, 1-ethyl-2-propenyl, 1-hexenyl, 2-hexenyl, 3-hexenyl, 4-hexenyl, 5-hexenyl, 1-methyl-1-pentenyl, 2-methyl-1-pentenyl, 3-methyl-1-pentenyl, 4-methyl-1-pentenyl, 1-methyl-2-pentenyl, 2-methyl-2-pentenyl, 3-methyl-2-pentenyl, 4-methyl-2-pentenyl, 1-methyl-3-pentenyl, 2-methyl-3-pentenyl, 3-methyl-3-pentenyl, 4-methyl-3-pentenyl, 1-methyl-4-pentenyl, 2-methyl-4-pentenyl, 3-methyl-4-pentenyl, 4-methyl-4-pentenyl, 1,1-dimethyl-2-butenyl, 1,1-dimethyl-3-butenyl, 1,2-dimethyl-1-butenyl, 1,2-dimethyl-2-butenyl, 1,2-dimethyl-3-butenyl, 1,3-dimethyl-1-butenyl, 1,3-dimethyl-2-butenyl, 1,3-dimethyl-3-butenyl, 2,2-dimethyl-3-butenyl, 2,3-dimethyl-1-butenyl, 2,3-dimethyl-2-butenyl, 2,3-dimethyl-3-butenyl, 3,3-dimethyl-1-butenyl, 3,3-dimethyl-2-butenyl, 1-ethyl-1-butenyl, 1-ethyl-2-butenyl, 1-ethyl-3-butenyl, 2-ethyl-1-butenyl, 2-ethyl-2-butenyl, 2-ethyl-3-butenyl, 1,1,2-trimethyl-2-propenyl, 1-ethyl-1-methyl-2-propenyl, 1-ethyl-2-methyl-1-propenyl and 1-ethyl-2-methyl-2-propenyl.
“Alkynyl” refers to both straight and branched carbon chains which have at least one carbon-carbon triple bond. In one embodiment of alkynyl, the number of triple bonds is 1-3; in another embodiment of alkynyl, the number of triple bonds is one or two. In some embodiments, alkynyl groups include from C 2 -C 20 alkynyl groups. In other embodiments, alkynyl groups may include C 2 -C 12 , C 2 -C 10 , C 2 -C 8 , C 2 -C 6 or C 2 -C 4 alkynyl groups. Other ranges of carbon-carbon triple bonds and carbon numbers are also contemplated depending on the location of the alkenyl moiety on the molecule. For example, the term “C 2 -C 10 -alkynyl” as used herein refers to a straight-chain or branched unsaturated hydrocarbon group having 2 to 10 carbon atoms and containing at least one triple bond, such as ethynyl, prop-1-yn-1-yl, prop-2-yn-1-yl, n-but-1-yn-1-yl, n-but-1-yn-3-yl, n-but-1-yn-4-yl, n-but-2-yn-1-yl, n-pent-1-yn-1-yl, n-pent-1-yn-3-yl, n-pent-1-yn-4-yl, n-pent-1-yn-5-yl, n-pent-2-yn-1-yl, n-pent-2-yn-4-yl, n-pent-2-yn-5-yl, 3-methylbut-1-yn-3-yl, 3-methylbut-1-yn-4-yl, n-hex-1-yn-1-yl, n-hex-1-yn-3-yl, n-hex-1-yn-4-yl, n-hex-1-yn-5-yl, n-hex-1-yn-6-yl, n-hex-2-yn-1-yl, n-hex-2-yn-4-yl, n-hex-2-yn-5-yl, n-hex-2-yn-6-yl, n-hex-3-yn-1-yl, n-hex-3-yn-2-yl, 3-methylpent-1-yn-1-yl, 3-methylpent-1-yn-3-yl, 3-methylpent-1-yn-4-yl, 3-methylpent-1-yn-5-yl, 4-methylpent-1-yn-1-yl, 4-methylpent-2-yn-4-yl or 4-methylpent-2-yn-5-yl and the like.
“Aryl” refers to a monovalent aromatic carbocyclic group of from 6 to 14 carbon atoms having a single ring or multiple condensed rings. In some embodiments, aryl groups include C 6 -C 10 aryl groups. Aryl groups include, but are not limited to, phenyl, biphenyl, naphthyl, tetrahydronaphtyl, phenylcyclopropyl and indanyl. Aryl groups may be unsubstituted or substituted by one or more moieties selected from halogen, cyano, nitro, hydroxy, mercapto, amino, alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, haloalkyl, haloalkenyl, haloalkynyl, halocycloalkyl, halocycloalkenyl, alkoxy, alkenyloxy, alkynyloxy, haloalkoxy, haloalkenyloxy, haloalkynyloxy, cycloalkoxy, cycloalkenyloxy, halocycloalkoxy, halocycloalkenyloxy, alkylthio, haloalkylthio, cycloalkylthio, halocycloalkylthio, alkylsulfinyl, alkenylsulfinyl, alkynyl-sulfinyl, haloalkylsulfinyl, haloalkenylsulfinyl, haloalkynylsulfinyl, alkylsulfonyl, alkenylsulfonyl, alkynylsulfonyl, haloalkyl-sulfonyl, haloalkenylsulfonyl, haloalkynylsulfonyl, alkylamino, alkenylamino, alkynylamino, di(alkyl)amino, di(alkenyl)-amino, di(alkynyl)amino, or trialkylsilyl.
The term “aralkyl” refers to an aryl group that is bonded to the parent compound through a diradical alkylene bridge, (—CH 2 —) n , where n is 1-12 and where “aryl” is as defined above.
“Heteroaryl” refers to a monovalent aromatic group of from 1 to 15 carbon atoms, preferably from 1 to 10 carbon atoms, having one or more oxygen, nitrogen, and sulfur heteroatoms within the ring, preferably 1 to 4 heteroatoms, or 1 to 3 heteroatoms. The nitrogen and sulfur heteroatoms may optionally be oxidized. Such heteroaryl groups can have a single ring (e.g., pyridyl or furyl) or multiple condensed rings provided that the point of attachment is through a heteroaryl ring atom. Preferred heteroaryls include pyridyl, piridazinyl, pyrimidinyl, pyrazinyl, triazinyl, pyrrolyl, indolyl, quinolinyl, isoquinolinyl, quinazolinyl, quinoxalinyl, furanyl, thiophenyl, furyl, pyrrolyl, imidazolyl, oxazolyl, isoxazolyl, isothiazolyl, pyrazolyl benzofuranyl, and benzothiophenyl. Heteroaryl rings may be unsubstituted or substituted by one or more moieties as described for aryl above.
In some embodiments, the invention may include the pharmaceutically acceptable or veterinarily acceptable salts of the compounds shown in FIG. 1 . Such salts are generally prepared as acid addition salts by combining a macrolide compound with one to three equivalents of an appropriate acid in an inert solvent. The salt is recovered by solvent evaporation or by filtration if the salt precipitates spontaneously, or by precipitation using a co-solvent or a non-polar co-solvent followed by filtration. Salts may include, but are not limited to, acetate, benzenesulfonate, benzoate, bicarbonate, bisulfate, bitartrate, borate, bromide, calcium, calcium edetate, edentate, camsylate, carbonate, chloride, clavulanate, citrate, dihydrochloride, edentate, edisylate, estolate, esylate, ethylsuccinate, fumarate, gluceptate, glucoheptonate, gluconate, glutamate, glycollylarsanilate, hexylresorcinate, hydrabamine, hydrobromide, hydrochloride, iodide, isothionate, lactate, lactobionate, laurate, malate, maleate, mandelate, mesylate, methylsulfate, mucate, napsylate, nitrate, oleate, oxalate, pamoate (embonate), palmitate, pantothenate, phosphate/diphosphate, polygalacturonate, salicylate, stearate, subacetate, succinate, tannate, tartrate, teoclate, tosylate, triethiodode, valerate and/or combinations thereof.
In one embodiment, Structure 1 may be isomerized to form Structure 2 as shown in FIG. 1 . In some embodiments, the isomerization may be carried in the presence of one or more reagents. Suitable reagents include, but are not limited to, solvents and bases. Suitable solvents for the transformation may be common protic or aprotic solvents known in the art. The following list of reagents below is illustrative, and it will be clear to one of skill in the art that other bases and solvents known or yet to be discovered in the art should not be excluded.
Suitable bases include, but are not limited to, hydroxides including, but not limited to, lithium hydroxide, sodium hydroxide, potassium hydroxide, cesium hydroxide, calcium hydroxide, magnesium hydroxide, tetramethylammonium hydroxide, benzyltrimethylammonium hydroxide, tetraethylammonium hydroxide, tetrabutylammonium hydroxide and the like; alkoxides including, but not limited to, lithium methoxide, lithium ethoxide, lithium isopropoxide, lithium n-butoxide, lithium sec-butoxide, sodium methoxide, sodium ethoxide, sodium n-propoxide, sodium iso-propoxide, sodium n-butoxide, sodium sec-butoxide, sodium tert-butoxide, sodium trimethylsilanoate, potassium methoxide, potassium ethoxide, potassium tert-butoxide, potassium trimethylsilanoate, potassium sec-butoxide, cesium tert-butoxide, calcium methoxide, magnesium ethoxide, titanium (IV) ethoxide, titanium (IV) isopropoxide, benzyltrimethylammonium methoxide, and the like; carbonates including, but not limited to, potassium carbonate, cesium carbonate, sodium carbonate, and the like; amides including, but not limited to, lithium amide, lithium dimethylamide, lithium diisopropylamide, lithium dicyclohexylamide, lithium bis(trimethylsilyl) amide, sodium amide potassium bis(trimethylsilyl) amide, and the like, amines including, but not limited to, 1,1,3,3-tetramethyl guanidine, 1,8-diazabicyclo[5,4,0]-undec-7-ene, 1,8-bis(dimethylamino)-naphthalene), and the like, and hydrides including, but not limited to, lithium hydride, sodium hydride, potassium hydride, and the like.
Suitable solvents include those solvents miscible with water as well as those that are not miscible with water. In some embodiments, suitable solvents include, but are not limited to, water, methanol, ethanol, isopropanol, normal-butanol, sec-butanol, tert-butanol, diethyl ether, tetrahydrofuran, dimethoxyethane, toluene, dichloromethane, chloroform, dimethylformamide, dimethylacetamide, 1,3-dimethyl-2-imidazolidinone, 1-ethyl-2-pyrrolidinone, 1-methyl-2-pyrrolidinone, hexamethylphosphoramide, nitromethane, acetonitrile, dioxane, pyridine, dimethyl sulfoxide, and the like, and/or combinations thereof.
In one embodiment, Structure 1 may react with a base in the presence of a solvent to form Structure 2. In one embodiment, the base may be lithium hydroxide and the solvent may be ethanol. In certain embodiments, hydrates of the base, such as the monohydrate of lithium hydroxide, are used.
In some embodiments, optimization of the method of the isomerization may include use of a base and solvent combination sufficient to substantially deprotonate the hydroxyimino group (oxime) of Structure 1. In one embodiment, reaction conditions may be controlled to stabilize the oxime anion for the time period necessary to complete the isomerization process.
In another embodiment, an equilibrium condition may be created upon addition of the base to Structure 1. One embodiment may include protonation of oxime anions to give the neutral oxime product mixture from which Structure 2 may be isolated by crystallization, by chromatography followed by crystallization, or by crystallization followed by chromatography. The relative amounts of Structure 1 and Structure 2 in the equilibrium mixture may be controlled by a number of factors. These factors may include, but are not limited to, the strength and quantity of the base reagent, the size and polarizability of the counterion, the reaction solvent, and/or the reaction temperature.
In some embodiments, the isomerization reaction may be carried out at a concentration of about 1% to about 25% weight of Structure 1/volume of solvent. In other embodiments, the concentration of Structure 1 may be about 5% to about 25%, about 5% to about 15%, or about 7% to about 12% by weight of Structure 1/volume of solvent. In a preferred embodiment, the weight of Structure 1/volume of solvent may be about 10%.
In some embodiments, the amount of base used may be in a range from about 1 to about 10 molar equivalents based on the amount of starting Structure 1. In other embodiments, the amount of base may be in a range from about 1 to about 3 molar equivalents. In one preferred embodiment, the process may include using an amount of base having a value of about 2 molar equivalents.
In some embodiments the reaction temperature may be monitored. In an embodiment, conditions of the reaction may be controlled to maintain a temperature within a range from about −10° C. to about 80° C., or from about 0° C. to about 80° C. The temperature may be maintained in a range from about 10° C. to about 70° C. in one embodiment. In another embodiment, a reaction temperature may be maintained within a range from about 15° C. to about 60° C. Another embodiment may include maintaining a reaction temperature within a range from about 20° C. to about 50° C. In still another embodiment, the reaction temperature may be maintained in a range from about 20° C. to about 30° C. Some embodiments may include maintaining a temperature within a range from about 22° C. to about 25° C.
In some embodiments, the reaction time may vary. For example, the reaction may be allowed to run for about 0.5 hours to about 20 days. Another embodiment may include allowing the reaction to run for about 1 hour to about 15 days. In other embodiments, the reaction time may be within a range from about 3 hours to about 5 days. Alternately, a reaction time may be within a range from about 6 hours to about 24 hours in one embodiment. Further, one embodiment may include a reaction time of about 10 hours to about 24 hours. In another embodiment, a reaction time may be within a range from about 20 hours to about 24 hours.
Equilibrium in these reactions may be influenced by a number of factors including, but not limited to, strength and quantity of the base, the size and polarization of a counterion, the reaction solvent, and/or the reaction temperature. Any solvent or base known or yet to be discovered in the art may be used.
One embodiment of the invention may include isolating Structure 2 by any suitable means. For example, in one embodiment, Structure 2 may be isolated using crystallization. In other embodiments, isolation of Structure 2 may include use of chromatography followed by crystallization, or crystallization followed by chromatography. It will be apparent to one of skill in the art that Structure 2 or any other compound of the invention may be crystallized from solution by any method that suitably reduces the solubility of the compound in the solvent. Crystallization methods may include, but are not limited to, reducing the temperature of a solution, addition of an anti-solvent in which the compound is not soluble, formation of an insoluble salt, and the like.
The process utilizes a rearrangement to form a mixture of Structure 3 and Structure 5 from an oxime of Structure 1 or Structure 2. The Beckmann rearrangement of ketoximes (see for example, “Comprehensive Organic Chemistry,” I. O. Sutherland (Ed.),
Pergamon Press, New York, 1979, Vol. 2, pgs. 398-400 and 967-968; and Gawley, Organic Reactions, 1988, 35, 1-420) may lead to carboxamides and, in cyclic systems, to ring expanded lactams. In an embodiment, an acid-catalyzed rearrangement, such as a Beckmann rearrangement, may be utilized to form a mixture from Structure 2. For example, in certain embodiments of the invention, a mixture resulting from a Beckmann rearrangement of Structure 2 may include, but is not limited to 9-deoxo-12-deoxy-9,12-epoxy-8a,9-didehydro-8a-aza-8a homoerythromycin A (hereinafter “Structure 3”) and/or 9-deoxo-6-deoxy-6,9-epoxy-8a,9-didehydro-8a-aza-8a homoerythromycin A (hereinafter “Structure 4”).
Although not wishing to be bound by theory, in an embodiment, the mechanism of the Beckmann rearrangement may involve an initial conversion of the oxime hydroxyl group to a leaving group which is then lost with concomitant migration of the oxime carbon substituent that is situated anti to the leaving group. In aqueous media, an intermediate nitrilium cation thus formed usually reacts with water to afford the amide product. The nitrilium intermediate may be trapped by other suitable nucleophiles thereby leading to imino products, such as imidates and amidines.
The Beckmann rearrangement may be performed in varying conditions including, but not limited to, acidic, basic and neutral conditions. An embodiment may include controlling reaction conditions and/or reagents to give varying proportions of products. Common acidic reagents which may be utilized include, but are not limited to, sulfuric acid including concentrated sulfuric acid, polyphosphoric acid, thionyl chloride, phosphorous pentachloride, sulfur dioxide, formic acid and/or combinations thereof. In some embodiments, a Beckmann rearrangement may occur by heating the oxime with silica gel in a suitable solvent. Suitable solvents include, but are not limited to, aromatic solvents such as toluene or xylene. An alternate embodiment of a Beckmann rearrangement may include heating the oxime under mildly basic conditions in a suitable solvent, including hexamethylphosphoramide.
In one embodiment, a Beckmann rearrangement may include initial O-sulfonylation of the oxime group with a suitable sulfonylating agent. Sulfonylating agents are well known in the art and include, but are not limited to, an alkylsulfonyl halide, arylsulfonyl halide or arylsulfonic anhydride. An intermediate oxime sulfonate formed this way may be isolated or may be converted in situ to the rearranged products. Sulfonylation and rearrangement reactions may be performed in the presence of an organic or inorganic base.
Some embodiments may include sulfonylating reagents for effecting the rearrangement of Structure 2 including, but not limited to, methanesulfonyl chloride, benzenesulfonyl chloride, 4-acetamidobenzenesulfonyl chloride, p-toluenesulfonyl chloride, benzenesulfonic anhydride, p-toluenesulfonic anhydride and/or other sulfonylating reagents known or yet to be discovered in the art. The reaction may be carried out in the presence of an inorganic base including, but not limited to, sodium bicarbonate or potassium carbonate. Alternately, in some embodiments the reaction may occur in the presence of an organic base including, but not limited to, pyridine, 4-dimethylaminopyridine, triethylamine, N,N-diisopropylethylamine, and/or any organic base known or yet to be discovered in the art. Suitable solvents may include, but are not limited to, aqueous mixtures such as aqueous acetone or aqueous dioxane and organic solvents such as dichloromethane, chloroform, ethyl acetate, diethyl ether, tetrahydrofuran, toluene, acetonitrile, pyridine, and the like. In addition, mixtures of organic solvents, especially those containing pyridine, may be used. In an embodiment, the reaction may be performed using about one to about three molar equivalents of the sulfonylating agent and about one or more molar equivalents of base at a reaction temperature of about −20° C. to about 50° C. In one embodiment, pyridine may be used as both solvent and base.
In an embodiment, a distribution of products resulting from a Beckmann rearrangement of Structure 2 may depend on the particular reaction conditions employed. For example, when the rearrangement is effected with p-toluenesulfonyl chloride and sodium bicarbonate in aqueous acetone, the major products may include a lactam and Structure 4. In an embodiment, a Beckmann rearrangement of Structure 2 under anhydrous conditions leads to a product mixture comprising the 9,12- and 6,9-bridged iminoethers, Structure 3 and Structure 4. For example, when the reaction is conducted under anhydrous conditions, such as p-toluenesulfonyl chloride in pyridine, the major products may include Structure 3 and Structure 4. The ratio of products may be affected by the addition of co-solvents, temperature, and/or the initial oxime concentration. For example, increasing a proportion of pyridine as solvent, increasing the reaction temperature, and/or decreasing the initial oxime concentration may favor the formation of Structure 3 over Structure 4.
In one embodiment, a Beckmann rearrangement of Structure 2 may involve the addition of a solution of about 2.5 molar equivalents of p-toluenesulfonyl chloride in diethyl ether to a solution of Structure 2 in pyridine at a temperature in a range from about 0° C. to about 5° C. One embodiment may include oxime O-sulfonylation and subsequent rearrangement under the reaction conditions to form a mixture of Structure 3 and Structure 4.
An embodiment of the invention may include purifying products after the Beckmann rearrangement of Structure 2. For example, chromatographic methods including, but not limited to, column chromatography on silica gel or reverse phase, high-pressure liquid chromatography may be used, among other chromatographic methods. Structure 3 and Structure 4 may be separated by chromatographic methods. In another embodiment, Structure 3 may be purified by crystallization. In another embodiment, the product may be purified by a combination of crystallization and chromatography.
In some embodiments, the mixture of Structure 3 and Structure 4 may be reacted further without purification or with limited purification. In an embodiment, further reactions may be allowed to occur without isolating individual structures. For example, the mixture of isomers may be reduced without purification.
In one embodiment, Structure 3 may be isolated from the mixture using a low temperature purification procedure. For example, in one embodiment isolation of Structure 3 in dichloromethane may be carried out at a temperature between about −20° C. to about 15° C. More typically, the isolation may be carried out at a temperature of about −20° C. to about 10° C., about −10° C. to about 5° C., about −5° C. to about 5° C., or preferably about 0° C. to about 5° C. In another embodiment, the purification may be conducted below about 25° C., below about 20° C., or below about 15° C. In some embodiments, use of a low temperature purification procedure may inhibit degradation of Structure 3 to degradation products including, but not limited to Structure 5 and/or Structure 6 as depicted in FIG. 2 . In an embodiment, degradation of Structure 3 may be inhibited by removal of p-toluenesulfonic acid (hereinafter “PTSA”) from the dichloromethane phase. Some embodiments may include removing solvents from the combined organic phases under vacuum at a temperature below 35° C. An embodiment may include removing components, such as dichloromethane, with methyl tertiary butyl ether (hereinafter “MTBE”) by concentrating 1 or 2 times to a residue.
In an embodiment, Structure 3 may be formed by internal trapping of the intermediate nitrilium species by the hydroxyl group at C-12. Structure 3 may be isolated as a mixture of major and minor forms that are isomeric about the imino double bond. In an embodiment, the initial mixture of isomers may equilibrate at room temperature, both in solution or on storing as a crude product, to approximately a 1:1 mixture of isomers. In one embodiment, the first-formed, major isomer may be isolated from the mixture by crystallization from solution in a suitable solvent, such as a nitromethane solution.
In an embodiment, both forms of the isomer (i.e., Structure 3 and Structure 4) may easily be reduced to 9-deoxo-8a-aza-8a-homoerythromycin A (hereinafter “Structure 7”).
An embodiment may include a wash of the reaction mixture. In one embodiment, the wash may be done with a suitable organic solvent. Suitable organic solvents that may be used for the wash are well known in the art and include, but are not limited to, hydrocarbon solvents such as heptane, hexane, pentane, and the like. Other organic solvents include ethers such as MTBE and the like, alkyl esters such as ethyl acetate and the like, aromatic solvents such as toluene, or others. A heptane wash may remove some pyridine in the reaction mixture. In an embodiment, the resulting oil may be diluted with a second solvent mixture, such as dichloromethane and water. In an alternate embodiment, the resulting oil may be washed with 1,3-dimethyl-2-imidazolidinone or N,N′-dimethylethyleneurea (hereinafter “DMEU”). In some embodiments, the pH of the mixture may be adjusted to a value in a range from about 7 to about 12. Further some embodiments may include adjusting the pH to a value in a range from about 9 to about 10. The pH adjustment may be made using any pH modifier known in the art including, but not limited to, metal hydroxides such as aqueous sodium hydroxide, lithium hydroxide or potassium hydroxide solution. Other suitable pH adjusters include carbonate and bicarbonate salts, and amines. An embodiment may include a phase separation. Further, some embodiments may include a back wash of the aqueous phase using dichloromethane, or another suitable water immiscible solvent.
In an embodiment, pyridine in the residue may be removed during crystallization from MTBE. An embodiment may include crystallizing the product at room temperature and then cooling it to temperature within a range about −20° C. to about 15° C. or more typically about −20° C. to about 10° C. In other embodiments, the mixture is cooled to about −10° C. to about 10° C., about −5° C. to about 10° C., or about 0° C. to about 5° C. In some embodiments, the resulting material may be stirred at this temperature for a period of time to increase yield. For example, a material may be stirred for an hour or more to increase yield.
In an embodiment, Structure 3 may be isolated after filtration and a low temperature MBTE wash of the resulting yellow cake. Other chemical structures including, but not limited to Structure 4 and degradation products (e.g., Structure 5 and Structure 6—see FIG. 2 ) may remain dissolved in the mother-liquors after the rearrangement reaction. In an embodiment, Structure 3 may be stored in a solid form. Storage in a solid form may inhibit degradation.
In some embodiments, Structure 7 may be synthesized by reduction of Structure 3 with a suitable reducing agent. Various reagents that reduce iminoethers, including those of Structure 3 and 4, to the corresponding amines are known in the art (see for example “The Chemistry of Amidines and Imidates,” S. Patai (Ed.), John Wiley and Sons, 1975, pgs. 460-461 and “Comprehensive Organic Chemistry,” I. O. Sutherland (Ed.), Pergamon Press, New York, 1979, Vol. 2, pg. 495). In this regard, U.S. Pat. No. 5,985,844 describes that the reduction of cyclic imino ethers is preferably conducted with metal hydride reagents, including sodium borohydride and derivatives. However, it has been found that reduction imino ethers of Structure 3 and 4 with metal hydride reagents, including borohydride reagents, results in boron salts that complicate the isolation of the product and lead to lower yields and purity.
Therefore, in one embodiment of the invention, Structure 7 is formed by the reduction of Structure 3 using hydrogenation under conditions that provides superior quality and yield of the products. The improved hydrogenation reaction of the invention allows for a one-pot conversion of Structure 3 to a macrocycle of Structure 8 in certain embodiments. In an embodiment, Structure 7 may be formed from the mixture resulting after the rearrangement. For example, the mixture resulting from the Beckmann rearrangement of Structure 2 may be hydrogenated to form Structure 7 with a suitable pressure of hydrogen. Some embodiments may include the use of a catalyst during hydrogenation. Catalysts may include, but are not limited to, noble metals and their oxidized forms (e.g., platinum oxide), palladium based catalysts (e.g., palladium on carbon, palladium hydroxide on carbon) platinum based catalysts (e.g., platinum on carbon), rhodium based catalysts (e.g., rhodium on carbon), iridium based catalysts, ruthenium based catalysts, and/or any catalyst known or yet to be discovered in the art. In some embodiments, catalysts may be homogeneous or heterogeneous.
In an embodiment, conditions may be controlled to enhance formation of Structure 7. For example, an embodiment may include operating at room temperature, and at a hydrogen pressure of 50 bar.
In an embodiment, the hydrogenation reaction used to form Structure 7 may utilize a solvent including, but not limited to, acetic acid, formamide, acetamide, 2-pyrrolidone; polar aprotic solvents including, but not limited to, DMEU, dimethylacetamide (hereinafter “DMA”), diethylacetamide, dimethyl sulfoxide (hereinafter “DMSO”), dimethylformamide (hereinafter “DMF”), N-methylpyrrolidone (“NMP”), dioxane, tetrahydrofuran, esters such as ethyl acetate, nitriles such as acetonitrile, and hexamethylphosphorotriamide and/or other solvents known or yet to be discovered in the art.
In some embodiments, hydrogenation reactions may be carried out at a temperature in a range between about −20° C. to about 40° C. In other embodiments, the hydrogenation reaction may be conducted at a temperature of about −20° C. to about 30° C., or more typically about −20° C. to about 20° C. Preferably, the reaction is carried out at a temperature of about −10° C. to about 20° C., about −5° C. to about 20° C., about −5° C. to about 15° C., or about 5° C. to about 20° C. Controlling a temperature of the reaction may inhibit the formation of degradation products in some embodiments.
In one embodiment, Structure 7 may be synthesized directly from Structure 2. A polar aprotic solvent may be added to a mixture in the presence of a catalyst. For example, DMA may be added to Structure 7 in the presence of catalyst having 50% by weight of platinum on carbon. In some embodiments, structure 2 may be isolated from a mixture prior to the reaction. An embodiment may include reacting a mixture including Structure 2 to form Structure 7. In one embodiment, conditions in the mixture may be controlled. For example, the mixture may be stirred while maintaining a temperature of about 15° C. and a hydrogen pressure of about 50 bar.
As shown in FIG. 1 gamithromycin (hereinafter “Structure 8 (Gamithromycin)”) may be formed by reductive amination of Structure 7 in the presence of propanal and a suitable reducing agent. In one embodiment, the reductive amination reaction is carried out in the presence of hydrogen under pressure. In another embodiment, the reductive amination reaction may be carried out in the presence of a hydride reducing agent including, but not limited to a boron-based hydride reducing agent such as sodium cyanoborohydride, and the like. In another embodiment of the invention, compound of Structure 8a, wherein R is hydrogen, alkyl, alkenyl, alkynyl, aryl, heteroaryl or aralkyl. In one embodiment, a compound where R is C 1 -C 10 alkyl can be obtained by using the appropriate alkylating agent.
In yet another embodiment of the invention, R is C 1 -C 4 alkyl.
In one embodiment of the invention, the reaction may occur using a catalyst. For example, a palladium catalyst or a platinum catalyst may be used. In an embodiment, a complete reaction may occur within a few hours when using propanal in excess. Thus, utilizing propanal as both a reagent and solvent may decrease reaction time.
In an embodiment, pH may be controlled within a range from about 5.0 to about 5.5 during the reactions. One embodiment may include controlling a pH of a reaction mixture within a range from about 4.5 to about 5.5. Preferably, the pH is controlled at about 5.0 to about 5.5 prior to hydrogenation. In an embodiment, adjustments to pH may be made using acetic acid.
An embodiment may include maintaining a temperature of the reaction mixture in a range from about 20° C. to about 60° C., about 30° C. to about 50° C., or about 40° C. to about 50° C. Preferably, the temperature is about 40° C. to about 45° C.
In an embodiment, Structure 8 (Gamithromycin) may be synthesized from Structure 3 without isolating the Structure 7 intermediate. Since the reductive amination may use a catalyst similar to the catalyst used in the synthesis of Structure 7, these steps may be combined in some embodiments. Thus, one embodiment may include forming Structure 8 (Gamithromycin) without isolating the Structure 7 intermediate. In an embodiment, Structure 7 and Structure 8 (Gamithromycin) intermediates may be synthesized in a single reaction vessel without isolation. In an embodiment, this may decrease cycle time.
The invention will now be further described by way of the following non-limiting examples.
EXAMPLES
The gamithromycin was manufactured as outlined in FIG. 1 . Initially the goal was to prepare Structure 7 without the isolation of the intermediate, Structure 3. This would have maintained the same number of isolated intermediates as in the presently used process. However, the chemical instability of the Imidate-4 intermediate (Structure 3) in varying conditions resulted in degradation. The degradation products included Structure 5 and Structure 6. Varying conditions included low pH and some solvent solutions. Attempts were made to isolate Imidate-4 as a stable solid before carrying out the subsequent steps.
Example 1
Formation of Structure 3
A compound of Structure 2 (30 g) was mixed with pyridine (219.4 ml) and cooled to between 2° C. and 6° C. A solution of 4-toluenesulfonyl chloride (hereinafter “p-TsCl”) (16.5 g) in methyl t-butyl ether (64.4 ml) was added and the resulting solution was stirred for about 4 hours at between 2° C. and 6° C. and was then cooled to between −15° C. and −10° C.
Heptane (282 ml) was precooled to less than −10° C. and was added to the solution with stirring. After stirring, the phases were allowed to separate for at least 40 minutes. The upper phase (heptane phase) was removed and dichloromethane (403 ml) and water (503 ml) were added to the aqueous phase maintaining the temperature at between 0° C. and 5° C. The pH was adjusted to between 9 and 10 with sodium hydroxide solution and the mixture was stirred for at least 40 minutes at between 0° C. and 5° C. The aqueous phase was removed and backwashed twice with dichloromethane (60 ml). The combined organic phases were dried with sodium sulfate and the dried filtrate was concentrated to the residue at a temperature below 35° C. under vacuum. Methyl t-butyl ether (MTBE) and absolute ethanol were added and the mixture was concentrated to the residue again. The obtained solid was suspended in MTBE and stirred for 4 hours before cooling to between 0° C. and 5° C. The suspension was stirred for at least 1 hour before filtration and washed with MTBE (2 times with 30 ml) previously cooled to between 0° C. and 5° C. The wet solid was dried to afford a pale yellow solid (19.26 g) of Structure 3.
Example 2
Formation of Structure 7
A compound of Structure 3 (8 g) in DMA (80 ml) with catalyst Pt/C 5 % (4.0 g) was stirred at between 15° C. between 25° C. with a hydrogen pressure of 50 bar. Acetic acid addition (0.5 ml) was necessary to achieve reaction completion. Water (80 ml) was added to the suspension and the suspension was filtered through a cellulose bed. The filter cake was washed with water (80 ml) and to the resulting filtrate was added dichloromethane (160 ml) and the biphasic mixture was stirred for at least 1 hour. The organic phase was removed and dichloromethane (160 ml) was added to the aqueous phase prior to pH adjustment to between 9 and 11 with sodium hydroxide solution. The biphasic mixture was stirred and the separated organic phase containing Structure 7 was washed with water (160 ml). The obtained organic phase was dried with sodium sulfate and the dried solution was concentrated to the residue at a temperature below 50° C. under vacuum to afford an oil of Structure 7 (13.84 g).
Example 3
Formation of Structure 8 (Gamithromycin)
To the oily residue of Structure 7 (13.84 g) were added propanal (80 ml), Pd/C 3% (8.0 g) catalyst and acetic acid (7.5 ml). The suspension was stirred at a temperature between 40° C. and 45° C. with a hydrogen pressure of about 20 bar for at least 4 hours. Water (80 ml) was added to the suspension and the suspension was filtered through a cellulose bed. The filter cake was washed with water (80 ml) and to the resulting filtrate was added MTBE (160 ml) and the biphasic mixture was stirred for at least 30 minutes. The organic phase was removed and MTBE (160 ml) was added to the aqueous phase prior to pH adjustment to between 9 and 11 with sodium hydroxide solution. The biphasic mixture was stirred and the separated organic phase containing Structure 8 (Gamithromycin) was washed with water (160 ml). The obtained organic phase was dried with sodium sulfate and the dried solution was concentrated to the residue. Acetonitrile was added and the mixture was concentrated back to the crude residue of Structure 8 (Gamithromycin) (6.9 g).
Example 4
Formation of Structure 8 (Gamithromycin) without Isolation of Structure 7
A compound of Structure 3 (1 g) in DMA (10 ml) with catalyst Pt/C 5 % (0.5 g) was stirred at between 15° C. and 25° C. with a hydrogen pressure of 50 bar. Acetic acid addition (0.125 ml) was necessary to achieve reaction completion. Propanal (5 ml) and acetic acid (2.5 ml) was added to the suspension and stirred at a temperature between 40° C. and 45° C. with a hydrogen pressure of about 20 bar for at least 4 hours. Water (10 ml) was added to the suspension and the suspension was filtered through a cellulose bed. The filter cake was washed with water (10 ml) and to the resulting filtrate was added MTBE (20 ml) and the biphasic mixture was stirred for at least 30 minutes. The organic phase was removed and MTBE (20 ml) was added to the aqueous phase prior to pH adjustment to between 9 and 11 with sodium hydroxide solution. The biphasic mixture was stirred and the separated organic phase containing Structure 8 (Gamithromycin) was washed with water (20 ml). The obtained organic phase was dried with sodium sulfate and the dried solution was concentrated to the residue. Acetonitrile was added and the mixture was concentrated back to the crude residue of Structure 8 (Gamithromycin) (0.84 g).
Structure 3 was synthesized according to the current manufacturing process with a modified work-up. The process was carried out up until the heptane wash of the reaction mixture, designed to partially remove the pyridine, and the resulting oil was diluted with dichloromethane and water. The pH was then adjusted to between 9 and 10 with aqueous sodium hydroxide solution. The phases were then separated and a back wash of the aqueous phase with dichloromethane was carried out.
Isolation of Structure 3 in dichloromethane was carried out at a temperature between 0° C. to 5° C. P-Toluenesulfonic acid (hereinafter “PTSA”), from the p-toluenesulfonyl chloride reagent, remained dissolved in the aqueous phase after the phase separations.
The solvents from the combined organic phases were removed under vacuum at a temperature below 35° C. and the dichloromethane was chased with MTBE by concentrating 1 or 2 times to a residue.
The pyridine that remained in the residue was removed during crystallization from MTBE. The product was first crystallized at room temperature and then cooled to 0-5° C. and stirred at this temperature for 1 hour to increase yield.
Structure 3 was isolated after filtration and a low temperature MBTE wash of the resulting yellow cake was performed. Degradation products, Structure 5 and Structure 6, and almost all of the Structure 4 formed in the Beckmann rearrangement remained dissolved in the mother-liquors.
The yield from Structure 2 was about 65-70% by weight with a purity of the isolated Structure 3 of around 75-85% by area when utilizing HPLC. The main contaminants of Structure 3 were Structure 5 and Structure 6, each at level of 5% to 10% by area by HPLC.
FIG. 3 depicts the HPLC trace of one batch of isolated Structure 3. The peak results for FIG. 3 are shown below in Table 1.
TABLE 1
RT
Name
Area
% Area
1
12.646
23039
0.12
2
14.457
Structure 5
948922
4.82
3
15.479
Structure 3
14663001
74.43
4
17.307
625131
3.17
5
18.629
8420
0.04
6
18.821
9933
0.05
7
19.700
Structure 2
8
20.563
Structure 6
1935293
9.82
9
22.537
52241
0.27
10
23.860
5976
0.03
11
24.470
6748
0.03
12
24.848
120168
0.61
13
25.400
14
25.581
7889
0.04
15
25.990
10197
0.05
16
26.412
9086
0.05
17
27.551
46974
0.24
18
28.296
“Over Tosylation” Impurity
1094959
5.56
19
28.995
81267
0.41
20
29.549
23052
0.12
21
32.061
19794
0.10
22
33.457
8897
0.05
Sum
19700986
Although Structure 3 was unstable in solution, the solids obtained did not degrade over time, and the purity was maintained for at least 1 month.
The synthesis of Structure 7 via hydrogenation was made using a platinum oxide catalyst. The reaction mixture was stirred for about 1 day at room temperature under hydrogen at about 1000 to about 3000 psi. These conditions were the starting point for the experiments. The resulting isolated Structure 3 was used as a standard to compare products from other experiments. Other reagents/catalysts supported on carbon were also tested. Table 2 summarizes some of the results.
TABLE 2
Hydrogenation of isolated Structure 3 using several reagents/catalysts
Solvent
Reagent/Catalyst
Pressure
(quantity)
(quantity)
(bar)
Temperature
Purity
Acetic acid
PtO 2
50
r.t.
Structure 7 - 64%
(40 vol.)
(100% by weight)
Structure 6 - 23%
Acetic acid
Rh/C 5%
50
r.t.
Structure 7 - 5%
(20 vol.)
(50% by weight)
Structure 6 - 63%
Acetic acid
Pd/C 5%
50
r.t. → 50° C.
NO Structure 7 formed
(40 vol.)
(50% by weight)
Acetic acid
Pt/C 5%
50
r.t.
Structure 7 - 49%
(20 vol.)
(50% by weight)
Structure 6 - 38%
Acetic acid
Pt/C 5%
50
r.t.
Structure 7 - 29%
(40 vol.)
(66% by weight)
Structure 6 - 59%
Acetic acid
Pt/C 5% with 0.5% S
50
r.t.
Structure 7 - 59%
(40 vol.)
(66% by weight)
Structure 6 - 35%
Acetic acid
Pt/C 5%
50
r.t.
Structure 7 - 30%
(20 vol.)
(50% by weight)
Structure 6 - 70%
Acetic acid
Pt/C 1.5%
50
r.t.
Structure 7 - 45%
(20 vol.)
(75% by weight)
Structure 6 - 41%
Acetic acid
Pd/C 3%
50
r.t.
No Structure 7 formed
(20 vol.)
(50% by weight)
Acetic acid
Pt/C 5%
50
r.t.
Structure 7 - 31%
(20 vol.)
(50% by weight)
Structure 6 - 52%
Acetic acid
Pt/C 5%
50
r.t.
Structure 7 - 39%
(20 vol.)
(50% by weight)
Structure 6 - 45%
Acetic acid
Pt/C 5%
50
r.t.
Structure 7 - 50%
(20 vol.)
(50% by weight)
Structure 6 - 23%
In the trials conducted, the catalyst Pt/C 5 % provided a desired result for the conditions utilized. FIG. 4 presents the HPLC trace of Structure 7 obtained from a trial using the Pt/C 5 % catalyst. The values of the area under the peak on the HPLC trace are shown in Table 3 below.
TABLE 3
RT
Name
Area
% Area
1
15.500
Structure 3
2
16.302
45449
0.41
3
16.516
43684
0.40
4
17.243
73435
0.67
5
17.575
24360
0.22
6
18.628
129219
1.18
7
19.700
Structure 2
8
19.729
11809
0.11
9
20.414
Structure 6
2536368
23.10
10
21.409
1189347
10.83
11
23.889
47595
0.43
12
24.300
28497
0.26
13
24.508
Structure 7
5505606
50.15
14
25.341
20326
0.19
15
26.023
170383
1.55
16
26.374
4586
0.04
17
27.475
12623
0.11
18
27.983
11830
0.11
19
29.262
15805
0.14
20
29.952
32113
0.29
21
31.332
35383
0.32
22
32.221
109461
1.00
23
32.733
51617
0.47
24
32.993
433397
3.95
25
34.142
7096
0.06
26
35.351
406681
3.70
27
36.795
10093
0.09
28
43.278
22005
0.20
Sum
10978866
The use of platinum oxide also gave a desired result.
The standard conditions used to carry out the hydrogenation were: 20 volumes of acetic acid; room temperature; 50 bar hydrogen; and an overnight stir were used in almost all of the laboratory trials. From the survey of catalysts platinum appeared to be the ideal noble metal for this reaction.
All of the tests in this initial study gave Structure 7 with a considerable amount of Structure 6. Stability data showed that when a solution of Structure 3 when stirred with 20 volumes of acetic acid at room temperature, Structure 3 was completely degraded to Structure 5 and Structure 6 after a few hours. Since these conditions were used in the hydrogenation, it was concluded that degradation of Structure 3 due to the acidic conditions was competing with the formation of Structure 7.
Hence, the reaction was tried in DMEU instead of acetic acid. The results were surprising, the reaction was cleaner with only a small amount of Structure 6 formed and the reaction rate was similar to the reactions carried out using acetic acid as a solvent.
Other solvents with characteristics similar to the DMEU, such as DMF and DMA were then tested. Tests showed that Structure 3 was unchanged in a solution of DMEU, DMF or DMA at a temperature of about 5° C. for 3-4 hours, and with only a small amount of degradation at room temperature after 1 day of stirring.
Table 4 summarizes the results of the hydrogenations carried out using these solvents and the conditions.
TABLE 4
Hydrogenation of isolated Structure 3 using DMEU, DMF and DMA
Solvent
Reagent/Catalyst
Pressure
(quantity)
(quantity)
(bar)
Temperature
Purity
DMEU (20 vol.)
Pt/C 5%
50
5° C. → r.t.
Structure 7 - 90%
(50% BY WEIGHT)
Structure 6 - 1.4%
DMF (20 vol.)
Pt/C 5%
50
5-10° C.
Structure 7 - 85%
(50% BY WEIGHT)
Structure 6 - 3.8%
DMA (20 vol.)
Pt/C 5%
50
5-10° C.
Structure 7 - 86.5%
(50% BY WEIGHT)
Structure 6 - 1.6%
DMA (10 vol.)
Pt/C 5%
50
5-20° C.
Structure 7 - 87%
(25% BY WEIGHT)
Structure 6 - 3.5%
DMA (10 vol.)
Pt/C 5%
50
15-20° C.
Structure 7 - 87%
(50% BY WEIGHT)
Structure 6 - 1.4%
The hydrogenations were carried out at a temperature between 5° C. and 20° C. In some reactions, acetic acid (0.25-0.5 volumes) was added toward the end of the reaction. The total solvent volume was reduced from 20 volumes to 10 volumes while a reduction in the quantity of the platinum catalyst was made without affecting the reaction performance significantly.
DMA was the solvent chosen. The work-up was as follows:
The reaction mixture was passed through a cellulose filter. The reactor was rinsed with water. The rinsed water was used to wash the cellulose plug. Dichloromethane was added to the filtrate and the pH of the mixture was adjusted to between 4.5 and 5.5 with acetic acid, if necessary, before phase separation. Dichloromethane was added to the aqueous phase and the pH was adjusted to between 9 and 11 with aqueous sodium hydroxide solution. The resulting organic phase containing the product was washed with water to remove some DMA still present and then concentrated to afford a white foam.
FIG. 5 depicts the HPLC trace of Structure 7 obtained from another laboratory trial utilizing 10 volumes of DMA and the platinum catalyst. The values of the area under the peak on the HPLC trace are shown in Table 5 below.
TABLE 5
RT
RRT
Name
Area
% Area
1
4.482
0.233
60529
0.58
2
6.249
0.324
29113
0.28
3
7.457
0.387
26836
0.26
4
12.721
0.660
6900
0.07
5
15.188
0.789
18851
0.18
6
15.513
0.805
16914
0.16
7
16.442
0.854
Structure 3
10800
0.10
8
17.827
0.926
12612
0.12
9
18.129
0.941
30191
0.29
10
18.503
0.961
11329
0.11
11
19.262
1.000
Structure 2
7558
0.07
12
20.725
1.076
8729
0.08
13
21.093
1.095
Structure 6
142158
1.36
14
21.800
1.132
4515
0.04
15
22.080
1.146
34763
0.33
16
24.460
1.270
7392
0.07
17
25.010
1.298
Structure 7
9089710
86.99
18
26.733
1.388
49639
0.48
19
28.061
1.457
16743
0.16
20
28.565
1.483
14803
0.14
21
28.880
1.499
26345
0.25
22
29.673
1.541
12139
0.12
23
29.883
1.551
1998
0.02
24
30.942
1.606
47982
0.46
25
31.848
1.653
2627
0.03
26
34.104
1.771
88091
0.84
27
35.821
1.860
512336
4.90
28
41.144
2.136
19501
0.19
29
42.567
2.210
3945
0.04
30
42.929
2.229
62709
0.60
31
46.935
2.437
71390
0.68
Sum
1044918
An attempt was made to synthesize Structure 7 directly from the Z-oxime. The same work-up procedure as described above was applied but instead of isolating the Structure 3 by addition of MTBE, 10 volumes of DMA and 50% by weight of Pt/C 5 % catalyst were added. The resulting mixture was stirred at a temperature of about 15° C. under 50 bar hydrogen pressure. The reaction proceeded as expected but an oil was obtained with a mixture of Structure 7 with about 40% by area by HPLC together with Structure 4 with about 42% by area by HPLC.
Since Structure 4 was not removed by crystallization and Structure 3 was not isolated, it was carried through to the isolated Structure 7. The presence of Structure 4 in the hydrogenation may have had an influence on the impurity profile obtained, although it seemed to be inert in the hydrogenation conditions. Residual pyridine, which was not removed because Structure 3 was not isolated, also influenced the quality of the Structure 7 obtained.
Structure 8 (Gamithromycin) was prepared by carrying out a reductive amination of Structure 7 in the presence of propanal. This reaction was carried out under catalytic conditions using hydrogen and a palladium catalyst. Several palladium catalysts and a smaller amount of platinum catalysts were screened in this transformation. With about 10 equivalents of propanal in ethanol the reactions were slow and incomplete. Using propanal in a large excess allowed for a complete reaction within a few hours. The propanal acted as both reagent and solvent.
Attempts using an acetate buffer solution to achieve a pH of 5.0 to 5.5 were made. However, it was subsequently established that the pH of the reaction mixture needs only to be set to between 5.0 and 5.5 with acetic acid before hydrogenation.
Table 6 summarizes some of the results and conditions for the synthesis of Structure 8 (Gamithromycin).
TABLE 6
Results and conditions of the reductive animation of Structure 7
Solvent
Reagent/Catalyst
Pressure
Initial
(quantity)
(quantity)
(bar)
pH
Temperature
Purity
Propanal
Pd/C 5%
20
4.70
40-45° C.
Structure 8
(10 vol.)
(100% by weight)
(Gamithromycin) - 42%
Propanal
Pd/C 3%
20
5.23
40-45° C.
Structure 8
(10 vol.)
(100% by weight)
(Gamithromycin) - 96%
Propanal
Pt/C 5% with 0.5% S
10
5.06
40-45° C.
Structure 8
(10 vol.)
(50% by weight)
(Gamithromycin) - 46%
Structure 7 - 12%
Propanal
Pt/C 5%
20
—
40-45° C.
Structure 8
(20 vol.)
(100% by weight)
(Gamithromycin) - 88%
Propanal
Pd/C 3%
20
5.49
40-45° C.
Structure 8
(10 vol.)
(100% by weight)
(Gamithromycin) - 89%
Initial tests indicated that hydrogenation at room temperature had a slow rate of reaction. As a result, a temperature range of 40-45° C. was used for almost all reactions. The pH of the reaction mixture fell to a range of about 4.0 to about 4.5 during the hydrogenation.
Structure 8 (Gamithromycin) was obtained after work-up as described above but using MTBE as the extracting solvent. The yields depended significantly on the quality of the Structure 7 synthesized and on the scale of the laboratory experiment. Structure 8
(Gamithromycin) was obtained with a yield of 86% by weight from 8 g of isolated Structure 3. FIG. 6 depicts the HPLC trace of a typical isolated Structure 8 (Gamithromycin). The values of the area under the peak on the HPLC trace are shown in Table 7 below.
TABLE 7
RT
RRT
Name
Area
% Area
1
8.255
0.242
7309
0.05
2
11.717
0.343
3245
0.02
3
15.434
0.452
2903
0.02
4
18.081
0.529
16167
0.11
5
19.218
0.562
4256
0.03
6
20.235
0.592
11132
0.07
7
21.027
0.615
1696
0.01
8
22.003
0.644
1388
0.01
9
22.797
0.667
1366
0.01
10
23.200
0.679
2027
0.01
11
23.938
0.700
2338
0.02
12
24.327
0.712
23838
0.16
13
24.725
0.723
4942
0.03
14
25.457
0.745
3033
0.02
15
26.469
0.774
20898
0.14
16
26.753
0.783
40372
0.27
17
27.407
0.802
10260
0.07
18
28.108
0.822
4246
0.03
19
28.420
0.832
1291
0.01
20
29.200
0.854
11826
0.08
21
29.310
0.858
29056
0.19
22
29.847
0.873
15468
0.10
23
30.303
0.887
4789
0.03
24
30.767
0.900
7826
0.05
25
31.215
0.913
10291
0.07
26
31.717
0.928
813
0.01
27
31.931
0.934
18022
0.12
28
32.319
0.946
2588
0.02
29
32.590
0.954
8105
0.05
30
33.093
0.968
70110
0.47
31
33.504
0.980
1750
0.01
32
34.176
1.000
Structure 8
13341092
88.88
33
35.049
1.026
21138
0.14
34
35.614
1.042
13337
0.09
35
36.615
1.071
457
0.00
36
37.041
1.084
57533
0.38
37
38.514
1.127
92101
0.61
38
39.107
1.144
8684
0.06
39
39.687
1.161
63300
0.42
40
40.935
1.198
400243
2.67
41
41.533
1.215
3963
0.03
42
41.750
1.222
3210
0.02
43
42.100
1.232
807
0.01
44
42.794
1.252
116557
0.78
45
43.002
1.258
242434
1.62
46
43.283
1.266
6321
0.04
47
45.183
1.322
103524
0.69
48
45.904
1.343
150603
1.00
49
46.942
1.374
37328
0.25
50
48.367
1.415
4688
0.03
Sum
15010670
Since the reductive amination was carried out using a platinum catalyst, it was possible to test the use of the same platinum catalyst for the synthesis of Structure 8 (Gamithromycin) from Structure 3 without isolating Structure 7.
In one laboratory trial Structure 7 was synthesized from isolated Structure 3 using 10 volumes of DMA as a solvent and 50% by weight of Pt/C 5 % as described above. After complete reaction to form Structure 7, which was not isolated, 5 volumes of propanal were added and the pH was adjusted to about 5.4 with acetic acid and hydrogenation was carried out as before in the conditions described above.
Structure 7 was converted into Structure 8 (Gamithromycin), the residual DMA had no detrimental affect. Both hydrogenation reactions proceeded, as expected, with similar conversion rates to reactions starting from isolated intermediates.
After the work-up as described above, Structure 8 (Gamithromycin) was obtained with a yield of 84% by weight from Structure 3. Although the yield was comparable with the laboratory trial where Structure 7 was isolated, the purity was lower (78% by area when measured utilizing HPLC).
Several laboratory batches of Structure 8 (gamithromycin) were crystallized to form isolated gamithromycin (Structure 8) having a yield of about 70-80% by weight and a purity usually above 98% by area when measured utilizing HPLC. FIG. 7 depicts the HPLC trace of one of those batches of Structure 8 (Gamithromycin). The values of the area under the peak on the HPLC trace are shown in Table 8 below.
TABLE 8
RT
RRT
Name
Area
% Area
1
20.149
0.591
16944
0.14
2
26.620
0.780
6928
0.06
3
27.269
0.799
2124
0.02
4
29.192
0.856
21806
0.18
5
29.723
0.871
19650
0.17
6
34.108
1.000
Structure 8
11629284
98.19
7
35.463
1.040
10530
0.09
8
37.073
1.087
46419
0.39
9
42.781
1.254
89503
0.76
Sum
11843187
In FIG. 8 this HPLC trace was overlaid with a Structure 8 (Gamithromycin) trace from conventional production. From a comparison of the two HPLC profiles, the formation of new impurities was not observed. Hence, this new process can be applied giving Structure 8 (Gamithromycin) with a similar impurity profile to that of the current manufacturing process.
Having thus described in detail various embodiments of the present invention, it is to be understood that the invention defined by the above paragraphs is not to be limited to particular details set forth in the above description as many apparent variations thereof are possible without departing from the spirit or scope of the present invention. | The present invention relates to methods for synthesizing macrolide compounds which are known to have antibacterial activity, and are useful in the therapy of bacterial infections in mammals. More specifically, the invention relates to methods for synthesizing the macrolide antibiotic, gamithromycin utilizing a novel configuration of catalysts, chemical structures, and/or methods. An embodiment of the present invention may include allowing multiple chemical reactions to proceed without the isolation of chemical intermediates. Thus, multiple reactions may occur in one reaction vessel allowing for a considerable decrease in the cycle-time. The present invention also provides a novel method for inhibiting degradation while isolating a structure of a pharmaceutical composition. | 2 |
BACKGROUND OF THE DISCLOSURE
[0001] 1. Field of the Invention
[0002] Embodiments of the invention generally provide a substrate support utilized in semiconductor processing and a method of fabricating the same.
[0003] 2. Description of the Background Art
[0004] Liquid crystal displays or flat panels are commonly used for active matrix displays such as computer and television monitors. Generally, flat panels comprise two glass plates having a layer of liquid crystal material sandwiched therebetween. At least one of the glass plates includes at least one conductive film disposed thereon that is coupled to a power supply. Power supplied to the conductive film from the power supply changes the orientation of the crystal material, creating a pattern such as text or graphics seen on the display. One fabrication process frequently used to produce flat panels is plasma enhanced chemical vapor deposition (PECVD).
[0005] Plasma enhanced chemical vapor deposition is generally employed to deposit thin films on a substrate such as a flat panel or semiconductor wafer. Plasma enhanced chemical vapor deposition is generally accomplished by introducing a precursor gas into a vacuum chamber that contains a substrate. The precursor gas is typically directed through a distribution plate situated near the top of the chamber. The precursor gas in the chamber is energized (e.g., excited) into a plasma by applying RF power to the chamber from one or more RF sources coupled to the chamber. The excited gas reacts to form a layer of material on a surface of the substrate that is positioned on a temperature controlled substrate support. In applications where the substrate receives a layer of low temperature polysilicon, the substrate support may be heated in excess of 400 degrees Celsius. Volatile by-products produced during the reaction are pumped from the chamber through an exhaust system.
[0006] Generally, the substrate support utilized to process flat panel displays are large, often exceeding 550 mm×650 mm. The substrate supports for high temperature use typically are casted, encapsulating one or more heating elements and thermocouples in an aluminum body. Due to the size of the substrate support, one or more reinforcing members are generally disposed within the substrate support to improve the substrate support's stiffness and performance at elevated operating temperatures (i.e., in excess of 350 degrees Celsius and approaching 500 degrees Celsius). Although substrate supports configured in this manner have demonstrated good processing performance, manufacturing supports has proven difficult.
[0007] One problem in providing a robust substrate support is that the reinforcing member may occasionally displace, deform and sometimes break during the casting process. The reinforcing member typically includes portions that are unsupported in the pre-cast state of the substrate support. After assembling the reinforcing member, the heating elements and thermocouples into a subassembly, the subassembly is supported in a mold and encapsulated with molten aluminum. Conventional presses used in the casting process typically have one or twin rams that provide up to about 500 tons of pressure that works not whole area of cast surface but local area flowing the molten aluminum around the subassembly disposed in the substrate support mold. In this case, there is always nonuniformity of pressure working on the molten aluminum. Occasionally, this nonuniformity of the weight and pressure of the aluminum flowing in the mold during the casting process causes the reinforcing member to displacement, deformation and sometimes fracture. Additionally, this casting process results in undesirable heterogeneous grain size of aluminum cast. Furthermore, such pressures stress the substrate support up to about 28 MPa, which is not enough to get a desired uniform micro-grain size within the aluminum cast.
[0008] Another problem with substrate support formed using this molding process is the lack of integrity of the aluminum where the flow of molten aluminum comes back together on the side of the substrate support furthest from the molten aluminum source. As a substantial amount of aluminum and time is needed to encapsulate the heating elements, thermocouples and reinforcing members, the flow of aluminum may cool causing a seam to be created where the leading edges of the aluminum flow merges under the subassembly at less than acceptable temperatures.
[0009] Depending on the temperature of the aluminum when the seam is formed, the seam may become a source of a variety of defects. For example, vacuum leaks may propagate through the seam between the interior of the chamber and the environment surrounding the chamber. Vacuum leakage may degrade process performance and may lead to poor heater performance that contributes to pre-mature heater failure. Moreover, thermal cycling of the substrate support may cause the substrate support to fracture along the seam, thereby causing failure and possible release of particulates into the chamber environment.
[0010] As the cost of materials and manufacturing the substrate support is great, failure of the substrate support is highly undesirable. Additionally, if the substrate support fails during processing, a substrate supported thereon may be damaged. This can occur after a substantial number of processing steps have been preformed thereon, thus resulting in the expensive loss of the substrate support. Moreover, replacing a damaged support in the process chamber creates a costly loss of substrate throughput while the process chamber is idled during replacement or repair of the substrate support. Moreover, as the size of the next generation substrate supports are increased to accommodate substrates in excess of 1.44 square meters at operating temperatures approaching 500 degrees Celsius, the aforementioned problems become increasingly important to resolve.
[0011] Therefore, there is a need for an improved substrate support.
SUMMARY OF THE INVENTION
[0012] Generally, a substrate support and method of fabricating the same are provided. In one embodiment, a method of fabricating a substrate support includes the steps of assembling a subassembly comprising a first reinforcing member and a heating element, supporting the subassembly at least 40 mm from a bottom of a mold, encapsulating the supported subassembly with molten aluminum, and applying pressure to the molten aluminum.
[0013] In another embodiment, a method of fabricating a substrate support includes the steps of a method of fabrication includes assembling a subassembly comprising a stud disposed through a heating element sandwiched between a first reinforcing member and a second reinforcing member, supporting the subassembly above a bottom of a mold, encapsulating the subassembly disposed in the mold with molten aluminum to form a casting, forming a hole in the casting by removing at least a portion of the stud, and disposing a plug in at least a portion of the hole.
[0014] In another aspect of the invention, a substrate support is provided. In one embodiment, the substrate support includes at least a first reinforcing member and a heating element disposed within a cast aluminum body. At least one hole is formed in the aluminum body between an outer surface and at least the heating element or the reinforcing member. A plug is disposed in the hole between the outer surface and the heating element or the reinforcing member. In another embodiment, the hole houses a stud during casting that maintains the heating element and the reinforcing member in a spaced-apart relation and is at least partially removed from the hole before insertion of the plug.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The teachings of the present invention can be readily understood by considering the following detailed description in conjunction with the accompanying drawings, in which:
[0016] [0016]FIG. 1 depicts a schematic sectional view of one embodiment of a processing chamber having a substrate support of the present invention;
[0017] [0017]FIG. 2 is one embodiment of a method of fabricating a substrate support;
[0018] [0018]FIG. 3A is a sectional view of one embodiment of a subassembly;
[0019] [0019]FIG. 3B is a plan view of the subassembly of FIG. 3A;
[0020] [0020]FIG. 4 is a schematic of the subassembly of FIG. 3A disposed in a press; and
[0021] [0021]FIG. 5 is a sectional view of an embodiment of a substrate support.
[0022] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures.
DETAILED DESCRIPTION
[0023] The invention generally provides a substrate support and methods of fabricating a substrate support. The invention is illustratively described below in reference to a plasma enhanced chemical vapor deposition system, such as a plasma enhanced chemical vapor deposition (PECVD) system, available from AKT, a division of Applied Materials, Inc., Santa Clara, Calif. However, it should be understood that the invention has utility in other system configurations such as physical vapor deposition systems, ion implant systems, etch systems, other chemical vapor deposition systems and any other system in which processing a substrate on a substrate support is desired.
[0024] [0024]FIG. 1 is a cross sectional view of one embodiment of a plasma enhanced chemical vapor deposition system 100 . The system 100 generally includes a chamber 102 coupled to a gas source 104 . The chamber 102 has walls 106 , a bottom 108 and a lid assembly 110 that define a process volume 112 . The process volume 112 is typically accessed through a port (not shown) in the walls 106 that facilitates movement of the substrate 140 into and out of the chamber 102 . The walls 106 and bottom 108 are typically fabricated from a unitary block of aluminum or other material compatible for processing. The lid assembly 110 contains a pumping plenum 114 that couples the process volume 112 to an exhaust port (that includes various pumping components, not shown).
[0025] The lid assembly 110 is supported by the walls 106 and can be removed to service the chamber 102 . The lid assembly 110 is generally comprised of aluminum. A distribution plate 118 is coupled to an interior side 120 of the lid assembly 110 . The distribution plate 118 is typically fabricated from aluminum. The center section includes a perforated area through which process and other gases supplied from the gas source 104 are delivered to the process volume 112 . The perforated area of the distribution plate 118 is configured to provide uniform distribution of gases passing through the distribution plate 118 into the chamber 102 .
[0026] A heated substrate support assembly 138 is centrally disposed within the chamber 102 . The support assembly 138 supports a substrate 140 during processing. In one embodiment, the substrate support assembly 138 comprises an aluminum body 124 that encapsulates at least one embedded heating element 132 and a thermocouple 190 . At least a first reinforcing member 116 is generally embedded in the body 124 proximate the heating element 132 . A second reinforcing member 166 may be disposed within the body 124 on the side of the heating element 132 opposite the first reinforcing member 116 . The reinforcing members 116 and 166 may be comprised of metal, ceramic or other stiffening materials. In one embodiment, the reinforcing members 116 and 166 are comprised of aluminum oxide fibers. Alternatively, the reinforcing members 116 and 166 may be comprised of aluminum oxide fiber combined with aluminum oxide particles, silicon carbide fiber, silicon oxide fiber or similar materials. The reinforcing members 116 and 166 may include loose material or may be a pre-fabricated shape such as a plate. Alternatively, the reinforcing members 116 and 166 may comprise other shapes and geometry. Generally, the reinforcing members 116 and 166 have some porosity that allows aluminum to impregnate the members 116 , 166 during a casting process described below.
[0027] The heating element 132 , such as an electrode disposed in the support assembly 138 , is coupled to a power source 130 and controllably heats the support assembly 138 and substrate 140 positioned thereon to a predetermined temperature. Typically, the heating element 132 maintains the substrate 140 at a uniform temperature of about 150 to at least about 460 degrees Celsius.
[0028] Generally, the support assembly 138 has a lower side 126 and an upper side 134 that supports the substrate. The lower side 126 has a stem cover 144 coupled thereto. The stem cover 144 generally is an aluminum ring coupled to the support assembly 138 that provides a mounting surface for the attachment of a stem 142 thereto.
[0029] Generally, the stem 142 extends from the stem cover 144 and couples the support assembly 138 to a lift system (not shown) that moves the support assembly 138 between an elevated position (as shown) and a lowered position. A bellows 146 provides a vacuum seal between the chamber volume 112 and the atmosphere outside the chamber 102 while facilitating the movement of the support assembly 138 . The stem 142 additionally provides a conduit for electrical and thermocouple leads between the support assembly 138 and other components of the system 100 .
[0030] The support assembly 138 generally is grounded such that RF power supplied by a power source 122 to the distribution plate 118 (or other electrode positioned within or near the lid assembly of the chamber) may excite the gases disposed in the process volume 112 between the support assembly 138 and the distribution plate 118 . The RF power from the power source 122 is generally selected commensurate with the size of the substrate to drive the chemical vapor deposition process.
[0031] The support assembly 138 additionally supports a circumscribing shadow frame 148 . Generally, the shadow frame 148 prevents deposition at the edge of the substrate 140 and support assembly 138 so that the substrate does not stick to the support assembly 138 .
[0032] The support assembly 138 has a plurality of holes 128 disposed therethrough that accept a plurality of lift pins 150 . The lift pins 150 are typically comprised of ceramic or anodized aluminum. Generally, the lift pins 150 have first ends 160 that are substantially flush with or slightly recessed from a upper side 134 of the support assembly 138 when the lift pins 150 are in a normal position (i.e., retracted relative to the support assembly 138 ). The first ends 160 are generally flared to prevent the lift pins 150 from falling through the holes 128 . Additionally, the lift pins 150 have a second end 164 that extends beyond the lower side 126 of the support assembly 138 . The lift pins 150 may be actuated relative to the support assembly 138 by a lift plate 154 to project from the support surface 130 , thereby placing the substrate in a spaced-apart relation to the support assembly 138 .
[0033] The lift plate 154 is disposed proximate the lower side 126 of the support surface. The lift plate 154 is connected to the actuator by a collar 156 that circumscribes a portion of the stem 142 . The bellows 146 includes an upper portion 168 and a lower portion 170 that allow the stem 142 and collar 156 to move independently while maintaining the isolation of the process volume 112 from the environment exterior to the chamber 102 . Generally, the lift plate 154 is actuated to cause the lift pins 150 to extend from the upper side 134 as the support assembly 138 and the lift plate 154 move closer together relative to one another.
[0034] [0034]FIG. 2 depicts a flow chart of one embodiment of a method 200 for fabricating the support assembly 138 . Generally, the method 200 begins at step 202 of assembling a subassembly that includes the reinforcing members 116 , 166 , the heating element 132 and the thermocouple 190 . At step 204 and step 206 , the subassembly 300 is supported in a mold that is disposed in a press and respectively encapsulated with aluminum to form a casting. At step 208 , the casting is processed to form an unfinished substrate support. At step 210 , the unfinished substrate support is finished by anodizing the substrate support assembly 138 and coupling the heating elements 132 to the appropriate electrical connections, for example, soldering lead wires to the heating elements 132 .
[0035] [0035]FIG. 3A depicts one embodiment of a subassembly 300 assembled at step 202 . The subassembly 300 generally includes the first reinforcing member 116 , the second reinforcing member 166 , the heating element 132 and the thermocouple 190 . A plurality of studs 302 , for example, fasteners, pins, rods, bolts and the like comprised of a ceramic or metallic material such as stainless steel, are utilized to support and maintain a predetermined spacing between the reinforcing members 116 , 166 , the heating element 132 and the thermocouple 190 . The studs 302 vary in number and be arranged in different patterns, for example, a grid comprising 12 equally spaced studs 302 (see FIG. 3B). The studs 302 generally are passed through the first reinforcing member 116 and configured to support the first reinforcing member 116 at least 40 mm from an end 304 of the stud 302 . In one embodiment, the position of the first reinforcing member 116 relative to the end 304 of the studs 302 is maintained by providing a first ledge 306 in the stud 302 on which the first reinforcing member 116 rests. Optionally, the stud 302 may incorporate other features or devices such as standoffs, threads, tapers and the like to maintain the relative positions of the studs 302 and the first reinforcing member 116 .
[0036] The heating elements 132 and the thermocouples 190 are disposed on the studs 302 proximate the first reinforcing member 116 from the side of the stud 302 opposite the end 304 . The heating elements 132 and the thermocouple 190 are generally disposed against the first reinforcing member 116 but may be maintained in a spaced-apart relation to the first reinforcing member 116 . In one embodiment, a spaced-apart relation is maintained by resting the heating elements 132 and the thermocouple 190 on a second ledge 308 of the stud 302 . Alternatively, threads, standoffs, spacers or geometry such as bosses incorporated into one or both of the heating elements 132 , the thermocouple 190 and first reinforcing member 116 may be used to maintain the relative spacing therebetween.
[0037] The second reinforcing member 166 is disposed on the stud 302 proximate the heating element 132 . Generally, the second reinforcing member 166 is disposed against the heating element 132 but may optionally be maintained in a spaced-apart relation by providing a third ledge 310 on which the second reinforcing member 166 rests. The spacing between the heating elements 132 and the second reinforcing member 166 may alternatively be maintained as described above.
[0038] The subassembly 300 may optionally be secured to prevent movement between the first reinforcing member 116 , the second reinforcing member 166 , the heating element 132 and the thermocouple 190 during casting. In one embodiment, the first reinforcing member 116 is retained against the first ledge 306 by a metallic collar 312 pressed on at least some of the studs 302 . The second reinforcing member 166 is retained against the third ledge by another collar 312 while the heating element 132 and the thermocouple 190 are respectively retained against the second ledge 308 by another collar 312 . The collars 312 are preferably fabricated from stainless steel. Alternatively, the subassembly 300 may be secured on the studs 302 by other devices such as nuts (with threaded studs), adhesives, friction on the studs (i.e., press or snap fit), wire, ceramic string, twine and the like. Optionally, the first reinforcing member 116 , the second reinforcing member 166 , the heating element 132 and the thermocouple 190 may include interlocking geometry integral to the subassembly such as mating pins and bosses, standoffs, press and snap fits and the like.
[0039] Optionally, the studs 302 may be coupled at their end 304 to a base plate 314 . The base plate 314 is typically comprised of a metallic material and is utilized to position the subassembly 300 in a predetermined position in the mold 400 . In one embodiment, the base plate 314 is a perforated steel plate having a plurality of threaded holes to accept the studs 302 . The thickness of base plate 314 is at least 40 mm to prevent a deformation during the casting.
[0040] [0040]FIG. 4 depicts a schematic of one embodiment of the subassembly 300 disposed in the mold 400 which is disposed in the press 404 . Generally, the subassembly 300 is positioned within the mold 400 such that the subassembly is supported from a bottom 402 of the mold 400 by at least 40 mm at step 204 . The back plate 314 that is coupled to the subassembly 300 typically rests in a predetermined bottom 402 of the mold 400 . The back plate 314 may be located relative the mold 400 in the predetermined position by dowel pins, geometric interfacing and the like. By maintaining the subassembly 300 in this position, adequate encapsulation around all sides of the subassembly 300 is ensured.
[0041] Alternatively, the subassembly 300 may be supported in the mold 400 in other ways. For example, mold pins (not shown) may project from the bottom 402 of the mold 400 and support the subassembly 300 . In another configuration, one or more members (not shown) may extend between other portions of the mold 400 to support the subassembly 300 . The studs 302 may be directly disposed on or in locating holes in mold bottom 402 while maintaining at least 40 mm between the first reinforcing plate 116 and the mold bottom 402 on subassemblies 300 that do not include the back plate 314 .
[0042] The mold 400 is generally heated to minimize the cooling of the molten aluminum used to encapsulate the subassembly. The mold 400 may be heated through any conventional means including circulated fluids, resistance heaters and burners. Generally, the mold 400 is heated to a temperature between about 300 and about 350 degrees Celsius.
[0043] The molten aluminum at about 800 to about 900 degrees Celsius is generally dispensed into the mold in a single shot at step 206 . The single shot minimizes seam formation at the interface between shots due to cooling of the aluminum that occurs during utilizing conventional processes. The aluminum may be dispensed manually or automatically through an opening in the top of the mold or one or more other passages (not shown). Generally, aluminum alloy 6061 is utilized but other alloys may be substituted.
[0044] Once the molten aluminum is in the mold, pressure is applied to the aluminum to assist the aluminum in flowing around and in between the components of the subassembly 300 . The applied pressure additionally impregnates the reinforcing members 116 and 166 with aluminum. In one embodiment, a single ram 406 of the press 404 applies pressure to an area 408 of the molten aluminum above the subassembly 300 . Generally, the area 408 is at least as large as the area of the subassembly 300 and may include the entire width of the mold 400 . The pressure applied by the ram 406 is generally less than about 3,000 tons. The space between the support assembly 138 and the bottom 402 of the mold 400 or the base plate 314 enhances the flow the aluminum therebetween. Optionally, the mold 400 may include a vacuum applied to the mold's vents (not shown) to assist the flow of aluminum. The use of a single ram 406 over a large area 408 results in uniformity application of stress, preferably in excess of about 40 MPa, to the entire area of the support assembly 138 , which eliminates the displacement, deformation and fracture of the reinforcing members 116 , 166 . The high stress correspondingly increases the homogeneity of grain size of aluminum cast and decreases the integrity of any seams or flow lines that may form during casting.
[0045] [0045]FIG. 5 depicts one embodiment of the substrate support assembly 138 in the form of a post-molding casting 500 . Generally, the casting 500 is processed at steps 206 to form an unfinished processing support. In one embodiment, the processing step 208 generally includes annealing the casting 500 to relieve residual stresses in the casting 500 . In one embodiment, the casting 500 is annealed at about 510 to about 520 degrees Celsius for about 2 to about 3 hours.
[0046] Next, the casting is machined to roughly the dimensions of the finished substrate support assembly 138 . The studs 302 are at least partially removed from the bottom side and replaced with an aluminum plug 502 that is welded to the substrate support assembly 138 . The stem cover 144 is then welded to the substrate support assembly 138 . The support assembly 138 is annealed once more before a final machining step that brings the substrate support 138 to its final dimensions. Electrical leads are then attached to the heating element 132 and fed through the stem 142 which is then welded to the stem cover 144 .
[0047] The surface of the support assembly 138 is then treated to remove tool marks left by the machining operations. The step of removing the tool marks may optionally be completely or partially performed before the second anneal step. The surface treatments may include grinding, electropolishing, abrasive or bead blasting, chemical etching and the like. In one embodiment, the substrate support is treated by blasting the substrate support with aluminum oxide balls and exposing the support to an alkaline or acid etchant. At step 210 , the substrate support 138 is anodized to provide a protective finish to the substrate support.
[0048] Although several preferred embodiments which incorporate the teachings of the present invention have been shown and described in detail, those skilled in the art can readily devise many other varied embodiments that still incorporate these teachings. | A substrate support and method of fabricating the same are provided. Generally, one method of fabrication includes assembling a subassembly comprising a first reinforcing member and a heating element, supporting the subassembly at least 40 mm from a bottom of a mold, encapsulating the supported subassembly with molten aluminum, and applying pressure to the molten aluminum. Alternatively, a method of fabrication includes assembling a subassembly comprising a stud disposed through a heating element sandwiched between a first reinforcing member and a second reinforcing member, supporting the subassembly above a bottom of a mold, encapsulating the subassembly disposed in the mold with molten aluminum to form a casting, forming a hole in the casting by removing at least a portion of the stud, and disposing a plug in at least a portion of the hole. | 1 |
TECHNICAL FIELD
[0001] The present invention relates to L-proline cis-4-hydroxylase enzyme, a production method of cis-4-hydroxy-L-proline using the enzyme, a recombinant vector containing a polynucleotide encoding the aforementioned enzyme, and a transformant containing the recombinant vector.
BACKGROUND ART
[0002] Hydroxy-L-proline is one kind of modified amino acids having a structure wherein a hydroxyl group is introduced into L-proline. It has 4 kinds of isomers due to the difference in the site into which the hydroxyl group is introduced (the 3-position or the 4-position carbon atom), and the difference in the spatial configuration of the hydroxyl group (trans configuration or cis configuration). Among the isomers of hydroxyproline, cis-4-hydroxy-L-proline is a substance useful as a starting material of a synthetic intermediate for pharmaceutical products such as carbapenem antibiotic, N-acetylhydroxyproline utilized as an anti-inflammatory agent and the like.
[0003] As a production method of cis-4-hydroxy-L-proline, a method of organic synthesis of a cis-4-hydroxy-L-proline derivative from a trans-4-hydroxy-L-proline derivative has been proposed (patent document 1). However, it has a problem in that a trans-4-hydroxy-L-proline derivative, which is the synthesis starting material, itself is expensive. While methods of producing cis-4-hydroxy-L-proline from L-proline by using microorganisms such as the genus Helicoceras and the like have also been proposed (patent documents 2 and 3), the production amount is extremely as low as 0.65 g/L, and is not practical.
[0000] patent document 1: JP-A-2005-112761
patent document 2: JP-B-3005085
patent document 3: JP-B-3005086
DISCLOSURE OF THE INVENTION
Problems to be Solved by the Invention
[0004] There is a need to develop a method of economically and efficiently producing industrially useful cis-4-hydroxy-L-proline.
Means of Solving the Problems
[0005] The present invention provides L-proline cis-4-hydroxylase. The L-proline cis-4-hydroxylase of the present invention may be selected from the group consisting of ((1) a protein consisting of the amino acid sequence of SEQ ID NO: 1 or 2, (2) a protein consisting of an amino acid sequence wherein one or several amino acids is/are deleted from, substituted in or added to the amino acid sequence of SEQ ID NO: 1 or 2, which has L-proline cis-4-hydroxylase activity, (3) a protein consisting of an amino acid sequence having homology of not less than 80% with the amino acid sequence of SEQ ID NO: 1 or 2, which has L-proline cis-4-hydroxylase activity, (4) a protein consisting of an amino acid sequence encoded by a polynucleotide consisting of a nucleotide sequence having homology of not less than 80% with the nucleotide sequence of SEQ ID NO: 3 or 4, which has L-proline cis-4-hydroxylase activity, (5) a protein consisting of an amino acid sequence encoded by a polynucleotide that hybridizes with a polynucleotide consisting of the nucleotide sequence of SEQ ID NO: 3 or 4 under stringent conditions, which has L-proline cis-4-hydroxylase activity, and (6) a fusion protein of any of the proteins of the aforementioned (1) to (5) and a tag peptide for specific binding attached thereto.
[0006] The present invention provides a production method of cis-4-hydroxy-L-proline. The production method of the cis-4-hydroxy-L-proline of the present invention includes a step of providing the L-proline cis-4-hydroxylase of the present invention and L-proline, and
[0000] (2) a step of reacting the aforementioned L-proline cis-4-hydroxylase with the aforementioned L-proline to give cis-4-hydroxyproline.
[0007] The present invention provides a recombinant vector containing polynucleotide encoding the L-proline cis-4-hydroxylase of the present invention.
[0008] The present invention provides a transformant containing the recombinant vector of the present invention.
[0009] In the present specification, the “protein”, “peptide”, “oligopeptide” and “polypeptide” are compounds wherein two or more amino acids are connected by peptide bond(s). The “protein”, “peptide”, “oligopeptide” and “polypeptide” may be modified by an alkyl group including methyl group, a phosphate group, a sugar chain, and/or an ester bond or other covalent bond. In addition, the “protein”, “peptide”, “oligopeptide” and “polypeptide” may be bound or associated with a metal ion, coenzyme, allosteric ligand, other atom, ion or atomic group, or other “protein”, “peptide”, “oligopeptide” or “polypeptide”, or biopolymer such as sugar, lipid, nucleic acid and the like, or polystyrene, polyethylene, polyvinyl, polyester or other synthetic polymer, via a covalent bond or noncovalent bond.
[0010] When amino acid is indicated in the present specification, it may be shown by a compound name such as L-asparagine, L-glutamine and the like, or by conventionally-used 3 letters such as Asn, Gln and the like. When a compound name is used, a prefix (L- or D-) showing the steric configuration relating to a carbon of the amino acid is used therefor. When the conventional 3 letters are used, the 3 letters represent an L form of amino acid unless otherwise specified. In the present specification, amino acid is a compound bound with an amino group and a carboxyl group via at least one carbon atom, and is any compound capable of polymerizing by peptide bond. While the amino acid in the present specification includes 20 kinds of L-amino acids used for the translation of protein synthesized from messenger RNA in ribosome in vivo and D-amino acids which are stereoisomers thereof, it is not limited thereto and may include any natural or unnatural amino acid.
[0011] In the present specification, isomers of hydroxyproline (hereinafter to be referred to as “Hyp”) may be indicated as trans-3-Hyp, cis-3-Hyp, trans-4-Hyp and cis-4-Hyp depending on the difference in the site where a hydroxyl group is introduced (carbon atom at the 3-position or the 4-position), and the difference in the spatial configuration of a hydroxyl group (trans configuration or cis configuration).
[0012] The structure of cis-4-hydroxy-L-proline (cis-4-Hyp) is represented by chemical formula I.
[0000]
[0013] The L-proline cis-4-hydroxylase of the present invention is produced by expressing a DNA consisting of a nucleotide sequence encoding the amino acid sequence thereof in a nonliving expression system or an expression system using a host organism and an expression vector. The aforementioned host organism includes procaryotes such as Escherichia coli, Bacillus subtilis and the like, and eucaryotes such as yeast, fungi, plant, animal and the like. The expression system using a host organism and an expression vector of the present invention may be a part of an organism such as cell and tissue, or a whole individual organism. The enzyme protein of the present invention may be used, as long as it has L-proline cis-4-hydroxylase activity, for the production method of cis-4-Hyp of the present invention in admixture with other components derived from a nonliving expression system or expression system using a host organism and an expression vector. When the enzyme protein of the present invention is expressed in the aforementioned expression system using a host organism and an expression vector, the host organism that expresses the aforementioned enzyme protein, for example, the transformant of the present invention, which is used for the production of cis-4-Hyp of the present invention, may be in a living state. In this case, the cis-4-Hyp of the present invention can be produced by a resting microbial cell reaction system or a fermentation method. Alternatively, the aforementioned enzyme protein may be purified for use in the production method of the cis-4-Hyp of the present invention.
[0014] The amino acid sequence of SEQ ID NO: 1 and the nucleotide sequence of SEQ ID NO: 3 are the amino acid sequence of BAB52605 protein derived from Lotus corniculatus rhizobia, Mesorhizobium loti MAFF303099, and the nucleotide sequence of a gene encoding the BAB52605 protein, respectively. The BAB52605 protein has an ability to convert L-proline to cis-4-Hyp. The amino acid sequence of SEQ ID NO: 1 is deposited under Accession No. BAB52605 in the database GenBank. The nucleotide sequence of SEQ ID NO: 3 is deposited under Accession No. BA000012 in the database GenBank. While the BAB52605 protein was annotated as L-proline 3-hydroxylase in GenBank, the protein actually has L-proline cis-4-hydroxylase activity that produces cis-4-Hyp from proline, and does not show L-proline 3-hydroxylase activity, as shown in the Examples of the present invention.
[0015] The amino acid sequence of SEQ ID NO: 2 and the nucleotide sequence of SEQ ID NO: 4 are the amino acid sequence of CAC47686 protein derived from Medicago saliva rhizobia, Sinorhizobium meliloti 1021, and the nucleotide sequence of the gene encoding the CAC47686 protein. The CAC47686 protein has an ability to convert L-proline to cis-4-Hyp. The amino acid sequence of SEQ ID NO: 2 is deposited under Accession No. CAC47686 in the database GenBank/EMBL. The amino acid sequence of SEQ ID NO 4 is deposited under Accession No. AL591792 in the database GenBank.
[0016] In the present specification, the homology of the nucleotide sequence is represented by the percentage obtained by aligning the nucleotide sequence of the present invention and that of a comparison object such that the nucleotide sequences match with each other most, and dividing the number of nucleotides in the matched parts of the nucleotide sequence by the total number of the nucleotides of the nucleotide sequence of the present invention. Similarly, the homology of the amino acid sequence in the present specification is represented by the percentage obtained by aligning the amino acid sequence of the present invention and that of a comparison object such that the highest number of amino acid residues match between the amino acid sequences, and dividing the number of the matched amino acid residues by the total number of the amino acid residues of the amino acid sequence of the present invention. The homology of the nucleotide sequence and amino acid sequence of the present invention can be calculated by using an alignment program CLUSTALW well known to those of ordinary skill in the art.
[0017] In the present specification, the “stringent conditions” mean to perform Southern blotting method explained in Sambrook, J. and Russell, D. W., Molecular Cloning A Laboratory Manual 3rd Edition, Cold Spring Harbor Laboratory Press (2001) under the following experiment conditions. A polynucleotide consisting of the nucleotide sequence of the comparison object is subjected to agarose electrophoresis to allow formation of a band, and immobilized on a nitrocellulose filter or other solid phase by capillary phenomenon or electrophoresis, and prewashed with a solution of 6×SSC and 0.2% SDS. A polynucleotide comprising the nucleotide sequence of the present invention is labeled with a labeling substance such as radioisotope and the like to give a probe and a hybridization reaction of the probe with the aforementioned comparison object polynucleotide immobilized on the solid phase is performed overnight in a solution of 6×SSC and 0.2% SDS at 65° C. Thereafter, the aforementioned solid phase is washed twice each with a solution of 1×SSC and 0.1% SDS at 65° C. for 30 min and washed twice each with a solution of 0.2×SSC and 0.1% SDS at 65° C. for 30 min. Finally, the amount of the probe remaining on the aforementioned solid phase is determined by quantifying the aforementioned labeling substance. In the present specification, hybridization under the “stringent conditions” means that the amount of a probe remaining on a solid phase on which a polynucleotide consisting of the nucleotide sequence of a comparison object is immobilized is at least 25%, preferably at least 50%, more preferably at least 75%, of the amount of a probe remaining on a solid phase for a positive control experiment, on which a polynucleotide consisting of the nucleotide sequence of the present invention is immobilized.
[0018] The protein of the present invention may be selected from the group consisting of (1) a protein consisting of the amino acid sequence of SEQ ID NO: 1 or 2, (2) a protein consisting of an amino acid sequence wherein one or several amino acids is/are deleted from, substituted in or added to the amino acid sequence of SEQ ID NO: 1 or 2 SEQ ID NO: 1 or 2, which has L-proline cis-4-hydroxylase activity, (3) a protein consisting of an amino acid sequence having homology of not less than 80% with the amino acid sequence of SEQ ID NO: 1 or 2, which has L-proline cis-4-hydroxylase activity, (4) a protein consisting of an amino acid sequence encoded by a polynucleotide consisting of a nucleotide sequence having homology of not less than 80% with the nucleotide sequence of SEQ ID NO: 3 or 4, which has L-proline cis-4-hydroxylase activity, (5) a protein consisting of an amino acid sequence encoded by a polynucleotide that hybridizes with a polynucleotide consisting of the nucleotide sequence of SEQ ID NO: 3 or 4 under stringent conditions, which has L-proline cis-4-hydroxylase activity, and (6) a fusion protein of any of the proteins of the aforementioned (1) to (5) and a tag peptide for specific binding attached thereto.
[0019] The fusion protein of the present invention consists of a tag peptide for specific binding and any of the proteins of the aforementioned (1) to (5), wherein the peptide is attached to the amino terminal or carboxyl terminal of said protein.
[0020] The tag peptide for specific binding of the present invention is a polypeptide that specifically binds to other proteins, polysaccharides, glycolipids, nucleic acids, derivatives of these, resins and the like, to facilitate detection, separation or purification of expressed protein when any of the proteins of the aforementioned (1) to (5) is prepared. A ligand bound to the tag for specific binding may also be immobilized on a solid support or dissolved in a free form in an aqueous solution. Thus, since the fusion protein of the present invention specifically binds to a ligand immobilized on a solid support, other components in the expression system can be removed by washing. Thereafter, the aforementioned fusion protein can be separated from the solid support and collected by adding a ligand in a free form or changing pH, ion intensity and other conditions. The tag for specific binding of the present invention includes, but is not limited to, His tag, myc tag, HA tag, intein tag, MBP, GST and polypeptides analogous thereto. The tag for specific binding of the present invention may have any amino acid sequence as long as the fusion protein retains N-terminal amidase activity.
[0021] The L-proline cis-4-hydroxylase activity of the protein of the present invention may be evaluated by quantifying cis-4-Hyp produced by reacting the protein of the present invention with L-proline in a reaction solution of the protein of the present invention, L-proline, 2-oxoglutaric acid, divalent ferric ion and L-ascorbic acid.
[0022] The cis-4-Hyp may be quantified by using an analytical instrument well known to those of ordinary skill in the art, such as LC/MS and the like.
[0023] Step (2) of the production method of the present invention may be performed using a reaction solution of a buffer component for pH control in addition to the composition of the present invention and L-proline. HEPES is preferably used as the aforementioned buffer component, and pH may be adjusted to 7.0-7.5. Preferably, the aforementioned reaction solution may further contain 2-oxoglutaric acid involved as an electron donor in a hydroxide reaction by the protein of the present invention. The aforementioned reaction solution may further contain divalent ferric ion, L-ascorbic acid and the like.
[0024] To allow the composition of the present invention to react with L-proline in step (2) of the production method of the present invention, the reaction solution is incubated for a predetermined reaction time at a predetermined reaction temperature. In the production method of the present invention, the concentration of the composition of the present invention, L-proline, divalent ferric ion, 2-oxoglutaric acid and the like in the reaction solution, reaction solution volume, reaction time, reaction temperature or other reaction conditions may be determined by those of ordinary skill in the art in consideration of the relationship between the desired production amounts and yield of cis-4-Hyp, time, cost, facility and the like necessary for the production, and other conditions.
[0025] The cis-4-Hyp obtained by the production method of the present invention may be collected by a combination of operations well known to those of ordinary skill in the art, such as centrifugation, column chromatography, freeze-drying and the like. In addition, the cis-4-Hyp obtained by the production method of the present invention may be evaluated for the production amounts or purity by using analysis techniques well known to those of ordinary skill in the art, such as LC/MS.
[0026] In the present specification, the “recombinant vector” is a vector incorporating a polynucleotide encoding a protein having a desired function, which is used to afford expression of the protein having the desired function in the host organism.
[0027] In the present specification, the “vector” is a genetic factor used to afford replication and expression of a protein having a desired function in a host organism by incorporating a polynucleotide encoding the protein having the desired function therein and transducing same to the host organism. Examples thereof include, but are not limited to, plasmid, virus, phage, cosmid and the like. Preferably, the aforementioned vector may be a plasmid. More preferably, the aforementioned vector may be a pET-21d(+) plasmid.
[0028] The recombinant vector of the present invention may be produced by ligating a polynucleotide encoding the protein of the present invention and any vector according to a genetic engineering method well known to those of ordinary skill in the art who use restriction enzymes, DNA ligases and the like.
[0029] In the present specification, the “transformant” is an organism into which a recombinant vector incorporating a polynucleotide encoding a protein having a desired function has been transduced, and which has become capable of showing desired property relating to the protein having the desired function.
[0030] In the present specification, the “host organism” is an organism into which a recombinant vector incorporating a polynucleotide encoding a protein having a desired function is transduced for production of a transformant. The aforementioned host organism includes procaryotes such as Escherichia coli, Bacillus subtilis and the like, and eucaryotes such as yeast, fungi, plant, animal and the like. The aforementioned host organism may be Escherichia coli.
[0031] The transformant of the present invention is produced by transducing the recombinant vector of the present invention into any appropriate host organism. The recombinant vector may be transduced according to various methods well known to those of ordinary skill in the art, such as electroporation method forming a pore in the cellular membrane by electric stimulation, a heat shock method to be performed along with a calcium ion treatment and the like.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] FIG. 1 Maps of recombinant plasmids.
[0033] FIG. 2 A conceptual diagram showing the procedures of quenching reaction in a hydroxide reaction test and derivatization of amino acid.
[0034] FIG. 3 Graphs showing the results of HPLC analyses of standard samples of L-proline and 4 kinds of isomers of Hyp.
[0035] FIG. 4 Graphs showing the results of HPLC analyses of a standard reaction solution from reaction with a cell-free extract containing BAB52605 protein, a Pro-free reaction solution (negative control) and a 2-OG-free reaction solution (negative control).
[0036] FIG. 5 Graphs showing the results of HPLC analyses of a standard reaction solution from reaction with a cell-free extract containing CAC47686 protein, a Pro-free reaction solution (negative control) and a 2-OG-free reaction solution (negative control).
[0037] FIG. 6 A graph showing the results of HPLC analysis of a nonexpressing reaction solution (negative control).
[0038] FIG. 7 A conceptual diagram showing procedures for preparation of an MS analysis sample.
[0039] FIG. 8 Graphs showing the results of MS analyses of standard reaction solutions from reaction with cell-free extracts containing BAB52605 protein and CAC47686 protein.
[0040] FIG. 9 Graphs showing fragmentation patterns obtained by MS/MS/MS analyses of reaction products in standard reaction solutions from reaction with cell-free extracts containing BAB52605 protein and CAC47686 protein, and a standard sample of cis-4-Hyp.
DESCRIPTION OF EMBODIMENTS
[0041] The present invention is explained in detail in the following by referring to Examples, which are not to be construed as limitative.
Example 1
1. Cloning, Transduction and Expression of Genes Encoding Proteins BAB52605 and CAC47686
1-1. Method
(Extraction of Microorganism Chromosomal DNA to be Used as Template for Gene Amplification)
[0042] Lotus corniculatus rhizobia, Mesorhizobium loti MAFF303099, was obtained from National Institute of Agrobiological Sciences Genebank, and Medicago sativa rhizobia, Sinorhizobium meliloti 1021 (NBRC 14782 T ), was obtained from National Institute of Technology and Evaluation, and chromosomal DNAs thereof were used as templates for gene amplification.
[0043] The aforementioned two kinds of microorganisms were subjected to liquid shaking culture in 5 mL of TY medium (0.5% Bacto Trypton, 0.3% Bacto Yeast extract, 0.04% CaCl 2 ) at 28° C. for 3 days. After the culture, bacterial cells were collected by centrifugation (4° C., 5000×g, 10 min), and chromosomal DNAs were extracted from the bacterial cells according to a conventional method.
(Amplification of Object Gene)
[0044] A gene encoding the enzyme of the present invention shown in Table 1 was amplified by a polymerase chain reaction (PCR) using chromosomal DNA of each bacterial cell as a template. Expand High Fidelity PCR System (Roche) was used for the aforementioned PCR. The reaction conditions are shown in Table 2. The conditions for the cloning and expression are shown in Table 3. The sense primers and antisense primers using Lotus corniculatus rhizobia, Mesorhizobium loti MAFF303099, and Medicago sativa rhizobia, Sinorhizobium meliloti 1021, as templates are shown in SEQ ID NOs: 5 and 6, and SEQ ID NOs: 7 and 8, respectively.
[0000]
TABLE 1
Proline hydroxylase used for experiment
Putative protein
Amino
Microorganism to
GenBank
function
Number
acid
be gene source
Strain name
Protein No.
published
of bases
residue
Mesorhizobium
MAFF303099
BAR52605.1
L-proline 3-
843
280
loti
hydroxylase
Sinorhizobium
NBRC 14782 T
CAC47686.1
PUTATIVE L-
843
280
meliloti
PROLINE 3-
HYDROXYLASE
PROTEIN
[0000]
TABLE 2
PCR conditions
Temperature (° C.)
Time (sec)
Cycle
94
180
1
94
15
25
50
10
72
50
72
420
1
[0000]
TABLE 3
Cloning and expression conditions
BAB52605.1
CAC47686.1
No
Item
( Mesorhizobium loti )
( Sinorhizobium meliloti )
1
Host
Escherichia coli Rosetta2 (DE3)
Vector
pET-21d (+)
2
Primer
Sense
5′-TGAATATACCATGGCAACG
5′-TGAATATACCATGGGCACCC
CGGATATTGGGTGTGGTC-3′
ATTTCTTGGGCAAGG-3′
Anti-sense
5′-ATGAATTCAAGCTTATAAG
5′-ATGAATTCAAGCTTGTATGT
TCATGACCTCGCCAGCAGCAC-3′
CATCACCTCGCCACGTTC-3′
3
Restriction
5′ side
Nco I
enzyme
3′ side
Hind III
recognition
sequence
4
Culture
Pre-culture
inoculation of single colony to LB medium
method
(5 ml) + Amp 100 μg/ml + Cm 34 μg/ml
(expression)
↓
culture at 37° C., 200 rpm, 16 hr
Main culture
addition of pre-culture medium (1 ml) to LB medium (100
ml)+ Amp 100 μg/ml + Cm 34 μg/ml, and culture at 37° C.,
200 rpm to reach O.D. 650 = 0.5
↓
addition of IPTG (final concentration 0.1 mM) and culture
at 25° C., 100 rpm, 9 hr
(Obtainment of Recombinant Plasmid)
[0045] The object DNA amplified by PCR was used as insert DNA, and each insert DNA (1 μg) and a vector, pET-21d(+) (1 μg), were cleaved by a reaction using restriction enzymes NcoI and HindIII at 37° C. for 16 hr. The cleavage products were purified by GFX PCR Purification Kit (GE Healthcare), and each insert DNA and vector were ligated by a reaction using DNA Ligation Kit <Mighty Mix> (Takara) at 16° C. for 3 hr. The ligation product was transduced by a heat shock method into Escherichia coli JM109 treated with calcium chloride. Escherichia coli JM109 carrying each recombinant plasmid was cultured in an LB-A agar medium (1% Bacto Trypton, 0.5% Bacto Yeast extract, 1% NaCl, 1.5% Bacto Agar, 100 μg/mL ampicillin) at 37° C. for 16 hr, and then cultured in an LB-A liquid medium (1% Bacto Trypton, 0.5% Bacto Yeast extract, 1% NaCl, 100 μg/mL ampicillin, 5 mL) at 37° C. for 1.6 hr, after which the plasmid was extracted using QIAprep Spin Miniprep Kit (QIAGEN). The internal base sequence of the extracted plasmid was analyzed by a DNA Sequencer to confirm insertion of desired DNA. The plasmid maps of the produced recombinant plasmids are shown in FIG. 1 .
(Expression of Object Gene)
[0046] The recombinant plasmids confirmed of insertion of DNA encoding each of BAB52605 protein and CAC47686 protein (to be referred to as pEBAB52605 and pECAC47686, respectively) were transduced by a heat shock method into Escherichia coli Rosetta 2 (DE3) treated with calcium chloride, and expressed by the procedures shown in Table 3. That is, the aforementioned Escherichia coli was cultured in an LB-AC agar medium (1% Bacto Trypton, 0.5% Bacto Yeast extract, 1% NaCl, 1.5% Bacto Agar, 100 μg/mL ampicillin, 34 μg/mL chloramphenicol) at 37° C. overnight. The single colony grown was inoculated in an LB-AC liquid medium (1% Bacto Trypton, 0.5% Bacto Yeast extract, 1% NaCl, 100 μg/mL ampicillin, 34 μg/mL chloramphenicol, 5 mL), and cultured with shaking at 37° C. and 200 rpm for 16 hr. Thereafter, the aforementioned liquid medium (1 mL) was added to a fresh LB-AC liquid medium (100 mL), and cultured with shaking at 37° C. and 200 rpm. At the time point when O.D. 660 =0.5 was reached, isopropyl-β-d-thiogalactopyranoside (IPTG) was added to a final concentration of 0.1 mM, the mixture was cultured at 25° C. and 100 rpm to induce gene expression. After 9 hr, the cultured cells were collected by centrifugation (4° C., 5000×g, 10 min), and suspended in 20 mM HEPES NaOH buffer (pH 7.5, 5 mL) The aforementioned suspension was disrupted by ultrasonication (3 min), centrifuged (4° C., 20000×g, 30 min), and the supernatant (cell-free extract) was collected.
1-2. Results
[0047] By the aforementioned extraction and amplification operation, genes encoding BAB52605 protein and CAC47686 protein were successfully cloned. By the aforementioned recombinant operation and the like, recombinant plasmids containing the aforementioned genes could be produced. The plasmid maps of the obtained recombinant plasmids are shown in FIG. 1 . By the transduction operation of the aforementioned recombinant plasmids, transformants having the recombinant plasmids could be produced. By the expression operation of the aforementioned genes by the aforementioned transformants, cell-free extracts containing BAB52605 protein and CAC47686 protein could be respectively obtained. The obtained cell-free extracts were used for the following experiments.
Example 2
2. Hydroxylation Reaction of L-Proline with BAB52605 Protein and CAC47686 Protein
2-1. Method
[0048] Hydroxylation reaction of L-proline with a cell-free extract containing BAB52605 protein or CAC47686 protein obtained in Example 1 was performed. A reaction solution of the composition shown in Table 4 (hereinafter to be referred to as “standard reaction solution”) was prepared, and the reaction was performed with stirring at 30° C. and 170 rpm for 30 min. In addition, as a negative control, a reaction solution obtained by excluding L-proline from the standard reaction solution (hereinafter to be referred to as “Pro-free reaction solution”), a reaction solution free of 2-oxoglutaric acid (2-OG) (hereinafter to be referred to as “2-OG-free reaction solution”), and a reaction solution containing, instead of the cell-free extracts containing BAB52605 protein and CAC47686 protein, a cell-free extract of Escherichia coli Rosetta 2 (DE3) free of a vector expressing the aforementioned proteins (hereinafter to be referred to as “nonexpressing reaction solution”) were prepared, and the reaction was performed with stirring at 30° C. and 170 rpm for 30 min in the same manner as with the standard reaction solution. After the reaction, according to the procedures shown in FIG. 2 , the reaction was quenched and whole amino acids contained in the reaction solution was derivatized using a Marfey's reagent (1-fluoro-2,4-dinitrophenyl-5-L-leucinamide). Thereafter, the reaction solution was filtered with a 0.45 μm filter, and subjected to high performance liquid chromatography (HPLC) analysis. Various conditions of HPLC analysis are shown in Tables 5A and 5B. In addition, for molecular weight measurement of the resultant products, mass spectrometry (MS analysis) of the standard reaction solutions after reaction with a cell-free extract containing BAB52605 protein or CAC47686 protein was performed. According to the procedures shown in FIG. 7 , the substance in the reaction solution was purified using an ion exchange column (Waters Oasis HLB 6 cc Extraction Cartridge), dried to solidness under reduced pressure and dissolved in methanol to give an MS analysis sample. The conditions of MS analysis are shown in Table 6.
[0000]
TABLE 4
Reaction composition
L-Proline
5.0
mM
2-Oxoglutarate
10
mM
L-Ascorbate
1.0
mM
FeSO 4
0.5
mM
HEPES
100
mM
Cell-free extract
1.0
mg
Total volume 1 ml 30° C., 30 min, shake
[0000]
TABLE 5
HPLC analysis conditions
(a) Setting
Apparatus
Hitachi high performance liquid chromatograph
used
L-2000 series
Analytical
XDB-C18 (5 μm), 4.6 mm × 150 mm (Agilent)
column
Column
40° C.
temperature
Detector
UV 340 nm
Eluent
A
50 mM KH 2 PO4/CH 3 OH/CH 3 CN = 90/5/5
B
50 mM KH 2 PO4/CH 3 OH/CH 3 CN = 60/5/35
C
CH 3 CN/THF/H 2 O = 60/20/20
(b) Pump program
Time (min)
A (%)
B (%)
C (%)
Flow rate (ml/min)
0.0
100
0
0
1.0
54.0
55
45
0
54.1
0
0
100
60.0
0
0
100
60.1
100
0
0
75.0
100
0
0
[0000]
TABLE 6
MS analysis conditions
Apparatus used
LCQ Deca (Thermo Quest)
ESI positive
Setting
Sheath Gas Flow Rate
20 arb
Aux Gas Flow Rate
20 arb
Spray Voltage
5 kV
Capillary Temp
200° C.
Capillary Vortage
17 V
Tube Lens offset
5 V
2-2. Results.
[0049] FIG. 3 shows the results of HPLC analysis of standard samples of L-proline and 4 kinds of isomers of Hyp. Since any isomer of Hyp was detected as a separated single peak, the peak substance was identified based on the retention time.
[0050] FIG. 4 shows the results of the HPLC analysis of standard reaction solutions obtained by a reaction with a cell-free extract containing BAB52605 protein, a Pro-free reaction solution (negative control) and a 2-OG-free reaction solution (negative control). While the standard reaction solutions showed a decrease in the peak of L-proline and emergence of peak of cis-4-Hyp, the 2-OG-free reaction solution showed a peak of L-proline alone, and the Pro-free reaction solution showed no peak.
[0051] FIG. 5 shows the results of the HPLC analysis of standard reaction solutions obtained by a reaction with a cell-free extract containing CAC47686 protein, a Pro-free reaction solution (negative control) and a 2-OG-free reaction solution (negative control). Like the results of FIG. 4 using BAB52605 protein, while the standard reaction solutions showed a decrease in the peak of Pro and emergence of peak of cis-4-Hyp, the 2-OG-free reaction solution showed a peak of Pro alone, and the Pro-free reaction solution showed no peak. (Since the small peak in 33 min observed with the 2-OG-free reaction solution was also observed with the Pro-free reaction solution, the peak is considered to be derived from a substance originally contained in the reaction solution, which is not a substrate or a resultant product.)
[0052] FIG. 6 shows the results of the HPLC analysis of nonexpressing reaction solution (negative control). The nonexpressing reaction solution showed only a peak of L-proline.
[0053] FIG. 8 shows the results of the MS analysis of standard reaction solutions obtained by a reaction with a cell-free extract containing BAB52605 protein (upper panel) or CAC47686 protein (lower panel). In respective analysis results, protonated ion (m/z=426.1) and sodium added ion (m/z=448.1) corresponding to cis-4-Hyp derivatives were detected.
[0054] FIG. 9 shows fragmentation patterns obtained by MS/MS/MS analyses of reaction products in standard reaction solutions from reaction with cell-free extracts containing BAB52605 protein (upper panel) and CAC47686 protein (middle panel), and a standard sample of cis-4-Hyp (lower panel). In respective analysis results, a common fragmentation pattern was observed, which confirms that the fragmentation patterns of MS/MS/MS analyses of the reaction products from cell-free extracts containing the aforementioned proteins are the same as the pattern of the cis-4-Hyp standard sample.
[0055] From these results, since cis-4-Hyp is produced in the presence of BAB52605 or CAC47686 protein and L-proline, it has been confirmed that the aforementioned proteins are all hydroxygenases that regioselectively and sterically selectively hydroxylate L-proline and produce cis-4-Hyp. The putative protein function disclosed in the databases such as Entrez Protein and the like is “L-proline 3-hydroxylase” for BAB52605 protein and “PUTATIVE L-PROLINE 3-HYDROXYLASE PROTEIN” for CAC47686 protein. However, the results of this experiment confirm that the function of the both proteins mentioned above is L-proline cis-4-hydroxylase and L-proline 3-hydroxylase activity is absent. Moreover, since cis-4-Hyp is produced in the presence of 2-OG in reactions catalyzed by BAB52605 or CAC47686 protein, both the aforementioned proteins were confirmed to be 2-OG dependent dioxygenases that add an oxygen atom between the carbon atom at the 4-position of Pro and a hydrogen atom bonded thereto in the presence of 2-OG. | Development of a method of economically and efficiently producing cis-4-hydroxy-L-proline. The present invention provides L-proline cis-4-hydroxylase. This enzyme may be derived from Lotus corniculatus rhizobia, Mesorhizobium loti or Medicago sativa rhizobia, Sinorhizobium meliloti . The present invention provides a method of producing cis-4-hydroxy-L-proline from L-proline by using this enzyme. The present invention provides a recombinant vector containing a polynucleotide encoding the enzyme and a transformant containing the vector. | 2 |
CROSS REFERENCE TO RELATED APPLICATIONS
This document claims priority to and incorporates by reference all of the subject matter included in the provisional patent application having Ser. No. 61/536,959, and filed Sep. 20, 2011.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to friction stir welding (FSW) and its variations including but not limited to friction stir processing (FSP), friction stir spot welding (FSSW), friction stir spot joining (FSSJ), friction bit joining (FBJ), friction stir fabrication (FSF) and friction stir mixing (FSM) (and hereinafter referred to collectively as “friction stir welding”).
2. Description of Related Art
Friction stir welding is a technology that has been developed for welding metals and metal alloys. Friction stir welding is generally a solid state process. Solid state processing is defined herein as a temporary transformation into a plasticized state that typically does not include a liquid phase. However, it is noted that some embodiments allow one or more elements to pass through a liquid phase, and still obtain the benefits of the present invention.
The friction stir welding process often involves engaging the material of two adjoining work pieces on either side of a joint by a rotating stir pin. Force is exerted to urge the pin and the work pieces together and frictional heating caused by the interaction between the pin, shoulder and the work pieces results in plasticization of the material on either side of the joint. The pin and shoulder combination or “FSW tip” is traversed along the joint, plasticizing material as it advances, and the plasticized material left in the wake of the advancing FSW tip cools to form a weld. The FSW tip can also be a tool without a pin so that the shoulder is processing another material through FSP.
FIG. 1 is a perspective view of a tool being used for friction stir welding that is characterized by a generally cylindrical tool 10 having a shank 8 , a shoulder 12 and a pin 14 extending outward from the shoulder. The pin 14 is rotated against a work piece 16 until sufficient heat is generated, at which point the pin of the tool is plunged into the plasticized work piece material. Typically, the pin 14 is plunged into the work piece 16 until reaching the shoulder 12 which prevents further penetration into the work piece. The work piece 16 is often two sheets or plates of material that are butted together at a joint line 18 . In this example, the pin 14 is plunged into the work piece 16 at the joint line 18 .
Referring to FIG. 1 , the frictional heat caused by rotational motion of the pin 14 against the work piece material 16 causes the work piece material to soften without reaching a meting point. The tool 10 is moved transversely along the joint line 18 , thereby creating a weld as the plasticized material flows around the pin from a leading edge to a trailing edge along a tool path 20 . The result is a solid phase bond at the joint line 18 along the tool path 20 that may be generally indistinguishable from the work piece material 16 , in contrast to the welds produced when using conventional noon-FSW welding technologies.
It is observed that when the shoulder 12 contacts the surface of the work pieces, its rotation creates additional frictional heat that plasticizes a larger cylindrical column of material around the inserted pin 14 . The shoulder 12 provides a forging force that contains the upward metal flow caused by the tool pin 14 .
During friction stir welding, the area to be welded and the tool are moved relative to each other such that the tool traverses a desired length of the weld joint at a tool/work piece interface. The rotating friction stir welding tool 10 provides a continual hot working action, plasticizing metal within a narrow zone as it moves transversely along the base metal, while transporting metal from the leading edge of the pin 14 to its trailing edge. As the weld zone cools, there is typically no solidification as no liquid is created as the tool 10 passes. It is often the case, but not always, that the resulting weld is a defect-free, re-crystallized, fine grain microstructure formed in the area of the weld.
Travel speeds are typically 10 to 500 mm/min with rotation rates of 200 to 2000 rpm. Temperatures reached are usually close to, but below, solidus temperatures. Friction stir welding parameters are a function of a material's thermal properties, high temperature flow stress and penetration depth.
Previous patents have taught the benefits of being able to perform friction stir welding with materials that were previously considered to be functionally unweldable. Some of these materials are non-fusion weldable, or just difficult to weld at all. These materials include, for example, metal matrix composites, ferrous alloys such as steel and stainless to and non-ferrous materials. Another class of materials that were also able to take advantage of friction stir welding is the superalloys. Superalloys can be materials having a higher melting temperature bronze or aluminum, and may have other elements mixed in as well. Some examples of superalloys are nickel, iron-nickel, and cobalt-based alloys generally used at temperatures above 1000 degrees F. Additional elements commonly found in superalloys include, but are not limited to, chromium, molybdenum, tungsten, aluminum, titanium, niobium, tantalum, and rhenium.
It is noted that titanium is also a desirable material to use for friction stir welding. Titanium is a non-ferrous material, but has a higher melting point than other nonferrous materials. The previous patents teach that a tool for friction stir welding of high temperature materials is made of a material or materials that have a higher melting temperature than the material being friction stir welded. In some embodiments, a superabrasive was used in the tool, sometimes as a coating.
Friction Stir Welding (FSW) has been in use now for almost 20 years as a solid state joining process. This process has evolved from being used on aluminum or low melting temperature materials to high melting temperature materials such as steel, stainless steel, nickel base alloys and others. Literature is replete with tool geometries and process parameters needed to have a repeatable process. An understanding of the FSW process is important to understanding the invention described below.
While FIG. 1 describes the general joining process, there is one particular problem that was not described. Once a friction stir weld or friction stir processing pass is complete, the starting point of the joint may be left with material flash caused by the initial tool plunge. In many applications, having material flash disposed on a work piece after FSW is unacceptable.
One method for removing material flash is a run-on tab. However, using a run-on tab may also lead to a requirement for additional fixturing, work piece material, and post process removal methods. Furthermore, in many cases, a run-on tab is not an option because of space limitations, work piece geometry, cost, etc.
An example of an application where a run-on tab may not be an option would be using FSW to repair certain cracks. For example, nuclear reactor containment vessels may not have the option for a run-on tab. Furthermore, the material flash that may be left over from the FSW plunge may create a new corrosion crack initiation site and cannot be tolerated for safety reasons. There are many other examples of how a resulting FSW surface with material flash (hereinafter “flash”) may be detrimental to product performance, safety, and cost.
In some cases, flash resulting from the plunge is not the only detrimental effect resulting from FSW. Other problems from FSW may include unfavorable or detrimental residual stresses, tool undercut, flash along the weld due to tool wear or parameter selection, sharp flash locations creating safety concerns for human contact, inability to see sub-surface defects, fatigue life compromised by surface anomalies and others.
Having a consistent surface finish is preferred for engineered components in order to meet design and safety requirements. Thus, what is needed is a way to join Advanced High Strength Steels (AHSS) that can be used in the automotive and other industries.
BRIEF SUMMARY OF THE INVENTION
it is an object of the present invention to provide a system and method for modifying a work piece surface of high melting temperature materials such as Advanced High Strength Steels, wherein a friction stir welding tool may include cutting elements located on the outside diameter of a collar assembly, wherein the collar assembly may be retrofitted for existing friction stir welding tools, or may be designed as a custom attachment for a new hybrid friction stir welding tool, wherein the surface of the work piece may be modified by removing detrimental flash and burr created during operation of the friction stir welding tool.
These and other objects, features, advantages and alternative aspects of the present invention will become apparent to those skilled in the art from a consideration of the following detailed description taken in combination with the accompanying drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is an illustration of the prior art showing friction stir welding of planar work pieces.
FIG. 2 is a perspective view of a friction stir welding tool that was designed to accommodate cutting elements on an outside diameter or collar of the tool.
FIG. 3 is a close-up view of the results of trying to remove a burr using the friction stir welding tool of FIG. 2 .
FIG. 4 is a perspective view of a floating outer collar for making a hybrid friction stir welding tool of the present invention.
FIG. 5 is a perspective view of the underside of the hybrid friction stir welding tool showing a load pin adjustment used to set the height of a cutting insert.
FIG. 6 is a cross sectional view of the hybrid friction stir welding tool described in FIGS. 4 and 5 .
FIG. 7 is a perspective view of a hybrid friction stir welding tool for removing burrs and/or altering the surface of a work piece during friction stir welding.
FIG. 8 shows a uniformly machined surface of a stainless steel work piece with a burr removed using a hybrid friction stir welding tool modified to incorporate the present invention.
FIG. 9 is a perspective view of a collar assembly that may be used to retrofit an existing friction stir welding tool that already has a collar.
FIG. 10 is a hybrid friction stir welding tool that is a combination of the collar assembly of FIG. 9 and a friction stir welding tool that has a collar.
FIG. 11 is a cross sectional view of the retrofitted friction stir welding tool of FIG. 10 .
FIG. 12 is a profile view of a hybrid friction stir welding tool including a peening surface modification tool.
FIG. 13 is a profile view of a hybrid friction stir welding tool including a grinding surface modification tool.
DETAILED DESCRIPTION OF THE INVENTION
Reference will now be made to the drawings in which the various elements of the present invention will be given numerical designations and in which the invention will be discussed so as to enable one skilled in the art to make and use the invention. It is to be understood that the following description is only exemplary of the principles of the present invention, and should not be viewed as narrowing the claims which follow.
In a first embodiment shown in a perspective view in FIG. 2 , the present invention shows a friction stir welding (hereinafter “FSW”) tool 30 that may be designed to accommodate at least one cutting element 32 on the outside diameter or collar of the tool 30 . Cutting elements 32 may be located on the outside diameter of the FSW tool 30 as shown.
In this embodiment, three cutting elements 32 are disposed on the outside diameter of the FSW tool 30 . The cutting elements 32 are attached using a screw 34 as shown. Accordingly, the cutting elements 32 may be replaced if worn or broken.
The number of cutting elements 32 is not limited to three, and may be decreased to a single cutting element 32 or increased to as many as desired. The cutting elements 32 may be replaceable. The FSW tool 30 may be operated with or without the cutting elements 32 . Accordingly, the cutting elements may or may not be a permanent fixture of the FSW tool 30 .
The cutting elements 30 may be a single material with a cutting edge, or it may be reinforced using additional materials or layers.
Experimental results using the FSW tool 30 of FIG. 2 demonstrate that the cutting elements 32 are effective in removing the detrimental flash and burr created during the plunging of the FSW tool 30 .
FIG. 3 is a top view of a work piece 40 that has been friction stir welded using the FSW tool 30 of FIG. 2 . The work piece 40 shows the results of FSW in stainless steel using the FSW tool 30 shown in FIG. 2 , with three cutting elements 32 . High machine loads were required for this particular FSW geometry and an undesirable deflection of the FSW tool 30 created a natural tilt of a spindle (not shown) that was rotating the FSW tool. This tilt, resulting from a “C Frame” style FSW machine, caused the cutting elements 32 to cut only one side 44 of the processed FSW zone 42 as shown in FIG. 3 . No cutting of the work piece 40 occurred on the opposite side 46 .
Undesirable deflection of the FSW tool 40 would not be a problem if machine loads were low, machine deflection was negligible, or the tool geometry required lower loads. Accordingly, it was determined that the present invention needed further development to allow for FSW tool 30 deflection which is typical during some FSW processes.
FIG. 4 shows a second embodiment of the present invention using a “floating” collar design to create a hybrid. FSW tool. The hybrid FSW tool or floating collar design is comprised of an FSW tool 50 , an inner collar 70 and a floating outer collar 58 , wherein the FSW tool 50 may include a shank 52 , a shoulder 54 and a pin 56 . The FSW tool 50 may or may not include the pin 56 . The floating outer collar 58 is disposed around the inner collar 70 which is disposed around a top portion of the FSW tool 50 .
The floating outer collar 58 may include two diametrically disposed rocker pins 60 that may give the floating outer collar 58 an additional degree of freedom, enabling the floating outer collar 58 to remain in a planer position with respect to the surface of work piece 40 being friction stir welded or processed, while the FSW tool 50 and the inner collar 70 may be deflected to some degree with respect to the work piece 40 while pivoting on the rocker pins 60 .
In this second embodiment, a load pin 62 may remain in contact with a surface of the work piece 40 during FSW, which may offset the loads applied by a cutting insert 64 . In the second embodiment, the three cutting elements 32 have been replaced by a single indexable cutting insert 64 . The second embodiment may also include more than one indexable cutting insert 64 disposed on the floating outer collar 58 .
It should be understood that the FSW tool 50 may have many different profiles and still include some surface modification tool on the floating outer collar 58 . Accordingly, it is within the scope of the invention that the FSW tool may have a shoulder 54 having any profile that is known cc those skilled in the art, including stepped, spiraled, concave, and convex or any other desirable profile. Regarding pins, there may be no pin on the shoulder, there may be a retractable pin or a standard pin. The pin may also have any pin profile that is desirable for the particular application of the FSW tool.
FIG. 5 is a view of the underside of the floating outer collar 58 that may be disposed around the top portion of the FSW tool 50 , and the inner collar 70 . The height of the load pin 62 is adjusted using a cutting height adjustment screw 68 that is underneath the load pin 62 . The cutting height adjustment screw 68 may be an integral part of the load pin or it may be separate. The height of the load pin 62 is adjusted prior to FSW. The load pin 62 is held in place using a set screw 66 .
An outer surface of the inner collar 70 may be spherical to thereby enable continuous rocking or movement of the outer collar, about the rocker pins 60 . This concept of enabling the FSW tool 50 and the inner collar 70 to be able to move with respect to the floating outer collar 58 in order to enable the floating outer collar to remain parallel to a surface of the work piece 40 enables the shank 52 of the FSW tool to be at a variable angle with respect to the surface of the work piece 40 at all times during FSW. In other words, the floating outer collar 58 remains substantially parallel to the surface of a work piece while the friction stir welding tool 50 and the inner collar 70 are free to move and operate at an angle that is not perpendicular to the surface of the work piece.
FIG. 6 is a cross-sectional view of the second embodiment of the present invention. FIG. 6 shows the FSW tool 50 comprised of the pin 56 , the shoulder 54 , and the shank 52 , and two collars comprised of the inner collar 70 and the floating outer collar 58 including the rocker pins 60 (on opposite sides of the inner collar).
FIG. 7 is a perspective view of an FSW tool 50 , inner collar 70 and floating outer collar 58 . The present invention therefore provides an FSW tool having a center geometry that performs FSW, along with an outer geometry that alters the surface of the work piece material being processed.
FIG. 8 shows a uniformly machined surface of a stainless steel work piece 40 . A burr was removed using the FSW tool 50 , the inner collar 70 and the floating outer collar 58 of the present invention.
FIG. 9 is a perspective view of an inner collar 70 and the floating outer collar 58 in a third embodiment that can be coupled to an existing FSW tool (not shown) having a collar. Also shown are the rocker pins 60 on opposite sides of the collars 58 , 70 , as well as the set screw 66 the load pin 62 and the indexable cutting insert 64 . This collar assembly 72 can be coupled to an existing FSW tool as a retrofit in order to take advantage of the principles of the present invention.
FIG. 10 is a perspective view of the collar assembly 72 of FIG. 9 that is now coupled to an existing FSW tool 74 . The FSW tool 74 has its own standard collar 80 , but is now adapted to be coupled to the collar assembly 72 . An adapter collar 82 is coupled to the standard collar 80 using a method that is known to those skilled in the art. The adapter collar 82 may include a lip lock 84 on which the inner collar 70 can rest.
It should be understood that any appropriate means can also be used for attaching the collar assembly 72 to the FSW tool 74 .
FIG. 11 is a cross-sectional view of the embodiment of FIG. 10 , showing retaining lip lock 84 to maintain cutter location during FSW.
FIGS. 2-11 above illustrate the concept of creating a hybrid FSW tool that not only friction stir welds or processes a given work piece, but also machines the surface of the work piece at the same time in order to create the desired surface finish.
The present invention can be further modified by attaching other surface modification tools to the floating outer collar 58 to alter the surface of the work piece according to the designer's design parameters. In other words, in place of the indexable cutting insert 64 , a different tool may be attached to the floating outer collar 58 .
FIG. 12 is a profile view of another hybrid friction stir welding tool 90 of the present invention. In this simplified diagram, an FSW tool 50 has an inner collar 70 and a floating outer collar 58 . FIG. 12 is being shown to illustrate a surface modification tool other than an indexable cutting insert 64 . However, instead of being placed in the same location as the insert, the surface modification tool is disposed in a surface 92 of the floating outer collar 58 . In this figure, at least one elongated ball 94 is disposed in the surface 92 . The ball 94 may be held rigidly in the surface 92 , or it may be free to rotate. The ball 94 is provided for peening or burnishing of the work piece. A plurality of balls 94 may also be disposed in the surface 92 . The balls 94 may be elongated or round.
FIG. 13 is a profile view of another hybrid friction stir welding tool 100 of the present invention. In this simplified diagram, an FSW tool 50 has an inner collar 70 and a floating outer collar 58 . FIG. 13 is being shown to illustrate a surface modification tool other than an indexable cutting insert 64 . However, instead of being placed in the same location as the insert, the surface modification tool is disposed in the surface 92 of the floating outer collar 58 . In this example, at least one wheel 102 is shown disposed in the surface of the floating outer collar 58 . The wheel 102 may be a grinding wheel. The wheel 102 may be replaceable in order to use a wheel having different profiles or materials on the wheel, such as a grit for a grinding wheel. The wheel 102 may use bearings or a pin to enable rotation of the wheel.
Possible surface modification tools include but should not be considered to be limited to a rolling ball that may or may not be located where the indexable cutting insert 64 is now located, the rolling ball being used to create a shot peened surface to create residual compressive stresses, and thereby increasing fatigue life of the work piece. In another embodiment, a stationary ball or ball-like geometry may also be mounted in order to burnish the work piece surface to improve surface finish, reduce corrosion potential and/or improve fatigue properties. In another alternative embodiment, a mirror may also be mounted to provide a reflective surface so that continuous laser processing of the work piece surface may be achieved to alter or reduce surface residual stresses, or laser process the surface of the friction stir processed zone. For materials that harden during the friction stir process, in another alternative embodiment, a grinding fixture may be used to alter the work piece surface as well.
The FSW tools described above will have at least one cutting element or other surface modifying to but may contain more. The FSW tool may have at least one grinding element or feature, at least one burnishing element or feature, at least one peening element or feature, at least one reflective element or feature for laser transmission. In an alternative embodiment, the FSW tool may have more than one feature on a floating outer collar 58 .
The FSW tool may have a rotational speed between 10 and 40200 PPM, and can apply loads between 50 lbf and 60,000 lbf along an FSW tool axis. The FSW tool may use an alternate heating source around the FSW tool using inductive, resistive, IR, or other methods known to the FSW industry. The heating source will affect the characteristics of the resulting weld formed by FSW.
In another alternative embodiment, the FSW tool may use an alternate cooling source around the FSW tool to thereby affect the operating characteristics of the FSW tool. In another alternative embodiment, the FSW tool may have a detachable/modular surface modification tool, or an integrated surface modification tool. The FSW tool may contain any of the metals outlined in the periodic table. The FSW tool may be operated when surrounded by a liquid or fluid, and be used with a shielding gas or operated in air.
The FSW tool may be used to process those materials found in columns 1A through 7A on the Periodic Table and all transition elements and combinations of these elements.
The FSW tool may be modular, or in other words, it may have replaceable components and features that can be attached for modifying a work piece surface. The FSW tool may be used in conjunction with a surface modification tool used on a separate spindle or device. The FSW tool may have a retractable pin, or be used with a bobbin tool design. The FSW tool may also have a shoulder and pin that are controlled independently of the surface modification tool. The FSW tool may operate wherein the surface modification tool operates at different speeds from the friction stirring tool element. The FSW tool may also be operated in a temperature control mode.
The surface modification to that may be coupled to the FSW tool may be any consumable.
The FSW tool may be operated as a spot welding tool with no translation motion.
The FSW tool may have a friction element that is consumable (i.e. friction hydropillar).
The FSW to may be operated wherein no friction element serves as a clamping device. The FSW tool may be used on a non-planer surface.
The work pieces may have another material or greater material thickness than the parent material to allow for stock removal or modification if needed.
Without departing from the scope of this invention, in another alternative embodiment, one or more other spindles may be attached to a machine that is holding and rotating a first FSW tool. It may be possible to allow the FSW process to occur during a same pass, while allowing for different surface speeds to be achieved by using the different spindle heads. Thus, the second spindle head may be movable relative to the position of the first spindle head in order to perform. FSW at some location near to the first spindle head. But not always in the same location relative to the first spindle head.
It is to be understood that the above-described arrangements are only illustrative of the application of the principles of the present invention. Numerous modifications and alternative arrangements may be devised by those skilled in the art without departing from the spirit and scope of the present invention. The appended claims are intended to cover such modifications and arrangements. | A system and method for modifying a work piece surface of high melting temperature materials such as Advanced High Strength Steels, wherein a friction stir welding tool may include cutting elements located on the outside diameter of a collar assembly, wherein the collar assembly may be retrofitted for existing friction stir welding tools, or may be designed as a custom attachment for a new hybrid friction stir welding tool, wherein the surface of the work piece may be modified by removing detrimental flash and burr created during operation of the friction stir welding tool. | 1 |
FIELD OF THE INVENTION
The present invention relates to improvements in diagnostic and surgical procedures, and especially to flexible holders for the stabilization of cystoscopes or other endoscopic instruments or surgical retractors used during diagnostic or surgical procedures. More particularly the invention relates an improved holder clamp which may be situated near the operating or examination table for supporting an endoscope, a retractor or the like after same has begun to have been used in conjunction with a patient.
BACKGROUND OF THE INVENTION
Stabilization of endoscopic equipment during a procedure may be desirable under a variety of circumstances. Colonoscopy is made easier by a stand that supports the weight of the scope, which allows for increased freedom of the hands for manipulation. Surgical manipulation during laparoscopy also is aided by stabilizing the instruments. Other instrument holders have been devised to keep endoscopic instruments untangled and secure on or near the operating table.
In urological practice ureteral catheter or stent placement and routine stone manipulation are facilitated by endoscopic stabilization. A stable cystoscope decreases, radiation exposure to the physician who performs retrograde pyelography by increasing the distance from the radiation source during injection of the contrast agent. Photography is aided by anchoring the cystoscope, as well as visualization of pathological conditions by a succession of students, residents or colleagues. Photodynamic therapy, in which constant light distribution to the bladder mucosa during several minutes is necessary, requires stabilization of the cystoscope.
Several means have been used to stabilize endoscopic equipment, including a variety of stationary adjustable stands and flexible coiled instruments. When no cystoscope holder is available a sling constructed from a surgical towel has been used. Most of these devices are less than ideal because they frequently are awkward or only transiently stable.
Thus, the stabilization of an endoscope during an examination procedure or a retractor during surgery is frequently necessary and presents problems for the physician or surgeon. Most attempts to support endoscopes require holders and supporting arrangements which restrict the physician's mobility to manipulate the instrument to desired locations once the instrument has been positioned. The same problems exist with other instruments, including retractors, during surgery. Over the years, many attempts have been proposed in the patent literature to overcome this cumbersome problem of stability. For example, the U.S. Pat. Nos. 4,457,300 to Budde and 4,573,452 to Greenberg disclose surgical holders for supporting retractors and laparoscopes, respectively. Both of these holders utilize flexible supporting posts or arms for facilitating some movement of the medical equipment during the respective procedures. However, while these flexible posts or arms permit movement of the particular instruments, neither of these holders employ clamps with a sufficient degree of movement and/or rotation and which can accept instruments therein without considerable difficulty. Thus, while these devices are useful, they nevertheless restrict the ease with which a surgeon or physician can mount the instrument to the support once use of the instrument has begun.
The patent to Greenberg employs a clamp 70 at the distal end of the flexible member 60 through which, apparently, the laparoscope 10 must be threaded prior to use thereof (See col. 4, lines 28-33). In other words, the clamp 70 does not easily permit subsequent attachment to the laparoscope after the laparoscope has been positioned within the abdomen. In practice, however, it is very inconvenient to try to manipulate such an instrument, or a cystoscope or retractor, with extraneous equipment affixed to or near the proximal end, and invariably the surgeon or physician will first try to manipulate the instrument while it is unencumbered and then later try to clamp it into position, which apparently cannot be done with the Greenberg construction.
Other types of clamps having movable jaws have the tendency to crush or damage the instrument which it is trying to support, and this is especially likely when actions must be taken quickly. This leads to the damage or destruction of some very expensive instruments. In some cases clamps for such instruments can be used for instruments of only one diameter. Also, prior devices have limited degrees of movement or rotation. Patent literature showing such other clamps for surgical instruments and retractors include the patents to Grieshaber 3,040,739; Gauthier 3,384,077; Fackler 4,461,284 and LeVahn et al 4,617,916, but these constructions have not solved the aforementioned problems.
Other clamps have been designed for special purposes, such as for supporting tubular members without the necessity of using rotatable lever/movable jaw structures. For example, the U.S. Pat. Nos. 2,061,718 to Stahl; 2,482,625 to Kunkel; 4,616,384 to Lowell et al and 4,616,797 to Cramer all show adjustable clamps using spring-biased members to urge the device to be supported against or within a channel cavity. The Patents to Stahl, Cramer, and Lowell et al all require the use of turnable knobs or levers to aid in the manipulation of the clamp. The Kunkel clothes pin has a proximal jaw, spring-biased to the fully closed position relative to its distal jaw and must be urged open to accept a device to be clamped. These above-mentioned patents are neither designed nor suited for holding delicate and expensive surgical instruments.
No surgical instrument holder and clamp therefor has previously been available for holding cystoscopes or other endoscopic devices or surgical retractors that may be attached readily and locked or anchored in place after positioning relative to the patient, and which also may accommodate various sized instruments. There is a great need for a surgical holder having a clamp of greater versatility during endoscopic and surgical procedures, and which will allow for a firm but delicate grasp of fiber optic instruments and which will facilitate instrument rotation of 360 degrees along two axes.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to overcome disadvantages and deficiencies of the prior art, such as set forth above.
It is another object of the present invention to facilitate certain surgical and diagnostic procedures.
It is still another object of the present invention to provide an improved flexible holder for cystoscopes, other endoscopic devices, retractors, and the like.
It is a further object of the present invention to provide a flexible holder having a spring-biased clamping arrangement that works in a convenient manner.
It is yet another object of the present invention to provide a flexible holder having a clamp which will allow for a firm but delicate grasp of a cystoscope, retractor or the like.
It is still a further object of the present invention to provide a flexible holder for endoscopes and retractors having a clamp which may readily receive and stabilize an instrument after positioning of the instrument on or relative to a patient.
It is yet a further object of the present invention to provide a clamp for a flexible surgical holder having the ability to rotate 360 degrees upon two axes.
It is still a further object of the present invention to provide a clamp for a flexible surgical holder having an opensided configuration, the clamp being adapted to accommodate various sized cystoscopes or the like.
It is still another object of the present invention to provide a clamp for a flexible surgical holder which will permit users greater instrument versatility during endoscopic or surgical procedures.
It is still a further object of the present invention to provide a flexible surgical holder and clamp therefor which is relatively inexpensive to manufacture and which is especially easy and simple to manipulate.
Still other objects, features and attendant advantages of the present invention will become apparent to those skilled in the art from the following detailed description of certain exemplary embodiments constructed in accordance therewith, taken in conjunction with the accompanying drawings. The holder of the present invention is described at pp.105-6 of The Journal of Urology, Vol. 138, Jul.1987, incorporated herein by reference.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a surgical holder of the present invention supporting a cystoscope;
FIG. 2 is a perspective view of the surgical holder of the present invention, the holder being shown for supporting a surgical retractor;
FIG. 3 is a partial perspective view of the clamp employed in the surgical holder of the present invention, the clamp being shown as supporting the shaft region of a cystoscope;
FIG. 4 is a cross-sectional view of the clamp assembly employed in the present invention shown in FIG. 3 taken along line 4--4 in FIG. 3;
FIG. 5 is a cross-sectional view of the clamp assembly shown in FIG. 4 taken along line 5--5 in FIG. 4; and
FIG. 6 is an exploded elevational view of the clamp assembly of FIG. 3.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The presently preferred embodiment of the invention is shown in FIG. 1 of the drawings where a surgical holder 10 is shown to include a base rod 12,a flexible post 14, and a clamp assembly 16. The clamp 16 is shown holding a typical cystoscope 20 having an eyepiece 22, a control section 24 and a sheath or shaft 26. The base rod 12 of the holder 10 is attachable to an operating room table clamping assembly 18 provided with a vertical post 28, a cradle assembly 30, 34, and a screw adjustment knob 32, the cradle 34 being adapted to receive and hold the base rod 12 therein.
The base rod 12, generally of an elongated tubular configuration, is provided with a nut 36 at one end for receiving and mounting the flexible post 14. The nut is equipped with tightening lever 38 which in one position permits adjustment of the flexible post 14 to any position, thus allowing for three-dimensional movement. The base rod 12 is preferably formed of stainless steel material, but any suitable inert material may beemployed, such as aluminum or rigid heat-resistant plastic, so long as the material possesses smooth and rigid characteristics, can be heatsterilized, and presents no danger to the patient.
The flexible post 14 is equipped with a plurality of sections 40, suitably chrome-plated tubular steel, and precision ball joints 40a connected by aninternally-positioned flexible cable (not shown), suitably formed of steel.Movement of the lever 38 to a second position shortens the flexible internal cable and locks the flexible post 14 into its pre-set position. It should be understood that while the preferred embodiment of the presentinvention utilizes chrome-plated, tubular steel sections for the flexible post 14, it is possible to employ other materials as well. For example, the flexible post 14 could be formed of inert, heat resistant rigid plastic materials, such as polyacetal or polycarbonate resin or the like. The flexible post 14 is equipped at its distal end i.e. the end opposing the end attached to the base rod 12, with a nut/screw assembly 41 (See FIG. 3) securing the clamp assembly 16 thereto.
The clamp assembly 16 includes a C-shaped, open-sided member 48 for receiving the shaft 26 of the cystoscope 20 therein, a tubular housing 46,a head portion 44, and a tightening knob 42. The clamp assembly 16 permits 360 degree rotation of the cystoscope about an axis parallel to or concentric with the distal end of the flexible post 14, by rotation about the axis of a connecting stem 39 (see FIGS. 3 and 4). The clamp assembly members 42, 44, 46, 48 are preferably formed of stainless steel materials;however, it should be understood that other materials which are inert and heatsterilizable and possess sufficient strength and rigidity are also suitable, such as aluminum and certain plastic materials.
Referring now to FIG. 2 of the drawings, there is shown an identical or similar holder 10' compared to the holder 10 of FIG. 1. Here, however, theholder 10' is shown holding and positioning a surgical retractor 50 having a curved portion 52 at one end thereof. The holder 10' includes all the elements described above in relation to the holder 10 of FIG. 1, the device being supported by any suitable region of an operating table 72. Itshould be understood that the clamp assembly 16, more particularly the C-shaped member 48 which is spring-biased to the open position, can accommodate various retractors, cystoscopes or other instruments of different diameters with minimum manipulation required by a user by simplyturning the knurled knob 42.
Referring now to FIGS. 3-6 of the drawings, which illustrate the proposed clamping assembly 16 employed in the present invention, it is seen that the head portion 44 is provided with a central cavity 44a, a top centrallyaligned opening 44b which is in communication with the central cavity 44a, and a bottom centrally aligned opening 44c having a somewhat tapered or slanted or frustoconical wall 44d, the opening 44c also being in communication with the central cavity 44a. The wall 44d of the bottom opening 44c generally tapers outwardly and downwardly from the central cavity 44a toward the exterior of the head portion 44. Openings 44b and 44c and the central cavity 44ashould be in vertical longitudinal alignment, i.e. all should share the same longitudinal axis. It will be understood that the terms "top" and "bottom" refer to the attitude of the device as shown in FIGS. 3, 4 and 6, but that in use the clamp 16 may be oriented in other attitudes.
The tapered region 44d of the bottom opening 44c is adapted to receive a hollow tabular clamp housing 46 which includes a top plate 46c, having an integrally formed somewhat beveled wall 46a complementary in shape with, and recessed within, the frustoconical wall 44d of the head portion 44. The top plate 46c has a slot opening 46d extending therethrough. The tubular clamp housing 46 suitably has a diameter substantially equal to orless than the diameter of the bottom opening 44c of the head portion 44, sothat the clamp housing 46 may easily and snugly fit within the bottom opening 44c. The housing 46 is adapted to rotate about its axis relative to the head portion 44 by sliding movement between the tapered complementary surfaces 44c and 46a.
As best seen in FIGS. 4 and 6 of the drawings, the tubular housing 46 is adapted to receive within its hollow interior the C-shaped, open-sided member 48, which includes a C-shaped jaw portion 49 located along the longitudinal axis of the housing 46 and head portion 44, a central portion48a of reduced crosssection relative to the jaw portion 49, and a still smaller in cross-section threaded shaft portion 43a. The central portion 48a, which has two opposite flat walls 48d and projects in a fitting relationship through the slot 46d of the top plate 46a of the housing 46, is integrally disposed between the threaded shaft portion 43a and the jaw portion 49. A coiled spring 48b is also provided within the housing 46 about the central portion 48a with its top end bearing against the inside of the top plate 46c and its bottom end bearing against the top of the jawportion 49 along a ledge 48c. The coiled spring 48b thus urges the member 48 downwardly to an open position of the jaw 49. The C-shaped, open-sided jaw portion 49 is thus capable of receiving the sheath or shaft 26 of the cystoscope 20 (See FIG. 3), and indeed it should be understood that the C-shaped jaw 49 formed in portion 48 is capable of receiving various diameter-sized cystoscope or endoscope shafts, as long as the diameter of such a shaft does not exceed the space between portions 49a and 49b of thejaw 49.
As best illustrated in FIG. 6 of the drawings, the bottom of the tubular housing 46 includes a pair of circumferentially opposing notches 46e, onlyone of which is illustrated. These notches 46e aid in the clamping of the shaft 26 (See also FIG. 4) or the retractor 50 as in FIG. 2. Once a shaft has been inserted within the C-shaped region 49 and the device tightened as described below, the shaft is actually sandwiched between the lower portion of C-shaped region and the notches 46e, 46e located at the bottom end of the tubular housing 46. The inside clamping surfaces are shaped complementary to the shape of the instrument shaft being stabilized, so there is no problem of crushing or other damage to the instrument, while at the same time maintaining a good, solid clamping action.
The parts are assembled as shown in FIG. 6 with the member 48 being received within its housing 46 by positioning the coiled spring 48b about the central portion 48a (see particularly FIG. 4) and by inserting the entire structure longitudinally through the housing 46 as well as the headportion 44 and a stepped washer 42b. The threaded shaft portion 43a, once positioned within the top opening 44b of the head portion 44 and through the stepped washer 42b, is secured to the head portion 44 through the use of a screw adjustment knob 42 having a downwardly protruding tapered region 42a which is seated on the stepped washer 42b in the top opening 44b of the head portion 44. The upper end of the threaded shaft portion 43a is provided with an internally threaded countersink or bored out region 43b for receiving a conventional screw or bolt 43. The screw 43 acts as a stop for keeping the adjustment knob continually positioned on the threaded shaft 43a. The adjustment knob 42, which desirably has a knurled outer surface for easy grasping, is particularly easily used for closing the jaw 49 against the action of the spring 48b to hold the endoscope 26 or retractor 50 in place.
Referring now to FIGS. 3 and 6 of the drawings, the head portion 44 also includes the integrally formed annular projecting region or connecting stem 39 for receiving the distal end of the flexible post 14, which is easily secured through the use of a nut 41. As indicated above, the connecting stem 39 provides for a first 360° rotation about its axis of the clamp 16. Furthermore rotation of 360° is also providedabout the axis of the member 48 and the housing 46 moving as a unit by sliding motion between the beveled surfaces 44c and 46a, this second 360° rotation being about a second axis 90° from the first axis of rotation. Tightening of the clamp 48 about the instrument shaft 26, 50 does not tighten the housing 46 against the head portion 44, and consequently does not inhibit rotation about the second axis.
It should be understood that the holder and clamp assembly of the present invention is particularly useful for holding cystoscopes or other endoscopes or surgical retractors or the like even after these instrumentshave been positioned relative to the patient, and that this capability greatly facilitates manipulation by a surgeon or other physician. With theclamp biased in an open position and the instrument already positioned relative to the patient in the desired position, the holder is easily moved into position adjacent the shaft of the instrument and the instrument is moved sideways into the C-shaped region 49 where it is clamped by rotation of the knob 42. Because the size of the opening of theclamp is determined by the position of the knurled knob 42 along the lengthof the thread of the threaded shaft 43a, it will be understood that the size of the clamp opening when closed about the shaft or sheath 26 is finely controllable.
Moreover, the holder and clamp assembly is flexible and permits 360 degree rotation of the clamp assembly about two axes located at right angles to one another at the region where the clamping assembly is connected to the flexible post. The system is relatively simple and inexpensive to manufacture and requires little manual manipulation to use, this freeing the surgeon's or other physician's hands for other more important operations.
It will be obvious to those skilled in the art that various other changes and modifications may be made without departing from the scope of the invention and the invention is not to be considered limited to what is shown in the drawings and described in the specification. | A flexible holder and clamping assembly for adjustably holding cystoscopes or other endoscopic instruments and retractors or the like adjacent to or on an examination tables or the like is equipped with a unique clamping assembly which permits the holding of various sized instrument shafts. The clamping assembly is equipped with a vertically adjustable spring-biased C-shaped, open-sided region which is urged into a normally open position. The instrument shaft is, after positioning relative to the patient, slid sideways into the C-shaped jaw and retained between the jaw and a pair of circumferentially opposing notches of a tubular housing. The clamp also includes a head portion having various openings and a cavity for receiving the parts and connections of the clamping assembly. | 0 |
[0001] This application claims priority from U.S. Patent Application No. 60/365,547 filed on Mar. 20, 2002.
[0002] This invention relates to a computer aided system and method for visualizing flow in fluid carrying vessels in animal tissue and more particularly to a system and method for visualizing and identifying a direction of blood-flow in vessels supplying blood to a lesion, such as a neovascular lesion associated with age-related macular degeneration, to assist diagnosis and treatment of such lesions.
BACKGROUND OF THE INVENTION
[0003] Lesions are normally defined as an abnormal tissue structure located in an organ or other body part, and are often a manifestation of a harmful condition, disease or illness. Lesions may take many specific forms, such as choroidal neovascularizations (“CNVs”) which are found in the eye. In general, any abnormal vasculature in a body is a type of lesion.
[0004] A CNV is one manifestation of age related macular degeneration (“AMD”) and is a common cause of vision loss in people over the age of 50. In 1995, of the estimated 34 million people in the United States who were age 65 or older, approximately 1.7 million had some visual impairment resulting from AMD. Timely diagnosis and treatment of CNV is an important therapeutic objective because permanent vision loss can result if hemorrhage of the CNV occurs.
[0005] Visualization of the CNV
[0006] Visualization is a process of obtaining and viewing an angiographic image representation of the blood vessels in a region of interest following introduction of a visual enhancement material into such vessels.
[0007] Ordinarily, the choroidal vasculature of the eye cannot be readily visualized because the pigments in the retinal pigment epithelium (“RPE”) layer (sandwiched between the sensory retina and the choriocapillaris) and the pigments in the choroid do not readily transmit visible light wavelengths. Therefore, even sodium fluorescein angiography, routinely used to demonstrate the retinal vascular blood flow and whose excitation and emission spectra are comprised of visible wavelengths, shows only a faint diffuse flush resulting from vascular staining with fluorescein dye as it transits through the choroidal circulation and before dye enters the more superficial retinal vasculature.
[0008] Another methodology, termed indocyanine green (“ICG”) dye angiography (“ICGA”), is used for routinely visualizing choroidal blood flow. It is based on use of the near-infrared fluorescent light wavelengths emitted by ICG, which readily penetrate the pigmented ocular tissues. The impetus for developing ICGA about 30 years ago was to provide a tool for studying choroidal hemodynamics and blood flow physiology, but during the past 5 years, as a result of the equipment to implement it having became commercially available, its clinical use has become wide spread for detecting and monitoring AMD-associated CNV.
[0009] Visualizing and monitoring CNV blood flow has become an important part of diagnosing and treating CNV, especially when the lesions are directly beneath or immediately adjacent to the foveal area of the retina.
[0010] The commercial availability of the scanning laser ophthalmoscope (SLO) contributed to an increasing interest in ICGA. Compared to the predominantly available commercial ICGA systems based on fundus camera optics—capable of acquiring images at a rate of about one per second—the SLO afforded the ability to perform high-speed imaging. Ready access to high-speed ICG image acquisition systems was an important component of interest in a new AMD treatment modality, namely CNV feeder vessel photocoagulation treatment.
[0011] CNV Feeder Vessel Photocoagulation
[0012] A recent approach being pursued is so-called feeder vessel (“FV”) photocoagulation, wherein the afferent vessel supplying blood to the sub-foveal CNV is photocoagulated at a site outside the foveal area. So far, FV photocoagulation has proven to be an apparently effective treatment for CNVs, often resulting in improved visual acuity—a result not usually associated with other forms of treatment that have been used or considered to date. This treatment method is of particular interest for occult subfoveal CNV, for which there is no other treatment approach at this time.
[0013] As mentioned earlier, FVs are those vessels identified as supplying blood to an area of CNV. The length of these vessels are on the order of one-half to several millimeters long, and are thought to lie in Sattler's layer of the choroid (See: Flower R. W., Experimental Studies of Indocyanine Green Dye - Enhanced Photocoagulation of Choroidal Neovascularization Feeder Vessels , Am. J. Ophthalmol., 2000, 129:501-512; which is incorporated herein by reference). Note that Sattler's layer is the middle layer of choroidal vessels containing the arterial and venous vessels that feed and drain blood from the thin layer of choroidal capillary vessels lying just beneath the sensory retina. Following visualization of a CNV feeder vessel, e.g. by ICGA, photocoagulation of the feeder vessel is then performed in order to reduce or stop the flow of blood to the CNV.
[0014] Studies indicate often-dramatic resolution of the CNV-associated retinal edema and stabilization or even improvement in visual acuity, often within hours of feeder vessel photocoagulation.
[0015] A major drawback to FV treatment as currently practiced is that it is necessarily limited by the accurate identification and visualization of the FVs that supply blood to a given lesion. Thus, the success of both FV photocoagulation, and alternatives such as FV dye-enhanced photocoagulation (“DEP”), hinges on proper identification of the FVs. Conventionally, a single angiogram following single large ICG bolus injection are used to locate and identify feeder vessels. This single angiogram (one sequence of angiographic images) using conventional methods is insufficient to obtain proper blood flow data, thus necessitating the use of multiple angiographic sequences on the same eye. Furthermore, choroidal tissue staining produced by a single large dye bolus using conventional methods produces images of such poor contrast that accurate FV identification is difficult. Thus, after performing one angiogram, it is often necessary to perform a second angiogram in order to obtain a second set of angiographic images. This is often necessary because the first set of images is of insufficient quality to identify a FV. Thus, the parameters are adjusted for the second angiogram, based on the outcome of the first set of images, in order to acquire better quality images and thus adequate data about lesion blood flow. Accordingly, if the second set of angiographic images from the second angiogram is still inadequate for FV identification, a third angiogram must be performed. In addition, repeated angiogram studies result in declining contrast and image quality.
[0016] Even after obtaining technically adequate angiographic image sequences, sure identification of CNV FVs (as opposed to the draining vessels) is often difficult, especially when dye transits the FVs in pulsatile fashion and in the presence of significant background dye fluorescence from underlying choroidal vasculature. Under such circumstances, it is usually not possible to identify either specific feeder vessels or the direction of flow through them.
[0017] Current techniques for identifying and visualizing FVs are limited. A need therefore exists for, and it is an object of the present invention to offer, improved identification of feeder vessels and visualization of the direction of blood flow through vessels.
SUMMARY OF THE INVENTION
[0018] It is an objective of this invention to provide a system and method for visualizing fluid carrying vessels in animal tissue and more particularly to provide a system and method for visualizing and identifying a direction of blood-flow in vessels supplying blood to a lesion
[0019] Another objective of this invention is to significantly increase the frequency with which potentially treatable feeder vessels of a lesion can be detected. It is a further object of the invention to significantly increase the frequency with which potentially treatable feeder vessels of juxta- and sub-foveal age-related macular degeneration associated CNV can be detected.
[0020] The method of the invention is based on the premise that one can more readily identify FVs, and the visualization of dye through blood vessels is generally augmented by, serially displaying a series of angiographic images, of the dye flowing through the area of interest, repetitively, while being able to manipulate certain parameters in real-time. The serial display of images is generally referred to as phi-motion.
[0021] In accordance with one broad aspect of the present invention, there is provided a method for visualizing fluid flow through vessels having a visualizing composition flowing therethrough. The method comprises the following steps. Selecting from a sequence of angiographic images a subsequence of angiographic images. Reading a plurality of dynamic parameters, said dynamic parameters for controlling display of said angiographic images. Serially displaying said subsequence repetitively in accordance with said dynamic parameters. And providing an interface for dynamic user update of said dynamic parameters while displaying said subsequence. This method is referred to as Interactive Phi-Motion (“IPM”).
[0022] In one embodiment of the invention, dynamic parameters consisting of speed, interval, direction and pixel brightness are used and are dynamically adjustable. Preferably, the pixel brightness relationship, between collected and displayed intensity values, is represented by and manipulable through a Look-Up Table (“LUT”).
[0023] Also provided is an apparatus for carrying out the inventive method, a computer program product comprising a memory with code embodied thereon corresponding to the method, and a computer readable memory storing instructions corresponding to the method.
[0024] According to another broad aspect of the invention, a method is provided for treating a lesion with at least one blood vessel feeding blood to it. This method comprises: administering a visualizing composition comprising a fluorescent dye; capturing a plurality of angiographic images of a pre-selected area surrounding the lesion; visualizing the flow of said visualizing composition through said lesion using IPM; identifying said blood vessel; applying energy to said blood vessel, of a type and an amount sufficient to reduce the rate of blood flow through said blood vessel.
[0025] Advantageously, the methods of the present invention offer many benefits over conventional methods. First, by displaying the angiographic images in phi-motion and manipulating the dynamic parameters in real-time, visualization of the vessels of interest and the dye front entering and filling up the vessels can be optimized. Second, only one set of high-speed angiographic images need be taken, thus obviating the need to adjust parameters between captures in order to optimize visualization based on the previous angiogram. Third, by the ability to visualize the dye wavefront, the direction of flow in the vessel can be determined with certainty, thereby assuring that afferent and not efferent vessels are treated.
[0026] Still further advantages and benefits of the present invention will become apparent to those of ordinary skill in the art upon reading and understanding the following detailed description of the preferred embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] These and other features of the preferred embodiments of the invention will become more apparent in the following detailed description in which reference is made to the appended drawings wherein:
[0028] [0028]FIG. 1 illustrates, in flow chart form, a method of treatment of a blood vessel supplied lesion by photocoagulation incorporating the use of IPM.
[0029] [0029]FIG. 2 illustrates, in flow chart form, the method of IPM.
[0030] [0030]FIG. 3 illustrates the default LUT according to one embodiment of IPM.
[0031] [0031]FIG. 4 illustrates a modified LUT according to one embodiment of IPM.
[0032] [0032]FIG. 5 illustrates a second modified LUT according to one embodiment of IPM.
[0033] [0033]FIG. 6 illustrates a system overview diagram of a preferred embodiment of the diagnoses and treatment of a patient with an AMD-related CNV using IPM.
[0034] [0034]FIG. 7 illustrates a graphical user interface of a preferred embodiment of IPM.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0035] In the following description, numerous specific details are set forth to provide a thorough understanding of the invention. However, it is understood that the invention may be practiced without these specific details. In other instances, well-known processes have not been described or shown in detail in order not to obscure the invention. In the description and drawings, like numerals refer to like structures or and/or processes.
[0036] The methods of the present invention are claimed and described herein as a series of steps. It should be understood that these methods and associated steps may be performed in any logical order that preserves the spirit of the invention. Moreover, the methods may be performed alone, or in conjunction with other procedures and treatments administered before, during or after such methods and steps set forth herein without departing from the scope and spirit of the invention. Further, it is contemplated that the term animals as used herein includes, but is not limited to, humans.
[0037] Lesions, such as AMD-related CNV, have been shown to be successfully treated by photocoagulation or DEP of the blood vessel that feeds the lesion. Successful treatment, however, is predicated on the accurate and precise identification of the FV that supplies blood to the lesion. To this end, it is advantageous to both identify vessels that lead to the lesion and the direction of blood through that vessel, in order to determine whether it is a feeding (afferent) or draining (efferent) vessel. The possibility of achieving even more effective treatment of lesions, such as AMD-related CNV, lies in the improved visualization and identification of FVs using Interactive Phi-Motion prior to treatment. IPM provides improved visualization of dye flow through blood vessels, in a region of interest, by playing a subsequence of previously captured high-speed angiographic images repetitively, such as in a continuous loop, while providing the ability to dynamically manipulate certain parameters. By dynamically changing these parameters, one can find the precise combination of such parameters that will optimize the visualization of FVs for each given case. This is important as the degree to which these parameters need to be adjusted will vary with each set of angiograms, since visualization will vary depending on many variables, such as the specific patient, dose of the visualizing dye, speed at which the images were captured . . . etc.
[0038] Referring to FIG. 1, one broad aspect of the present invention provides a method for treating a lesion in an animal 100 . For the method to be effective, the lesion should further have a blood vessel that carries blood into the lesion. The inventive method includes, but is not limited to, the following steps. Performing high-speed angiography on the lesion 200 . Executing Interactive Phi-Motion 300 . Identifying the FV 400 . Photocoagulating the FV 500 . In a preferred embodiment of the invention, the method 100 is used to treat AMD related CNVs in humans.
[0039] High-speed angiography 200 is performed using any suitable visualizing composition and obtaining high-speed images showing the visualizing composition filling the vessels in the region of interest. Preferably, a CNV and its associated feeder vessels are visualized using Indocyanine Green Dye Fluorescence Angiography. ICG dye is administered to the subject intravenously and allowed to perfuse through the subject's vasculature. Visualization is preferably effected by irradiating the area of interest with a laser light of a type and in an amount sufficient to cause the ICG dye to fluoresce.
[0040] A preferred dosage of ICG, for visualizing FVs, is about 7.5 mg administered at a concentration of about 25 mg/ml in a volume of approximately 0.3 ml administered intravenously. Only one bolus is required per imaging sequence but multiple boluses may be employed. A concentration of about 0.025 mg/ml in blood theoretically produces the most fluorescence from the fundus of a mammalian eye. Additionally, in some embodiments of the invention, administration of ICG intravenously is followed by a 5 ml saline flush. The saline flush is used to rapidly push the bolus out of the cubital vein and into the vasculature within the thoracic cavity.
[0041] Activation of the dye is preferably effected using a laser light source in the range of about 780 nm-830 nm. When visualizing a CNV and its associated feeder vessels in a mammalian eye, the laser light used to excite the dye preferably irradiates a target site of about 1 cm 2 using about 20-100 mW of average power, although up to 230 mW can be used. Irradiation of the target area with laser light is preferably effected for about 10-20 seconds.
[0042] Capturing the sequence of high-speed images of the fluorescing vasculature can be accomplished by numerous means which are known and will be apparent to a person skilled in the art. Images are preferably captured as high-speed angiographic images on a CCD camera and stored in memory as one subject sequence. Using the preferred dosages above, high-speed images are typically recorded at a preferred rate of about 30 frames/sec for 10-20 secs in order to capture the fluorescence filling the vessel. According to this preferred embodiment of the invention, a typical subject sequence therefore is comprised of about 300 images.
[0043] While the above represents the preferred parameters for capturing high-speed angiographic images of a CNV, it is well known in the art that other dosages, light parameters and capture speeds are also effective to produce fluorescence in the eye such that the CNV and its associated feeder vessels can be visualized and angiographically captured.
[0044] Following the capture of high-speed angiographic images of the lesion and its associated FVs 200 , Interactive Phi-Motion 300 is then performed on the sequence of high-speed images. Phi-motion is a phenomenon first identified by Wertheimer in 1912, it refers to the visual perception of motion where none exists, like a cinematic. By utilizing phi-motion, in conjunction with dynamically manipulable parameters, IPM 300 allows for the subsequent improved identification and visualization of an FVs and most notably the direction of blood flow through the FV 400 .
[0045] Following identification of an FV suitable for treatment, photocoagulation of the vessel feeding the lesion is performed 500 . Targeting of the photocoagulation treatment beam is based upon the information previously derived from visualization and identification of the lesion and its associated FVs 400 through IPM 300 . Photocoagulation is effected by applying radiation of a kind and amount sufficient to effect an occlusion of the target vessel. It is believed that such occlusion occurs by increasing the temperature of the feeder vessel, resulting in either cauterization of the vessel or clotting of the blood within the vessel. As a result, the rate of blood flow through the vessel is reduced.
[0046] In a preferred embodiment of the invention, DEP is performed by previously injecting the subject with a radiation absorbing dye such as ICG dye. Photocoagulation is thus enhanced by utilizing the radiation absorbing properties of the ICG dye to perform dye enhanced photocoagulation of the FV. Preferably, an approximately 810 nm treatment laser is used at about 400-600 mW for about 1.0-1.5 seconds. This produces about 0.4J-0.9J of energy sufficient to photocoagulate the vessel in the presence of ICG.
[0047] The lesion is therefore attacked by cutting off the lesion's blood supply. This has the effect of starving the lesion and immediately reducing the hemodynamic pressure. Typical parameters for photocoagulation and DEP have been provided as preferred values and should not be construed as a limitation on the claims of the present invention
[0048] Referring to FIG. 2, another broad aspect of the present invention provides a method for visualizing blood flow through blood vessels using IPM 300 . IPM is comprised of the following steps. A subject sequence of previously captured high-speed angiographic images is retrieved 310 . Limits defining a sequential subsequence, representing the period of interest, are received 320 . Dynamic parameters are then received 330 . Once a run instruction is received 340 , the subsequence is displayed in phi-motion 350 until stopped 360 . During this display 350 , parameter changes 370 are dynamically updated 380 in response to changes, by a user, in said dynamic parameters.
[0049] The subject sequence is typically retrieved from memory in response to a user selecting a specific sequence identifier. The subject sequence of previously captured high-speed angiographic images which is retrieved 310 for IPM should contain the period of interest. Therefore, the sequence should show the dye front entering and filling up the vessels in the lesion. Typically, a subject sequence is selected by a user and retrieved from a memory means.
[0050] Limits representing a subsequence of the subject sequence is then received 320 . Typically, these limits are selected by a user by defining a frame and a number of frames surrounding, following or preceding the defined frame, or preferably, by defining a first and last frame. The subsequence should define the period, of interest, namely, the subsequence should contain that portion of the sequence that shows the visualizing dye entering the vessels, particularly the FV, associated with the lesion. The subsequence will be the only portion of the sequence undergoing IPM, thus, the longer the subsequence, the longer the IPM will take. Typically, using the preferred capture speeds and parameters above, about 30 frames are defined as the subsequence although any number of frames may be chosen depending on what the user wishes to visualize.
[0051] Following the defining of the subsequence, the dynamic parameters are received 330 . In a preferred embodiment of the invention, there are four dynamic parameters associated with IPM: speed, interval, direction and pixel brightness. The dynamic parameters can be updated in real time in response to user input at any time, including during the display in phi-motion.
[0052] The speed parameter defines the speed at which the angiographic images are displayed in phi-motion. Typically, the speed parameter is quantified in frames per second, one frame representing one angiographic image in the subsequence.
[0053] The interval parameter defines whether every image in the subsequence will be displayed. For example, in one embodiment of the invention, entering a value of two (2) will result in the display of every second image in the subsequence in phi-motion. The interval parameter may thus be adjusted to effect a display of every n th image (i.e. second, third, fourth . . . etc.) during phi-motion display.
[0054] The direction parameter defines the direction of the phi-motion display. In a preferred embodiment of the invention, the direction parameter can define running phi-motion in a continuous forward loop, continuous backward loop or continuous bounce. Selecting continuous bounce would result in a continuous display, in phi-motion, of the subsequence of angiographic images from first image to last image, last to first, first to last . . . etc.
[0055] The brightness parameter defines the relationship between collected intensity values and displayed intensity values. By manipulating the brightness parameter, pixels having a specific intensity on the collected angiographic image are adjusted to a different intensity on the phi-motion displayed angiographic image.
[0056] Referring to FIG. 3, in a preferred embodiment of the invention, the brightness parameter is received and adjusted by manipulation of a Look-Up Table. The x-axis represents the collected intensity value and the y-axis represents the displayed intensity value. Typically, by default, the brightness parameter is set so that the collected and displayed intensity values are directly proportional and represented by a linear line with a slope of one. In this example, there are three control points in the LUT. There are two control points at the opposite corners and one control point in the middle. By displacing the control points, the user can manipulate the relationship between collected and displayed intensity values. Referring to FIG. 4, the control point in the middle of line has been moved upwards in response to user manipulation, typically by clicking and dragging a pointing device. The new line, still fixed at opposite corners is now comprised of 2 line segments and defines a new and adjusted relationship between the collected and displayed intensity values. Referring to FIG. 5, new points may also be added by a user, such as by clicking a pointing device on part of the LUT, in order to further segment the line and further manipulate the relationship between collected and displayed intensity values. It is important to note that in this embodiment of the invention, it is not possible to move successive points on the line behind another, that is, to make the line double back in such a way that one collected intensity value corresponds to more than one displayed intensity value.
[0057] These parameters can be dynamically modified during phi-motion display in order to better visualize the blood flow through the region of interest. This allows for improved identification of a vessel feeding a lesion and visualization of direction of blood flow.
[0058] It will be apparent to those skilled in the art that additional parameters when adjusted dynamically during phi-motion, can be used in order to better visualize and identify feeder vessels and the direction of blood flow through them.
[0059] Upon receiving an instruction to start the display in phi-motion 340 , the angiographic images are displayed in phi-motion 350 . Display in phi-motion is effected by displaying the angiographic images of the defined subsequence in series and according to the dynamic parameters. In a preferred embodiment of the invention, the phi-motion is displayed in a display window on a monitor.
[0060] Changes to any of the dynamic parameters are detected 370 and updated 380 in real-time such that the phi-motion continues running. Therefore, by performing IPM, one can view the successive angiographic images displayed in phi-motion while dynamically changing parameters such as speed, interval, direction and pixel brightness in real-time.
[0061] Significantly, the present invention of IPM has several advantageous effects over and above conventional methods. First, by visualizing a dye filling up the vessels in a particular region in phi-motion, one can readily identify vessels in connection with the CNV and the direction of blood flow in them hence identifying the feeder (afferent) vessels as differentiated from the draining (efferent) vessels. Identification of FVs is essential to the success of photocoagulation as a treatment for lesions. Second, improved visualization and identification of FVs is accomplished by being able to manipulate the dynamic parameters in real-time while phi-motion display of the angiographic images continue to loop. Manipulation of these four parameters (speed, interval, direction and pixel brightness) dramatically improves the ability to visualize the dye entering the vessels in the region of interest and thus enhances FV identification. Finally, all the above is accomplished by obtaining one high-speed set of angiographic images. There is no need to take separate successive angiograms, possibly with multiple boluses, while trying to adjust the parameters between captures based on the previous angiogram set.
[0062] In another embodiment of the invention, sequential subtraction of images in the defined subsequence is effected prior to running the phi-motion in order to reduce noise. Sequential subtraction may be performed with registration which determines the amount of shift and rotation between successive images, allowing successive images to be aligned and thus optimizing sequential subtraction. In order to further reduce noise, a Fourier Filter can be effected on the subtracted images. Methods relating to sequential subtraction, registration and Fourier filtering, as is disclosed by U.S. Pat. No. 5,394,199 (which is hereby incorporated by reference), are well known in the art.
[0063] Referring to FIG. 6, there is shown an overall system overview diagram of a preferred embodiment of the invention incorporating the use of IPM 600 . In this embodiment, a subject's head 605 containing the subject's eye 610 is shown. An apparatus operationally disposed to capture high-speed images 620 is comprised of a viewing monitor 621 , a head mount 622 , a CCD camera 623 , a camera mount adaptor 624 , a modified fundus camera 625 , a camera positioning control 626 and a power and instrumentation cabinet 627 . A computer system 650 comprises a CPU 651 , memory 652 , such as a hard disk and random access memory, an imaging processor 653 , a PC monitor 654 and one or more input devices 655 .
[0064] In practice, the subject's eye 610 contains the lesion of interest, such as an AMD-related CNV. As such, the subject's eye is a candidate for treatment by photocoagulation of the FV of the CNV. The subject places his/her head 605 into the head mount 622 which can be adjusted to align the subject with the rest of the apparatus 620 . The camera positioning control 626 is used to adjust the modified fundus camera 625 in order to align the fundus camera 625 with the area of interest containing the CNV. This alignment is visualized using the viewing monitor 621 , which is mounted on the head mount 622 and displays the view through the fundus camera 625 .
[0065] Once the subject has been administered a visualizing dye such as ICG, the CCD camera 623 , mounted via a camera mount adaptor 624 , takes a series of high-speed angiographic images which are stored in memory 652 on computer system 650 . The conversion of analog images to digital form, both generally and through the use of imaging board buffers (i.e. EPIX™), are well known in the art. Each series of high-speed images are given a unique identifier such that it may be retrieved from memory 652 . Each image in a series is also given a unique identifier such that it may be retrieved from memory 652 .
[0066] A series of high-speed images are retrieved from memory 652 , pursuant to a request by a user through one or more input devices 655 , and displayed on the PC monitor 654 using image processor 653 . The computer system 650 , contains an operating system capable of performing run-time operations. A computer program is stored in memory 652 which, when executed by the CPU 651 , is comprised of instructions corresponding to the method of IPM 200 . The user defines a subsequence to undergo IPM via input devices 655 . Dynamic parameters are defined using one or more input devices 655 . In response to a start signal by the user through an input device 655 , the CPU 651 displays the subsequence in phi-motion, pursuant to the dynamic parameters, on the PC monitor 654 using image processor 653 . Dynamic parameters are updated by the CPU 651 during phi-motion.
[0067] Referring to FIG. 7, a graphical user interface (“GUI”) 700 of one embodiment of the invention is shown. The GUI 700 is displayed on the PC monitor 654 . The GUI 700 comprises a display window 780 , a corresponding slider bar 785 , a LUT display 790 , a stored sequence window 710 , a phi-motion segment window 715 , a treatment image window 740 , a start phi-motion button and a store phi-motion subset button.
[0068] The display window 780 displays images in the stored sequence. The display window 780 also displays the subsequence in phi-motion when the phi-motion display is running. The slider bar 785 is used select individual angiographic images in the stored sequence or subsequence to be displayed. The LUT display 790 is the interface used by the user to manipulate the relationship between collected and displayed intensity values for the phi-motion subsequence referred to with respect to FIGS. 3 - 5 . The default relationship between collected and displayed intensity values, namely a directly proportional relationship, can be restored by selecting a reset transfer function button 792 . Control points may be added to the LUT by right clicking a mouse on an LUT line segment within the LUT display 790 . Control points may be removed by selecting a remove control point button 793 . Control points are automatically removed in the reverse order of their placement. Upon removal, addition or adjustment of each control point, the LUT is re-calculated with the modified points.
[0069] The stored sequence window 710 numerically displays the first and last frame numbers in the stored sequence. The phi-motion window 715 comprises the following areas in which user may input limits and parameters. The phi-motion subsequence is defined by a first and last image and by inputting the corresponding frame numbers into first 720 and last 725 image boxes in the phi-motion segment window 715 . The speed parameter is entered in a speed parameter box 730 in frames per second. The interval parameter is entered in an interval parameter box 735 . The direction parameter is defined by selecting an appropriate direction button, forward 751 , reverse 752 , or bounce 753 .
[0070] Phi-motion display can be initiated by selecting the start phi-motion button 760 , and a phi-motion subsequence with accompanying parameters may be saved to memory 652 by selecting the store phi-motion subset button 770 .
[0071] Treatment images may be manipulated by using the treatment image window 740 . An individual treatment image may be marked with a marker by selecting a mark/select image button 741 and using the mouse to click on the treatment image displayed in the display window 780 . The most recently added marker may be removed by selecting the remove last marker button 742 . An individual treatment image may be stored in memory 652 by selecting a store treatment image button 743 . Finally, a user may exit the program by selecting an exit button 800 .
[0072] Although the invention has been described with reference to certain specific embodiments, various modifications thereof will be apparent to those skilled in the art without departing from the spirit and scope of the invention as outlined in the claims appended hereto. | A method for visualizing fluid flow through vessels having a visualizing composition flowing therethrough, the method comprising the steps of: selecting from a sequence of angiographic images a subsequence of angiographic images, reading a plurality of dynamic parameters, the dynamic parameters for controlling display of the angiographic images, serially displaying the subsequence repetitively in accordance with the dynamic parameters, and providing an interface for dynamic user update of the dynamic parameters while displaying the subsequence. | 0 |
CROSS REFERENCE TO RELATED CO-PENDING APPLICATIONS
[0001] This application claims the benefit of U.S. provisional application Ser. No. 60/750,520 filed Dec. 14, 2005 and entitled “SPINOUS PROCESS FIXATION IMPLANT”, the contents of which are expressly incorporated herein by reference.
[0002] This application is also a continuation of U.S. application Ser. No. 11/609,418 filed on Dec. 12, 2006 and entitled SPINOUS PROCESS FIXATION IMPLANT the contents of which are expressly incorporated herein by reference.
FIELD OF THE INVENTION
[0003] The present invention relates to a system and a method for spinal stabilization through an implant, and more particularly to spinal stabilization through attachment of the implant to the spinous processes along one or more vertebras.
BACKGROUND OF THE INVENTION
[0004] The human spine comprises individual vertebras 30 (segments) that are connected to each other to form a spinal column 29 , shown in FIG. 1 . Referring to FIGS. 1B and 1C , each vertebra 30 has a cylindrical bony body (vertebral body) 32 , three winglike projections (two transverse processes 33 , 35 and one spinous process 34 ), left and right facet joints 46 , lamina 47 , left and right pedicles 48 and a bony arch (neural arch) 36 . The bodies of the vertebrae 32 are stacked one on top of the other and form the strong but flexible spinal column. The neural arches 36 are positioned so that the space they enclose forms a tube, i.e., the spinal canal 37 . The spinal canal 37 houses and protects the spinal cord and other neural elements. A fluid filled protective membrane, the dura 38 , covers the contents of the spinal canal. The spinal column is flexible enough to allow the body to twist and bend, but sturdy enough to support and protect the spinal cord and the other neural elements. The vertebras 30 are separated and cushioned by thin pads of tough, resilient fiber known as inter-vertebral discs 40 . Disorders of the spine occur when one or more of the individual vertebras 30 and/or the inter-vertebral discs 40 become abnormal either as a result of disease or injury. In these pathologic circumstances, fusion of adjacent vertebral segments may be tried to restore the function of the spine to normal, achieve stability, protect the neural structures, or to relief the patient of discomfort.
[0005] Several spinal fixation systems exist for stabilizing the spine so that bony fusion is achieved. The majority of these fixation systems utilize rods that attach to screws threaded into the vertebral bodies or the pedicles 48 , shown in FIG. 3C . In some cases plate fixation systems are also used to fuse two adjacent vertebral segments. This construction usually consists of two longitudinal plates that are each placed laterally to connect two adjacent pedicles of the segments to be fused. This system can be extended along the sides of the spine by connecting two adjacent pedicles at a time similar to the concept of a bicycle chain. Current plate fixation systems are basically designed to function in place of rods with the advantage of allowing intersegmental fixation without the need to contour a long rod across multiple segments. Both the plating systems and the rod systems add bulk along the lateral aspect of the spine limits access to the pars and transverse processes for decortication and placement of bone graft. In order to avoid this limitation many surgeons decorticate before placing the rods, thereby increasing the amount of blood loss and making it more difficult to maintain a clear operative field. Placing rods or plates lateral to the spine leaves the center of the spinal canal that contains the dura, spinal cords and nerves completely exposed. In situations where problems develop at the junction above or below the fused segments necessitating additional fusion, the rod fixation system is difficult to extend to higher or lower levels that need to be fused. Although there are connectors and techniques to lengthen the fixation, they tend to be difficult to use and time consuming.
[0006] Accordingly, there is a need for a spinal stabilization device that does not add bulk to the lateral aspect of the spine and does not limit access to the pars and transverse processes for decortication and placement of bone graft.
SUMMARY OF THE INVENTION
[0007] In general, in one aspect, the invention features an implantable assembly for stabilization of spinous processes including a k-shaped component comprising an elongated plate and top and bottom deformable plates extending at first and second angles from a first surface of the elongated plate, respectively, thereby defining first and second spaces between the elongated plate and the top and bottom deformable plates and a compression element configured to compress and move the first and second deformable plates toward the elongated plate and to change the first and the second angles, respectively. The first and second spaces are configured to receive first and second spinous processes, respectively. Moving the first and second deformable plates toward the elongated plate results in engaging the first surface of the elongated plate and first surfaces of the top and bottom deformable plates with lateral surfaces of the first and second spinous processes, respectively.
[0008] Implementations of this aspect of the invention may include one or more of the following features. The compression element includes a plate placed on top of the top and bottom deformable plates and a bolt configured to pass through concentrically aligned through-bore openings formed in the center of the plate, the top and bottom deformable plates and the center of the elongated plate. The bolt comprises a head having a diameter larger that the diameter of the plate's through-bore and an elongated body having threads formed at a portion of the elongated body, the threads being dimensioned to engage inner threads in the elongated plate's through-bore. Tightening the bolt engages the bolt threads with the inner threads in the elongated plate's through-bore and compresses the head onto the plate and the plate onto the deformable top and bottom plates, causing them to move toward the elongated plate. The first surface of the elongated plate faces the first surfaces of the top and bottom deformable plates and all first surfaces comprise protrusions configured to engage and frictionally lock the elongated plate's first surface and the deformable top and bottom plates' first surfaces onto the lateral surfaces of the first and second spinous processes. The may be teeth, spikes, serrations, rough coatings or ridges. The assembly may further include a top locking member configured to lock the elongated plate's top end and the top deformable plate's top end. The top locking member includes a long bolt configured to be threaded through bolt holes formed through the top deformable plate's end, the first spinous process and the elongated plate's top end. The top locking member may be staples, cables, sutures, pins or screws. The assembly may further include a bottom locking member configured to lock the elongated plate's bottom end and the bottom deformable plate's bottom end. The bottom locking member comprises a long bolt configured to be threaded through bolt holes formed through the bottom deformable plate's bottom end, the second spinous process and the elongated plate's bottom end. The bottom locking member may be staples, cables, sutures, pins or screws. The elongated plate, the top and bottom deformable plates and the compression element may be made of stainless steel, titanium, gold, silver, alloys thereof, absorbable material, non-metal materials including synthetic ligament material, polyethylene, extensible materials or combinations thereof. The elongated plate and the top and bottom deformable plates may have adjustable lengths.
[0009] In general, in another aspect, the invention features a method for stabilizing spinous processes, including providing a k-shaped component having an elongated plate and top and bottom deformable plates extending at first and second angles from a first surface of the elongated plate, respectively, thereby defining first and second spaces between the elongated plate and the top and bottom deformable plates and a compression element configured to compresses and move the first and second deformable plates toward the elongated plate and to change said first and said second angles, respectively. Next, placing first and second spinous processes within the first and second spaces, respectively, and then compressing and moving the first and second deformable plates toward the elongated plate via the compression element, thereby engaging lateral surfaces of the first and second spinous processes onto the elongated plate's first surface and the first and second deformable plates' first surfaces, respectively.
[0010] Among the advantages of this invention may be one or more of the following. The assembly stabilizes vertebras by attaching plates to the spinous processes of the vertebras. This stabilization device does not add bulk to the lateral aspect of the spine and does not limit access to the pars and transverse processes for decortication and placement of bone graft.
[0011] The details of one or more embodiments of the invention are set forth in the accompanying drawings and description below. Other features, objects and advantages of the invention will be apparent from the following description of the preferred embodiments, the drawings and from the claims
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Referring to the figures, wherein like numerals represent like parts throughout the several views:
[0013] FIG. 11A is a side view of the human spinal column;
[0014] FIG. 1B is an enlarged view of area A of FIG. 1A ;
[0015] FIG. 1C is an axial cross-sectional view of a lumbar vertebra;
[0016] FIG. 2 is a posterior view of a portion of the spine with a first embodiment of a spinous process fixation implant according to the present invention affixed thereto;
[0017] FIG. 3 is a top view of the spine with the spinous process fixation implant of FIG. 2 affixed thereto;
[0018] FIG. 4 is a front side view of the spinous process fixation implant of FIG. 2 ;
[0019] FIG. 5 is a back side view of the spinous process fixation implant of FIG. 2 ;
[0020] FIG. 6 is a right side perspective view of the spinous process fixation implant of FIG. 2 ;
[0021] FIG. 7 is partially exploded right side perspective view of the spinous process implant of FIG. 2 ;
[0022] FIG. 8 is a left side perspective view of the spinous process fixation implant of FIG. 2 ;
[0023] FIG. 9 is a top perspective view of the spinous process fixation implant of FIG. 2 ;
[0024] FIG. 10 is an exploded right side perspective view of the spinous process fixation implant of FIG. 2 ;
[0025] FIG. 11 is a front side view of the elongated component 110 of FIG. 2 ;
[0026] FIG. 12 is a back side view of the elongated component of FIG. 2 ;
[0027] FIG. 13 is a front side view of the top pivoting component of FIG.2 ;
[0028] FIG. 14 is a front side view of the bottom pivoting component of FIG. 2 ;
[0029] FIG. 15 is a front side view of a second embodiment of a spinous process fixation implant according to the present invention, depicting the top and bottom pivoting components in the closed position;
[0030] FIG. 16 is a front side view of the spinous process fixation implant of FIG. 15 with the top and bottom pivoting components in the open position;
[0031] FIG. 17 is a left side perspective view of the spinous process fixation implant of FIG. 15 , depicting the top and bottom pivoting components in the closed position;
[0032] FIG. 18 is a left side perspective view of the spinous process fixation implant of FIG. 15 , depicting the top and bottom pivoting components in the open position;
[0033] FIG. 19 is an exploded left side view of the spinous process fixation implant of FIG. 15
[0034] FIG. 20A is a right side view of the elongated plate component 210 of FIG. 15 ;
[0035] FIG. 20B is a right side view of the top pivoting component 220 of FIG. 15 ;
[0036] FIG. 20C is a right side view of the bottom pivoting component 230 of FIG. 15 ;
[0037] FIG. 21 is a front side view of a third embodiment of a spinous process fixation implant according to the present invention, depicting front and back pivoting components in the closed position around the spinous processes;
[0038] FIG. 22A depicts insertion of the spinous process fixation implant of FIG. 21 from the side with front and back pivoting components in the open position;
[0039] FIG. 22B depicts pivoting the front and back pivoting components of FIG. 21 to close them around the spinous processes;
[0040] FIG. 23 is a front side view of the embodiment of a spinous process fixation implant according of FIG. 21 , depicting front and back pivoting components in the closed position and locked position around the spinous processes;
[0041] FIG. 24 is a front side view of a fourth embodiment of a spinous process fixation implant according to the present invention, depicting front top , front bottom and back pivoting components in the closed position around the spinous processes;
[0042] FIG. 25A is a front side view of the front top pivoting component of the spinous process fixation implant of FIG. 24 ;
[0043] FIG. 25B is a front side view of the front bottom pivoting component of the spinous process fixation implant of FIG. 24 ;
[0044] FIG. 25C is a front side view of the back pivoting component of the spinous process fixation implant of FIG. 24 ;
[0045] FIG. 26 is a front side view of the locking component of the spinous process fixation implant of FIG. 24 ;
[0046] FIG. 27 is a front side view of a fifth embodiment of a spinous process fixation implant according to the present invention, depicting front and back pivoting components in the closed and locked position around the spinous processes;
[0047] FIG. 28 depicts cutting and opening paths A and B around superior and inferior adjacent spinous processes;
[0048] FIG. 29 depicts inserting back pivoting component of the spinous process fixation implant of FIG. 27 along path A of FIG. 28 ;
[0049] FIG. 30 depicts inserting front pivoting component of the spinous process fixation implant of FIG. 27 along path B of FIG. 28 ; and
[0050] FIG. 31 is a front side view of a sixth embodiment of a spinous process fixation implant according to the present invention, depicting a single K-component body.
DETAILED DESCRIPTION OF THE INVENTION
[0051] The present invention relates to a system and a method for a spinous process fixation implant.
[0052] Referring to FIG. 2 , FIG. 3 , and FIG. 4 , a spinous process fixation assembly 100 stabilizes two adjacent vertebras 92 , 94 of the human spine by engaging and locking their spinous processes 90 a and 90 b, respectively. Spinous process fixation assembly 100 includes an elongate plate 110 and top and a bottom pivoting plates 120 , 130 , located opposite to plate 110 and configured to form a K-shaped structure together with plate 110 . Top and bottom pivoting plates 120 , 130 pivot around axis 140 (shown in FIG. 6 ) independent from each other, forming angles 162 , 164 with plate 110 , respectively. The pivoting motion of plates 120 , 130 along directions 144 a, 144 b and 146 a, 146 b, moves them close to or away from the elongated plate 110 , as shown in FIG. 4 . Elongated plate 110 has a body 112 and front and back cross plates 114 , 116 , extending at right angle to the front of the body 112 and back of the body 112 , respectively, as shown in FIG. 10 , FIG. 11 and FIG. 12 . Body 112 has a top end 113 a, a bottom end 113 b, an outer surface 118 and an inner surface 117 . Axis 140 passes through apertures 152 and 154 formed in the centers of the cross plates 114 , 116 , respectively, as shown in FIG. 11 and FIG. 12 . Cross plates 114 , 116 extend between the bottom surface and top surface of the adjacent spinous processes 90 a, 90 b, respectively and have edges 115 which are rounded and sculpted to correspond to the geometry of the spinous processes 90 a , 90 b and lamina around which they will fit once implanted. Cross plates 114 , 116 are substantially flat, parallel to each other and a gap is formed between them sized to hold portions of the top and bottom pivoting plates 120 , 130 , as shown in FIG. 7 .
[0053] Referring to FIG. 10 , FIG. 13 and FIG. 14 , top pivoting plate 120 has a main body 122 with top and bottom ends 123 a , 123 b , respectively and inner 127 and outer surface 128 , respectively. An arm 124 extends downward from the bottom end 123 b of the body 122 and a side plate 128 extends at right angle to the back of the body 122 . The arm 124 has an aperture 126 located at the bottom left corner and extends from the front side to the back side of the arm 124 . Similarly, bottom pivoting plate 130 has a main body 132 with top and bottom ends 133 a , 133 b ,respectively, and inner and outer surfaces 137 , 138 respectively. An arm 134 extends upward form the top end 133 a and has an aperture 136 at the top left corner, extending from the front side to the back side of the arm 134 , as shown in FIG. 10 , and FIG. 14 . A side plate 138 extends at right angle from to the back of the body 132 . All edges of plates 110 , 120 , 130 are rounded to prevent damage of the adjacent tissue during implantation or spinal movement. Plates 110 , 120 , 130 are made of stainless steel, titanium, gold, silver, alloys thereof, absorbable material, non-metal materials including synthetic ligament material, polyethylene, extensible materials or combinations thereof. Plates 110 , 120 , 130 may have adjustable lengths. In one example plates 110 , 120 , 130 have lengths of 30 mm, 15 mm, 15 mm, respectively, and the assembly may have a width between 3 mm to 10 mm.
[0054] Referring to FIG. 7 , a long bolt 180 passes through apertures 152 and 154 of the cross plates 114 , 116 of the elongated plate 110 and though apertures 126 and 136 formed in the top and bottom pivoting plates 120 , 130 , respectively. Bolt 180 has a head 181 , a shaft 183 and threads 184 formed on the end portion of the shaft 183 . Threads 184 engage threads in the aperture 154 of the back cross plate 116 , in order to hold and secure the three components 110 , 120 , 130 , of the assembly 100 together. In other embodiments, a nut (not shown) is attached at the end of the bolt 180 to hold and secure the three components 110 , 120 , 130 , of the assembly 100 together. In other embodiments bolt 180 is threaded into the cartilage between the two vertebras to secure the three components 110 , 120 , 130 together and to attach the assembly 100 onto the spine. The inner surfaces 117 , 127 , 137 of plates 110 , 120 , 130 , respectively, have protrusions 111 that grab and frictionally engage the sides of the spinous processes 90 a , 90 b , as shown in FIG. 3 , FIG. 11 , FIG. 13 and FIG. 14 . Protrusions 111 may be teeth, serrations, ridges, and other forms of rough surfaces or coatings that produce rough surfaces. The position of pivoting plates 120 , 130 relative to each other and relative to plate 110 is locked with a set screw 182 passing trough the aperture 156 formed in the upper right corner of the front cross plate 114 . Tightening of the setscrew 182 locks the front and back cross plates 114 , 116 to the pivoting plates 120 and 130 . Engaging and locking the spinous process fixation assembly 100 onto spinous processes 90 a , 90 b , prevents the components 110 , 120 and 130 from moving sidewise or up and down toward or away from each other during spinal movement.
[0055] The assembled spinous process fixation assembly 100 is implanted into the patient with the use of instrumentation (not shown) between the two adjacent spinous processes 90 a , 90 b , as shown in FIG. 2 . The cross plates 114 , 116 are placed between the spinous processes 90 a , 90 b so that the body 112 of the elongated plate 110 and the top and bottom pivoting plates 120 , 130 fall on the lateral sides of the spinous processes 90 a , 90 b . One spinous process 90 a lies between the top portion of the body 112 and the top pivoting plate 120 , as shown in FIG. 3 , and the other spinous process 90 b lies between the bottom portion of the body 112 and the bottom pivoting plate 130 , with their inner surfaces 117 , 127 , 137 facing the lateral surfaces of the spinous processes 90 a , 90 b . On each of the inner surfaces 117 , 127 , 137 of the plates 110 , 120 , 130 , respectively, the protrusions 111 face toward the lateral surface of the adjacent spinous process. At this point, the top and bottom pivoting plates 120 , 130 are pivoted as necessary to provide the desired fit of the plates to the spinous processes. The bolt 180 is tightened, clamping the protrusions 111 into the surfaces of the spinous processes and locking the three plates relative to each other by engaging the threads of the aperture 154 . The protrusions 111 and the threading of the bolt into aperture 154 of the back cross plate 116 frictionally secures the spinous process fixation assembly 100 onto the spinous processes 90 a , 90 b and helps prevent the device from shifting or slipping.
[0056] Referring to FIG. 15 , FIG. 16 , FIG. 17 , FIG. 18 , in a second embodiment of the spinous process fixation assembly 200 , the top and bottom pivoting plates 220 , 230 are designed to pivot past each other and to form any angle with the elongated plate 210 between 0 and 180 degrees. In particular, plates 220 and 230 pivot to a 90 degree angle relative to plate 210 and form a sidewise oriented T, shown in FIG. 16 and FIG. 180 . The assembly 200 of FIG. 16 , with the pivoting plates 220 , 230 at a 90 degree angle with the plate 110 , is inserted sidewise between the top and bottom spinous processes 90 a , 90 b . Once the assembly is inserted, the plates 220 and 230 are pivoted upward and downward, respectively, and are placed at angles relative to the plate 210 necessary to provide the desired fit of the plates to the spinous processes. Sidewise implantation of the assembly 200 has the advantage of reduced trauma in the area between the spinous processes.
[0057] In this embodiment the top pivoting plate 220 has a main body 222 with top and bottom ends 223 a , 223 b , respectively and inner 227 and outer surface 228 , respectively, shown in FIG. 19 , FIG. 20 . Main body 222 has a width 229 dimensioned to allow plate 220 to pivot past plate 230 when placed in the gap 219 between the two cross plates 214 , 216 of plate 210 . An arm 224 extends downward from the bottom end 223 b of the body 222 . The arm 224 has an aperture 226 located at the center of the bottom end of the arm and extends from the front side to the back side of the arm 224 . A protruding annulus 225 surrounds aperture 226 and projects outward form the back side of the arm 224 . Annulus 225 is dimensioned to fit within aperture 254 of the back cross plate 216 . Aperture 226 includes inner threads (not shown) extending from the front to the back side of the arm 224 . Similarly, bottom pivoting plate 230 has a main body 232 with top and bottom ends 233 a , 233 b ,respectively, and inner and outer surfaces 237 , 238 respectively. Main body 232 has a width 239 dimensioned to allow plate 230 to pivot past plate 220 when placed in the gap 219 between the two cross plates 214 , 216 of plate 210 . An arm 234 extends upward form the top end 233 a and has an aperture 236 located at the center of the top end of the arm and extends from the front side to the back side of the arm 234 , as shown in FIG. 19 and FIG. 20C .
[0058] Elongated plate 210 , top pivoting plate 220 and bottom pivoting plate 230 are assembled together, as shown in FIG. 18 . Annulus 225 is inserted in the aperture 254 of the back cross plate 216 and the apertures 252 , 236 , 226 of the front cross plate 214 , bottom pivoting plate 230 and top pivoting plate 220 , respectively, are aligned. A long bolt 280 is inserted through the aligned apertures and threaded in the inner threads of the aperture 226 . The position of pivoting plates 220 , 230 relative to each other and relative to plate 210 is locked with a set screw 282 passing trough the aperture 256 formed in the upper left corner of the front cross plate 214 . Tightening of the set screw 282 locks the front and back cross plates 214 , 216 to the pivoting plates 220 and 230 . Once assembly 200 is implanted into the patient between the two adjacent spinous processes 90 a , 90 b , the assembly is secured and locked in position, according to the process described above.
[0059] Referring to FIG. 21 , in a third embodiment the spinous process fixation assembly 300 includes a front S-shaped plate 310 and a mirror image back S-shaped plate 320 connected at their centers via a bolt 380 forming an X-shaped structure. The front S-shaped plate 310 pivots relative to a back S-shaped plate 320 around pivot point 340 and the spinous process 90 a of the top vertebra 92 is frictionally engaged between the upper arms of S-plates 310 and 320 , while the spinous process 90 b of the bottom vertebra 42 is frictionally engaged between the lower arms of S-plates 310 and 320 . A bolt 380 is threaded through apertures formed in the centers of the front and back S-plates, as shown in FIG. 21 . The inner surfaces of the upper and lower arms of the S-shaped plates are sculpted to fit the shape of the spinous processes and have protrusions that frictionally engage the sides of the spinous processes and together with the bolt 380 securely lock the assembly 300 between the spinous processes 90 a , 90 b.
[0060] Assembly 300 , with the S-shaped plates 310 , 320 assembled and oriented horizontally, as shown in FIG. 22A , is inserted sidewise between the top and bottom spinous processes 90 a , 90 b . Once the assembly is inserted, plates 310 and 320 are pivoted upward and downward, respectively, as shown in FIG. 22B , and they assume a vertical orientation so that their corresponding inner surfaces surround spinous processes 90 a , 90 b . Sidewise implantation of the assembly 300 has the advantage of reduced trauma in the area between the spinous processes.
[0061] Long bolts 370 may be added to this embodiment to further anchor the assembly 300 on the spinous processes. If they are added, appropriately sized holes must be drilled laterally through the spinous processes prior to placement of the device. Once the device is in place as described above, one long bolt 370 is threaded through a bolt hole on the top end of plate 310 , through the drilled hole in the spinous process 90 a , then out through a bolt hole on top end of plate 320 . A second long bolt 370 may also be threaded through a bolt hole on the bottom end of plate 310 , through the drilled hole in the spinous process 90 b , then out through a bolt hole on the bottom end of plate 320 . Tightening of bolts 380 and 370 securely locks the assembly 300 around spinous processes 90 a , 90 b.
[0062] In another embodiment of the spinous process fixation assembly 400 , shown in FIG. 24 , the front S-shaped plate include a top pivoting component 410 , shown in FIG. 25A , and a bottom pivoting component 420 , shown in FIG. 25B , forming the top and bottom portions of the S-curve, respectively. The back S-plate 430 is formed as one component S-shaped plate with a curved top portion 432 , a bottom curved portion 434 and a rounded center 438 having an aperture formed in its center 436 , shown in FIG. 25C . The top pivoting component 410 includes an upward extending curved portion 412 and a lower rounded end 414 having an aperture 416 formed in its center. The bottom pivoting component includes a downward extending curved portion 422 and an upper rounded end 424 having an aperture 426 formed in its center. The front and back surfaces of the rounded end 424 , the back surface of the rounded end 414 and the front surface of the rounded center 438 have radial extending grooves 425 , shown in FIG. 25B and FIG. 25C . Grooves 425 define one-degree arcs, thus allowing the plates 410 , 420 , 430 to rotate relative to each other by one degree steps. Assembly 400 further includes a block 440 dimensioned to fit between the adjacent spinous processes 90 a , 90 b and having top and bottom edges configured to correspond to the geometry of the spinous processes 90 a , 90 b and lamina around which they will fit once implanted. Different sized blocks are used to accommodate different spacings between adjacent spinous processes 90 a , 90 b . The front and back surfaces of block 440 also include grooves 425 around an aperture 446 formed n the center of the block. The top pivoting plate 410 , bottom pivoting plate 420 , block 440 and the back plate 430 are arranged so that their corresponding apertures 416 , 426 , 446 , 436 are aligned and a bolt 480 is threaded through these apertures. Once the assembly 400 is inserted, the plates 410 and 420 are pivoted upward and downward, respectively, and are placed so as to surround the spinous processes. The inner surfaces of the upper and lower arms of the S-shaped plates are sculpted to fit the shape of the spinous processes and have protrusions that frictionally engage the sides of the spinous processes and together with the bolt 480 securely lock the assembly 400 between the spinous processes 90 a , 90 b.
[0063] Long bolts 370 may be also added to this embodiment to further anchor the assembly 400 on the spinous processes, as was described above. Alternatively, a staple 450 may be placed on the top and bottom open ends of the plates 410 , 420 and 430 , as shown in FIG. 27 . In other embodiments banding, cabling or suturing may be used to attach the ends of plates 410 , 420 and 430 to the spinous processes. The outer surfaces of the plates 410 , 420 and 430 may be rounded, as shown in FIG. 24 or straight, a shown in the embodiment 500 of FIG. 27 .
[0064] Referring to FIG. 28 , FIG. 29 and FIG. 30 , the process of implanting the spinous process fixation assembly between two adjacent vertebrae includes the following steps. First an incision is made in the patient's back and paths A and B are opened along bony planes 95 and through ligaments 96 between the adjacent spinous processes 90 a , 90 b . Path B is mirror image of path A about the centered sagittal plane 98 . Next, the back component 510 of the assembly of FIG. 27 is inserted along path A, as shown in FIG. 29 , and the ends 513 a and 513 b are attached to the spinous processes 90 a , 90 b , respectively. Next, the front component 520 is inserted along path B and a bolt 580 is threaded through the apertures 512 , 522 formed in the centers of back and front components 510 , 520 , respectively. The front and back components are pivoted around the axis passing through their central apertures 512 , 522 , so that their ends 513 a , 523 a , 513 b , 523 b surround and close around the spinous processes 90 a , 90 b . The ends 513 a , 523 a , and 513 b , 523 b are then attached to spinous processes 90 a , 90 b , respectively as shown in FIG. 30 . The ends may be attached with any of the above mentioned methods including frictional engagement of protrusions, long bolts, staples, cabling, banding or suturing. Plates 510 , 520 are dimensioned so when assembled, assembly 500 has a width 535 that covers and protects the spinal cord after laminectomy or facectomy.
[0065] In a sixth embodiment, shown in FIG. 31 , spinous process fixation assembly 600 includes one K-shaped component having an elongated plate 610 and two deformable plates 620 , 630 extending upward and downward, respectively, from the center 615 of the elongated plate. A top gap 612 is formed between the top portion of the elongated plate 610 and the upward extending plate 620 . A bottom gap 614 is formed between the bottom portion of the elongate plate 610 and the downward extending plate 630 . The K-shaped assembly is placed between the adjacent spinous processes 90 a , 90 b , as shown in FIG. 31 , and a plate 640 is placed in the center of the assembly 600 on top deformable plates 620 , 630 . A bolt 680 is threaded through apertures formed in the center of plate 640 and the center 615 of the K-shaped component, as shown in FIG. 31 . Tightening of the bolt 680 down applies pressure onto the plate 640 , which is transferred to the top and bottom deformable plates 620 , 630 . Plates 620 , 630 move closer to plate 610 and the widths of the top and bottom gaps 612 , 614 is reduced, resulting in engaging protrusions 111 formed on the inner surfaces of plates 610 , 620 , 630 with the spinous processes 90 a , 90 b and tightening of the plates 620 , 630 and 610 around the spinous processes 90 a , 90 b . The ends of the plates 620 , 630 may be further attached to the spinous processes with any of the above mentioned methods including long bolts, staples, cabling, banding or suturing.
[0066] Other embodiments are within the scope of the following claims. For example, vertebras 92 and 94 may be any two vertebras, including lumbar L1-L5, thoracic T1-T12, cervical C1-C7 or the sacrum. The fixation assembly 100 may extend along multiple vertebras. The K shaped structure may be also configured as a mirror image of the structure in FIG. 2 , with the pivoting plates 120 , 130 located on the left side and the elongated plate 110 located on the right side of the FIG. 2 . The elongated plates 110 , 220 and the top and bottom pivoting plates 120 , 220 , and 130 , 230 of the embodiments of FIG. 4 and FIG. 15 , respectively, may have adjustable lengths. Similarly, S-plates 310 , 320 of the embodiment of FIG. 21 and plates 410 , 420 , 430 of the embodiment of FIG. 24 may have adjustable lengths. Similarly, elongated plate 610 and deformable plates 620 , 630 of the embodiment of FIG. 31 may have adjustable lengths. The main bodies 122 , 132 of pivoting plates 120 , 130 may be detached from the corresponding extending arms 124 , 134 . Bodies 122 , 132 may be attached to the extending arms 124 , 134 via hinges (not shown) which allow them to swing open and close for better placement around the corresponding spinous processes 90 a , 90 b.
[0067] Several embodiments of the present invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. Accordingly, other embodiments are within the scope of the following claims. | An implantable spinous process fixation device includes a k-shaped component comprising an elongated plate and top and bottom deformable plates extending at first and second angles from a first surface of the elongated plate, respectively, thereby defining first and second spaces between the elongated plate and the top and bottom deformable plates and a compression element configured to compress and move the first and second deformable plates toward the elongated plate and to change the first and the second angles, respectively. The first and second spaces are configured to receive first and second spinous processes, respectively. Compressing and moving the first and second deformable plates toward the elongated plate results in engaging the first surface of the elongated plate and first surfaces of the top and bottom deformable plates with lateral surfaces of the first and second spinous processes, respectively. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This application relates generally to apparatus and methods of purifying and storing water produced from atmospheric air and more particularly an apparatus and method to effectively purify and store water produced from atmospheric air by use of heat and hygroscopic material.
2. Description of the Related Art
Water production systems that generate water from atmospheric air produce water that is generally free of the chemicals and minerals found in tap or bottled water. This feature is viewed favorably by most advocates of the water from air systems, but the lack of residual disinfectant chemicals pose a problem of growth of pathogens and algae in the stored water. Since these systems depend on the introduction of ambient air which is not sterile for the production of water and since the water is stored in the system until used by the consumer, special techniques must be employed to ensure that the water and the water storage systems remain free of pathogens and algae for years with very little maintenance. Likewise, the absence of minerals like calcium and sodium result in water that tastes “flat” so the system must introduce adequate and safe amounts of the minerals required to provide pleasant tasting water.
SUMMARY OF THE INVENTION
One embodiment of the invention includes an apparatus for producing, purifying and storing potable water from air comprising the following:
a) a closed air passageway containing purified air; b) an open air passageway containing filtered ambient air where the input filter is carbon impregnated with silver; c) a rotating mass of hygroscopic material comprising a portion of the mass in fluid contact with the closed air passageway, another portion of the mass in fluid contact with the open air passageway, adapted to periodically move each portion of the mass through both passageways wherein all portions will alternately pass from one air passageway into another air passageway, each portion of the mass alternating between a hydrated state and a dehydrated state; d) a heating unit in fluid contact with the purified air comprising a heating element, a temperature sensing unit and a controller, the controller having at least two temperature setpoints, one setpoint for normal water production operations and another setpoint for decontamination of the air in the closed air passageway; e) a condensing unit comprising one or more condensing coils with inside surfaces and outside surfaces, the inside surfaces in fluid contact with the purified air, the outside surfaces in fluid contact with the ambient air; f) a water collecting unit in fluid contact with the inside surfaces of the condensing coils comprising a tank for collection of condensation from the condensing coils and further comprising an ultraviolet radiation unit for destruction of microorganisms in the condensation where the radiation unit provides periodic ultraviolet irradiation of water collected by the condensing unit and provides additional irradiation of the water for a period of 10 to 60 minutes before the water is transferred out of the water collecting unit; g) a water purification and storage unit comprising a collection of refillable chambers containing filter material suitable for use with potable water such as zinc activated zeolite, a mineral pi for introduction of minerals into the water, an input opening in fluid contact with the water collecting unit or the adjacent refillable chamber and an output opening connected to either the input for the next refillable chamber or a collapsible, disposable water storage unit and; h) a computer control system to monitor and control the water production process and notify the user of required maintenance for the apparatus.
Another embodiment of the invention includes a method of purification of water produced from ambient air by use of hygroscopic material and a condensing unit comprising the steps of:
a) using a closed air passageway containing rechargeable air for absorption of water vapor from a mass of hygroscopic material and disgorgement of water in a condensing unit, where the rechargeable air has no direct fluid contact with the ambient air; b) periodically decontaminating the hygroscopic material, condensing unit, closed air passageway and rechargeable air by raising the temperature inside the closed air passageway to in excess of 88 degrees C. for at least 15 minutes; c) using a disposable pure water reservoir; d) irradiating the water collected by the condensing unit periodically with ultraviolet irradiation; e) irradiating the water collected by the condensing unit with ultraviolet radiation for a period of 10 to 60 minutes before transferring the water to the disposable pure water reservoir; f) using a zinc or silver activated zeolite filter to control the microbial contamination of water in the disposable pure water reservoir; g) controlling the water production process and notifying the user of required maintenance with a computerized control system and; h) using an ambient air input filter of carbon impregnated with silver to remove particulate matter and pathogens from the ambient air.
BRIEF DESCRIPTION OF THE DRAWINGS
So that the manner in which the above recited features, advantages and objects of the present invention are attained and can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to the embodiments thereof which are illustrated in the appended drawings.
It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
FIG. 1 illustrates the closed air passageway and the open air passageway and those elements that are contained within these passageways in this embodiment of the invention.
FIG. 2 illustrates the water collection and storage subsystem for one embodiment of the invention.
DETAILED DESCRIPTION OF EMBODIMENTS
Generating and storing potable water produced from atmospheric air by means of a mass of hygroscopic material (sometimes referred to as molecular sieve or desiccant) requires a multistep approach to achieve pleasant tasting water that remains free of contaminants and pathogens until the delivery of the water to the user. In these systems, atmospheric water vapor, which is water created by evaporation, is condensed into liquid form and stored until used. The water produced is generally free of inorganic impurities, including minerals essential for providing the pleasant taste of “pure water” but can often contain pathogens and contaminants that are introduced into the water generation system from the ambient air.
Minerals to provide pleasant tasting water can be introduced into the condensate in a variety of ways by dissolving fixed, safe amounts of the essential minerals. Of course, taste is subjective, so there is no one formula for a mixture of minerals and pure water that will satisfy all consumers of the water. But generally, studies have shown that pure water mixed with trace amounts of calcium and sodium will be safe for human consumption and will provide the pleasant taste that will satisfy most consumers.
Keeping the water free of pathogens is a more vexing problem. Pathogens will be present in the atmospheric air which is an essential component of systems that produce water by means of hygroscopic material. The atmospheric air and the airborne pathogens will be passed through the hygroscopic material with the ambient air, so contamination of the system is inevitable.
Proper filtration of the ambient air can significantly reduce the airborne pathogen density, but the introduction of some live pathogens from the ambient air will occur. Once in the system, a moist, warm environment will likely encourage the growth of the pathogen population.
In addition to filtering the ambient air before drawing it into the system, the pathogen population can be kept under control by utilizing a separate air chamber for absorption of water from the atmospheric air. In this manner, most of the pathogens that survive the ambient air filter will be carried out of the system by the ambient air without coming into contact with the air that is used to extract the moisture from the hygroscopic material in a closed-air chamber.
Periodic decontamination of the hygroscopic material and the closed-air chamber by raising the temperature of that chamber to temperatures above 88 degrees Centigrade for up to 15 minutes will also keep the pathogen population in check. This same technique can be used to periodically sterilize the inside of the condensation unit, so the water collected will contain few pathogens.
Water stored in the collection tank can be exposed to ultraviolet radiation to eliminate pathogen growth in the collection tank in accordance with well documented procedures for radiation frequencies, levels, time of exposure and distance of the water from the radiation source. Likewise, ultraviolet radiation can be used to sterilize the water before it is moved into the final storage tank/delivery system.
Water moved from a collection tank to the final storage tank is passed through a series of filters that can function both as devices to introduce the minerals into the water as described above and also to remove pathogens or other particulate matter. Cartridges of activated carbon have proven to be effective as filter material. An additional stage or an additional filter cartridge is used to introduce trace amounts of residual antimicrobial material. For this stage, zinc or silver activated zeolite has shown to be effective for providing long term antimicrobial residual effect. Methods to ensure that the user will periodically replace the filter cartridges will safeguard against a filter system that has become ineffective with age.
Finally, utilization of a disposable, collapsible plastic bag for the final storage tank will help reduce the pathogen population in the delivered water by periodic disposal of a tank that may have become contaminated. Also, a flexible storage bag minimizes extra air in the storage tank that can encourage growth of aerobic pathogens common in water delivery systems.
In the following, reference is made to embodiments of the invention. However, it should be understood that the invention is not limited to specific described embodiments. Instead, any combination of the following features and elements, whether related to different embodiments or not, is contemplated to implement and practice the invention. Furthermore, in various embodiments the invention provides numerous advantages over the prior art. However, although embodiments of the invention may achieve advantages over other possible solutions and/or over the prior art, whether or not a particular advantage is achieved by a given embodiment is not limiting of the invention. Thus, the following aspects, features, embodiments and advantages are merely illustrative and are not considered elements or limitations of the appended claims except where explicitly recited in a claim(s). Likewise, reference to “the invention” shall not be construed as a generalization of any inventive subject matter disclosed herein and shall not be considered to be an element or limitation of the appended claims except where explicitly recited in a claim(s).
FIG. 1 is an illustration of an apparatus for producing, purifying and storing potable water from air according to one embodiment of the invention. FIG. 2 illustrates the water collection and storage subsystem for an embodiment of the invention. The illustrations depict the elements of this apparatus generally. Some of the details that may be essential to the apparatus, but the depiction of which will not further the discussion of this particular embodiment of the invention have been left out of the illustration. For instance, the wiring harnesses showing electrical paths for control and power to the electrical components of the apparatus have been omitted to simplify the illustration.
Referring to FIGS. 1 and 2 , the housing of this embodiment of the invention includes two air chambers. In the closed air chamber ( 1 ) where air is forced by a fan at the rate of 50 to 150 cubic feet per minute ( 2 ) through controllable heating elements ( 3 ) that raise the air temperature to 75-82 degrees C. This air is then passed through the portion of the mass of rotating hygroscopic material ( 9 ) that has been saturated with moisture. The hot air forces the hygroscopic material to release the trapped water into the air in the closed air chamber in the form of water vapor. This moisture-laden air is then passed through the interior of the condenser coils ( 5 ). Once each day, the computer control system ( 16 ) changes the heater setpoint temperature to in excess of 88 degrees C. for a period of 15 or more minutes to decontaminate that portion of the mass of hygroscopic material that is in the closed air chamber, plus the air and the interior of the chamber and the interior of the condenser coils ( 5 ).
The condenser coils ( 14 ) are a collection of copper tubes extending through a seal in the closed air chamber into the open air chamber ( 4 ). In the open air chamber, the ambient air (from outside the unit) is forced through a charcoal filter impregnated with silver ( 13 ) over the exterior of the condenser coils by a fan ( 13 ) at the rate of 580-1000 cubic feet per minute, cooling the coils and the moisture laden air in the interior of the condenser coils, causing condensation on the interior of the coils.
After the ambient air in the open air chamber is forced over the condenser coils, it is passed through that portion of the hygroscopic material ( 8 ) that has been dehydrated in the closed air chamber before being discharged through a vent ( 18 ) in the housing. The dehydrated portion of the hygroscopic material then absorbs moisture from the ambient air so that as it rotates, the newly hydrated portion of the hygroscopic material will move into the closed air chamber. In this manner, the process of transferring the moisture from the open ambient air chamber to the closed air chamber will proceed in a continuous fashion.
Water that condenses on the inside of the condenser coils drips into the collection tank ( 6 ). The water collected in the tank is irradiated by a submerged ultraviolet light ( 7 ) used to destroy most of the pathogens that might be introduced into the system. The ultraviolet light source provides irradiation of the water with 9 watts of electromagnetic radiation for 10 to 20 minutes every hour.
The ultraviolet light ( 7 ) is controlled by a computer control system ( 16 ) that also monitors the water level in the collection tank ( 10 ) and the final storage tank ( 11 ). The control system also controls the pump ( 17 ) used to move the water from the collection tank, through the filters ( 10 ) to the disposable water reservoir ( 11 ). Prior to activating the pump to transfer the water out of the collection tank, the computer control system will irradiate the water in the collection tank with the ultraviolet light ( 7 ) for 20 minutes.
Water that is pumped out of the collection tank is passed through one or more filters ( 10 ). The filter enclosures allow for quick replacement of the filter cartridge and mineral pi contained within. The filtration cartridge contains activated carbon and zinc or silver activated zeolite to remove any remaining contaminants and pathogens in the water and to provide some residual antimicrobial effect. The mineral pi consists of a solid pellet that will deliver 40 milligrams of calcium and sodium for each liter of water that passes over it.
Water that is passed through the filters flows into the disposable water reservoir ( 11 ) if the reservoir is not full. This reservoir is made of flexible plastic to allow it to collapse or expand as the volume of water in the reservoir diminishes or increases. This inexpensive storage reservoir is easily replaced to minimize the risk of extensive pathogen populations in the reservoir. Typical replacement cycle is 3 to 6 months. Water is dispensed through a spigot ( 15 ) attached to the reservoir.
The disposable water reservoir rests on a peltier plate ( 12 ) to lower the temperature of the stored water before dispensing. Two different cold water dispensing temperatures are provided, −3 to 6 degrees C. and 7 to 9 degrees C.
Further modifications and alternative embodiments of various aspects of the invention will be apparent to those skilled in the art in view of this description. Accordingly, this description is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the general manner of carrying out the invention.
It is to be understood that the forms of the invention shown and described herein are to be taken as examples of embodiments. Elements and materials may be substituted for those illustrated and described herein, parts and processes may be reversed, and certain features of the invention may be utilized independently, all as would be apparent to one skilled in the art after having the benefit of this description of the invention. Changes may be made in the elements described herein without departing from the spirit and scope of the invention as described in the following claims. | Embodiments of the invention include a system and a method for purifying and storing water produced from atmospheric air to provide a safe, inexpensive source of potable water. Improvements over prior systems and methods include the use of two isolated air chambers, one for ambient air used to capture moisture from the atmosphere, and another for clean rechargeable air to convert the captured moisture into condensate and using a rotating mass of hygroscopic material and a condensation unit, each of which is periodically sterilized by heat. | 2 |
TECHNICAL FIELD
This invention relates to a material treating method and apparatus, and more particularly to a method and a device for heat treating of solvent-extracted meals or flakes, including oilseed meals. The process and device are also applicable to the thermal treatment of other materials and to materials containing solvent or other liquids adhering thereon.
BACKGROUND OF THE INVENTION
By way of example and for the purpose of illustration, the invention will be described herein in connection with solvent-extracted soybean oilseed meal.
In U.S. Pat. No. 2,585,793, there is set forth a process in which solvent-extracted meal containing solvent or other liquid such as water is heated below the boiling-point of water, steam being introduced into the meal to condense on the meal and bring the moisture content of the meal into the range of about 12 to 30% by weight. Thereafter the meal is cooked at a temperature usually above the boiling-point of the water to produce a so-called toasted meal.
In the practice of the known process, the solvent-saturated meal or flakes are withdrawn from the extractor and passed through jacketed agitator equipment serving as a desolventizing means.
The solvent vapors are withdrawn and the meal or flakes substantially free of solvent are passed for further treatment.
In such a process, it was found that, at best, only a small amount of the steam employed could be introduced into lower compartments of the desolventizer, because, when a large volume of steam was employed in the lower compartments, flakes of the meal were carried from the topmost compartment together with the solvent vapors and some steam into the solvent vapor condenser.
It has further been suggested to utilize a so-called pre-desolventizing screw or other device, sometimes called a "SCHNECKEN" or PDS, which is placed between the solvent extractor (SE) and the desolventizer unit (DS) to pre-evaporate a certain percentage of solvent adhering on the meal before conveying the meal into the desolventizer. Such a pre-desolventizer is normally operated by indirect steam either with the aid of steam-heated plates or a steam-jacket forming the walls of the apparatus. The solvent adhering on the meal is partly vaporized and vented from the upper portion of the pre-desolventizer to a condenser via a vapor-washer to prevent meal-flakes entering the condenser.
Though a large portion of the solvent adhering on the meal is rapidly and positively eliminated in the PDS, there is considerable waste of the heat energy employed to vaporize a portion of the solvent in the pre-desolventizing station. Part of this energy leaves the PDS as the heat of vaporization in the solvent vapor discharged. Part of this energy is lost as a result of the superheat of these vapors. The temperature of the solvent vapors is far above the boiling temperature and ranges between about 85 and 100 degrees C. as compared to the nominal boiling range of the solvent (often hexane or its azeotrope, for example) of about 60 to 69 degrees C. at atmospheric pressure.
Furthermore, there is never a dust-free solvent vapor suitable for being recovered. This makes it necessary to install voluminous equipment downflow from the pre-desolventizer, and often downflow from the desolventizer, for washing and filtering the solvent vapors exiting these equipments. As a result, the size and amounts of equipment of the plant are significantly increased, as are the costs for auxiliary energy and maintenance.
SUMMARY OF THE INVENTION
It is a first object of the invention to provide an improved method and device for removing adhering solvents from solvent-extracted solids, which device will effectively filter dust from the solvent vapors evolved in the pre-desolventizer and the desolventizer so as to provide a dust-free recovered solvent.
Another object of the invention is to provide an improved process and device for removing solvent adhering to solvent-extracted solids from a continuous solvent extraction system whereby live steam is employed as the main evaporating agent for the solvent and for moisturizing solids for toasting.
Another object of the invention is to provide an improved process and device for removing solvent adhering to extracted solids from a continuous solvent extraction system followed by drying and toasting the solvent-free solids, wherein a two-step desolventizing is employed. The first or pre-desolventizing stage operates with the aid of indirect steam heating and the second stage or desolventizing step operates with the aid of live steam, thereby recovering solvent vapors which are completely free of solid impurities such as dust or meal-flakes.
Another object of the invention is to provide an improved process and method for desolventizing solids and preparing the solids for toasting in a single, continuous operation without intermediate handling of the solvent vapors vaporized from the solids whereby a very compact and controllable apparatus is used, and wherein the steam consumption is at a minimum, and the solvent being recovered is in a state wherein a high percentage of dust has been removed.
According to the present invention, the solid material leaving the solvent extractor is freed from adhering solvent in a two-stage process, the first stage (i.e. the pre-desolventizer stage) rendering solid material of which the adhering solvent is reduced by from 10 to 80% by weight based on the amount of solvent when leaving the solvent extractor. The remaining portion of solvent is completely removed by vaporization in the desolventizer stage.
The pre-desolventizer operates with the aid of indirect steam heating, e.g. by heat exchange through the steam-jacketed wall or hollow platelike equipment.
A pre-desolventizer suitable for the performance of the invention is known as the "Schnecken" which is a screw conveyor having a double-wall steam heated screw and/or a steam-jacketed wall. Other suitable apparatus for the pre-desolventizing stage are steam-jacketed paddle conveyors, rotary dryers, flat tray cookers, and the like.
Though any suitable desolventizer such as disclosed in the U.S. Pat. Nos. 2,585,793 (Kruse), 2,695,459 (Hutchins), 2,776,894 (Kruse), 3,018,564 (Kruse, et al.), 3,367,034 (Good) or 3,392,455 (Kingsbaker et al.) may be employed in the second stage of the process of the invention (desolventizing stage), the particular apparatus envisioned as being employed is of the kind disclosed in the European Patent Application No. 70496 (Schumacher) published Jan. 26, 1983 (U.S. application Ser. No. 399,995).
It has been found that the consumption of steam per weight-unit of solvent containing solid material to free the solid material from the solvent can be considerably diminished and the purity of solvent vapors vented off the desolventizing stage can be greatly improved if, in accordance with this invention, the hot solvent vapors leaving the pre-desolventizer at a temperature of between about 85 and 100 degrees C. are directly (i.e. without passing a filtering, washing and condensing system) vented through suitable insulated ducts into the desolventizer. The excess heat energy in the superheated solvent vapors is, thereby, transmitted to the partly desolventized solids in the desolventizer.
Preferably, the hot solvent vapors coming from the pre-desolventizer are introduced into a compartment within the desolventizer upwardly disposed within that equipment but below the uppermost compartment thereof. The floors of the compartments above the one into which hot solvent vapors are introduced can be porous so that the vapors will pass therethrough and into contact with the meal in the compartment or compartments above the one into which the vapors are introduced. Vaporization of solvent adhering to the solid material during its passage through the desolventizer will, thereby, be effected by the hot solvent vapors passing therethrough. Additionally, as the hot solvent vapors pass upwardly within the desolventizer through the porous floor or floors of upwardly disposed compartments, particulate matter entrained in the solvent vapors during vaporization in the pre-desolventizer will be filtered by the partly desolventized solid meal in the various compartments through which the solvent vapors pass upwardly.
The combined solvent vapors leaving the top of the desolventizer and being vented to a condenser and distillation unit are highly devoid of particulate matter and require no washing or any other cleaning operation for removal of fines.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic flow diagram of a process in accordance with the present invention for heat treating flowable material in which the hot solvent vapors from the pre-desolventizer are directly introduced into the desolventizer.
FIG. 2 is a more detailed schematic flow diagram of the same process in which the hot solvent vapors from the pre-desolventizer are introduced underneath the uppermost compartment of the desolventizer. The desolventizer can be a combined desolventizing and drying unit as described in European Patent Application No. 70496.
DETAILED DESCRIPTION OF THE INVENTION
The process depicted in FIG. 1 and FIG. 2 is one developed for the heat treatment of solvent-extracted soybean oil meal, but the process is also applicable without any essential alterations to other solids having adhered solvent to be vaporized.
Referring to FIG. 1, in the solvent extraction unit, the soybean meal 1, which is preferably in the form of flakes coming from the mill, is subjected to a suitable solvent 2 for the removal of the soybean oil.
Oil laden solvent 3 is withdrawn at the bottom of the solvent extraction system and sent to a recovery still for the separation of the solvent from the oil. The preferred solvent is hexane.
The solvent laden meal, preferably in flaked form, is removed from the extractor with the aid of a conveyor 4, which may be a screw conveyor, an "en masse" conveyor, or any other suitable means, and is discharged into the top of the pre-desolventizer wherein between about 10 and 80% by weight of the solvent adhering on the flakes is vaporized by indirect steam heating.
The solvent vapors having an average temperature in the range of between about 85 degrees C. and 100 degrees C. are vented through conduit 8 directly into the desolventizer where they are introduced below the uppermost compartment.
The desolventizer is also steam heated. Usually only about 5 to 15% by weight of the total steam required, however, is indirect steam being supplied via steam jackets, double bottoms between the various compartments, agitator shaft, etc., while the remaining 85 to 95% by weight of the steam is live steam being introduced via conduit 7 into the lowermost compartment of the desolventizer.
The partly desolventized flakes are removed from the pre-desolventizer by, for example, screw conveyor, "en masse" conveyor or any other suitable conveyor means 5 and discharged into an upwardly disposed compartment of the desolventizer.
In the desolventizer, live steam, in condensing, gives off its latent heat of vaporization and this is imparted to the meal flakes and solvent adhering thereto, so that almost all of the remaining solvent (in an order from about 95% by weight to about 99% by weight) is vaporized very quickly and passes via duct 9 to a condenser where the almost dust-free solvent is condensed outside of the desolventizer.
When passing the upper compartment or compartments of the desolventizer, the solvent vaporized from the partly desolventized flakes in the lower part of the desolventizer combines with the superheated solvent vapors coming from the pre-desolventizer via duct 8.
Any dust in the solvent vaporized in the pre-desolventizer is filtered off in passing through the flakes in the uppermost compartment or compartments of the desolventizer.
Because of heat exchange between the hot solvent vapors from the pre-desolventizer and those from the desolventizer, there is no solvent vapor condensation within the upper portion of the desolventizer.
The desolventized meal is discharged from the bottom compartment of the desolventizer through discharge device 6, which may be a screw conveyor or other feed device regulated to discharge the same quantity of meal as is being fed into the top compartment of the unit. As a result, a relatively constant volume of meal can be maintained in the desolventizer.
The embodiment of the invention illustrated in FIG. 2 is similar to that illustrated in FIG. 1 and demonstrates in greater detail the joint operation of a continuous operating "Schnecken" or screw-type pre-desolventizer and a desolventizer which is similar to the system disclosed in the European Patent Application No. 70496 (Schumacher) published Jan. 26, 1983 (U.S. application Ser. No. 399,995).
The solvent-saturated soybean flakes are continuously withdrawn from the solvent extractor SE through line 14 and passed into the Schnecken-system PDS which, as shown, may consist of one or more horizontally disposed steam jacketed tubes (for example, four) 60, 61, 62, 63 communicating in series and being disposed one above the other. It will be understood that configuration of the tubes in parallel is within the scope of the invention.
The solvent laden flakes are conveyed from tube 60 to tube 61, 62, 63 whereby radiant heat removes from 10% to 80% by weight of the solvent by vaporization. The vaporized solvent leaving the pre-desolventizer has an average temperature of between about 85 and 100 degrees C.
The pre-desolventized flakes are withdrawn from the bottom tube 63 and passed by the aid of a conveyor 15, elevator 25 and a further conveyor 16 into the top compartment of the vertically positioned vapor desolventizer DS.
In the preferred embodiment of the invention the desolventizer DS, which may act as a combined desolventizer-dryer or a desolventizer-toaster-dryer, consists of cylindrical chamber with a centrally inserted rotary shaft 20 which serves to effect horizontal movement of a number of agitators or sweep arms. The latter move over the bottoms of compartments 70, 71, 72 and 73 at a slight distance from the surface of said bottoms to maintain the meal or flakes in adequate mixing motion and keep the flakes as loose as possible.
The flakes pass through suitable bottom discharge means from compartment 70 to compartment 73 (of which not less than two nor more than six compartments are usually provided, depending on the operating conditions and the plant capacity), while, simultaneously, live steam enters through conduit 17 and is distributed through the lower-most bottom to rise upwardly in a direction opposite that in which the meal moves.
As indicated in FIG. 2 the bottoms between the various compartments (with the exception of the lowermost bottom) are provided with holes or perforations uniformly distributed over their entire area in order to ensure a uniform distribution of the live steam. The bottoms 11, 12 and 13 between the compartments 70, 71, 72 and 73 consist of two plates enclosing a steam space which is connected to a supply for steam so that the interior volume of the double-bottoms can be adjusted to the temperature required in the desolventizing process.
It is understood that each individual bottom may have steam admitted thereto separately or may be connected to a common steam source.
The flakes having reached the lowermost compartment 73 are discharged by way of conduit 93 which is preferably a screw conveyor or any other suitable conveyor means. The flakes leaving the plant via conduit 93 are free of solvent and may be conveyed to a drying apparatus if the desolventizer itself does not produce a dry enough material.
Returning to the pre-desolventizer (PDS), the solvent vaporized by radiation heat produced by the action of steam-heated jackets around the tubes 60-63 is vented from each tube to the desolventizer DS with the aid of suitable conduits discharging the superheated solvent vapors into manifolds 34 and 30 from which the superheated solvent vapors are fed into the DS preferably underneath the bottom 11 in compartment 71.
As shown in FIG. 2, the manifold 30 is provided with three outlet conduits extending horizontally into the compartments 71, 72 and 73 of the desolventizer DS. Each conduit is equipped with a suitable valving system 31, 32 and 33 allowing the distribution of superheated solvent vapors to the corresponding compartments 71, 72 and 73.
As has been said before, preferably the entire amount of superheated solvent vapors coming from the pre-desolventizer PDS via manifolds 34 and 30 is supplied through open valve 31 (valves 32 and 33 being closed) into compartment 71 via conduit 17. However, in certain circumstances, it may be appropriate to introduce a minor portion of superheated solvent vapors into other compartments of the desolventizer DS below compartment 71 (for example, into compartment 72 via conduit 18 or even into compartment 73).
This would be appropriate in cases where the amount of dust in the flakes to be treated is extremely high and, therefore, cannot be completely filtered off in the compartment 71 only. Thus, the valves 32 and 33 together with corresponding conduits, act as injectors whenever this is required.
Solvent vapors almost completely free of dust particles are withdrawn from the uppermost compartment 70 of the desolventizer DS through a vent conduit 90 and discharge into the condenser 91 while the flakes, after being desolventized (and dryed and toasted if the DS is designed for the combination of desolventizing, drying and toasting) in their passage through the various compartments in a direction opposite that of the live steam supplied via conduit 17, are discharged through conduit 93 for further processing.
The solvent vapors leaving the desolventizer are normally between 60 and 70 degrees C. and have little or no superheat. Superheat energy has largely been used in heating of the solids in chamber 70.
The desuperheated solvent vapors entering the condenser are condensed and withdrawn through conduit 92 for recycling or other utilization.
It will be observed that the process according to the invention requires no solvent cleaning equipment such as scrubbers, filters, or condensers between the pre-desolventizer and the desolventizer.
It will further be observed that the process according to the invention requires no such equipment down flow of the desolventizer DS with the exception of condensing means.
This is the result of employing indirect heating with the aid of steam in the pre-desolventizer where superheated solvent vapor is produced, employing direct heating with the aid of live steam countercurrent to the material to be treated in the desolventizer, and introducing the superheated solvent vapors coming from the pre-desolventizer directly into the desolventizer, preferably just below the upper section of the DS.
The superheated solvent vapors discharged from the pre-desolventizer PDS support the vaporization of solvent in the upper compartments of the desolventizer DS thus decreasing the total steam consumption as compared with a conventional plant by almost 5 to 15%.
It will be understood that the material to be processed as hereinabove specified can include all oil-bearing materials such as vegetable seeds, grains, nuts and like materials, cotton-seed, soya beans, tung nuts, linseed, castor beans, copra, bone meal, meat scraps and the like. The liquid adhering on the material to be treated can comprise inorganic and organic solvents such as water, aqueous solutions, gasoline, hexane, mixed paraffines, aromatic solvents, alcohols, ketones, aldehydes and other polar or nonpolar solvents.
Numerous characteristics and advantages of the invention for which this application has been submitted have been set forth in the foregoing description. It will be understood, however, that this disclosure is, in many respects, only illustrative. Changes may be made in details, particularly in matters of shape, size, arrangement of parts, and percentages of materials and fluids without exceeding the scope of the invention. The invention's scope is, of course, defined in the language in which the appended claims are expressed. | A continuous process for heat treating flowable materials having liquids thereon and apparatus wherein a first portion of adhering liquid is vaporized in a pre-desolventizer (PDS) consisting of at least one horizontal steam jacketed conveyor tube (60-63), the vaporized vapors of the liquid being directly discharged into a desolventizer (DS) consisting of a vertical chamber being divided into a certain number of compartments (70-73), live steam is introduced into the lowermost compartment (73) to vaporize the remaining portion of liquid adhering on the material and the combined vapors of liquid collected in the upper section of the desolventizer (DS) are discharged into a condenser (91) where a dust-free liquid is recovered. The desolventizer (DS) may also be used as a combined desolventizer-toaster-dryer. | 0 |
CONTRACTUAL ORIGIN OF THE INVENTION
The United States has rights in this invention pursuant to Contract No. DE-AC07-941D13223 between the U.S. Department of Energy and Lockheed Martin Idaho Technologies Company.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to radiotherapy planning for Boron Neutron Capture Therapy (BNCT). More specifically, the present invention relates to a method for improving the simulation and display of BNCT isodoses superimposed upon the anatomical features of a patient that are to receive BNCT treatment.
2. Background Art
Application of neutrons for radiotherapy of cancer has been a subject of considerable clinical and research interest since the discovery of the neutron by Chadwick in 1932. Fast neutron radiotherapy was first used by Robert Stone in the Lawrence Berkeley Laboratory in 1938. This technology has evolved over the years to the point where it is now a very viable method for treating inoperable salivary gland tumors. On the basis of recent research data such technology also is emerging as a promising alternative for treatment for prostate cancer, some lung tumors, and certain other malignancies as well.
Neutron capture therapy (NCT), a somewhat different form of neutron-based therapy, was proposed in the mid 1930s and, despite some notable failures in early U.S. trials, has attracted a great deal of renewed research interest lately. This interest is due to significant improvements in radiobiological knowledge.
The basic physical processes involved in fast neutron therapy and neutron capture therapy differ in several respects. In fast neutron therapy, neutrons having relatively high energy (approximately 30-50 MeV) are generated by a suitable neutron source and used directly for irradiation of the treatment volume, just as is done with standard photon (x-ray) therapy. In neutron capture therapy, a neutron capture agent is injected into the patient and is selectively taken into the malignant tissue. The administration of a pharmaceutical containing the neutron capture agent is preferably direct administration into the bloodstream of the patient. At an appropriate time after administration of the neutron capture agent, the treatment volume (i.e., the anatomical structure to be treated) is exposed to a field of thermal neutrons produced by application of an external neutron beam. Because boron-10 is commonly used as the capture agent, the technology has come to be known as boron neutron capture therapy, or BNCT.
The thermal neutrons interact with the boron-10, which has a very high capture cross-section in the thermal energy range. Ideally, the boron-10 is present only in the malignant cells so that boron-neutron interactions will occur only in malignant cells. Each boron-neutron interaction produces an alpha particle and a lithium ion. These highly-energetic charged particles deposit their energy within a geometric volume that is comparable to the size of the malignant cell. Thus, boron-neutron interaction provides a high probability of cell inactivation by direct DNA damage.
Because boron is ideally taken up only in the malignant cells, the NCT process offers the possibility of highly selective destruction of malignant tissue while causing minimal damage to the normal tissue disposed adjacent to the tumor. When boron-10 is taken up in the malignant cells only, the separation between normal and malignant tissue occurs on a cellular-level basis--thereby providing considerable accuracy. In addition, the neutron sources used for NCT are, themselves, designed to produce a minimal level of damage to normal tissue which has not received the neutron capture agent.
When BNCT is administered as a primary therapy, an epithermal-neutron beam (neutrons having energies in the range of 1 eV to 10 keV) is used to produce the required thermal neutron flux at depth. This is because these somewhat higher-energy neutrons will penetrate deeper into the irradiation volume before thermalizing. Although the neutrons penetrate deeper, they are still not of sufficient energy to inflict unacceptable damage to intervening normal tissue.
A third form of neutron therapy is also a subject of current research interest. The third form of neutron therapy is basically a hybrid that combines the features of fast neutron therapy and NCT. In this type of radiotherapy, a neutron capture agent is introduced into a patient--preferably into the malignant tissue only. This treatment is prior to the administration of standard fast neutron therapy. Because a small fraction of the neutrons in fast neutron therapy will be thermalized in the irradiation volume, it is possible to obtain a small incremental absorbed dose from the neutron capture interactions that result. Thus, based on current radiobiological research, improved tumor control appears to be likely when using the augmentation concept.
One significant problem with the various neutron therapy systems is that they are usually located only at major research centers because they are physically complex, bulky, expensive to acquire and require high-level operating staffs to maintain. In general these systems are not well suited for wide-spread, practical, clinical deployment.
This disadvantage is compounded by the fact that in BNCT and other neutron therapy systems detailed planning calculations are necessary to optimize the treatment for each individual patient. Careful planning permit the delivery of the highest possible therapeutic radiation dose to the target tissue while maintaining the surrounding healthy tissue at or below tolerance. However, extensive planning can limit the number of patients which can be properly treated using neutron therapy equipment. Thus, in recent years significant efforts have been made to develop modern computational methods and software for use in BNCT treatment planning.
One such treatment planning system for BNCT has been developed by the New England Medical Center Hospitals. This system is described in U.S. Pat. No. 5,341,292 (Zamenhof), entitled Monte Carlo Based Treatment Planning for Neutron Capture Therapy. The Zamenhof system displays a patient image superimposed with isodose contour lines. To obtain a patient image superimposed with isodose contour lines, the system must process both a physical distribution and a biological distribution. Processing both the physical and biological distributions each time a user desires to view isodose contours on a patient image is inefficient and time consuming.
In addition, the Zamenhof system uses an undesirable method to eliminate unwanted isodose contours. Isodose contours appear everywhere that they are computed to appear--even in areas of the display that do not have a patient image. The isodose contours that appear outside the patient image are undesirable. To get rid of these contour lines, the Zamenhof method sets computed isodose values outside the patient image to zero. Zamenhof, Col. 2, lines 2-4. Setting the computed isodose values to zero in the air regions outside the patient image causes the isodose curves to have unrealistic dropouts near the margins of the patient image. These dropouts are sharp and cause a general distortion throughout the isodose curves.
Other treatment planning systems consider the isodose contours to consist of one component and present the contours on top of a medical image or graphical, visual representation of anatomical features. Although these systems increase the speed of treatment planning, they are not as accurate as desired.
Thus, there is a need for a method for treatment planning that provides for isodose contour line displays superimposed over a patient image, while eliminating the contour lines in areas not of concern to the user. Such a system should be easy to use and enable more efficient treatment planning.
OBJECTS AND SUMMARY OF THE INVENTION
It is an object of the present invention to provide a system for displaying an accurate model of isodoses used in BNCT and related types of radiotherapy.
It is another object of the present invention to provide such a system which enables a graphic display of an image of a desired anatomical feature of a patient with isodose contours superimposed thereon to reflect radiotherapy treatment.
It is yet another object of the present invention to enable the user to select what portion of the anatomical feature and the surrounding area is displayed.
The present invention involves a method and a system, wherein the method involves processing signals to generate a visual display of a desired anatomical feature. Isodose contour lines representative of the radiotherapy are superimposed over the anatomical feature displayed so as to indicate the effect of the neutron therapy on the patient. A raster image is then superimposed on the anatomical feature of the patient and isodose contour lines to selectively mask the contour lines in areas other than the desired anatomical feature so that isodose contour lines that are not wanted will not appear. What determines which isodose contour lines are undesired and will not appear can be controlled by the user to thereby facilitate planing of the radiotherapy.
In accordance with another aspect of the present invention, the system includes a processor, typically a computer, connected to a display. The processor is programmed to process information supplied by the user to develop a graphical representation of the anatomical feature undergoing treatment, to develop a visual representation of the neutron propagation (contour lines) and to develop a raster image which selectively masks the undesired contour lines.
The present invention provides a convenient way for the user to remove the isodose curves from areas of the display that isodose curves are not wanted. Removing these isodose curves facilitates the envisioning of the computed dose information. The quicker comprehension of dose information gives this invention numerous advantages. Primarily, the invention will reduce the amount of clinical staff time spent developing a specific treatment plan. This, in turn, will increase patient throughput. An increased patient throughput allows for more efficient usage of expensive resources and thereby makes radiotherapy more cost efficient than in the past. Other advantages will become apparent from the detailed description and the claims.
In accordance with one aspect of the invention, the steps of providing a visual representation of the anatomical feature, superimposing an isodose pattern of contour lines generated by processing of the weighting values and applying a raster image to selectively mask contour lines outside a desired area is repeated until a desired contour line pattern is viewed on the display. With the desired contour line pattern present on the screen, the operator may then quickly determine the proper radiotherapy dose.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, features and advantages of the invention will become apparent from a consideration of the following detailed description presented in connection with the accompanying drawings in which:
FIG. 1 is an example of a view of a patient image superimposed with completely unmasked isodose contour lines to demonstrate the lack of clarity of images used in radiotherapy treatment planning;
FIG. 2 is a view of the contour masking tool showing a raster image of a model of anatomical features and selections for a user to control the application of the raster image;
FIG. 3 is an example of a patient treatment volume with isodose contour lines superimposed over the patient treatment volume and the extraphysical isodose contour lines being masked out by the raster image; and
FIG. 4 is a perspective view of a processor and a display device forming a graphical user interface.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference will now be made to the drawings in which the various elements of the present invention will be given numeral designations and in which the invention will be discussed so as to enable one skilled in the art to make and use the invention. It is to be understood that the following description is only exemplary of the principles of the present invention, and should not be viewed as narrowing the pending claims.
The method for displaying an accurate model of isodose contour lines from Boron Neutron Capture Therapy (BNCT) or other radiotherapy includes a number of steps. Following these steps is necessary to provide accurate and efficient planning of the radiotherapy. The method of the present invention is useful because if the steps are followed properly, the adverse affects of BNCT radiotherapy on a patient's normal tissue can be minimized, while at the same time improving planning time and patient throughput.
The first step of the method is obtaining a plurality of weighting values (or conversion factors) for at least one component of BNCT radiotherapy, etc. As stated above, BNCT radiotherapy usually involves a number of components which must be processed to provide an effective radiotherapy treatment plan. Each component has a weighting factor that affects the radiotherapy treatment of the total combination of components. The weighting values can be individually altered to change the radiotherapy treatment that is to be applied. To begin BNCT treatment planning, each BNCT component has weighting values assigned. The process for assigning the weighting values will be known to those skilled in the art of BNCT radiotherapy.
Weighting values, or conversion factors are empirical values determined through experimentation. Those skilled in the art are not in complete agreement on the entire group of weighting values. Thus, it is important to have a simulation method which enables rapid, accurate reproductions of the dose distributions. For this reason, it is helpful to have a table of weighting values and a selection tool to avoid tedious, error prone manual entry from a keyboard or other input device.
Once a particular weighting value is selected from a table or some other source, it is entered into a processor, typically by a means such as a keyboard. For this reason, a table of different weighting values is helpful. If the person entering the values is skilled in the art, common results of treatment with the given weighting values is also obtained.
Another way to assign weighting values is through a radiation transport module. Radiation transport modules are common and, in light of the present disclosure, those skilled in the art will recognize how to input the information obtainable therefrom to achieve the desirable results provided by the present invention. Most typically, the radiation transport module will have an output that is coupled to a computer. The computer processes the weighting values and other factors and generates signals which produce a visual representation on a display.
As a first step, the processor generates signals which are converted by the display into a graphical representation of an anatomical feature to be treated with the radiotherapy. Due to problems associated with operating on many tumors in the head, a cross-sectional view of a skull is a common image.
The next step in the method is computing at least one radiotherapy dose from the plurality of weighting values. The BNCT or other radiotherapy dose is computed based on the entire treatment volume. The treatment volume includes three areas: (a) the area of patient anatomy that is to receive radiotherapy, (b) the area including beam geometries, and (c) the area that includes air spaces in between the patient anatomy and the beam geometries. Thus, for example, the BNCT doses are computed for BNCT treatment planning regardless of the extra space involved in the treatment volume.
Once a dose is computed, isodoses can be derived by using currently available software on a conventional computer or other processor. The isodose is the actual dose that is used to administer the radiotherapy. The isodose is not easily visualized, so the next step is directed toward a method for viewing the isodose.
Viewing the isodose is accomplished by displaying contour lines to represent the derived isodoses. The contour lines extend through the entire treatment volume--i.e. the treatment volume and the surrounding environment. FIG. 1 shows a display screen 8 having an anatomical feature 12 displayed thereon. Preferably, the display screen 8 will serve as a graphical user interface and provide a tool bar 16 or other mechanism for selecting the information shown.
The anatomical feature 12 has contour lines 20 representing isodoses superimposed on the anatomical feature. As is apparent from FIG. 1, the isodose model shows contour line portions 24 which are superimposed on the anatomical feature 12, as well as contour line portions 26 that extend beyond the area of patient anatomy (hereinafter referred to as "extraphysical") and across air spaces in between the patient anatomy and the beam geometry. The contour line portions 24 are accurate as far as the patient anatomy is concerned, but with regard to the air spaces and beam geometries, the contour line portions 26 are inaccurate.
As was mentioned in the background section, methods have been developed to eliminate the extraphysical contour line portions 26. However, these methods often unnecessarily skewed the contour line portions 24 superimposed on the anatomical feature 12. Thus, as discussed above, there is a need to effectively eliminate the isodose contour line portions 26 that are inaccurately portrayed in the figure.
This step is accomplished by providing a user with a raster image, generally indicated at 44, which is shown in FIG. 2 on the display screen 8 and shown in FIG. 2. Because the display screen 8 will typically form part of a graphical user interface, a menu of options 48 or some other input arrangement will typically be provided.
The raster image 44 is configured for selectively mask out areas of unwanted isodose contour lines or line portions, such as the extraphysical contour line portions 26 of FIG. 1. The raster image 44 is an image that highlights a particular portion of the display. The highlighted portion of the display is the only portion of the display that is visible to a viewer. Thus, those areas of the display that are highlighted by the raster image will be the only areas of the display that are illuminated in the completed model of isodoses for use in BNCT or other radiotherapy and only contour line portions disposed within the highlighted area will be visible.
The final step of the method is to superimpose the raster image 44 on the anatomical feature 12 and the contour lines 20 to selectively mask out the areas of unwanted isodose contour lines or line portions. In this way, the model will display a patient image superimposed with realistic isodose contour lines or line portions as is shown in FIG. 3. The isodose contour line portions 24 do not extend beyond the image of the anatomical feature 12 and into the air spaces about the anatomical feature. Additionally, no processing has occurred with respect to the contour line portions 24 which would cause the contour lines 24 on the anatomical feature 12 to be skewed or otherwise inaccurate. Thus, an accurate model of isodoses in the radiotherapy appears on the display. This allows BNCT treatment planning to be accomplished with greater quality.
To accomplish the advantages of the present invention, little additional hardware is required. All of the calculations, processing and human perceptible display can occur on a conventional computer. Currently available programs permit the generation of the graphical image of the anatomical feature 12 and the contour lines 20 of the radiotherapy isodoses by the use of the weighting values discussed above. In light of the present disclosure, those skilled in the art will be able to find or prepare software designed to generate a raster image. By combining the respective elements, the significant advantages of the present invention can be achieved.
The software or firmware on the general purpose computer or other processor takes the computed dose and uses it to derive isodoses. In other words, the software processes the weighting values to derive the isodoses from the computed dose. The software on the processor then processes the derived isodoses and displays the isodose contour lines in a manner based on the derived isodoses.
The software on the processor is programmed such that it provides a user with a raster image to selectively mask out areas of unwanted isodose contour lines. While the raster image typically corresponds to the patient image on the display, the raster image could be modified to consider only portions of the anatomical feature depicted on the display. Thus, the patient image shows the anatomical features of a patient that are to be treated and an accurate representation of the contour lines.
The present invention can also be viewed as a system for displaying an accurate model of isodoses used in Boron Neutron Capture Therapy (BNCT) and other radiotherapy planning. BNCT radiotherapy uses a complex arrangement of dose components. Each dose component has a specific weighting value. The present invention assists a BNCT administrator in viewing the predicted treatment outcome of the various combinations of dose components and weighting values. The end goal of this method is to find weighting values of BNCT treatment that will have the greatest effect on the malignant tissue, while having the least detrimental effect on the normal tissue of the patient being treated.
As shown in FIG. 4, the system for displaying an accurate model of isodoses used in BNCT treatment uses a processor 50 in the form of a conventional computer. The processor receives input from a keyboard 52, or some other mechanism for imputing data regarding the weighting values or other variable to be applied.
The processor utilizes the information provided regarding the anatomical feature to be treated, the isodose to be applied, and the desired area of viewing to generate signals which are conveyed to a display device, such as a monitor 54. The display device converts the signals from the processor into a graphical representation of the anatomical feature, a contour line pattern superimposed on the anatomical feature indicative of the isodoses, and a raster image which may be superimposed on the anatomical feature and the contour lines to provide an image of the contour lines superimposed only a desired portion of the anatomical feature and not over the extraphysical area.
By layering the graphical representations of the anatomical feature (FIG. 1), the superimposed contour lines (FIG. 1) and the raster image (FIG. 2), the view provided to the user is that of the anatomical feature 12, or desired portion thereof, and only the relevant contour lines. Because no attempts have been made to change the parameters to remove the extraphysical contour line portions and the isodose image (FIG. 1) is computed for the entire treatment volume, the portions of the contour lines superimposed on the anatomical feature are accurate. Thus, by masking, accuracy may be maintained while still providing a convenient visualization tool.
The above variations are not inclusive. They are only examples of the preferred embodiments. It is to be understood that the above-described arrangements are only illustrative of the application of the principles of the present invention. Numerous modifications and alternative arrangements may be devised by those skilled in the art without departing from the spirit and scope of the present invention. The appended claims are intended to cover such modifications and arrangements. | A system for displaying an accurate model of isodoses to be used in radiotherapy so that appropriate planning can be performed prior to actual treatment on a patient. The nature of the simulation of the radiotherapy planning for BNCT and Fast Neutron Therapy, etc., requires that the doses be computed in the entire volume. The "entire volume" includes the patient and beam geometries as well as the air spaces in between. Isodoses derived from the computed doses will therefore extend into the air regions between the patient and beam geometries and thus depict the unrealistic possibility that radiation deposition occurs in regions containing no physical media. This problem is solved by computing the doses for the entire geometry and then masking the physical and air regions along with the isodose contours superimposed over the patient image at the corresponding plane. The user is thus able to mask out (remove) the contour lines from the unwanted areas of the image by selecting the appropriate contour masking region from the raster image. | 0 |
BACKGROUND OF THE INVENTION
The present invention relates to a method of, and an apparatus suitable for use in, packing slaughtered birds, including poultry, into an envelope, especially a bag or a bag shaped package, to be sealed after filling.
In a method which has been proposed for the mechanical packing of poultry to be frozen, the legs of the poultry are folded against the bird after which the whole bird is pressed into a package and the package is sealed behind the legs. An apparatus for carrying out this method has been proposed and is based on the same principle; that is: first the legs are folded or bent up and then the body is pushed into the package.
It will be appreciated that, when packing birds, for example poultry, in a folded configuration, spare room must be allowed so that the birds can be inserted in the bags with the bags reliably not being split. This is, of course, disadvantageous when the birds are to be frozen, it being well-known that as small a bag as possible should be used for freezing, so that the likelihood of ice-burning can be reduced.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a method and apparatus which can be used to help alleviate the aforementioned difficulties.
According to a first aspect of the present invention there is provided a method of mechanically packing a slaughtered bird, including poultry, which method comprises inserting a bird having extended legs into an envelope, thereafter folding the legs and sealing the envelope.
In accordance with a preferred embodiment of the first aspect there is provided a method of mechanically packing a slaughtered bird, including poultry which method comprises opening an inlet of an envelope, such as a bag, resting on a support, pushing a bird resting with stretched legs on a support into the envelope by exercising a force on the body of the bird, then pressing the legs upwardly to locate the legs in a folded position on both sides of the body and thereafter sealing the envelope.
According to a second aspect of the present invention there is provided an apparatus suitable for use in packing a slaughtered bird, including poultry, which apparatus comprises means for retaining an inlet of an envelope in an open position, means for inserting a bird into the envelope through the inlet, means for folding the legs of the bird when the bird is in the envelope and means for sealing the envelope.
In accordance with a preferred embodiment of the second aspect there is provided an apparatus suitable for use in packing a slaughtered bird, including poultry, which apparatus comprises means for acting upon the inner surface of an inlet of an envelope, such as a bag, for keeping the inlet of the envelope open, means for supporting the envelope and the bird, first reciprocable pusher means movable in a direction toward and into the envelope through the inlet for pushing the bird into the envelope through the inlet, second reciprocable pusher means movable in a forward direction toward and into the envelope through an inlet for acting on the legs of the bird when positioned in the envelope to fold the legs of the bird, drive means for the first and second pusher means, the drive means being such that first the first pusher means and then the second pusher means can act in use on the bird whilst moving in the forward direction, toward the inlet and means for sealing the envelope, having the birds positioned, in use, therein.
The present invention enables the provisions of an apparatus and method in which a bird, such as poultry, within ample limits independent of its dimensions, can be packed in such a manner that a compact whole is obtained in which the envelope, such as a bag or package encloses the bird narrowly that is the bird can be closely encased in the envelope.
In a preferred embodiment of a method in accordance with the present invention, the inlet of a bag resting on a support is opened and the bird resting with its back on an adjoining support, is pushed into the bag with extended legs, the legs are thereafter pressed up till they are in a folded position on both sides of the body, and subsequently the bag is sealed behind the legs.
Advantageously, a bow-shaped member extends across the bird at the upper part of the legs thereof partly to encircle the bird whilst the bird is inserted into the envelope. The legs of the bird are preferably retained in the folded or pushed up position before the envelope is sealed.
A method in accordance with the present invention can be very easily carried out mechanically, can result in a very compactly packed bird, the envelope encasing the body very narrowly.
One embodiment of an apparatus in accordance with the present invention comprises elements acting upon the inner surface of an inlet of a bag for keeping open the inlet; elements movable through them for pushing the bird into the bag, a support for both the bag and the bird, a first pushing element movable in the direction of the opening of the bag and backward for pushing up the body of the bird, a second pushing element also movable in the direction of the opening of the bag and backward for working on the ends of the legs, drive means for the first and second pushing elements respectively, the drive means being such that, in use, first the first pushing element and then the second pushing element is pressed in a direction toward the opening of the bag and elements for sealing the bag behind the legs.
Advantageously, the apparatus comprises a bow-shaped member for extending across the bird at the upper part of the legs thereof partly to encircle the bird whilst the bird is pushed, in use, into the envelope.
A preferred embodiment of an apparatus in accordance with the present invention can have a number of main operating elements, the movement of which is rectilinear and the various movement of which can be derived from each other. Such a preferred apparatus can be of simple construction and may reach a very high rate of production. Advantageously, correct positioning of the bird in the envelope is facilitated by positioning the bird by means of the bow-shaped member which partly encircles or encloses in use, the bird with respect to the envelope and then pushing the legs upwards by means of a bow-shaped pushing means.
Preferably the first pusher means is coupled with a pair of tongs having jaws movable with respect to each other. This first pusher means may comprise or be formed by, a pressing edge extending, in use, over the tail of the bird.
The coupling or combination of the first pusher means with the pair of tongs has the advantage of facilitating operational placing of the bird in the apparatus, that is placing of the bird between the jaws. The pressing edge is a suitable element for exercising force on the bird in a longitudinal direction.
A preferred embodiment of an apparatus in accordance with the present invention comprises means attached to a bearer or carrier for retaining the legs in the folded or pushed up position. Advantageously the means comprises a flexible element. This element preferably fixes or retains in use, the legs and spans the envelope rigidly over the legs while the envelope is being sealed.
The means for acting upon the inner surface of the inlet advantageously comprises members through which the first pusher means can move, the members consisting of two, preferably oblong, longitudinal funnel portions positioned opposite each other and movable in a longitudinal direction, ends of the portions directed toward the inlet of the open envelope being guided, in use, such that the ends, whilst moving, in use, from a starting position, toward the envelope, can also move away from each other to a final position in which the ends extend, in use, into the envelope and clasp the envelope against stops. Advantageously, the bow-shaped member extends, in use, into the envelope and is attached to a pivot arm. The drive for the pivot arm is preferably synchronised with that of the funnel portions such that, in use, forward movement of the funnel portions causes upward movement of the pivot arm, and inversely, that is backward movement of the funnel portions causes downward movement of the pivot arm.
Advantageously, the means for supporting the bird and envelope during packing comprises three, aligned corresponding portions, the portions being a first support, such as a first supporting table located below the pair of tongs and the first pusher means, a second support, such as a second supporting table, preferably comprising a horizontal portion and a downwardly directed portion, for supporting a stack of the envelope and a third discharge support, such as a third discharge table, which can be pivoted away from the second support. Advantageously, the height of the second support is adjustable such that the upper face of the stack of envelopes situated, in use, on the second support can adjoin the supporting surface of the first support.
The bearer for the flexible element is preferably fastened to the third discharge support.
SURVEY OF THE DRAWINGS
FIGS. 1, 2 and 3, each show schematically a side view of an embodiment of an apparatus in accordance with the present invention in sequential stages of inserting a bird in a bag, one of the funnel portions being omitted, for reasons of clarity, from FIGS. 2 and 3,
FIG. 4 shows an enlarged bottom view of the bearer and tongs member of the embodiment apparatus of FIG. 1,
FIG. 5 shows a part-sectional side view on an enlarged scale of the carriage part of the apparatus, the various members of the part being in the same relative positions as shown in FIG. 1, and
FIGS. 6, 7 and 8 each show in detail and on an enlarged scale a side view of the bag supporting part of the embodiment apparatus in sequential stages of sealing a bag having the bird positioned therein and ejection of the sealed bag from the apparatus.
DESCRIPTION OF PREFERRED EMBODIMENTS
Various parts of the apparatus shown in the Figures are illustrated schematically only and drive means for the various parts which is preferably pneumatic but may be hydraulic or electric, will not be explicitly described.
Referring to the drawings, the embodiment apparatus comprises three longitudinally aligned supports namely a first support table 1 having a reciprocably movable sledge or carriage 2 driven by a pneumatic cylinder 2a, a corresponding second support 3 for supporting the bags in which the poultry is to be packed, and a corresponding pivotal discharge table 4 which can pivot or tip to the left as shown in the drawings.
The table 1 also supports two longitudinal upright preferably oblong, portions or plates 5, (one of which is clearly visible in FIG. 1) positioned opposite each other and to form therebetween a funnel for keeping open the inlet end of a bag 6. The funnel plates 5 are guided and driven such that, as the funnel plates 5 move forward the foremost edges or front ends of the funnel plates diverge to keep the bag 6 open.
In a preferred embodiment, the funnel plates 5 are movable in a longitudinal direction by drive means which cause the plates 5 to move from a starting position toward the bag. During this movement, the ends of the plates 5 directed toward the inlet end of the open bag are guided in such a way that they diverge, that is move away from each other, to a final position wherein the ends extend into the bag and clasp the bag against stops.
A bow 7 connected to a pivot arm 7a and coupled to the drive means for the funnel plates 5 performs the double function of keeping the bag 6 open and of guiding the breast side, that is the breast and legs of the poultry.
In a preferred embodiment, the bow 7 is coupled to drive means for the funnel plates 5 such that forward movement of the plates 5 causes the bow 7 to extend into the open end of the bag 6 and the pivot arm 7a to move upwardly. Avantageously, backward movement of the plates 5, that is movement away from the closed end of bag 6, causes the bow 7 to leave the bag and the pivot arm 7a to move downwardly.
Although the supports are shown in FIGS. 1 to 3 to the horizontal, in actual practice the supports are inclined to the horizontal as shown in FIGS. 6 to 8.
The carriage 2 is provided with a bearer or support member 10 to which arms 8a and 8b of a tongs member are attached. The support member 10 has, at the foreside, that is the free end, thereof, a pressure or pressing edge 22 the purpose of which will be explained hereinafter. The arms 8a and 8b of the tongs member have inwardly bent end portions 12a and 12b pivotally mounted to the support member 10 via fixed pivots 11a and 11b, respectively. The inner ends of bent end portions 12a and 12b have open slot holes 13a and 13b in which driving pins 14a and 14b fastened to a sliding member or piece 15 can engage. The sliding member 15 is carried by a rod 16 arranged in fixed bearings 17 and 18 connected to the support member 10. A fixed stop 21 is provided to contact an end 20 of the rod 16, when the rod 16 is in its furthermost position from the support 3. A spring 19 is arranged on the rod 16 and biased to press the rod 16 to the right so as to cause the arms 8a and 8b to move from the open or spread position shown in discontinuous lines in FIG. 4 to the closed position shown in continuous lines. Movement to the right of the support member 10 causes the end 20 of the rod 16 to contact the stop 21 (as shown in continuous lines in FIG. 4). Further movement to the right causes the arms 8a and 8b to open or spread (as shown in discontinuous lines in FIG. 4) and the spring to be compressed against its bias. Further movement to the left, that is toward the second support 3, causes the arms 8a and 8b to close aided by the bias of the spring 19.
The carriage 2 also bears at least one, preferably two, bowl-shaped pushing element 9. The drive for the tongs member and for the pushing element 9 is such that movement of the carriage 2 to the left causes first the arms 8a and 8b to move to the left and, after traversing a certain distance, the pushing element 9, originally positioned behind the arms 8a and 8b, overtakes the arms as shown in FIG. 3.
The discharge table 4 is located partly on the second support 3 so as to lie under the closed end portion of the bags 6. The discharge table 4 is connected to a support or arm 29 having at the free end thereof a fixed pivot point 30. Bow members or arms 25 are pivotally mounted on the discharge table 4 by means of fixed pivots 26.
The free ends of the bow members 25 are interconnected by a flexible element 27 such as string arranged transversely of the bow members 25 (as shown in FIG. 6). The bow members 25 can be pivoted downwardly by suitable drive means.
The operation of the apparatus will now be described.
The carriage 2 is, in the starting position thereof, located in its farthermost position from the second support 3, that is in its most right-hand position. As a result, due to the cooperation of the end 20 with the stop 21, the arms 8a, 8b of the tongs member are open, that is spread, as shown in discontinuous lines in FIG. 4. A bird 23 to be packed is manually placed between the arm 8a, 8b, the tail being arranged under the pressure edge 22 of the support member 10. Subsequently, the drive for the sledge 2, that is the cylinder 2a, is put into operation either manually or by means of a control which reacts to the placing of the bird, for example a photoelectric control, and as a result the carriage 2 commences its movement to the left. The arms 8a, 8b move toward each other as previously explained and enclose the poultry resiliently as shown in FIG. 1. The poultry, guided by the funnel plates 5 and the bow 7, is then pressed into the bag 6. FIG. 2 shows the bird 23 on arrival at the front part of the bag being guided on top by the bow 7, and on the sides by the funnel plates 5 and being pushed forward by the arms 8a, 8b and the pressure edge 22. The pushing element 9, however, is at the point about to rapidly overtake the arms 8a, 8b and the pressure edge 22, and, shortly after the situation shown in FIG. 2, that is while the bird is still located below the bow 7, the pushing element 9 overtakes the end of legs 24 of the bird 23. The legs are thereby pushed up and located in bent position along the body by the pushing element 9 shown in FIG. 3.
In order to seal the bag 6, both the arms 8a, 8b and the pushing element 9 should be moved back that is to the right, in order to be able to seal the bag directly behind the legs. When the bird is in the position shown in FIG. 3 the bow members 25 are pivoted downwardly to the position shown in FIG. 6 and, as a result, the string 27 encircling partly or enclosing the bag 6 is spanned around the legs of the bird and keeps the bird in position.
The various stages of sealing the bag and of discharging the bird from the apparatus are explained with reference to FIGS. 6 to 8.
A sealing mechanism 28 which may be any suitable known sealing mechanism, for example those utilising self-adhesive tape or fusion of a bag-shaped package, is illustrated in full in FIG. 6. Such a sealing mechanism is known per se and, therefore will not be discussed in further detail. FIG. 6 shows the situation in which the bag is sealed directly behind the end of the legs 24 of the bird still partly encircled by the flexible element 27, the bird resting on the discharge table 4. Under the action of various driving mechanisms shown in the drawings but not described in detail, and after the sealing of the bag by the sealing mechanism 28, the bow 25 is pivoted upwardly while the discharge table 4 begins to pivot or tip to the left about the fixed point 30 as indicated by the arrow 31 in FIG. 7. Finally, the situation shown in FIG. 8 is reached, that is the bird 23 falls from the discharge table 4 into a container (not shown) placed thereunder.
Of course, a packing apparatus constructed according to the bow-shaped can have a number of preferred provisions which, will not be discussed explicitly because they are not essential to the present invention. For example a nozzle 32, shown in FIGS. 6 to 8 can be provided for sucking off that part of the bag remaining after sealing. As shown in FIG. 6, this nozzle is closed by the bow 7 during sealing. When the discharge table 4 tips away the bow 7 is tipped sideways, or moved backwardly by a suitable command mechanism to release the nozzle. Furthermore, the support 3 for the bags can be provided with a suitable mechanism for always positioning the uppermost bag on the right level with respect to the funnel plates 5 and the funnel plates can be coupled with a suitable mechanism for displacing them forward and sideways in order to enclose a new bag blown open by means of a blower. | A method of mechanically packing a slaughtered bird, including poultry, comprising opening an inlet of an envelope resting on a support, pushing a bird resting with stretched legs on a support into the envelope by exercising a force on the body of the bird, then pressing the legs upwardly to locate the legs in a folded position on both sides of the body and thereafter sealing the envelope. | 1 |
FIELD OF THE INVENTION
[0001] The present invention relates to a method for treating colonic viscerosensitivity and spasticity. In particular, the invention relates to the use of therapeutic agents for the treatment of certain colonic reactions, which are induced by the procedure of colonic endoscopy, of barium/air contrast colonic radiography and/or virtual colonoscopy. Such reactions can be, for example, specific typical bowel reactions induced by the said procedures such as the painful viscerosensitivity and spasticity induced by aeric, gaseous or liquid distension.
BACKGROUND OF THE INVENTION
[0002] Barium/air contrast colonic radiography (Computerised Tomography (CT) colonography) and virtual colonoscopy are radiographic techniques aiming at imaging the colon for anatomical appearance, endoluminal lesions or mucosal abnormalities. In both procedures, a small, flexible tube is passed few inches into the rectum, and a small balloon is inflated to allow air to be gently pumped into the colon using a hand-held squeeze bulb. Sometimes, an electronic pump is used to deliver carbon dioxide gas into the colon. The purpose of the gas is to distend the colon to eliminate any folds or wrinkles that might obscure polyps or other lesions from the physician's view. In the case of colonic radiography, barium (a radio-opaque heavy metal) is also pumped in the rectum, and this barium covers the inner-lining of the colon creating a contrast with the intra-abdominal organs. Mucosal and endo-luminal abnormalities can be depicted and diagnostically interpreted by radiologists.
[0003] In the case of Virtual colonoscopy, CT colonography uses CT scanning to obtain an interior view of the colon (the large intestine) that is ordinarily only seen with an endoscope inserted into the rectum. CT imaging uses special x-ray equipment to produce multiple images or pictures of the inside of the body and a computer to join them together in cross-sectional views of the area being studied. The images can then be examined on a computer monitor or printed.
[0004] Colonoscopy is a test that allows physicians to look at the interior lining of the large intestine (rectum and colon) through a thin, flexible viewing instrument called a colonoscope. A colonoscopy helps detect ulcers, erosions, polyps, tumors, and areas of inflammation or bleeding. During a colonoscopy, tissue samples can be collected (biopsies) and abnormal growths can be removed. Colonoscopy can also be sued as a screening test to identify and remove precancerous and cancerous growths in the colon or rectum.
[0005] Before this test, the colon needs to be cleaned out. Colon prep takes 1 to 2 days depending on the preferred prep selected.
[0006] Endoscopical or virtual Colonoscopy is usually a painful procedure. Air distension of the colon wall, stretching of the mesenteric attachment and colonic spastic contractions are usually the causative factors for the pain experienced by the patients. A better tolerability of nociceptive air distension of the colonic wall, and the fewer spastic contractions allow for a reduced time to reach the coecum and successfully complete the colonic examination, for a better patient's tolerance of the procedure, and for a better acceptance of repeated procedures.
[0007] No specific guidelines exist to regulate the use of analgesic modalities in the performance of virtual colonoscopy, barium/air contrast colonography or endoscopical colonoscopy.
[0008] For endoscopical colonoscopy, it is therefore not surprising to find an impressive list of proposed analgesia and/or sedation modalities that are used in different countries and in different investigation units i.e. hospital-based or out-patient clinic facilities. This list encompasses general anesthesia performed by anesthesiologists, sedo-analgesia performed by anesthesiologists or gastroenterologists, sedo-analgesia performed by a trained nurse. Sedo-analgesia is the most frequently used type of sedation during colonoscopy worldwide. It is usually achieved by combining midazolam with propofol and/or fentanyl or pethidine.
[0009] When these proposed pharmacological modalities are administered, a constant per- and post-procedure patient monitoring is required to avoid risks of cardio-vascular or respiratory complications, thereby generating increased costs in time, specialized personnel and specialized space allocation. These drawbacks led to the evaluation of the risks and benefits of performing endoscopical colonoscopy with or without sedation. (J Clin Gastroenterology 1998, June: 24(4):279-282). In summary it is now well accepted that it is feasible and safe to perform a successful colonoscopy without sedation, and this usually does not undermine the willingness of patients to undergo a similar procedure in the future.
[0010] It would therefore be highly desirable to be provided with a method that would be an alternative to the previously proposed methods. It would therefore be also highly desirable to be provided with a method that would permit to overcome at least some of the prior art drawbacks.
SUMMARY OF THE INVENTION
[0011] In accordance with one aspect of the present invention, there is provided a method of treating colonic viscerosensitivity and spasticity induced by a colonic examination chosen from colonic endoscopy and of barium/air contrast colonic radiography and virtual colonoscopy. The method comprises prescribing and/or administering to a patient in need thereof a pharmaceutically effective oral, sub-lingual, nasal or trans-dermic dose of a non-centrally-acting opioid agonist for a period of at least two days before the colonic examination.
[0012] In accordance with another aspect of the present invention there is provided a method of treating colonic viscerosensitivity and spasticity induced by a colonic examination chosen from colonic endoscopy, barium/air contrast colonic radiography and virtual colonoscopy. The method comprises prescribing and/or administering to a patient in need thereof a pharmaceutically effective intravenous infusion of a non-centrally-acting opioid agonist before carrying out the colonic examination.
[0013] In accordance with another aspect of the present invention there is provided a method for carrying out a colonic examination chosen from colonic endoscopy, barium/air contrast colonic radiography and a virtual colonoscopy on a patient comprising:
[0014] prescribing and/or administering to the patient a non-centrally-acting opioid agonist to be taken at least once a day for at least two days before carrying out the colonic examination so as to eliminate or reduce the risks of pain generated by colonic viscerosensitivity and spasticity induced during the colonic examination; and
[0015] introducing into the patient's rectum an endoscope, colonoscope or any instrument required for the colonic examination.
[0016] In accordance with another aspect of the present invention there is provided in a method of carrying out a colonic examination chosen from colonic endoscopy, barium/air contrast colonic radiography and a virtual colonoscopy on a patient, the improvement wherein a non-centrally-acting opioid agonist to be taken at least once a day for at least two days before carrying out the colonic examination is prescribed and/or administered to the patient so as to eliminate or reduce the risks of pain generated by colonic viscerosensitivity and spasticity induced during the colonic examination.
[0017] In accordance with another aspect of the present invention there is provided a method for eliminating or reducing the risks of pain generated by colonic viscerosensitivity and spasticity induced during a colonic examination. The method comprises administering a non-centrally-acting opioid agonist to be taken at least once a day for at least two days before the colonic examination.
[0018] In accordance with another aspect of the present invention there is provided the use of a non-centrally-acting opioid agonist for treating viscerosensitivity and spasticity induced during a colonic examination.
[0019] In accordance with another aspect of the present invention there is provided the use of a non-centrally-acting opioid agonist for eliminating or reducing the risks of pain generated by viscerosensitivity and spasticity induced during a colonic examination.
[0020] In accordance with another aspect of the present invention there is provided the use of a non-centrally-acting opioid agonist in the manufacture of a medicament for eliminating or reducing the risks of pain generated by viscerosensitivity and spasticity induced during a colonic examination.
[0021] In accordance with another aspect of the present invention there is provided the use of a non-centrally-acting opioid agonist in a preventive treatment for eliminating or reducing the risks of pain generated by viscerosensitivity and spasticity induced during a colonic examination.
[0022] For example, the non-centrally-acting opioid agonist can be chosen from Trimebutine maleate, Nor-desmethyl trimebutine, azimadolin, their salts, isomers or enantiomers, and mixtures thereof.
DETAILED DESCRIPTION OF THE INVENTION
[0023] The present invention will be more readily understood by referring to the following example, which represents in a non-limitative manner preferred embodiments.
Example 1
[0024] A 52 year old male financial analyst (HB) was referred for colonic polyps screening in the context of familial incidence of colonic cancer; his father had died of metastatic colonic cancer at the age of 62 years. The patient had received a complete colonoscopy three years before in a hospital-based gastrointestinal unit, and this experience left him very anxious concerning the need for a repeat examination. The occurrence of pain during the procedure as well as the discomfort lasting few hours following the colonoscopic examination, despite parenteral sedation/analgesia, was still vivid in his memories. He wanted to negotiate an alternate diagnostic procedure such as a air-contrast barium enema. Because full endoscopical examination of the colon is recognised superior to barium-enema colonography and even to “virtual colonoscopy”, he was proposed and finally accepted a new experimental pharmacological preparation consisting in the administration of Trimebutine maleate 200 mg tablets to be taken orally three times a day for three days before the scheduled examination. He was instructed to completed this pharmacological preparation by taking two Fleet® Phospho-soda 45 ml vials with five or six glasses of liquid one in the evening before the examination, and one in the morning two hours before the examination to clean—prep the colon. He presented alone to the out-patient endoscopy clinic and he was appropriately positioned on his left side on the examination table, and the video-endoscopic colonoscopy was initiated by the endoscopist. The colonoscopy was easily completed to the coecum in 14 minutes. No colonic spastic contractions occurred, and the air-distension of the colon needed for the progression of the instrument did not generate pain or discomfort to the patient. The whole colonic examination including the accurate examination of the colon upon retraction of the instrument lasted a total of 25 minutes and was negative for mucosal lesions nor for endoluminal polypoid formations. The patient then dressed up and walked to the endoscopist's office to receive the good results of the examination. He was asked several questions on his experience of the new pharmacological preparation as compared to his previous hospital-based unit experience with parenteral sedation/analgesia. He qualified the experience a very positive one; he said he did not experience any pain and very mild discomfort during the procedure. He admitted to be prepared to receive a repeat procedure with the same preparation in a similar set-up, and was happy drive home by himself without any assistance or recovery time. The endoscopist and the assistant nurse were very satisfied with the ease and shortness of the completed procedure.
Example 2
[0025] A 62 year old female retired nurse (LA) presented with lower, and occasionally generalised, abdominal cramping together with predominantly loose motions. As part of a complete investigation, a colonoscopy was planned. She was prescribed Trimebutine maleate 200 mg tablets to be taken orally three times a day for three days before the scheduled examination. She was instructed to completed the pharmacological preparation by taking two Fleet® Phospho-soda 45 ml vials with five or six glasses of liquid, one in the evening before the examination, and one in the morning two hours before the examination to clean—prep the colon. Although she presented to the out-patient endoscopy unit with doubts that she could sustain the planned examination without any other drug preparation, having seen in her career many patients undergoing and barely tolerating this procedure of full colonoscopy, even after having received meperidine and/midazolam intravenously before the examination. She also remembered the “stress” striking the endoscopist and the assistant nurse working at completing the examination rapidly and successfully reaching the coecum in these patients. Nonetheless, she consented at trying to receive the examination without further pharmacological preparation, with the promise by the physician that the procedure would be interrupted at her request in the case that she could not tolerate the pain or discomfort. After appropriately positioning the patient on her left side, the instrument was delicately introduced in her rectum, and the progression of the instrument gently initiated. She asked to have her head elevated with a pillow so she could see the video monitor and watch the video-endoscopic recording of her examination. The progression of the instrument in the patient was easy, painless and the coecum was reached in 12 minutes. No spastic contractions delayed the progression of the instrument, and only mild but perfectly tolerable discomfort was experienced by the patient during the examination. The physician and the nurse were surprised by the fact that such a patient presenting a clinical Irritable bowel syndrome could experience so little discomfort during the examination since these patients characteristically are chronically suffering from a very low threshold of viscerosentivity with solid or gaseous distension of the colon. After the procedure, she commented that she would accept to a repeat examination any time, and would not hesitate to recommend this pharmacological preparation to patients needing complete colonoscopy, and would be ready to reassure them that there were no more reasons to fear to receive such examination.
Clinical Trial
Patients and Method
[0026] A clinical study was then initiated in patients referred by general practitioners to an out-patient endoscopy unit mainly to receive a screening colonoscopy in cases with family history of adeno-carcinoma of the colon. All patients gave informed consent to take part in the trial, which was conducted in accordance with the Revised Declaration of Helsinki.
[0027] Exclusion criteria were:
i pregnancy or lactation; ii significant clinical or laboratory evidence of pulmonary, hepatic or renal disease or dysfunction; iii need for non-steroidal anti-inflammatory drugs, pain-killer drugs or antispasmodic agents.
[0031] The study was an open-label, single-institution, unblinded prospective pilot trial aimed at establishing whether a controlled double-blind trial is warranted.
Medication
[0032] Trimebutine maleate was used in the form of 200 mg tablets, given three times a day before meals for two or five days before the procedure and for one or two days after the examination
Symptom Assessment
[0033] The severity of symptoms experienced during the examination was assessed by the use of a visual analog scale filled in by the patients only a few minutes after the examination, and a telephone call by the assistant nurse was made two days after the procedure to inquire about any symptom or any event having occurred after the patient had resumed its normal activities. The analog scale consisted of a line marked by numbers at equal intervals from 0 to 10. Zero indicated absence of symptoms while 10 represented symptoms severe enough to interrupt the progression of the endoscopic instrument. Assessed symptoms included abdominal pain/discomfort, abdominal distension and flatulence. Symptom scores were tabulated and statistical were analysis carried out using Students t-test.
[0034] This study is in progress and aims at recruiting approximately 50 patients. The results of this study are so far quite encouraging and reflect the results obtained in the individual case studies.
[0035] While the invention has been described in connection with specific embodiments thereof, it will be understood that it is capable of further modifications and this application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains and as may be applied to the essential features hereinbefore set forth, and as follows in the scope of the appended claims. | There is provided a method of treating colonic viscerosensitivity and spasticity induced by a colonic examination chosen from colonic endoscopy and of barium/air contrast colonic radiography and virtual colonoscopy. The method comprises prescribing and/or administering to a patient in need thereof a pharmaceutically effective oral, sub-lingual, nasal or transdermic dose of a non-centrally-acting opioid agonist for a period of at least two days before the colonic examination. | 0 |
This is a divisional of co-pending application Ser. No. 102,145 filed on Sept. 22, 1987, now U.S. Pat. No. 4,894,040.
BACKGROUND OF THE INVENTION
The invention concerns a toy building set with elements for providing positional information by detection of radiated, reflected energy, such as light.
Associated toy elements are known in the form of a light source and a light detector, respectively, said light detector being adapted to detect the light transmitted from the light source. This prior art provides an information signal by insertion of light absorbing means in the path of the light beam.
The object of the invention is to provide a toy building set with improved means with respect to the prior art for providing positional information.
SUMMARY OF THE INVENTION
This object is achieved in that the toy building set comprises an element of the type defined in the characterizing portion of claim 1. Thus, the invention comprises the use of an integrated electric circuit known per se which both contains a source and a detector, preferably for light, and the special advantages of the invention are obtained by using a detector of this type in a housing which is partly connectible with other elements belonging to the building set and is partly adapted for coupling with various forms of energy reflecting means. Preferably, the circuit is of the type where the transmitted light intensity is automatically increased if the received light signal weakens, which entails that it is sufficient with two leads to the circuit as the circuit will draw a supply current which is dependent upon the light reflection conditions (see e.g. Electronic Design, March 1982, p. 255).
It is observed that the energy radiating source and energy receiving detector defined in claim 1 were stated as being a light source and a light receiver above, which is a preferred embodiment and does not prevent the use of something else than ordinary light, such as microwaves.
Claim 2 provides an example of an energy reflecting means for cooperation with the building element of claim 1. The disc may e.g. be a tachometer disc or the disc may be provided with wind cups and thus serve as an anemometer.
Another example of an energy reflecting means in the form of a light conductor which may be coupled mechanically with the building element, so that the region sensitive to detection may be moved away from the immediate vicinity of the building element.
Another expedient element for the building set of the invention is an element comprising a line code for cooperation with the light detecting element, either directly or indirectly via light conducting means.
The light source may be a laser thus making it possible to perform a highly sensitive detection. For example, the oscillations of a membrane can be registered by means of coherent light, and in particular in such a detection it is important that the structure is mechanically stable and geometrically well-defined. When coherent light is used, the variations in the reflective power of the energy reflecting means may be obtained.
The mentioned examples, which will be described more fully later, indicate various situations where special advantages are obtained by positioning both the light source and the light receiver in a housing having mechanical coupling means, which involve pre-determined positioning of both the transmitter and the receiver with respect to other energy reflecting building elements of the toy building set.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be explained more fully by the following description of some embodiments with reference to the drawing, in which:
FIG. 1 shows a known element from a toy building set,
FIGS. 2 and 3 schematically show the essential parts of an embodiment of the toy building set of the invention,
FIGS. 4-7 show various embodiments of energy reflecting means,
FIG. 8 schematically shows a use of the toy building set of the invention,
FIG. 9 schematically shows another use of the toy building set of the invention,
FIGS. 10-12 show in more detail an embodiment of the building set, seen from below, from the side and from the top, respectively, while
FIG. 13 is a section along the line XI--XI in FIG. 11.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a known building element comprising a hollow body 1 having on its upper side a plurality of coupling studs 2 and on its underside complementary coupling means for connection with the coupling studs on an adjacent element (cf. FIG. 10). The embodiments of the building element of the invention described below are adapted to cooperate with the building element in FIG. 1, but it will be appreciated that the building element of the invention may be arranged to cooperate with other known forms of interconnectible toy elements.
FIGS. 2 and 3 schemically show the main components of an embodiment of the building element of the invention. Thus, FIG. 2 shows a hollow box 3 having four coupling studs 2 on its upper side, two of the coupling studs from FIG. 1 being replaced by a pair of through holes 4 for reception of an electric plug. Further, the housing 3 has two holes, partly a large hole 5 and a small hole 6. FIG. 3 shows an insert generally designated by 7 and comprising a plate 8 whose base is formed with the complementary coupling means mentioned in connection with FIG. 1 (see also FIGS. 10 and 13). The plate 8 is contiguous partly with a bushing 9 and a holder 10 adapted to retain an electric circuit board 11, which, in addition to electronic circuits, comprises a combined light source and light detector 12 as well as two electric coupling bushings 13 for cooperation with the plug pins which can extend through the holes 4 in FIG. 2.
It will be appreciated that the insert 7 may be received in the housing 3 so that the through hole in the bushing 9 is flush with the hole 5 (and an aligned hole in the opposite side of the housing 3), and so that the light element 12 is flush with the hole 6.
The bushing 9 is adapted to serve as a bearing for a shaft 14 with a disc 15, which is provided with reflecting and non-reflecting sections, respectively, preferably on both sides. Thus, the disc 15 may serve as a tachometer disc so that the rotary speed of the shaft 14 can be detected by means of the light element 12. The element may serve as an ordinary switch by rotation of the disc between two positions in which the reflection properties differ. As shown in FIG. 5, the disc 15 may also be provided with wind cups 16 so that the disc and the cups in combination serve as an anemometer.
FIG. 6 shows another element for the building set of the invention, said element consisting of a light conductor rod 17, whose one end 18 is adapted to be received and retained in the hole 6 (FIG. 2). In FIG. 6, the light conductor rod 17 is shown in connection with a liquid vessel 19, the reflection conditions at the other end of the light conductor rod being highly dependent upon whether the liquid surrounds the end of the light conductor or is present at a lower level. The liquid level in the vessel 19 may thus be detected by means of the building element of the invention.
FIG. 7 shows an additional reflecting building element for the building set of the inventon. The building element in FIG. 7 consists of an element corresponding to FIG. 1, but with line codes 20 on one side of the element. An example of the use of the latter element is schematically shown in FIG. 8, which shows an oblong beam 21 on which three elements 22-24 of the type shown in FIG. 7 are placed. Further, two elements of the invention 25 and 26 are shown, which are optically coupled to the line codes on the blocks 22-24 via light conductor cables 27 and 28, respectively, the optical cables being secured by respective holders 29 and 30, respectively. It is noted that, as previously mentioned, the line codes might consist of depressions in the element if laser light means are used.
The building elements shown in FIG. 8 might conceivably be incorporated e.g. in a model of a car with autocatic steering gear comprising the beam 21. The beam 21 may thus be movable in its longitudinal direction with respect to the chassis of the car, while the holders 29 and 30 are stationary with respect to the chassis. The detector elements 25 and 26 may be placed on a stationary or on a movable part of the car because of the flexible light conductor cables 27 and 28. It will thus be appreciated that, through the electric information from the detector elements 25 and 26, positional information may be generated for the steering gear by scanning the line codes present on the building elements 22-24. It will be sufficient with a single detector element 25 which may be connected to a control computer coded to interpret the line code information, but the information may be made more selective by using serveral detector elements 25, 26. The associated computer may optionally be coded to respond to a pre-determined code pattern, and by mechanically changing the shown line code elements 22-24 or by changing the position of the elements various control characteristics for the constructed mode may be provided with the predetermined interpretation in the computer.
FIG. 9 schematically show another use of the building set of the invention, and this use may be related to the steering gear for a car model as explained in connection with FIG. 8. The element 31 represents the detector element described previously which is turned so that the light is transmitted downwardly toward a path 32 provided on a lain and consisting of a solid line and a broken line closely spaced from each other. Since the element 31 is firmly mounted on the car, it may be detected by means of generally known electronic equipment how the vehicle is positioned with respect to the path 32 on the lane. This information may be used for generating a steering signal to the steering gear, which may be designed as explained in connection with FIG. 8. The code lines 33 across the direction of travel may be placed in order for the steering system to receive information on how far the car as reached along the distance determined by the path 32. Optionally, the code lines 33 may also inform the steering system to steer along another path 34.
It has almost been presupposed in the above explanations that digital signals are generated from the detector element. However, it should be noted that nothing prevents detection of an analong signal, since this is just a matter of the design of the electric circuit detecting the current consumption of the light source.
FIGS. 10-13 show some other representations of an embodiment of the detector element of the invention, the figures showing an element seen from below, from the side, from above and in section along the line XI--XI in FIG. 11, respectively. The reference numerals used in connection with FIGS. 2 and 3 are also used in FIGS. 10-13, and it will thus be seen from FIG. 10 that the base of the plate 8 is provided with a pair of coupling tubes 35, 36 which constitute the previously mentioned complementary coupling means for coupling studs on an adjacent element. FIG. 13 shows some details for the position of the insert 7 in the housing 3, it being seen how the bushing 9 at the top engages some stops within the housing 3. It will be appreciated that the shown embodiment just serves as an example. | A toy building set of the type having elements with projections on one surface for engagement with apertures on a surface of another element is provided with detection elements for receiving light energy reflected from bar code elements. The detection elements and the bar code elements are also provided with at least one of the projections or apertures on a surface thereof to permit those elements to be mechanically coupled to other elements of the building set. | 0 |
GENUS AND SPECIES OF PLANT CLAIMED
[0001] Buddleia hybrid Franch.
VARIETY DENOMINATION
[0002] ‘PIIBD-III’
BACKGROUND OF THE INVENTION
[0003] The present invention relates to a new and distinct cultivar of Buddleia plant, botanically known as Buddleia hybrid Franch., commonly known as butterfly-bush, and hereinafter referred to by the cultivar name ‘PIIBD-III’. ‘PIIBD-III’ is grown primarily as an ornamental for landscape use and for use as a potted plant.
[0004] ‘PIIBD-III’ originated from an open-pollination of the cultivar ‘Miss Ruby’ (U.S. Plant Pat. No. 19,950) growing in Watkinsville, Ga. in 2010. The cultivar ‘PIIBD-III’ originated and was selected in a cultivated environment in Watkinsville, Ga. from the progeny of this open-pollination by continued evaluation for growth habit, foliage and flower characteristics.
[0005] Asexual reproduction of ‘PIIBD-III’ by stem cuttings in Watkinsville, Ga. since 2011 has shown that all the unique features of this new Buddleia , as herein described, are stable and reproduced true-to-type through successive generations of such asexual propagation.
SUMMARY OF THE INVENTION
[0006] Plants of the new cultivar ‘PIIBD-III’ have not been observed under all possible environmental conditions. The phenotype may vary somewhat with changes in light, temperature, soil and rainfall without, however, any variance in genotype.
[0007] The following traits have been observed and represent the characteristics of the new cultivar. In combination these characteristics distinguish ‘PIIBD-III’ from all other varieties in commerce known to the inventor. 1. Compact, rounded to upright growth habit; 2. Dark gray-green foliage; 3. Violet, deliciously sweet fragrant flowers with an orange center; 4. Long flowering season, with flowers produced from spring to the first frost.
[0008] ‘PIIBD-III’ is distinguished from its female parent, ‘Miss Ruby’ (U.S. Plant Pat. No. 19,950), by its foliage and flower color. ‘PIIBD-III’ has violet flower color and dark gray-green foliage, whereas ‘Miss Ruby’ has reddish pink flower color and dark green leaves.
[0009] ‘PIIBD-III’ can be compared to ‘Empire Blue’ (Not Patented), but differs in the following characteristics. ‘PIIBD-III’ has smaller foliage, darker violet flower color and compact habit, whereas ‘Empire Blue’ has larger foliage, violet-blue flower color and larger, open, splaying habit.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The accompanying color photographs illustrate the flower and foliage characteristics and the overall appearance of ‘PIIBD-III’, showing the colors as true as it is reasonably possible to obtain in color reproductions of this type. Colors in the photographs may differ slightly from the color values cited in the detailed botanical description which accurately describe the colors of the new Buddleia.
[0011] FIG. 1 illustrates the overall appearance of a three-year-old plant of ‘PIIBD-III’ planted in the ground.
[0012] FIG. 2 illustrates a close-up view of the inflorescences of ‘PIIBD-III’.
[0013] FIG. 3 illustrates the upper surface of a leaf of ‘PIIBD-III’.
[0014] FIG. 4 illustrates the underside of a leaf of ‘PIIBD-III’.
DETAILED DESCRIPTION
[0015] In the following description, color references are made to The Royal Horticultural Society Colour Chart, 2007, Fifth Edition, except where general terms of ordinary dictionary significance are used. The plant used for the description was three-years-old and was grown in the ground in a nursery in Watkinsville, Ga. Colors are described using The Royal Horticultural Society Colour Chart (R.H.S.).
Botanical classification: Buddleia hybrid Franch. ‘PIIBD-III’. Parentage: Female, or seed, parent: ‘Miss Ruby’ (U.S. Plant Pat. No. 19,950). Male, or pollen parent: unknown (open-pollinated). Propagation: terminal cuttings. Time to initiate roots, summer: about 21 days at 32° C. Plant description: Deciduous flowering shrub; compact, rounded to upright growth habit. Freely branching; pruning enhances lateral branch development.
Root description .—numerous, fibrous and well-branched. Plant size .—about 152 cm high from the soil level to the top of the inflorescences and about 137 cm wide. First year stems have a diameter of about 3-4 mm. Shape: quadrangular when young, becoming rounded with age. Pubescence: tomentulose when young, becoming glabrous with age. Second year and older stems have a diameter of about 5 mm or more. Shape: round. Trunk diameter.— 3.8 cm at the soil line. Color: 199B. Internode length .—about 6.5 cm. Strength .—flexible when young, becoming stronger and woody with age. First year stem color ( young ).—198B. Color (mature): 194C. Second year and older stem color.— 199C. Bark does not exfoliate.
Vegetative buds: Opposite arrangement, naked, subglobose, 2 bud scales with tomentulose pubescence. Color: 196D. Size: about 2 mm in length and 1 mm in width. Foliage description:
Arrangement .—opposite, simple. Leaf length: about 7.5 cm. Leaf width: about 3 cm. Shape: lanceolate to elliptical. Apex: acuminate. Base: cuneate. Margin: closely serrate to serrulate. Texture .—upper surface is glabrous, lower surface is tomentose. Venation pattern .—pinnate. Venation color (upper surface): 136A. Venation color (lower surface): 188B. Foliage color ( upper surface ).—136A. Foliage color (lower surface): 188B. Petiole length .—about 4 mm. Petiole diameter: about 2 mm. Petiole color: 140D. Pubescence .—tomentulose.
Flower description: Flowers on new growth. Flowers are produced from about May through the first frost in Watkinsville, Ga. An inflorescence is showy for about three weeks, and individual flowers last about three days and are self-cleaning. Approximately 250-300 flowers per individual inflorescence.
Inflorescence type .—terminal panicle. Inflorescence length: about 14 cm. Inflorescence width: about 4.5 cm. Fragrance: pleasant and sweet. Peduncle .—about 13 cm in length, about 3 mm in diameter, color is 188C, at times overlaid with 178A, with tomentulose pubescence. Individual flowers .—about 1.5 cm in height and 8 mm in diameter and salverform in shape. Flower buds .—Length: about 1 cm; Diameter: about 1.5 mm; Color: N89A. Shape: elongated, linear balloon. Pedicels .—about 3 mm in length, less than 1 mm in diameter, 122C in color with tomentulose pubescence. Calyx .—consists of 4 sepals fused at the base. The calyx is about 3 mm in length, about 1 mm in diameter, 147D in color, tubular in shape with tomentulose pubescence. The individual sepals are lanceolate in shape, with an acute apex and entire margin, 147D in color with tomentulose pubescence.
Petals:
Arrangement/appearance.— 4 petals fused at the base to form the corolla tube, which is about 7 mm in length, 1 mm in width, outer surface is N87A in color and the inner surface or center of the flower is N163B in color. Petal .—Length: about 4 mm. Width: about 4 mm. Shape: broad spatulate. Apex: broad obtuse to rounded. Margin: ruffled. Texture: glaucous. Petal color .—upper and lower surfaces are N87A in color.
Stamens:
Quantity/arrangement.— 4 stamens per flower, fused to the inner base of the corolla tube, about 4 mm long. Filaments: 3 mm in length, less than 0.5 mm in width, and 1D in color. Anthers: 1 mm in length, 0.5 mm in width, and 4C in color. The stamens are not pubescent. Pollen: produced in small quantities and is 158D in color.
Pistils:
Quantity .—One superior pistil per flower. Pubescence: none. Pistil: about 5 mm in length and about 1 mm in width. Stigma: elongated shape, about 1.5 mm in length and 0.5 mm in width and 138C in color. Style: tubular in shape, about 1 mm in length, less than 0.5 mm in width and 138C in color. Ovary: ovoid in shape, about 2.5 mm in length, about 1 mm in width and 138C in color.
Fruit:
Type/appearance .—two-valved, septicidally dehiscent capsule. Length: about 7 mm. Width: about 2 mm. Immature color: 143C. Mature color: 200D. Each capsule contains many tiny seeds 165D in color.
Disease/pest resistance: ‘PIIBD-III’ has not exhibited any particular pest or disease susceptibility or resistance, except occasional susceptibility to spider mites under very hot and dry conditions. is cold hardy to USDA Hardiness Zones 6-9. | A new and distinct cultivar of Buddleia plant named ‘PIIBD-III’, characterized by its compact, rounded to upright growth habit, dark gray-green foliage, violet, deliciously sweet fragrant flowers with an orange center, and long flowering season, with flowers produced from spring to the first frost. | 0 |
This is a division of application Ser. No. 415,742, filed Oct. 2, 1989, now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to a process and apparatus for producing an In-O or In-Sn-O based transparent conductive film (which will be hereinafter referred to as an ITO film) used for a display element for a liquid crystal display o the like.
PRIOR ART
There are conventionally known processes for producing such a transparent conductive film such as coating, vacuum deposition, and gas-phase reaction processes, as well as sputtering processes, including a DC or RF double-pole sputtering and a DC or RF magnetron sputtering. Among these producing processes, the sputtering processes are often used because they enable a transparent conductive film to be formed uniformly on a large-sized substrate.
It is known that the temperature of a substrate and the partial pressure of oxygen are factors affecting the electrical resistivity of a transparent conductive film produced by the sputtering process. It has been understood that the higher the substrate temperature, the lower the electrical resistivity of the resulting film. On the other hand, for the partial pressure of oxygen, it has been understood that in a region of lower oxygen partial pressure, the density of a carrier is larger, and the mobility is smaller because there are many vacancies of oxygen in such a region. Whereas in a region of higher oxygen partial pressure, the density of a carrier is smaller and the mobility is larger. Thus, there is an optimal partial pressure of oxygen that will result in an electrical resistivity of a minimum value from an even balance of the density and the mobility. Thus, it was a practice in the prior art sputtering process to form a transparent conductive film having a lower electrical resistivity wherein parameters of the substrate temperature and the partial pressure of oxygen gas were controlled.
In the prior art sputtering process, the reduction in the electrical resistivity of a transparent conductive film was limited when it is impossible to increase the temperature of a substrate. An example is the case of a full color STN system, wherein an ITO film is formed on a substrate of a color filter material having a heat-resistant temperature as low as 160 to 200° C.
Additionally, the prior art process also has the problem of nonconsistent electrical resistivity. This occurs when the sputtering is continuously carried out, resulting in an insulating oxide of In-O being produced on a surface of a target, thus discoloring the surface to black (such a discoloration will be referred to as blackening). With an increase of the blackening of the target, the electrical resistivity of a transparent conductive film formed on the substrate may be increased. Therefore, when a transparent conductive film is continuously formed on each of a plurality of substrates, for a long period of time, the electrical resistivity of the resulting film may be gradually increased. Thus, it was impossible to provide a transparent conductive film having a consistent electrical resistivity.
It is an object of the present invention to provide a process and apparatus for producing a transparent conductive film, wherein the above problems are overcome.
SUMMARY
The present inventors have made zealous studies to accomplish the above stated object and consequently have found that, in addition to the substrate temperature and the partial pressure of oxygen as factors affecting the electrical resistivity of a transparent conductive film formed on a substrate, the sputtering voltage greatly affects the electrical resistivity of a resulting transparent conductive film.
The present invention has been made on the basis of such knowledge and, according to the present invention, there is provided a process for producing an In-O or In-Sn-O based transparent conductive film by a sputtering process, wherein sputtering is effected at a sputtering voltage of 350V or less.
Reduction in the sputtering voltage is related to a reduction in the discharged impedance (target voltage/target current). For example, the discharged impedance is influenced by the intensity of a magnetic field on the surface of a target, i.e., if the magnetic field intensity is increased, the density of plasma is increased, resulting in a reduced sputtering voltage. In this case, sputtering may be carried out under conditions wherein the intensity of a magnetic field on the surface of a target is maintained at 400 Oe or more.
Additionally, if sputtering is continuously carried out for a long period of time, the surface of a target may be blackened and the sputtering voltage is accordingly increased. In this case, sputtering may be carried out under conditions wherein the intensity of the magnetic field may be adjusted to maintain a constant sputtering voltage during sputter formation of a film.
According to the present invention, targets for a transparent conductive film formed on a substrate include In, an In-Sn alloy, a sinter of In oxide, a sinter of In-Sn oxide, etc. Among them, the sinter of In-Sn oxide is preferred because its use in the formation of a transparent film on a substrate results in the film remaining in a stable state for a long period of time.
Sputtering gases include, for example, a mixed gas comprising an inert gas, such as argon gas, and an oxygen containing ga added thereto. When argon gas is used as an inert gas, the pressure of the mixed gas may be generally of the order of 10 -3 Torr, and the partial pressure of the oxygen gas may be generally of the order of 10 -5 Torr.
In the sequence for forming an In-O or In-Sn-O based transparent conductive film in a sputtering manner, an anion such a O - , O 2- or InO - is generated in the vicinity of the surface of a target. If the target voltage is, for example, -400V, these anions may be accelerated by an energy of 400 eV to smash into a substrate, thereby providing micro-damages to the transparent conductive film that is being formed. When a divalent ion such as In 2+ and Sn 2+ is generated by the micro-damages, which acts as an acceptor, the density of a carrier may be reduced. When the oxygen vacancies are collapsed, the density of a carrier may be also reduced. The reduction in density of a carrier will cause an increase in the electrical resistivity.
According to the present invention, sputtering is carried out at a sputtering voltage of 350V or less (equal to the target voltage), which suppresses to a lower level, the energy of an anion smashing into the substrate, thereby reducing the damage to a resulting transparent conductive film.
Additionally, according to the present invention, there is provided an apparatus for producing an In-O or In-Sn-O based transparent conductive film on a substrate, by a plasma dischargement generated between the substrate and a target, both for which are mounted in opposition to another within a vacuum chamber. An electromagnet, for adjusting the intensity of a magnetic field, is placed rear side on the surface of the target and a magnet controller, for controlling an electric current supplied to the electromagnet, in accordance with a change in sputtering voltage, is provided so as to be connected to a DC power source for the electromagnet.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view of one embodiment of an apparatus for carrying out a process for producing a transparent conductive film according to the present invention.
FIG. 2 is a characteristic graph illustrating the relationship between the magnetic field intensity of magnetron and the DC sputtering voltage.
FIG. 3 is a characteristic graph illustrating a relationship between the DC sputtering voltage and the electrical resistivity under conditions of individual temperatures of a substrate.
DETAILED DESCRIPTION
The present invention will now be described by way of an embodiment with reference to the accompanying drawings.
FIG. 1 illustrates one embodiment of an apparatus for producing a transparent conductive film. In FIG. 1, the reference numeral 1 denotes a vacuum chamber that is designed so that the vacuum degree of the interior thereof is adjustable through an exhaust port 2, connected to suitable evacuating means such as an external vacuum pump, and so that a sputter gas,, for example, one consisting of a mixed gas of argon and oxygen, can be introduced into the vacuum chamber 1 through a gas inlet pipe 3 communicating with the vacuum chamber 1. In the vacuum chamber 1, a substrate 4 and a sputter cathode 5 are disposed in an opposed relation, and a heater 6 is mounted behind the substrate 4 for heating the latter.
A target 8, bonded by a brazing material, is disposed on a front surface of a backing plate 7 of the sputter cathode 5, and a cathode case 11, housing therein an electromagnet 10 connected to a plasma discharging DC power supply 9 having a voltmeter, is disposed behind the backing plate 7 of the sputter cathode. The vacuum chamber 1 and the cathode case 11 are connected through the plasma discharging DC power supply 9, so that when the vacuum chamber 1 is at earth potential, a negative voltage can be applied to the cathode case 11 to effect a DC magnetron sputtering within the vacuum chamber 1.
In the illustrated embodiment, a controller 13 is connected to the plasma discharging DC power supply 9 and a DC power supply 12 for the electromagnet. The controller 13 is capable of receiving variation signals corresponding to variations in sputtering voltage supplied from the plasma discharging DC power supply 9, and controlling a current to the DC power supply 12 for the electromagnet in accordance with the variation signal. This adjusts the magnetic field intensity generated on a surface of the target 8 within the range of 250 Oe to 1,600 Oe.
In FIG. 1, the reference numeral 14 is an earth connected to the vacuum chamber 1; the number 15 is an insulating sheet made of a Teflon plate disposed between the vacuum chamber 1 and the cathode case 11; the numeral 16 is an earth shield; and the numeral 17 is an anti-deposition plate.
It should be noted that while not shown, the target 8 is cooled by water cooling means mounted within the cathode case 11
Specified examples for forming a transparent conductive film will be described below.
EXAMPLE 1
Mounted within the vacuum chamber 1 in the producing apparatus described above and shown, were a substrate 4 made of a light transmittable glass (No. 7059 made by Corning Co. Corp., and having a size of 210 mm ×210 mm), and an oxide target 8 comprising In 2 O 3 containing 10% by weight of SnO 2 incorporated therein (having a size of 125 mm ×406 mm). Then, the vacuum chamber 1 was evacuated by the evacuating means, through the exhaust port 2, to a degree of 8 ×10 -6 Torr. After which a sputtering gas consisting of argon and oxygen gases was introduced into the vacuum chamber 1 through the gas inlet pipe 3, so that the pressure of the interior of the vacuum chamber 1 was 5 ×10 -3 Torr. In this case, the partial pressure of the oxygen gas was 4 ×10 -5 Torr, and the distance between the substrate 4 and the target 8 was 80 mm.
Then, the DC magnetron sputtering was carried out, while the current supplied, from the DC power supply 12, to the electromagnet 10, by the controller 13, was controlled to vary the intensity of the magnetic field, at a central site between magnetic poles, generated on the surface of the target 8, i.e., magnetic field intensity of the magnetron field varied from 250 oe to 1,600 Oe. Further, the sputtering voltages were respectively determined at the following two stages of the sputtering: an initial stage of the sputtering (when the surface of the target material was not yet blackened, i.e., before the target blackened), and a stage after 40 hours of sputtering had lapsed (when the surface of the target material had been blackened, i.e., after the target blackened).
In each of the stages, the sputtering voltage was measured for every magnetic field intensity (magnetic field intensity of magnetron), and the obtained results of measurement are shown in FIG. 2.
As apparent from FIG. 2, it was confirmed that in any of the initial sputtering stage and the stage after 40 hours of sputtering had lapsed, the sputtering voltage was reduced as the magnetic field intensity was increased. In any case, when the magnetic field intensity exceeded 900 Oe, the measured voltage of each of the obtained sputtering voltages showed a tendency not to further decrease.
Accordingly, it is possible to maintain the sputtering voltage constant by varying the intensity of the magnetic field on the surface of the target (in the direction of the arrow as shown in FIG. 2).
The sputtering was also carried out in an RF magnetron sputtering manner instead of the DC magnetron sputtering manner, and similar results were obtained.
EXAMPLE 2
Mounted within the vacuum chamber 1, in the producing apparatus described above and shown, were a substrate 4 made of a light transmittable glass (No. 7059 made by Corning Co. Corp., and having a size of 210 mm ×210 mm), and an oxide target 8 comprising In 2 O 3 containing 10% by weight of SnO 2 incorporated therein (having a size of 125 mm ×406 mm). Then, the vacuum chamber 1 was evacuated by the evacuating means, through the exhaust port 2, to a degree of 8 ×10 -6 Torr. After which a sputtering gas consisting of argon and oxygen gases was introduced into the vacuum chamber 1 through the gas inlet pipe 3, so that the pressure of the interior of the vacuum chamber 1 was 5 >10 -3 Torr. In this case, the distance between the substrate 4 and the target 8 was 80 mm.
Then, the temperature of the substrate 4 was set at room temperature (25° C.), 160° C. and 460° C., respectively, by heating the substrate with a heater 6. The DC magnetron sputtering was conducted at each of such temperatures, while varying the current supplied from the DC power supply 12, to the electromagnet 10, by way of the controller 13, to adjust the intensity of the magnetic field generated on the surface of the target 8, and while varying the sputtering voltage in accordance with the adjustment of the magnetic field intensity, resulting in the formation of an In-Sn-O based transparent conductive film having a thickness of 1,000 Å on the substrate 4.
In this case, the partial pressure of oxygen gas was adjusted so as to optimize the conditions of the substrate temperatures and the sputtering voltages.
The electrical resistivity of the transparent conductive film formed in the above process was measured for every sputtering voltage at every substrate temperature. The obtained results of measurement are shown in FIG. 3.
As apparent from FIG. 3, it was confirmed that, at all the substrate temperatures, the electrical resistivity of the transparent conductive film could be reduced as the sputtering voltage was reduced.
Additionally, the sputtering was also carried out using as a target, an oxide material of a composition comprising In 2 O 3 and SnO 2 incorporated therein in an amount other than 10% by weight, alternatively using an oxide material comprising In 2 O 3 and 10% by weight of SnO 2 therein, as well as using In material alone or an In-Sn alloy as a target in place of the oxide material. Similar results were obtained in all of the above cases.
As previously discussed, in the above process for producing a transparent conductive film, sputtering is effected at a voltage 350V or less (equal to a target voltage). Therefore, there are the following effects: In sputtering the target to form a transparent conductive film on the substrate, the energy of an anion can be reduced, and the damage to the transparent conductive film can be also reduced so that a transparent conductive film, having a lower electrical resistivity, can be formed even on a substrate of a material having a lower heat-resistant temperature.
Additionally, when sputtering is carried out with the intensity of the magnetic field generated on the surface of a target being maintained at 400 Oe or more, a transparent conductive film having a lower electrical resistivity can be easily formed. This is because the sputtering voltage, during formation of the film, can be reduced only by adjustment of the intensity of magnetic field.
Further, even when sputtering is continuously carried out for a long period of time, it is possible to produce a transparent conductive film, having a consistently uniform electrical resistivity, by adjusting the intensity of the magnetic field to maintain the sputtering voltage constant during the formation of a film.
In the apparatus for producing a transparent conductive film according to the present invention, the electromagnet for adjusting the magnetic field intensity on the surface of the target is mounted on the back side of the target, and the controller for controlling the current to the electromagnet, in accordance with variation in sputtering voltage, is connected to a DC power supply for said electromagnet. Therefore, it is possible to maintain a lower sputtering voltage constant, thus leading to the effect that a transparent conductive film, having a lower electrical resistivity, can be easily produced. | A process and apparatus for producing an In-O or In-Sn-O based transparent conductive film by a sputtering process is provided. The sputtering voltage is kept constant at 350V or less by maintaining the intensity of the magnetic field on the surface of the target at 400 Oe or greater. The apparatus contains a vacuum chamber wherein the substrate and target are mounted in opposite to each other. An electromagnet, used for adjusting the intensity of the magnetic field is located on the rear surface of the target. Additionally provided is a controller for the electric current supplied to the electromagnet. The controller is also connected to a DC power supply for the electromagnet. | 2 |
FIELD OF THE INVENTION
This invention relates to a method for preparing diaryliodonium fluoroalkyl sulfonate salts by a one-pot process which does not involve counter ion exchange, and to salts made by the method. Preferably, the salts are diaryliodonium trifluoromethanesulfonate ("triflate") salts. The invention also relates to certain novel diaryliodonium fluoroalkyl sulfonate salts themselves.
BACKGROUND OF THE INVENTION
Iodonium salts are important components of many imaging systems. They are useful for in-situ photochemical production of strong protic acids or free radical species which are subsequently used to initiate polymerizations or depolymerizations, or to react with an acid-sensitive functionality. Generally, they are thermally stable and photochemically labile, which is an ideal situation for imaging applications such as printing plates, lithographic films, and proofing systems, as well as for curing of, e.g., epoxide-type resins.
Symmetrical iodonium salts known in the art are commonly prepared by coupling an aromatic compound with iodate (e.g., potassium iodate), acetic anhydride, and sulfuric acid to yield a diaryliodonium bisulfate salt (See Crivello U.S. Pat. Nos. 3,981,897; 4,136,102; 4,151,175; 4,238,394; and 4,529,490 (assigned to General Electric); Beringer, F. M.; Drexler, E. M.; Gindler, E. M.; Lumpkin, C. C. J. Am. Chem. Soc. 1953, vol. 75, p. 2705; Beringer, F. M.; Falk, R. A.; Karniol, M.; Lillien, I.; Masullo, G.; Mausner, M.; Sommer, E. ibid 1959, vol. 81, p. 342; Klemm, E.; Alkahini, G.; Timpe, H. J. DD 290651; Crivello, J. V.; Lam, J. H. W.; Volante, C. N.; et al. J. Radiat. Curing 1977, vol. 4, p. 2; Crivello, J. V.; Lam, J. H. W. J. Polym. Sci. Symp. 1976, vol. 56, p. 383; and Crivello, J. V.; Lam, J. H. W. Macromolecules 1977, 10, 1307). Diaryliodonium bisulfate salts are generally too insoluble and unreactive to be of direct utility, and must be converted to other counter ions, typically by ion exchange procedures. A number of additional methods of preparing symmetrical and unsymmetrical diaryliodonium salts are known; most of them require the use of strong acids. (See Mason, I. Nature 1937, vol. 139, p. 150; Masson, I.; Race, E. J. Chem Soc. 1937, p. 1718; Masson, I.; Hanby, W. E. ibid. 1937, p. 1699; Masson, I. Argument, C. ibid. 1938, p. 1702; Beringer, F. M.; Bachofner, H. E.; Falk, R. A.; Leff, M. J. Amer. Chem. Soc. 1958, vol. 80, p. 4279; Collette, J. D.; McGreer, D.; Crawford, R.; Chubb, R.; Sandin, R. B. J. Amer. Chem. Soc. 1956, vol. 78, p. 3819; JP 63005040 Jan. 11, 1988; EP 119068; Crivello, J. V.; Lee, J. L. U.S. Pat. No. 4,399,071; Fukuyama, J. M.; Lee, J. L., Crivello, J. V. U.S. Pat. No. 4,992,571; Dektar, J. L.; Hacker, N. P. J. Org. Chem. 1990, vol. 55, p. 639; Research Disclosure RD 350042 1993; Crivello, J. V. U.S. Pat. No. 4,329,300 (May 11, 1982); Koser, G. F.; Wettach, R. H.; Smith, C. S. J. Org. Chem. 1980, vol. 45, p. 1543; Koser, G. F.; Wettach, R. H. U.S. Pat. No. 4,348,525 (Sep. 7, 1982); Koser, G. F.; Wettach, R. H. U.S. Pat. No. 4,826,635 (May 2, 1989); Crivello, J. V. U.S. Pat. No. 5,073,643 (Dec. 17, 1991); Crivello, J. V. U.S. Pat. No. 5,079,378 (Jan. 7, 1992); Kitamura, T.; Matsuyuki, J-i.; Nagata, K.; Furuki, R.; Taniguchi, H. Synthesis, 1992, vol. 10, p. 945; Dalziel, J. R.; Carter, H. A.; Aubke, F. Inorg. Chem 1976, vol. 15, p. 1247; Stang, P. J.; Zhdankin, V. V.; Tykwinski, R. Tetrahedron Lett. 1991, vol. 32, p. 7497; Stang, P. J.; Zhdankin, V. V.; Tykwinski, R. Tetrahadron Lett. 1992, vol. 33, p. 1419; Stang, P. J.; Tykwinski, R.; Zhdankin, V. V. J. Hetrocycl. Chem. 1992, vol. 29, p. 815; and U.S. Pat. No. 5,277,767. According to Miller, R. D. U.S. Pat. No. 4,786,441: "The prior art methods of preparation involve an exchange reaction between lithium triflate and the corresponding onium halide with the reaction being an equilibrium one taking place in an aqueous or mixed aqueous-organic medium. There is no force driving the equilibrium reaction in either direction and in general, the process is inefficient." When sulfuric acid is used, the previously mentioned bisulfate salts are formed.
Exchange of the bisulfate counter ion for a more useful counter ion, such as hexafluorophosphate, trifluoromethanesulfonate (hereinafter referred to as "triflate"), or p-toluenesulfonate can be effected by treatment of the bisulfate with an aqueous mixture of, e.g., the sodium or potassium salt of the corresponding desired acid. However, this exchange reaction can present difficulties if the desired salt is somewhat soluble in the aqueous reaction mixture. In these cases the exchange reaction cannot be forced to completion by precipitation of the exchanged salt, and an undesirable mixture of salts is obtained. It is known in the art to treat diaryliodonium bisulfate salts with aqueous sodium chloride to obtain the corresponding chloride salt, which is quite insoluble in the reaction mixture, thus precipitating out of solution and forcing completion of the exchange reaction. Exchange of the chloride counter-ion to a more useful counter-ion such as the triflate can be effected by treatment with the corresponding desired acid (or silylester). (See Dektar, J. L., Hacker N. P., J. Org. Chem., 1990, 55, 639; Research Disclosure RD 350042 1993; Beringer, F. M.; Drexler, E. M., Gindler, F. M., Lumpkin, C. C. J. Am. Chem. Soc., 1953, vol. 75, p. 2705) This exchange reaction is forced to completion by the elimination of hydrochloric acid (or trimethylsilyl chloride). This process works well to prepare the desired diaryliodonium salts but it requires isolation of the diaryliodonium chloride and an additional exchange reaction.
Thus, there has not been provided a convenient, simple and safe process for the preparation of useful diaryliodonium triflate salts.
SUMMARY OF THE INVENTION
We have discovered a convenient, simple, safe and efficient one-pot method for the synthesis of diarlyiodonium fluoroalkyl sulfonate salts which does not involve sulfuric acid and which eliminates the need for any counter-ion exchange processes.
One aspect of the present invention is a novel method of making a diaryliodonium fluoroalkyl sulfonate salt comprising the steps of:
(a) forming a mixture comprising
(i) an aromatic compound which is optionally substituted with one or more groups selected from the group consisting of electron-neutral groups, electron-donating groups, and combinations thereof, wherein the aromatic compound has at least one pendant --H, and wherein the aromatic compound is unreactive with a fluoroalkyl sulfonic acid(s) of element (b);
(ii) an anhydride selected from the group consisting of aliphatic anhydrides, alicyclic anhydrides, and mixtures thereof, wherein the anhydride is optionally substituted with one or more groups unreactive with the fluoroalkyl sulfonic acid(s) of element (b), and wherein the anhydride is derived from an acid having a pka of greater than about 4.2;
(iii) an alkali metal salt of iodic acid; and
(iv) optionally, a solvent which is unreactive with elements (i) to (iii);
(b) adding to the mixture, with agitation, the fluoroalkyl sulfonic acid of the formula R 11 --CF 2 --SO 3 H, wherein R 11 is selected from the group consisting of alkyl groups, chlorofluoroalkyl groups, chlorinated alkyl groups, and fluorinated alkyl groups, wherein the fluoroalkyl sulfonic acid is optionally dissolved in a solvent which is unreactive with the fluoroalkyl sulfonic acid, such that reaction occurs but at a rate and a temperature selected to prevent an uncontrolled exothermic reaction; and
(c) allowing the reaction to continue, with agitation, at a temperature selected to prevent uncontrolled exothermic reaction, to form diaryliodonium fluoroalkyl sulfonate salt.
The method of the invention optionally further comprises the step (d) of isolating the diaryliodonium fluoroalkyl sulfonate salt.
The present invention also provides the salts prepared according to the method of the invention.
Preferred salts prepared according to the method of the invention have a formula selected from the group consisting of ##STR2## wherein
m represents an integer of 0 or 1;
L is an electron neutral or electron donating group selected from the group consisting of --O--; --NR 12 --, wherein R 12 represents --H or an alkyl group (typically as C 1-20 alkyl group); and --(CR 13 R 14 ) n -- wherein R 13 and R 14 each independently represents --H or an alkyl group or a substituted alkyl group and n represents an integer of 1 to 2;
R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 and R 10 are each independently selected from the group consisting of electron neutral groups and electron donating groups;
wherein adjacent R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 groups optionally may together form a ring; and
R 11 is selected from the group consisting of halide groups, alkyl groups, chlorofluoroalkyl groups, chlorinated alkyl groups, and fluorinated alkyl groups.
Preferably, R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 and R 10 are independently selected from the group consisting of:
alkyl groups comprising about 1 to about 20 carbon atoms;
halide groups;
substituted amino groups;
aromatic groups;
alkoxy groups;
aryloxy groups;
wherein each of said groups which
R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 and R 10 represent may optionally be substituted as long as the substituents do not substantially alter the overall electronic characteristics of the groups to which they are bonded (i.e., cause them to be electron withdrawing as defined above).
Examples of suitable halide groups include but are not limited to those selected from the group consisting of --F, --Cl, CF 3 , --CCl 3 , and --C 2 F 5 . Examples of suitable aromatic groups include but are not limited to those selected from the group consisting of phenyl, naphthyl, tolyl, xylyl, and mesityl. Examples of suitable alkoxy groups include but are not limited to those selected from the group consisting of methoxy, ethoxy, and isopropoxy. Examples of suitable substituted amino groups include but are not limited to those selected from the group consisting of alkyl substituted amino groups, carbonyl substituted amino groups, and sulfonyl substituted amino groups. Specific examples thereof include dimethylamino, diethylamino, piperidyl, and morpholino.
Preferably, the method of the invention consists essentially of the steps (a)-(c) and most preferably consists of the steps (a)-(d). Preferably the mixture of element (c) consists essentially of (i)-(iv), most preferably consists of (i)-(iv).
Another aspect of the present invention is a novel diaryliodonium sulfonate salt having the formula: ##STR3## wherein
m, L, R 1 , R 2 , R 3 , R 4 , R 7 , R 8 , R 9 , R 10 and R 11 are as defined above.
DETAILED DESCRIPTION OF THE INVENTION
The method of the invention involves the reaction of the following components: an electron-neutral and/or electron-rich aromatic compound, an anhydride, an alkali metal salt of iodic acid, a fluoroatkyl sulfonic acid, and, optionally, a solvent unreactive towards the fluoroalkyl sulfonic acid.
Aromatic Compounds
Aromatic compounds suitable for use in the method of the invention are selected from the group consisting of unsubstituted aromatic compounds and aromatic compounds bearing only electron-neutral and/or electron-rich (electron-donating) substituents, wherein the aromatic compound has at least one unsubstituted position (i.e. at least one --H). Mononuclear and polynuclear (bicyclic, tricyclic, etc.) aromatic compounds are useful herein. Examples of useful aromatic compounds include but are not limited to those selected from the group consisting of benzene, cumene, cymene, mesitylene, toluene, xylene, napthalene, fluorene, phenanthrene, and mixtures thereof. The aromatic compound must not bear any electron withdrawing groups such as --NO 2 , --CO 2 H, --CN, --CF 3 , --SO 2 H, --SO 2 R (wherein R is an alkyl or aryl group), --SOR (wherein R is an alkyl group or aryl group), etc. One skilled in the art will readily recognize those substituents which are electron-withdrawing and those which are electron-rich or electron-neutral. In the present context, "electron-donating" and "electron-rich are used interchangeably, and refer to substituents whose "sigma plus" value is less than 0.48. In the present context, "electron-withdrawing" refers to substituents whose "sigma plus" value is 0.48 or greater. The "sigma plus" value is a well understood term by those skilled in the art and is further described in Ritchie, C. D.; Sager, W. F. Prog. Phys. Org. Chem 1964, 2, 323. Examples of electron-neutral or electron-rich substituents which may be present on the aromatic rings include, but are not limited to those selected from the group consisting of (a) C 1 to C 20 alkyl groups, wherein the alkyl groups may be linear, branched, or (poly) cyclic, and may themselves bear substituents as long as those substituents do not substantially alter the electronic characteristics of the alkyl group(s); (b) halide groups selected from the group consisting of fluoride, chloride, bromide, and iodide groups; (c) aryl substituted, alkyl substituted, and unsubstituted amino groups including but not limited to those selected from the group consisting of N,N-dialkyl amino, N,N-diaryl amino, and heterocyclic amino groups wherein the heterocyclic amino group is bonded to the aromatic compound via the heterocyclic ring nitrogen, and including amino groups wherein the alkyl and/or aryl groups on the nitrogen atoms may themselves bear substituents as long as those substituents do not substantially alter the overall electronic characteristics of the amino group(s) and/or the heterocyclic amino group(s); (d) aromatic groups including but not limited to those selected from the group consisting of phenyl cumyl, cymyl, mesityl, tolyl, xylyl, naphthyl, fluorenyl, and phenanthrenyl; and (e) alkoxy moleties wherein the alkyl substituents on the oxygen atoms may themselves bear substituents so long as those substituents do not substantially alter the overall electronic characteristics of the ether groups. In the present context, substituents "do not substantially alter the overall electronic characteristics of the group" when the sigma plus value of the substituent is less than 0.48.
Preferably, the aromatic compound is either unsubstituted or is substituted with one alkyl substituent selected from the group consisting of about C 1 to about C 20 alkyl groups, wherein the alkyl groups may be linear, branched or (poly) cyclic, and may themselves bear non-carbon substituent(s) as long as those substituent(s) do not substantially alter the electron characteristics of the alkyl group. It must be noted that a greater amount of fluoroalkyl sulfonic acid must be used according to the method of the invention if the aromatic compounds have substituted amino groups.
Examples of specific aromatic compounds useful according to the method of the invention include but are not limited to diaryl compounds of the formula Ar--(L) m --Ar, wherein Ar represents a substituted or unsubstituted aromatic group including but not limited to those selected from the group consisting of phenyl, naphthyl, cumyl, cymyl, mesityl, tolyl, xylyl, fluorenyl, and phenathrenyl; m represents an integer of 0 to 1; and L is a divalent linking group selected from the group consisting of --(CR 13 R 14 ) n --, wherein R 13 and R 14 are independently selected from the group consisting of --H and alkyl groups (preferably C 1 -C 20 ), and wherein n is an integer selected from the group consisting of 1 and 2 (if n was 3 or greater a low yield would result); --0--; NR 12 -- wherein R 12 is selected from the group consisting of --H and alkyl groups (preferably C 1 -C 20 ).
Such diaryl compounds also form cyclic iodonium salts, wherein the iodine atom is one member of a central five-membered, six-membered or seven-membered ring.
Diarylalkyl compounds particularly useful according to the invention include gem-diaryl compounds such as 1,1-diarylalkyls wherein the aryl moieties are as defined above. Alkyls of this group may be of any chain length from about 1 to about 20 carbon atoms, and may be linear, branched, or (poly) cyclic, and may themselves bear substituents as long as those substituents do not substantially alter the electronic characteristics of the alkyl group(s). Iodonium salts of 1,1-diarylalkyls of the invention form cyclic iodonium salts, wherein the iodine atom is one member of a central six-membered ring, provided the aromatic rings are both substituted in the para positions.
Anhydrides
Anhydrides useful according to the invention are derived from acids which have pkas of about 4.2 or greater, for reasons of good yield, preferably, about 4.5 to about 5.0 for reasons of even better yield and commercial availability. Anhydrides derived from acids which have pkas less than 4.2 result in a poor yield.
Anhydrides useful in the method of the invention are selected from the group consisting of (substituted) aliphatic anhydrides including but not limited to those selected from the group consisting of acetic anhydride, propionic anhydride, butyric anhydride, pentanoic, anhydride, hexanoic anhydride, heptanoic anhydride, octanoic anhydride, decanoic anhydride; (substituted) alicyclic anhydrides including but not limited to, those selected from the group consisting of succinic anhydride, glutaric anhydride, adipic anhydride; and mixtures thereof. Suitable substituents would include those that are unreactive with the other mixture components under reaction conditions. (They should be unreactive with fluoroalkane sulfonic acid.) Examples of suitable substituents include but are not limited to those selected from the group consisting of alkyl, alkoxyl, aryl, halides, etc. Examples of specific suitable substituents include methyl, ethyl, propyl, chloro, bromo, iodo, fluoro, methoxy, ethoxy, aryl, dimethylamino, diethylamine, etc. Unsuitable substituents include those such as alcohols, mercaptans, olefins, acetylenes, primary amines, etc. One skilled in the art would be capable of recognizing those substituents which would be reactive with fluoroalkane sulfonic acid and those which would be unreactive. Preferably, the anhydride is acetic anhydride for reasons of availability.
Alkali Metal Salts of Iodic Acid
As used herein the term "alkali metal" refers to sodium, potassium, lithium, and cesium. Alkali metal salts of iodic acid ("alkali iodates") are a convenient source of iodate for the subject reaction, since the salts dissociate easily and the iodate ion readily displaces hydrogen from aromatic nuclei in electrophilic substitution reactions under acidic reaction conditions. Alkali metal salts useful in the method of invention are selected from the group consisting of potassium iodate, sodium iodate, lithium iodate, cesium iodate, and mixtures thereof. Potassium iodate is preferred because of its availability and ease of handling. In the stoichiometry of the reaction, one-half equivalent of alkali iodate is preferably used for each equivalent of aromatic compound when the aromatic compound is not a diaryl compound such as a gem-diaryl compound. In the latter case, one equivalent of alkali iodate is preferably used for each equivalent of diaryl compound. In cases where the aromatic compound may be expensive or of limited availability, an excess of alkali iodate may be used to ensure relative completeness of the reaction.
Fluorinated Alkyl Sulfonic Acids
Fluoroalkyl sulfonic acids of the formula R 11 --CF 2 --SO 3 H are useful according to the method of the invention, wherein R 11 is selected from the group consisting of alkyl groups (typically C 1-20 ), chlorofluoro alkyl groups (typically C 1-20 ), chlorinated alkyl groups (typically C 1-20 ), and fluorinated alkyl groups (typically C 1-20 ). Preferably perfluoroalkyl groups are present (i.e. perfluoroalkane sulfonic acids). Fluoroalkyl sulfonic acids useful according to the method of the invention provide the sulfonate counterion for the iodonium moiety. Perfluoroalkyl sulfonic acids are described in the Encyclopedia of Chemical Technology, 3rd Edition, Volume 10, pp. 952-955, which reference is incorporated by reference herein. Perfluoroalkyl sulfonic acids have the general formula R f SO 3 H, wherein R r represents a perfluorinated alkyl moiety. Preferably R f represents a perfluorinated alkyl moiety having from about 1 to about 20 carbon atoms, more preferably about 1 to about 10 carbon atoms, for reasons of availability and may constitute a straight chain moiety, a branched chain moiety, or a cyclic moiety. Examples of such acids include but are not limited to those selected from the group consisting of CF 3 CO 3 H, C 2 F 5 SO 3 H, n-C 4 F 9 SO 3 H, n-C 5 F 11 SO 3 H, n-C 6 F 13 SO 3 H, n-C 8 F 17 SO 3 H, ##STR4## Preferably, trifluoromethanesulfonic acid, commonly referred to as "triflic acid," is used according to the method of the invention for reasons of cost and availability.
Optional Solvents
Optionally, a solvent (typically an organic solvent) which is unreactive towards the fluoroalkyl sulfonic acid(s) used and which is itself unreactive under the reaction conditions employed (i.e. strongly acidic and oxidative conditions) may be used according to the method of the invention. Examples of such unreactive solvents include but are not limited to those selected from the group consisting of hydrocarbons, including but not limited to those selected from the group consisting of hexane, pentane, heptane, cyclohexane, octane, mixtures thereof, etc.; chlorinated hydrocarbons, including but not limited to those selected from the group consisting of dichloromethane, chloroform, carbon tetrachloride, dichloroethane, trichloroethane, tetrachloroethane, mixtures thereof, etc.; fluorinated hydrocarbons such as freons; carboxylic acids, including but not limited to those selected from the group consisting of acetic acid, propionic acid, butyric acid, etc. and, we theorize, inorganic solvents such as SO 2 and carbon disulfide. Organic solvents are readily available, unreactive, and have good solubility properties. If an organic solvent is used, the preferred solvent is dichloromethane for reasons of its unreactiveness and solubilizing ability. Inorganic solvents may be useful but would be more difficult to use. In practice, most of the reactants employed in the method of the present invention are liquids and thus solvent may be included but is not necessary in such situations. A solvent is typically added to aid in dissolving the aromatic compounds of the reaction mixture when such aromatic compounds are solids.
Description of the Reaction
The stoichiometry of the reaction requires two equivalents of an aromatic compound (or one equivalent of a diaryl compound), two equivalents of an anhydride, one equivalent of an alkali metal salt of iodic acid and two equivalents of a fluoroalkyl sulfonic acid.
Typically the reaction of the invention involves the use of about 2 to about 10 equivalents of an aromatic compound, about 1 to about 4 equivalents of an anhydride, about 0.5 to 2 equivalents of an alkali metal salt of iodic acid, 0 to about 100% weight of a solvent based upon the weight of the aromatic compound, and about 1 to 3 equivalents of fluoroalkyl sulfonic acid.
Preferably the reaction of the invention involves the use of about 2 to about 3 equivalents of aromatic compound, about 2 to 3 equivalents anhydride, about 1 to 1.5 equivalents of an alkali metal salt of iodic acid, 0 to about 50% weight of a solvent, and about 1.9 to about 2.5 equivalents of fluoroalkyl sulfonic acid.
If too much fluoroalkane sulfonic acid is used the yield of the reaction may be decreased because of the formation of by-products. If too little fluoroalkane sulfonic acid is used the yield of the reaction relative to the alkali metal salt of the iodic acid will decrease. If too much aromatic compound is used the yield of the iodonium triflate relative to the aromatic compound is reduced. If too little aromatic compound is used the yield of the iodonium triflate relative to the aromatic compound is increased.
If too much anhydride is used the yield relative to the anhydride decreases. If too little anhydride is used the yield relative to the anhydride increases.
If too much alkali metal salt of iodic acid is used the yield relative to the alkali metal salt of iodic acid decreases. If too little alkali metal salt of iodic acid is used the yield relative to the alkali metal salt of iodic acid increases.
If too little solvent is used and the aromatic compound (or diaryl compound) is a solid the yield may be reduced. If too much solvent is used the yield of the reaction may be reduced.
The method of the invention involves forming a mixture by combining in any order the aromatic compound, the anhydride, the alkali metal salt of iodic acid, and optional solvent in a suitable reaction vessel such a pyrex or glass lined vessel, due to the acidic conditions. The components are typically combined at a temperature of 0° C. to 25° C. (most typically 25° C.), one atmosphere pressure, and medium agitation (typically about 80 rpm). The temperature of combination should be high enough to facilitate reaction but below the boiling point of any one component.
Typically a mixture of at least about 2 equivalents of a suitable aromatic compound and 1 equivalent of alkali metal iodate in an anhydride such as acetic anhydride is stirred and cooled to typically about -10° C. to 25° C. (preferably about 20° C. or less) and treated with at least 2 equivalents (typically a slight excess, i.e. about 10-20% more) of fluoroalkane sulfonic acid at such a rate as to keep the reaction at a temperature selected to prevent uncontrolled exotherm and maximize yield (typically about 25° C. or below). When addition is complete, the reaction mixture is stirred typically for about 10 to 14 hours at typically about 20° C. to about 40° C. (preferably about 30° C. to about 40° C.) while the reaction continues until the end product is formed and the reaction is at least substantially completed (typically at least about 80% complete, preferably at least about 90% complete). Usually the reaction product contains a few impurities, typically up to about 10% impurities.
The salt may be isolated from the reaction mixture. By isolating it is meant removing some or all of any remaining components other than the diaryliodonium fluoroalkyl sulfonate salt. These components include unreacted starting materials, reaction by-products and solvents.
The resultant reaction mixture is carefully diluted with water (since the resultant reaction mixture contains acid), while maintaining the temperature at or below about 25° C. The desired diaryliodonium fluoroalkyl sulfonate salt is typically isolated from the aqueous phase by admixture with an organic solvent, such as dichloromethane, toluene, ethyl acetate, etc. which may effect precipitation or solution of the salt. If the salt precipitates it is collected by filtration and optionally recrystallized. If the salt remains in the organic solvent, the aqueous phase is removed. The organic phase is optionally extracted with water to remove residual impurities. The organic phase is optionally concentrated in vacuo and the resulting residue is optionally recrystallized.
If the temperature is less than about 20° C. the reaction rate will be slow and the yield low. If the temperature is greater than about 40° C. the product could decompose.
Linear diaryliodonium perfluoroalkane sulfonates of the invention are prepared as follows: A mixture of at least about 2 equivalents of a suitable aromatic compound that cannot form a cyclic iodonium salt by bridging 2 of the aryl groups or 1 equivalent of suitable diaryl compound that can form a cyclic iodonium salt by bridging 2 of the aryl groups, and 1 equivalent of alkali metal iodate in an anhydride such as acetic anhydride is stirred and cooled to typically about -10° C. to about 25° C. (more typically about 20° C. or less) and treated with at least 2 equivalents (typically a slight excess, i.e. about 10-20% more) of fluoroalkane sulfonic acid at such a rate as to keep the reaction at a temperature selected to prevent uncontrolled exotherm and maximize yield (typically about 25° C. or below). When addition is complete, the reaction mixture is stirred for about 10 to about 14 hours at room temperature (typically about 20° C. to about 40° C.) while the reaction continues until the end product is formed and the reaction is at least substantially completed (at least about 80% complete). The resultant reaction mixture is carefully diluted with water (since the resultant reaction mixture contains acid), keeping the reaction temperature at or below about 25° C. The desired diaryliodonium fluoroalkyl sulfonate salt is typically isolated from the aqueous phase by admixture with an inert solvent, such as dichloromethane, which may effect precipitation or solution of the salt. Acyclic products obtained from monosubstituted aromatics are a mixture of the para-para and ortho-para isomers.
EXAMPLES
The invention is further illustrated by the following nonlimiting examples. All parts, percentages, ratios, etc. in the examples and the rest of the specification are by weight unless otherwise specified.
Example 1 - Preparation of 2, 3, 7, 8, 10-pentamethyl-10H-dibenzo[b,e]iodimium trifluoromethanesulfonate.
Into a 250 mL 3-necked round bottom flask equipped with a mechanical stirrer, thermometer, and inlet was charged, with agitation, 30.0 grams (125.8 mmol 1.0 eq) of 1,1-bis(3,4-dimethylphenyl)ethane, 45 mL of acetic anhydride and 26.9 grams (126 mmol, 1.0 eq) of potassium iodate to form a mixture which was cooled to -10° C. Trifluoromethane-sulfonic acid (also referred to herein as "triflic acid" (37.8 grams, 22.3 mL, 252 mmol, 2.0 eq) was added dropwise to the flask at such a rate that the reaction temperature did not exceed 0° C. The mixture was stirred at 0° C. and allowed to warm to room temperature overnight. The reaction mixture was black with a thick precipitate. To the mixture was added approximately 8 mL of water at or below 25° C. followed by methylene chloride. The precipitate that formed was collected and washed with methylene chloride, water, and acetone to give 12.53 grams of crude product. This material was recrystallized from approximately 750 mL of acetone to give 4.71 grams (10% yield) of product having a melting point of 290° C. (decomposes on melting).
Example 2 - Preparation of Ditolyliodonium Trifluoromethanesulfonate.
Into a 2 liter 3-necked round bottom flask equipped with a mechanical stirrer, thermometer, and inlet was charged with agitation 230.394 g (1076.60 mmol) of potassium iodate, 400 g (4341.13 mmol) of toluene and 360 mL of acetic anhydride. The mixture was cooled to -15° C. Trifluoromethanesulfonic acid (325.751 g, 2170.57 mmol) was added dropwise at a rate such that the temperature remained below 5° C. The addition was complete in 2.5 hours. The mixture was allowed to stir for 4 hours at 0° C. The cooling bath was removed and stirring was continued overnight. The mixture was cooled to 0° C. and 537 mL of water was added at such a rate that the temperature remained below 10° C. Dichloromethane (500 mL) was added and the mixture was stirred 30 minutes and allowed to phase split. The dichloromethane phase was separated. To the aqueous phase was added 500 mL of dichloromethane and the mixture was stirred for 30 minutes and allowed to phase split. The dichloromethane phase was separated. The combined dichloromethane phases were concentrated in vacuo at 40° C. to give a brown liquid. Isopropyl ether (800 mL) was added and the mixture was stirred for one hour. The resulting solid was collected by filtration and washed with 800 mL of isopropyl ether. To the solid was added 460 mL of isopropyl alcohol and the mixture was heated to 82° C. for 30 minutes or until the solid dissolved. The solution was diluted with 460 mL of hexane and the mixture was cooled to 0° C. The resulting solid was collected by filtration and washed with a mixture of 200 mL of hexane and 200 mL of isopropyl alcohol. The solid was heated with 460 mL of isopropyl alcohol at 82° C. for 30 minutes or until a homogeneous solution was obtained. The solution was diluted with 460 mL of hexane and the mixture was cooled to 0° C. The solid was collected by filtration and washed with a mixture of 200 mL of hexane and 200 mL of isopropyl alcohol. The solid was then washed with 300 mL of hexane and allowed to air dry to give a white solid (213.92 grams, 43.5% yield, melting point 110-127).
Example 3 - Preparation of Di(dodecylphenyl)iodonium Trifluoromethanesulfonate.
Into a 250 ml 3-neck round bottom flask equipped with a mechanical stirrer, thermometer, and inlet was charged, with agitation, 8.67 grams (40.6 mmol, 0.5 eq) of potassium iodate, 20.0 grams (18.2 mmol, 1.0 eq) of dodecylbenzene, and 40 mL of acetic anhydride to form a mixture. To the mixture was added 12.2 grams (7.19 mL, 81.2 mmol, 1.0 eq) of triflic acid at 0° C. dropwise at such a rate that the reaction temperature did not exceed 0° C. The reaction mixture was allowed to slowly warm to room temperature over about a 14 hour period and then quenched with 20 mL of water at 0° C. while agitation continued. The mixture was extracted with methylene chloride and the methylene chloride layer was washed with sodium bicarbonate until neutral. The methylene chloride layer was concentrated in vacuo and slowly began to thicken. This material was dissolved in approximately 600 mL of hexanes and cooled in dry ice. A precipitate formed and the mixture was filtered and washed with cold hexanes. The precipitate was collected to give 4.9 grams of a waxy flaky solid (13% yield).
Example 4 - Preparation of 4,4'-Di-t-butylbiphenyl.
Into a 250 ml 3-neck round bottom flask equipped with a mechanical stirrer, thermometer, and inlet was charged, with agitation, 40 mL of nitromethane to which was added portionwise 20.7 grams (156 mmol, 1.69 eq) of aluminum chloride with agitation and cooling so as not to exceed 40° C. This solution was added to a mixture of 14.2 grams (92.1 mmol, 1.0 eq) of biphenyl and 26.5 grams (120 mmol, 1.3 eq) of 2,6-di-t-butyl-4-methylphenol in 40 mL of nitromethane at 15° C. over a period of 5 to 10 minutes. The mixture turned a dark opaque color and near the end of the addition, the mixture became very thick. The reaction mixture was allowed to stir for 30 minutes and then poured into ice-water. The mixture was extracted with ether twice and the ether layer was concentrated in vacuo. Additional ether was added to the solid and the mixture was concentrated in vacuo. Toluene was added to the solid and the mixture was concentrated in vacuo. This treatment was to insure removal of nitromethane before washing with base. The brown solid residue was dissolved in ether and washed with approximately 300 mL of 1M sodium hydroxide until the aqueous layer was no longer deeply colored. The organic layer was washed with water and concentrated in vacuo. The brown residue was recrystallized from approximately 150 mL of ethanol to give 10 grams (41% yield). Melting point=129°-130° C.
Example 5 - Preparation of 3,7-Di-t-butyldibenziodolium Trifluoromethanesulfonate.
Into a 250 ml 3-neck round bottom flask equipped with a mechanical stirrer, thermometer, and inlet was charged with agitation, 4.0 grams (18.8 mmol, 1.0 eq) of potassium iodate, 5.0 grams (18.8 mmol, 1.0 eq) of 4,4'-di-t-butylbiphenyl, and 20 mL of acetic anhydride to form a mixture which was cooled to 0° C. To the mixture was added 5.63 grams (3.32 mL, 37.5 mmol, 2.0 eq) of triflic acid dropwise at such a rate that the reaction temperature did not exceed 10° C. The temperature was kept below 10° C. during the addition by the use of a cooling bath. The reaction mixture was never homogeneous and the 4,4'-di-t-butylbiphenyl did not appear very soluble in the reaction mixture. The reaction mixture turned dark almost immediately upon addition of the triflic acid. The mixture was stirred for about 14 hours at room temperature. The reaction was quenched with approximately 60 mL of water and extracted with methylene chloride. The methylene chloride layer was washed with saturated aqueous sodium bicarbonate solution and concentrated in vacuo. The residue was a dark viscous oil. This material was soluble in ether and could be precipitated with hexanes; however, the precipitate was a brown amorphous powder. Titration with acetone gave a tan solid 0.2 gram (2% yield). Melting point=233°-234° C.
Example 6 - Preparation of 1,1-Bis(4-t-butylphenyl)heptane.
Into a 250 ml 3-neck round bottom flask equipped with a mechanical stirrer, thermometer, and inlet was charged, with agitation, 34 mL of nitromethane to which was added portionwise 17.8 grams (134 mmol, 1.7 eq) of aluminum chloride to form a solution with cooling such that the temperature did not exceed 40° C. This solution was added to a mixture of 20.0 grams (79.2 mmol, 1.0 eq) of 1,1-diphenylheptane and 22.8 grams (103 mmol, 1.3 eq) of 2,6-di-t-butyl-4-methylphenol in 56 mL of nitromethane at 15° C. over a period of 5 to 10 minutes. The mixture turned a dark opaque color. The reaction mixture was allowed to stir for 30 minutes at room temperature and was then poured into ice-water. The mixture was extracted with ether twice and the ether layer was concentrated in vacuo. Additional ether was added to the residue and concentrated followed by addition of toluene and concentration. This treatment was to insure removal of the nitromethane before washing with base. The dark oil was dissolved in ether and washed with approximately 400 mL of 1 M sodium hydroxide. The aqueous layer was less highly colored. The organic layer was washed with water and concentrated in vacuo. The residue was distilled in vacuo (1.5-2 mmHg). A forerun of 2,6-di-t-butyl-4-methylphenol was collected. Boiling point 75°-105° C. at 2 mm (Literature Boiling Point=265° C. at 760 mm). The second fraction gave the 15.0 grams product, (55% yield). Boiling point=195°-197° C. at 2 mm.
Example 7 - Preparation of 3,7-Di-t-butyl-10-hexyl-10H-dibenzo[b,e]iodonium Trifluoromethanesulfonate.
Into a 150 ml 3-neck round bottom flask equipped with a mechanical stirrer, thermometer, and inlet was charged, with agitation, 2.9 grams (13.7 mmol, 1.0 eq) of potassium iodate, 5.0 grams (13.7 mmol, 1.0 eq) of 1,1-Bis(4-t-butylpheny) heptane, and 8 mL of acetic anhydride to form a mixture which was cooled to 0° C. To the mixture was added 4.1 grams (2.4 mL, 27 mmol, 2.0 eq) of triflic acid dropwise at such a rate that the reaction temperature did not exceed 0° C. This mixture became thick during the addition. The mixture was stirred at 0° C. and allowed to warm to room temperature over about 14 hours. Approximately 10 mL of water was added to the reaction mixture at 0°-20° C. followed by methylene chloride. The precipitate dissolved in the methylene chloride and the organic phase was washed with water, sodium bicarbonate, and water, and concentrated in vacuo to give a viscous dark amber oil. This material was stirred with hexanes for 3 days and a brown solid residue was collected to give 0.88 gram (10% yield).
Example 8 - Preparation of Di(4-chlorophenyl)iodonium Trifluoromethanesulfonate.
To a mixture of 20.0 grams (178 mmol, 1 eq) of chlorobenzene in 30 mL of acetic anhydride and 19.0 grams (88.8 mmol, 0.5 eq) of potassium iodate cooled to 0° C. was added 26.7 grams (15.7 mL, 178 mmol, 1.0 eq) of triflic acid at such a rate that the reaction temperature did not exceed 0° C. The mixture was allowed to warm to room temperature slowly and stirred for 14 hours. Approximately 45 mL of water was added to the reaction mixture at 0°-20° C. followed by methylene chloride. The precipitate dissolved in the methylene chloride and the organic phase was washed with water, aqueous sodium bicarbonate, and water, and concentrated in vacuo. This material was recrystallized from a mixture of 20 mL of isopropanol and 35 mL of hexane to give 7.62 grams (8.6% yield). A second crop was obtained from the mother liquor, 2.5 grams (total yield 11.4%). The product contains less than 7% of the isomeric 2-chlorophenyl-4-chlorophenyliodonium triflate and a small amount of uncharacterized impurity.
Example 9 - Preparation of 1,1-Bis(4-t-butylphenyl)methane.
A solution of 13.4 grams (100 mmol, 1.69 eq) of anhydrous aluminum chloride in 26 mL of nitromethane was prepared by slowly adding the aluminum chloride to the nitromethane with cooling at 0° C. This solution was added to a mixture of 10.0 grams (59.4 mmol, 1.0 eq) of diphenylmethane and 17.1 grams (77.3 mmol, 1.3 eq) of 2,6-di-t-butyl-4-methytphenol in 28 mL of nitromethane at 15° C. over a period of 5 to 10 minutes. The mixture turned to a dark opaque color. The reaction mixture was allowed to stir for 30 minutes at room temperature and then poured into ice-water. The mixture was extracted twice with ether and the ether layer was concentrated in vacuo. Additional ether was added to the residue and concentrated, followed twice by addition of toluene and concentration. This treatment was to insure removal of the nitromethane before washing with base. The dark oil was dissolved in ether and washed with 1L of 1 M potassium hydroxide until the aqueous layer was no longer colored. Then the mixture was washed with water and concentrated in vacuo. The product was collected at 134°-150° C./0.25 mmHg (12.2 grams, 73% yield).
Example 10 - Preparation of 3,7-di-t-butyl-10H-dibenzo[b,e]iodinium Trifluoromethanesulfonate.
To a mixture of 5.0 grams (17.8 mmol, 1.0 eq) of 1,1-bis(4-t-butylphenyl)methane in 8 mL of acetic anhydride and 3.8 grams (17.8 mmol, 1.0 eq) of potassium iodate cooled to 0° C. was added 5.3 grams (3.2 mL, 36 mmol, 2.0 eq) of triflic acid at such a rate that the reaction temperature did not exceed 0° C. This mixture became thick during the addition. The mixture was stirred at 0° C. and allowed to warm to room temperature overnight. Approximately 10 mL of water was added to the reaction mixture at 0°-20° C. followed by methylene chloride. The precipitate dissolved in the methylene chloride and the organic phase was washed with water, aqueous sodium bicarbonate, and water, and concentrated in vacuo to give a dark solid. This material was triturated with approximately 10 mL of ether and then washed with an additional 10 mL of ether. The residue was then triturated with approximately 20 mL of methylene chloride to give 1.0 grams (10% yield) of product. This material was stable to over 280° C.
Various modifications and alterations of this invention will become apparent to those skilled in the art without departing from the scope and spirit of this invention, and it should be understood that this invention is not to be unduly limited to the illustrative embodiments set forth herein. | The present invention provides a convenient, simple, safe and efficient one-pot method for the synthesis of a number of diarlyiodonium triflate salts which does not involve sulfuric acid and which eliminates the need for any counter-ion exchange processes.
The invention also provides a novel salt of the formula ##STR1## | 2 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This invention claims benefit of priority to U.S. provisional patent application Ser. No. 61/989,979, filed May 7, 2014; the entire content of which is herein incorporated by reference in its entirety.
TECHNICAL FIELD
[0002] The invention relates generally to an apparatus for training of the facial muscles and more specifically to a facial muscle trainer with a minimal number of parts.
BACKGROUND OF THE INVENTION
[0003] Apparatuses for the training of the facial muscles are generally known. Examples of such training devices are contained in document number U.S. Pat. No. 4,280,696 or in document number DE 198 31 294 A1 which stems from the applicant. However, the disclosed solutions still have a rather large number of parts, complicating assembly and resulting in accordingly high costs.
[0004] A solution which stems also from the applicant, but with, however, a reduced number of parts, is disclosed in document number DE 10 2004 016 286 A1, which is explicitly referred to, and the content of which is incorporated by reference herein. Although this solution represents an improvement over the aforementioned embodiments, it still has a rather large number of individual components.
SUMMARY OF THE INVENTION
[0005] The object of the invention is an improvement of the solution as shown in document number DE 10 2004 016 286 A1 in a way that the number of the individual parts is reduced to the most possible extent, without restricting the functionality.
[0006] The object is solved by a facial muscle trainer according to the main claim. Advantageous embodiments can be taken from the dependent claims, the subsequent description, and the figures.
[0007] The above is accomplished through the development of A facial muscle trainer according to the invention for training the facial muscles of a person comprises a C-shaped clamp with two legs which are joined by a joint piece, as well as two bite surfaces being arranged at the ends of the legs. It is characterized in that it has at least one rib at at least one of the two legs running along the longitudinal direction of the leg, increasing the stiffness of the leg.
[0008] In this manner, the additional metal spring which is known from the art and in particular from the above mentioned document number DE 10 2004 016 286 A can be omitted. Thus, one component is dropped which is essential for the embodiments known in the art, and which results in costs on one hand, and which must be assembled on the other. Therefore, the facial muscle trainer according to the invention is more cost effective and further lighter, since the weight of the metal spring is not negligible depending on the desired stiffness.
[0009] Preferable, the facial muscle trainer has at least one rib at each of both legs.
[0010] Particularly preferred, each of the two legs has a multitude of ribs.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is perspective view of an embodiment of the facial muscle trainer according to the invention.
[0012] FIG. 2 is side view of the facial muscle trainer according to FIG. 1 .
[0013] FIG. 3 is a rear view of the facial muscle trainer according to FIG. 1 .
[0014] FIG. 4 is a perspective view of another embodiment of the facial muscle trainer according to the invention.
[0015] FIG. 5 is a sectional view of a leg of the facial muscle trainer according to FIG. 4 .
[0016] FIG. 6 is an elastic body for the facial muscle trainer.
[0017] FIG. 7 is a perspective view of a further embodiment of the facial muscle trainer according to the invention.
[0018] FIG. 8 is a sectional view of a leg of the facial muscle trainer according to FIG. 7 .
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0019] In the following, the invention is described more detailed by aid of the attached drawings. Reference numerals which have already been introduced or which are redundant are partially omitted.
[0020] In FIG. 1 , a perspective view, and in FIG. 2 , a side view of an embodiment of the facial muscle trainer 1 according to the invention is depicted. It has two legs 2 , 3 which are joined to each other by the joint piece 4 . At the ends of the legs 2 , 3 , two bite surfaces 5 , 6 are arranged. These serve for receiving the teeth of the user (not shown), who can train his facial muscles by the repeated opening and closing of the jaw. The facial muscle trainer 1 can have several ribs 7 at both legs 2 , 3 which run along the longitudinal direction of the legs 2 , 3 , and which enhance the stiffness of the respective leg 2 , 3 . By variation of the width of the ribs 7 , they can be influenced with regard to their stiffness, which in turn determines the stiffness of the respective leg 2 , 3 .
[0021] According to a preferred embodiment, the facial muscle trainer 1 has at the inner side of both legs 2 , 3 one or, as depicted, several, then in longitudinal direction of leg 2 , 3 subsequently arranged, mountings 9 for an elastic body 8 , as shown in FIG. 6 (omitted in FIG. 1 and FIG. 2 ).
[0022] According to the depicted embodiment, the bite surfaces 5 , 6 are limited by means of raised structures 10 in direction of the joint piece 4 and in direction of the tip. In this manner, end stops are provided which ensure that the user places his teeth onto the region provided therefore, namely the bite surfaces 5 , 6 . An unintentional slipping off which would result in a shooting up of legs 2 , 3 , thus representing a risk of injure, is therefore largely avoided.
[0023] Preferably, the facial muscle trainer 1 is flattened at the outer region of the joint piece 4 so that it has feet 11 onto which it can be placed. This enables a space saving storage of the facial muscle trainer 1 .
[0024] For the facial muscle trainer 1 depicted in FIGS. 1-3 , the ribs 7 are arranged at the outsides of its legs 2 , 3 . As can be seen in FIG. 3 , the outer ribs 7 can extend also into the region between the feet 11 . Also, such ribs, but being arranged at the inside, are possible (not shown).
[0025] As can also be derived from these figures, the interspaces which are present between ribs 7 are purged with a silicone like material. Thus, a rounded surface is provided, since the ribs 7 which are located in the central region of the legs 2 , 3 are higher than the ribs 7 which are arranged in the border regions of the legs 2 , 3 .
[0026] In this manner, both legs 2 , 3 have at their outside beyond the bite surface 5 , 6 a grip surface for holding with several fingers. By pressing with the fingers of preferably both hands of the user, the jaw force which is necessary for closing the facial muscle trainer can be supported and thus reduced. Further, a secure, slip-free holding of the facial muscle trainer 1 is ensured.
[0027] As can further be derived from the figures, preferably, both legs 2 , 3 are designed identically. Thus, the facial muscle trainer 1 can not be held the wrong way, since upper and under side are identical. This can particularly be seen in FIGS. 2 , 4 and 7 . FIG. 2 further shows overlays from a silicone like material (hatched) which are purged onto the bite surfaces 5 , 6 , which further avoid slipping off of the teeth (not shown), thus further increasing safety.
[0028] In the embodiments shown in FIG. 4 and FIG. 7 , the ribs 7 are arranged at the inner sides of the legs (no reference numeral).
[0029] The embodiment depicted in FIG. 4 shows only one single rib 7 which runs around the inner side, the embodiment depicted in FIG. 7 shows two ribs running around the inside.
[0030] The outsides of these embodiments are kept rather flat and are coated with a slip resistant overlay which has grooves ( FIG. 5 ) or neps ( FIG. 7 ). This can also be derived from the sectional views according to FIG. 5 and FIG. 8 , wherein, however, the interior rib(s) is/are not depicted.
[0031] From FIG. 4 , the positioning of an elastic body 8 which is designed as a spring can be seen. It is arranged between both legs 2 , 3 . Its position is determined by several mountings 9 which are arranged in longitudinal direction one after the other. Depending on the desired stiffness, the elastic body 9 can be placed closer to or further away from joint piece 4 , or it can be completely omitted.
[0032] As shown, the facial muscle trainer according to the invention solves the problems of the state of the art by being manufactured as a one piece apparatus, so that the metal spring which was up to date necessary for stiffening can be omitted. An assembling is not necessary any more, and by means of the insert molding around the ribs as well as the coated bite surfaces, the facial muscle trainer is safe in terms of handling.
LIST OF REFERENCES
[0033] 1 facial muscle trainer
[0034] 2 leg
[0035] 3 leg
[0036] 4 joint piece
[0037] 5 bite surface
[0038] 6 bite surface
[0039] 7 rib
[0040] 8 elastic body
[0041] 9 mounting
[0042] 10 raised structures
[0043] 11 foots | A facial muscle trainer for training the facial muscles of a person, having a C-shaped clamp with two legs, which are joined by a joint piece, as well as two bite surfaces being arranged at the ends of the legs, characterized in that the facial muscle trainer has at least one rib at at least one of the two legs running along the longitudinal direction of the leg, increasing the stiffness of the leg. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the benefit of co-pending U.S. provisional application no, 61/977,063, filed on Apr. 8, 2014, the entire disclosure of which is incorporated by reference as if set forth in its entirety herein.
FIELD
[0002] The invention relates to fluid handling modules, and specifically to fluid handling modules for a biomedical instrument.
BACKGROUND
[0003] Conventional fluid handling for a biomedical instrument uses pumps, vessels, valves, regulators, connectors, tubing, and other components. These conventionally exist as discrete items in an instrument, so that a larger mass and volume is required.
[0004] For a compact biomedical instrument, it is highly desired that the fluid handling system be compact and miniaturized. Component selection should be judicious to minimize mass, volume, and power. In this manner, the fluidics module should encompass as many functions as possible to ensure maximal capability for the smallest footprint.
[0005] Having discrete components is an impediment to the development of compact biomedical instrumentation. Groups developing compact biomedical instrumentation have previously attempted to integrate a subset of these components. In these partially integrated approaches, the fluidics are still bulky and exist in large part as discrete components.
[0006] Microfluidics is an approach for removing the requirement for having significant amounts of tubing. While this is the case, microfluidics typically does not address mechanical components such as pressure regulators, solenoid valves, check valves, and pumps. These approaches typically still require conventional mechanical fluidic components that remain discrete.
[0007] While microfluidic integration is important to the field, generally, the greater the level of integration, the more complex and challenging the manufacturing. Furthermore, microfluidics is not as robust when it comes to areas where there are conventional mechanical components, such as pressure regulation and pumping.
[0008] In tight of the foregoing, it is desirable to have an improved fluidic manifold to reduce mass, volume, and power required.
SUMMARY
[0009] Embodiments of the invention concern a fluidics module that is appropriate for a small benchtop biomedical analyzer. The invention utilizes a judicious selection of off-the-shelf components with a microfluidics manifold. This approach minimizes manufacturing cost and increases robustness while maintaining the advantages of small mass and volume.
[0010] In one aspect, embodiments of the present invention relate to a fluid handling system. The fluid handling system includes a microfluidics manifold and at least one of a connector and a mating area integrated into the manifold to facilitate the connection of a discrete component to the manifold.
[0011] In one embodiment, the system further comprises a discrete component connected to the manifold. The discrete component may be selected from the group consisting of a miniature valve, a pump, a pressure regulator, a tubing connector, and an air connector.
[0012] In one embodiment, the microfluidics manifold includes a three-dimensional spatial network of microfluidic channels. In one embodiment, the system includes a mating area and the mating area is selected from the group consisting of a threaded recess, an inlet, an outlet, a threaded hole, and a mounting hole. In one embodiment, the mating area is one of an inlet and an outlet, and the system further comprises screw holes for connecting the discrete component to the manifold.
[0013] In one embodiment, the system comprises a connector selected from the group consisting of a screw and a gasket. In one embodiment, the system comprises a bypassable flow restrictor connected to the microfluidics manifold. In one embodiment, the system further includes at least one check valve connected to the microfluidics manifold.
[0014] In another aspect, embodiments of the present invention relate to a method for conducting a fluid analysis utilizing a microfluidics manifold connected to a sample source. The method includes providing pressurized air to the manifold; directing, via the manifold, the pressurized air to at least one vial connected to the manifold; and receiving materials from the at least one pressurized vial via a valve mounted on the manifold, wherein the microfluidics manifold compresses a three-dimensional spatial network of microfluidic channels.
[0015] In one embodiment, the pressurized air provided to the manifold is received at a regulator. In one embodiment, the method further includes connecting at least one vial to the manifold. In one embodiment, the method further includes providing a pressurized cleaning fluid to the manifold.
[0016] In yet another aspect, embodiments of the present invention relate to a fluid handling system. The fluid handling system includes a microfluidics manifold; a discrete pump connected to the manifold, providing pressurized air to the manifold; and at least one vial connected to the manifold, wherein the microfluidics manifold comprises a three-dimensional spatial network of microfluidic channels.
[0017] In one embodiment, the fluid handling system further includes a regulator connected to the manifold, the regulator receiving pressurized air from the pump and providing a uniform air flow with steady pressure. In one embodiment, the at least one vial is connected to the manifold by a valve. The valve may be, e.g., a solenoid valve or a latching valve. In one embodiment, the system comprises three vials connected to the manifold: a sample vial, a cleaning vial, and a vial for waste. In one embodiment, the system further includes a bypassable flow restrictor connected to the manifold. In one embodiment, the system further includes at least one check valve connected to the manifold.
[0018] The foregoing and other features and advantages of the present invention will be made more apparent from the descriptions, drawings, and claims that follow. One of ordinary skill in the art, based on this disclosure, would understand that other aspects and advantages of the present invention exist.
BRIEF DESCRIPTION OF DRAWINGS
[0019] FIG. 1 shows a block diagram schematic of one exemplary embodiment of the fluidics system in accord with the present invention;
[0020] FIG. 2 shows the overall system valving schematic for the embodiment of FIG. 1 with flow restrictors, check valves, and solenoid valves;
[0021] FIG. 3 shows the front view of one non-limiting embodiment of a fluidics module comprising the manifold, valves, tubing connectors, and regulator.
[0022] FIG. 4 shows the side view of the exemplary fluidics module of FIG. 3 including the manifold, regulator, air inlet, and pump.
[0023] FIG. 5 shows the back view of the exemplary fluidics module of FIG. 3 comprising the manifold, air connectors, pump, tubing connectors, and valves.
[0024] FIG. 6 shows an isometric view of the exemplary fluidics module of FIG. 3 with the manifold, valves, tubing connectors, regulator, and pump.
[0025] FIG. 7 shows the bottom view of the exemplary fluidics module of FIG. 3 showing mounting holes to the biomedical instrument.
[0026] FIG. 8 shows a 3D CAD front view of the exemplary fluidics module of FIG. 3 , illustrating the channels within the manifold.
[0027] FIG. 9 shows a 3D CAD back view of the exemplary fluidics module of FIG. 3 , illustrating the channels within the manifold.
[0028] In the drawings, like reference characters generally refer to corresponding parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed on the principles and concepts of operation.
DETAILED DESCRIPTION
[0029] In embodiments of the present invention, tubing and connectors are minimized and the majority of the fluidic components are somehow attached to a fluidics manifold, thus minimizing fluidic connections or tubing length. In one embodiment, the fluidics module utilizes microfluidic means of removing the requirement for significant networks of tubing, Mechanical components, such as off-the-shelf pumps and regulators, can be directly mounted to the manifold to eliminate or minimize connections between the components. Furthermore, judicious use of existing mechanical components such as valves and regulators allows for ease of manufacturing and robustness while maintaining a small footprint.
[0030] In one embodiment, the core of the fluidics module is a microfluidics manifold that has a 3D spatial network of microfluidic channels. This 3D spatial arrangement minimizes tubing and interconnects. The advantage of the 3D network is that junctions, intersections, and tubing management are contained within the manifold. The use of this type of manifold increases the level of tubing organization, utilizes a single manifold, and his into a compact space. The fluidics manifold has various connectors and mating areas for conventional mechanical components. There is a threaded recess for a pressure regulator. There are inlets and outlets for low power valves and also connecting screw holes that allow the valves to the mounted. There are threaded screw holes for leak-proof tubing connectors that lead to other parts of the instrument, including sample and waste vials. There is a mounting hole for the diaphragm pump. The shape of the module is compact and follows the form of the biomedical instrument. There are also screw mounting holes for manifold to the instrument.
[0031] Mating of components to the module is facile. The manifold has various threaded holes or threaded inserts that accept mechanical components. For instance, the valves are secured by screws. Gaskets on the valves mate to the manifold. The screws press the valve against the surface of the manifold. The holes on the valve mate with those on the manifold to allow passage of fluid from the inlet to the outlet of the valve. A series of valves are located on the manifold. The pressure regulator is a screw-in type pressure regulator. An O-ring type seal is formed between the pressure regulator and the manifold. Tubing connectors are also screw-in type to ensure robust seals. Air connectors take in pump air or deliver the regulated and unregulated air to pressure sensors on an electronics board. The system allows for priming, cleaning, and sample analysis modes.
[0032] Other parts of the fluidic system include the sample vials, flow cell, sample loader, and burp line for a flow cytometer instrument. The sample vials contain sheath fluid, cleaning fluid, and waste. The flow cell assembly has four ports: sample inlet, sheath, and burp port, and waste. Tubing connects the fluidics module to the sample loader, which in turn is connected to the inlet of the flow cell. Pressure and fluid attached to the burp tine allows for bubble removal and priming. A series of check valves in the system prevent backwards movement of fluid. Overall, the greater fluidic system relies on the simplicity of the fluidics module to manage its interactions. The fluidics module is thus the hub of the fluidics system.
[0033] The invention therefore bypasses the limitations of conventional technologies in that it provides fluidic integration and manufacturability. This is in contrast to existing microfluidic integration approaches which have high manufacturing complexity. This invention's hybrid approach allows for utilization of off-the-shelf valves, regulators, connectors, and pumps to maximize simplicity of the fluidics. The end result is a compact fluidics module and system appropriate for a commercial, compact biomedical analyzer.
[0034] In one embodiment, the fluidics module is fabricated by 3D printing using a clear, translucent plastic such Watershed XC 11122, which is translucent and water resistant. The screw holes are manually tapped to allow for tubing connectors (IDEX, Mass.). Miniature valves are utilized for actuation (The Lee Company, Conn.). The pressure regulator and pump are commercial off-the-shelf components. The pump is a conventional diaphragm air pump that operates between 0-15 psi. 1/16″ OD, 0.020″ ID FEB tubing is utilized to connect the vials to air and to the ports on the manifold. Flexible tygon tubing is utilized to connect the air pump to the manifold and the pressure sensors to the manifold. Flow restrictor tubing is 1/16″ OD, but with smaller ID, as low as 0,003″ ID. Commercially-available check valves are utilized in the system to prevent backflow.
[0035] The manifold receives air from the air pump. Once the air is in the manifold, the unregulated air is directed towards a pressure sensor and to the regulator. The regulator stabilizes the air flow to produce a uniform and steady pressure output. The regulated air is also measured by a pressure sensor. Regulated air is directed towards two fluid vials, a sheath and a cleaner vial. This pressurizes the vials. Flow from these vials is controlled by solenoid valves that are located on the manifold. These valves are directly mounted onto the manifold assembly. Opening of various valves allow for movement of the sample and flow focusing in the system. The sample loader, sheath, and waste need to be opened in order for the sample to be flow focused in a cytometer biomedical instrument. The flow restrictor creates a differential flow rate between the sample and the sheath, allowing the sample to be focused down to a small, thin stream, suitable for cytometry measurements. The channels in the manifold are 0.020″ wide. The flow restrictor can be bypassed with the right combination of the valving, allowing the sample to move to the flow cell in a much more rapid manner. The sample line can be cleaned utilizing the cleaning fluid and appropriate actuation of the right sequence of the valves.
[0036] The fluidics module is designed for use in a portable cytometer where there is limited volume and thus fluidic integration is paramount. The fluidics module is attached to a flow cell assembly that has a sample input, burp line input, sheath fluid input, and a waste port. The sample line is driven by the sheath fluid. The waste goes through the manifold, to a valve, and then to a waste vial. The burp line is directly connected to the flow cell assembly. The burp line is utilized to clear any bubbles from the system. The sample loader allows a small sample (5-10 μL) to be loaded in-line with the rest of the system. Various check valves are strategically located throughout the fluidics system so that flushing through the burp lines allows for high pressure flushing. Check valves can prevent backflow at higher pressures than solenoid valves. Overall, the fluidics module is at the core of the larger fluidics system.
[0037] FIG. 1 shows a block diagram schematic of one exemplary embodiment of the fluidics system. The dotted line represents the manifold 100 . Five valves are labeled I-V. Air ports are labeled 6 - 8 . Connector ports are labeled 1 - 5 . “Reg” stands for regulator; “unreg” stands for unregulated air. A-E represents the connections to the vials. One of ordinary skill would understand that the number of ports and their configuration will necessarily vary from embodiment to embodiment, and thus this example is in no way intended to limit the scope of the invention.
[0038] FIG. 2 shows the overall system valving schematic for the embodiment of FIG. 1 with flow restrictors, check valves, and solenoid valves;
[0039] FIG. 3 shows the front view of one non-limiting embodiment of a fluidics module comprising the manifold, valves, tubing connectors, and regulator.
[0040] FIG. 4 shows the side view of the exemplary fluidics module of FIG. 3 including the manifold, regulator, air inlet, and pump.
[0041] FIG. 5 shows the back view of the exemplary fluidics module of FIG. 3 including the manifold, air connectors, pump, tubing connectors, and valves.
[0042] FIG. 6 shows an isometric view of the exemplary fluidics module of FIG. 3 including the manifold, valves, tubing connectors, regulator, and pump.
[0043] FIG. 7 shows the bottom view of the exemplary fluidics module of FIG. 3 with mounting holes to the biomedical instrument.
[0044] FIG. 8 shows a 3D CAD front view of the exemplary fluidics module of FIG. 3 illustrating the channels within the manifold.
[0045] FIG. 9 shows a 3D CAD back view of the exemplary fluidics module of FIG. 3 illustrating the channels within the manifold.
[0046] In other embodiments, the shape and size of the fluidics module can vary. Furthermore, the number of valves, regulators, connectors, pumps, vials, and flow restrictors can also vary in type and number. The invention is designed to teach integration of multiple discrete mechanical fluidic components with a 3D network of channels for reducing the overall mass, volume, and power of any fluidic system in a biomedical instrument.
[0047] Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation and/or engineering, many equivalents to the specific embodiments of the invention described herein. The scope of the present invention is not intended to be limited to the above Description, but rather is as set forth in the claims that follow the reference list. | An integrated fluidics module that reduces mass and volume so that it can readily fit inside a compact biomedical instrument. A fluidics module that integrates discrete components (e.g., pump, connectors, tubing, regulator, and valves) reduces mass and volume requirements. | 1 |
BACKGROUND OF THE INVENTION
The present invention relates generally to a device for the treatment for hiccups, and more specifically, to a method and apparatus for the treatment of hiccups involving galvanic stimulation of the Superficial Phrenetic and Vagus nerves.
A Hiccup, also known as Hiccough, or Singultus, is an involuntary spasm of the diaphragm, resulting in an involuntary inhalation which is abruptly interrupted by the involuntary closing of the glottis, and resulting in the familiar and characteristic sound of a hiccup.
The exact anatomic and physiological mechanism responsible for causing hiccups remains unknown. Previous studies, such as “Hiccups,” by P. Rosseau, M.D., Southern Medical Journal, Vol., 88, Pp. 175–181, 1995, attributed the hiccup reflexive arc to afferent and efferent nerve branches that are centrally connected between cervical segments 3 and 5. This branch encompasses the phrenic and vagus nerve fibers among others. It is the reflexive discharge of the phrenic nerve that results in the spasmodic contraction of the diaphragm, and that produces a hiccup.
The Merck Manual, Section 3, Chapter 21, “Functional UpperGastrointestinal Complaints,” states that “Hiccups follow irritation of afferent or efferent nerves or of medullary centers that control the respiratory muscles, particularly the diaphragm. Afferent nerves may be stimulated by swallowing hot or irritating substances. High blood CO 2 irihibits hiccups; low CO 2 accentuates them. Hiccups are more common in men and often accompany diaphragmatic pleurisy, pneumonia, uremia, alcoholism, or abdominal surgery.”
Hiccups lasting up to 48 hours are classified as “bouts”. Hiccups lasting longer than 48 hours are called “persistent.” Those lasting longer than a month are called “intractable.”
Hiccups cures are ubiquitous and vary from the scientific to the absurd. Each “cure” achieves various levels of success based on individuals favorites, beliefs and anecdotal observations. Many simple cures involve increasing Pa CO2 and inhibiting diaphragmatic activity by a series of deep breath-holdings or by rebreathing deeply into a paper bag. Simple activities that involve Vagal nerve stimulation are often recommended and can include drinking a glass of water rapidly, swallowing dry bread or crushed ice, inducing vomiting, or applying traction on the tongue or pressure on the eyeballs. Carotid sinus compression (massage) may be tried or strong digital pressure may be applied over the phrenic nerves behind the sternoclavicular joints.
Other maneuvers at the disposal of medical practitioners in treating patients with persistent or intractable Hiccups include esophageal dilation with a small bougie, galvanic stimulation of the phrenic nerve, and gastric lavage. Drugs can also be employed to control persistent hiccups including scopolamine, amphetamine, prochlorperazine, chlorpromazine, phenobarbital, and narcotics. Metoclopramide appears to help some patients. Nevertheless, successful treatment with drugs is often elusive. In troubling, refractory cases, the phrenic nerve may be blocked by small amounts of 0.5% procaine solution, although this extreme remedy risks respiratory depression and pneumothorax.
U.S. Pat. No. 6,152,953 (2000) “Device for the treatment of Hiccups” employed a physiological cold block to the Phrenetic and Vagus nerves. The stated physiological conditions and implications with this prior Patent are similar to the instant case. However the means, methods and apparatus are entirely unique to this application. The present Invention is superior to this prior art because it does not require a cold source or the access to refrigeration equipment and electricity. The present invention also is faster acting in that it does not require the user to wear an appliance around their neck for an extended period of time. Rather the present invention can treat hiccups during the act of consumption of a potable liquid from the device and relief can be obtained quickly.
The aforementioned plurality of suggested treatments for the Hiccups indicates that no single, effective and reliable treatment exists. The present invention fulfills the need for a safe, simple and effective treatment and provides unique advantages over prior art.
BRIEF SUMMARY OF THE INVENTION
The object of the present invention is to galvanically stimulate the superficially coursing vagus and phrenic nerves in order to reliably interrupt the Hiccup Reflexive Arc. To achieve this object, the present invention provides a method and apparatus for the treatment of hiccups involving galvanic stimulation of the superficially coursing phrenic and vagus nerves utilizing an cup-like appliance designed for the containment and human consumption of a conductive potable liquid such as tap water. The present invention includes a first electrode of an electrically conductive material integrated into the body of the vessel, and a second electrode of electrically conductive material also integrated into the body of the vessel. The electrically conductive materials constituting the first and second electrodes have different electrochemical potentials. When the vessel is filled with an electrically conductive potable liquid, such as tap water, the electrodes are immersed in said liquid. Thus, an electric potential is developed by and between the electrodes. The second electrode is also configured as to make contact with the temple and cheek region of the face when drinking liquids from the cup-like vessel. During typical human oral consumption of the liquid from the lip of the cup-like vessel of the present invention, an electrical circuit is created and the electro-chemically produced potential energy, or Ions, are conducted through the electrodes and the electro-conductive liquid to the user's lips, mouth and throat as well as the temple region of the face, thus stimulating the superficially coursing vagus and phrenic nerves and reliably interrupting the Hiccup Reflexive Arc.
According to the unique features of the present invention, the preferred embodiment is a cup-like vessel that is constructed of a carbon based metal with a specific electrochemical potential which serves as the first electrode. The second electrode is a copper alloy material which has a dissimilar electrochemical property than the carbon based metal of the vessel body. The first electrode is electrically insulated from the second electrode except when the vessel is filled with an electrically conductive liquid such as tap water. During use, significant surface area of both electrodes are in contact with the liquid. One electrode is in contact with the lips and mouth, and the second electrode is in contact with the temple or cheek region of the face. Thus a flow of Ions is created by the electrochemical potentials of the dissimilar metal electrodes and is conducted through the body tissues sufficiently to interrupt the Hiccup Reflexive Arc.
In another embodiment of the invention, the vessel is constructed of any suitable non-conductive materials such as plastic, and the electrodes are formed of electrically conductive materials in the shape of segments of the vessel, which are integrated into the insulative plastic material. In yet another embodiment, the electrodes are applied to an existing drinking vessel constructed of any material. The detailed description of the drawings will further explain the objects and advantages of the present invention
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of the device for the treatment of hiccups embodying the preferred practice of the present invention.
FIG. 2 is a side elevation view of the device of FIG. 1 as seen substantially from a plane indicated by a line 2 — 2 in FIG. 1 .
FIG. 3 is a top plan view of the appliance in FIG. 1 .
FIG. 3 is a top plan view of the device in FIG. 1 .
FIG. 4 is a sectional view as seen from a plane indicated by a line 4 - 4 in FIG. 2 & FIG. 3
FIG. 5 is a schematic front view illustrating the device of FIG. 1 during use.
FIG. 6 is a schematic side view illustrating the device of FIG. 1 during use.
DETAILED DESCRIPTION OF THE INVENTION
Referring first to FIG. 1 , the Device for the Treatment of Hiccups of the present invention includes a cup like vessel designed for the containment and consumption of potable liquids 1 , which also serves as the first electrode, and a second electrode 2 , which is supported by a bracket 4 . The second electrode 2 is electrically insulated from the bracket 4 and the first electrode 1 by a non-conductive insulator 5 . As shown in FIGS. 2 & 3 . the support bracket 4 is of similar dimension to second electrode 2 with connecting insulators 5 creating a gap between them. The second electrode 2 is configured as to make contact with the user's skin in the region of the face and temple 8 as can be seen in FIGS. 5 & 6 . The configuration of the second electrode 2 can be best seen in the cross-sectional view of FIG. 4 , which illustrates how the second electrode 2 is immersed in a conductive liquid 3 during the act of drinking from the lip 2 of the user and then extends a distance above the rim 6 of the vessel 1 and is configured at an optimal angle A to make contact with the skin in the temple and cheek region 8 of the head.
REFERENCES CITED
U.S. Patent Documents
5861022
January 1999
Hipskind
607/109.
OTHER REFERENCES
Lewis, James H., M.D., “Hiccups: Causes and Cures,” Journal of Clinical Gastroenterology, vol. 7(6), December 1985, pp. 539–552.
Noble, E. Clark, “Hiccup,” The Canadian Medical Association Journal, July 1934, pp. 38–41.
Travell, Janet G., M.D., “A Trigger Point for Hiccup ,” The Journal of the American Osteopathic Association, vol. 77, December 1977, pp. 308–312.
Rousseau, Paul, M.D., “Hiccups,” Southern Medical Journal, vol. 88, No. 2, February 1995, pp. 175–181.
Launois, S., et al., “Hiccup in Adults: An Overview,” European Respiratory Journal, vol. 6, No. 4, April 1993, pp. 563–575.
Hulbert, N. G., M.D., “Hiccoughing,” The Practitioner, vol. 167., September 1951, pp. 286–289. | A device for the treatment of hiccups, and more specifically, to a method and apparatus for the treatment of hiccups involving galvanic stimulation of the Superficial Phrenetic and Vagus nerves using an electric current. | 0 |
RELATED APPLICATIONS
[0001] This application claims priority to Taiwan Application Serial Number 102123840, filed Jul. 3, 2013, which is herein incorporated by reference.
BACKGROUND
[0002] 1. Field of Invention
[0003] The present invention relates to a method of preparing silver particles. More particularly, the present invention relates to a method of preparing silver particles and core-shell silver particles, and the formed core-shell silver particles.
[0004] 2. Description of Related Art
[0005] In the recent years, the core-shell and hollow silver particles have received much attention for their excellent natures and wide applicability such as conductors, electrical contacts and wound dressing. For example, the wound dressing of antibiosis and silver conductive adhesive are the major commercialized applications of the silver particles. However, the major processes of making silver particle, like reduction process and sol-gel process, are both conducted in batch and thus have less potential for mass production in view of business.
[0006] At present, most of the applications use solid silver particle, which has some issues for further improvement. For example, the solid silver particle most likely is not totally consumed after the wound dressing of antibiosis expires, which is not economic and wasting. On the other hand, the solid silver particles may sediment after a period of time of idle due to large difference of evident density between the solid silver particles and the gel solution, which makes uneven distribution of the particles in gel solution and deteriorates the properties of the product.
[0007] Concerning the silver particles with hollow structure, the major measures of preparing the hollow structure includes soft template, hard template, and Kirkendall effect. The soft template needs additional heating process step to remove polymer template and may involve carbon contamination problem. The hard template needs to use acid/base to remove the template, causing environmental pollution and need to deal with the post-treatment of acid/base. Kirkendall effect also has defects due to its complex procedures and high instrument cost.
SUMMARY
[0008] Therefore, the present disclosure provides a method of preparing hollow and core-shell silver particle in a continuous process, which can provide silver particles in a mass production way for the industry and choose using glycine nitrate method as the hollow formation mechanism for the silver particles. The glycine nitrate can be removed easily during the heating process due to its low molecular weight, so as to improve the defects in prior art. The prepared core-shell and hollow silver particles can replace the solid silver particles using on the market now to improve the efficiency of silver particle.
[0009] One aspect of the present disclosure is a method for preparing core-shell and hollow silver particles includes mixing a silver salt with a glycine nitrate or starch as a solute in a polar solvent to form a precursor solution, in which the mole percentage of the silver salt over the silver salts plus glycine nitrate or starch is 5-50 mol % and the silver salt plus glycine nitrate or starch are 0.01-10 wt % to the precursor solution, atomizing the precursor solution to form a plurality of precursor droplets, and heating the precursor droplets to pyrolyze the precursor droplets and to form core-shell silver particles and hollow silver particles.
[0010] In various embodiments of the present disclosure, the silver salt is silver nitrate or silver acetate.
[0011] In various embodiments of the present disclosure, the polar solvent is water.
[0012] In various embodiments of the present disclosure, the solute weight percentage concentration of the precursor solution is 1 wt %.
[0013] In various embodiments of the present disclosure, the mole percentage of the silver salts over the silver salts plus glycine nitrate or starch of the precursor solution is between 12.5-50 mol %, the formed silver particles are the core-shell silver particles.
[0014] In various embodiments of the present disclosure, the mole percentage of the silver salts over the silver salts plus glycine nitrate or starch of the precursor solution is less than 12.5 mol %, the formed silver particles are the hollow silver particles.
[0015] In various embodiments of the present disclosure, the step of heating the precursor droplets to pyrolyze the precursor further includes evaporating the polar solvent of the precursor droplets, precipitating the solute of the precursor droplets, and pyrolyzing the solute.
[0016] Another aspect of the present disclosure provides a core-shell silver particle includes a silver core, a silver shell, encapsulating the silver core, and a hollow structure, between the silver core and the silver shell.
[0017] In various embodiments of the present disclosure, the diameter of the core-shell silver particle is about 100-1,000 nanometers.
[0018] It is to be understood that both the foregoing general description and the following detailed description are by examples, and are intended to provide further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The invention can be more fully understood by reading the following detailed description of the embodiment, with reference made to the accompanying drawings as follows:
[0020] FIG. 1 is a flowchart of a method preparing hollow and core-shell silver particles according to various embodiments of the present disclosure;
[0021] FIG. 2 is a schematic diagram of an apparatus for preparing hollow and core-shell silver particles according to various embodiments of the present disclosure;
[0022] FIGS. 3A-3B are Thermogravimetric analysis graph of silver nitrate and glycine nitrate according to various embodiments of the present disclosure;
[0023] FIGS. 4A-4D are transmission electron microscopy (TEM) images of silver particles prepared in comparison 1 and experiments 1-3 according to various embodiments of the present disclosure;
[0024] FIGS. 5A-5C are TEM images of silver particles prepared in comparison 2 and experiments 4-5 according to various embodiments of the present disclosure;
[0025] FIG. 6 is a TEM image of silver particles prepared in experiment 6 according to various embodiments of the present disclosure; and
[0026] FIG. 7 is a sectional view of the core-shell silver particle according to various embodiments of the present disclosure.
DETAILED DESCRIPTION
[0027] Reference will now be made in detail to the present embodiments of the disclosure, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts.
[0028] One aspect of the present disclosure is a method for preparing core-shell and hollow silver particles includes the following steps. Referring to FIG. 1 , step 100 is mixing a silver salt with a glycine nitrate or starch as a solute in a polar solvent to form a precursor solution, in which the mole percentage of the silver salt over the silver salts plus glycine nitrate or starch is 5-50 mol % and the silver salt plus glycine nitrate or starch are 0.01-10 wt % to the precursor solution. some embodiments of the present disclosure, the silver salt is silver nitrate or silver acetate. In various embodiments of the present disclosure, the polar solvent is water. In various embodiments of the present disclosure, the mole percentage of the silver salts over the silver salts plus glycine nitrate or starch of the precursor solution is between 12.5-50 mol %, the prepared silver particles have a core-shell structure. In various embodiments of the present disclosure, the mole percentage of the silver salts over the silver salts plus glycine nitrate or starch of the precursor solution is less than 12.5 mol %, the prepared silver particles have a hollow structure. In various embodiments of the present disclosure, the mole percentage of the silver salts over the silver salts plus starch of the precursor solution is about 50 mol %, the manufactured silver particles have a hollow structure.
[0029] Step 110 is atomizing the precursor solution to form a plurality of precursor droplets. In various embodiments of the present disclosure, using an ultrasonic humidifier to atomize the precursor solution, where the ultrasonic frequency is 1.65 MHz when the polar solvent is water. In various embodiments of the present disclosure, the diameter of the precursor droplets is about 3-20 μm, the diameter of the precursor droplets has positive correlation with the precursor concentration. The preferable concentration range for atomizing the solution is the silver salt plus glycine nitrate or starch is 0.01-10 wt % to the precursor solution.
[0030] Step 120 is heating the precursor droplets to pyrolyze the precursor droplets to form the core-shell silver particles and the hollow silver particles. Other parts of the precursor droplets are pyrolyzed to gas. In various embodiments of the present disclosure, the heating apparatus is a temperature controllable tube furnace, which can control the temperature in the tube to three sections: preheating section (200-400° C.), calcining section (500-800° C.), and cooling section (300-500° C.). In various embodiments of the present disclosure, the heating step includes evaporating the polar solvent of the precursor droplets, precipitating the solute of the precursor droplets, and pyrolyzing the solute.
[0031] FIG. 2 is a schematic diagram of an apparatus for preparing hollow and core-shell silver particles according to various embodiments of the present disclosure. But the method in the present disclosure is not limit to prepare by the apparatus only. As illustrated in FIG. 2 , a precursor solution 210 is added to an ultrasonic humidifier 220 , the precursor solution 210 is atomizing to form the precursor droplets. The precursor droplets first enter a quartz tube 230 than enter a tube furnace 240 . The precursor droplets are pyrolyzed to form silver particles and gas in the tube furnace 240 . In some embodiments of the present disclosure, using an electrostatic deposition collector 250 with a discharge equipment 260 to collect the silver particles. The gas formed after pryolysis in the tube furnace 240 is passing through cooling water 270 and a filter 280 , than exhaust by a pump 290 .
[0032] FIGS. 3A-3B are Thermogravimetric analysis graph of silver nitrate and glycine nitrate according to various embodiments of the present disclosure. Referring to FIG. 3A , the graph shows that silver nitrate has two stages of pyrolysis. The first stage is the temperature rise from room temperature to 442° C., in which the specimen losing 5% weight, estimating that the silver nitrate decomposed to silver nitrite in this stage. The second stage is the temperature rise from 442° C. to 700° C., in which the weight of the specimen is lost from 95% to 67%, estimating that the silver nitrite is pyrolyzed to silver only. Referring to FIG. 3B , the graph shows that glycine nitrate has two stages of pyrolysis. The first stage is the temperature rise from room temperature to 260° C., in which the specimen losing 51% weight. The second stage is the temperature rise over 650° C., the glycine nitrate is totally pyrolyzed, no weight left. Therefore to decide the pyrolysis temperature is at least 700° C.
[0033] Following are some embodiments to further elaborate the method of the present disclosure, but only for explanation, should not be limited to the description of the embodiments contained herein. The scope of protection for present disclosure depends on the following claims.
Embodiments
[0034] A. Preparing the silver particles with the precursor solution prepared from different ratio of silver nitrate and glycine nitrate.
[0035] Comparison 1: No Glycine Nitrate in the Precursor Solution
[0036] Preparing 1 wt % silver nitrate in water as the precursor solution, the experiment apparatus is as illustrated in FIG. 2 . The precursor solution 210 is added to an ultrasonic humidifier 220 , the precursor solution 210 is atomizing to form the precursor droplets. The precursor droplets first enter a quartz tube 230 than enter a tube furnace 240 , passing through the preheating section (200-400° C.) calcining section (500-800° C.), and cooling section (300-500° C.) The precursor droplets are pyrolyzed to form silver particles and gas in the tube furnace 240 . Using an electrostatic deposition collector 250 with a discharge equipment 260 to collect the silver particles. The gas formed after pryolysis in the tube furnace 240 is passing through cooling water 270 and a filter 280 , than exhaust by a pump 290 . The silver particles formed by this method have solid structure.
[0037] Referring to FIG. 4A , FIG. 4A is a TEM image of silver particles prepared in comparison 1 according to various embodiments of the present disclosure. The dark parts in the image represent to solid silver particles. The particle diameter is about 360 to 1120 nanometer.
[0038] Experiment 1: the mole percentage of the silver nitrate over the silver nitrate plus glycine nitrate is 25 mol % in the precursor solution
[0039] Preparing 1 wt % precursor solution, in which the mole percentage of the silver nitrate over the silver nitrate plus glycine nitrate is 25 mol %. The experiment process is the same as comparison 1.
[0040] Referring to FIG. 4B , FIG. 4B is a TEM image of silver particles prepared in experiment 1 according to various embodiments of the present disclosure. The core-shell silver particles are shown in the image, including the core and shell structure as the dark portion and the hollow structure as the brighter portion between the core and shell in the image. The particle diameter is about 118 to 216 nanometers, and the porosity is 22.6%.
[0041] Experiment 2: the mole percentage of the silver nitrate over the silver nitrate plus glycine nitrate is 14.2 mol % in the precursor solution
[0042] Preparing 1 wt % precursor solution, in which the mole percentage of the silver nitrate over the silver nitrate plus glycine nitrate is 14.2 mol %. The experiment process is the same as comparison 1.
[0043] Referring to FIG. 4C , FIG. 4C is a TEM image of silver particles prepared in experiment 2 according to various embodiments of the present disclosure. The core-shell silver particles are shown in the image, including the core and shell structure as the dark portion and the hollow structure as the brighter portion between the core and shell in the image. The particle diameter is about 127 to 195 nanometers, and the porosity is 27.2%.
[0044] Experiment 3: the mole percentage of the silver nitrate over the silver nitrate plus glycine nitrate is 12.5 mol % in the precursor solution
[0045] Preparing 1 wt % of precursor solution, in which the mole percentage of the silver nitrate over the silver nitrate plus glycine nitrate is 12.5 mol %. The experiment process is the same as comparison 1.
[0046] Referring to FIG. 4D , FIG. 4D is a TEM image of silver particles manufactured in experiment 3 according to various embodiments of the present disclosure. The hollow silver particles are shown in the image, including the shell structure as the dark portion and the hollow structure as the brighter part inside the shell in the image. The particle diameter is about 143 to 235 nanometers, and the porosity is 36.5%.
[0047] B. Preparing the silver particles with the precursor solution prepared from different ratio of silver acetate and glycine nitrate.
[0048] Comparison 2: No Glycine Nitrate in the Precursor Solution
[0049] The experiment process is the same as comparison 1, but to change the precursor solution including 1 wt % silver nitrate to 1 wt % silver acetate.
[0050] Referring to FIG. 5A , it is a TEM image of silver particles prepared in comparison 2 according to various embodiments of the present disclosure. The image shows that the silver particles prepared in comparison 2 have solid is structures.
[0051] Experiment 4: the mole percentage of the silver acetate over the silver acetate plus glycine nitrate is 25 mol % in the precursor solution
[0052] The experiment process is the same as comparison 1, but to change the precursor solution to 1 wt % silver acetate and glycine nitrate mixture solution, in which the mole percentage of the silver acetate over the silver acetate plus glycine nitrate is 25 mol %.
[0053] Referring to FIG. 5B , FIG. 5B is a TEM image of silver particles prepared in experiment 4 according to various embodiments of the present disclosure. The core-shell silver particles are shown in the image, including the core and shell structure as the dark portion and the hollow structure as the brighter portion between the core and shell in the image. The porosity is 36.5%.
[0054] Experiment 5: the mole percentage of the silver acetate over the silver acetate plus glycine nitrate is 16.7 mol % in the precursor solution
[0055] The experiment process is the same as comparison 1, but to change the precursor solution to 1 wt % silver acetate and glycine nitrate mixture solution, in which the mole percentage of the silver acetate over the silver acetate plus glycine nitrate is 16.7 mol %.
[0056] Referring to FIG. 5C , FIG. 5C is a TEM image of silver particles prepared in experiment 5 according to various embodiments of the present disclosure. The core-shell silver particles are shown in the image, including the core and shell structure as the dark portion and the hollow structure as the brighter portion between the core and shell in the image. The porosity is 33.81%.
[0057] C. Preparing the silver particles with the precursor solution prepared from silver nitrate and starch.
[0058] Experiment 6: the mole percentage of the silver nitrate over the silver nitrate plus starch is 50 mol % in the solution
[0059] The experiment process is the same as comparison 1, but to change the precursor solution to 1 wt % silver nitrate and starch mixture solution, in which the mole percentage of the silver nitrate over the sliver nitrate plus starch is 50 mol %.
[0060] Referring to FIG. 6 , FIG. 6 is a TEM image of silver particles prepared in experiment 6 according to various embodiments of the present disclosure. The hollow silver particles are shown in the image, including the shell structure as the dark portion and the hollow structure as the brighter portion inside the shell in the image.
[0061] Referring to FIG. 7 , FIG. 7 is a sectional view of the core-shell silver particle according to various embodiments of the present disclosure. The core-shell silver particle includes a silver core, a silver shell, which encapsulating the silver core, and a hollow structure, which is between the silver core and the silver shell. In various embodiments of the present disclosure, the diameter of the core-shell silver particle is about 100-1000 nanometer.
[0062] The present disclosure provides the method of continuously preparing the core-shell and hollow silver particles. The method not only is a continuous process that can apply in industry mass production, but also can control porosity of silver particles that can apply in the commercialized silver particle products to save the amount of silver using and the cost. Also the porosity of the silver particles can be controlled depend on the using time of the products to maximize the utility.
[0063] For example, the wound dressing of antibiosis sometimes needs to be thrown away due to reach their expiration date, but there may still have some non-reacted silver inside the silver particles. So the porosity controllable silver particle provided in the present disclosure can adjust the silver amount in the silver particle base on the expiration date to minimize the silver waste.
[0064] In silver conductive adhesive, the solid silver particles may sediment after a period of time of idle due to large difference of evident density between the solid silver particles and the gel solution, which makes uneven distribution of the particles in gel solution and deteriorates the properties of the product. Hollow silver particles, because of having air inside the particles, can evidently decrease the density of the silver particles to minimize the density difference between the solid silver particles and the gel solution to decrease the sedimentation.
[0065] Although the present invention has been described in considerable detail with reference to certain embodiments thereof, other embodiments are possible. Therefore, the spirit and scope of the appended claims should not be limited to the description of the embodiments contained herein.
[0000] It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present invention without departing from the scope or spirit of the disclosure. In view of the foregoing, it is intended that the present disclosure cover modifications and variations of this disclosure provided they fall within the scope of the following claims. | A method for preparing core-shell and hollow silver particles is provided. In the method silver salts and glycine nitrate or starch are mixed with solvent to form precursor solution. The mole percentage of the silver salts over the silver salts plus glycine nitrate or starch is 5 to 50 mol %. The precursor solution is then atomized to form precursor droplets. The precursor droplets are heated by pyrolysis to form silver particles. The composition of the precursor solution can be adjusted to finely manipulate the structure of the silver particles. | 1 |
BACKGROUND OF THE INVENTION
The present invention relates to a heat exchange panel and more particularly to a solar heat exchange panel for use in heating fluids such as water in a swimming pool, and to the method of fabricating such a panel.
Solar heating panels for swimming pools are well known. In the past a panel or series of panels has been constructed having an inlet connected to a pump for delivery of water to the panels and an outlet for delivery of water from the panels back to the pool. These panels have used relatively large cross section straight-through or serpentine passage arrangements. The flow path through the panels and the inlet and outlet piping has been subject to leaks due to faults in the many mechanical joints and fittings. Moreover, the complexity of previously available panel assemblies and the low efficiency of heat transfer to the water flow due to the large cross section passages rendered previous solar heaters unattractive. There is, therefore, a need for simple, lightweight, efficient, structurally sound solar heat exchange panel, and for a simple process for fabricating the same.
SUMMARY AND OBJECTS OF THE INVENTION
The solar heating panel disclosed herein is a relatively thin flat sheet having multiple tubular passages running lengthwise therethrough. The panels are cut to a predetermined length and spaced flanges are formed on the panel ends on either side of the tubular passage ends using heated dies. A pair of hollow headers are cut having a length comparable to the width of the panel, and having apertures through one side. The material of the headers and the spaced flanges is heated to the melting point and the headers and flanges are forced together under pressure creating a unitary assembly having a watertight weld between the headers and the panels when the material solidifies. Plenum chambers are formed between the panel ends and the headers. The apertures through the sides of the hollow headers extend into the plenum chambers. An unobstructed flow path is constructed extending from an inlet to one header, through the apertures, one plenum chamber, the tubular passages, the opposite plenum chamber, the apertures in the opposite header, and through the opposite header to an outlet.
In general, it is an object of the present invention to provide an efficient and inexpensive heat exchanger for swimming pools.
It is another object of the present invention to provide a solar heat exchange panel for raising the temperature of the water in a swimming pool.
It is another object of the present invention to provide a heat exchange panel which may be used to cool the water of a swimming pool when the environment is at a lower temperature than the pool water.
Another object of the present invention is to provide a solar heating panel which may be easily fabricated, using a minimum of process steps.
Another object of the present invention is to provide a solar heating panel in modular form which may be assembled into a solar heater which may contain any desired number of heater panel modules.
Additional objects of the present invention will become apparent by referring to the drawings and the description of the preferred embodiment.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is an isometric view of an assembled solar heat exchange panel.
FIG. 2 is a cutaway sectional view of an assembled solar heat exchange panel.
FIG. 3 is a sectional view along the line 3--3 of FIG. 2.
FIG. 4 is an isometric view of a panel prior to processing.
FIG. 4A is an isometric view of a panel cut to a predetermined length.
FIG. 4B is an isometric view of a heater panel undergoing the flange formation process.
FIG. 4C is a sectional view showing the cross-section of the heating die used in the bonding process.
FIG. 4D is an isometric view of a panel and a hollow header undergoing the bonding process.
FIG. 4E is an isometric view showing the unitary assembly resulting from the bonding process.
FIG. 5 is a detailed view of the area 5--5 of FIG. 4.
FIG. 6 is a partial plan view showing two unitary heat exchange assemblies joined.
FIG. 7 is a sectional view of another embodiment of panel and header assembly.
FIG. 8 is a partial plan view of another embodiment showing two unitary heat exchange assemblies joined.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The heat exchange panel provides a continuous flow path for a fluid, a portion of the flow path being utilized to exchange heat between the fluid and the panel environment. FIG. 1 shows a unitary heat exchange module 10 having spaced headers 11 and 12 disposed at opposite ends of a heat exchange panel 13.
In one embodiment, best seen in FIG. 2, headers 11 and 12 are hollow and have along one side a line of spaced holes 14. The holes 14 are countersunk as shown at 16 at the outer surface of headers 11 and 12. It should be noted in FIG. 2 that spaced holes 14 in header 11 are positioned in a staggered relationship relative to spaced holes 14 in header 12. Multiple tubular passages 17 extend lengthwise through panel 13 and are defined by the broad outside walls of panel 13 and a plurality of partitions 18 extending therebetween.
Each end of panel 13 is subjected to a forming process. In the embodiment of FIG. 2 spaced flanges 19 and 21 are formed as shown in FIG. 3. Plenum chambers 22 are defined between the ends of panels 13, the spaced flanges 19 and 21, and the outer surfaces of headers 11 and 12 when the headers are joined to panel 13. Identical plenum chambers 22 thus exist at opposite ends of panel 13 as seen in FIG. 2.
Heat exchange panels 13 are cut to shape and the ends are formed from the sheetlike member shown in FIG. 4 for the embodiment of FIG. 2 as follows. FIG. 4A shows the sheet like member cut to a predetermined length for a heat exchange panel 13. FIG. 4B shows the cut panel 13 with spaced flanges 19 and 21 respectively formed by pressing a heated knife edge die 23 into each end of panel 13. Knife edge die 23 is heated to a predetermined temperature, approximately 350°F for polyethylene panel material, and is pressed into the end of panel 13 at a predetermined rate. The panel material is heated to the plastic range by die 23 thereby allowing die 23 to form the flanges 19 and 21 by forcing apart the ends of panel 13 through which the tubular passages extend. The temperature and rate of advance of knife edge die 23 are important so that flanges 19 and 21 are formed while causing a predetermined reduction in cross section at the ends of tubular passages 17 without obstructing them completely. Heated die 23 may be advanced at a lower rate during the initial stages of forming and accelerated during the latter stages to assure that the channel ends are not fully closed. Once the spaced flanges 19 and 21 are formed, a coolant is injected about the die and the flanges as indicated by arrow 24 in FIG. 4B so that die 23 may be removed from contact with the end of panel 13 without altering the shape of flanges 19 and 21 as formed. The coolant solidifies the material of panel 13 prior to removal of the die 23.
The headers 11 and 12 are cut to a length which is approximately the width of panel 13. A line of spaced holes 14 having a countersink 16 is placed through the wall of headers 11 and 12. The holes 14 generally have a diameter which is in a ratio of 1:16 relative to the inside diameter of headers 11 and 12. By way of example, 1/8 inch diameter holes 14 are optimum for 2 inch diameter headers 11 and 12. The consideration is to obtain an optimum trade-off between head loss due to flow constriction and constant flow distribution throughout a plurality of panels 13.
A heated bonding die 26 for the embodiment of FIG. 2 has four projections 27 extending therefrom as best shown in FIG. 4C. Projections 27 each have a planar surface on their ends shown at 28, 29, 31, and 32 in FIG. 4C. Planar surfaces 28 and 31 are parallel and surfaces 29 and 32 are parallel.
Referring to FIG. 4D, heated bonding die 26 is positioned between panel 13 having flanges 19 and 21 formed thereon, and hollow header 12. Bonding die 26 is heated to the range of 450 to 600°F for the case when the material of panel 13 and header 12 is polyethylene. Planar surface 28 contacts the face of flange 19 and planar surface 29 contacts the face of flange 21. Surfaces 31 and 32 on die 26 contact the outside of hollow header 12 astraddle the line of holes 14. Panel 13 and header 12 are held in contact with heated die 26 until the surface material of the panel 13 and header 11 or 12 adjacent to the planar surfaces is melted. As soon as the surface material is melted, panel 13 and header 11 or 12 are drawn apart, die 26 is moved from between them, and the substantially parallel melted surfaces of panel 13 and header 11 or 12 are pressed together to form the unitary assembly 10, one end of which is shown in FIG. 4E. The material of panel 13 and headers 11 and 12 solidifies on cooling to form a fluid impervious bond.
The type of material used for the heat exchange panel 13 and upper and lower headers 11 and 12 will dictate to some extent the process used in fabricating the unitary assembly 10. There being no satisfactory bonding agents or solvents at the present time for polyethylene, heat forming and bonding methods are used. Use of other materials for the panel 13 and headers 11 and 12 or development of adhesives for bonding polyethylene may dictate the use of a particular adhesive or solvent for the bonding process. It is also advantageous to provide some ultraviolet inhibitor in the materials used in the fabrication of the solar heat exchange panel unitary assembly 10.
Unitary heat exchange assemblies 10 may be joined to produce a solar heat exchange array having as many unitary assemblies 10 as desired. As mentioned above, headers 11 and 12 are cut having a length approximately the same as the width of panel 13. The header lengths are cut longer than the panel widths when the method for joining unitary assemblies 10 shown in FIG. 6 is used. As may be seen in FIG. 6, when two unitary assemblies 10 are placed side-by-side the projecting ends of headers 11 and 12 are brought into butting position. A rubber collar 33 is placed around each header butt joint. Clamps 34 are placed around the outside of the collar 33 and tightened to preclude fluid leakage at the header butt joints.
The operation of the embodiment of unitary heat exchange assembly 10 having the configuration of FIG. 2 may now be described. Panels are placed in an environment from which a heat exchange is desired with a particular fluid. In the most common usage, solar heating panels are used to control the temperature of swimming pools. Generally it is desired to elevate the temperature of the water although occasions may arise when it is desirable to depress the temperature of the water. In either instance the unitary heat exchange assemblies 10 are fabricated and joined together using as many unitary assemblies 10 as desired. In general terms the total area of heat exchanger panels 13 should be a minimum of half the area of the swimming pool surface to achieve a reasonable efficiency level. When the application is that of heating the water in a swimming pool the panels may be oriented to generally receive the sun's rays orthogonally on the surface of panel 13. This is not a critical consideration since the heat absorption is related to the cosine function of the angle of incidence of the sun's rays on the surface of panel 13. The panel array may be set up on a roof top, in a field, or in any other convenient position accessible to direct sunlight.
Using the pool pump (not shown) water is pumped into an inlet end 36 shown in FIG. 2 on header 12. The opposite end of header 12 is either connected to additional unitary heat exchange assemblies 10 or is stopped by inserting a plug (not shown) therein. In the embodiment of FIG. 2 water flowing into header 12 passes radially through holes 14 into plenum chamber 22 adjacent to header 12. Header 12 is generally kept at a lower elevation than header 11 whereby the water rises in all of the tubular passages 17 at approximately the same rate until it reaches plenum chamber 22 adjacent upper header 11. The water passes radially through holes 14 into the interior of header 11 flowing therethrough until it exits through one end 37 of header 11 as seen in FIG. 2 whereupon it is directed to return to the pool.
Countersink 16 is placed in holes 14 in this embodiment so that holes 14 will not be partially blocked by flanges 19 and 21 if headers 11 and 12 are slightly rotated relative to heat exchange panel 13 during the heat bonding assembly phase. Holes 14 in header 12 are specifically placed so that they will not lie directly opposite holes 14 in header 11 in the unitary assembly 10. This staggered condition of holes 14 in headers 11 and 12 is for the purpose of reducing preferential water flow routes through heat exchange panel 13. Water is allowed to flow laterally in panel 13 through plenum chambers 22 so that water enters all tubular passages 17. Low resistance to flow would exist in some passages 17 if holes 14 were directly opposite each other in the headers. In this fashion a greater heat exchange efficiency is achieved, since there is fluid in motion beneath the entire surface of panel 13. The flow rates attained across the widths of all of the panels 13 is evidenced by a substantially similar temperature across the array of panels 13 during operation.
An additional embodiment of the unitary heat exchange panel 10 has an external appearance similar to that of FIG. 1, but the cross section equivalent to FIG. 3 appears as shown in FIG. 7. While only header 12 is shown in FIG. 7 an identical construction is utilized at the other end of panel 13 involving header 11. A continuous slot 38 is formed through one wall of header 12. Slot 38 has a length and width sufficient to accept the width and thickness of panel 13 respectively. A restriction of the ends 39 of passages 17 is undertaken on each end of panel 13. The restriction is obtained by either depositing a material which remains permanently affixed in the passage ends 39 or by forming the ends 39 to reduce the cross section of passages 17 at ends 39. The forming process is performed by using a solvent or a heated die on the ends of panel 13 for example.
Assembly of the panel 13 having restricted ends 39 in passages 17 with headers 11 and 12 having slots 38 is accomplished as follows. The end of panel 13 is inserted into slot 38 and bonded in place with the passages 17 in communication with the interior of header 12. An adhesive fillet 41 is placed around the junction between panel 13 and header 12 for sealing of the slot 38 and for providing structural strength in the assembly.
Another embodiment of unitary heat exchange assemblies 10 is shown in FIG. 8. Each corner of panel 13 is cut on a diagonal 42 and the ends of passages 17 terminating at diagonal 42 are sealed closed. Headers 11 and 12 are cut to the same dimension as the width of panels 13. The unitary assemblies 10 when connected together with collar 33 and clamps 34 are positioned so that the edges of panels 13 are abutting. This provides an advantage in space required by a plurality of assemblies 10, but suffers from the disadvantage of losing flow passages 17 on each edge of each panel 13.
The operation of the embodiment of FIG. 7 follows. Inlet fluid is delivered to the interior of header 12. Flow continues through restrictions 39 into passages 17. Heat is exchanged through the walls of panel 13 between the panel environment and the flowing fluid. Fluid exits panel 13 at restrictions 39 at the opposite end of panel 13 entering the interior of header 11. Flow passes from header 11 to a return conduit to a fluid reservoir, such as a swimming pool.
Restrictions 39 are sufficiently small to impede fluid flow enough to prevent preferential flow routes and stagnation in other flow routes through a panel or array of panels 13. It should be noted that flow rates may vary from panel to panel, that stagnation is prevented and an appreciable flow is maintained through all passages 17 of all panels 13.
A unitary heat exchange panel has been disclosed which may be used as a solar heater for swimming pools, and which may be used during the sunlight hours to elevate the temperature of the pool water and during the hours of darkness for depressing the temperature of the pool water if so desired. The heat exchange assembly is of relatively simple construction and lends itself to a fabrication method that is also relatively simple. | A panel having multiple tubular passages extending therethrough and fitted on each end with a fluid tight hollow header. Apertures through one side of the headers place the tubular passages in communication with the interior of the headers. Fluid pumped into one header flows through the tubular passages to the other header, exchanging heat with the environment surrounding the panel as it passes therethrough. The panels are formed to provide a flow restrictive feature at the ends of the through fluid passages so that substantial flow will exist in all passages in all panels in an array of panels. One method for obtaining a fluid tight bond between the headers and the panel involves a forming process utilizing a heated die applied to the panel ends, and a subsequent panel and header material melting process followed by imposing pressure contact between the formed panel ends and the headers to thereby effect a permanent bond or weld. | 1 |
This application is a continuation of application Ser. No. 126,726, filed Mar. 3, 1980, now abandoned, which in turn is a continuation-in-part of application Ser. No. 959,935, filed Nov. 13, 1978, now U.S. Pat. No. 4,208,293.
BACKGROUND
In order to conserve energy, automobiles are now being engineered to give improved gasoline mileage compared to those in recent years. This effort is of great urgency as a result of Federal regulations recently enacted which compel auto manufacturers to achieve prescribed gasoline mileage. These regulations are to conserve crude oil. In an effort to achieve the required mileage, new cars are being down-sized and made much lighter. However, there are limits in this approach beyond which the cars will not accommodate a typical family.
Another way to improve fuel mileage is to reduce engine friction. The present invention is concerned with this latter approach.
Polyethoxylated oleamide containing an average of 5 oxyethylene units is commercially available under the name "Ethomid" (registered trademark, Armak Company). Reference to its use as a demulsifier in lubricating oil appears in U.S. Pat. No. 3,509,052.
SUMMARY
According to the present invention, lubricating oils are provided which reduce friction between sliding metal surfaces in internal combustion engines. The reduced friction results from the addition to the lubricating oil of a small amount of a fatty acid amide or ester of diethanol amine.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A preferred embodiment of the invention is a lubricating oil composition comprising a major amount of lubricating oil and a minor friction-reducing amount of an oil-soluble additive selected from the group consisting of fatty acid amides of diethanolamine, fatty acid esters of diethanolamine, fatty acid ester-amides of diethanolamine and mixtures thereof.
The additives can be made by forming a mixture of a fatty acid and diethanolamine and heating the mixture to remove water. Optionally, a water immiscible inert solvent such as toluene or xylene can be included to aid in the removal of water.
About 0.8-3 moles, more preferably 1-3 moles of fatty acid are used per mole of diethanolamine. The reaction proceeds to yield mainly amide according to the following equation: ##STR1## wherein R is a hydrocarbon residue of the fatty acid.
Some of the diethanolamine can react to form ester according to the following equation: ##STR2##
Because of the relative low reactivity of the hydroxy group, the second main components are the fatty acid ester-amides of diethanolamine formed according to the following equations: ##STR3## Such ester-amides are within the scope of the invention.
In practice when oleic acid is reacted with diethanolamine in approximately equal mole amounts, the principal component has been found to be N,N-bis-(2-hydroxyethyl)oleamide in amounts of about 50-80 weight percent. Lesser amounts of about 10-40 weight percent of 2-[N-(2-hydroxyethyl)oleamido]ethyl oleate also forms.
Preferred fatty acids used in making the friction-reducing additive are those containing about 8-20 carbon atoms. Examples of these are caprylic acid, pelargonic acid, capric acid, undecylic acid, lauric acid, tridecoic acid, myristic acid, stearic acid, arachidic acid and the like.
More preferably the fatty acid is an unsaturated fatty acid such as hypogeic acid, oleic acid, linoleic, elaidic acid, erucic acid, brassidic acid, tall oil fatty acids and the like.
More preferably the fatty acid is oleic acid. Thus, the preferred additives are N,N-bis-(2-hydroxyethyl)oleamide, and 2-[N-(2-hydroxyethyl)oleamido]ethyl oleate and mixtures thereof.
The components can be separated by distillation and used separately in lubricating oil compositions. Preferably they are not separated, but are used as mixtures. The reaction mixtures contain other minor components which have not been identified, but are believed to contribute to the friction-reducing properties of the reaction mixture. Hence, a most preferred embodiment of the invention is a product made by the process comprising reacting (a) about 0.8-3 moles of a C 8-20 fatty acid or fatty acid producing compound with (b) one mole of diethanolamine, while removing water formed in the reaction, said improvement resulting in reduced engine friction and improved fuel economy.
Fatty acid producing compounds can be used in place of the fatty acid. These include fatty acid anhydrides, esters, halides, ammonium salts and the like. For example, methyl oleate will react with diethanolamine in a manner similar to oleic acid by liberation of methanol which can be distilled out much like water. Such reaction mixtures are included within the scope of the invention.
The following examples serve to illustrate the method of making the present additive.
EXAMPLE 1
In a reaction vessel was placed 52.5 gms (0.5 mol) of diethanolamine and 141 gms (0.5 mol) of oleic acid (caution exotherm). The mixture was stirred under nitrogen and heated to 188° C. over a two-hour 13-minute period while distilling out water. The resultant product was mainly N,N-(2-hydroxyethyl)oleamide.
EXAMPLE 2
In a reaction vessel was placed 282 gms of oleic acid, 105 gms diethanol amine and a small amount of xylene. The mixture was stirred under nitrogenand heated from 165°-185° C. over a two-hour period while distilling out water and returning xylene. The xylene was then stripped from the mixture under vacuum leaving 363 gms of a viscous liquid product consisting mainly of N,N-bis-(2-hydroxyethyl)oleamide.
EXAMPLE 3
In a reaction vessel was placed 5085 gms of oleic acid, 1893 gms diethanolamine and 1300 ml toluene. The mixture was heated to reflux (135°-151° C.) under nitrogen. Water was distilled out over a 4-hour period using a Dean-Stark water separator. Following this, toluene was distilled out by heating to 120° at 20 mm Hg abs. The acid number of the reaction product was 4.91 mg KOH/g. The reaction product was heated at 95° C. at 50 mm Hg abs for 64 hours. After this heat treatment, the acid number was lowered to 1.85. The product was subjected to high pressure liquid chromatography (HPLC) treatment to separate it into its components. Six components were isolated. Two of the principal components were identified by infrared, NMR and elemental analysis to be N,N-bis-(2-hydroxyethyl)oleamide (52.9%) and 2-[N-(2-hydroxyethyl)oleamido]ethyl oleate (35.7%). This reaction product was an excellent friction reducer.
EXAMPLE 4
In a reaction vessel was placed 5084.5 gms oleic acid, 1892.5 gms diethanolamine and 1300 ml toluene. The mixture was stirred and heated, distilling off water and toluene using a Dean-Stark separator up to a temperature of 163° C. Pressure was then reduced to 30 mm Hg abs and residual water and toluene were distilled out up to 105° C. (60° C. overhead). This product was analyzed by HPLC to be 67% N,N-bis-(2-hydroxyethyl)oleamide and 24.8% 2-[N-(2-hydroxyethyl)oleamido]ethyl oleate. This reaction mixture was an effective fuel economy additive in formulated motor oil.
Other fatty acids can be substituted for oleic acid in the above examples with good results. Alternatively, the amide can be made by reacting one mole of oleamide with about two moles of ethylene oxide. The additives areused in an amount sufficient to reduce the sliding friction of metal surfaces lubricated by oil containing the additive. An effective concentration is about 0.05-5 weight percent. More preferably, the use concentration is about 0.2-1 weight percent.
The base lubricating oil may be mineral lubricating oil or synthetic lubricating oil. Useful mineral oils include all those of suitable lubricating viscosity. Representative synthetic oils include olefin oligomers such as α-decene trimer and tetramer, alkyl benzenes such as didodecyl benzene, esters such as dinonyl adipate, trimethylolpropane tripelargonate, and complex esters made from polycarboxylic acids and polyols with a monocarboxylic acid or monohydric alkanol end group.
Blends of mineral oil and synthetic oil are very useful. For example, a blend of about 80% 150 SUS mineral oil and 20% α-decene trimer givesa very useful base lubricating oil. Likewise, blends of synthetic esters with mineral oil are very useful. For example, a blend of 15 weight percent di-2-ethylhexyl adipate and 85 weight percent 150 SUS mineral oil is a very effective base lubricating oil for use in an engine crankcase.
Improved results are obtained when a zinc dihydrocarbyl dithiophosphate (ZDDP) is used in combination with the present additives. The amount can vary over a wide range. It is usually expressed in terms of zinc content of the oil. Formulated oil would include 0.01-0.3 weight percent zinc as ZDDP. A preferred range is about 0.05-0.15 weight percent zinc.
The ZDDP may be aryl type or alkyl type. A representative aryl type ZDDP iszinc di-nonylphenyl dithiophosphate. Preferably, an alkyl type ZDDP is used. Examples of these are zinc isobutyl amyl dithiophosphate, zinc di-(2-ethylhexyl)dithiophosphate and the like.
Other additives may be included such as alkaline earth metal phenates and sulfurized phenates, alkaline earth hydrocarbyl sulfonates such as calciumpetroleum sulfonate, magnesium alkyl benzene sulfonate, overbased calcium alkyl benzene sulfonate and the like. Phosphosulfuried terpene and polyolefins and their alkaline earth metal salts may be included. Viscosity index improvers such as the poly-alkyl methacrylate or ethylene-propylene copolymers, ethylenepropylene non-conjugated diene terpolymers are also useful VI improvers in lubricating oil. Antioxidants such as 4,4'-methylenebis-(2,6-di-tert-butylphenol) can be beneficially added to the lubricating oil.
Tests were carried out which demonstrated the friction-reducing properties of the additives. These tests have been found to correlate with fuel economy tests in automobiles. In these tests an engine with its cylinder head removed and with the test lubricating oil in its crankcase was brought to 1800 rpm by external drive. Crankcase oil was maintained at 63° C. The external drive was disconnected and the time to coast toa stop was measured. This was repeated several times with the base oil and then several times with the same oil containing one percent of a mixture prepared as described in Examples 2 and 3. The base oil was a typical commercial oil formulated for use in a crankcase. The friction-reducing additives were found to increase the coast-down time an average of 4.3% and 8.2% respectively.
Further tests were carried out in a 1977 automobile fitted with a 403 CID V8 engine. The test used was the modification of the Federal EPC city cycle. It consisted of a first 3.6 miles of the Federal EPA city cycle starting with a warmed up engine. It is referred to as the "Hot 505" cycle.
The above 1977 car with a fully formulated commercial SE grade 10W40 motor oil in its crankcase was operated on a chassis dynamometer for about one hour at 55 mph to stabilize oil temperature. It was then run through a series of three consecutive "Hot 505" cycles during which its fuel consumption was carefully measured. These results were averaged to obtain the baseline fuel economy of the car.
One-half of the oil in the engine crankcase was then removed and replaced with an equal amount of the same oil except containing 2 weight percent ofan oleamide of diethanolamine consisting of about 60 wt % N,N-bis-(2-hydroxyethyl)oleamide and 30 wt % 2-[N-(2-hydroxyethyl)oleamido] ethyl oleate. This resulted in a crankcase oil containing 1 weight percent of the test additive. The car was then operated on the chassis dynamometer at 55 mph for one hour to again stabilize temperature. Then a second series of three consecutive "Hot 505"cycles was conducted while carefully measuring fuel economy. These results were averaged to give the "initial" fuel economy of the engine with the test additive.
The same 1977 Oldsmobile was operated the equivalent of 500 miles at 55 mphon the chassis dynamometer following which a third series of three consecutive "Hot 505" cycles were run while carefully measuring fuel economy. These results were averaged to give the fuel economy after 500 miles operation with the test additive.
The engine crankcase was then drained while hot and filled with flushing oil. It was operated for a short time and drained again. The crankcase wasthen filled with the same 10W40 motor oil not containing the test additive.The engine was run for a short time and then drained. It was refilled with the same 10W40 motor oil not containing the test additive. The engine was operated at 55 mph on the chassis dynamometer for about one hour to stabilize engine temperature. Then a fourth series of three consecutive "Hot 505" cycles was carried out while carefully measuring fuel economy. These results were averaged to obtain a final baseline thereby bracketing the tests conducted with the test additive between two baseline results.
The following table shows the results of the above-described test:
______________________________________ Fuel Economy (mpg) initial after 500 miles______________________________________1. first baseline 16.622. with 1 wt % of 16.80 16.80 oleic amide of diethanolamine3. second baseline 16.50______________________________________
These results show that the addition of 1 weight percent of the mixture of oleamides of diethanolamine to a fully formulated engine crankcase oil gave an initial improvement in fuel economy of 1.1% and an improvement of 1.8% after 500 miles.
A second test series was conducted to measure the fuel economy properties of the mixture of oleamides of diethanolamine. This test series was conducted using a 1978 Chevrolet with a 302 CID V-8 engine. The engine crankcase was drained and filled with a commercial SE grade 10W40 motor oil. This was operated about 10 minutes and then drained. The crankcase was again filled with the same 10W40 motor oil. The engine was operated about 10 minutes and then drained. The crankcase was filled a third time with the same 10W40 motor oil. The car was then operated the equivalent of1,000 miles at 55 mph on a chassis dynamometer. Following this the car was operated through the full 1975 Federal EPA city cycle starting with a warmed-up engine. Fuel consumption was carefully measured. The car was then operated through the full 1975 Federal EPA highway cycle. Fuel consumption was carefully measured. The car was then operated through boththe city and highway cycle two more times while measuring fuel consumption.These results were averaged to obtain a first baseline.
The same 1978 Chevrolet was then taken through the same procedure set forthin the previous paragraph except that this time 0.5 weight percent of the mixture of oleamides of diethanolamine was added to the commercial SE 10W40 motor oil. The four city and four highway results were averaged to give a city and highway fuel economy rating for the car with 0.5 weight percent of the test additive.
Following this, the same 1978 Chevrolet was taken through the same procedure set forth two paragraphs above using the same commercial SE 10W40 motor oil without the test additive. The four city and four highway results were averaged to give a second city and highway baseline fuel economy rating.
The first and second baseline fuel economy ratings were subjected to linearregression analysis to develop a statistical baseline which takes into account variations in barometric pressure, humidity and any trend in baseline economy which developed during the test in order to obtain a statistically significant baseline.
The following table sets forth the results of the test with the 1978 Chevrolet:
______________________________________ City Cycle (mpg) Highway (mpg)______________________________________1. statistical baseline 15.13 19.522. with 0.5% mixture of 15.27 19.68 oleamides of diethanol- amine3. percent improvement 0.9 0.8______________________________________
That statistical analysis of the above data showed that the improvement in fuel economy is real with 99% confidence. | Lubricating oil adapted for use as a crankcase lubricant in internal combustion engines containing a friction-reducing amount of a fatty acid amide or ester of diethanolamine. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to attachment apparatus for two-wheeled vehicle parts and, more particularly, to an attachment apparatus for use in attaching bicycle parts such as a head lamp or the like to a bicycle.
2. Description of the Background Art
FIG. 23 is a side view of a head lamp for a bicycle that is attached to a handle of the bicycle by employing a conventional attachment method; and FIG. 24 is a front view showing the attachment of the bicycle head lamp of FIG. 23.
Referring to FIGS. 23 and 24, an attachment part A51 that includes an upper member 55 pivotal on a pin 11 and a lower member 57 is attached through a rubber 31 to a handle 27. An attachment part B53 attached to a lower portion of a head lamp 29 is slidably engaged with an upper portion of upper member 55.
FIG. 25 is an exploded perspective view showing the state where attachment parts A51 and B53 shown in FIGS. 23 and 24 are detached.
Referring to FIG. 25, a pair of rail members 59a and 59b are formed in the upper portion of attachment part A51. A tapped hole 13 is formed between rail members 59a and 59b. A recess 63 is formed in a portion in an opposite direction from the direction of tapped hole 13 between rail members 59a and 59b. Attachment part A51 is formed of upper member 55 and lower member 57, which are both pivotal on pin 11. This allows attachment part A51 to be attached to tubular component parts of the bicycle such as a handle or the like.
Grooves 60a and 60b that are slidable with respect to rail members 59a and 59b of attachment part A51 are formed in a lower portion of attachment part B53. A flat engagement piece 61 partially projected from attachment part A51 is formed between grooves 60a and 60b. An attachment hole 23 is an aperture provided for attaching attachment part B53 to head lamp 29 by employing a screw or the like.
FIG. 26 is a view showing the state where grooves 60a and 60b of attachment part B53 in the conventional example are sliding while fitting on rail members 59a and 59b of attachment part A51.
Referring to FIG. 26, engagement piece 61 that is made of, e.g., plastic resin and attached to the lower portion of attachment part A51 has a projection 65 formed in its lower portion. Projection 65 is in the form of being engaged with recess 63. As shown in FIG. 26, when attachment part B53 moves in an "A" direction, a spheroidal portion of a tip end of engagement piece 61 first makes contact with a protrusion 64 of upper member 55 of attachment part A51. Since engagement piece 61 is formed of plastic resin, engagement piece 61 deforms to deflect upward so that engagement piece 61 may avoid a collision caused by the contact with protrusion 64. Then, engagement piece 61 deforms further upward by contacts between projection 65 and protrusion 64.
FIG. 27 is a cross-sectional view showing the state where attachment parts A51 and B53 are completely engaged with each other from the state shown in FIG. 26.
Referring to FIG. 27, projection 65 on engagement piece 61 is engaged with recess 63 formed in upper member 55 when going completely beyond protrusion 64. This engagement between projection 65 and recess 63 prevents disengagement of attachment part B53 even if a force is applied in a direction in which attachment part B53 is disengaged, i.e., a "B" direction.
A sufficient attachment strength is not provided in the above-described conventional attachment apparatus for bicycle parts. With reference to FIG. 27, attachment part B53 is not detached from attachment part A51 due to the engagement between projection 65 and recess 63 in the stage that a small force is applied in the "B" direction. However, as shown in FIG. 26, engagement piece 61 has an elastic state such as of plastic resin. Thus, when a force larger than a predetermined force is applied in the "B" direction, engagement piece 61 is liable to be deformed in such form as shown in FIG. 26 by the applied force, thereby releasing the engagement. As described above, there is no sufficient reliability in the engagement between attachment parts A51 and B53. Particularly, no sufficient attachment strength is provided in view of vibration applied by the use of bicycles or the like.
SUMMARY OF THE INVENTION
One object of the present invention is to provide an attachment apparatus for two-wheeled vehicle parts capable of easily attaching the two-wheeled vehicle parts.
Another object of the present invention is to provide an attachment apparatus for two-wheeled vehicle parts capable of firmly attaching the two-wheeled vehicle parts.
A further object of the present invention is to provide a highly economical attachment apparatus for enhancing a reliability in attachment of parts for a two-wheeled vehicle.
To accomplish the foregoing objects, an attachment apparatus for two-wheeled vehicle parts in accordance with the present invention includes: first attachment means detachably attached to component parts of a two-wheeled vehicle; second fixing means fixed to parts for the two-wheeled vehicle; a pair of fitting means being mutually fitted, wherein one fitting means is provided in one of the first and second attachment means, and the other fitting means is provided in the other of the first and second attachment means; and preventing means movably provided in one of the fitting means pair, for preventing a release of the fitting of the fitting means in a predetermined moving position.
The attachment apparatus for two-wheeled vehicle parts thus structured allows the two-wheeled vehicle parts to be firmly attached to component parts of a two-wheeled vehicle by function of the preventing means.
The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
There is shown in the attached drawing a presently preferred embodiment of the present invention, wherein like numerals in the various views refer to like elements, and where:
FIG. 1 is a perspective view showing the state where engagement between attachment parts A and B is released according to one embodiment of the present invention.
FIG. 2 is a side view showing the state of a bicycle with a head lamp attached thereto according to the one embodiment of the present invention.
FIG. 3 is a side view showing a detailed structure in which the head lamp of FIG. 2 is attached to a handle.
FIG. 4 is a view of the attached head lamp of FIG. 3 viewed from the front side.
FIG. 5 is a view of the attached head lamp of FIG. 3 viewed from the back side.
FIG. 6 is a plan view of attachment part B of FIG. 1.
FIG. 7 is a rear view of attachment part B shown in FIG. 6.
FIG. 8 is a cross-sectional view taken along the line VIII--VIII of FIG. 6.
FIG. 9 is a plan view of attachment part B of FIG. 1, showing the state where a stopper 19 is moved against a resilient force of a spring.
FIG. 10 is a rear view of attachment part B of FIG. 9.
FIG. 11 is a cross-sectional view taken along the line XI--XI of FIG. 9.
FIG. 12 is a cross-sectional view taken along the line XII--XII of FIG. 1.
FIG. 13 is a cross-sectional view taken along the line XIII--XIII of FIG. 1.
FIG. 14 is a perspective view showing structure of stopper 19 of FIG. 1.
FIGS. 15(a), 15(b) and 15(c) are views showing changes in the state of engagement between rail members of attachment part A and grooves of attachment part B.
FIG. 16 is an enlarged plan view of a portion of "X" of FIG. 6.
FIG. 17 is a cross-sectional view taken along the line XVII--XVII of FIG. 16.
FIG. 18 is a corresponding view of FIG. 16, showing the state where stopper 19 is moved against a spring 21.
FIG. 19 is a view showing an attachment state of a head lamp 29 according to another embodiment of the present invention.
FIG. 20 is a view of the attached head lamp of FIG. 19 viewed from the back side.
FIG. 21 is a top view of attachment part B of FIG. 20.
FIG. 22 is a top view of attachment part B of FIG. 20, showing the state where stopper 19 is moved against the resilient force of spring 21.
FIG. 23 is a side view showing the state of attachment of a conventional head lamp 29.
FIG. 24 is a view of the attached head lamp of FIG. 23 viewed from the front side.
FIG. 25 is a perspective view of the state where engagement between attachment parts A and B shown in FIG. 23 is released.
FIG. 26 is a cross-sectional view showing the state where the engagement between attachment parts A and B of FIG. 25 is moved.
FIG. 27 is a cross-sectional view showing the state where the engagement between attachment parts A and B of FIG. 25 is completed.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 2 is a side view showing the state where a head lamp 29 is attached to a handle 27 of a bicycle 25 by an attachment apparatus according to one embodiment of the present invention.
FIG. 3 is a side view showing a detailed structure in which head lamp 29 is attached to handle 27 of FIG. 2; FIG. 4 is a front view of such structure; and FIG. 5 is a rear view thereof.
Referring to FIGS. 2, 3, 4 and 5, an attachment part 1 comprises an upper member 3 that is pivotal on a pin 12 and a lower member 5. For attaching attachment part A1 to handle 27 of the bicycle, with a screw 33 being detached, upper member 3 and lower member 5 are pivoted on a pin 11 so that their respective end portions may extend around the pin, and a rubber like resilent shin or filler 31 is lapped or positioned around bicycle handle 27 to be interposed between upper and lower members 3 and 5 and handle 27. Then, fastening a screw 33 causes a force to be applied to upper and lower members 3 and 5 to interpose handle 27 between upper and lower members 3 and 5, whereby attachment part A1 is firmly attached through rubber 31 to handle 27. A switching button 35 for controlling a turn-on/off of head lamp 29 is attached to a rear portion of head lamp 29. An attachment part B15 is attached to a lower portion of head lamp 29 by using a screw or the like. A lever 20 for use in detachment from attachment part A1 is provided in a rear portion of attachment part B15.
FIG. 1 is an exploded perspective view showing the state where the engagement between attachment parts A and B shown in FIGS. 3-5 is released; FIG. 12 is a cross-sectional view taken along the line XII--XII of FIG. 1; and FIG. 13 is a cross-sectional view taken along the line XIII--XIII of FIG. 1.
Like the conventional example, a pair of rail members 7a and 7b are formed in an upper portion of attachment part A with reference to the figures. However, respective recesses 9a and 9b are provided in respective end portions of respective rail members 7a and 7b. The form of a tapped hole 13 for setting a screw for fastening upper and lower members 3 and 5 and the form of pin 11 for pivoting of those members are the same as those in the conventional example.
Grooves 17a and 17b to be engaged with rail members 7a and 7b respectively are formed in a lower portion of attachment part B15. A stopper 19 for controlling an engagement between attachment parts A and B is provided on a top surface of attachment part B. A spring 21 is incorporated in stopper 19 as shown in FIG. 1. An attachment hole 23 for attaching attachment part B15 to the head lamp is the same as the one in the conventional example.
FIG. 6 is a plan view of attachment part B shown in FIG. 1; FIG. 7 is a rear view of attachment part B; and FIG. 8 is a cross-sectional view taken along the line VIII--VIII of FIG. 6.
Stopper 19 is T-shaped as viewed in plane as shown in FIG. 14. A lever 20 is provided below the central portion of the T-shape. Triangular jutted portions 37a and 37b in plane are formed in opposite end directions of the T-shape. A pin-like projection 22 which is projected to prevent the falling-off of spring 21 is provided in a portion corresponding to an upper portion of the T-shape. With reference to FIGS. 6-8, stopper 19 is moving upward in FIG. 6 by a resilient force of spring 21. At this time, as shown in FIGS. 7 and 8, jutted portions 37a and 37b of stopper 19 are positioned in directions for crossing over respective grooves 17a and 17b.
FIGS. 9-11 are views corresponding to FIGS. 6-8 shown before, respectively, showing the state where stopper 19 is moved downward in FIG. 9 against the resilient force of spring 21 by using lever 20.
In this state, as shown in FIG. 10, respective jutted portions 37a and 37b of stopper 19 that are positioned in the direction for crossing over grooves 17a and 17b are moved upward in FIG. 10. Accordingly, as shown in FIG. 11 also, neither jutted portions 37a nor 37b prevent movement of rail members 7a and 7b sliding in grooves 17a and 17b.
FIGS. 15(a), 15(b) and 15(c) are views showing the state of engagement between the rail members of attachment part A and the grooves of attachment part B when attachment parts A and B are engaged with each other.
FIG. 15 (a) shows the state where rail members 7a and 7b are being engaged with grooves 17a and 17b of attachment part B, and tip end portions of rail members 7a and 7b have not yet reached jutted portions 37a and 37b of stopper 19. As shown in FIGS. 6 and 7, jutted portions 37a and 37b are positioned so that portions of jutted portions 37a and 37b may be projected in the direction for crossing over grooves 17a and 17b by the resilient force of spring 21.
FIG. 15 (b) shows the state where rail members 7a and 7b further move, so that their tip ends have reached jutted portions 37a and 37b.
In this case, the tip end portions of jutted portions 37a and 37b are formed obliquely as shown in the figure. Accordingly, by a force to be applied in the arrowed direction of rail members 7a and 7b, jutted portions 37a and 37b gradually move upward in the drawing against the resilient force of spring 21.
Referring to FIG. 15 (c), the tip ends of rail members 7a and 7b completely force jutted portions 37a and 37b upward in the drawing and pass through the corresponding portions, so that rail members 7a and 7b are completely engaged with jutted portions 37a and 37b. Jutted portions 37a and 37b forced upward in the state of FIG. 15 (b) move downward in FIG. 15 (c) by the resilient force of spring 21, and are then completely fit into recesses 9a and 9b which are of the form corresponding to the form of jutted portions 37a and 37b and are provided in rail members 7a and 7b. With attachment parts A and B thus attached to each other by the fitting of the rail members and the groove members, even if a force is applied to rail members 7a and 7b in a direction for detaching attachment part A, i.e., a "B" direction, the engagement between jutted portions 37a and 37b and recesses 9a and 9b is not released. This is because the direction of the force applied in the "B" direction and the direction of the force applied to jutted portions 37a and 37b by spring 21 are not identical but orthogonal to each other.
Detachment of attachment part B from the state of FIG. 15 (c) is enabled by moving lever 20 of stopper 19 from the state of FIG. 6 to the state of FIG. 9. That is, when stopper 19 is moved against the resilient force of spring 21 by operation of lever 20, jutted portions 37a and 37b stand away from grooves 17a and 17b as shown in FIG. 10. Accordingly, the fitting of recesses 9a and 9b is released, thereby facilitating the disengagement between rail members 7a and 7b and grooves 17a and 17b.
FIG. 16 is an enlarged view of the "X" portion of FIG. 6; and FIG. 17 is a cross-sectional view taken along the line XVII--XVII of FIG. 16.
As shown in FIGS. 16 and 17, the end portion of stopper 19 has a projection 43. A projection 41 is formed in a main body 16 of attachment part B15 above projection 43 in the position of FIG. 16. Accordingly, in the state of FIG. 6, i.e., when stopper 19 is moving upward by the resilient force of spring 21, projections 43 and 41 vertically overlap with each other. Thus, in this state, even if stopper 19 disposed in a stopper receiver 18 is intended to be detached upward, the detachment is prevented by overlapping projections 43 and 41. This makes it possible to prevent stopper 19 from easily falling off attachment part B.
FIG. 18 shows the state where stopper 19 thus formed is moved downward against the resilient force of spring 21 by operation of lever 20 as shown in FIG. 9. In this state, there is no vertical overlapping between projection 43 of stopper 19 and projection 41 formed in main body 16 of attachment part B. Therefore, in this state, lifting stopper 19 upward allows stopper 19 to be detached from attachment part B. While projections 43 and 41 are formed on only one end portion of T-shaped stopper 19, provision of such projections also on the other end portion of stopper 19 results in a higher reliability in detachment of stopper 19.
FIG. 19 is a side view showing an attachment apparatus for bicycle parts according to another embodiment of the present invention; and FIG. 20 is a rear view of such attachment apparatus.
Unlike the former embodiment, an attachment part A47 having a rail member is provided on the side of head lamp 29, and a groove which is formed to fit on the rail member of attachment part A47 is formed in an attachment part B45 fixed onto handle 27, in FIGS. 19 and 20. Accordingly, in this embodiment, stopper 19 employed to disengage attachment parts A47 and B45 is provided on an upper member 3 of attachment part B45.
While it is necessary to manufacture attachment part B and head lamp 29 separately in the former embodiment, according to this embodiment thus structured, a stopper or the like is unnecessary for attachment part A47, so that attachment part A47 and lower members of head lamp 29 can integrally be formed such as by plastic resin.
FIG. 21 is a plan view of upper member 3 of attachment part B45 of FIG. 20; and FIG. 22 is a plan view showing the state where stopper 19 is moved upward in the drawing against the resilient force of spring 21.
Since the fitting state or the like of the rail member formed on attachment part A47 as an operation of the engagement between jutted portions 37a and 37b formed in stopper 19 and grooves 17a and 17b is the same as the one shown in the former embodiment, a description thereof will not be repeated. In the attachment apparatus thus structured, since stopper 19 is provided on the fixing side, the shape of the attachment part on the side of bicycle parts becomes simple and more economical particularly when various bicycle parts are exchanged and attached to the bicycle.
While stopper 19 is always enforced in a definite direction by employing a spring in the foregoing embodiment, other enforcing means than the spring can be employed and, even if such enforcing means is not employed, a highly reliable attachment effect as compared with the conventional example can be expected.
While a head lamp is used as bicycle parts in the foregoing embodiment, the present invention is similarly applicable to other bicycle parts as a matter of course.
While the present invention is applied to the attachment of component parts of the bicycle in the foregoing embodiment, the present invention is applicable as a method of attaching various types of parts to not only bicycles but also any two-wheeled vehicles and other objects.
Although the present invention has been described and illustrated in detail, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, the spirit and scope of the present invention being limited only by the terms of the appended claims. | An attachment apparatus for two-wheeled vehicle parts in accordance with the present invention includes: a first fitting portion formed on an attachment part attached to component parts of a two-wheeled vehicle and having a single rail-shaped projection that has its one end open and has a recess formed in a portion of the projection; and a second fitting portion formed on an attachment part fixed to the two-wheeled vehicle parts and including a single groove that is slidably fit on the rail-shaped projection and including a projection piece having a jutted portion formed on a tip end of the projection piece and movable in a direction of crossing over the groove, the jutted portion being engaged with the recess of the projection in the groove. When a second attachment part is attached to a first attachment part by a fitting of the first and second fitting portions, the projected piece moves with the projection fit in the groove, so that the recess and the jutted portion are engaged with each other, thereby preventing a release of the fitting of the first and second fitting portions. | 1 |
FIELD OF THE INVENTION
[0001] This invention relates generally to food additives and, more particularly to a new process for the simplified production of phytosterols.
PRIOR ART
[0002] Phytosterols and their esters possess hypocholesterolaemic properties, i.e. these substances are capable of lowering the cholesterol level in the blood. Accordingly, they are used as food additives, for example for the production of margarine, frying oils, sausage, ice cream and the like. The production of sterols and other unsaponifiable constituents, such as tocopherols for example, from distillates obtained in the deacidification of vegetable oils, has already been variously described in the patent literature, cf. EP-A2 0 610 742 (Hoffmann-LaRoche), GB-A1 2,145,079 (Nisshin Oil Mills Japan) and EP-A1 0 333 472 (Palm Oil Research and Development Board).
[0003] European Patent EP-B1 0 656 894 (Henkel) describes a process for the production of sterols in which a residue from the distillation of methyl esters consisting essentially of glycerides, sterols, sterol esters and tocopherols is transesterified with methanol in the presence of alkaline catalysts. After neutralization of the catalyst, removal of the excess methanol by distillation and, optionally, removal of the catalyst by washing, the sterols are crystallized by lowering the reaction temperature from about 65 to 20° C. The crystals obtained are then washed with methanol and water. Unfortunately, the yield of sterols is unsatisfactory.
[0004] Accordingly, the problem addressed by the present invention was to provide phytosterols in high yields and to simplify existing known processes.
DESCRIPTION OF THE INVENTION
[0005] The present invention relates to a process for the recovery of phytosterols from mixtures with fatty acid esters and methanol by crystallization known per se, filtration, washing and drying, characterized in that methanol is used in quantities of 25 to 75% by weight, based on the sterols.
[0006] It has surprisingly been found that the crystallization temperature of the sterols is significantly influenced by the methanol content in the reaction mixture. Thus, the melting temperature of a mixture with a methanol content of 30% by weight rises from 65 to 78° C. in relation to an alcohol-free fraction. Not only does this simplify the process and improve the energy balance, distinctly higher yields are also obtained in the subsequent working up phase. The invention includes the observation that the rise in the crystallization temperature is not a linear function of the methanol content because a rapid fall is observed at contents above about 75% by weight.
[0007] Transesterification
[0008] The production of a sterol-rich fraction by transesterification of residues from the deacidification of vegetable oils and subsequent working up can be carried out as described in EP-B1 0 656 894. Suitable starting materials are the distillation residues obtained, for example, as so-called deodorizer condensates in the production of fatty acid methyl esters based on rapeseed oil or, more particularly, sunflower oil. Tall oil pitch, more particularly pitch obtained from birch bark, is also suitable. Where it relates to the production of the sterol fractions, reference is comprehensively made to the document cited above. The process is particularly suitable for the production of sterols based on vegetable oils which have only a small percentage content of α-sitosterols. Accordingly, preferred starting materials are phytosterol-rich fractions from the transesterification of rapeseed oil (“rapeseed sterols”) or soybean oil (“soya sterols”).
[0009] Crystallization
[0010] The crystallization of the sterol fractions which, apart from the alcohol, mainly contain methyl esters takes place in known manner, i.e. the hot mixtures (ca. 90 to 100° C.) are slowly cooled to around 10° C. in a crystallizer. If necessary, alkaline catalyst from the transesterification present in the mixture can be neutralized beforehand, for example by addition of citric acid. According to the invention, only those mixtures which already have a ratio by weight of sterol to methanol of 100:25 to 100:75 from their production should be used. Otherwise methanol has to be added or distilled off. Under these conditions, the crystallization begins at temperatures of 75 to 80° C. It is of course also possible to use crude sterols instead of the transesterification products, to add methanol and optionally methyl ester and to concentrate the whole in the described manner. If desired, the crude sterols may also be washed with methyl ester fractions. Although, in this case, small amounts of product are lost, a lasting improvement in color is obtained. The phytosterols accumulating are then removed and purified in known manner, i.e. filtered off, washed free from esters and dried to constant weight.
EXAMPLES
Comparison Example C1
[0011] The starting material used was a rapeseed methyl ester fraction which, based on the content of free and bound sterols, additionally contained 100% by weight of methanol. The mixture was continuously cooled from ca. 100° C. to 10° C., the first crystals beginning to separate at 68° C. On completion of the crystallization, the crystals were filtered off, washed free from methyl ester with methanol and dried to constant weight. The yield was 78% by weight, based on the sterol content of the transesterification product.
Comparison Example C2
[0012] Example C1 was repeated using a mixture containing 200% by weight of methanol, based on the quantity of sterol. In this case, the crystallization only began at 63° C. and the yield was 72% by weight. In the form of a 10% by weight solution in ethanol, the products have a Hazen color number of 798 and a Gardner color number of 4.4.
Comparison Example C3
[0013] Example C1 was repeated using a mixture containing 300% by weight of methanol, based on the quantity of sterol. In this case, the crystallization only began at 56° C. and the yield was 68% by weight.
Example 1
[0014] Example C1 was repeated using a mixture containing 30% by weight of methanol, based on the quantity of sterol. The crystallization began at 78° C. and the yield was 92% by weight.
Example2
[0015] 100 g of a crude soya sterol mixture (sterol content: 83% by weight) were dissolved in 186 g of cocofatty acid methyl ester at 90° C. and methanol was added to the resulting solution in such a quantity that a ratio by weight of sterol to methanol of 2:1 was obtained. After the temperature had fallen, the first sterol crystals separated at 74° C. On completion of crystallization, the crystals were filtered off, washed free from methyl ester with methanol and dried. The resulting fraction had a purity of 93.7% by weight. | Processes for recovering phytosterols are described. The processes comprise: (a) providing a liquid mixture containing a phytosterol, methanol, and one or more additional compounds, wherein the methanol is present in an amount of from 25 to 75% by weight, based on the phytosterol; (b) cooling the mixture to form phytosterol crystals; and (c) separating the phytosterol crystals from the remainder of the mixture. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a National Phase application of International Application No. PCT/PL2011/000047 filed May 5, 2011 which claims priority to Polish Patent Application No. PL P-391169 filed May 7, 2010, the disclosures of which are incorporated herein by reference.
The invention relates to a method of manufacturing the silica nanopowders with fungicidal properties, especially for polymer composites.
The requirements for materials used in medicine, pharmacy, household goods, textile and wood industry, are the reason for the necessity of impart the mixtures of high molecular compounds with bactericidal and fungicidal properties.
One can find in the literature the information on the use of copper nanoparticles, e.g. as an additive for cellulose fibers (Grace Mary, S. K. Bajpai, Navin Chand; Journal of Applied Polymer Science; vol. 113 Issue 2, 757-766), with biocidal properties against Escherichia coli. It was stated in the publication of Nicola Cioffi, Luisa Torsi, Nicoletta Ditaranto, Giuseppina Tantillo, Lina Ghibelli, Luigia Sabbatini, Teresa Bleve-Zacheo, Maria D'Alessio, P. Giorgio Zambonin, Enrico Traversa; 2005 American Chemical Society; vol. 17 (21), 5255-5262 that the entire inhibition or slowing down the growth of living organisms, such as pathogenic fungi and microorganisms has occurred after use of the additive in the form of copper nanoparticles in polymer composites.
Copper nanoparticles have evidently higher biocidal activity than microparticles of that element. The substantial problem is the immobilization of copper nanoparticles in silica. Authors of the publication (T. Lutz, C. Estrournes, J. C. Merle, J. L. Guille (Optical properties of cooper-dopes silica gels; Journal of Alloys and Compounds 262-263 (1997) 438-442) claimed that one of the useful method is the implantation of ions with use of laser of appropriate wavelength (ultraviolet).
The use of nanopowders containing copper nanoparticles immobilized in silica, as components of nanocomposites and nanomaterials, is possible with the provision that they have reproducible and defined composition and chemical structure.
From the patent specification U.S. Pat. No. 6,495,257, there is known a method of manufacturing by sol-gel method, of spherical SiO2 particles containing nanoparticles of metal (inter alia Ag, Zn) oxides, introduced in the process of hydrothermal dispersing, consisting in stirring for several hours in a pressurized autoclave, at the temperature 185-200° C., the aqueous suspension of silica and metal oxides. The grain size of obtained powders is in the range of 1 to 200 μm. The described process does not solve the problem of obtaining silica nanopowders with the size below 200 nm, containing metal nanoparticles. It may lead to several restrictions connected with their use as nanofillers, e.g. in polymer composites.
BACKGROUND
The properties of polymer nanocomposites connected with the size of nanofiller particles are quite different from the properties of composites obtained with fillers with particles of the size above 200 nm. The use of just small amount of the nanofiller in polymer nanocomposites of an order of 0.5-6% permits to improve the mechanical, optical and barrier properties as well as higher chemical and thermal resistance. The coefficient of linear expansion and flammability decrease, which is advantageous for the final product. These results cannot be obtained with the use of standard amounts of the filler (ca. some dozen percent based on the whole composite).
SUMMARY
Method of manufacturing the silica nanopowders with fungicidal properties, by the sol-gel method of the invention is characterized in that the silica sol containing immobilized nanometric copper particles is prepared from the aqueous reaction mixture containing tetraalkoxysilane, in which the alkoxy group contains from C1 to C4 carbon atoms, alcohol or a mixture of aliphatic C1 to C4 alcohols in a mol ratio of from 1:5 to 1:35, in the presence of ammonium compound, used in an amount of from 0.001 to 0.05 mol per 1 mol of tetraalkoxysilane, by introducing, after the thorough mixing of components, the thermodegradable copper(II) salt in the form of aqueous solution in an amount of 0.0015-0.095 mol per 1 mol of tetraalkoxysilane, and with the addition of a compound from the group of carbo-functional alkoxysilanes, in an amount of 0.015-1 mol per 1 mol of copper(II) salt, and thereafter, after thorough mixing and the evaporation of solvents the dry residue is heated at the decomposition temperature of copper(II) salt.
Preferably, tetramethylammonium hydroxide or tetraethylammonium hydroxide is used as an ammonium compound.
Preferably, copper(II) acetate or copper(II) formate is used as copper(II) salt.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 represents the X-ray dispersive spectroscopy (EDS-energy dispersive spectroscopy) pattern for silica nanopowders containing immobilized nanometric copper particles.
Preferably, γ-aminopropyltriethoxysilane or γ-glycidoxypropyltriethoxysilane is used as a compound from the group of carbo-functional alkoxysilanes.
DETAILED DESCRIPTION
The size of nanometric copper particles deposited by the process of the invention on the surface of nanopowder particles does not exceed 50 nm. Silica nanopowder containing immobilized copper particles of the process of the invention, of the particle size 48 nm are characterized with bulk density 86 g/l, and the bulk density of unmodified nanosilica of analogous particle size is 49.1 g/l (according to PE-EN 1097-3:2000).
Silica nanopowders containing immobilized copper nanoparticles are characterized with biocidal activity, as it was show on the basis of microbiological tests by growth medium method on fluid media, performed in conditions of free access to nutritious substances. It was found that silica nanopowders containing immobilized nanometric copper particles show biocidal activity against mold fungi with the dose of 1.2 ppm. Non-modified silica nanopowders do not show fungicidal activity.
Silica nanopowders containing immobilized copper nanoparticles, obtained by the process of the invention, are storage stable, and the size of nanometric copper particles does not change.
The properties of obtained by the method of invention silica nanopowders, containing immobilized nanometric copper particles are important in the use of such powders as components of polymer composites, used in conditions favoring growth of fungi and molds. These may be, for example, composites containing cellulose fibers designed for the production wood-like moldings or packaging materials. Silica nanopowders, containing immobilized nanometric copper particles obtained by the method of invention can be used as additives for paints, varnishes, points used in rooms of higher hygienic requirements. They prevent the growth of mold fungi in moistened compartments: Aspergillus fumigatus, Aspergillus ustus, Aspergillus sydowii, Penicllium verrucosum, Paecilomyces lilaceum as well as bacteria of the genus Pseudomonas, Bacillus and the individual strains of Alcaligenes faecalis, Staphylococcus xylosus, Aerococcus viridans, Acinetobacter juni/johnsoni, Achromobacter xyloxidans, Brevundimonas vesicularis, Stenotorphomonas maltophilia, Gemella haemolysans.
The manufacturing of silica nanopowders containing nanometric copper particles on the surface, by the method of invention is illustrated in examples.
EXAMPLE I
160.1 g (3.47 mol) of anhydrous ethanol, 1.2 g of 25% aqueous solution of tetraethylammonium hydroxide (0.002 mol) and 55.2 g of distilled water was stirred by magnetic stirrer in an Erlenmeyer flask. The pH of the obtained mixture was 11.11. Subsequently, 21.3 g (0.10 mol) tetraalkoxysilane was added to the reaction mixture. In an early stage the reaction mixture was clear, but after 50 min the opalescence of the solution was observed. The contents of the flask was kept at ambient temperature and stirred for 2.5 h. On the basis of the analysis of obtained sol by photon correlation spectroscopy it was found that the size of sol particles was 50-56 nm. After 24 h 2.4 g of aqueous 0.1 mol solution of copper(II) acetate (0.00024 mol) and 0.00489 g γ-glycidoxypropyltriethoxysilane (0.000019 mol) were added to the reaction mixture. The whole mixture was stirred for 1 h. Thereafter the product was dried in the oven at the temperature of 90° C. for 1.5 h and heated at 250° C. for 2 h to decompose the copper acetate.
FIG. 1 presents the X-ray dispersive spectroscopy (EDS-energy dispersive spectroscopy) pattern permitting to perform the qualitative and quantitative analysis of the contents of metals, with visible peaks characteristic for copper.
The contents of copper, determined by atomic absorption spectroscopy was 0.0032 wt. %.
The so obtained silica powder, containing immobilized copper particles, was added in an amount of 5 wt. % to the polymer composite based on polycarbonate. On the basis of performed microbiological tests it was found that the obtained polymer composite containing 0.00016 wt. % (1.6 ppm) of copper nanoparticles immobilized on silica nanopowder had a biocidal activity against fungi Aspergillus fumigatus, Aspergillus ustus, Aspergillus sydowii.
EXAMPLE II
160.1 g (3.47 mol) of anhydrous ethanol, 0.47 g of 25% aqueous solution of tetraethylammonium hydroxide (0.002 mol) and 55.2 g of distilled water was stirred by magnetic stirrer in an Erlenmeyer flask. The pH of the obtained mixture was 11.39. Subsequently, 21.3 g (0.10 mol) tetraalkoxysilane was added to the reaction mixture. In an early stage, the reaction mixture was clear, but after 50 min the opalescence of the solution was observed. The contents of the flask was kept at ambient temperature and stirred for 2.5 h. On the basis of the analysis of obtained sol by photon correlation spectroscopy it was found that the size of sol particles was 75-80 nm. After 24 h 6.8 g of aqueous 0.1 mol solution of copper(II) formate (0.00069 mol) and 0.0106 g γ-aminopropyltriethoxysilane (0.000048 mol) were added to the reaction mixture. The whole mixture was stirred for 1 h. Thereafter, the product was dried in the oven at the temperature of 90° C. for 1.5 h and heated at 280° C. for 2 h to decompose the copper formate. The contents of copper, determined by atomic absorption spectroscopy was 0.006 wt. %. It was determined by scanning electron microscopy, that the obtained nanopowder consists of silica particles with the size of approximately 80 nm, containing immobilized copper nanoparticles.
The so obtained silica powder, containing immobilized copper particles, was added in an amount of 3 wt. % to the polymer composite based on polypropylene. On the basis of performed microbiological tests it was found that the obtained polymer composite containing 0.00025 wt. % (2.5 ppm) of copper nanoparticles immobilized on silica nanopowder had a biocidal activity against fungi Penicllium verrucosum, Paecilomyces lilaceum.
EXAMPLE III
160.1 g (3.47 mol) of anhydrous ethanol, 1.77 g of 25% aqueous solution of tetraethylammonium hydroxide (0.002 mol) and 55.2 g of distilled water was stirred by magnetic stirrer in an Erlenmeyer flask. The pH of the obtained mixture was 11.51. Subsequently, 21.3 g (0.10 mol) tetraalkoxysilane was added to the reaction mixture. In an early stage the reaction mixture was clear, but after 50 min the opalescence of the solution was observed. The contents of the flask was kept at ambient temperature and stirred for 2.5 h. On the basis of the analysis of obtained sol by photon correlation spectroscopy it was found that the size of sol particles was 100-120 nm. After 24 h 70.0 g of aqueous 0.1 mol solution of copper(II) acetate (0.007 mol) and 0.1397 g γ-aminopropyltriethoxysilane (0.00063 mol). The whole mixture was stirred for 1 h. Thereafter the product was dried in the oven at the temperature of 90° C. for 1.5 h and heated at 250° C. for 2 h to decompose the copper acetate. The contents of copper, determined by atomic absorption spectroscopy was 3.9 wt. %.
The so obtained silica powder, containing immobilized copper particles, was added in an amount of 0.3 wt. % to the polymer composite based on polyethylene. On the basis of performed microbiological tests it was found that the obtained polymer composite containing 0.00792 wt. % (79.2 ppm) copper nanoparticles immobilized on silica nanopowder had a biocidal activity against fungi Penicllium verrucosum, Paecilomyces lilaceum, Aspergillus fumigatus, Aspergillus ustus, Aspergillus sydowii.
EXAMPLE IV
189.23 g (4.10 mol) of anhydrous ethanol, 0.06 g 25% aqueous solution ammonia (0.0004 mol) and 48.75 g of distilled water was stirred by magnetic stirrer in an Erlenmeyer flask. The pH of the obtained mixture was 11.54. Subsequently, 28.2 g (0.13 mol) tetraalkoxysilane was added to the reaction mixture. In an early stage, the reaction mixture was clear, but after 13 min the opalescence of the solution was observed. The contents of the flask was kept at ambient temperature and stirred for 2.5 h. On the basis of the analysis of obtained sol by photon correlation spectroscopy, it was found that the size of sol particles was 180-190 nm After 24 h 73.0 g of aqueous 0.1 mol solution of copper(II) acetate (0.0073 mol) and 0.1457 g γ-glycidoxypropyltriethoxysilane (0.00058 mol). The whole mixture was stirred for 1 h. Thereafter, the product was dried in the oven at the temperature of 90° C. for 1.5 h and heated at 250° C. for 2 h to decompose the copper acetate. The contents of copper, determined by atomic absorption spectroscopy was 4.5 wt. %.
The so obtained silica powder, containing immobilized copper particles, was added in an amount of 1.5 wt. % to the polymer composite based on polyamide 6. On the basis of performed microbiological tests it was found that the obtained polymer composite containing 0.07 wt. % (700 ppm) copper nanoparticles immobilized on silica nanopowder had a biocidal activity against fungi Penicllium verrucosum, Paecilomyces lilaceum, Aspergillus fumigatus, Aspergillus ustus, Aspergillus sydowii.
EXAMPLE V
156.2 g (3.39 mol) of anhydrous ethanol, 0.5 g 25% aqueous solution ammonia (0.0036 mol) and 36.8 g of distilled water was stirred by magnetic stirrer in an Erlenmeyer flask. The pH of the obtained mixture was 11.49. Subsequently, 20.03 g (0.09 mol) tetraalkoxysilane was added to the reaction mixture. In an early stage the reaction mixture was clear, but after 25 min the opalescence of the solution was observed. The contents of the flask was kept at ambient temperature and stirred for 2.5 h. On the basis of the analysis of obtained sol by photon correlation spectroscopy, it was found that the size of sol particles was 140-160 nm After 24 h, 77.0 g of aqueous 0.1 mol solution of copper(II) acetate (0.008 mol) and 1.597 g γ-aminopropyltriethoxysilane (0.0072 mol). The whole mixture was stirred for 1 h. Thereafter, the product was dried in the oven at the temperature of 90° C. for 1.5 h and heated at 250° C. for 2 h to decompose the copper acetate. The contents of copper, determined by atomic absorption spectroscopy was 3.5 wt. %.
The so obtained silica powder, containing immobilized copper particles, was added in an amount of 0.75 wt. % to the polymer composite based on polyethylene terephthalate. On the basis of performed microbiological tests it was found that the obtained polymer composite containing 0.09 wt. % (900 ppm) copper nanoparticles immobilized on silica nanopowder had a biocidal activity against fungi Penicllium verrucosum, Paecilomyces lilaceum, Aspergillus fumigatus, Aspergillus ustus, Aspergillus sydowii. | Method of manufacturing the silica nanopowders with fungicidal properties, consists in that the silica gel is obtained by sol-gel method from the reaction mixture containing tetraalkoxysilane and aliphatic alcohol, in the presence of ammonium compound, and thereafter the thermodegradable copper(II) salt a compound from the group of carbofunctional alkoxysilanes, and then, after evaporation of solvents the dry residue is heated at the decomposition temperature of copper(II) salt. | 0 |
The present invention relates to a system comprising a pipe network, partly arranged underground and partly airsuspended and designed to feed and distribute water or liquid fertilizers. In the following description reference is made only to a water distribution system. From predetermined points of the network vertical tubes are branched off, each designed to feed at least one distribution tube, which hereinafter will be called "water tube" and which is made of rigid plastics as, for instance, polyvinyl chloride or polyethylene. Each of the water tubes is substantially horizontal and is carried by suitable supports. At predetermined positions along each of the water tubes distribution boxes are mounted hereinafter referred to as "derivation boxes or cases" which feed a plurality of hanging water distribution pipes, called "delivery pipes" of differing lengths and which can be extended with additional pipe sections and sleeve joints. The delivery pipes are mounted at convenient positions and they are uniformly spaced from each other in such a manner that the water and the like can fall onto the ground so as to maintain a correct degree of moisture for the plant roots.
In general each horizontal water tube extends along a row of trees and each derivation case is positioned near a plant so that the hanging flexible distribution pipes are sufficiently spaced from the branches of the plant so that they can depend towards the ground. For fields under herbaceous cultivations or inside glasshouses, the water tubes are positioned at a height over the ground level of from 3 to 5 m, and the derivation cases are mounted thereon at a mutual distance of about 4-5 m.
The mutual spacing of the flexible delivery pipes are obtained by the use of small ropes of plastics. On account of the fact that the water is distributed from the top, the required water pressure into the water tubes is low and can be of the order of a half atmosphere. In the cases of very calcareous waters it is necessary to use, at suitable time intervals, higher pressures to cleanse and remove deposits which may form. In the event the used liquids are contaminated it will be necessary to first decant or filter them.
Drop irrigation systems are already known in which tubes are used which are disposed above or below ground and along which drop distribution means are provided which allow the liquid to be dispensed in drops.
Such systems have the inconvenience that they interfere with the use of agricultural machines since they can obstruct their passage. In contrast thereto, the irrigation system of this invention performs a distribution of the liquid from above so that broad ground bands remain entirely free to thereby permit the use of tractors or other agricultural machines. The invention for the water distribution provides to use small hanging pipes made of black, slightly flexible plastics having an inner diameter of 1-2 mm, thus avoiding the use of pipes of smaller diameter which could be easily obstructed by deposits of the solids suspended in the liquid or by algae which can be present, even if filters are used for purification purposes. These small pipes are of a dark color for the purpose of preventing light from promoting the growth of algae in the inside of said pipes.
Said small flexible pipes which pass through the tree leaves and those which pass among the herbaceus plants from water drops of fine water streams which fall onto the ground so that said water can seep very slowly through the ground, thereby maintaining the roots moist and without wetting the leaves. Of course, simple pipes are used which assure a free water delivery, prevent the formation of any obstruction in the pipe.
These and other characteristics of the present invention will be better understood from the following specification of an embodiment of this invention, shown in the accompanying drawings, in which:
FIG. 1 is a diagrammatic partial view of several tree rows, said view being taken in a vertical plane parallel to the secondary feeding tubes from which vertical distribution tubes are branched off;
FIG. 2 is an enlarged detail, in section, and is taken along the line A--A of FIG. 1 at a right angle to a distribution pipe and shows a tree adjacent to a water feeding tube, a distribution case and other pertinent parts of the irrigation system;
FIG. 3 shows a front view of the right half and a section of the left half of a distribution box or case constructed, according to a first variant of the system for the connection of said box with a distribution pipe made of rigid plastics;
FIG. 4 is a longitudinal side view of a detail of the portion of the rigid pipe, shown in FIG. 3 where the connection means are provided and which includes positioning means and a hole through which the liquid flows out; and
FIG. 5 is a view, partially in section, of the lower portion of a distribution box constructed according to a variant designed to be used for the connection of a flexible distribution pipe, made of polyethylene, for instance.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Now referring to the drawings, there are main feeding tubes 1 and secondary feeding tubes 2, set at right angles and placed underground, said main and secondary tubes 1 and 2 already being often present in several agricultural fields for conveying the water to conventional sprinklers. Of course, nothing prevents that in new system said main tubes 1 and secondary tubes 2 can be constructed underground or according to an air-disposition. The secondary tubes 2 in general are set at right angles to the tree rows. Each tube 2 is branched off from a main tube 1 by means of a pipe connector 3, and by means of T-connectors 4 two or more vertical tubes 5 are connected to a tube 2, said vertical tubes being made of plastics as for instance, polyvinyl chloride. Each tube 5 can be of a diameter of one inch and of a height above ground of about 100-130 cm, said tubes 5 have threaded end portions. In the event that no centralized filtering apparatus is provided, a filtering box 6 is removably mounted to each vertical tube 5. The filtering box prevents the passage of algae or solid impurities, which might be transported in the liquid to be distributed which can be water or also a liquid containing fertilizers.
A second tube section 5a is connected, to the upper portion of the box 6. Section 5a has a diameter about half the diameter of the tube 5 and a height of about 100-350 cm. On the upper end of tube section 5a is a T-connector 8 for the connection of a water distribution tube 9 extending along the tree row.
For a good operation of the system on each plot of land, it is advisable that all connector pipes 8 be placed at the same elevation from the ground at a distance of about 2.5 to 5 m therefrom so as to allow the tractor to be freely driven between two adjacent tree rows.
Adjacent each tube 5,5a and optionally also at intermediate points strong stakes or posts 7 are placed. These posts may be made of wood, reinforced concrete or the like and they carry the horizontal water distribution tube 9 and the distribution boxes or cases 11.
Each stake 7 has a height greater than that of the respective tube 9 and is provided with suitable struts. The tubes 9 are made of plastics, as, for instance, rigid polyvinyl chloride or polyethylene of a slightly flexible type and they must be adapted to withstand to a pressue of at least 6 atmospheres.
They have an outer diameter of about 20 mm and a thickness not less than about 1.4 mm. The tubes 9 are fastened by suitable means to the vertical stakes 7 which could be also all or only in part substituted by taut steel cables mounted at a height of about 3 to 5 m above the ground level so as to obtain a pergola-like carrying structure. The end portions of the tubes 9 are inserted in the pipe connectors 8 and they should also be supported at intermediate points so that their span between two adjacent pipe connectors 8 forms a catenary which is slightly concave near its center so as to promote the flow of the water towards said central zone. One or more of distribution boxes 11 or derivation cases are mounted in vicinity of each tree, or they are spaced from each other a distance of about 4-6 meters for vegetables or fodder plants having short stems.
The derivation cases 11 are preferably mounted on top of tubes 9 at an elevation of 2 to 5 m above the ground along a row of plants and at a distance substantially equal to that of the plant rows or, in absence of the latter they are spaced from each other a distance of about 5 to 7 m.
According to the variant shown in FIGS. 3 and 4, the tube 9 is of a rigid type and in register with the vertical axis of each distribution case 11. Tube 9 is provided with a small hole 10 of a diameter of about 2.5 mm at each location where a box 11 is to be mounted. A saddle-like element 12 made of polyvinyl chloride or the like and having a large central orifice 13 in register with the axis of the hole 10 is bonded to tube 9. Element 12 houses a packing ring 14 made of rubber. Two small pins 15 extend upwardly from element 12. They are provided for a correct positioning of the derivation case 11 on the tube 9 in register with the hole 10. The cases 11 are substantially identical in both of the embodiments shown in FIGS. 3, 4 and 5; only the connection system varies slightly depending on whether a rigid pipe 9 (FIGS. 3 and 4) or a semirigid pipe 9a (FIG. 5) is used.
The derivation box or case 11 is preferably made of nylon and comprises a hollow body 16 provided with an inner threaded portion near its upper open end, formed to receive a plug having an externally threaded portion and adapted to seal the box-like body 16.
Two superposed, cylindrical, coaxial chambers 18 and 20 formed in body 16 beneath the thread which engages plug 17. The upper chamber 18 has a greater diameter and a peripheral wall provided with a plurality of radial slots 19 while the lower chamber 20 has a lesser diameter so as to define an inner annular shoulder 21. A rubber ring 22 is placed on shoulder 21. A plurality of radial holes 23 of a number which is less or equal to the member of the slots 19 extend through the ring and the ring has a radial extent substantially equal to that of the shoulder 21 on which said ring 22 is mounted so that the chamber 20 can be put in communication with the outside only through the holes 23 and through slots 19 which are in register with the holes 19 of the ring 22. Of course, the holes 23 of the ring 22 are angularly spaced from each other a distance equal to or a multiple of the spacing of the slots 19. Provision should be made to have available a series of rings 22, each ring having different number of holes 23 so as to be able to obtain a distribution box 11 with the desired number of water distribution pipes 32.
A filtering disc 24 made of nylon is removably mounted beneath ring, said chamber 20 extending downwardly with an axial duct 26 projecting outwards with a short pipe length 27 designed to enter the orifice of the packing ring 14. Underneath and about the pipe 27 the lower part of the box 16 forms a saddle like recess 28 designed to sealingly receive the upper portion of the tube 9 placed underneath the saddle like element 12. At both sides of the saddle recess 28 the lower portion of the body 16 forms two brackets 29 having lower flat surfaces 29a through which threaded holes 30 extend. The holes are arranged to receive locking screws 31 for tightly bolting a semicollar 42 against the brackets 29 in order to put in communication the hole 10 with the overlying distribution case 11.
Through the slots 19 and the holes 23 of the ring 22 will be inserted water distribution pipes 32 which are made of dark polyvinyl chloride or polyethylene; additional lengths of extension pipes 33 can be connected to pipes 32 with small sleeves of plastics 34.
The embodiment shown in FIG. 5 is substantially identical to the preceding one, except that the pipe 9a is made of slightly flexible polyethylene. In the tube 9a there is a hole 10a having an outer diameter of 5.5 mm, slightly less than the outer diameter of a union 27a which can be forced into the hole 10a. A packing washer 36 of rubber is provided to assure a water tight connection. All the other parts are identical and are indicated with the same reference numerals as are used in the embodiment of FIGS. 3 and 4.
This variant is more adapted to be used in glasshouses or where there is a supporting framework so that slightly flexible water distribution tubes 9a can be used which are less rigid than the tubes 9.
The small pipes 32, 33 are arranged to pass through the leaves of the trees between the bifurcations of the branches of the trees which serve to support and to guide said small pipes 32, 33 in whatever direction is derived. The pipes have open ends facing the ground at a distance above the ground of about 40 cm. Since said pipes 32 and 33 are of a flexible type, they cannot hinder the movement of tractors, machines, ladder transfer or the means for fruit or vegetable picking. In the case of fodder or vegetable cultivation in an open field, several or all the pipes 32 can be extended downwardly through connection sleeves 34 by additional lengths of pipes 33; at least some of them can be sufficiently long so that their open ends are inserted into the ground. By uniformly spacing the pipes 33 from each other, for example by means of a rope network arranged parallel to the ground a uniform distribution of water can be attained and water drops can reach the root system of each plant thereby to provide an appropriate irrigation and fertilization thereof. In cases in which the water to be distributed contains fertilizers which must directly reach the root systems such an arrangement assures that the water and fertilizer are appropriately fed to the roots. | An irrigation system for trees, vegetables, fodder plants and the like having a feeding network including main and secondary liquid distribution pipes, vertical pipes branched off the distribution pipes and conneted to substantially horizontal distribution tubes located above ground. Each such tube extends along a row of trees, or, in absence of trees, at predetermined mutual equal distances from other tubes. Each horizontal tube mounts liquid distribution cases, each positioned near a tree or, in absence of trees, at predetermined mutual distances. Each distribution case is provided with a plurality of peripheral radial slots through which pass a variable number of small slightly flexible, downwardly depending tubes made of dark plastic. At least some of the small tubes have their outlet orifices placed at a predetermined distance above the ground. | 0 |
BACKGROUND OF THE INVENTION
The invention relates to the use of ethylene-co-vinyl acetate (EVA) for the manufacture of outer soles of shoes. The vinyl acetate content of the polymer material used is 14 to 28% and materials of this type are distinguished by especially high flexibility, low weight, good wear behavior and ability to be dyed.
In German Offenlegungsschrift No. 16 85 383, a method for the manufacture of a profiled sole of elastomer with a pore structure is described, in which a quantity of the elastomer mixture corresponding to the size of the sole is placed in the sole mold which during this process is larger than the volume of the finished sole. The elastomer mixture is subsequently distributed uniformly in the hollow mold by raising a bottom plunger and is foamed to the final dimension during the subsequent slow lowering of the bottom plunger. The finished sole can then be taken from the hollow mold and is characterized by the finely developed uniform pore structure. The mentioned method nevertheless has found no acceptance because the sequence of the individual operations is time-consuming and precludes mass production at low cost. Corresponding use with repect to the manufacture of a profiled outer sole of EVA is not possible for this reason.
In Austrian Patent Application No. 67 57/78, a method for the manufacture of a molded shoe part with a relief-like structured surface of a cross-linked polyolefin foamed with closed cells is described. For this purpose a foam material blank with specific dimensions is first formed from the material used and then formed in the desired manner into a mold through the use of a combined heat-pressure treatment. This results in heavy densification of the foam material blank over the entire cross section, and as a consequence, in an increase of the specific gravity and an impairment of the flexibility. The pore size and distribution vary extremely as a function of the degree of densification, which is detrimental with respect to the wear behavior. For this reason, an outer sole cannot be made in this manner. The processing of EVA is not mentioned in the cited literature reference.
It is, therefore, an object of the invention to develop an efficient method for the mass production of a profiled outer sole of a cross-linked EVA foamed with closed cells, which ensures the achievement of a homogeneous and uniformly fine pore structure. Such soles are commonly known as waffle soles, "Vibram"® soles and other similar types with lugs, ridges or other gripping features on the bottom of the sole. It is desired thereby to achieve the manufacture of an outer sole which is distinguished by high flexibility with low weight and good wear behavior.
SUMMARY OF THE INVENTION
According to the invention, there has been developed a method for manufacturing a relief-like profile outer sole of cross-linked EVA foamed with closed cells. The method comprises foaming and crosslinking the EVA into a sole blank, tempering the blank, splitting it horizontally into subblanks by at least one cut, heating the surfaces of a subblank to a temperature of from about 120° C. to about 200° C. wherein the temperature at the depth of the relief profile does not exceed 75° C., and pressing the heated surfaces with a molding plunger heated to about 65° C. to 80° C. to produce a relief profile blank which can be shaped and sized to form an outer sole.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram illustrating the various sequential steps of a process according to the present invention, with particular reference to the processes set forth in Examples I and II;
FIG. 2 is a schematic representation of the horizontal splitting of a sole blank into two subblanks utilizing a cutting knife;
FIG. 3 is a schematic representation of the heating of a subblank using infrared radiators; and
FIG. 4 is a schematic representation of the heated subblank preparatory to formation of a relief profile on both surfaces thereof using molding elements with appropriately shaped relief structure.
DETAILED DESCRIPTION OF THE INVENTION
Contrary to known methods, the method of the invention makes it possible to structure in relief-fashion, i.e., with lugs, ridges, waffles or similar raised surfaces, without appreciably increasing the specific gravity. This preserves the original homogeneous and uniformly fine pore structure which is of particular advantage with respect to the use properties of an outer sole for footwear.
The necessary sole blanks of cross-linked EVA foamed with closed cells can be formed and vulcanized in the customary platen presses. By uniformly mixing-in an expansion agent with a decomposition point below the vulcanizing temperature, a spontaneous increase of the volume to about three times the original volume is obtained while developing the desired fine pore structure. The surfaces are smooth and flat and it is therefore not necessary to rework them additionally by removal of material prior to further processing. Due to the closed pore structure, the surfaces are completely closed in themselves. The pore diameter varies between 30 and 100 μm, with an average of 60 μm.
By mechanically splitting the sole blank into several blanks, the basically closed pores arranged in this region are opened and a velvet-like appearance results, which differs distinctly from that of the surfaces facing the plates of the press during the vulcanizing operation. However, this change is not accompanied by a detrimental change of the mechanical properties and it is therefore possible to sort the subblanks by fashion or style aspects. This, of course, does not preclude equalizing the appearance of the surfaces by additional grinding or coating with elastomer materials if desired.
In order to accomplish properly the subsequent relief profiling step, it is necessary to heat the blanks or subblanks so that the claimed temperature gradient is preserved over the range of the later profile depth. This can be realized most simply by using a high-energy infrared radiator. The heated subblanks are then plunger pressed with a molding tool to form the relief profile. The cycle time for the subsequent profiling of the surface with a molding tool is relatively short and is only a few seconds. Appreciable rebound of the impressed profile after the pressure plunger was removed is not observed and from the resulting profiled subblanks, outer soles of the desired shape and size can be stamped, using customary processes.
It is also possible to profile both surfaces of the subblanks, using an appropriate method, for instance, in order to obtain better adhesion during the cementing to the inner sole. In general, however, such a procedure is not necessary, and profiling of the walking surface on one side is sufficient.
In the following examples, the present invention will be explained in greater detail.
EXAMPLE 1
The components given in the following table were placed in an internal mixer and were mixed for about eight minutes at a temperature of 120° C. to form a homogeneous mass. The data in percent refer to the respective content of the individual components in the total weight of the finished product:
______________________________________Ethylene-co-vinyl acetate with a vinyl acetate 60%content of 20%Silica, precipitated 17Calcium carbonate, coated 13Zinc soap of a fatty acid as a processing aid 2.5Azodicarbonamide as a foaming ageent 1.7Iron oxide pigment as the coloring agent 5.4______________________________________
After complete homogenization, the foregoing mixture was taken from the internal mixer and was further processed in a friction mill at a temperature of 70° C. The composition was completed by the addition of 0.4% by weight of an α,α'-bis-(t-butylperoxy)--diisopropylbenzene as a cross-linking agent to 100%.
The preliminary product obtained was formed into an uncross-linked, sheet 2.3 cm thick with a length of 82 cm and a width of 58 cm. The size corresponded exactly to the size of the cavity of the blank molding tool which was preheated to a temperature of 170° and into which the sheet was subsequently placed. The tool was closed immediately and a pressure of at least 70 kg/cm 2 was applied. The sheet contained therein was heated-through for 15 minutes at the indicated temperature. This brought about the vulcanization and activated the expansion agent contained in the sheet.
At the end of the indicated time the tool was opened and the expansion agent, decomposed by the action of the mentioned temperature, had made the sheet expand into a sole blank of 120×85 cm with a thickness of 3.4 cm. The blank was placed in a tempering oven heated to a temperature of 80° C. and was fully vulcanized during a period of 6 hours. The specific gravity was 0.35 g/cm 3 after cooling down.
The blank (element 1 of FIG. 2) obtained in this manner was subsequently cut apart into the subblanks 2 and 3, each of which was 6 mm thick by means of a belt knife 4. From one such subblank 2 an outline 5 with a size of 30×20 cm was stamped out and irradiated by means of an infrared black-light radiator 8 for a period of 2.5 seconds with a power of 6.5 W/cm 2 . At the surface, a temperature of 130° C. was obtained, and at a depth of 3 mm below the surface, a temperature of 70° C.
The blank warmed up in this manner was immediately transferred into a relief-profile forming plunger press tool and given a surface profile. The tool plunger (6,7 of FIG. 4) used consisted of steel which had been heated to a temperature of 80° C. The profile consisted of columnar recesses, arranged at a mutual distance of 12 mm, with a diameter of 5 mm and a depth of 3 mm.
A pressure of 6 kg/cm 2 was used with a dwelling time of the blank in the plunger tool of 10 seconds. The surface was formed in the process in accordance with the shape of the plunger tool and was distinguished by especially good contour sharpness. After cooling, the specific gravity was 0.37 g/cm 3 and thus was nearly unchanged.
EXAMPLE II
The procedure described under Example I was repeated, using a plunger press tool with a plunger surface structured in relief-fashion of recesses in the shape of truncated pyramids. The recesses were immediately adjoining and had a depth of 3 mm with a side length of 4 mm. Also this molding pattern was transferred with sharp contours on the loaded-in blank. The specific gravity was 0.36 g/cm 3 and was therefore almost unchanged. The pore structure was distinguished by nearly unchanged excellent homogeneity.
EXAMPLE III
A Comparative Sole made from a Uniformly Heated Blank
A blank with a size 30×20 cm according to Example I was placed into a heating chamber for generating a special temperature gradient and was heated up there to a temperature of 130° C. equalized over the entire cross section, i.e., the internal temperature of the blank was the same as the external temperature. The sheet was subsequently transferred to the plunger press tool and structured at the surface, using the press tool described in Example I and by applying the same conditions. The pattern obtained had by poor contour sharpness and the specific gravity had risen to the undesirably value of 0.56 g/cm 3 . The flexibility and the wear behavior also did not meet the requirements demanded of a good outer sole material. | Method for the manufacture of a relief profiled outer sole of cross-linked EVA polymer foamed with closed cells is described in which the polymer used is formed into a cross-linked, expanded tempered blank, split by at least one cut into several subblanks, and whereupon the surface of a subblank is heated and pressed to form the relief profile. The temperature gradient of the blank while it is being pressed is important for precise formation of the relief profile. | 1 |
This is a continuation of application Ser. No. 08/292,857 filed on Aug. 19, 1994, now abandoned.
BACKGROUND OF INVENTION
This invention relates to an assembly for sharpening blades and more particularly to such an assembly of the type including a blade holding device and a sharpening member cooperable with the blade holding device for guiding a sharpening stone of the sharpening member across an edge of a blade held by the holding device.
In the prior art, there has been developed a type of blade sharpening assembly which basically includes a blade holding device and a sharpening member cooperable with the holding device to sharpen an edge of a blade held by the holding device. The holding device typically has consisted of a pair of blade holding members or jaws pivotally connected together at a fulcrum point, means for angularly displacing one set of ends of the blade holding members about the fulcrum point to correspondingly angularly displace an opposite set of ends of such holding members for clamping a blade therebetween, and a guide post usually connected to or formed integrally with one of the blade holding members, provided with a plurality of spaced openings. The sharpening member typically has consisted of a gripping portion having a sharpening stone disposed on an underside thereof and engageable with an edge of a blade held by the blade holding members, when in use, and a longitudinally disposed rod portion adapted to be received in a selected opening of the guide post for guiding the sharpening member as the sharpening stone portion thereof is moved in a reciprocating motion across the blade edge. Examples of such type of blade sharpening device are disclosed in U.S. Pat. Nos. 4,320,892 and 4,486,982 to Howard F. Longbrake, U.S. Pat. Nos. 4,512,112, 4,714,239 and 4,777,770 to Arthur L. LeVine and U.S. Pat. No. 5,138,801 to John R. Anthon et al.
In each of such type of blade holding device, it has been found that the design thereof has been unduly complicated resulting in high manufacturing costs, awkward and difficult assembly and disassembly of the components of the device and unsatisfactory use of the device. It thus has further been found to be desirable to provide an improved blade sharpening device of the type described, obviating the various design flaws attendant to prior art blade sharpening devices.
Accordingly, it is the principal object of the present invention to provide an improved assembly for sharpening blades.
Another object of the present invention is to provide a blade sharpening assembly of the type utilizing a blade holding device provided with a guide post and a sharpening device provided with a gripping portion, a sharpening stone disposed on an underside of the gripping portion thereof and engageable with an edge of a blade held by the blade holding assembly, and a longitudinally disposed rod portion receivable within a selected opening of the guide post for guiding the sharpening member as the sharpening stone thereof is moved across the edge portion of the blade with a reciprocating motion.
A further object of the present invention is to provide an improved blade sharpening assembly which may be used in either hand held or bench mounted positions.
A still further object of the present invention is to provide an improved blade sharpening assembly which is comparatively simple in design, relatively inexpensive to manufacture, easy to quickly assemble and disassemble and effective in use.
Other objects and advantages of the present invention will become more apparent to those persons having ordinary skill in the art to which the present invention pertains from the following description taken in conjunction with the accompanying drawings wherein:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a blade sharpening assembly embodying the present invention;
FIG. 2 is an enlarged cross-sectional view taken along line 2 — 2 of FIG. 1;
FIG. 3 is an enlarged cross-sectional view taken along line 3 — 3 in FIG. 1;
FIG. 4 is an enlarged perspective view of a portion of the assembly shown in FIG. 1, illustrating several components thereof in exploded relation;
FIG. 5 is a perspective view of a portion of the assembly shown in FIGS. 1 through 3, illustrating the assembly mounted in a fixed position on a support surface; and
FIG. 6 is a side elevational view of a portion of the assembly shown in FIGS. 1 through 4, provided with a clamping device for supporting the assembly on a ledge or overhanging support member of a table or workbench.
DETAILED DESCRIPTION
Referring to FIGS. 1 through 4 of the drawings, there is illustrated a blade holding assembly 10 which generally includes a support member 11 , a blade holding assembly 12 and a sharpening member 13 . The support member includes a hand held base section 14 and a longitudinally disposed guide section 15 . Base section 14 has essentially a cylindrical configuration with a diameter suitable for gripping with an average size hand, and a set of depressions 16 along one side thereof for accommodating the fingers of a hand gripping the member. The base section further is provided with an axially disposed, threaded opening 17 in an end surface 18 to permit the support member and correspondingly the entire assembly to be optionately hand held, or be disposed in a fixed position by mounting the support member on a fixed base member 19 as shown in FIG. 5 or a clamp as shown in FIG. 6 . The base member shown in FIG. 5 is provided with a plurality of screw holes 21 to permit the member to be rigidly secured to a support surface, and an axially disposed threaded stub portion 22 on which the support member may be threaded and thus fixedly supported. C-clamp 20 is of a conventional type adapted to be secured to a ledge or overhang portion of a table or workbench, and is provided with a threaded stub portion 23 onto which the support member may be threaded to secure the support member and correspondingly the entire assembly onto the C-clamp which may be secured to a selected overhanging member.
Base section 14 may be formed of any material although it is preferred to be made of a molded resin such as an acetal resin sold by E.I. Dupont Demours & Co. under the trademark DELPRIN.
Guide section 15 generally consists of an elongated, metallic plate member having an end portion 15 a embedded in the base section so that the guide section projects longitudinally relative to the base section. The guide section further provides an attachment opening 24 disposed adjacent an end surface 25 of the base section, and a plurality of spaced guide slots 26 spaced from opening 24 . As best seen in FIGS. 2 and 4, opening 24 includes a circular portion 24 a and a slotted portion 24 b disposed radially relative to portion 24 a and having a width smaller than the diameter of portion 24 a , resembling a conventional key hole. Guide slots 26 are elongated transversely relative to the length of section 15 and are spaced different distances from opening 24 . Preferably, guide section 15 is formed of a sturdy metallic strip having an irregular end portion 15 a for securely embedding end portion 15 a in base section 14 as shown in FIG. 2 .
Blade holding assembly 12 includes a first blade holding member or jaw 27 , a second blade holding member or jaw 28 and an actuating member 29 . As best shown in FIGS. 3 and 4, blade holding member 27 includes a lower surface 30 having an angularly disposed portion 31 at a forward end thereof, an upper surface 32 having a cut-out portion providing an end surface 33 and an upper surface 34 disposed parallel with surface 30 , a pair of side surfaces and a rear end surface 35 . Such member further is provided with a first threaded opening 36 in upper surface 34 , and a second threaded opening 38 in a recessed portion 37 in upper surface 34 . The member further is provided with a section 39 projecting outwardly from end surface 35 which is adapted to be received through opening 24 in the support member and cooperate with plate section 15 to detachably secure the blade holding assembly to the support member.
As best shown in FIG. 4, projecting section 39 is cylindrically configured and includes a pair of vertically disposed, parallel slots 40 and 41 to provide a head portion 42 and a neck portion 43 . Head portion 42 has a diameter slightly less than the diameter of opening portion 24 a and neck portion 43 has a width slightly less than the width of radially disposed slot 24 b so that head portion 42 may be easily asserted in an axial direction through opening portion 24 a to align neck portion 43 with radial slot 24 b , and the holding assembly may then be displaced downwardly toward base section 14 to insert neck portion 43 in radially disposed slot 24 b . Under such conditions, the blade holding assembly will be detachably connected to the support member and the blade holding assembly will be prevented from becoming detached by reason of the inner sides of head portion 42 engaging outer surfaces of guide portion 15 disposed along the sides of radially disposed slot 24 b . The blade holding assembly will not normally be released from the support member unless the assembly is displaced radially relative to opening portion 24 a to position projecting section 39 axially in opening portion 24 a , and the assembly is displaced axially relative to opening portion 24 a to clear projecting portion 39 from guide section 15 .
Blade holding member 28 is configured to be received within the cut-out portion of holding member 27 and cooperate therewith to receive and clamp a blade to be sharpened between forwardly disposed ends thereof. The member consists of a lower surface 44 adapted to be disposed in opposed relation to upper surface 34 of member 27 , an upper surface 45 disposed parallel to surface 44 and having an angularly disposed forward portion 46 , a pair of side surfaces spaced apart the same distance as the side walls of member 27 and a rear wall 47 adapted to be disposed in opposed relation to surface 33 of member 27 when the blade holding members are in the assembled condition. Blade holding member 28 further is provided with a screw opening 48 adapted to receive a flathead screw 49 therethrough and threaded into opening 36 of member 27 to provide a pivotal connection between members 27 and 28 at a fulcrum point, and a recessed portion 50 in bottom surface 44 provided with an opening 51 adapted to be axially aligned with threaded opening 38 when the blade holding members are in the assembled condition as shown in FIG. 3 .
Actuating member 37 includes a wheel section 52 positioned in recessed portions 37 and 52 and having a diameter slightly greater than the width of the blade holding members, as best shown in FIGS. 1 and 4, and an axially disposed pin 53 having a lower threaded end threaded into threaded opening 38 and an opposite end portion received in aligned opening 51 in blade holding member 28 when the blade holding assembly is in the assembled condition. It will be appreciated that by rotating wheel section 52 , pin 53 will be caused to be displaced axially and correspondingly cause one set of ends to angularly displace relative to the fulcrum point of the assembly and an opposite set of ends of the members to displace to clamp and unclamp a blade positioned therebetween. The blade holding members and the actuating member therefor may be formed of any suitable, sturdy material although it is preferred that they be formed of a metal of suitable strength.
Sharpening member 13 consists of a hand gripping section 54 having a sharpening stone 55 on an underside thereof and engageable with an edge of a blade held between a forwardly disposed set of ends of the blade holding members, and a longitudinally disposed guide rod 56 which is adapted to be received in a guide opening 26 when the assembly is in use as shown in FIG. 1 . The sharpening stone has a generally rectangular configuration, is adhesively or otherwise secured to the underside of gripping section 54 and may consist of any suitable abrasive material for sharpening a blade edge. Guide rod 56 consists of a rigid material, preferably a metal, having an inner end thereof received within a longitudinally disposed opening in gripping section 54 and detachably secured therein by means of a thumb screw 57 .
In the use of the blade holding assembly shown in FIGS. 1 through 4 without the use of a mounting device, the blade holding assembly is grasped in the palm of one hand and wheel 52 may be rotated with the thumb and forefinger to space the set of outer ends of the holding members apart. The blade to be sharpened may then be inserted with the other hand between the spaced apart ends of the holding members and positioned in place while the wheel may be rotated in the opposite direction to clamp the blade between the outer ends of the blade holding members. By holding the support member in one hand and the blade holding assembly with the blade clamped therein in the other hand, the blade holding assembly may be attached to the support member by inserting projecting section 39 into opening portion 24 a of the guide section of the support member, and sliding it downwardly so that neck portion 43 of section 39 is received in radially disposed slot 24 b . With the blade holding assembly thus secured to the support member, the assembly may be released with the one hand and the sharpening member may be grasped and placed in position by inserting guide rod 56 in a guide opening 26 and resting the sharpening stone on the blade edge to be sharpened. Then, while continuing to hold the support member by the base section with one hand, the main body of the sharpening member may be moved with a reciprocating motion forwardly and rearwardly and from side to side to sharpen the blade edge. To adjust the position of the blade relative to the blade holding assembly, it is required only to conveniently grasp and rotate wheel section 52 to displace the set of forward ends of the holding members to release the blade, reposition the blade and then move the holding members together by rotating the wheel in the opposite direction to reclamp the blade in the adjusted position.
In circumstances where it is desired to use the assembly by mounting it on a support structure, the support member may be rigidly mounted on such a support structure by the use of a base member 19 or a clamp assembly 20 . In either instance, the assembly may be used by threading the lower end of the support member onto a threaded stud 22 of the base member or 23 of the C-clamp assembly, attaching the blade holding assembly to the support member as previously described, manipulating the blade holding assembly to position and clamp the blade to be sharpened between the members thereof similarly in the manner as previously described, and then positioning and moving the sharpening member in the manner described to sharpen the blade edge.
The blade sharpening assembly as described provides a number of advantages over various prior art blade sharpening devices. Whenever one side of a blade secured in the clamp assembly has been sharpened and it is desired to sharpen the opposite side of the blade, all that is required to be done to reposition the blade is to slide the clamp assembly upwardly to position projecting section 39 in opening portion 24 a , rotate the clamp assembly 180° to position neck portion 43 of the projecting section in vertical alignment with slot 24 b and lower the clamp assembly so that neck portion 43 again is received within slot 24 b . Such maneuver may be done simply and quickly to accurately position the blade for sharpening the reverse side thereof. Another advantage of the present invention is that when the clamping assembly is in the operative condition as shown in FIGS. 1 through 3, the engagement of neck portion 43 with the side edges of slot 24 b prevents the clamp assembly from rotating about the axis of projecting section 39 . Furthermore, as best illustrated in FIG. 3, when the clamping assembly is mounted on the support member with neck portion 43 of projecting section 39 received within slot 24 b , a portion of lower surface 30 of blade member 27 will be seated on upper surface 25 of the support member to enhance the rigidity and stability of the assembled components when the assembly is in use and a downward force is applied to the clamping assembly as the sharpening member is pressed downwardly onto the blade being sharpened.
The simple design and configuration of each of the several components of the blade sharpening assembly as described permits the positioning of such components in a compact container for storage and other purposes. The components can be arranged and sold in a kit compactly positioned in a case for readily handling and storing such components.
From the foregoing detailed description, it will be evident that there are a number of changes, adaptations and modifications of the present invention which come within the province of those persons having ordinary skill in the art to which the aforementioned invention pertains. However, it is intended that all such variations not departing from the spirit of the invention be considered as within the scope thereof as limited solely by the appended claims. | A blade sharpening assembly generally consisting of a support member having a first opening and at least a second opening spaced from the first opening, a blade holding assembly including a first member having a projecting section receivable in the first opening and cooperable with a portion of the support member for detachably securing the blade holding assembly in supported relation on the support member, a second member pivotally connected to the first member and means for pivoting one of the blade members relative to the other blade member about a fulcrum point to cause opposed end portions of the blade members to converge and engage a blade disposed therebetween in clamping relation, and a sharpening member including a sharpening stone engageable with a blade clamped between the blade holding sections, a longitudinally projecting guide rod receivable within the second opening in the support member and a gripping section which may be gripped to move the sharpening member with a reciprocating motion when the sharpening stone engages the blade and the guide rod is received within the second opening of the support member. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This is a continuation-in-part of application Ser. No. 08/367,009, filed Dec. 30, 1994, now U.S. Pat. No. 5,731,275, the specification of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the invention
The present invention relates to novel synergistic detergent and disinfectant combinations and to an improved method for effectively decontaminating biofilm-coated surfaces. Types of surfaces comprise: the inner surface of aqueous liquid-supplying lines, particularly fresh water lines such as those supplying water to dental instruments regularly used by dentists, dental surgeons or dental hygienists, the inner surface of lines of larger diameters and the inner surface of containers having received aqueous liquids for a sufficient length of time to have allowed growth of microorganisms, their deposition and their organization as a biofilm to adhere to the walls of the containers. More particularly, the present invention relates to detergent-disinfectant combinations for dislodging biofilm formed or accumulated on contaminated surfaces for destroying the microorganisms contained therein. The preferred compositions are particularly suitable for water pipes of dental instruments which are of a small diameter, because no scrubbing is needed for maximal efficiency in a convenient time of decontamination.
2. Brief description of the prior art
Dentists, dental surgeons and dental hygienists and their patients are well aware of the importance of meticulously sterilizing and disinfecting dental instruments. Indeed, since dental instruments are used directly in a patient's mouth, when bleeding may sometimes occur as a result of a dental procedure, it is of paramount importance to minimize the presence of microorganisms carried by dental instruments. The microorganisms can of course range from relatively harmless bacteria to dangerous pathogens. Consequently, efforts are deployed to remove microorganisms from dental instruments and from the fresh water lines feeding dental instruments such as air/water guns, high speed water turbines or ultrasonic tartar removers. For most hand held dental instruments, thermal sterilization remains one of the best methods for eradicating the presence of microorganisms. However, thermal sterilization is obviously not practical for the decontaminating of fresh water lines which remain to this date difficult to rid of microorganisms.
It is well known in the dental profession that small diameter pipes carrying fresh water are contaminated by bacteria and other microorganisms contained in the water flowing through them. Some of the microorganisms inevitably adhere to the inner walls of the pipes and accumulate together with microscopic sediments or other substances into what is commonly known as a biofilm. The biofilm quickly and tenaciously coats the inner walls of the pipes. The biofilm becomes a culture medium for more microorganisms. For example bacteria population will rapidly reach alarming levels which will also be found in the water discharge from the dental instruments connected to the fresh water line. For example, the average bacteria count in the water discharge of dental instruments is known to be of approximately 200,000 colony forming units per milliliter (cfu/ml) and in some extreme cases can reach 10,000,000 cfu/ml.
It has been suggested to use sterile water, to drain the fresh water lines during periods of non-use or to use filters to catch the microorganisms. However, none of those methods have been shown to effectively remedy the microorganism proliferation for any length of time.
It is also known in the art to use disinfectants such as povidone-iodine at a concentration of approximately 10% to reduce the number of microorganisms in small diameter water lines. It is further also known that a mixture of mandelic and lactic acids reduce the number of sensitive microorganisms in contaminated catheters. However, such disinfection is somewhat superficial since it fails to effectively attack and destroy the microorganisms found in the biofilm. Consequently, the disinfection effect is short-lived. After 24 hours of treatment with povidone-iodine, the number of bacteria is greatly reduced but quickly begin to rise after eight days.
It is also known to use a detergent such as polyoxyethylene sorbitan monooleate (Tween 80™) at approximately 4% concentration to dislodge biofilm from small diameter water lines used in dental equipment. However, the use of detergent alone does not effectively destroy the microorganism population.
Accordingly there remains a need for a composition for decontaminating small diameter water lines for dental equipment which will effectively dislodge and eliminate a biofilm and at the same time destroy the microorganism flora in the fresh water and in the dislodged biofilm.
SUMMARY OF THE INVENTION
The invention provides a synergistic cleaning and disinfecting composition for use in decontaminating biofilm-coated surfaces like the fresh water lines providing water supply to dental instruments, these lines being susceptible to contamination by microorganisms and being susceptible to the formation of biofilm coatings on their inner walls, the composition comprising an effective amount of a detergent and of a denaturing agent affecting the integrity of the proteins and of mucopolysaccharides composing the biofilm for dislodging biofilm accumulation on the inner walls of the lines and an effective amount of a bactericide for destroying the microorganisms within the weakened biofilm or retrieved in suspension.
In the preferred embodiment, the detergent is sodium dodecyl sulfate (SDS). This detergent is the prototype of a class of detergents having denaturant as well as detergent action, so that the addition of a denaturing agent is not necessary and the bactericide is either an acid like lactic and mandelic acids or a potent oxidant like hydrogen peroxide (H 2 O 2 ) and hydrogen peroxide-stabilized peracetic acid (PAA), the oxidant being combined with a chelating agent like ethylenediaminetetraacetate (EDTA), or a mixture of both an acid and an oxidant/chelating agent.
It should be understood that the detergent component entering the compositions of the present invention is not limited to SDS or SDS-like detergents. Any detergent able to decrease the surface tension of a biofilm and having a denaturant action or combined with a compound having a denaturant action on components of the biofilm e.g. proteins and mucopolysaccharides, notwithstanding the classification of the detergent as a cationic, anionic or nonionic detergent, is under the scope of this invention.
The invention also provides an improved method for cleaning and disinfecting biofilm-coated surfaces like the fresh water lines providing water supply to dental instruments, the water lines being susceptible to contamination by microorganisms and being susceptible to the formation of biofilm coatings on their inner walls, the steps of:
a) draining the water lines;
b) filling the water lines with the decontaminating solution defined in this invention for destroying the microorganisms retrieved in the weakened biofilm or in suspension;
c) leaving the solution in the water lines at ambient temperature for a period of six hours or more;
d) draining the water lines; and
e) rinsing the water lines.
Of course, if it impossible or non-convenient to drain the water lines, a part of the liquid may be withdrawn and a suitably concentrated composition may be added to bring the proportions of the active ingredients in final appropriate concentrations. Moreover, if flat surfaces are to be decontaminated, the draining step may be omitted and the composition be spread on the surfaces, in conditions such that the composition will retain its decontaminating activity (for example, by avoiding dehydration). Other features and advantages of the invention will become apparent to those of ordinary skill in the art upon review of the following detailed description and claims.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Surprisingly, the inventors have found synergistic compositions for decontaminating microorganism-contaminated water lines having a biofilm coating the inner walls thereof which comprises the following combinations of ingredients:
1) A suitable detergent for reducing the surface tension of the biofilm;
2) A denaturing agent for affecting the integrity of the proteins and of the mucopolysaccharides, which are bacterial cell components or constituents of the extra-cellular matrix (the detergent and denaturing functions are both assigned to a detergent like SDS which has being successfully tried at a 1 to 2% concentration in distilled water); and
3) A suitable bactericidal component composed of one or more bactericides having a wide spectrum. Bactericides like lactic and/or mandelic acids or of a class of potent oxidants like hydrogen peroxide (H 2 O 2 ) and/or hydrogen peroxide-stabilized peracetic acid (PAA) or a mixture of both an oxidant and an acid have been successfully tried. In the case wherein an oxidant is used, the combination denaturing detergent/oxidant needs complementation with a chelating agent like ethylenediaminetetraacetate (EDTA), to achieve maximal efficacy.
Those skilled in the art will readily understand and easily conceive other equivalent synergistic compositions containing effective amounts of other suitable denaturants/detergents or other suitable bactericides dissolved in a suitable carrier.
In a preferred embodiment, it has been found that the combination of a denaturing detergent like sodium dodecyl sulfate (SDS) and of a bactericide like either an acid like lactic and/or mandelic acids or a potent oxidant like hydrogen peroxide (H 2 O 2 ) and/or hydrogen peroxide-stabilized peracetic acid (PAA) (the oxidant being further complemented with a chelating agent like ethylenediaminetetraacetate (EDTA)) has been found advantageous.
A mixture of the following products has been found the most advantageous since its contains:
mandelic acid 1%,
lactic acid 1%,
hydrogen peroxide 5%,
SDS 1-2%, and
EDTA 1%.
This solution may further contain PAA 1% and cetylpyridinium chloride 0.1%.
Even though all these combined elements are very efficient in decontaminating fresh water lines, some subcombinations are equally performant. For instance, combinations of SDS and acids like mandelic and lactic acids, having a pK of 3.36 and 3.79, respectively, destroy a biofilm as efficiently as the above complex formulation. A combination like hydrogen peroxide, SDS and EDTA is also as performant. Another oxidant like peracetic acid is also effective when combined with SDS and EDTA, provided that peracetic acid is stabilized by the presence of hydrogen peroxide. Therefore, it will be appreciated that many combinations will perform as well as the above combinations and subcombinations. The combination of the five compounds listed above is particularly advantageous because it contains bactericides which together attack a wide spectrum of sensitive bacteria. Should a resistant bacterium be discovered in the biofilm, this combination of compounds may be amended to include another effective bactericide or it may be complemented by the adjunction of such another bactericide.
Suitable decontaminant solutions should contain a detergent able to decrease the surface tension of the biofilm, a denaturing ingredient capable of decreasing the cohesive force existing between microorganisms and between the microorganisms and the surfaces, and a bactericide. A compound like SDS has a dual action as a detergent and as a denaturing ingredient decreasing the cohesive force of components of the biofilm. SDS is indeed a denaturing detergent which attacks the integrity of proteins and of mucopolysaccharides. Compounds like hydrogen peroxide and hydrogen peroxide-stabilized peracetic acid also have a dual action as bactericides and potent oxidants which attack the extracellular matrix. Even though lactic acid is not classified as a bactericide, it shown good antibacterial efficiency. Therefore acids like mandelic and lactic acids may have the capacity of killing bacteria sensitive to each or both bactericides after their release from the biofilm or after the weakening of the integrity or of the compacity of the biofilm. A compound like Betadine™ which has a low pH in solution (about 2) may also have such a role (see the Tween 20™/Betadine™ composition in Table 1). By itself, the combination Tween 20™/Betadine™ is not sufficiently effective. It is however believed that this combination would be efficient if supplemented with a denaturing agent and with other bactericides conferring to the combination a more aggressive dislodging power and a larger bactericidal spectrum. When the SDS detergent is used in combination with a potent oxidant like peracetic acid and/or hydrogen peroxide, these particular combinations need to be complemented by a chelating agent for maximizing the disintegration of the extracellular matrix. This suggests that the denaturing action of SDS is not sufficient by itself to make the biofilm in a state of sufficient vulnerability for the action of this particular type of bactericides; the chelating agent is necessary in this case. This contrasts with the action of mandelic and lactic acids which do not need the complementation by a chelating agent to be effective in combination with SDS. The mechanism of action of these acids on the biofilm is not elucidated. Their efficient action when combined with SDS may suggest that they more accurately affect the integrity of the extracellular matrix and/or that they affect the integrity of the bacteria, in such a way that they facilitate the action of SDS.
In all cases, the synergistic effect of the effective compositions of the present invention can perhaps be explained as follows. It is known that microorganisms present in a biofilm are generally much more resistant to bactericides than microorganisms present in a aqueous medium. The biofilm is thought to act as a physical barrier through which disinfectant agents fail to penetrate and kill the microorganisms present therein. Consequently, in order to eradicate a maximal number of the microorganisms present in small diameter water lines and particularly in the biofilm coating the inner wall of the small diameter water lines, it is important to simultaneously dislodge the biofilm from the inner walls of the lines so that the bactericide can efficiently attack as many microorganisms as possible. In sequence, the denaturing detergent is thought to help the penetration of the bactericide (and the chelating agent when present), dislodge a layer of biofilm which becomes suspended in the small diameter water lines where the bactericide can attack the microorganisms present. This process will expose a lower layer of the biofilm and of living microorganisms which will again be dislodged and killed. The dislodging action of the detergent and of the denaturing agent and the antibacterial action of the bactericide are thus improved.
Combinations containing EDTA may precipitate in the presence of acids. Fortunately, compositions containing SDS and mandelic and lactic acids do not need to be supplemented with EDTA. On the other hand, whenever necessary, it might be possible to choose a salt of a chelator which stays in solution at the desired pH. Also, compositions containing anionic detergents like SDS and a quaternary ammonium precipitate, as this is the case for the combination SDS/cetylpyridinium chloride (CPC). A composition containing a nonionic or a cationic detergent and cetylpyridinium chloride (CPC) has not been tried but it is believed that such a composition may be more suitable than the composition SDS/CPC. Of course, the same principles of efficiency of decontamination apply; such a combination may need to be supplemented with a denaturing agent and/or any ingredient affecting the integrity of the extracellular matrix for maximal efficiency. Also, this combination may be complemented with other bactericides to enlarge its host spectrum.
The formulation of five ingredients stays in solution even if it contains EDTA. It also stays in solution if CPC and PAA are added. When CPC is present, the presence of a weak acid like peracetic acid appears to help in stabilizing this composition. These two compounds have been found unnecessary in the present composition.
When the detergent used in the composition produces foam, it might be desirable to add an anti-foamer. Also, a colorant might be added to the compositions of this invention for easy monitoring of the extent of rinsing.
Fresh water lines supplying dental instruments are of a very small diameter, which excludes the possibility of scrubbing. The compositions of the present invention have the advantage of showing efficient decontamination in the complete absence of scrubbing in a convenient time of decontamination. The present invention is not only useful for dental instruments. It will become obvious that it is intended for other applications, e.g. decontaminating any types of tubing or containers on the surface of which microorganisms are adsorbed and form a biofilm. In such other applications, scrubbing or any other mechanical aid is not at all excluded. Should these compositions be used in pipes of a larger diameter and length, for example, wherein a non-cost effective large volume of decontaminating solution would be needed to fill completely these pipes, it is possible that a mechanical action would help in the distribution of the solution. A mechanical aid, when envisaged, can also help in reducing the duration of decontamination. It is further not excluded to add a vehicle allowing the disinfecting solution to stay in contact with the surface to be decontaminated.
It should also be appreciated that more concentrated solutions could be made inasmuch as the components thereof stay in a solubilized state, otherwise some or all of these components might be delivered in separate vials to be admixed in the final reconstituted volume and proportions of the above effective decontaminating solutions. This could reduce the manutention and storage of large volumes of decontaminating solutions when they are used for disinfecting large surfaces.
EXPERIMENTAL
The synergistic effect of the compositions of the present invention was demonstrated by the following experiment. Four sections of a small diameter (5 mm) water line, contaminated with a relatively thick biofilm on their inner walls were cut and placed in 5 mL test tubes in different decontaminating solutions.
The test tubes were then left for 18-24 hours at 21° C. Each section was then washed with distilled water and slit longitudinally to expose the biofilm on their inner walls and observed with a binocular microscope or by scanning electromicroscopy. Alternatively, the same procedure was followed on plastic plates coated with bacteria. The solutions that showed a significant eradication of the biofilm are listed in Table 1.
TABLE 1______________________________________ BiofilmSubstance* presence** Remarks***______________________________________Control + + + +H.sub.2 O.sub.2 + +PAA + +SDS + + +EDTA + + +MA +LA +CPC + +GLU +Solution.sup.a 0Solution without PAA 0 PPTTween 20 ™ + Betadine + +H.sub.2 O.sub.2 + PAA + + +H.sub.2 O.sub.2 + SDS +H.sub.2 O.sub.2 + EDTA + +H.sub.2 O.sub.2 + MA + -H.sub.2 O.sub.2 + LA +H.sub.2 O.sub.2 + CPC + +H.sub.2 O.sub.2 + PAA + LA + +H.sub.2 O.sub.2 + PAA + SDS + -H.sub.2 O.sub.2 + MA + LA + -H.sub.2 O.sub.2 + MA + LA + SDS 0H.sub.2 O.sub.2 + SDS + EDTA 0H.sub.2 O.sub.2 + PAA + MA +SDS + EDTA + -SDS + EDTA + MA 0 PPTSDS + EDTA + CPC 0 PPTSDS + EDTA + PAA + -MA + LA + -MA + LA + SDS 0MA + LA + EDTA + - PPTMA + LA + SDS + EDTA 0 PPT______________________________________ *MA = Mandelic acid, LA = Lactic acid, GLU = Glutaraldehyde, Peracetic acid = PAA, Solution = containing all elements listed supra, Control = Tube without treatment, SDS = Sodium dodecyl sulfate, CPC = Cetylpyridinium chloride. **Solutions were tested directly on contaminated tubes. Results are expressed on a scale representing presence of a biofilm; 0 = no biofilm, + + + = intact biofilm. ***The solution precipitates. .sup.a The solution contains the seven ingredients defined as one of the most advantageous mixtures. It may also contain five of the seven ingredients e.g. from which CPC and PAA are absent and SDS concentration is reduced from 2% to 1%.
A field test was conducted over a period of two weeks to four months to determine the cleaning and disinfecting efficacy of the compositions of the present invention. The composition was fed to the network of small diameter fresh water lines of a dentist's installation.
For comparative purposes, at the end of each work day, all the small diameter water pipes of the dentist's installation were filled with the diverse detergent-disinfectant combinations of the present invention, left overnight and the next morning thoroughly rinsed with water.
For each test, during the same work day, three water samples were drawn from various dental instruments, namely, an air/water gun, a high speed water turbine, and an ultrasonic tartar remover. These samples were placed under favorable conditions for microorganism growth. After five to seven days, the microorganism colonies were counted. The results were surprisingly encouraging; after numerous tests on the various instruments, an almost complete abolition of the microbian counts was obtained for the effective combinations of Table 1, e.g. where the presence of biofilm is registered=0.
The following antiseptics commercially available have been experimented and none of them have shown any efficient decontaminating activity against a biofilm:
BIOVAC™ (0.8%) Chlorohexidine, 3.20% EDTA, proteolytic enzymes, a dispersing agent).
EFFERDENT™ (Potassium monopersulfate, Sodium borate, Sodium lauryl persulfate, Sodium bicarbonate, Magnesium stearate, Simethicone).
POLYDENT™ (Potassium monopersulfate, Tetrasodium pyrophosphate, Sodium bicarbonate, Sodium borate).
STERISOL™ (Chlorohexidine, Glycerol, 38-F, Alcohol).
THERASOL™ (C-31G, NaF, Glycerine, Alcohol).
GLUTARALDEHYDE
ALCOHOL 70%
PATHEX™ (Phenolic)
SODIUM HYPOCHLORITE 2%.
Apparently, none of these preparations fulfill essential criteria for decontaminating surfaces coated with a biofilm, e.g. a detergent component, a denaturing and matrix-disintegrating component and a bactericide.
Although the present invention has been described hereinabove by way of preferred embodiments thereof, these embodiments can be modified at will, within the scope of the appended claims, without departing from the spirit and nature of the subject invention. | Disclosed herein is a synergistic cleaning and disinfecting composition for use in decontaminating biofilm-coated surfaces like fresh water lines providing water supply to dental instruments, these lines being susceptible to contamination by microorganisms and being susceptible to the formation of biofilm coatings on their inner walls, the composition comprising an effective amount of a detergent, an effective amount of a denaturing agent attacking the extracellular matrix formed between microorganisms and between microorganisms and the inner walls of these water lines and an effective amount of a bactericide for destroying the microorganisms. | 2 |
BACKGROUND AND SUMMARY OF THE INVENTION
This invention relates to a new and useful sawdust removal device for attachment to the exterior housing of a saber saw, i.e. a portable hand-held saw having a reciprocating blade and powered by an electric motor. With appropriate modifications, the device can be used with other electric-powered saws and electric-powered drills.
Saber saws are widely used by cabinet makers, carpenters and other persons engaged in the woodworking trades or metalworking trades, or both. In addition, saber saws are very popular with persons engaged in woodworking activities as a hobby. Most of these persons use a saber saw for similar purposes. Normally, a saber saw is used for precision cutting along a line drawn or scribed on the surface of the wood or other material being cut. Since a saber saw is hand held and guided, it is important for the person using the saw to have a clear and unobstructed view of the line which he or she is following during the cutting operation.
It is well known by both professional and amateur users of saber saws that sawdust, chips and other debris accumulate on the surface of the wood or other material being cut during normal operation of a saber saw. In general, such accumulations take place immediately in front of the saw blade. If such accumulations are not removed, the user of the saw will not be capable of seeing the line which he or she is attempting to follow. Under such circumstances, it is very probable that the user of the saw will make one or more cutting errors. Such errors are often very costly in terms of both lost time and materials.
Various means for removing sawdust, chips and other debris which accumulates on the surface of the wood or other material being cut are known in the art. For example the user of a saber saw can stop operation of the saw and tilt the wood or other material being cut to cause the sawdust, chips and other debris to fall from the surface of the wood or other material. Also, the user of a saber saw can brush the sawdust, chips and other debris from the surface of the wood or other material being cut with a cloth or a small brush. For safety reasons, it is preferable to stop operation of the saw when removing the sawdust, chips and other debris from the surface of the wood or other material being cut. And, of course, the user of a saber saw can either blow the sawdust, chips and other debris from the surface of the wood or other material being cut with compressed air or remove such accumulations with a shop vacuum cleaner. Unfortunately, many users of a saber saw do not have access to either a source of compressed air or a shop vacuum cleaner.
All of the above-described means for removing sawdust, chips and other debris from the surface of the wood or other material being cut with a saber saw have the disadvantage of requiring the user of the saw to interrupt his cutting operation to remove such accumulations. It is desirable to have a means for continuously removing such accumulations during operation of a saber saw. Continuous means for removing sawdust, chips and other debris from the surface of the wood or other material being cut during operation of a saber saw are described in U.S. Pat. Nos. 2,668,567, U.S. Pat. No. 2,902,067, and U.S. Pat. No. 3,033,252. Each of these patents discloses a means for diverting a portion of the discharged cooling air of the electric motor powering a saber saw through interior passageways in the saw housing to the immediate area of the reciprocating blade to blow away sawdust, chips and other debris. At times, a mild suction action occurs at the diverted air discharge opening of some known saber saws having such interior passageways causing the sawdust to be pulled into the face and eyes of the saw user. Even if this undesirable operating characteristic is not present with known means for continuously removing sawdust, chips and other debris, known means require substantial structural modifications to the design of conventional saber saws. It is desirable to have a device which can be attached to the exterior of the housing of a conventional saber saw. Ideally, no structural modifications to the design of the saw should be required for use of such a device.
The sawdust removal device of the present invention can be attached to the exterior of the housing of a conventional saber saw by traditional fastening means. No structural modifications to the design of the saw are required for use of this device. The sawdust removal device of the present invention traps air which is discharged from one of the two exhaust openings in the housing of a conventional saber saw and diverts the trapped air through an air delivery tube to a nozzle and diffuser located behind the reciprocating saw blade. This trapped and diverted air is discharged through the nozzle and diffuser and continuously blows sawdust, chips and other debris from the surface of the wood or other material being cut during use of the saber saw. The device can be attached to new saber saws during assembly operations at the manufacturing facility or attached to older saber saws by saw owners.
These and many other advantages and features of the present invention will be apparent from the following description of drawings, description of the preferred embodiment and the appended claims.
DESCRIPTION OF DRAWINGS
FIG. 1 is a perspective view of a saber saw having the sawdust removal device of the present invention attached to the exterior of the saw housing.
FIG. 2 is a side view of the sawdust removal device of the present invention.
FIG. 3 is a sectional view through lines 3--3 in FIG. 2.
FIG. 4 is a sectional view through lines 4--4 in FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred embodiment of the sawdust removal device of the present invention is illustrated in FIGS. 1-4. The sawdust removal device is comprised of two major components, namely, exhaust port cover 10 and air delivery tube 12.
In the preferred embodiment, exhaust port cover 10 is a solid body having an air trapping depression 14 which cooperates with an interior air passageway 16 to trap exhaust air discharged from one of the exhaust ports of a conventional saber saw and divert said air to air delivery tube 12. Air trapping depression 14 has an appropriate geometrical configuration for cooperation with the exhaust port to be covered. In FIGS. 2 and 4, air trapping depression 14 is shown as an elongated rectangular depression which gradually increases in depth from the upper end of the depression to the lower end of the depression. This particular geometrical configuration for air trapping depression 14 is suitable for exhaust port cover 10 when the sawdust removal device of the present invention is attached to the exterior of the housing of a saber saw having an elongated rectangular exhaust port. In FIGS. 2 and 4, interior air passageway 16 is shown as a cylindrical hole interconnecting air trapping depression 14 and air delivery tube 12.
In the preferred embodiment, air delivery tube 12 is a hollow tube having one end interconnected with the exit opening of interior air passageway 16. In FIGS. 1-4, this interconnection is shown as a force fit between one end of air delivery tube 12 and the exit opening of interior air passageway 16. Air nozzle 18 and air diffuser 20 are provided at the lower end of air delivery tube 12 to discharge and direct trapped and diverted exhaust air to continuously blow sawdust, chips and other debris from the surface of the wood or other material being cut by the saber saw.
Exhaust port cover 10 has been fabricated by machining the desired geometrical configuration from a solid block of plastic material. But, exhaust port cover 10 could be either machined or cast from an aluminum alloy or other suitable metal alloy. Also, it is possible to fabricate exhaust port 10 from a suitable plastic material by an injection molding process.
Air delivery tube 12 has been fabricated by cutting and bending copper tubing of the desired internal diameter to obtain the desired geometrical configuration. But, other types of tubing could be cut and bent to obtain the desired geometrical configuration for air delivery tube 12. Also, it is possible to fabricate air delivery tube 12 from a suitable plastic material by an injection molding process.
While inexpensive, lightweight structural materials are desirable for fabrication of the components of the sawdust removal device of the present invention, it is not intended that the present invention be limited in scope by the materials selected to fabricate the sawdust removal device. Furthermore, it is not intended that the present invention be limited in scope by the methods used to fabricate the sawdust removal device. In fact, it will be readily seen by those skilled in the manufacturing arts related to the fabrication of the sawdust removal device that the device could be fabricated as a single component rather than as two components in the manner described herein.
Traditional fastening means can be used to attach the sawdust removal device of the present invention to the exterior of the housing of a conventional saber saw. FIG. 1 illustrates the use of screw means 22 and 24 to attach the sawdust removal device to existing screw holes in the housing of a conventional saber saw. FIGS. 2, 3 and 4 illustrate the use of adhesive means 26 to attach the sawdust removal device to the housing of a conventional saber saw. Rivet means may be desirable if the sawdust removal device is attached during assembly of a new saber saw at the manufacturing facility.
The operation of the sawdust removal device of the present invention can best be understood by referring to FIG. 1 which shows the device attached to the exterior of the housing of saber saw 30. Saber saw 30 is equipped with a reciprocating saw blade 32. During operation of the saber saw, sawdust, chips and other debris are deposited on the upper surface of wooden board 34 after each upward stroke of reciprocating saw blade 32. But, the air which is continuously discharged from air nozzle 18 and distributed by diffuser 20 flows from its discharge point immediately behind reciprocating saw blade 32 and blows the sawdust, chips and other debris from that portion of the surface of wooden board 34 which is in the immediate vicinity of reciprocating saw blade 32. Accordingly, the user of saber saw 30 has a clear and unobstructed view of line 36 at all times during operation of saber saw 30.
While the present invention has been disclosed in connection with the preferred embodiment thereof, it should be understood that there may be other embodiments which fall within the spirit and scope of the invention as defined by the following claims: | A sawdust removal device for attachment to the exterior housing of a saber saw or other electric-powered saw or drill. The device traps air discharged from an exhaust port in the saw or drill housing and diverts that air to continuously blow away sawdust, chips and other debris which accumulates on the surface of the material being cut or drilled during operation of the saw or drill. | 1 |
CROSS-REFERENCES TO RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 10/440,560, filed May 16, 2003, which is a continuation application of U.S. patent application Ser. No. 09/943,805, filed Aug. 30, 2001, now U.S. Pat. No. 6,591,123, which claims the benefit of U.S. Provisional Application Ser. No. 60/299,616, filed Aug. 31, 2000, all of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
The present invention relates to oximetry sensors and, in particular, pulse oximetry sensors which include coded information relating to characteristics of the sensor.
Pulse oximetry is typically used to measure various blood flow characteristics including, but not limited to, the blood-oxygen saturation of hemoglobin in arterial blood, the volume of individual blood pulsations supplying the tissue, and the rate of blood pulsations corresponding to each heartbeat of a patient. Measurement of these characteristics has been accomplished by use of a non-invasive sensor which passes light through a portion of the patient's tissue where blood perfuses the tissue, and photoelectrically senses the absorption of light in such tissue. The amount of light absorbed is then used to calculate the amount of blood constituent being measured.
The light passed through the tissue is selected to be of one or more wavelengths that are absorbed by the blood in an amount representative of the amount of the blood constituent present in the blood. The amount of transmitted light passed through the tissue will vary in accordance with the changing amount of blood constituent in the tissue and the related light absorption. For measuring blood oxygen level, such sensors have been provided with light sources and photodetectors that are adapted to operate at two different wavelengths, in accordance with known techniques for measuring blood oxygen saturation.
Nellcor U.S. Pat. No. 5,645,059, the disclosure of which is hereby incorporated herein by reference, teaches coding information in sensor memory used to provide pulse modulated signal, to indicate the type of sensor (finger, nose), the wavelength of a second LED, the number of LEDs, the numerical correction terms to the standard curves, and an identifier of the manufacturer.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a pulse oximeter system in accordance with an exemplary embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The present techniques provide a memory chip for use in an oximeter sensor, or an associated adapter or connector circuit. The memory chip allows the storing of different data to provide enhanced capabilities for the oximeter sensor. In addition to providing unique data to store in such a memory, the techniques include unique uses of data stored in such a memory. The data stored in the memory chip includes information relating to use of the oximeter sensor. For example, the memory chip may encode a sensor model identification that can be displayed on a display screen when the sensor is connected to an oximeter monitor. The memory may also encode a range of operating parameters such as light levels over which the sensor can function or a maximum drive current. The operating parameters are read by a controller circuit which uses the data read from the memory chip to control the functioning of the pulse oximetry system.
Part I
FIG. 1 is a block diagram of a pulse oximeter system incorporating a calibration memory element 56 according to the invention. In one embodiment, memory element 56 is a two-lead semiconductor digital memory chip. The calibration element is part of the sensor 50 which also includes red and infrared LEDs 52 as in the prior art, along with a detector 54 . If desired, LEDs 52 may be replaced with other light emitting elements such as lasers.
The oximeter includes read circuit 60 , drive circuit 66 , look-up tables 62 and 63 , controller 64 , amplifier 72 , filter 74 , and analog-to-digital converter 76 . Read circuit 60 is provided for reading multiple coded values across the two leads 51 , 53 connected to calibration element 56 . One value is provided to a look-up table 62 to determine appropriate wavelength dependent coefficients for the oxygen saturation calculation, as in the prior art. The other value(s) are then provided to another look up table(s) 63 which provides input (e.g., coefficients) to other calculations performed by controller 64 . These additional calculations may enhance the performance and/or safety of the system. Controller 64 provides signals to a drive circuit 66 , to control the amount of drive current provided to LEDs 52 .
As in the prior art, detector 54 is connected through an amplifier 72 and a filter 74 to an A/D converter 76 . This forms a feedback path used by controller 64 to adjust the drive current to optimize the intensity range of the signal received. For proper operation the signal must be within the analog range of the circuits employed. The signal should also be well within the range of A/D converter 76 (e.g., one rule that may be applied is to adjust LED drives and amplifier gains so that both red and IR signals fall between 40% and 80% of full scale reading of converter 76 ). This utilizes correct and independent settings for both the red and infrared LEDs. The current techniques allow for another feedback path which may alter the LED settings based on other sensor characteristics contained in the coding of the calibration element 56 , which is discussed in further detail below.
Memory 56 may, for example, be implemented as a random access memory (RAM), a FLASH memory, a programmable read only memory (PROM), an electrically erasable PROM, a similar programmable and/or erasable memory, any kind of erasable memory, a write once memory, or other memory technologies capable of write operations. Various types of data useful to a pulse oximetry system can be stored in memory 56 . For example, data indicating a sensor model identification code corresponding to a particular sensor model can be encoded in memory 56 . Also, an action can be encoded into memory element 56 indicating an action to be performing by the oximeter monitor in response to reading the sensor model identification code.
For example, an identification code in the form of text indicating the specific model of sensor can be digitally encoded into memory 56 and read by the oximeter monitor when the sensor is connected to the oximeter. An action indicating that the sensor model text is to be displayed by the oximeter monitor on a display screen can also be encoded in memory 56 . The identification code can be displayed in human readable form on a display screen connected to the pulse oximeter monitor. The identification code allows the oximeter instrument to display a text string indicating what sensor model is being used, e.g. “Nellcor OXISENSOR I1 D-25,” “Adult Digit Sensor,” or “Agilent N-25.”
Alternately, display text for a plurality of specific models of pulse oximeter sensors can be stored in a lookup table coupled in parallel with lookup tables 62 and 63 in the pulse oximeter monitor. The pulse oximeter monitor reads a sensor code from memory 56 when the sensor 50 is connected to the oximeter. The sensor identification code stored in memory 56 is used to locate display text stored in a lookup table that corresponds to a specific sensor model. The oximeter can display the display text for the specific sensor model on a display screen for viewing.
The present techniques may eliminate the printing of a model name and number on the sensor itself. Even when model names and numbers are printed on a sensor, the text may become illegible after several uses. Displaying text that corresponds to a specific sensor model can be highly useful for users of pulse oximetry sensors. For example, it may be important to identify a sensor model so that instructions relating to a particular sensor model in the manufacturer's handbook can be identified. In addition, it may be desirable to identify a sensor model name or identification number when corresponding with the manufacturer.
Digitally encoded data indicating a sensor model type in memory 56 or in a lookup table may be used to determine whether a sensor model is compatible with a particular pulse oximeter monitor. For example, memory 56 may contain a code indicating a sensor model type that is read by controller 64 . Memory 56 can also encode an action indicating that controller 64 is to compare the code from memory 56 with a list of codes in a lookup table (or other oximeter monitor memory device) to determine if the sensor is compatible. If controller 64 successfully matches the code read from the sensor, the display text indicating the sensor model type is displayed on the display screen. If controller 64 does not recognize the code, an error message may be displayed on the display screen indicating that the oximeter monitor does not recognize the sensor, and the oximeter may refuse to operate until the sensor is replaced.
A code can be stored in the sensor memory 56 identifying the sensor manufacturer. An action indicating a use for the code by the oximeter can also be stored in memory 56 . The code is read by controller 64 and is used for the purpose indicated by the action. The action may, for example, indicate that the code in memory 56 is to be used to indicate operability with oximeter monitors of other manufacturers. Controller 64 can recognize certain codes as indicating compatible oximeter sensors. If the oximeter monitor does not recognize the code, then controller 64 can display an error message on a display screen indicating that the sensor is not compatible, and/or controller 64 can shut down circuitry in the oximeter monitor that senses signals from the sensor until the sensor is replaced with a compatible sensor.
Other information may also be encoded into memory 56 , read by the 17 monitor, and displayed for user reference. For example, language codes or country codes can be stored in memory 56 , read, and displayed to the user. The user can select a language or country code so that messages are displayed, such as error messages, in the selected language or a language corresponding to the selected country. Messages may also be encoded into memory 56 . For example, safety messages relating to the proper use of the sensor can be encoded in memory 56 and displayed on a display screen in human readable form.
It is often desirable to upgrade the algorithms that are used by the oximeter to determine blood oxygen saturation levels, pulse rates, pulse amplitude, blood pressure, and other patient data as technology progresses and the operating parameters (such as filter coefficients) are refined. Because oximeter sensors are typically much less expensive to replace than oximeter monitor instruments, it is desirable to encode data corresponding to the updated algorithms in the sensors rather than in the oximeter monitors.
One method for performing these updates is by encoding revisions to the algorithms used for calculating the patient parameters in memory within the oximeter monitor, while encoding updated software code or tuning coefficients in sensor memory 56 . The updated code or coefficients correspond to updated algorithms that are read by the oximeter monitor so that the updated algorithms can be applied to the standard algorithms preprogrammed into the oximeter. For example, a line of software code in an algorithm used by the oximeter monitor can be replaced by a updated line of code stored in memory 56 .
Controller 64 can read the updated code or coefficients from memory 56 and apply the updated algorithms to signals received from detector 54 to determine accurate blood oxygen saturation levels, pulse rates, pulse amplitudes, perfusion data, blood pressure, and other patient data. The updated algorithms can also be used to allow only supported features to be used. In one embodiment, once updated, the new code or coefficients become permanently stored in the oximeter monitor, along with a new algorithm revision number, and are utilized for all future sensor use until later updated.
Encoding a sensor model identification code could also be used to accommodate sensor-specific operating parameters such as LED drive currents or “sensor off” characteristics (as an alternative to programming the value of drive current or “off” characteristics themselves). Under normal operating conditions, photosignals coming from the sensor LEDs generally fall within a certain range. When a sensor is removed from a patient, or falls off on it's own, the photosignal usually changes. This is particularly true for the reusable clip-style sensor, because in their normal disconnected state, the LEDs shine directly onto the photodetector unimpeded by, for example, tissue. By programming a “threshold photocurrent” into memory chip 56 , reliable detection of a “sensor is off the patient” condition can be accomplished. In this example, exceeding a certain detected threshold light level is an indication that the sensor is not on a finger or other site.
For certain other sensors, a low light level may be indicative of the sensor being off. An adhesive sensor, for example, lays flat when in it's natural state—little LED light may reach the detector. Encoding an expected range of light levels for the specific model of sensor being used into memory 56 allows enhanced detection of when the sensor is improperly placed or has been removed. When controller 64 senses that the light level output detected by photodetector 54 has fallen below or exceeded the expected range of light levels encoded into memory 56 , the oximeter monitor can display an “sensor off” message on a display screen indicating to the medical personnel that the sensor is not in an operable position and that valid data cannot be detected (i.e., a sensor off condition). The oximeter monitor can also emit an alarm signal until the light level detected by photodetector 54 reaches the expected range.
If desired, expected ranges of light levels (or other parameters such as pulse size) that are specific to a particular patient may be encoded and saved into memory 56 by the clinical through the oximeter. The oximeter compares the expected range for the parameters encoded into memory 56 with data received from the photodetector to determine a sensor off condition each time the sensor is used until the range data is overwritten with new data. This is advantageous because light levels, pulse sizes, and other parameters detected by the photodetector can vary significantly from patient to patient.
Existing pulse oximeter sensors determine whether a sensor is off the patient, or not in good contact by using a number of metrics. Those metrics include pulse size, pulse variability, IR/Red correlation, light level variability, pulse shape, and pulse regularity. Not only the light level, but any of these other values could vary depending on the type of sensor, the characteristics of an individual patient, and the location on the body where the sensor is to be applied. Thus, sensor memory 56 could encode information about the expected variation in any of these metrics for the particular sensor type or model or a particular patient, and these metrics may be used in determining if a sensor is off from any combination of these or other metrics as an indication that the sensor is off the patient.
For example, pulses could be typically weaker on the forehead compared to the finger. Memory device 56 of an oximeter sensor designed for use on the forehead of a patient can be encoded with a range of pulse sizes as well as a range of light levels that are expected from that particular oximeter sensor model. If desired, memory 56 can encode a range of numbers based upon light level and pulse size (and other parameters). For example, memory 56 can encode a range of numbers representing the expected range of pulse size times light level received from detector 54 for a specific sensor model.
Controller 64 reads and decodes the pulse size, light level range, and other data encoded in memory 56 . Controller 64 then compares the expected pulse size and light level range data with the information received from detector 54 . When the pulse size and/or light level data received from detector 54 exceeds or falls below the expected range data encoded in memory 56 , the oximeter monitor displays an output message, e.g., a warning of a poor signal, on the display screen indicating that the sensor is not operable or emits an alarm signal. Further details of a Method and Circuit for Indicating Quality and Accuracy of Physiological Measurements are discussed in U.S. patent application Ser. No. 09/545,170, filed Apr. 6, 2000 to Porges, et al., which is incorporated by reference herein in its entirety.
Running LEDs 52 at a high drive current results in more light output from the LEDs, thus improving the signal-to-noise ratio of the blood oxygen saturation signal from detector 54 , but comes at a cost of causing additional heat dissipation (i.e., the LEDs run “hotter”). As current flows through the sensor LEDs, the LED emits heat (i.e., the LED power=LED drive current times the voltage drop across the LED). The majority of the energy output by the LEDs is dissipated as heat, and the smaller portion of the energy output by the LEDs is emitted as light. This heat typically causes the temperature of the skin under the sensor to rise by an amount that that depends on the heat dissipation properties of the sensor. Current safety regulations and guidelines limit the temperature of the skin contacting portions of the sensor to remain at or below 41° C. Sensors that do a poor job of directing the heat away from the skin contacting surface, should use a lower LED drive current. Sensors with good thermal management can utilize higher drive currents without risk to the patient.
Accordingly, by encoding the maximum safe LED drive current into the sensor itself, the oximeter instrument can utilize the highest safe drive current for the sensor being used to attain the greatest amount of LED light without risk of injury. The maximum safe drive current allowed to achieve a skin temperature at or below a maximum level can be determined in advance through testing for a given oximeter sensor model. That maximum drive current can be encoded into memory 56 and read by controller 64 when the sensor is connected to the oximeter monitor. Controller 64 then communicates with drive circuit 66 to drive LEDs 52 at or near the maximum drive current value read from memory 56 , but to prevent circuit 66 from driving LEDs 52 with a current that exceeds the maximum drive current.
Part II
Embodiments of the present technique include the following:
Sensor Model ID
Encoded text of the specific model of sensor would allow the instrument to display a text string indicating what sensor is being used, e.g. “Nellcor OXISENSOR II D-25” or “Adult Digit Sensor” or “Agilent N-25”. Alternately, a sensor code could be stored that points to a lookup table of display text. Encoding sensor model ID could also be used to accommodate sensor-specific operating parameters such as LED drive currents or “sensor off” characteristics (as an alternative to programming the value of drive current or “off” characteristics themselves).
Sensor Model—Specific Information
Coefficients for Taylor's Series Calibration Curves
The sensor may store a general polynomial curve. Other families of polynomials, such as Tchebyschev polynomials, could be used as well. This may also pertain to other calibration information, such as temperature calibration and force transducer calibration. This allows new sensor types (such as a sensor with an offset emitter and detector).
Sensor Adjustment/Re-Application Light Levels
Sensor Off Light Levels
Under normal operating conditions, photosignals coming from the sensor LEDs generally fall within a certain range. When a sensor is removed from a patient, or falls off on its own, the photosignal usually changes. This is particularly true for the reusable clip-style sensor, since in their normal disconnected state, the LEDs shine directly onto the photodetector unimpeded by, for example, tissue. By programming a “threshold photocurrent” into the memory chip, reliable detection of a “sensor is off the patient” condition can be accomplished (in this example, exceeding a certain detected light level is a sure sign the sensor is not on a finger or other opposed site). For certain other sensors, a low light level may be indicative of the sensor being off (an adhesive sensor, for example, lays flat when in its natural state, so little LED light may reach the detector). Encoding an expected range of light levels for the specific model of sensor being used allows enhanced detection of when the sensor is improperly placed or has been removed.
Temperature at which to Switch to STORM Algorithm
The STORM algorithm here refers to the sensors designed to be used where “motion provides the signal”, i.e., the cardiac pulse need not be present or discernible in order for the oximeter to provide SpO 2 values. Instead, the red and IR waveforms resulting from the motion itself are used for determining the arterial saturation. This feature is possible for tissue beds that are well “arterialized” (a large supply of arterial blood relative to the metabolic needs of the tissue) resulting in a small aterio-venous saturation difference, as well as other signal characteristics that are not germane to this discussion. It has been observed that the necessary degree of arterialization correlates well to being “well perfused” at the tissue site, which itself correlates well to the tissue bed being warm. Thus by monitoring the temperature of the skin at the sensor site, and by knowing a value of temperature (programmed into the memory chip) at which the “motion-is-signal” algorithm can be utilized for the specific sensor design being used, improved reading accuracy through motion can be better accomplished.
Additional Information on Use of Pins
Contact Switch—Sensor Off
Similar to the contact electrodes of the Nellcor FS-14 fetal sensor, an extrinsic probe of skin contact can be used to indicate whether the sensor is in adequate contact to the patient. This extrinsic probe could be accomplished, for example, through an impedance measurement across two electrodes, a force or pressure switch that is sensitive to whether adequate force or pressure is present in the sensor placement, or through other means. Dedicated sensor connector pins, or pin-sharing, could be used to accomplish this additional measure of sensor-patient contact.
Chemical Sensor for EtO Cycles
An electro-chemical or thermal device that senses and stores to memory the number of exposures (zero, once, or potentially more than once or the actual number) to sterilization cycles could be used to capture the history of the sensor. Excessive exposure to sterilization cycles degrades a number of components in the sensor, and can affect its performance. A sensor exceeding a certain number of exposures could cause a display to indicate the sensor needs to be replaced.
Sensor Expiration
This need not be a separate device, but the memory could contain a date after which time the sterilization can no longer be certified as being effective. Sterilization can be sensed and the date recorded automatically by the sensor itself.
Sensor Expiration Date/Sensor Parking: Meter
At the time of manufacture, the expiration date of the sensor may be written into the memory chip. The memory-enabled instrument would then do something with this knowledge (e.g., indicate “expired sensor”, or refuse to function if expired). Alternately, the elapsed time of sensor usage could be tracked in the memory chip (written to it by the instrument) and the sensor would “expire” after a memory programmed maximum (greater for reusable sensors than for single-use sensors).
Auto Shut-Off
After sensor expiration, the instrument may refuse to function with this sensor and would indicate that a fresh sensor is needed. Furthermore, the sensor could be disabled by running a high current through it, or by other means.
Warranty Date
Similar to the expiration date, the date of expiration of the sensor warranty could be written into the memory chip (e.g., 2, or 6, or 12, etc. months from the date of 10 manufacture or the date of first use). The instrument would give some indication of this as appropriate.
Patient Specific Information (Written to Sensor from Monitor)
Trending and/or data logging of patient monitoring parameters may be stored in the memory of the memory chip. As the patient and sensor travel from ward-to-ward of the hospital, and consequently plug into different oximeters, the patient-specific data could be displayed as it is contained in the patient's dedicated sensor. Examples of the type of data are given below:
Trending
Low High Sat
The lowest and/or highest SpO 2 value during the monitored time, or the lowest/highest values over the past specified monitoring time (e.g., 2 hours, 1 day, etc.)
Duration of Monitoring
How long has the patient been monitored by the pulse oximeter? (elapsed time counter).
Beginning and End of Monitoring
Clock time of when the monitor was turned on and off.
Pre-Set Alarm Limits
The alarm limits used with this patient become written to the memory chip by the instrument. This allows patient-specific alarm values to be set and memorized so that as the patient moves from monitor-to monitor (the sensor staying with the patient), the appropriate alarm limits need not be reset each time on the new monitor. Instead, this only needs to happen once, or whenever the clinician adjusts alarm limits.
Changeable Key
Data encryption utilizes private and/or public keys to scramble the data written to the memory chip and later decipher the data so that only authorized devices are supported. To further prevent the use with a monitor that is not certified to provide correct results, the sensor manufacturing system could periodically change the private and/or public keys. The change in the key could be communicated to the instrument via the memory chip in encrypted form. The purpose of this feature is to elevate the level of security in the memory system.
Monitor Code Upgrades from Modem or Sensor
Distributing code updates in memory. Whenever an oximeter notes that a code update field is present in the sensor, it would check whether the proposed update had previously been installed, and (if not) whether any indicated prerequisites were present (e.g. a code patch might not function properly in the absence of a previously-circulated patch). If appropriate conditions are met, the code upgrade would be installed. If prerequisites are missing, a message would be displayed to the user, telling him how to obtain the prerequisites (e.g. call Nellcor).
Black Box Encoder (Patient History, Serial Number of Box. Etc.)
Use the memory as a general-purpose carrier of patient data, covering not just oximetry but a lot of other information about the patient.
Optical Efficiency Correction
If it is desirable to know where a particular patient lies in COP space, it is useful to know the inherent brightness of LEDs, sensitivity of detector, and anything else about the particular sensor assembly (e.g. bandage color and alignment) that will affect the amount of light which the sensor receives. Given that information, a measure of the patient's optical transmissivity may be computed for each LED wavelength, which depends almost entirely on the properties of the patient. Signal to noise ratio of the oximeter is probably determined by the size of the detected signal, not by the transmissivity of the patient alone. This could take advantage of DC transmissivity of the tissue to improve the accuracy of pulse oximetry.
Another reason for recording LED and detector parameters in the sensor memory is to provide a basis for later research on the drift of these parameters due to various environmental conditions which the sensor experiences. Parameters of interest include not only LED power and detector sensitivity, but also LED wavelengths, FWHM, and secondary emission level.
Pigment Adjustment Feature
For some types of sensors, the accuracy of the sensor may be different for patients with different skin color. The sensitivity of accuracy to skin color may depend on sensor model. The sensor might contain a sensitivity index, indicating how large an adjustment in readings should be made as a function of skin color. Skin color might be obtained by user entry of the data (e.g. menu selection). Another option would be for the sensor to measure skin color. One way to achieve the latter option would be to provide transmission sensors with auxiliary detector for “reflected” light. In combination with the optical efficiency information noted above, the signal levels reported by the auxiliary detector would sense to what extent the patient's skin was affecting red and IR pathlengths differently, and hence to what extent readings needed to be corrected.
Accelerometer on Chip
This might be used in a scheme in which the memory chip was on the bandage, not in the connector. This combines a MEMS accelerometer with any of several different chips that might usefully be placed in the sensor head, local digitizing chip, preamp chip, memory chip.
Accelerometer data may be used to warn of the presence of motion (in which case special algorithms may be called into play or oximetry may be suspended), or actually to help correct for motion (to the extent to which we can produce algorithms which can predict physio-optic effects of known motion).
Optical Shunt
The amount of optical shunting could be measured for each sensor, or family of sensors. The value would be stored in the sensory memory for the monitor to read and use to adjust the processing coefficients.
Monitor Chip Temperature
The temperature of a red LED, in particular, affects its principal wavelength, which affects calibration. For one class of LEDs, the wavelength shifts by about 0.14 nm/C. The memory chip might contain circuitry capable of monitoring a thermistor or thermocouple, or the memory chip could be mounted in proximity to the LED (e.g. under it), so that it could sense directly the temperature of the LED, and provide a calibration correction accordingly.
Monitor Ambient Temperature
This might be used, e.g., in overseeing the operation of a warmed ear sensor. There is a thermal cutout in the control system of the WES, that causes operation to terminate if the sensor goes over a certain temperature. This is a component for protecting the patient against burns. If the reason for a high sensor temperature is that the environment is warm, it could be quite acceptable to continue oximetry, even though warmer operation would be shut down. In the absence of knowledge about environmental temperature, a high temperature reading might have to be assumed to mean that something was wrong with the sensor, in which case all operation might have to cease. An environmental temperature sensor in the plug could help to tell which rule to apply. Again, the memory chip could record the calibration of whatever device was used for thermometry.
A passive component on the memory chip could be the thermometric sensor, and a resistance or voltage measuring device in the instrument could read out that sensor. Thus, ambient temperature sensing might not require that large changes be made in the memory chip.
Temperature Amplifier/Detector
In illuminating the skin for the purpose of making oxygen saturation measurements, some heat is generated by the LED emitters. Tests have been done to establish the maximum safe current for the LED drive which will assure that the skin temperature stays within a safe value for the worst case sensor/patient conditions. This means that in all cases the sensor will be operated at cooler than the maximum temperature but in most cases well below the maximum temperature.
To establish the optimum signal for the measurement, it is desirable to drive the LEDs with higher current than is imposed by the above limitations. The temperature amplifier/detector would allow the LEDs to be driven to a level that still results in a safe temperature by monitoring the temperature, yet in many cases allow more drive current, and therefore higher signals, which could give better readings.
The inexpensive thermistor devices that could be used in this application are characterized to allow the measurement to be accurate. These characterization values could be stored in the sensor where the thermistor is located. While in operation, the oximeter would be able to read the characterization values from the sensor, measure the resistance of the thermistor, and calculate accurately the temperature of the skin surface where the thermistor is located. This would keep the patient safe from burns and still provide the best signal available.
RCAL Resistance Built into Chip
In legacy oximetry sensors there is a resistor which is selected and installed in the sensor connector, to correspond to the wavelength of the red LED. The wavelength difference from LED to LED has an impact on the calibration of the saturation measurement, if not compensated for. The oximeter will read the value of resistance and adjust its calculation accordingly.
When adding the memory chip, memory compatible oximeters will be able to obtain the necessary calibration coefficients from the memory chip but the legacy instruments will still need a calibration resistor value. If the resistance were built-in to the chip and trimmed or selected at manufacture then only one device would need to be installed in the sensor connector. That would reduce the overall cost, yet keep the sensor compatible with both the legacy instruments and the new memory compatible instruments.
Secondary Emission Measurement
The oximeter is measuring the relative transmission of the red and infrared light through the tissue. LEDs have a characteristic called secondary emission which is indicative of the amount of light, at wavelengths other than the primary wavelength, that is being emitted. This characteristic will change the calibration of the device if not compensated for. It is possible to make an oximeter that will function within calibration if the secondary emission is known and compensated for. If the LED were characterized during manufacture and then the secondary emission values entered into the memory chip, the oximeter would be able to read those values and compensate for them so that the sensor was used properly. This would increase the range of LEDs that could be used for oximetry, reduce cost and provide better calibration across a wider range of LED emitters.
Patient ID (Potentially as Tracking Device, Archiving Patient History, Etc.)
Currently sensors are placed on patients at one hospital site and stay with the patient from hospital site-to-site. It would be helpful to have the patient ID carried along in the sensor so that the record keeping, which occurs at each site, would be able to link the recorded information with the patient. Without patient ID, the tracking has to be done manually. With trend information being stored in the sensor it also would be desirable to have the patient ID included so that as the patient went from location to location, the new location's staff could verify old information and be assured that it correlated with the patient they were receiving.
Encode Contact Resistance (E.g. For Oxicliq)
When making measurements of the resistance that is placed in the sensor for calibration information purposes, one of the factors that can influence that measurement is the contact resistance of the connectors that are between the oximeter and the resistor itself. In order to compensate for connectors that are significant in their impact on the measure, one could encode the contact resistance of the connector and subtract that algorithmically from the measured resistance to get a more accurate measurement of the resistance of the calibration resistor. This would enhance the accuracy with which the resistance measurement is made and, therefore, make the instrument less prone to inaccuracies in saturation calculation and display.
Measure Capacitance to Balance Common Mode Rejection
One of the interfering noise sources that plagues oximetry is that of common mode noise. This can come from the surrounding electrical environment. Other instruments, lighters, drills etc. can produce electrical fields that can couple into the cable between the patient and the oximeter. Once coupled-in, they can make measurements more difficult, less accurate, or not possible, depending on the severity of the noise. To help reduce this common mode noise, differential amplifiers are used for amplifying the signal from the sensor. These amplifiers amplify only the difference between two signal wires. Thus, if the common mode signal is coupled exactly the same into both wires, the amplifier will not amplify it because the same signal is present on both wires.
If the two wires have different coupling to their electrical environment, then they will present different signals, and the difference will be amplified as if it were a signal. One component that influences this coupling is the capacitance of the lines to the outside world. This is affected by the manufacture of the cable, materials, twists in the wire, etc. If one measured the cables during manufacture and then stored that information in the memory chip, it could be read when the oximeter is operating. Once the capacitances for the two wires to the shield are known, the instrument could be provided with a tunable capacitance device that would then balance the two lines again and make the noise coupling to the lines better matched. This would reduce the amount of susceptibility to the external noise that got coupled into the patient cable. Reduced noise results in better measurements or the ability to make measurements at all on some patients.
Fiber-Optic Infrared Wavelength Shift
The relative wavelengths of the red and infrared light that is used to make the measurement in oximetry are important to know so that calibration can be maintained. In traditional LED oximetry, the LED sources are at the skin so that whatever wavelength is emitted is what is sensed by the photodiode that receives the light. The red LED is the only one that we need to characterize for accurate saturation measurements to be realized. The saturation is less sensitive to the IR wavelength as long as it stays fixed in the acceptable range that has been specified for the IR LEDs.
When using plastic fibers for transmission of the light, there is a wavelength dependent absorption caused by the fiber. This has the effect of altering the apparent center wavelength of the IR source, which can affect calibration of the unit. By characterizing the fiber for its shift, one could then provide the proper compensation in the algorithm that calculated the saturation. This would restore the accuracy that would otherwise be lost in fiber transmission of the light.
Inform Monitor of Extra LEDs
There are limitations on the number and type of blood constituents that can be sensed using the two conventional LED wavelengths of the oximeter. The accuracy of the oximetry measurement can also be improved by using different wavelengths at different saturation ranges. An analysis unit could be developed that would utilize either or both of these features. To do this, it would be able to drive additional LEDs. The additional LEDs could be driven along with the traditional ones or separately. The oximeter (or additional constituent measurement unit) would provide the capability to calculate values for these other wavelengths, and the sensor would provide the additional information to allow the oximeter to make that calculation. These could be stored in the memory.
Active Ambient Light Measurement
One of the problems with oximetry sensors is the interference caused by ambient light in the environment. This can be made worse when a sensor comes loose or when the ambient light is extremely high in value. By characterizing the sensor, one could know what level of ambient light could be expected or tolerated, and give a warning to the user when the level has been exceeded. This would give them the opportunity to adjust the sensor, the light, or both to affect an improvement in the performance of the oximeter.
Active Pressure Adjustment for Modulation Enhancement
The stronger the pulsatile signal, the better the chances are of measuring the saturation accurately. One way to enhance the modulation percentage is to apply pressure in the range of the median pulsatile pressure. If this were implemented, one could use relatively low cost transducers and supply calibration coefficients in the memory to allow accurate pressure readings to be made. The memory could also contain the pressure settings and/or expected modulation enhancement capability to determine effectiveness of the pressure enhancement.
Measure Perfusion
The amount of perfusion affects the amount of modulation, and thus the AC signal. This affects both the percentage of modulation vs. the DC amount, and the absolute size of the modulation. The measured modulation, or other measurement of perfusion, can be stored in memory for trending or setting limits on acceptable perfusion before movement or other adjustment of the sensor is required.
Keep Track of Last Time Sensor Moved or Disconnected
The time of movement or disconnecting of the sensor could be written into the memory. Disconnecting can be detected from the interruption of the signal to the monitor. Moving can be detected by a sensor off detection, and a subsequent sensor on detection. Alternately, aggressive movement could be detected and interpreted as moving of the sensor, or a combination with a sensor off detection could be used.
Identify Private Label Sensors
A code can be stored in the sensor memory identifying the sensor manufacturer. This code can be read and used to indicate operability with monitors of other manufacturers, or to indicate any conversion algorithm that may be needed for a signal from a sensor to be used by a monitor from a different manufacturer. The code can also be used to allow only supported features to be used.
Measure Sensor Wetness
A moisture sensor or impedance sensor can detect the amount of wetness of the sensor. This can be used for different purposes and can be stored in the sensor memory for trending or monitoring. To determine sensor malfunction, the sensor can be disabled if the wetness exceeds a threshold, which could be stored in the sensor memory. Some sensors may not provide for isolation of the patient from the electronics for excessive wetness. The maximum allowable wetness could be stored in the sensor memory.
Sensor Isolation Indicator
The sensor memory could identify that the sensor provides isolation, so wetness is not a concern. Alternately, it could indicate that isolation is not provided by the sensor, or a limited amount of isolation is provided.
Low Power Mode Identifier (Sensor Tells Oximeter to Sleep or Wake Up)
A portable battery-powered monitor can power down when the saturation is at a good level, and the patient is stable. Minimal circuitry in the sensor could be used to do sufficient processing to tell the monitor when to wake up.
Battery to Run Digital Chip
A battery can be included in the sensor for a wireless connection to a monitor. Alternately, a battery could be used to continue to send data when the monitor is powered down.
Motion Generator (“Thumper”)
The sensor can include a cuff (which inflates and deflates) or other mechanical mechanism for inducting motion to get a signal or for inducing pulsitile blood flow to improve the signal.
Sensor Force Indicator (E.g., Too Tight)
A transducer can measure the amount of force on the sensor. This can be compared to a maximum value stored in the sensor memory to determine if the sensor is on too tight. The tightness can also be recorded and monitored. For example, a patient could swell, and this could be determined from the trend information and provided as information to a clinician on a display.
Force Transducer Calibration to Get Pressure
A calibration value can be stored in the sensor memory for converting a force measurement into a pressure measurement. A force transducer can then be used to measure pressure.
Number of Wavelengths
The sensor memory can store an indication of the number of wavelengths used in the sensor, and could store the wavelengths themselves.
Drive Information
The sensor memory can store information about when to drive which LEDs. They could all be driven at once, or a subset could be driven, for example.
Display for Additional Wavelengths
The memory can store information about what parameters are to be analyzed and displayed when the extra wavelengths are used. Oxygen saturation may be displayed when 2 wavelengths are used, while additional information could be displayed when an extra wavelength or more are used (Hct, COHb, etc.).
Recycling Times
Each time a sensor is recycled (sterilized and reconstructed), a number in the sensor memory can be incremented. This can be used to prevent operation of the sensor if it has been recycled more than the allowed number of times (e.g., 3 times).
While the present invention has been described herein with reference to particular embodiments thereof, a latitude of modification, various changes and substitutions are intended in the foregoing disclosure, and it will be appreciated that in some instances some features of the invention will be employed without a corresponding use of other features without departing from the scope of the invention as set forth. Therefore, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope and spirit of the present invention. It is intended that the invention not be limited to the particular embodiments disclosed, but that the invention will include all embodiments and equivalents falling within the scope of the claims. | Embodiments of the present invention include systems and methods that relate to a sensor with memory. Specifically, one embodiment includes a method of sensor operation, comprising emitting light from a light emitting element of the sensor, detecting the light with a light detecting element of the sensor, storing sensor model identification data within a memory of the sensor, and providing access to the memory to facilitate reading the sensor model identification data with an oximeter monitor. | 0 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present patent application/patent claims the benefit of priority of co-pending U.S. Provisional Patent Application No. 62/325,539, filed on Apr. 21, 2016, and entitled “GRADIENT-OPTICAL-INDEX POROUS (GRIP) COATINGS BY LAYER CO-DEPOSITION AND SACRIFICIAL MATERIAL REMOVAL,” the contents of which are incorporated in full by reference herein.
STATEMENT OF GOVERNMENT SUPPORT
[0002] The present invention was made with U.S. Government support by the Naval Research Laboratory, Award No. N0017312-1-G020. Accordingly, the U.S. Government has certain rights in the present invention.
FIELD OF THE INVENTION
[0003] The present invention relates generally to anti-reflective (AR) coatings. More specifically, the present invention relates to systems and methods for producing gradient-optical-index porous (GRIP) coatings by layer co-deposition and sacrificial material removal.
BACKGROUND OF THE INVENTION
[0004] The direct nano-patterning of the surface of an optical element to achieve reduced Fresnel reflections is an attractive alternative to traditional AR coatings. Unlike thin-film multi-layered coatings, this anti-reflective surface structure (ARSS) processing does not involve applying additional materials to the surface of the optics, which often results in coating delamination under thermal cycling and laser damage to the coating at lower thresholds than the window material. In contrast, state-of-the-art processing has resulted in AR performance of ARSSs comparable to that of the traditional AR coatings, while adding significant advantages, such as higher laser damage thresholds, large acceptance angles, and ease of cleaning, since there is no foreign material on the surface. Random ARSSs can be designed to work over large bandwidths with a variety of materials and have been shown to exhibit high laser damage thresholds. The scale of the random pattern utilized is designed to be in the optical sub-wavelength regime in order to avoid undesired diffraction and/or scattering effects, while the height of the individual features is on the order of one-half the optical wavelength in order to simulate a layer with graded index variation, between that of air and the optical substrate. For random-ARSSs (rARSSs), nano-structuring is typically performed using dry-etching-based methods. Lithographic steps are not needed for rARSSs, and the optical surface is typically processed with reactive ion etching, using plasma and gas mixtures appropriate to the substrate material.
[0005] Certain crystalline inorganic materials used for optical applications, such as Sapphire, Germanium, Zinc Sulfide, Zinc Selenide, Calcium Fluoride, and Diamond, have dry (and sometimes wet) etch resistance, as they do not react with etching plasmas, such as Methyl Fluoride, Ethyl Fluoride, Freon, Sulfur-hexafluoride, Oxygen, Chlorine, Boron tri-Chloride, and Hydrogen, or they can react destructively, thus rendering the fabrication of rARSSs impossible with currently known methods and technologies. For these types of optical substrates, there are no rARSSs demonstrated to date. The same applies for polycrystalline and compressed powder substrates, such as various grades of Spinel, Zerodur, and Cleartran. The large index of refraction of these materials (which can vary from 1.5 to 4.0), across their respective application wavelengths (from 150 nm to 20 μm), limits the transmission performance of optical elements and windows fabricated using them. Conventional AR thin-film layered coatings are used to reduce their reflectivity, leading to the issues mentioned previously.
[0006] The ability to fabricate rARSSs on etch-resistant optical substrates would enable the technology to apply beyond vitreous substrates (such as fused silica and glasses), in spectral regions where conventional solutions are currently not available.
BRIEF DESCRIPTION OF THE INVENTION
[0007] In various exemplary embodiments, the present invention provides a specific GRIP layer coating on inorganic optical substrate surfaces, and the fabrication method used to create the GRIP layer coating. The method consists of two major processing steps: (1) the co-deposition of an optical index-matching material and a mass density-modulating material, followed by (2) the sacrificial etch of the mass-density-modulating material to reveal a GRIP surface. The method is designed for use with crystalline, polycrystalline, and dry or wet etch-resistant substrate materials, where AR solutions using ARSSs do not exist. These coatings are designed to minimize Fresnel reflectivity of the original substrate surfaces, using a single porous layer matched to the optical index of the original substrate material.
[0008] In one exemplary embodiment, the present invention provides a method for forming a gradient-optical-index porous anti-reflective coating, comprising: providing a substrate; depositing an optical index matching material on the substrate, wherein an optical index of the optical index matching material is substantially the same as an optical index of the substrate; co-depositing a sacrificial material on the substrate and the optical index matching material to modulate the mass density of the optical index matching material in an intermixing layer between the optical index matching material and the sacrificial material, wherein the intermixing layer has a gradient optical index matching material composition; and etching the sacrificial material and a portion of the intermixing layer to form a porous, random, gradient optical index surface on the substrate. The depositing and co-depositing steps are performed in a vacuum. Optionally, the depositing and co-depositing steps comprise physical deposition steps. In the intermixing layer, the optical index matching material has a higher mass density adjacent to the optical index matching material and the substrate than adjacent to the sacrificial material. The sacrificial material forms a cap layer comprising only sacrificial material adjacent to the intermixing layer. Optionally, etching the sacrificial material and a portion of the intermixing layer comprises randomly etching the sacrificial material and a portion of the intermixing layer. The substrate comprises an inorganic optical substrate. More specifically, the substrate comprises one of a crystalline, a polycrystalline, a dry, and a wet etch-resistant substrate. Optionally, etching the sacrificial material and a portion of the intermixing layer comprises ion-etching the sacrificial material and a portion of the intermixing layer. Optionally, the optical index of the optical index matching material is substantially different from an optical index of the sacrificial material.
[0009] In another exemplary embodiment, the present invention provides a gradient-optical-index porous anti-reflective coating formed by a process, comprising: providing a substrate; depositing an optical index matching material on the substrate, wherein an optical index of the optical index matching material is substantially the same as an optical index of the substrate; co-depositing a sacrificial material on the substrate and the optical index matching material to modulate the mass density of the optical index matching material in an intermixing layer between the optical index matching material and the sacrificial material, wherein the intermixing layer has a gradient optical index matching material composition; and etching the sacrificial material and a portion of the intermixing layer to form a porous, random, gradient optical index surface on the substrate. The depositing and co-depositing steps are performed in a vacuum. Optionally, the depositing and co-depositing steps comprise physical deposition steps. In the intermixing layer, the optical index matching material has a higher mass density adjacent to the optical index matching material and the substrate than adjacent to the sacrificial material. The sacrificial material forms a cap layer comprising only sacrificial material adjacent to the intermixing layer. Optionally, etching the sacrificial material and a portion of the intermixing layer comprises randomly etching the sacrificial material and a portion of the intermixing layer. The substrate comprises an inorganic optical substrate. More specifically, the substrate comprises one of a crystalline, a polycrystalline, a dry, and a wet etch-resistant substrate. Optionally, etching the sacrificial material and a portion of the intermixing layer comprises ion-etching the sacrificial material and a portion of the intermixing layer. Optionally, the optical index of the optical index matching material is substantially different from an optical index of the sacrificial material.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The present invention is illustrated and described herein with reference to the various drawings, in which:
[0011] FIG. 1 (top row) shows refractive index profiles for three cases of interference between materials A and B—(left) a discontinuous single boundary, where the index changes abruptly from nA to nB, (middle) a four-layer coated surface, with intermediate index values, and (right) a gradient-index layered interface; and (bottom)—the physical layout of the materials and boundary regions corresponding to the index cases provided above;
[0012] FIG. 2 shows one exemplary embodiment of the four sequential steps used to form the GRIP layer coating of the present invention on an inorganic optical substrate surface, including: (a) physical vapor deposition of the optical index-matching material on the substrate; (b) physical vapor co-deposition of the optical index-matching material and the sacrificial material; (c) ending the physical vapor deposition cycle with a sacrificial material cap; and (d) sacrificial etching of the material using reactive-ion plasma in a vacuum; and
[0013] FIG. 3 shows: (a) a micrograph of a typical rARSS fabricated using the methods of the present invention (the top insert is a high-magnification electron-microscope image with the nanostructured random surface being partially shown); and (b) optical test results from sequentially deeper etching of the sacrificial layer, forming the GRIP effect (the more sacrificial material is removed, the higher the transmission of the substrate becomes, with the original transmission shown in black)—note, the material used is Spinel, which has a high resistivity to direct reactive-ion-etch.
DETAILED DESCRIPTION OF THE INVENTION
[0014] The present invention is based on the AR properties of a randomly structured optical surface. The goal of the present invention is to significantly reduce the Fresnel reflections created by the boundary discontinuity between an optical substrate and the surrounding medium, which is air, for example. The novelty is in the surface structure fabrication, which is applicable to etch-resistant materials.
[0015] Gradient-index interfaces are used as spectral filters, broad-band AR (BBAR) coatings, and polarization insensitive coatings, for example. The optical function response corresponds to the optical index profile, and the fabrication of the optical index layer(s) is achieved using the following exemplary methods:
(a) Oblique-Angle and Glancing-Angle Sputtering or Physical Vapor Deposition (GLAD), (b) Sputtering or Physical Vapor Co-Deposition (PVD), (c) Dynamic Plasma Reactive Ion Etching or Inductively Coupled Plasma Reactive Ion Etching in a Vacuum (ICP/RIE), (d) Wet Chemical Etching or Leaching, (e) Sol-Gel Deposition and Structuring, (f) Layer-by-Layer Nanocomposite Aqueous Deposition, and (g) Growth of Nano-Rods, Nano-Wires, or Other Nanostructures.
[0023] These fabrication techniques can be grouped in larger categories, such as:
(i) Physical Deposition of Material(s) on the optical substrate (a and b), (ii) Substrate Material Removal (c and d), (iii) Chemical Deposition (e and f), and (iv) Surface Growth at the nanometer scale (g).
[0028] The present invention addresses anti-reflectivity for materials that are resistant to fabrication technique (ii), produce weak or fragile coatings using fabrication techniques (i), (iii), and (iv), and are used in optical component applications, from the ultraviolet (UV) (200 nm) to the long-wavelength infrared (LWIR) (20 μm), for example.
[0029] Optical components for optical beam delivery systems include lenses, prisms, optical flats, windows, beam-splitters, waveplates, polarizers, and filters. In all cases, the light wavefront crosses interfaces between media that are planar and/or curved. All physical boundaries between materials act as optical interfaces. The effects that are observed as a light beam of certain dimensions and with certain intensity crosses an interface could be scattering, diffusion, reflection, absorption, and/or transmission. In real applications, a combination of all of the above is observed to a certain degree. The collective macroscopic physical quantity used to describe the optical mismatch between materials across interfaces is the difference in optical refractive index. The optical admittance between two media separated by a boundary (i.e. interface) is the product of the refractive index and the cosine of the direction of the beam with respect to the boundary. In cases of polarized light beams, the admittance is different for different polarization directions with respect to the boundary normal. As the optical beam crosses the boundary, the boundary effects mentioned above will influence the propagation of the wavefront and the transfer of light intensity. In general, optical path components are engineered to transfer a light beam in specific directions, with minimal losses. Considering that goal, any deviation of the optical beam from the desired direction, or any change induced in the uniformity or intensity of the beam, as it crosses boundaries can be classified as a loss. Scattering in the forward and reverse incident directions, as well as diffuse scattering are considered losses.
[0030] In many cases, in order to suppress a boundary crossing effect, material interfaces are layered. One such example is the multi-layered interference coating, used to create high-reflectivity components, or nullify reflectivity altogether (i.e. an AR coating (MLAR)). In such a case, the collection of refractive indices of the layers making up the interface is used as an interference filter that can constructively add (or subtract) lightwave contributions as the wavefront propagates through it. Deposition of these layers results in some thermal and mechanical defects and moduli mismatches between the layers themselves and between the layers and the substrate. These defects, caused by the deposition fabrication processes, can increase scattering and redistribute the thermal loading in the coatings. The combination of absorption and material inhomogeneities, or structural defects (e.g. scratches, voids, inclusions, and impurities), are the major contributors to laser damage in optical components, and they are central to the lowering of the damage thresholds of interfaces.
[0031] One solution to the minimization of the specular reflection and coherent addition of the fields at the boundaries is the introduction of a gradient-refractive-index interface. Replacing a multilayered coating stack by a gradient-index profile layer has also shown higher damage thresholds in a variety of materials. The principle is illustrated in FIG. 1 . The interface layer at the boundary of two optical materials can be engineered to have a gradual refractive index change, resulting in a continuous index value increase (or decrease). This index profile reduces the specular reflectivity over a large spectral range of wavelengths. There are numerous methods to fabricate gradient-index interfaces. In general, they can be divided into two major categories: deposition techniques and etching techniques, outlined as (a) through (g) above.
[0032] The fabrication technique of the present invention consists of a hybrid method of deposition and etching, using a specific sacrificial layer as a mass density modulator, in order to create a randomly structured surface on a process-incompatible substrate, which in turn will have a gradient-optical-index effect on incident light. The major steps of the fabrication technique are shown in FIG. 2 . In detail, the steps include:
[0033] (A) The deposition of the optical-index matching material on the substrate is performed first under high-vacuum conditions. This deposition can be achieved by physical methods (i.e. sputtering, electron beam evaporation, thermal evaporation, etc.). The purpose of the deposition is to cover the etch-resistant surface with a layer of material that has the same (or close to the same) optical index as the substrate, and allow adhesion to the substrate. For the materials mentioned, the following may be used:
[0000]
Optical substrate material
Optical-index matching layer material
Sapphire, Spinel
Aluminum Oxide
Germanium
Germanium Oxide
Zinc Sulfide, Zinc Selenide
Zinc Oxide
Calcium Fluoride
Silica
Diamond
Amorphous Diamond
[0034] (B) Without removing the substrate from the vacuum chamber, a second physical vapor deposition source can be activated to modulate the mass density of the depositing optical-index matching material with a compatible sacrificial material. During this step, the deposition of the original material (from step (A)) is reduced according to specific schedules in order to enrich the layer mixture with sacrificial material. The purpose of this step is to disrupt the ordered deposition of the index-matching layer, and induce a randomized mixture that will progressively become deprived of the index matching material. The deposition thus creates an intermixing region, which can be engineered to the desired depth parameter requirement. The sacrificial material is chosen for its etching and physical vapor deposition disruption properties only, without any optical-index matching requirements or considerations.
[0000]
Index matching material
Sacrificial intermix material
Aluminum Oxide
Silicon Monoxide
Germanium Oxide
Silicon
Zinc Oxide
Indium Tin Oxide
Silica
Silicon Monoxide
Amorphous Diamond
Silicon Monoxide
[0035] (C) Continuing the sacrificial material deposition after the original optical-index matching material deposition is terminated results in sealing the co-deposition layer with sacrificial material only. This step is required as an end to the co-deposition (intermixing) process.
[0036] (D) Reactive-ion etch (RIE) or Inductively-Coupled RIE (ICP/RIE) is the next step in the fabrication process. The target of this etch step is the removal of the sacrificial top-layer and the intermixed sacrificial material, leaving behind a porous, random, gradient optical-index surface, consisting only of the original optical-index matching material on the substrate. The random depth and density of the remaining layer will introduce gradient-index optical effects on the substrate boundary, leading to the suppression of Fresnel reflection losses, absorption, and scatter.
[0037] The above described method has been demonstrated with specific materials, and a representative example is described herein below.
Example
[0038] Spinel optical grade planar substrates were coated with aluminum oxide (the index matching material) and silicon monoxide (the sacrificial layer) using the fabrication steps described above. The presence of a material intermix region between the aluminum oxide and the silicon monoxide was verified by optical variable angle spectroscopic ellipsometry. Various co-deposition recipes were attempted and verified. The etching step was performed with a RIE chamber using a mixture of sulfur-hexafluoride and oxygen plasma under vacuum. The sacrificial etch was performed with fixed time intervals and the samples were removed and measured. The measurements included: (a) surface profiling under UV-confocal microscopy (LEXT) and Scanning Electron Microscopy (SEM) and (b) optical transmission spectral measurements using a dual-beam spectrophotometer. FIG. 3 shows representative results from the trials. Nano-porosity was verified in control samples of silicon and silica as well. FIG. 3 shows the evolution of the optical gradient-index effect as a function of sequential etches. The transmission of the Spinel substrate was increased by a net 5-7% across the spectral range from 800 nm to 1200 nm. For a single-sided AR-coated Spinel substrate, the transmission enhancement was around 7%. Thus, the results achieve maximum anti-reflectivity at a 100 nm band between 800 nm and 900 nm wavelength.
[0039] Thus, the present invention provides the micro-fabrication of an inorganic, hard, porous coating (GRIP) on optical substrates and components that performs as a gradient-index optical filter, based on a dual deposition and sacrificial etching process, for use from the UV to the IR spectral region.
[0040] The GRIP provided is achieved with a novel fabrication process that leverages the sacrificial material two ways: (a) to induce a random mass-density modulation of the index matching deposition and (b) to allow the removal of the sacrificial material in order to result in a random structured surface with specific optical function properties, such as the suppression of reflectivity. The novel process enables the fabrication of AR surfaces on etch resistant substrates that have no current fabrication solutions, other than conventional multilayered thin film coatings.
[0041] As contemplated herein, the optical index of the optical index matching material is substantially the same as the optical index of the substrate. By way of example only, in the case of a sapphire crystal or synthetic (extraordinary optical index=1.7478, ordinary optical index=1.7557, at a wavelength of 1.0 μm) and aluminum oxide films (optical index=1.7200, at a wavelength of 1.0 μm). Exemplary thicknesses for the optical index matching layer are on the order of the optical wavelength of the application, for the intermixing layer on the order of twice to thrice the optical wavelength of the application, and for the sacrificial layer on the order of the optical wavelength of the application.
[0042] Although the present invention is illustrated and described herein with reference to preferred embodiments and specific examples thereof, it will be readily apparent to those of ordinary skill in the art that other embodiments and examples may perform similar functions and/or achieve like results. All such equivalent embodiments and examples are within the spirit and scope of the present invention, are contemplated thereby, and are intended to be covered by the following non-limiting claims. | The present invention provides a specific gradient-optical-index porous (GRIP) layer coating on inorganic optical substrate surfaces, and the fabrication method used to create the GRIP layer coating. The method consists of two major processing steps: (1) the co-deposition of an optical index-matching material and a mass density-modulating material, followed by (2) the sacrificial etch of the mass-density-modulating material to reveal a GRIP surface. The method is designed for use with crystalline, polycrystalline, and dry or wet etch-resistant substrate materials, where anti-reflective (AR) solutions using AR surface structures (ARSSs) do not exist. These coatings are designed to minimize Fresnel reflectivity of the original substrate surfaces, using a single porous layer matched to the optical index of the original substrate material. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a cryosurgical probe and in particular to a cryosurgical catheter probe for percutaneous employment in a surgical procedure.
2. Description of the Prior Art
Cryosurgical probes are presently in use for freezing body tissue to a degree sufficient to produce a temporary reversible block of electrical conduction through tissue, an inflammatory response, cryo-adhesion or cryo-necrosis. The probe tip is cooled by passing refrigerant (liquid, gas or vapor) at high pressure through a restriction at the tip to cause a loss of pressure with consequent loss of heat and rapid cooling. This phenomenon is commonly known as the Joule-Thomson effect, and is used significantly to reduce the temperature on the exterior surface of the probe tip which is then used for the freezing process.
Such probes are extensively used to freeze external body tissue, and surgically exposed tissue for example in the treatment of skin cancer. However an extension of the use of cryogenic probes for the treatment of internal organs, such as the heart, is now under further active consideration.
In the application of a cryogenic probe to treat the human heart, for example to freeze and destroy aberrant conductive heart tissue, it is necessary to maneuver the probe along the femoral artery from a position in the groin to direct the tip at the end of the probe to the area to be treated.
To achieve this purpose the probe has to be given a steerable capability to enable the surgeon readily to manipulate the probe along the artery to its final destination which necessarily involves a certain amount of twisting or torque being applied over a constantly increasing distance as between the chosen entry to the artery and the probe tip.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a cryogenic probe for percutaneous use which can be guided with safety and precision along arteries of the body to the target area.
According to the invention there is provided a cryosurgical probe comprising a probe head for applying to bodily tissue to be frozen and provided with a cavity, catheter means connected to the probe head for guiding the probe head along an artery of the body, first and second passageways in the catheter leading to said cavity of the probe head, and a restriction in the first passageway such that a refrigerant at high pressure passed therealong suffers cooling after passage through the restriction to cause a reduction in temperature of the probe head, said second passageway being provided to exhaust the cooled refrigerant from said cavity.
Advantageously the probe is provided with a probe handle coupled to the catheter and containing an internal chamber for directing the primary refrigerant flow through the first passageway from a refrigerant inlet, and the exhaust refrigerant flow from the second passageway through a refrigerant outlet.
The first passageway is preferably in the form of a fine stainless steel tube extending axially of the catheter means between the internal chamber in the probe handle and the cavity in the probe head.
A lead wire may be positioned along the length of the catheter means for supporting the stainless steel tube. At the probe head end of the catheter means, the steel tube of the first passageway is coiled around the lead wire to form a heat exchanger. As and cooler exhaust refrigerant in the second passageway formed between the steel tube and the internal walls of the catheter means passes over the coils of the first passageway wound around the lead wire which may be a thermocouple, the cooler exhaust refrigerant further cools the incoming refrigerant in the first passageway to further lower the temperature at the tip of the probe.
In this way some of the waste energy in the exhaust refrigerant may be recovered whereby to improve probe performance especially since the probe may be used to freeze organs with a perfuse warm blood flow.
Advantageously the lead wire may comprise a thermocouple to monitor the tip temperature.
These and other objects of the present invention will be more completely disclosed and described in the following specification, the accompanying drawings and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described by way of example with reference to the accompanying drawings where
FIG. 1 is a view in elevation of a cryogenic catheter probe according to the invention;
FIG. 2 is a view in detail at A of FIG. 1 showing the probe head and catheter connection thereto; and
FIG. 3 is a view in detail at B of FIG. 1 showing the probe handle and catheter connection thereto.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The probe shown in the drawings comprises a probe handle 1, a probe head 2, and a catheter 3 connected at one end to the handle 1 and at the other end to the head 2.
In the example illustrated, the catheter 3 is an angiographic catheter made up of an inner woven Dacron (RTM) core and an outer polyurethane build-up such catheters being available but not exclusively from the Systems Division of the USCI Corporation.
The probe head 2 is a tubular member having a semi-spherical tip 4, with grooves 5 formed in the inner diameter of catheter 3 adjacent tip 4. Other tip 4 shapes may be employed depending on the anatomical procedure in respect of which the probe is being used.
The head 2 is secured in one end of the catheter 3 by means of the grooves 5 and epoxide adhesive engaging the inner walls of the core of the catheter 2, with the tip 4 protruding from the end of the catheter as illustrated in FIG. 2.
A bead of adhesive 6 is used to blend the tip 4 to complete the assembly of the head 2 to the catheter 3, and to allow smooth insertion into the artery when in use.
The other end of the catheter 3 is connected to a probe handle 1 by means of a catheter connection 7.
The catheter connection, see FIG. 3, comprises a central connector element 8 having a head section 9 and a depending tail section 10 separated by a peripheral flange 11 forming forward and rearward peripheral ledges 12 and 13. The depending tail section 10 has a threaded bore 14.
When connecting the catheter 3 to the connector element 8 a bonding agent such as epoxide adhesive is first applied over the catheter 3. The catheter 3 is then screwed into the bore 14 to provide mechanical retention.
Heat shrink tubing 15 is applied around the catheter 3 and tail section 10 to act as a form of strain relief when bending the joint and when torque is applied to steer the catheter 3 with the probe head 2 along an artery of the body.
A tapered cap 16 is secured around the connector element 8 and over the tubing 15.
The peripheral flange 11 is thermally isolated from the tapered cap 16 by insulator ring 17, held against the ledge 12 of flange 11, and the surface of the tail section 10 of the element 8, and abutting the heat shrink tubing 15.
The head section 9 is pneumatically sealed in a refrigerant chamber 18 formed in the handle 1 by `O` ring 19 and mechanically retained with a pin 20. The handle 1 is thermally isolated from the chamber 18 by insulator 21 held between wall 22 of cap 16 and the wall 23 of chamber 18.
The tapered cap 16 is attached to a threaded extension 24 of the main body 25 of handle 1 acting as a secondary retention of connector element 8 in the gas chamber 18. A part of insulator 21 is interposed between the threaded extension 24 and the wall 23 of the chamber 18.
A thermocouple 26, see FIGS. 2 and 3, doubling as a brace to maintain axial alignment of hypodermic tube 27 extends axially along the catheter 3 from the handle 1 to a position protruding a short distance into the probe head 2.
A stainless steel hypodermic tube 27 for delivery of a refrigerant at high pressure to the probe head 2, extends axially of the catheter 3. The tube 27 is linked within the chamber 18 to a refrigerant inlet (not shown) ultimately connected to a refrigerant source (not shown).
As illustrated in FIG. 2, tube 27 is positioned against the thermocouple 26 and coiled around the same near the probe head 2, over a predetermined extent to form a heat exchanger section 28 between the coils of tube 27 and cooled exhaust refrigerant whose purpose will be explained further hereinbelow.
A short rectilinear length 29 of the tube 27 leads from the heat exchanger section 28 to terminate in the cavity 4' of the tip 4. The tube length 29 is provided with a restriction (not shown).
The axially extending space between the thermocouple 26 and tube 27 and the inner walls of the catheter 3, forms a passageway 30 for exhaust refrigerant passing from the cavity 4' to an exhaust refrigerant outlet at the rear end of the handle 6.
In operation high pressure liquified gas such as CO or NO is delivered to the cavity 4' of the probe tip 4 by way of the tube 27. As the refrigerant passes through the restriction formed in the tube length 29 it undergoes Joule-Thomson cooling whereby to effect a significant reduction in temperature on the semi-spherical tip 4 of the probe head 2.
The exhaust refrigerant is then passed to the outlet through the passageway 30 and as it does so passes over the heat exchanger section 28 whereby it cools the incoming refrigerant passing through the heat exchanger coils of tube 27 coiled around thermocouple 26, thus reducing the tip temperature still further by reducing the temperature of incoming refrigerant in tube 27.
Freezing of the tip 4 as described above, is carried out after insertion of the probe head 2 to the required target area within the human body, the flexible catheter 3 permitting the head 2 to be steered to the target area without excessive strain being imposed upon the connections between the catheter and handle 1, and probe head 4.
According to the provisions of the Patent Statutes, I have explained the principle, preferred construction and mode of operation of my invention and have illustrated what I now consider to represent its best embodiments. However, it should be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically illustrated and described. | A cryosurgical probe having a probe head which is cooled by Joule-Thomson cooling, and is then used to freeze bodily tissue during a surgical procedure. A steerable catheter is connected between the probe head and a probe handle to enable the probe head to be guided with safety and precision along arteries of the body to the target area. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention generally relates to hitches for coupling trailers and the like to towing vehicles such as trucks, automobiles and the like, and more particularly to an improved trailer hitch characterized by a coupling arm which facilitates an expeditious coupling of a trailer with a non-aligned towing vehicle.
2. Description of the Prior Art
In the prior art, of course, it is well recognized that difficulty often is encountered in mating opposed portions of a hitch and the like in the event a non-aligned combination for the portions is in operation encountered. The prior art includes numerous devices particularly adapted for use in coupling a trailer, herein referred to as a towed vehicle, with a powered vehicle, herein referred to as a towing vehicle, even though a non-aligned condition exists for the vehicles, and then the opposed portions of the hitch being employed. Typifying such hitches are those disclosed in U.S. Letters Pat. Nos. 3,912,119; 3,126,210; and 3,266,818. However, even though the hithces of the prior art tend to function quite satisfactorily for their intended purposes, it is noted that designers of hitches continuously seek to reduce cost and complexity while increasing utility and reliability of the hitches.
It will, of course, be fully appreciated that in order to increase the utility of a hitch it is highly desirable to increase the ease with which the hitch is used in coupling a towed vehicle to a towing vehicle. Additionally, it is important that a sacrificing of cost reduction and reliability simply to increase the ease with which the hitch is employed be avoided where possible.
It is, therefore, the general purpose of the instant invention to provide an improved hitch characterized by a pivotal coupling arm for accommodating vehicle non-alignment and an improved mechanism for arresting motion of the arm, whereby utility of the hitch is enhanced without sacrificing cost and reliability.
OBJECTS AND SUMMARY OF THE INVENTION
It is, therefore, an object of the instant invention to provide an improved hitch for a towed vehicle.
It is another object to provide in a hitch characterized by a pivotal coupling arm an improved mechanism for capturing the arm and thereafter supporting the arm in a retracted, towing configuration.
It is another object to provide in a hitch characterized by a displaceable coupling arm responsive to the motion of the arm for capturing the arm and supporting it in a retracted towing configuration.
Another object is to provide an improved hitch adapted to be mounted on a towed vehicle for connecting the towed vehicle to a non-aligned towing vehicle, although not necessarily restricted in use thereto since the hitch can be employed equally as well when mounted on the towing vehicle and employed for connecting the towing vehicle to a non-aligned towed vehicle.
These and other objects and advantages are achieved through the use of a hitch characterized by an arm supported by a pin-and-slot coupling for pivotal displacement as well as rectilinear displacement between extended and retracted dispositions, and means for securing the arm against displacement including a bolt receiver comprising a bore defined in the arm adjacent to the slot, and a locking bolt disposed in coaxial alignment with the bore when the arm is in a retracted position, a cam follower surface defined in the arm for engaging the bolt as the arm is retracted, whereby the arm is positioned for establishing coaxial alignment between the bore and the bolt, and a bolt actuator for driving the bolt into the bore as coaxial alignment occurs, as will become more readily apparent by reference to the following description and claims in light of the accompanying drawings.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a hitch which embodies the principles of the instant invention having a coupling arm depicted in an extended disposition.
FIG. 2 is a top plan view of the hitch depicting alternate pivotal positions for the arm.
FIG. 3 is a partially sectioned, fragmented side elevational view of the hitch illustrating the arm in its extended disposition.
FIG. 4 is a partially sectioned, fragmented, side elevational view illustrating the arm in its retracted disposition.
FIG. 5 is a fragmented top plan view of a portion of the hitch illustrating the effect of positioning means provided for maintaining alignment of the arm as a retraction thereof occurs.
FIG. 6 is a top plan view of the hitch illustrating the arm in a retracted, towing configuration.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings wherein like reference characters designated like or corresponding parts throughout the several views there is shown in FIG. 1 a hitch, generally designated 10, which embodies the principles of the instant invention.
The hitch, as shown in FIG. 1, includes a bottom plate 12 configured to be received at the leading end of a trailer or similar towed vehicle. As illustrated, the bottom plate 12 is configured to be mounted at the apex of a conventional A frame of the type frequently provided for so called house trailers, mobile homes and the like. However, it should be apparent that the bottom plate 12 is configured to be mounted on the tongue of conventional trailers, and, where desired, on the bumpers of towing vehicles such as pickup trucks and the like. Therefore, the particular configuration of the bottom plate 12 is dictated, at least in part, by the environment in which the hitch is to be employed and is varied as desired.
However, it is important to note that the hitch 10 also includes a cover plate 14 of a truncated triangular configuration. The cover plate 14, as shown, is of an integrated construction and includes downturned or vertical side walls 16 extended in converging directions. Between the side walls, between adjacent ends thereof, there is formed a first throat 18 and a second throat 20. The throat 20 is characterized by a width dimension greater than the dimension of the first throat 18.
Projected from the first throat 18 there is a coupling arm 22 having a ball-hitch receiver 24 disposed at its extended end. Again, it is to be understood that while a ball-hitch receiver is shown, it can readily be appreciated that the particular configuration of the receiver is varied as desired. For example, a clevis can be provided at the extended end of the coupling 22, where so desired, without departing from the spirit of the invention.
It is important to note that, as best illustrated in FIG. 6, the coupling arm 22 is supported to be extended to a coupling configuration and subsequently retracted to a towing configuration. Moreover, the arm 22 is of a length such that it projects from the first throat 18 as well as the second throat 20 when the arm is fully retracted to its towing configuration. Consequently, the width dimension of the coupling arm 22 is slightly less than the width dimension of the throat 18 whereby extension and retraction of the arm relative to the throat is accommodated.
Extended along the center portion of the coupling arm 22 is a slot 26, best illustrated in FIG. 2. The slot 26 includes a linear segment 28 which terminates in a cylindrical bore 30 for thus imparting thereto a keyhole configuration.
With particular reference to FIGS. 3 and 4, it can be seen that the coupling arm 22 is connected to the plates 12 and 14 through a use of a spring-loaded pin assembly, generally designated 32. The pin assembly 32, as shown, includes a segmented, axially displaceable shaft having a first segment comprising a retainer pin 34 and a second segment comprising a locking bolt 36 of a cylindrical configuration. As shown, the retainer pin 34 is of a diameter slightly less than the diameter of the segment 28 of the slot 26, while the locking bolt 36 is characterized by a diameter somewhat greater than the diameter of the retainer pin but slightly less than the diameter of the bore 30. Consequently, the retainer pin 34 is afforded passage through the keyhole slot 26, along the entirety of its length, while passage of the locking bolt 36 through the arm is limited to the bore 30, as best illustrated in FIGS. 3, 4 and 5.
At this juncture, it is important to appreciate that the retainer pin 34 affords pivotal displacement of the arm 22 as well as to function as a guide for the arm as it is extended and retracted relative to the throats 18 and 20. Additionally, the retainer pin 34 serves to afford a coupling of a helical compression spring 38 to the pin assembly 32 for purposes of imparting a spring-load thereto. The spring 38 is concentrically related to an end portion of the retainer pin 34 and is interposed between a keeper 39 affixed to the pin 34 and the bottom surface of the plate 12. Hence, it should be appreciated that the spring 38 continuously applies a retracting force to the retainer pin 34 for continuously urging the pin downwardly, as viewed in the drawings.
It is also important to note that between the adjacent segments of the shaft forming the retainer pin 34 and the locking bolt 36 there is an annular surface 40 extended radially relative to the longitudinal axis of the locking bolt. The annular surface 40, in effect, functions as a bearing surface for restraining the locking bolt 36 from displacement in response to the applied forces of the spring 38. Thus, the annular surface 40 simply slides along the top surface of the arm 22 as the coupling arm 22 is displaced. As a practical matter, to the upper extremity of the locking bolt 36, as viewed in the drawings, there is a T-handle 42 which permits the locking bolt 36 to be elevated against the applied forces of the spring 38. The purpose of accommodating elevational displacement of the locking bolt is to accommodate a release of the arm 22, as will hereinafter become more readily apparent.
As best shown in FIGS. 3 and 4, the cover plate 14 is provided with a cylindrical aperture 44 through which the locking bolt 36 projects. The diameter of the aperture 44 is slightly greater than the diameter of the locking bolt 36 whereby the surfaces of the aperture serve to guide the locking bolt as reciprocating motion is imparted thereto.
As should now be apparent, as the coupling arm 22 is retracted toward its towing configuration, illustrated in FIG. 6, the inner surfaces of the side walls 16 engage the adjacent end of the coupling arm 22 and urge it toward the center-line of the throat 18. Thus the coupling arm is caused to pass through the throat 18, as retracting displacement is imparted thereto. Simultaneously, the retainer pin 34, as it is centered with the slot 26, serves as a centering pin for the trailing portion of the arm 22 as the arm is retracted, relative to the throat 20.
Continued retraction of the arm 22 to a fully retracted towing configuration, of course, causes the bore 30 to move toward alignment with the locking bolt 36. However, in order to assure that coaxial alignment is achieved between the bolt 36 and the bore 30, the upper surface of the arm 22 is provided with a camming relief 46. This relief is of a diameter substantially equal to the diameter of the locking bolt 36 and includes a curved wall surface 48, FIG. 5, generally symmetrically related to the slot 26 and terminates in the surfaces of the bore 30. Additionally, the relief 46 is provided with a bottom bearing surface 50 upon which the annular surface 40 is permitted to ride once the locking bolt 36 is caused to enter the relief 46 under the influence of the spring 38.
The curved surface 48, as depicted in FIG. 5, rides against the cylindrical surface of the locking bolt 36 and thus the mated surfaces of locking bolt 36 and the relief 46 function as cam and cam follower surfaces for purposes of assuring that coaxial alignment is established between the bore 30 and the locking bolt 36 as the coupling arm 22 is retracted into a fully retracted towing disposition. Of course, once coaxial alignment is achieved between the locking bolt 36 and the bore 30 the spring 38, acting against the keeper 39, causes the locking bolt 36 to advance into a fully seated relationship with the bore 30. Thus the coupling arm 22 is secured against linear displacement, relative to the plates 12 and 14 of the hitch, until the locking bolt 36 is extracted from the bore 30 for effecting a release of the arm 22. In order to extract the bolt 36 from the bore 30, and thus release the arm 22 for displacement, the T-handle 42 is grasped and the locking bolt 36 lifted from the bore 30 in a simple manual operation.
OPERATION
It is believed that in view of the foregoing description, the operation of the hitch 10 will readily be understood and it will be briefly reviewed at this point.
With the hitch 10 assembled in the manner hereinbefore described, and mounted at the forward end of a towed vehicle, such as a house trailer or the like, the ball-hitch receiver 24 is readily positioned to receive the ball, not shown, of a ball-hitch mounted on a towing vehicle, such as on the bumper of a pickup truck, automobile or the like. Such positioning of the receiver 24 is facilitated due to the fact that pivotal motion and axial extension of the arm 22 is accommodated as the retainer pin 34 is permitted to advance, relative to the slot 26. Of course, so long as the annular surface 40 of the locking bolt 36 rides along the upper surface of the coupling arm 22 the arm 22 may be extended, retracted and/or pivotally displaced in directions suitable for positioning the receiver 24 to receive the ball of the ball-hitch. Once the receiver 24 is positioned to receive the ball of the ball-hitch the ball is inserted into the receiver in a conventional manner. The operator of the towing vehicle now moves the towing vehicle in a direction such that the arm 22 is forced to move in a retracting direction, relative to the hitch 10. As retraction of the arm 22 occurs, the side wall 16 of the hitch forces the arm 22 toward a coaxial aligned relationship with the first throat 18, while the opposite end of the arm 22 is centered by the retainer pin 34 riding in the linear segment 28 of the slot 26.
Continued retraction of the arm 22 causes the relief 46 to be positioned beneath the annular surface 40 of the locking bolt 36. Once this positional relationship is established between the relief and the locking bolt, the locking bolt 36 "drops" into the relief 46 whereupon the annular surface 40 of the bolt is permitted to ride along the curved surface 48 of the relief. As additional retraction is imparted to the coupling arm 22 the surfaces of the relief and the locking bolt cooperate to guide the arm in a manner such that coaxial alignment is established between the bore 30 and the locking bolt 36.
Once coaxial alignment is achieved between the bore 30 and the locking bolt 36 the spring 38 of the spring-loaded pin assembly 32 acting on the locking bolt 36, through the pin 34, draws the locking bolt 36 into the bore 30 for thus establishing the coupled relationship with the locking bolt and arm 22. Additionally, it should be appreciated that the end portion of the coupling arm 22 extended through the throat 18 is confined against pivotal displacement due to an engagement thereof by the side walls 16. Hence, the coupling arm 22 achieves a substantially fixed relationship with the plates 12 and 14 and the coupling arm 22 is thus secured in its towing configuration. Release of the locking pin 36, relative to the coupling arm 22, is achieved simply by grasping the T-handle 42 and lifting the locking bolt through a distance sufficient to extract the locking bolt from the bore 30, whereby the arm 22 is released for both pivotal and axial displacement.
In view of the foregoing, it should readily be apparent that the hitch 10 provides a practical solution to the problem of achieving increased utility, efficiency and reliability for hitches particularly suited for use in coupling house trailers and the like with towing vehicles such as pickup trucks, automobiles and the like.
Although the invention has been herein shown and described in what is conceived to be the most practical and preferred embodiment, it is recognized that departures may be made therefrom within the scope of the invention, which is not to be limited to the illustrative details disclosed. | A hitch for use in coupling a trailer to a towing vehicle characterized by a housing having bottom and top plates disposed in mutually spaced parallelism and a pair of converging side walls defining on opposite sides of the housing a first and a second throat disposed in coaxial alignment, said first throat being of a width dimension less than the width dimension of the second throat, an extensible link comprising a coupling arm seated between said plates having a width dimension slightly less than the width dimension of the first throat and projected from the second throat, a slot of a keyhole configuration comprising an elongated segment terminating in a bore, a retainer pin normally related to the plates and extended through the slot supporting the link for displacement to a retracted position wherein said link is extended through the first throat, and a cylindrical interlocking bolt integrally related to the retainer pin and configured to be inserted into the bore when the link is displaced to its retracted position for securing the link against displacement from its retracted position, whereby the link is supported against both axial and pivotal displacement. | 1 |
CROSS-REFERENCE TO RELATED APPLICATION
This application incorporates by reference, and claims priority to, and the benefit of, German patent application serial number 19904744.8, which was filed on Feb. 5, 1999.
TECHNICAL FIELD
The invention relates to an article of footwear with a sole that includes a stability element to control, in a pre-selected manner, the rotation of the forefoot area with respect to the rearfoot area of the article of footwear.
BACKGROUND INFORMATION
The processes in the human foot during walking or running are enormously complex. Between the first contact of the heel and the push-off with the toes, a number of different movements take place throughout the entire foot. During these movements, various parts of the foot move or turn with respect to each other.
It is an objective in the construction of “normal” footwear, to obstruct these natural movements, such as they occur in barefoot running, as little as possible and to support the foot only where it is necessary for the intended use of the footwear. In other words, the objective is to simulate walking or running barefoot.
In contrast thereto, it is an objective of orthopedic footwear to correct malpositions or orthopedic deformities of the foot, for example, by reinforcing the material in certain parts of the sole to provide additional support for the foot. The present invention, however, focuses on the construction of footwear for “normal” feet, though it may be useful in other applications.
In this context, it was already realized in the past that the classical outsole, which extends over the entire article of footwear, does not meet the above mentioned requirements. In particular, rotations of the forefoot area around the longitudinal axis of the foot with respect to the rearfoot area (referred to in physics as torsional movements) are, at the least, considerably hindered by a homogeneously formed, continuous outsole or arrangement of soles.
To overcome these difficulties, stability elements were developed which supply separate parts of the sole with a controlled rotational flexibility, and which define by their form and their material the resistance of the sole against such twisting movements.
One example of a known stability element is disclosed in U.S. Pat. No. 5,647,145. The footwear sole construction described in this prior art approach complements and augments the natural flexing actions of the muscles of the heel, metatarsals and toes of the foot. To meet this objective, the sole comprises a base of resiliently compressible material, a plurality of forward support pads supporting the toes, a plurality of rearward support lands supporting the metatarsals, a heel member supporting and protecting the heel of the wearer's foot, and a central heel fork which overlays and is applied to the heel member. At heel strike, the heel fork tends to help stabilize and hold or reduce the rearfoot from over-supination or over-pronation by guiding and stabilizing the heel bone.
Another embodiment of a known stability element (which is similar to the above described heel fork) is shown and discussed in conjunction with FIG. 14 of the present application. The stability element 10 ′ shown in FIG. 14 is shaped like a bar, a cross, or a V, and starts at the rearfoot area 2 ′ of the sole and terminates in the midfoot area of the sole.
These known stability elements are capable of providing some stability to the various parts of the foot through their rigidity, however, an important disadvantage is that they provide insufficient joint support for the longitudinal and lateral arch of the foot. Compared to an ordinary continuous sole molded to the contour of the foot, stability is considerably reduced.
Furthermore, the arrangement of layers of foamed materials typically used in the forefoot area is relatively yielding so that due to the high impact forces that occur during running the sole yields on the medial or lateral side, and the foot rotates in response thereto by a few degrees to the inside or the outside, particularly if the wearer's foot anatomy tends to support such rotational movements. These rotational movements are known in the art as pronation and supination, respectively, and lead to premature fatigue of the joints of the foot and knee, and sometimes to injuries.
Additionally, a sole with a soft or yielding forefoot area leads to a loss of energy. The deformation of the sole during the push-off phase of the step is not elastic, therefore, the energy used for the preceding deformation of the sole cannot be regained.
It is an objective of the present invention to provide an article of footwear which controls, in a pre-selected manner, the rotation of the forefoot area with respect to the rearfoot area and at the same time supports the forefoot area to avoid excessive pronation or supination, thereby reducing and/or preventing premature fatigue or injuries to the wearer.
According to another aspect of the invention, the footwear sole should store any energy applied during the landing phase and supply it to the course of movements at the correct time during the push-off phase of the foot.
SUMMARY OF THE INVENTION
In one aspect, the invention relates to an article of footwear including a rearfoot portion, a forefoot portion, and a sole with a stability element. The stability element extends from the rearfoot portion into the forefoot portion, and is constructed of a material and configured for controlling, in a pre-selected manner, the rotation of the forefoot portion of the shoe around the longitudinal axis with respect to the rearfoot portion.
The stability element can extend substantially along the medial side of the shoe, or substantially along the lateral side. The stability element can include a forefoot area including material properties for reducing pronation or supination of the wearer's foot.
According to another embodiment, in this case for pronation control, metatarsals one and/or two of the wearer's foot are supported, preferably together with phalanges one and/or two. In the case of supination control, metatarsals five and preferably four are supported, preferably together with phalanges five and/or four.
Due to the extension of the stability element from the rearfoot portion into the forefoot portion where the metatarsals and phalanges are located, the foot is supported over its effective longitudinal length without affecting the flexibility of the footwear with respect to the twisting of the forefoot portion relative to the rearfoot portion. Excessive strain or the breaking of the longitudinal arch of the foot under high stress, for example, the landing after a leap, is effectively avoided. In addition, the stability element supports the front part of the foot in the forefoot area.
A camera using high-speed film photographed the feet of running athletes during a pronation study. The photographs show that footwear with a supported forefoot area effectively avoids the turning of the foot to the medial side. The reason is that the material properties of the stability element in the forefoot area of an article of footwear do not yield on the medial side under higher pressure. Preferred materials for the forefoot area of the stability element have a longitudinal bending strength in the range of approximately 350 N/mm to 600 N/mm and a lateral bending strength of approximately 50 N/mm 2 to 200/mm 2 (measured according to DIN 53452).
According to another embodiment of the invention, the stability element comprises an elastic forefoot plate, or has elastic properties in the forefoot area. During landing of the foot and the subsequent rolling of the toes, the forefoot area is elastically bent. In the subsequent course of the movement, after the rearfoot part has left the ground, the foot is stretched to push-off from the ground. At this moment, the forefoot area of the stability element springs elastically back into its original shape; thereby supporting the push-off from the ground. In this way, the energy invested for the elastic deformation of the shoe is regained and aids the continuation of the movement. The forefoot plate or area preferably shows a stiffness in the range of approximately 50 N/mm to 100 N/mm (measured according to ASTM 790).
According to another embodiment, the stability element includes two parts connected in a V-like shape. This allows precise adaptation to the different forms of both the medial and the lateral side of the longitudinal arch of the foot.
The stability element can include at least one support element at its side. The lateral arch of the foot is specifically supported by the support element(s) of the stability element. The stability element can also include at least one side element which extends upwardly from the side of the stability element over the edge of the footwear. This embodiment is preferred for use in sports with a high lateral strain on the foot.
The above mentioned material properties can be obtained by manufacturing the stability element from a composite material of resin and carbon fibers.
These and other objects, along with advantages and features of the present invention herein disclosed, will become apparent through reference to the following description of embodiments of the invention, the accompanying drawings, and the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings, like reference characters generally refer to the same parts throughout the different views. Also, the drawings are not necessarily to scale; emphasis instead generally being placed upon illustrating the principles of the invention. In the following description, various embodiments of the present invention are described with reference to the drawings which show:
FIG. 1 : A skeleton of a human foot for explaining certain principles of the present invention;
FIG. 2 : An article of footwear according to one embodiment of the invention;
FIG. 3 : Another embodiment of the invention, in particular an article of footwear with a narrower sole;
FIG. 4 : Another article of footwear constructed in accordance with the teaching of the invention and incorporating a stability element including two parts connected in a V-like shape;
FIG. 5 : Another embodiment of the invention with three additional side elements;
FIG. 6 : Another embodiment of the invention wherein the medial and the lateral part of the stability element extend into the forefoot area;
FIG. 7 : A test installation to determine the stiffness of the forefoot plate;
FIG. 8 : Force-deformation characteristics to determine the stiffness of the forefoot plate;
FIG. 9 : Hysteresis loop of the deformation of the sample plate E;
FIG. 10 : Hysteresis loop of the deformation of the sample plate F;
FIG. 11 : Hysteresis loop of the deformation of a planar sample plate;
FIG. 12 : Hysteresis loop of a shaped sample plate;
FIG. 13 a : Results of the pronation measurements with different stability elements;
FIG. 13 b : A schematic drawing for explaining the pronation angle; and
FIG. 14 : A prior art shoe incorporating a V-shaped stability element.
DESCRIPTION
According to one embodiment of the present invention, an article of footwear comprises a stability element, which is arranged beneath the foot of the wearer. This can be achieved by integrating the stability element in accordance with the present invention into the outsole of the article of footwear, or sandwiching it between the outsole and the midsole, or between the midsole and the insole. If the stability element is arranged within the outsole, it may differ in color from the surrounding material of the sole, so that the special form (which is an indication for which sport the corresponding article is intended, as described more fully below) of the stability element can easily be recognized from the outside. According to another embodiment, the outsole itself consists essentially of the stability element. In this case, an optional midsole and an optional insole can be applied to the upper side of the stability element to provide comfort and damping to the wearer of the article.
The above described different possible arrangements of the stability element do not significantly influence the functional properties of the article comprising the stability element in accordance with the present invention, therefore, reference is made in the following (and in the Figures) only to an article of footwear in general.
Before the design and the functional characteristics of the stability element in accordance with the present invention are described in detail, reference is made to the skeleton of a human foot 90 shown in FIG. 1, to facilitate the understanding of the inventive principles with respect to the particular parts of the foot that are selectively supported.
In FIG. 1, reference numeral 92 depicts the metatarsals of a left human foot 90 , and reference numeral 95 depicts the phalanges (toes). Essentially, both the metatarsals 92 and the phalanges 95 form the forefoot part of the foot. The metatarsal-phalangeal joints 93 are located between metatarsals 92 and phalanges 95 . The phalanges 95 include a plurality of interphalangeal joints 96 . During a walking or running cycle, the metatarsal-phalangeal joints 93 and the interphalangeal joints 96 allow the foot to flex and push-off from the ground.
Altogether, there are five metatarsals 92 referred to as the first, second, third, fourth and fifth metatarsals, 92 - 1 to 92 - 5 , moving from the medial side 99 of the foot to the lateral side 98 . Similarly, there are five phalanges, 95 - 1 to 95 - 5 . Finally, the heel bone 91 is depicted.
For a stability element in accordance with the present invention, it is important for the sake of pronation or supination control to appropriately support the phalanges and the metatarsals. In the case of pronation control, metatarsal 92 - 1 and/or metatarsal 92 - 2 is supported, preferably with phalange 95 - 1 and/or 95 - 2 . In the case of supination control, metatarsal 92 - 5 and/or metatarsal 92 - 4 is supported, preferably with phalange 95 - 5 and/or 95 - 4 . The necessary support is provided by a stability element in accordance with the present invention, however, since supination is rarely a problem, and for the sake of conciseness in the following description, only pronation control stability elements are discussed. The present invention is, however, not restricted to this field. Complementary shaped stability elements supporting the respective metatarsals and phalanges for supination control are also covered by the present inventive concept.
One embodiment of a stability element for an article of footwear 1 for a right foot, in accordance with the present invention, is shown in FIG. 2 . The stability element 10 comprises an oblong shape with a rearfoot area 12 and a forefoot area 13 . The stability element 10 extends from the rearfoot portion 2 of the article of footwear 1 into the forefoot portion 3 . As may be derived from FIG. 2, the forefoot area 13 is designed and located within the shoe such that the first and/or second metatarsal of the wearer's foot rests on the stability element, with any necessary additional sole layers therebetween, and are effectively supported. According to a particular embodiment of the invention, the stability element also supports the first and/or second phalange.
Between areas 12 and 13 , the stability element 10 comprises an area 11 with reduced lateral dimensions which allows twisting of the forefoot area 13 of the stability element 10 (and thereby of the footwear) relative to the rearfoot area 12 . The resistance and twisting of the stability element 10 in the area 11 defines the rotational flexibility of the footwear. A defined rotational flexibility can also be achieved by a more elastic material in area 11 .
The above described stability element has several important advantages over the prior art. First, since the stability element 10 extends almost over the complete longitudinal extension of the article of footwear 1 , the longitudinal arch of the foot is effectively supported over its total length. Many injuries which may occur if the arch is overstressed are avoided.
Second, support at the forefoot area of an article of footwear, which is the part subjected to the greatest load during running or walking, is significantly improved. In the embodiments of the invention shown in FIGS. 2 to 4 , the forefoot area 13 of the stability element 10 extends substantially along the medial side of the article of footwear to compensate for excessive pronation, as discussed above.
And last, any twisting movement of the forefoot portion 3 of an article of footwear 1 with respect to the rearfoot portion 2 can be controlled in a pre-selected manner by the shape and the selection of the material of the stability element 10 in area 11 .
To determine the material properties of the stability element in the forefoot area 13 which are well suited to reduce pronation, the foot contacts of running athletes were filmed from behind with a high speed camera taking 200 images per second. These recordings were analyzed to determine the maximum pronation angle of the foot with respect to the material properties of the stability element in the forefoot area. The pronation angle or rearfoot angle is defined as the angle α between a vertical line through the foot and the plane of the ground (see FIG. 13 b ). In a normal position of the foot, this angle is 90°. All measured angles were therefore referenced to this value so that a positive value corresponds to a rearfoot angle of more than 90°, i.e., pronation, and a negative angle corresponds to a rearfoot angle of less than 90°, i.e., supination.
As a result of this study (see FIG. 13 a ), it was found that a stability element 10 with a bending strength in the longitudinal direction, i.e., parallel to the fiber direction (the fibers being aligned with a longitudinal axis of the shoe), between 350 N/mm 2 and 600 N/mm 2 (measured according to DIN 53452), and a bending strength in the lateral direction, i.e., perpendicular to the fiber direction, between 50 N/mm 2 and 200 N/mm 2 successfully reduced the maximum pronation angle of the foot. In particular, bending strengths between approximately 450 N/mm 2 and 500 N/mm 2 and between approximately 90 N/mm 2 and 160 N/mm 2 yielded the best results. Whereas athletes wearing footwear without a stability element (see sample a in FIG. 13 a ) showed a pronation angle of 1.6 degrees, the pronation was considerably reduced (−0.9 and −0.6 degrees, see samples b and c in FIG. 13 a , the error bars indicate statistical errors of the measurements) with athletes wearing footwear equipped with stability elements having the above described material properties.
According to a second aspect of the present invention, the stability element 10 preferably comprises in the forefoot area 13 an elastic forefoot plate which stores energy by elastic deformation during the landing of the foot and releases the energy essentially without any loss during the push-off of the foot from the ground to facilitate and support the course of motion. Although, it would in principle be possible to integrate this forefoot plate into the shoe independent of a stability element, for cost and production it may be advantageous and preferred to combine these two parts. In the described embodiments, the forefoot plate can therefore be invisibly integrated into the forefoot area 13 of the stability element 10 (and therefore not shown in the Figures). According to an alternative embodiment the stability element 10 itself consists of an elastic material to achieve the described energy storing function.
In the following, the forefoot plate or the stability element is further described with respect to its elasticity, which is the necessary precondition for the substantially loss-free storing and release of the energy from the deformation of the plate.
For noticeable support of an athlete during running, in particular during sprints, the forefoot plate should have a stiffness which is both great enough to facilitate the push-off of the foot with the energy that has been stored during the landing, and not so stiff as to undesirably hinder the natural course of motion. Studies with athletes have shown that a stiffness in the range of approximately 50 N/mm to 100 N/mm is best suited to meet these requirements. The stiffness was measured with an ASTM 790 test installation as shown in FIG. 7 and described in the following.
To this end, a 250 mm long and 50 mm wide sample plate 200 of the material to be tested is symmetrically positioned on two 80 mm distant support points 310 . Subsequently, the sample plate is deformed with the vertical force which acts upon the sample plate in the center (vertical arrow in FIG. 7 ). In this way, the deformation of the sample plate depending on the force can be measured with a dynamometer. FIG. 8 shows results of measurements of sample plates with varying stiffnesses. The stiffness is the gradient of the curve in the linear range, i.e., the range of small deformations. For application as a forefoot plate, a stiffness between approximately 50 N/mm (sample plate F) and approximately 100 N/mm (sample plate E) is preferred.
Another important criteria for a forefoot plate is elasticity, i.e., whether the force necessary for the deformation can be regained when the plate springs-back into its original shape. FIGS. 9 to 12 show hysteresis loops of different sample plates, each with a stiffness between approximately 50 N/mm and 100 N/mm. To measure these loops, the force was measured by cyclically deforming and releasing the sample plates in the above described test installation (FIG. 7 ), where the time for one cycle was 200 milliseconds. The difference between the upper and lower line, i.e., the area enclosed by the two lines, is representative of the loss of elastic energy during the deformation of the sample plates.
It follows from the curves in FIGS. 9 to 11 that the energy loss in the planar shaped sample plates of the above mentioned stiffness is between 4.6% and 6%, i.e., a major part of the energy is regained during the spring-back into the original shape. FIG. 12 shows a hysteresis loop for a sample plate that was not planar shaped. The significantly greater energy loss of this plate, 18.3%, is shown in FIG. 12 . The forefoot plate according to the invention is, therefore, preferably planar.
With respect to the shape of the stability element 10 , additional support elements 15 can be arranged at the side in the forefoot area 13 as well as at the rearfoot area 12 , which extend essentially laterally with respect to the longitudinal axis of the foot, as shown in FIGS. 2 and 3. The support elements 15 extend the supporting effect of the stability element 10 into the lateral and medial side parts of the article of footwear 1 to enhance protection of the lateral arch of the foot against excessive strain. The extension of the side elements 15 depends on the shape of the article of footwear. FIG. 3 shows an embodiment for a narrower article of footwear, where the supporting elements 15 are correspondingly shorter.
In a further embodiment of a stability element, as shown in FIG. 4, the stability element 10 comprises two parts, 20 and 30 , which form a V-like shape. Part 30 supports the medial part and part 20 the lateral part of the longitudinal arch of the foot. The connection of the two parts, 20 and 30 , in rearfoot area 12 of stability element 10 allows, (in contrast to a “normal” continuous sole) for twisting around area 11 , and relative movement of the two parts, 20 and 30 , with respect to each other.
In the embodiments of stability elements shown in FIGS. 5 and 6, the medial part 30 of the stability element 10 comprises notches 31 and holes 32 to increase the flexibility of the stability element in the forefoot portion 3 in the lateral direction. The embodiment shown in FIG. 5 is optimized for sports where the foot is not subjected to extreme lateral stress; for example, track-and-field athletics, jogging, etc. Support of the lateral half of the foot is, therefore, only necessary in the midfoot area so part 20 is designed correspondingly shorter then part 30 . In the embodiment shown in FIG. 6, the lateral part 20 , as well as the medial part 30 , extends into the forefoot portion 3 of the article of footwear. This embodiment, in particular, is used in sports with many changes of direction and many sideways steps; for example, tennis, basketball, etc. The elongated part 20 in this case serves to support the lateral side of the forefoot against the high strain resulting from these movements.
In the embodiment shown in FIG. 5 and FIG. 6, additional side elements 40 are provided to increase the stability of the connection between the stability element 10 and the surrounding material of the article of footwear in the area 11 by sideways and upwardly encompassing the article of footwear. In the embodiments shown, side elements 40 are provided on the medial side of the article of footwear, an arrangement on the lateral side is also possible and in particular useful for further reinforcement of the lateral side in the above mentioned sports like tennis, basketball, etc.
As material for the stability element and the integrated forefoot plate, preferably a composite material of carbon fibers embedded into a matrix of resin is used. Other suitable materials include glass fibers or para-aramid fibers, such as the Kevlar® brand sold by DuPont. These materials combine good elasticity values with low weight. Also, steel or other elastic metal alloys could be used in particular for the forefoot plate. Suitable plastic materials include thermoplastic polyether block amides, such as the Pebax® brand sold by Elf Atochem, and thermoplastic polyester elastomers, such as the Hytrel® brand sold by DuPont. Plastic materials have advantages with respect to production by injection molding, however, the necessary elastic properties can only be obtained through additional reinforcement with fibers. Other suitable materials will be apparent to those of skill in the art.
Having described embodiments of the invention, it will be apparent to those of ordinary skill in the art that other embodiments incorporating the concepts disclosed herein may be used without departing from the spirit and the scope of the invention. The described embodiments are to be considered in all respects only as illustrative and not restrictive. Therefore, it is intended that the scope of the present invention be only limited by the following claims. | An article of footwear including a sole with a stability element constructed of a material and configured for controlling, in a pre-selected manner, the rotation of the forefoot portion of the article of footwear around the longitudinal axis with respect to the rearfoot portion. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority in U.S. Provisional Patent Application No. 61/213,929, filed Jul. 30, 2009, which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present disclosed technology relates generally to a rolled door installation device, and in particular a cradle for holding a rolled curtain door and a system for installing the door above an opening.
2. Description of the Related Art
Curtain door systems for residential and commercial use provide a movable barrier to cover a window or opening in a wall. The door systems may be manufactured to cover windows or openings having a wide variety of widths and heights. Curtain door systems are used in a variety of applications such as preventing the spread of fire in occupied structures, providing security to protect windows and doorways, and to cover large openings in walls where the use of large paneled doors is cumbersome or impractical such as openings for the passage of vehicles.
A curtain door system generally includes a curtain door having a series of interlocking slats of metal or plastic that spans an opening. The curtain door mounts above an opening or window on mounting hardware, and during operation is guided into position by guide rails at the periphery of the opening. The mounting hardware may include a pipe or drum that rotates between two head plates, and from which the curtain door is suspended. The interlocking feature of the slats allows the curtain door to be rolled about the pipe or drum when opening or closing the curtain door. Manufacturers typically ship curtain doors with the curtain door wound about the pipe or drum, or connected to the mounting hardware and drive mechanism. However, installation of the curtain door may be performed after installation of the guide rails, pipe, mounting hardware, and drive mechanism.
Rolled curtain doors are often heavy and awkward to install. Conventional installation methods require suspending the rolled curtain door below the pipe using slings or ropes. Workers pull on the ropes to lift the door up to the pipe for attachment. Workers next ascend ladders and manually adjust the orientation of the rolled door to align the top slat with the pipe, and connect the two. The curtain door is then rolled off of the ropes and onto the pipe. As a result, the conventional tools and process used to install curtain doors is fraught with challenges, especially when installing doors that weigh hundreds of pounds, or used to cover large openings having great height or width. Moreover, the conventional installation process can lead to injury of the workers installing the door because of a need to use body strength and ladders to complete installation. Therefore, there is a need for a curtain door installation system that permits a worker to safely and accurately install a curtain door regardless of the height of the opening the door will cover, and the size and weight of the door.
Therefore, those who install curtain door systems desire an installation tool that provides an efficient and safe method for installing these systems. The disclosed subject matter provides these features and advantages.
SUMMARY OF THE INVENTION
In accordance with the invention, a rolled curtain door may be supported by an adjustable cradle having rollers, that are configured to support the curtain door and permit rolling of the door thereon to aid in mounting the door to mounting hardware. The cradle has extensions with rollers that may be extended, thereby allowing the cradle to support rolled curtain doors of varying length. The cradle may be mounted on the tines of a fork on a lifting device, such as a forklift or lifting assembly, to raise raising the curtain door up to a mounting position on a wall above a door opening. Optionally, the rollers may be powered by a motor to rotate the door and assist in mounting it to door hardware.
If desired, particular embodiments may optionally include a lift assembly attached to the cradle. The lift assembly includes a tower extendable by a piston and cylinder unit. The tower has a fork with tines projecting therefrom. The tower is attached to a base having casters for manually rolling the cradle and lift assembly around a worksite. Stabilizers on the base may be used to support and level the assembly when in use. A winch motor with a cable is attached to the tower and may be used to assist in loading a rolled curtain door onto the cradle. Optionally, a hoist attached to the tower may be used to load a rolled curtain door onto the cradle.
BRIEF DESCRIPTION OF THE DRAWINGS
The drawings constitute a part of this specification and include exemplary embodiments of the disclosed subject matter illustrating various objects and features thereof, wherein like references are generally numbered alike in the several views.
FIG. 1 is a rear perspective view of a first alternative embodiment curtain door installation system embodying principles of the disclosed subject matter where a cradle supporting a rolled curtain door is attached to, and elevated by, a lifting device.
FIG. 2 is a rear perspective view of the curtain door installation system embodying principles of the disclosed subject matter showing the cradle with extensions assemblies extended from a central assembly.
FIG. 3 is a front elevational view of the cradle attached to a lifting device.
FIG. 4 is a second alternative embodiment curtain door installation system including a cradle attached to a lift with an integrated hoist.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
As required, detailed aspects of the disclosed subject matter are disclosed herein; however, it is to be understood that the disclosed aspects are merely exemplary of the invention, which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art how to variously employ the present invention in virtually any appropriately detailed structure.
Certain terminology will be used in the following description for convenience in reference only and will not be limiting. Said terminology will include the words specifically mentioned, derivatives thereof and words of similar meaning.
Referring to the drawings in more detail, the reference numeral 101 generally designates a curtain door installation system embodying the principles of the disclosed subject matter. Referring to FIG. 2 , the system 101 generally includes a cradle 102 having a central assembly 104 , and first and second extension assemblies 152 and 154 . By way of example, and not to be construed as limiting, the system 101 is shown in FIG. 1 attached to a lift assembly 202 , and elevated, for installing the rolled curtain door 310 above an opening 302 in a wall 304 . A rolled door system generally includes a curtain door 310 attached to a pipe or drum located between two head plates 306 , a drive mechanism for raising and lowering the curtain door 310 , and guide rails for keeping the curtain door 310 aligned with the opening during operation.
Referring to FIG. 2 , cradle 102 generally comprises a central assembly 104 , and first and second extension assemblies 152 and 154 . Central assembly 104 includes a cross member 106 having a pair of fork sleeves 108 secured to the underside, and two roller assemblies 114 secured to the top. Cross member 106 may comprise a hollow steel tube with opposite open ends, and having a rectangular cross section for slidably receiving a leg 156 of first or second extension assemblies 152 and 154 . Cross member 106 is the part that supports the roller assemblies 114 , and for mounting first and second extension assemblies 152 and 154 . Fork sleeves 108 comprise a steel tube having a rectangular cross section, and dimensioned to slidably receive the tines of a fork from a lifting device including, but not limited to, lift assembly 202 , a forklift or a lift truck (not shown). Each fork sleeve 108 has an aperture 110 for receiving a locking member such as a locking pin or a set bolt 112 to secure cradle 102 to the fork of the lifting device. Alternatively, fork sleeves 108 may be welded to the fork.
Each roller assembly 114 includes an arm 116 mounting two rollers that are opposite each other and allow free rotation of the roller thereon. The roller may include, but is not limited to, a metal, plastic, or composite drum, wheel, or tube, preferably a wheel 120 having a rubber contact surface. Wheels 120 are mounted on arm 116 by a vertical support 115 , wherein the rotational axis of wheel 120 is perpendicular to arm 116 , and wheel 120 is spaced a sufficient distance apart as to cradle a rolled curtain door 310 . Although a wheel 120 is shown and described, any suitable roller or rollers may be used with cradle 102 that permits free rotation of the rolled curtain door 310 thereon. Roller assemblies 114 are mounted with arm 116 perpendicular to cross member 106 , thereby supporting rolled curtain door 310 parallel to cross member 106 . The fork sleeves 108 , cross member 106 , vertical support 115 , and roller assemblies 114 are secured by welding, or alternatively, by fasteners such as a nut and bolt combination.
Cradle 102 may suitably function with or without first and second extension assemblies 152 and 154 . Extension assemblies 152 and 154 may be connected to central assembly 104 when supporting an especially wide or heavy curtain doors 310 . First extension assembly 152 includes leg 156 mounting roller assembly 114 at one end. Leg 156 comprises a solid or hollow steel tube having a rectangular cross section adapted for insertion into cross member 106 . Roller assembly 114 may be secured to leg 156 by a pair of U-bolts 158 , nuts 160 , and a plate 162 , or alternatively by welding.
Second extension assembly 156 is generally identical to first extension assembly 152 and therefore will not be described. Leg 146 end opposite roller assembly 114 is inserted into the open end of cross member 106 with roller assembly 114 facing up, and are slid in and out as needed to position first and second roller assemblies 114 under the rolled curtain door 310 .
Cradle 102 may optionally be powered by a motor 276 that can rotate wheels 120 thereby rotating the rolled curtain door 310 thereon when mounting the curtain door 310 above an opening. Roller assemblies on cross member 106 may be connected by a shaft 174 having a driven sprocket 172 . Driven sprocket 172 is connected to a drive sprocket 176 on motor 276 by a chain 178 . Motor 276 is mounted on either lift assembly 202 or cross member 106 , preferably lift assembly 202 . Motor 276 may be an electrical motor powered by a suitable electrical power supply, or a hydraulic motor powered by an complimentary power source.
In use, cradle 102 is mated to a lifting device having a pair of forks projecting therefrom. The forks are inserted into fork sleeves 108 , and cradle 102 is secured to the forks by tightening set bolts 112 in apertures 110 . First and second extension assemblies 152 and 154 are adjusted or removed, as needed, to properly support a rolled curtain door 310 . A curtain door 310 is then loaded onto cradle 102 , and cradle 102 is then raised up to the proper height above an opening where the rolled curtain door 310 is attached to the installed door mounting hardware such as a pipe or drum. After the rolled curtain door 310 is attached to the mounting hardware, roller assemblies 114 allow free rotation of the curtain door 310 off of the cradle 102 as the curtain door 310 is rolled onto the pipe or drum, or motor 276 may be engaged to rotate wheels 120 to assist in transferring the rolled curtain door 310 to the door mounting hardware.
Occasionally a rolled curtain door 310 may already be attached to mounting hardware and a drive mechanism. Therefore, although a rolled curtain door 310 is described, cradle 102 may be used to install a rolled curtain door above a doorway when the rolled curtain door already has its mounting hardware installed using the same process describe above.
Supporting the rolled curtain door 310 with cradle 102 , and using roller assemblies 114 to transfer the curtain door 310 to the mounting hardware avoids the perils previously encountered when installing curtain doors. Namely, workers can avoid use of straps, step ladders, and body strength currently necessary to suspend and raise heavy curtain door below its mounting hardware. This provides workers with a tool to safely and accurately install a curtain door regardless of the height or location of the mounting hardware, and the size or weight of the door.
A curtain door installation system comprising a first alternative embodiment curtain door installation system 201 is shown in FIGS. 1 and 2 , and includes a cradle 102 attached to lift assembly 202 . Lift assembly generally comprises a tower 252 connected to a base 204 . The generally rectangular base 204 includes a frame 206 constructed of tubular members having a rectangular cross section. Frame 206 comprises a rectangle having front and rear members 208 and 210 , and interconnecting side members 212 and 214 . The ends of front and rear members 208 and 210 are joined to their respective side members 212 and 214 in a conventional manner such as by welding. Base 204 is supported by casters 216 secured to frame 206 allowing lift assembly 202 to be rolled around a worksite by a worker.
A deck 218 is secured to frame 206 and provides a mounting surface for two deck ribs 220 . Each deck rib 220 is located on top of deck 218 adjacent to a side member 212 and 214 . Ribs 220 comprise a solid or hollow steel tube having a rectangular cross section, and traverse deck 218 from front to back adding rigidity to base 204 . The front and rear of each rib 220 provides a mounting surface for a stabilizer 222 used to bias against the surface supporting lift assembly 202 , thereby stabilizing and holding lift assembly 202 when in use. Stabilizer 222 may be a conventional manually-operated stabilizer, or a mechanical stabilizer operated using electric or hydraulic power.
Tower 252 generally comprises an extendable mast 254 that raises and lowers a fork 266 . Mast 254 is centered at the rear of base 204 and secured thereto by welding. Mast 254 is further secured to base 204 by a heel 256 that is secured to both deck 218 and mast 254 by welding, completing formation of a rigid box-like structure that adds further stability to the connection between base 204 and mast 254 . Mast 254 is further stabilized by angular trusses 260 secured to mast 254 at one end, and base 204 at the other end by welding. A handle 262 on the rear of each truss 260 permits a worker to manually maneuver lift assembly 202 .
Mast 254 comprises interlocking rails supporting a carriage 264 and a forward-facing fork 266 . Mast 254 functions in a similar manner as those found on a forklift truck for raising and lowering carriage 264 and fork 266 . Mast 254 is raised and lowered by a piston and cylinder unit (p-c unit) 268 connected at one end to base 204 and at another end to mast 254 by a chain. P-c unit 268 communicates with a reservoir 270 via a valve 272 and hose 274 . P-c unit 268 may function using a pneumatic system or a hydraulic system, preferably a pneumatic system. Actuation of valve 272 to a first position extends p-c unit 268 and raises fork 266 . Actuation of valve 272 to a second position ceases movement of p-c unit 268 . Actuation of valve 272 to a third position withdraws p-c unit 268 and lowers fork 266 .
A winch motor 226 winds-up and lets out a cable 228 having a hook 230 for connecting to a rolled curtain door 310 . Cable 228 passes through a guide 232 keeping cable 228 aligned with winch motor 226 and a wheel 234 disposed at the top of the mast 254 . Wheel 234 allows for cable 228 to roll on when lifting a rolled curtain door 310 onto cradle 102 .
In use, curtain door installation system 201 provides for installation of a rolled curtain door 310 without the need of a forklift truck. Cradle 102 is attached to fork 266 of the lift assembly 202 in the same manner as described above. First and second extension assemblies 152 and 154 are adjusted or removed as needed depending on the size or weight of the rolled curtain door 310 . After loading a rolled curtain door 310 onto cradle 102 using cable 228 and winch 226 , lift assembly 202 may be freely rolled across a surface. Using handles 262 , a worker can manually position lift assembly 202 and curtain door 310 below an opening to be covered. After engaging stabilizers 222 to immobilize and level lift assembly 202 , a worker actuates valve 272 to the first position to raise fork 266 and cradle 102 . When cradle 102 has reached the proper height to offload the rolled curtain door 310 to the mounting hardware, valve 272 is moved to the second position stopping movement of cradle 102 . After the curtain door 310 is offloaded, valve 272 is moved to the third position permitting cradle 102 to be lowered to the ground.
A curtain door installation system comprising a second alternative embodiment curtain door installation system 401 is shown in FIG. 4 , and includes cradle 102 and lift assembly 202 as described above, and further including hoist 402 . Hoist 402 is attached to the top of tower 252 for assisting in loading a rolled curtain door 310 onto cradle 102 . Hoist 402 generally includes a boom 404 that pivots atop tower 252 , and a p-c unit 418 for raising and lowering boom 404 . Boom 404 extends forward from the rear of lift assembly 202 across the top of tower 252 , terminating in front of lift assembly 202 . Boom 404 may comprise a hollow steel tube having a rectangular cross section. Boom 404 pivots about a bracket 408 extending from the top of tower 252 . P-c unit 418 attaches at one end to the rear of boom 404 , and at another end to tower 252 . P-c unit 418 may function in a similar manner, and use like components, as p-c unit 268 described above. A hook 406 at the forward end of boom 404 allows for connection of a chain 410 . Straps 414 may be wrapped around the rolled curtain door 310 and connected to the free end of chain 410 by a cable 412 . Optionally, electrically-powered lights 416 may be attached to tower 252 providing illumination of cradle 102 and workspace.
In use, the rolled curtain door 310 is connected to the hoist 402 as described above. Actuation of p-c unit lifts the rolled curtain door 310 off of the ground or a vehicle. Workers may then guide the rolled curtain door 310 over cradle 102 and lower boom 404 thereby placing the door 310 between wheels 120 of the cradle 102 . Rolled curtain door 310 is then disconnected from hoist 402 , and raised into position on cradle 102 for installation.
It will be appreciated that the components of cradle 102 and installation systems 101 , 201 , and 401 may be used for various other applications. Moreover, cradle 102 and installation systems 101 , 201 , and 401 may be fabricated in various sizes and from a wide range of suitable materials, using various manufacturing and fabrication techniques.
It is to be understood that while certain aspects of the disclosed subject matter have been shown and described, the disclosed subject matter is not limited thereto and encompasses various other embodiments and aspects. | A cradle for supporting and installing a rolled curtain door comprises rollers configured to support, and permit rolling, of a rolled curtain door thereon. Extensions with rollers permit the cradle to support rolled curtain doors of varying length. A motor may be connected to the rollers to assist in rotating the door. The cradle may be mounted on the tines of a fork on a lifting device. A lift assembly having a tower and base may be attached to the cradle for manually positioning, and mechanically elevating the cradle and door when installing the door. The tower is extended by a piston-and-cylinder unit. A winch motor and cable, or a boom hoist attached to the tower may be used to load a door onto the cradle. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority from U.S. provisional application Ser. No. 60/410,869 filed on Sep. 12, 2002, incorporated herein by reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable
INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC
Not Applicable
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention pertains generally to above ground fuel tanks for generators, and more particularly to a lightweight, low profile base tank with fire resistive, impact resistive and leak protection elements.
2. Description of Related Art
Many auxiliary generators that provide remote or backup power are mounted on a base tank as an integrated system. The base tank is required to provide sufficient fuel to the generator system to run for extended periods of time without refueling. Space for installation and access for auxiliary generators is often constrained by site features and facility design, limiting the equipment that may be used for positioning. For a given space, the dimensions and profile of the tank, along with the necessary mounting system for the generator, define the volume of fuel that may be accommodated in a base tank.
In most applications, aboveground tanks must have secondary containment to prevent fuel leaks to the environment and employ a double wall tank design. Underwriters Laboratory Inc. (UL) 142 standard (incorporated herein by reference) for steel aboveground tanks for flammable and combustible liquids is a safety standard that has been followed to construct commercially available double wall tanks for more than 14 years. A more recent UL 2085 standard for protected aboveground tanks (incorporated herein by reference) specifies limits to the heat transferred to the primary, or inner fuel tank, when exposed to a two-hour hydrocarbon pool fire. This standard further specifies a protection requirement from physical damage including projectile damage.
Commercially available base tanks constructed to the UL 2085 standard typically use a double wall metal tank with concrete, solidified foam or other solid insulating material in an interstitial space of about six inches to resist the heat of a two hour fire and provide damage and projectile protection. The fire resistant insulation is typically installed before the tank is transported to the site. Increased tank weight increases cost and complexity of installation, however. The relatively large interstitial space required for solid insulating material significantly increases the footprint of the base tank and decreases fuel volume for a given installation space. Furthermore, once installed, solid insulating material cannot be easily removed from the interstitial space for inspection or repair.
By way of example, U.S. Pat. Nos. 6,422,413 and 5,271,493 to Hall et al., incorporated herein by reference, teach using about six inches of poured concrete as an insulator. The concrete works well as a fire shield, however, the concrete also makes the tank extremely heavy and cumbersome to transport and install. Further, once the concrete has hardened, it cannot be readily removed for tank inspection or repair.
U.S. Pat. Nos. 6,026,975, 6,257,437 and 6,349,873 to Slater, incorporated herein by reference, disclose Perlite, Vermiculite, fire retardant polymeric foam, ceramic or cementitious materials such as regular concrete, sand or a cementitious material containing a aggregate as an insulator material in the interstitial space. Slater describes a solid insulation, preferably concrete, in an interstitial space, preferably 6 inches to provide the required fire resistance and impact resistance for the UL 2085 standard. Slater does not teach a tank embodiment with an interstitial space of less than 6 inches that meets the UL 2085 standard nor the use of a non-solid fire resistant insulation in the interstitial space.
Other methods have been employed to provide fire resistance to above-ground fuel tanks. For example, U.S. Pat. Nos. 5,285,920; 5,012,949; 5,038,456 and 4,989,750 to McGarvey et al., incorporated herein by reference, describe above-ground fire resistant tanks that have a sprayed-on exterior fire resistant intumescent material such as Chartek. McGarvey further teaches a double wall tank embodiment with a solid insulation material such as Vermiculite, foamed concrete, Fendolite, Styrofoam or pumice in the double wall space. McGarvey does not, however, teach a combination of exterior fire resistant material, interstitial insulation and support structure necessary to function as a generator base tank. Furthermore, McGarvey does not teach a non-solid insulation material for the interstitial space.
Although several above-referenced patents suggest materials other than A-36 mild steel for tank walls, such as plastic, fiberglass, or corrosion resistant steel, they do not suggest any particular type of steel that would provide the combined advantage of improved heat conduction, impact resistance, and as corrosion resistance to a water base fire resistant solution in the interstitial space. In fact, the corrosion resistant steels described do not exhibit those properties.
Furthermore, in order to support a generator on the top of a base tank, there must be a support structure extending from the equipment pad, to the mounts of the generator on the tank. For example, U.S. Pat. Nos. 6,026,975, 6,257,437 and 6,349,873 to Slater, incorporated herein by reference, disclose stiffening members for the top and bottom walls of the inner tank, top and side walls of the outer tank, and support beams along the top outer tank wall. These stiffening members provide support for the generator, however this external support configuration adds significant weight and size to the tank system and can interfere with generator maintenance access.
Therefore, there is a need for a lightweight low-profile base tank designed to meet the UL 2085 standard and support commercially available generators. Further, the capability to install a fire resistant material in the interstitial space after tank installation and inspect and repair the tank without dismantling is highly beneficial to overcome shortcomings of bulkier and heavier generator base tanks.
BRIEF SUMMARY OF THE INVENTION
The present invention satisfied the foregoing needs and overcomes deficiencies in previously developed tanks by providing, according to one aspect of the invention, a lightweight base tank for a generator system comprising an outer tank of type 316 stainless steel and an inner tank of type 316 stainless steel with structural baffles in the inner tank. In one embodiment, the outer tank and inner tank are structurally coupled to form a relative small interstitial space. An intumescent fire resistant coating impregnated with a thermal resistant fiberglass mesh is placed on the outside of the outer tank. After the tank is installed, the interstitial space between the inner tank and outer tank is filled with a fire resistant solution.
The inventive combination of a type 316 double wall steel tank with an outer intumescent fire resistant coating coupled with a fire resistant solution in the interstitial space exhibits sufficient fire resistance to meet the UL 2085 standard. The physical properties of the type 316 stainless steel combined with the fire resistant solution in the interstitial space also exhibit sufficient resistance to physical and projectile damage to meet the UL 2085 standard.
In one embodiment, generator mounts on the top of the outer tank are supported in part by structural baffles in the inner tank and interstitial spacers between the inner tank and outer tank. No external columns, beams or stiffeners are necessary to support a generator.
The fire resistant solution can be removed for inspection or repair of the tank at the site. A leak detection system with a level sensor is located in the interstitial space and can detect a leak in the outer tank or in the inner tank. A water detection system may also be located in the inner tank to detect leaks. An antifreeze solution is optionally added to the fire resistant solution to protect the solution from freezing in cold climates.
One aspect of the invention is a light weight base tank for a generator using type 316 stainless steel for the walls of the inner tank and the walls of the outer tank. In one mode of this aspect, the thickness of the outer tank walls is about one-quarter inch. In another mode of this aspect, the thickness of the inner tank walls is about three-sixteenths of an inch.
Another aspect is a base tank having type 316 stainless steel for tank walls for beneficial heat conductance, projectile resistance and corrosion resistance.
A further aspect is a base tank with baffles configured in an inner tank for heat conduction and internal support. In one mode of this aspect, the baffles are made of type 316 stainless steel. In another mode, the baffles couple opposite side walls of the inner tank and couple the top wall and bottom wall of the inner tank.
Another aspect is a base tank with a coating of intumescent paint on the outer tank. In one mode of this aspect, a thermal resistant fiberglass mesh is embedded in the coating of intumescent paint. In another mode the intumescent paint is Thermolag 3000™.
A further aspect is a base tank with an interstitial space between the inner tank and the outer tank of about two inches or less for side and bottom walls and about four inches or less for top walls. In beneficial mode of this aspect, the interstitial space between the side walls and bottom walls of the inner tank and the outer tank is about one inch.
A still further aspect is a lightweight low profile base tank that meets the UL 2085 standard.
Another aspect is a base tank with a fire resistant solution installed in the interstitial space between the inner tank and the outer tank. In one mode of this aspect, the fire resistant solution is installed after the base tank is in place. In another mode, the fire resistant solution can be removed to inspect or repair the base tank while the base tank remains in place. In a further mode, the base tank can be put back in service after a fire by replacing the fire resistant solution.
A further aspect is a fire resistant solution consisting of at least two percent fire blocking gel and at least eighty-eight percent water. In one mode, the fire resistant solution is BARRICADE™. In another mode, the fire resistant solution can be modified to prevent freezing during cold temperatures. In a further mode, the fire resistant solution contains up to ten percent propylene glycol to prevent freezing.
Another aspect is a lightweight low profile base tank with an internal support structure that includes baffles in the inner tank. In one mode of this aspect, a plurality of generator mounts are coupled directly to the top of the outer tank with no external support beams. In another mode, tubular generator supports couple the top of the inner tank to the top of the outer tank and align with the baffles in the inner tank and the generator mounts on top of the outer tank
A further aspect is a base tank with a leak detection system with a level sensor in the interstitial space to detect loss of a fire resistant solution.
A still further aspect is a base tank with a water detection system in the inner tank to detect water, or a solution containing water, leaking into the inner tank from the interstitial space.
Further aspects of the invention will be brought out in the following portions of the specification, wherein the detailed description is for the purpose of fully disclosing preferred embodiments of the invention without placing limitations thereon.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
The invention will be more fully understood by reference to the following drawings which are for illustrative purposes only:
FIG. 1 is a perspective view of the exterior of a base tank for a generator according to the present invention.
FIG. 2 is a partial cross-section view of the base tank shown in FIG. 1 taken through lines 2 - 2 .
FIG. 3 is partial cross-section view of the base tank shown in FIG. 1 taken through lines 3 - 3 .
FIG. 4 is a side view of an alternative embodiment of the generator mount configuration shown in FIG. 1 , wherein two baffles are employed.
FIG. 5 is side view of a base tank according to the present invention shown with a generator, related components, and enclosure mounted on top shown in phantom.
DETAILED DESCRIPTION OF THE INVENTION
Referring more specifically to the drawings, for illustrative purposes the present invention is embodied in the apparatus generally shown in FIG. 1 through FIG. 5 . It will be appreciated that the apparatus may vary as to configuration and as to details of the parts, and that the method may vary as to the specific steps and sequence, without departing from the basic concepts as disclosed herein. All joints are typically made with welds unless otherwise specified.
FIG. 1 is a perspective view of the exterior of a fire resistant base tank assembly 10 before a fire resistant coating (shown in FIG. 2 and FIG. 3 ) is applied. Details of tank components such as ports for instrumentation, fuel supply, fuel return and venting, brackets for lifting and securing, and tank cut outs for electrical connections, as are known in the art, are omitted for clarity. Base tank assembly 10 comprises an outer tank 20 and an inner tank 50 which are positioned and configured as will be more fully described below.
Outer tank 20 has a top wall 22 , two side walls 24 , two end walls 26 , and a bottom wall 28 . Outer tank 20 is preferably made from type 316 stainless steel or equivalent and, in a particular embodiment, the walls are one-quarter inch thick. A pair of base members 30 , coupled to side walls 24 , are provided to support tank 10 when it is placed on an equipment pad (not shown). Base members 30 preferably have reinforcement tabs 32 coupled to side walls 24 . In one embodiment, base members 30 and reinforcement tabs 32 are made from one-half inch stainless steel. A center support 36 , extending between end walls 26 , is coupled to the outside of bottom wall 28 and centered between base members 30 to provide further support to bottom wall 28 on the equipment pad. In one particular embodiment, center support 36 is one-half inch thick stainless steel. A plurality of generator mounts 38 are coupled to top wall 22 and are shown in further detail in FIG. 2 through FIG. 4 .
An access port 40 , level detector 42 , fuel port 44 , and water detector 46 are also provided as will be described further with reference to FIG. 2 and FIG. 3 . FIG. 2 is a partial side sectional view of the base tank assembly 10 in FIG. 1 , and FIG. 3 is a partial end sectional view of the base tank assembly 10 in FIG. 1 . Access port 40 , level detector 42 , fuel port 44 and water detector 46 are repositioned in these views for clarity.
Inner tank 50 has a top wall 52 , two side walls 54 , two end walls 56 and a bottom wall 58 . Inner tank 50 is preferably made of type 316 stainless steel or equivalent and, in a particular embodiment, is three-sixteenths inches thick. Inner tank 50 is fluidly connected to one or more fuel ports 44 which can be used for filling, venting, fuel supply, fuel return or measurement. Water detector 46 has a sensor 48 positioned in inner tank 50 adjacent bottom wall 58 to detect the presence of water.
Inner tank 50 is positioned within outer tank 20 to form an interstitial space 60 which is fluidly connected to access port 40 . Interstitial space 60 has a top space 62 defined by top walls 22 and 52 , two side spaces 64 defined by side walls 24 and 54 , two end spaces 66 defined by end walls 26 and 56 , and a bottom space 68 defined by bottom walls 28 and 58 . In one mode, top space 62 is at least about four inches between top wall 22 and top wall 52 , side spaces 64 are about one to two inches between side walls 24 and 54 , end spaces 66 are one to two inches between end walls 26 and 56 , and bottom space 68 is about one to two inches between bottom walls 28 and 58 . In the preferred embodiment, side spaces 64 , end spaces 66 and bottom space 68 are about one inch between walls.
One or more access ports 40 are fluidly connected to interstitial space 60 and can be used for filling, venting, measurement or removal of a fluid. Level detector 42 is fluidly connected to interstitial space 60 and detects a change in level of a fluid in interstitial space 60 .
The bottom wall 58 of inner tank 50 is supported by and coupled to bottom wall 28 of outer tank 20 by spacer tube 70 . Spacer tube 70 is preferably made of type 316 stainless steel or equivalent and extends the width of end walls 56 of inner tank 50 . In one particular embodiment, spacer tube 70 is one inch by one inch box tubing. Other spacers with cross sections as channels, angles or hats, as are known in the art, may also be used.
The top wall 52 of inner tank 50 is supported by and coupled to bottom wall 58 of inner tank 50 by tank baffles 72 having one or more holes 86 therethrough for fuel flow. Tank baffles 72 also couple the side walls 54 of inner tank 50 . Tank baffles 72 are spaced as necessary for support, but preferably not greater than approximately twenty-four inches apart and are structurally aligned with spacer tubes 70 . Tank baffles 72 are preferably made of type 316 stainless steel or equivalent.
The top wall 22 of outer tank 20 is supported in part by, and coupled to, top wall 52 of inner tank 50 by a plurality of tubular generator supports 74 . Tubular generator supports 74 are positioned to support generator mounts 38 and are structurally aligned with one or more baffles 72 . Tubular generator supports 74 may also be used to support top wall 22 in locations not associated with generator mounts 38 . In one beneficial embodiment, tubular generator supports 74 are an eight inch by eight inch box tubing of one-quarter inch thick plate stainless steel about four inches long.
A generator system (as shown in FIG. 5 ) can be supported on tank assembly 10 without external columns, stiffening members or beams by the beneficial configuration and coupling of base elements 30 , center support 36 , bottom wall 28 , spacer tubes 70 , bottom wall 58 , tank baffles 72 , top wall 52 tubular generator supports 74 , top wall 22 and generator mounts 38 .
Top wall 22 of outer tank 20 is also supported in part by an interstitial baffle 76 that couples top wall 22 of outer tank 20 to top wall 52 of inner tank 50 and is further aligned with a tank baffle 72 . Interstitial baffle 76 typically couples to side walls 24 and is adapted with openings (not shown) for the flow of fluid. In a beneficial embodiment, interstitial baffle 76 is made of one-quarter inch stainless steel or the like. In one beneficial embodiment, there is at least one interstitial baffle 76 for each pair of generator mounts 38 .
The outside surface of top wall 22 , side walls 24 , and end walls 26 of outer tank 20 are covered by a layer of fire resistant fiberglass mesh 80 . The fiberglass mesh 80 is in turn covered by a coat of intumenscent paint 82 . In one particular method of installation, a first coat of intumescent paint 82 is applied to the walls of tank 20 . The fiberglass mesh 80 is applied while the first coat of intumescent paint 82 is still wet. A second coat of intumenscent paint 82 is the applied over fiberglass mesh 80 , effectively embedding the fiberglass mesh 80 within a thick coating of intumescent paint 82 . In a preferred embodiment, the intumescent paint 82 is Thermolag 3000™. In a preferred embodiment, the thickness of the fiberglass mesh 80 with the intumescent paint 82 on the outside walls of tank 20 is about one-eight inch.
Interstitial space 60 , defined by the opposing walls of outer tank 20 and inner tank 50 , is filled with a fire resistant solution 84 through an access port 40 , preferably after site installation of tank assembly 10 . Fire resistant solution 84 comprises, in part, a compound that will significantly reduce the movement of a fluid, such as water, by convection when exposed to heat. A fire block gel, such as BARRICADE™, exhibits this property. Fire resistant solution 84 preferably comprises at least two percent fire block gel mixed with at least about eighty-eight percent water. Up to about ten percent propylene glycol may be added to fire resistant solution 84 to provide freeze protection.
The specific use of type 316 stainless steel for outer tank 20 , coated with fire resistant fiberglass mesh 80 and intumescent paint 82 , combined with fire resistant solution 84 in interstitial space 60 and the use of type 316 stainless steel for inner tank 50 and tank baffles 72 , results in base tank 10 having a two-hour fire rating and resisting physical damage sufficient to meet the UL 2085 standard.
Referring now to FIG. 4 , an alternative embodiment of a support configuration for a generator mount 38 is shown. In this embodiment, a pair of baffles 72 are coupled to top wall 52 and aligned to provide support to tubular generator support 74 coupled to top wall 52 . In this way, additional structural support for generator mount 38 is provided through top wall 22 .
FIG. 5 illustrates a generator system 100 mounted on a base tank assembly 10 with generator mounts 38 and without external brackets, beams or stiffeners. Connections, controls, panels and relief valves, known in the art, have been omitted for clarity. Alignment of baffles 72 and alignment of tubular generator supports 74 , are illustrated for the particular mounting configuration shown. Generator system 100 includes a motor 102 , a generator 104 , a radiator 106 , and an exhaust system 108 , shown partially in phantom. In this embodiment, an optional enclosure 110 is also supported by base tank assembly 10 without external brackets, beams or stiffeners. Enclosure doors and panels have been omitted for clarity. Enclosure 110 includes an exhaust fan 112 , an exhaust vent 114 and an air intake 116 . Enclosure 110 is preferably lined with a soundproofing material 118 , shown in phantom, for sound attenuation.
As can be seen, therefore, the present invention comprises a base tank for storing flammable and combustible liquids and supporting a generator. In the preferred embodiment, the base tank has an inner tank and outer tank. A plurality of baffles couple opposing side walls of the inner tank and further couple the bottom wall of the inner tank to the top wall of the inner tank. The inner tank is positioned in relation to the outer tank such that an interstitial space is defined between said walls of said outer tank and said walls of said inner tank, which is filled with a fire resistant solution. Preferably the fire resistant solution comprises at least about 2 percent fire blocking gel, such as BARRACADE™, and at least about 88 percent water. More preferably, the fire resistant solution comprises up to about 10 percent propylene glycol. Also, the walls of the inner and outer tanks are preferably fabricated from type 316 stainless steel having a thickness at least about 3/16 inch.
The walls of the outer tank are preferably coated or covered with a fire resistant material. Preferably, the fire resistant material comprises fire resistant fiberglass mesh coated with an intumescent paint, and more preferably, the intumescent paint comprises a ⅛ th inch coating of Thermolag 3000™.
In a further preferred embodiment, the interstitial space adjoining said sidewalls of said inner tank and adjoining said bottom wall of said inner tank is about 2 inches or less, and the interstitial space adjoining said top wall of said inner tank is about 4 inches or less. More preferably, the interstitial space adjoining said sidewalls of said inner tank and adjoining said bottom wall of said inner tank is about 1 inch.
Optionally, the base tank can include means for supporting a generator. Preferably, said means comprises (i) a plurality of base support members adapted to couple the bottom wall of the outer tank to an equipment pad and further adapted to support the weight of said base tank and a generator, (ii) a plurality of interstitial spacers configured to support the bottom wall of the inner tank on the bottom wall of the outer tank where the interstitial spacers are structurally coupled to the base support members and further adapted to support the weight of said inner tank and a generator, (iii) where the baffles in the inner tank are structurally coupled to the interstitial spacers and where the baffles are further adapted to support the weight of a generator, (iv) a plurality of tubular generator supports adapted to couple the top wall of the inner tank to the top wall of the outer tank in the interstitial space, (v) wherein the tubular generator supports are structurally aligned with the baffles and further adapted to support the weight of a generator, and (vi) a plurality of generator mounts coupled to the top wall of the outer tank, where the generator mounts are structurally coupled to the tubular generator supports and the generator mounts are further adapted to support the weight of a generator. Preferably, the baffles are spaced apart at a spacing of about 24 inches or less.
As a further option, a level detector configured to detect change of level of the fire resistant solution in the interstitial space can be included. Another optional aspect of the invention is a water detector configured to detect the presence of water in the inner tank.
Although the description above contains many details, these should not be construed as limiting the scope of the invention but as merely providing illustrations of some of the presently preferred embodiments of this invention. Therefore, it will be appreciated that the scope of the present invention fully encompasses other embodiments which may become obvious to those skilled in the art, and that the scope of the present invention is accordingly to be limited by nothing other than the appended claims, in which reference to an element in the singular is not intended to mean “one and only one” unless explicitly so stated, but rather “one or more.” All structural, chemical, and functional equivalents to the elements of the above-described preferred embodiment that are known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the present claims. Moreover, it is not necessary for a device or method to address each and every problem sought to be solved by the present invention, for it to be encompassed by the present claims. Furthermore, no element, component, or method step in the present disclosure is intended to be dedicated to the public regardless of whether the element, component, or method step is explicitly recited in the claims. No claim element herein is to be construed under the provisions of 35 U.S.C. 112, sixth paragraph, unless the element is expressly recited using the phrase “means for.” | An above-ground, double-walled, tank for holding combustible material and supporting a generator has an outer tank and an inner tank with structural baffles, all made from type 316 stainless steel. An interstitial space formed by the outer tank and inner tank is filled with a fire resistant solution consisting of a fire block gel and water. An internal support system, including structural baffles in the inner tank, provide a structure to support a generator and other equipment on the top of the tank without the use of tank wall stiffeners or external beams. A level detector in the interstitial space detects changes in the level of the fire resistant solution. A water detector in the inner tank detects the presence of water. The fire resistant solution may be removed from the interstitial space for tank inspection and repair. | 1 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an improved irregular surface which may be utilized in conjunction with a bone implant to facilitate the growth of bone tissue within the surface. The invention also relates to a method of production of this surface. The irregular surface is created on a substrate material to particularly adapt that surface for joining to a second material. More specifically, the invention relates to the sequential etching of a bone implant surface to produce an irregular random pattern of protrusions and depressions through the use of chemical and electrochemical milling techniques and the subsequent blasting of the surface to produce micro features on the surface.
[0003] 2. Description of the Prior Art
[0004] In the field of bone implantation, or the use of man-made objects to replace portions of bone within the human body, there are two primary methods of affixing the implant device to the existing bone. The first of these methods involves the use of a cement or adhesive material which is applied to the surfaces of the implant and the bone. The cement is adapted to harden in a rapid fashion and rigidly affix the two portions in an immobile manner. The use of cement permits the application of loads to the joinder of the bone and the implant within a relatively short time following implantation. This is generally desirable in terms of the well-being of the patient, in that a quick physical recovery improves the overall recovery of the patient.
[0005] One of the significant shortcomings of a cement adhesion of the two elements is that over time, the cement tends to deteriorate. This deterioration may permit relative movement between the implant and the bone surface and if untreated, could allow the two joined elements to separate. In either event, the result is painful and dangerous to the patient.
[0006] A second method of affixation of the implant to the bone has also been utilized as an alternative to the cement technique. In this embodiment, the implant is provided with an irregular surface into which the bone may grow, creating a natural joinder between the bone and the implant. One of the shortcomings of this implantation technique, however, is the longer recovery time necessary to permit ingrowth of the bone into the surface of the implant. An additional problem which has occurred with relation to the ingrowth embodiment relates to the preparation of the surface of the implant. An implant having a smooth surface is inappropriate for use in this type of operation as it provides no gripping surface for the bone. An irregular surface, therefore, is preferred and in fact necessary for this application. Several methods have been proposed in the prior art for the preparation of the surface, such that a stable gripping surface will be provided into which the bone may grow.
[0007] Frye, U.S. Pat. No. 4,272,855, issued Jun. 16, 1981, discloses the use of generally conical projections emanating from the surface of the implant. These projections may be perpendicular to the surface of the implant or may be extending outwardly at an angle between 50.degree. and 90.degree., with respect to the surface of the implant Frye teaches that an increase in the anchoring surface is a decisive feature which can influence and improve the bond between tissue and the implant. The projections described in Frye are generally regular in shape and devoid of comers and edges and have transition surfaces merging into the base level.
[0008] Van Kampen, U.S. Pat. No. 4,673,409, issued Jun. 16, 1987, discloses an implant having a surface comprising a multiplicity of spaced posts projecting from the implant surface for mating with bone material. The Van Kampen reference specifically teaches away from an edgeless surface as taught by the Frye reference. Van Kampen instructs that while a rounded surface minimizes the formation of stresses, it minimizes the total surface area that may be joined to the tissue, thus reducing the strength of the implant. Van Kampen discloses the use of regular posts which are roughly rectangular in cross-section. The posts are spaced at a regular interval and are formed by laser drilling.
[0009] It is evident from the teaching of these two references that there is some disagreement in the art regarding the best approach towards the preparation of an implant surface.
[0010] Another technique in the preparation of an implant surface is disclosed in Sump, U.S. Pat. No. 4,644,942, issued Feb. 24, 1987. The Sump reference discloses the use of a coating which is applied to the surface of the implant. The coating is comprised of a solid metallic powder and a solution of organic binders. A slurry formed of the two elements is applied to the surface of the implant and is permanently affixed thereto under controlled temperature and pressure conditions. The organic material is subsequently removed, leaving a porous, metallic coating on the surface of the implant.
[0011] Other techniques for applying a similar coating include plasma spray of a metallic material onto the surface of an implant resulting in a similar metallic irregular coating. While these porous coatings do provide an attachment surface into which bone may grow, these surfaces and the surface described in Noiles, U.S. Pat. No. 4,865,603, issued Sep. 13, 1989, exhibit significant shortcomings. The Noiles reference describes a surface in which furrows and depressions are cut or stamped into the surface of the implant. Each of these surfaces involves the addition of metallic material or the manipulation of the metallic surface of the implant. Each of these methodologies provides a surface that is subject to breakage and dislocation under stress. A metallic addition to the surface of the implant, even under rigorously controlled conditions, forms a joinder which is more easily broken than a singularly formed piece of metallic substrate. Similarly, the manipulation of the surface of the implant, even though formed of a single integral metal substrate, involves the stressing of the metallic surface which forms a locus for breakage when the implant is under a load.
[0012] In Wagner et al., U.S. Pat. Nos. 5,507,815 and 5,258,098, an attachment surface is provided in which a random irregular pattern is formed through a repetitive masking and chemical milling process. Surface material is removed from the implant without stress on the adjoining material, and the process provides fully dimensioned fillet radii at the base of the surface irregularities which is then adapted to receive the ingrowth of bone material when joined to bone during implantation. An irregular series of projections and depressions is formed to accommodate such ingrowth, providing a large surface area without any surface manipulations or additions.
[0013] The surface is prepared through an etching process which utilizes the random application of a maskant and subsequent etching of the metallic substrate in areas unprotected by the maskant. This etching process is repeated a number of times as necessitated by the amount and nature of the irregularities required for any particular application. The number of repetitions of the etching process is also utilized to control the surface features.
[0014] Cobalt-chromium alloys present a particular challenge for material removal utilizing this technique, primarily because of their high chemical inertness which makes them resistant to chemical etching. Wagner, et al., U.S. Pat. Nos. 5,922,029 and 6,193,762 disclose the preparation of a substrate through an electrochemical etching process which utilizes the random application of a maskant and subsequent electrochemical etching of the metallic substrate in areas unprotected by the maskant. This electrochemical etching process is repeated a number of times as necessitated by the amount and nature of the irregularities required for any particular application.
SUMMARY OF THE INVENTION
[0015] An attachment surface is provided in which a random irregular pattern is formed through a repetitive masking and chemical milling process. In some applications, such as the affixation of a composite material to a rigid or metallic substrate, the malleable composite material is molded into the irregularities of the substrate. As utilized in the production of some aircraft components, for example, a malleable, composite surface material is deposited upon a metal superstructure, which provides strength and support. The composite outer layer is designed to provide external characteristics, such as reduced air resistance or increased absorbability of electromagnetic radiation. When the substrate is a bone implant adapted to use in the human body, surface material is removed from the implant without stress on the adjoining material, and the process provides fully dimensioned fillet radii at the base of the surface irregularities which is then adapted to receive the ingrowth of bone material when joined to bone during implantation. An irregular series of projections and depressions is formed to accommodate such ingrowth, providing a large surface area without any surface manipulations or additions.
[0016] Where the invention employs chemical etching, control of the strength of the etchant material, the temperature at which the etching process takes place and the time allotted for such an etching technique permit fine control over the resulting surface produced by the process. The number of repetitions of the etching process is also utilized to control the surface features.
[0017] The particular maskant and etchant utilized for a given attachment surface is dictated by the base metal utilized for the implant while a titanium implant is contemplated as the best mode of practice in the invention, it is to be specifically understood that any base metal may be utilized as the implanted material. A change in the base metal would necessitate a change in the maskant and etchant. No limitation is to be inferred from the selection of titanium in the detailed description following nor in the selection of the particular maskant and etchant chemistries.
[0018] The surface of cobalt-chromium alloys are preferably prepared through an electrochemical etching process which utilizes the random application of a maskant and subsequent electrochemical etching of the metallic substrate in areas unprotected by the maskant. Control of the composition, temperature, and flow rate of the electrolyte, the work gap between the cathodic tool and the attachment surface of the anodic workpiece, the voltage difference between the cathodic tool and the anodic workpiece, the specific amperage, the temperature at which the electrochemical etching process takes place, and the time allotted for electrochemical etching permit fine control over the resulting surface produced by the process. The number of repetitions of the electrochemical etching process is also utilized to control the surface features.
[0019] The particular maskant and the parameters of the electrochemical etching process utilized for a given attachment surface is dictated by the base metal utilized for the implant. While a cobalt-chromium allow implant is contemplated as the best mode of practice in the invention, it is to be specifically understood that any base metal may be utilized as the implanted material. A change in the base metal may necessitate a change in the maskant, the electrolyte, and the parameters of the electrochemical etching process. No limitation is to be inferred from the selection of a cobalt-chromium allow in the detailed description which follows no in the selection of the particular maskant and of the particular parameters of the electrochemical etching process.
[0020] A final procedure provides the substrate with an enhanced surface texture having a plurality of micro-features that promote bone ingrowth or osseointegration. After completion of the initial masking and etching steps, the resulting surface is subjected to a blasting step in which a blast media is impinged upon the surface. One or more of the following five variables will, depending on the type of equipment being used, affect the surface texture produced and that must be taken into consideration during this blasting step: (1) the particular blast media chosen and the grit size thereof; (2) the duration of the blast; (3) the pressure of the blast stream; (4) the distance between the source of the blast media, such as a nozzle, and the surface being treated; and (5) the angle at which the source of the blast media, and thus the stream of the blast media, is directed toward the surface being treated. The blast media is selected according to the particular parameters of each application, depending upon the size and characteristic micro-features desired. The blast media is also selected in conjunction with a matched solvent that can dissolve or otherwise remove, without damage to the substrate material, any blast media material which is lodged into the substrate after blasting.
[0021] After the blasting step, the surface may be subjected to an optional cold flash step to remove stains in which the surface is immersed in a solvent or other bath for the purpose of cleaning the surface and removing any stains. Any special areas of the surface, such as threaded holes or trunnions, may be plugged or covered to prevent damage thereto.
[0022] The embedded particulate debris from the blast media is removed during a debris removal step. The debris removal step preferably follows the cold flash step, in which the surface is immersed in a solvent bath that leaches the embedded blast media particulate debris from the surface.
[0023] Performing the blasting and debris removal or passivation steps according to the present invention on the surface will result in a surface that includes a plurality of micro-features comprising recesses or indents that promote greater osseointegration.
[0024] These and other advantages and features of the present invention will be more fully understood upon reference to the presently preferred embodiments thereof and to the appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] [0025]FIG. 1 is a diagrammatic representation of a first cycle of the etching process, illustrating a first surface having a maskant applied thereto and a second surface indicating the resultant surface after etching.
[0026] [0026]FIG. 2 is a diagrammatic representation of the second cycle of the etching process, illustrating the second surface illustrated in FIG. 1 having a maskant applied thereto and a resultant third surface prepared by etching the masked second surface.
[0027] [0027]FIG. 3 is a diagrammatic representation of the third cycle of the etching process illustrating the resultant third etched surface of FIG. 2, also having a maskant applied thereto and a fourth surface prepared by etching the masked surface.
[0028] [0028]FIG. 4 is a photomicrograph of the chemically etched surface.
[0029] [0029]FIG. 5 is a diagrammatic representation, partially in cross section, of the arrangement of the elements of a typical electrochemical etching process.
[0030] [0030]FIG. 6 is a photomicrograph of the electrochemically etched surface.
[0031] [0031]FIG. 7 is a diagrammatic representation of surface shown in FIG. 3 following the blasting, cold flash and debris removal steps of the present invention.
[0032] [0032]FIG. 8 is a photomicrograph of a surface that has been prepared as shown in FIG. 3.
[0033] [0033]FIG. 9 is a photomicrograph of the surface shown in FIG. 8 following the blasting, cold flash and debris removal steps of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0034] A. Chemical Etching Embodiments:
[0035] In describing the preferred embodiment of the invention when chemical etching is employed and the best mode of carrying the invention out, the drawings and description refer to the use of a titanium alloy base metal. While titanium is the preferred embodiment for the implantable material, a number of other alloys may be utilized. Each of these different alloys will require a different maskant and etchant composition. Other than cobalt chromium, no specific details are given in the specification regarding the use of these other metals and etchants. It is, however, considered to be well within the knowledge of an experienced practitioner in the art to select an etchant once a base alloy has been identified. Furthermore, for the purposes of clarity, certain repetitive elements in the drawings have not been numerically identified for each and every occurrence. For example, a number of maskant points are shown on the surface diagrams. It is considered apparent from the drawings that the maskant points and other surface features of the etched implant are repeated and are readily identifiable without the aid of numeric identification for each feature. Only representative features and maskant points have therefore been identified.
[0036] Referring now to FIG. 1, an unfinished surface 1 is provided which diagrammatically represents the exterior surface of the device to be implanted. The letter identifiers on the right margin of the drawings are intended to provide a quick reference to the relative levels of etching. Unfinished surface 1 at level A is generally smooth and comprised of titanium metal or alloy such as Ti-6Al-4Va. As stated herein, a cobalt chromium alloy is also contemplated. A maskant is applied to the surface of the implant which is to be etched in a random fashion. Several methods may be utilized to accomplish the random spattering of the maskant on the surface. Among these are manually applying the maskant by brushing it using the tips of a hair-type brush or utilizing any type of shredded hair-like fibrous applicator dipped in the maskant material. Another method of application would be delivered in an air stream utilizing an air brush or paint gun.
[0037] The maskant must be chosen carefully in order to provide a substance which will cling tightly to the surface of the implant during manipulation of the implant and will also remain stable when the etchant solution is applied to the coated part. The maskant must also be removed with no residue once its function has been accomplished A particular problem encountered when utilizing maskants is the performance of the maskant at the boundaries of its application. The maskant should produce a sharply defined edge once the etching process has begun and not itself deteriorate during the etching process. This might permit partial degradation of the substrate in a masked area It should be noted, however, that some deterioration is found in any maskant use and does provide some of the particular surface features of the etched implant described later.
[0038] The surface 1 of the implant must be clean and grease-free and any oxidized material should be removed before the application of the maskant. This may be accomplished either mechanically, chemically or both. The surface may be cleaned mechanically utilizing a light abrasive blast of aluminum oxide particles or glass beads. Alternatively, blasting with any small solid particle which will not degrade the surface is contemplated A chemical agent such as methanol may be utilized alone or in conjunction with the blasting. Most maskants are very sensitive to the condition of the applied surface and both application and removal of the maskant may be affected by improper surface treatment. The maskant can be comprised of a number of materials including neoprene elastomers and isobutylene isoprene copolymers. The particular maskant should be selected based on the type of etchant utilized. The preferred maskant is AC-818C, an air-cured, general purpose, peelable coating produced by A.C. Products, Inc. of Placentia, Calif. The maskant is thinned utilizing perchlorethylene to 35-45 seconds utilizing a No. 5 Zahn cup. The maskant, if too thin, may be thickened to this viscosity by evaporation of the carrier. While the maskant is traditionally utilized in the 14-18 second range, it has been found that this thicker version produces superior results in terms of applying the maskant utilizing manual daubing or spray application techniques. It is to be specifically noted that the maskant is applied in a random spattered fashion allowing only a portion of the surface of the implant to be coated thereby. A random “polka dot” pattern is preferred in which each of the maskant points is of varying size and thickness when compared to the others. In some instances, the applied maskant may be partially abraded utilizing the grit blasting technique described previously for cleaning with an 80-120 mesh grit at 80-90 psi. to assist in providing an irregular maskant coating.
[0039] As shown in FIG. 1, a variety of applied maskant points 5 are illustrated. A particularly thick maskant agglomeration 10 is also illustrated. Other surface features of the applied maskant include an applied maskant plateau 15 and an applied maskant thin layer 20 . It is desirable to achieve a variety of sizes and thicknesses of maskant in order to obtain the proper random finished surface. As will be seen later, each of these particular maskant surface features produces a somewhat different etched result. An optional step of drying the maskant at an elevated temperature is also contemplated. Four to five minutes at 200.degree. F. is sufficient.
[0040] Referring now to the second illustration of FIG. 1, the etched result is illustrated, based on the applied maskant shown in the upper illustration. The unfinished surface indication line 24 , shown as a chain, indicates the original level identified by the letter A at which the surface began. The first etched surface 25 identified by the letter B shows the resultant etched surface. While a number of etchants could be utilized, the particular chemistry adopted for the preferred embodiment utilizes a standard 30% nitric acid—6% hydrofluoric acid combination which is commonly marketed and well known in the art. The etchant is applied at 110.degree. F. for approximately 4 minutes to achieve a desired 0.008-0.010 inch etch depth. This time period or the strength of the etchant solution may be adjusted upwardly or downwardly to achieve a heavier or lighter etching. The etching is halted in a water bath or spray.
[0041] The maskant material may be removed in a variety of ways. The material may be removed mechanically or chemically. Depending on the size and number of coated objects, mechanical brushing or blasting of the maskant will peel it off. Additionally, the use of nitric acid is contemplated to dissolve the maskant material.
[0042] Referring again to the second illustration of FIG. 1, a number of surface features may be identified. A primary plateau 30 corresponds to the applied maskant plateau 15 illustrated in the top drawing. The heavy maskant coat completely protects the implant surface, preventing any metallic material from being removed at this point. A secondary plateau 35 corresponds to the thin layer 20 illustrated in the above drawing. The intermediate height of the secondary plateau between levels A and B indicates that the maskant performed for some period during the etching cycle but failed at an intermediate time allowing some of the alloy to be etched away. A small promontory, third from the left as shown in FIG. 1, also illustrates a small secondary plateau 35 . Gradually sloped feature 40 corresponds to a gradually tapering maskant coverage which partially protects the underlying substrate during the etching cycle. A highly sloped feature 44 indicates a thicker maskant coating which enjoyed a highly defined perimeter before etching. A medium sloped feature 45 indicates a maskant condition intermediate the two previously described. The extremes of the etching are indicated by unetched level 46 and first etched level 47 which illustrate the effect of complete maskant coating versus no maskant coating. It should be noted that the base of each surface feature provides full dimensionally filleted radii.
[0043] [0043]FIG. 2 also employs two illustrations to display the effects of a second masking/etching cycle. The upper illustration corresponds to the second illustration of FIG. 1, the lowest extreme being found at the level indicated as B. The maskant is again applied to a clean and prepared surface in a random fashion according to the same techniques described with reference to FIG. 1. As before, a randomized pattern is preferable in which a wide variety of maskant surface features is achieved. Second applied maskant points 50 illustrate a variety of positions in which the maskant may be applied to the now irregular surface features of first etched surface 25 .
[0044] Moving to the second illustration of FIG. 2, the first etched surface indication line 55 is shown in chain line to indicate the previous surface prior to the second etching cycle. The second etching cycle is performed under identical conditions as that described with reference to FIG. 1 to again achieve a 0.008-0.010 inch maximum etch. Second etched surface 60 is shown at level C, indicating a resultant etched surface. As previous described, the number of surface features are illustrated corresponding to the characteristics of the applied maskant. A highly sloped surface feature 44 corresponds again to a sharply defined and relatively thick application of maskant while a gradually sloped surface feature 40 corresponds to a gradually thinning maskant application. This feature is particularly visible in the two illustrations contained in FIG. 2 in which the gradual thinning of the maskant application is particularly exaggerated.
[0045] As can be seen in the second illustration of FIG. 2, three major levels of surface features are illustrated with a few intermediate features present to demonstrate the effects of partial maskant failure. A few points remain at unetched level 46 indicating maskant coverage during both etchant cycles. Some points are illustrated at first etched level 47 indicating maskant coverage during one of the two cycles, while points located at second etched level 75 have been exposed to the etchant during both of the etching cycles. The increasing level of complexity of surface forms is apparent with comparison between FIGS. 1 and 2.
[0046] [0046]FIG. 3 is essentially a repetition of FIG. 2 having an upper illustration showing the application of third applied maskant points 80 to the now highly featured second etched surface 60 at level C. The increasing complexity of the surface of the etched device contributes also to the complexity of the maskant forms when applied to the irregular surface. The second illustration of FIG. 3 is shown to demonstrate the effect of a less rigorous etching cycle, being roughly one-half of the depth shown in FIGS. 1 and 2. The number and length of each etching cycle is purely dependent on the complexity of features required by the application and may be performed by any order. As shown in the second illustration of FIG. 3, a gradually sloped surface feature 40 retains its gradually sloped character from one cycle to the next when not covered by a maskant. This is to illustrate the consistent and uniform attack on the surface by the etchant solution. Highly sloped surface feature 44 again illustrates the effect of a highly stable maskant agglomeration while medium sloped surface feature 45 again demonstrates an intermediate condition. As illustrated in the second drawing of FIG. 3, four major surface levels are illustrated. Points at unetched level 46 are still apparent although fewer in number and relatively rare. A number of plateaus remain at first etched level 47 and second etched level 75 . Those areas which have been exposed during all three etchant cycles enjoy depressions at third etched surface 100 corresponding to level D in FIG. 3. These levels correspond to areas which have had coverage during all three cycles, two cycles, one cycle and no cycles, respectively. The result as shown by third etched surface 90 is of a highly non-uniform featured surface which, compared with its length, also exhibits a large surface area. The different levels of depression and protrusion are particularly adapted to permit the ingrowth of bone and to allow for a firm anchoring of the bone along the surface of the implant structure.
[0047] [0047]FIG. 4 illustrates a sample resultant surface. While specific identification of the surface features is difficult, a long ridge line is visible extending diagonally from upper left to lower right. A first level of three plateaus is visible at the center of the Figure, and lower level features extend outwardly in the upper right and lower left directions. All surface features are fully filleted and irregularly shaped to promote bone ingrowth.
[0048] B. Electrochemical Etching Embodiments:
[0049] In describing the preferred embodiment of the invention when electrochemical etching is employed and the best mode of carrying the invention out, the drawings and description refer to the use of a cobalt-chromium alloy base metal. While cobalt-chromium alloy is the preferred embodiment for the implantable material, a number of other alloys may be utilized in connection with electrochemical etching. Each of these different alloys may require a different maskant and electrochemical etching conditions. While no specific details are given in the specification regarding the use of these other metals and electrochemical etching conditions, it is considered to be well within the knowledge of an experienced practitioner in the art to select the appropriate electrochemical etching conditions once a base alloy has been identified. Furthermore, for the purposes of clarity, certain repetitive elements in the drawings have not been numerically identified for each and every occurrence. For example, a number of maskant points are shown on the surface diagrams. It is considered apparent from the drawings that the maskant points and other surface features of the etched implant are repeated and are readily identifiable without the aid of numeric identification for each feature. Only representative features and maskant points have therefore been identified.
[0050] Referring now to FIG. 1, an unfinished surface 1 is provided which diagrammatically represents the exterior surface of a device, such as a bone implant, that is to be joined to a second material. The letter identifiers on the right margin of the drawings are intended to provide a quick reference to the relative levels of electrochemical etching. Unfinished surface 1 at level A is generally smooth and comprised of cobalt-chromium alloy such as the cobalt-28 chromium-6 molybdenum alloy described in Table 1. A maskant is applied to the surface of the device which is to be electrochemically etched in a random fashion. Several methods may be utilized to accomplish the random spattering of the maskant on the surface. Among these are manually applying the maskant by brushing it using the tips of a hair-type brush or utilizing any type of shredded hair-like fibrous applicator dipped in the maskant material. Another method of application would be delivered in an air stream utilizing an air brush or paint gun.
TABLE I Composition of Molybdenum Cobalt-28 Chromium-6 Alloy minimum %* maximum %* tolerance +/− %* Chromium 26.0 30.0 0.30 Molybdenum 5 7 0.15 Nickel — 1.0 0.05 Iron — 0.75 0.03 Carbon — 0.35 0.02 Silicon — 1.0 0.05 Manganese — 1.0 0.03 Nitrogen — 0.25 0.03 Cobalt balance — —
[0051] The maskant must be chosen carefully in order to provide a substance which will cling tightly to the surface of the device during manipulation of the device and will also remain stable when the etchant solution is applied to the coated part. The maskant must also be removed with no residue once its function has been accomplished. A particular problem encountered when utilizing maskants is the performance of the maskant at the boundaries of its application. The maskant should produce a sharply defined edge once the electrochemical etching process has begun and not itself deteriorate during the electrochemical etching process. This might permit partial degradation of the substrate in a masked area It should be noted, however, that some deterioration is found in any maskant use and does provide some of the particular surface features of the electrochemical etched device described later.
[0052] The surface 1 of the device must be clean and grease-free and any oxidized material should be removed before the application of the maskant This may be accomplished either mechanically, chemically or both. The surface may be cleaned mechanically utilizing a light abrasive blast of 80 to 120 grit aluminum oxide particles or glass beads. Alternatively, blasting with any small solid particle which will not degrade the surface is contemplated. All blasting residue is to be removed by brushing. A chemical agent such as acetone may be utilized alone or in conjunction with the blasting to clean the surface 1 . Most maskants are very sensitive to the condition of the applied surface and both application and removal of the maskant may be affected by improper surface treatment.
[0053] The maskant can be comprised of a number of materials including neoprene elastomers and isobutylene isoprene copolymers. The preferred maskant for use with cobalt-chromium alloys is an alkaline soluble, air-curable phenol-formaldehyde resin maskant material such as Hysol ER1006 produced by The Dexter Corporation, Industry, Calif.
[0054] It is to be specifically noted that the maskant is applied in a random spattered fashion allowing only a portion of the surface of the device to be coated thereby. A random “polka dot” pattern is preferred in which each of the maskant points is of varying size and thickness when compared to the others. In some instances, the applied maskant may be partially abraded utilizing the grit blasting technique described previously for cleaning with an 80-120 mesh grit at 80-90 psi to assist in providing an irregular maskant coating.
[0055] The viscosity of the maskant should be adjusted to a level that promotes both the application of the maskant in a random spattered panern and the proper curing of the maskant. The maskant may be thinned to the optimum viscosity by the addition of its carrier fluid. If the maskant is too thin, the maskant may be thickened to a lower viscosity by evaporation of its carrier fluid. For the Hysol ER1006 maskant, the optimum viscosity is about 60-66 seconds as measured utilizing a No. 5 Zahn cup.
[0056] After the maskant has been applied in a random spattered pattern, it is cured. For example, the Hysol ER1006 maskant is preferably cured for a minimum of about 20 minutes at between about 200-250.degree. F. and then air cooled to room temperature.
[0057] As shown in FIG. 1, a variety of applied maskant points 5 are illustrated. A particularly thick maskant agglomeration 10 is also illustrated. Other surface features of the applied maskant include an applied maskant plateau 15 and an applied maskant thin layer 20 . It is desirable to achieve a variety of sizes and thicknesses of maskant in order to obtain the proper random finished surface. As will be seen later, each of these particular maskant surface features produces a somewhat different electrochemical etching result.
[0058] [0058]FIG. 5 diagrammically shows the arrangement of the elements of a typical electrochemical etching process. After the maskant material has been applied and cured, the exposed portion 120 of the attachment surface 108 of workpiece 110 is ready to be electrochemically etched. The exposed portion 120 of the attachment surface 108 is that portion of the attachment surface 108 which is not covered by maskant deposits 116 . A tank 126 may be used to submerge the tooling 106 and the workpiece 110 under an electrolyte fluid 102 . The electrolyte fluid 102 fills the work gap 104 between the tooling 106 and the attachment surface 108 of the workpiece 110 . The electrolyte fluid 102 is pumped at controlled rate through a passageway 114 in the tooling 106 and out through an orifice 118 into the work gap 104 . The tooling 106 is in electrical connection with the negative terminal 124 of a direct current power supply 112 and thus becomes the cathode of the electrochemical etching process. The workpiece 110 is in electrical connection with the positive terminal 122 of the same direct current power supply 112 and thus becomes the anode of the electrochemical etching process.
[0059] The electrolyte fluid 102 for electrochemically etching a cobalt-chromium alloy is preferably a solution containing the proportions of one pound each of NaCl and NaNO.sub.3 dissolved in one gallon of water. One skilled in the art of electrochemically etching metals will recognize and employ the appropriate electrolyte fluid 102 to be used for the type of metal of a particular workpiece 110 . Control of the flow rate of the electrolyte fluid 102 through the work gap 104 is important because the electrolyte fluid 104 must adequately remove both the heat and the reaction products of the electrochemical process. The optimum flow rate level is related to the amount of current employed. Higher ratios of flow rate to current give better removal of heat and reaction products. For the electrochemical etching a cobalt-chromium alloy, for example, the electrolyte fluid 102 should flow through the work gap 104 at a rate of about 0.15-0.5 gallons per minute per 100 amps and have a temperature of between about 100-130.degree. F. One skilled in the art of electrochemically etching metals will be able to determine the proper values of these parameters to use with a particular application.
[0060] The tooling 106 may be made from any material suitable for use in electrochemical etching such as copper, nickel, or an alloy of tungsten-copper. The tooling 106 should be configured so that the work gap 104 between the tooling 106 and the attachment surface 108 is substantially uniform. This is accomplished by making the tooling 106 substantially conformal to the attachment surface 108 . Preferably, the work gap 104 is between about 0.020-0.250 inches, more particularly between about 0.060-0.120 inches. One skilled in the art of electrochemically etching metal will be able to determine the proper work gap 104 to use for a particular application. A direct current voltage difference between the tooling 106 and the attachment surface 108 of between about 8V-24V and a specific amperage of at least about 50 amps per square inch of exposed portion 120 of the attachment surface 108 are to be maintained during the electrochemical etching of a cobalt-chromium workpiece 110 . Preferably, the direct current voltage difference between the tooling 106 and the attachment surface 108 is between about 12-18V and the specific amperage is about 75-120 amps per square inch of exposed portion 120 of the attachment surface 108 . The values of these parameters for use with other materials are readily determinable by one skilled in the art of electrochemical etching metals. The stated conditions will produce a metal removal rate of about 0.003 inch per minute when the workpiece 110 material is a cobalt-chromium alloy.
[0061] Referring now to the second illustration of FIG. 1, the electrochemically etched result is illustrated, based on the applied maskant shown in the upper illustration. The unfinished surface indication line 24 , shown as a chain, indicates the original level identified by the letter A at which the surface began. The first electrochemically etched surface 25 identified by the letter B shows the resultant electrochemically etched surface. The electrochemical etching is continued until a desired etch depth of about 0.001-0.010 inch is achieved. Preferably, the etching is continued until a desired etch depth of about 0.002-0.007 inches is achieved. The time period and other parameters of the electrochemical etching process, particular the specific amperage, may be adjusted upwardly or downwardly to achieve a heavier or lighter etching. The electrochemical etching process is halted by removing the voltage difference between the tooling 106 and the workpiece 110 .
[0062] The maskant material on the attachment surface 106 is removed after each electrochemical etching step. The maskant material may be removed in a variety of ways. The maskant material may be removed mechanically or chemically. Depending on the size and number of coated objects, mechanical brushing or blasting of the maskant may peel it off. In the preferred embodiment of the invention using a cobalt-chromium alloy workpiece and the Hysol ER1006 maskant material, the workpiece is immersed in an aqueous solution of an alkaline cleaner to dissolve the maskant material. Preferably, the temperature of the alkaline cleaner solution is between about 80-145.degree.F. The immersion time is about 5 to 10 minutes or until the maskant is removed. Water blasting is employed to remove any clinging maskant material which was softened by the alkaline cleaning solution.
[0063] Preferably, the masking/electrochemical etching process is repeated three times, though useful attachment surfaces may be obtained through the use of fewer and more numerous cycles. The amount of material removed during each cycle is to be determined by the particular application. Preferably, substantially the same amount of material, as measured by depth of material removal, is removed in each cycle. When multiple masking/electrochemical etching cycles are employed, it is preferable that the attachment surface 106 be blasted with 80 to 120 mesh alumina grit prior to the application of the maskant material so as to promote the adhesion of the maskant material.
[0064] Referring again to the second illustration of FIG. 1, a number of surface features may be identified. A primary plateau 30 corresponds to the applied maskant plateau 15 illustrated in the top drawing. The heavy maskant coat completely protects the device surface, preventing any metallic material from being removed at this point A secondary plateau 35 corresponds to the thin layer 20 illustrated in the above drawing. The intermediate height of the secondary plateau between levels A and B indicates that the maskant performed for some period during the electrochemical etching cycle but failed at an intermediate time allowing some of the alloy to be etched away. A small promontory, third from the left as shown in FIG. 1, also illustrates a small secondary plateau 35 . Gradually sloped feature 40 corresponds to a gradually tapering maskant coverage which partially protects the underlying substrate during the electrochemical etching cycle. A highly sloped feature 44 indicates a thicker maskant coating which enjoyed a highly defmed perimeter before the electrochemical etching. A medium sloped feature 45 indicates a maskant condition intermediate the two previously described. The extremes of the electrochemical etching are indicated by unetched level 46 and first electrochemically etched level 47 which illustrate the effect of complete maskant coating versus no maskant coating. It should be noted that the base of each surface feature provides full dimensionally filleted radii.
[0065] [0065]FIG. 2 also employs two illustrations to display the effects of a second masking/electrochemical etching cycle. The upper illustration corresponds to the second illustration of FIG. 1, the lowest extreme being found at the level indicated as B. The maskant is again applied to a clean and prepared surface in a random fashion according to the same techniques described with reference to FIG. 1. As before, a randomized pattern is preferable in which a wide variety of maskant surface features is achieved. Second applied maskant points 50 illustrate a variety of positions in which the maskant may be applied to the now irregular surface features of first electrochemically etched surface 25 .
[0066] Moving to the second illustration of FIG. 2, the first electrochemically etched surface indication line 55 is shown in chain line to indicate the previous surface prior to the second electrochemical etching cycle. The second electrochemical etching cycle is performed under identical conditions as that described with reference to FIG. 1 to again achieve an approximately 0.001-0.010 inch electrochemical etch. Second electrochemically etched surface 60 is shown at level C, indicating a resultant electrochemically etched surface. As previous described, the number of surface features are illustrated corresponding to the characteristics of the applied maskant. A highly sloped surface feature 44 corresponds again to a sharply defined and relatively thick application of maskant while a gradually sloped surface feature 40 corresponds to a gradually thinning maskant application. This feature is particularly visible in the two illustrations contained in FIG. 2 in which the gradual thinning of the maskant application is particularly exaggerated.
[0067] As can be seen in the second illustration of FIG. 2, three major levels of surface features are illustrated with a few intermediate features present to demonstrate the effects of partial maskant failure. A few points remain at unetched level 46 indicating maskant coverage during both electrochemical etching cycles. Some points are illustrated at first electrochemically etched level 47 indicating maskant coverage during one of the two cycles, while points located at second electrochemically etched level 75 have been exposed to the electrochemical etching process during both of the electrochemical etching cycles. The increasing level of complexity of surface forms is apparent with comparison between FIGS. 1 and 2.
[0068] [0068]FIG. 3 is essentially a repetition of FIG. 2 having an upper illustration showing the application of third applied maskant points 80 to the now highly featured second electrochemically etched surface 60 at level C. The increasing complexity of the surface of the electrochemically etched device contributes also to the complexity of the maskant forms when applied to the irregular surface. The second illustration of FIG. 3 is shown to demonstrate the effect of a less intense electrochemical etching cycle, being roughly one-half of the depth shown in FIGS. 1 and 2. The number and intensity of each electrochemical etching cycle is dependent on the complexity of features required by the application and may be performed in any order. As shown in the second illustration of FIG. 3, a gradually sloped surface feature 40 retains its gradually sloped character from one cycle to the next when not covered by a maskant. This is to illustrate the consistent and uniform attack on the surface by the electrochemical etching process. Highly sloped surface feature 44 again illustrates the effect of a highly stable maskant agglomeration while medium sloped surface feature 45 again demonstrates an intermediate condition. As illustrated in the second drawing of FIG. 3, four major surface levels are illustrated. Points at unetched level 46 are still apparent although fewer in number and relatively rare. A number of plateaus remain at first electrochemically etched level 47 and second electrochemically etched level 75 . Those areas which have been exposed during all three electrochemical etch process cycles enjoy depressions at third electrochemically etched surface 100 corresponding to level D in FIG. 3. These levels correspond to areas which have had coverage during all three cycles, two cycles, one cycle and no cycles, respectively. The result, as shown by third electrochemically etched surface 90 , is a highly non-uniform featured surface which, compared with its length, also exhibits a large surface area. The different levels of depression and protrusion are particularly adapted to permit the ingrowth of bone and to allow for a firm anchoring of the bone along the surface of an implant structure. The different levels of depression and protrusions are also particular adapted to permit the inflow and anchoring of adhesives.
[0069] [0069]FIG. 6 illustrates a sample resultant surface. All surface features are fully filleted and irregularly shaped to promote bone ingrowth and the inflow of adhesives.
[0070] According to a preferred embodiment of the present invention, a method is provided for providing an unfinished surface 1 , as described in connection with FIGS. 1 through 6, with an enhanced surface texture having a plurality of micro-features that promote bone ingrowth or osseointegration. According to the method, surface 1 is first subjected to a predetermined number of masking and chemical or electrochemical etching steps as shown and described in conjunction with FIGS. 1 through 6. Depending on the number of masking and chemical or electrochemical etching steps that are performed, a surface texture such as shown in FIGS. 1, 2 or 3 will result. After completion of these steps, the resulting surface is then subjected to a blasting step in which a blast media is impinged upon the surface. The blasting step may be performed in conjunction with any known equipment typically used for blasting, including, but not limited to, a blast cabinet having an air gun or nozzle, a wheel abrader machine, or gas jet shot equipment that sputters the blast media in the direction of the part to be treated. One or more of the following five variables will, depending on the type of equipment being used, affect the surface texture produced and that must be taken into consideration during this blasting step: (1) the particular blast media chosen and the grit size thereof; (2) the duration of the blast; (3) the pressure of the blast stream; (4) the distance between the source of the blast media, such as a nozzle, and the surface being treated; and (5) the angle at which the source of the blast media, and thus the stream of the blast media, is directed toward the surface being treated. One preferred embodiment incorporates blast media of any metallic material that can be dissolved or otherwise removed without damage to the substrate material. One preferred solvent is nitric acid, which may be utilized to dissolve materials such as steel, aluminum or copper.
[0071] Preferably, the blast media is a fractured or split shot media having a grit range of G10 to G120. Acceptable blasting durations are in the range of 1 to 30 seconds, acceptable blasting pressures are in the range of 20 to 120 psi, acceptable distances from the source may be as large as 10 or 12 inches, and acceptable incident angles range from 5 to 90 degrees, with 90 degrees being the angle at which the source of blast media is pointed directly at the surface. As will be appreciated by those of skill in the art, the most suitable values for each of these parameters will vary depending on the particular type of material making up surface 1 and the values chosen for the other parameters. According to one embodiment of the present invention, G40 fractured steel shot is used as the blast media in a blast cabinet for a duration of 5 to 15 seconds, most preferably 2 to 6 seconds, at a pressure of approximately 80 psi, at a distance of 2 to 4 inches and an incident angle of 40 to 50 degrees. According to a most preferred embodiment, this preferred blasting step is performed after the surface has been masked and chemically or electrochemically etched as described herein three times, removing 0.005″ of material in the unmasked areas during each etching step.
[0072] After the blasting step, the surface is subjected to a cold flash step to remove stains in which the surface is immersed in a hydrofluoric acid/nitric acid bath for at least the minimum amount of time required to ensure a bright, stain free surface. Preferably, the hydrofluoric acid/nitric acid bath is maintained at room temperature and consists of the following per 100 gallon solution: 11 gallons nitric acid 42 Degrees Baume, 6.5 gallons hydrofluoric acid 70%, 4 pounds titanium (CP), balance deionized water. In addition, the cold flash step preferably removes no more than 0.0002 inches of material from the surface by controlling the time in which the surface is immersed in the bath. Any special areas of the surface, such as threaded holes or trunnions, may be plugged or covered to prevent damage thereto.
[0073] As will be further appreciated by those of skill in the art, the blasting step will result in the surface being contaminated with embedded blast media particulate debris. According to the method of the present invention, this embedded particulate debris is removed during a debris removal step, which in the above embodiment is a nitric acid passivation step. Those skilled in the art will appreciate that in alternative embodiments, the solvent is intended to be matched to the blast media such that the blast media embedded in the substrate is completely removed by the solvent without deleterious effect on the substrate. The debris removal step preferably follows the cold flash step, in which the surface is immersed in a nitric acid bath that leaches the embedded steel particulate debris from the surface. According to a preferred embodiment, the nitric acid bath consists of nitric acid, 40% by volume, in deionized water, and the surface is immersed for no less than 6 hours. Also, the nitric acid bath is preferably maintained at room temperature at a specific gravity between 1.175 and 1.225 (60°/60°). The surface is then rinsed in deionized water and air-dried.
[0074] Performing the blasting and passivation steps according to the present invention on the surface shown in FIG. 3 will result in a surface such as that shown in FIG. 7 that includes a plurality of micro-features 150 comprising recesses or indents that promote greater osseointegration. FIG. 8 is a photomicrograph of a titanium surface that has been masked and chemically etched as described herein three times, removing approximately 0.005 inches of material in the unmasked areas during each etching step. FIG. 9 is a photomicrograph of the same surface after the preferred blasting, cold flash and passivation steps described herein have been performed.
[0075] Although particular embodiments of the present invention have been illustrated in the accompanying drawings and described in the foregoing detailed description, it is to be further understood that the present invention is not to be limited to just the embodiments disclosed, but that they are capable of numerous rearrangements, modifications and substitutions. | An attachment surface for an implantable device has an irregular pattern formed through a process including masking, chemical or electrochemical etching, blasting and debris removal steps. Surface material is removed from the implant surface without stress on the adjoining material and the process provides fully dimensional fillet radii at the base of the surface irregularities. This irregular surface is adapted to receive the ingrowth of bone material and to provide a strong anchor for that bone material which is resistant to cracking or breaking. The surface is prepared through an etching process which utilizes the random application of a maskant and subsequent etching in areas unprotected by the maskant. This chemical etching process is repeated a number of times as necessitated by the nature of the irregularities required in the surface. The blasting and debris removal steps produce microfeatures on the surface that enhance the ingrowth of bone material. | 0 |
This application is divisional of U.S. patent application Ser. No. 09/342,876, which filed Jun. 29, 1999 claims the benefit of U.S. Provisional Application No. 60/090,968 filed Jun. 29, 1998.
BACKGROUND AND SUMMARY OF THE INVENTION
1. Technical Background
The present invention relates generally to medical devices, and more particularly to a vascular medical device.
2. Discussion
Vascular filters may be used for a variety of therapeutic applications, including implantable vena cava filters for capturing thrombus, or for distal protection during a vascular procedure.
Numerous different vascular filters are known of various types and designs. Prior filters are generally designed for either temporary use, such as may be provided on a catheter or provided with a mechanism for retrieving, the filter, or for permanent implantation. Either a permanent or a temporary filter maybe preferred for a specific situation, given the specific therapeutic conditions and the properties of the filter.
The present invention relates to a filter system including a vascular filter that can be placed inside a body passage or cavity, such as a blood vessel, through a catheter consisting of a tubular basic body with a distal end, a proximal end and a catheter lumen extending in between the ends. The vascular filter can be received in a compressed state inside the catheter lumen, and the catheter is provided with an ejection device which can be used to eject the vascular filter from the distal end of the catheter.
Vascular filters of the type that are implanted in a patient's body vessel are often made of an elastic or so-called “memory” material. The vascular filter is positioned by using an ejection member to push the filter from the open distal tip of the catheter into the blood vessel.
Many prior vascular filters expand resiliently from the compressed state inside the catheter lumen to an enlarged or deployed state, when released or deployed at the desired site for treatment.
However, it is desirable to provide a filter capable of being implanted for a selectively variable duration. For example, a vascular filter according to the present invention might have a design such that the filter is deployed through a catheter, and then the filter may be transformed at a selected time later to provide an open “through lumen”.
The present invention provides a novel vascular filter having a hybrid configuration, which is capable of being transformed to provide a through lumen at a time selected later.
Accordingly, it is desirable to provide a vascular filter capable of being implanted in an initial “filtering” configuration. The device may be monitored periodically for a time, until the physician decides to convert the implanted filter into a stent, for example. The filter is thus designed to selectively metamorphose into a second stent or graft configuration, providing a resilient tubular scaffold having and tending to maintain an open lumen through the body passageway.
Of course, the present invention relates broadly to vascular filters that are convertible into an open lumen device. The present invention may therefore be practiced in a multitude of different designs and variations which will occur to an average practitioner in the art.
These and various other objects, advantages and features of the invention will become apparent from the following description and claims, when considered in conjunction with the appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic side elevational view of a convertible vascular filter, arranged according to one embodiment of the principles of the present invention;
FIGS. 2 and 3 are diagrammatic side elevational views of the convertible vascular filter, showing operation of the device during transformation;
FIG. 4 is a diagrammatic side elevational view of the vascular filter of FIG. 1, after transformation into a stent;
FIG. 4A is an axial longitudinal view of the stent of FIG. 4;
FIG. 5 shows a convertible vascular filter arranged according to the principles of the present invention in an initial filter configuration before being trasformed into a stent configuration;
FIG. 6 shows the vascular filter of FIG. 5, after a catheter has snared a proximal end hook of the filter; and
FIG. 7 shows the vascular filter of FIG. 6, after the proximal end of the filter has been opened, and illustrating the distal end hook being snared;
FIG. 8 shows the vascular filter of FIG. 7, after a catheter has snared a distal end hook of the filter;
FIG. 9 shows the convertible vascular filter of FIGS. 5-8, after being transformed into a tubular stent;
FIG. 10 is a partial view of the catheter and snare system of FIGS. 5-8 in greater detail;
FIG. 11 is a side elevational view of yet another embodiment of a convertible vascular filter, arranged according to the present invention; and
FIG. 12 is a side elevational view of the vascular filter of FIG. 11, showing the filter being converted into a stent by inflating the end portions with a balloon catheter.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The following description of the preferred embodiments of the present invention is merely illustrative in nature, and as such it does not limit in any way the present invention, its application, or uses. Numerous modifications may be made by those skilled in the art without departing from the true spirit and scope of the invention.
Referring to the drawings, in FIG. 1 a vascular fiter 10 according to the present invention has been illustrated. According to the specific embodiment shown in FIGS. 1-4, the filter 10 has several longitudinal ribs 12 supporting a first and second filter element or lattice 14 and 16 . For the sake of drawing clarity, all of the ribs and the wires of filter elements have not been illustrated. Of course, there may be many filter elements or lattices, arranged in whatever preferred design is selected. In the arrangement shown in FIGS. 1-4, the filter elements 14 and 16 have a minimal number of converging wires.
One benefit of a design having more than one filter element coupled by longitudinal ribs is that the vascular filter 10 tends to deploy and align itself properly with the axis of the body passage or blood vessel.
In addition, the filter may be provided with a set of circumferential resilient supports, adapted to both hold the vascular filter in place, and also to ultimately hold open the body passage when the filter is converted into a stent.
As shown in FIG. 1, the filter elements 14 and 16 are held together by removable clamps 22 . The clamps 22 are locked by pins 26 , and both the pins 26 and clamps 22 have removal hooks 18 and 20 attached.
Before the filter is delivered and deployed in the patient's body, it is first loaded into a delivery catheter. In the distal tip of the catheter, at least one vascular fiter is initially arranged in a compressed state. As an alternative, it is also possible that the filter is pushed along the entire length of the catheter from its proximal end to its distal end, after the catheter distal end has been advanced to the desired position. Preferably the filter is packed, in a compressed state, in transport packaging forming a covering. The vascular filter may be ejected from the distal tip of the catheter by a pushing wire and introduced into a blood vessel. Due to the release from the radially compressive force imposed by the catheter lumen at the distal tip of the catheter, the vascular filter will tend to expand resiliently to obtain an expanded shape. Liquid inside the blood vessel can pass through in an unimpeded fashion, but thrombus will tend to be intercepted by one of the two filter lattices.
An advantage of this configuration is that it provides two filter elements for intercepting thrombus moving inside a blood vessel, which may be more effective than one. In addition, due to the configuration of the ribs which extend along the internal wall of the blood vessel, no free ends are presented which might damage the internal wall of the blood vessel. The configuration of the vascular filter according to the embodiment illustrated is consequently designed so as to minimize any distress or damage to the blood vessel inside of which it has been arranged. As filter elements have been arranged on either side of the ribs and consequently a symmetrical shape has been obtained, there is no difference in the performance of the filter regarding the direction from which this vascular filter 10 has been placed inside the blood vessel.
As has been illustrated, the grid shape of each of the filters is such that each of the ribs is connected with a number of the components of these filters. Furthermore, each of the ribs is connected with both filters on either side. Due to this configuration, an added safety feature is that the filter has a fail-safe design.
In addition, tipping over or misaligmnent of either filter is less likely due to the more or less tubular shape into which the ribs have been arranged so that positioning of the vascular filter 10 inside the blood vessel can take place with unprecedented stability and reliability.
The vascular filter 10 is preferably made of a very resilient material, like nitinol. Following the ejection from the distal tip of the catheter, filter 10 can expand and will be pressed against the internal wall of the blood vessel.
When the physician decides to transform the vascular filter into a stent, a catheter may be reinserted to a position near the filter. A guidewire with a hook can be used to pull the hook 20 attached to a locking pin 26 . With the removal of the locking pin 26 , the ends of the filter element collapse together, and the clamp 22 loses its purchase. The clamp 22 and locking pin 26 are then pulled by their attached hooks 18 and 20 out through the catheter, and the members forming filter elements 14 and 16 resiliently expand as in FIGS. 2-3. The resulting configuration is one of a resilient tubular stent 28 defining an open through lumen, as shown in FIGS. 4 and 4A.
The locking pin 26 and clamp 22 at the other end of the filter may be accessed and removed by approaching the filter from the other vascular direction.
Another embodiment of the present invention is illustrated in FIGS. 5-10. The vascular filter 30 is shown having a “lobster pot” configuration including a number of longitudinal ribs 42 , as well as transverse or circumferential support members.
A pair of hooks 38 and 40 are provided at the proximal and distal ends for the filter. The hooks 38 and 40 may of course be formed as a shaped extension of one of the filter wires or ribs 42 . As shown in FIG. 5, both hooks 38 and 40 preferably extend from a center region of a filter element 44 in a proximal direction. This feature offers the advantage of releasing both filter elements 44 into the stent configuration with a catheter approaching the filter from only one direction.
The wires of each filter lattice 44 are held together by closing wires 52 .
A catheter 32 and snare loop 34 may be used to convert the filter 30 into a stent configuration. After the snare 34 catches the proximal hook 38 , it pulls the hook 38 and the closing wires 52 at the ends of the filter wires into the distal end of the catheter 32 , as shown in FIG. 6 . Inside the catheter distal end are a series of cutting members or knives 50 , adapted to cut the closing wires 52 of the filter 30 . When the closing wires 52 are severed, the filter wires resiliently expand to form the desired tubular stent configuration. Of course, the hooks 38 and 40 are specifically arranged to be flat against the body vessel wall in the stent configuration.
As shown in FIGS. 7-8, the distal end of the filter is released in a similar manner, and the resulting stent is shown in FIG. 9 .
Yet another embodiment of the present invention is shown in FIGS. 11-12. The vascular filter is a hybrid combination of a central resilient “self-expanding” portion 54 flanked by two “balloon expandable” portions 62 .
The self-expanding central portion 54 always tends to resiliently expand, being made for example of nitinol, while the balloon expandable portions 62 tend to remain compressed until forcibly expanded, being made for example of stainless steel.
The self-expanding filter portion 54 is permanently affixed to the balloon expandable stent portions 62 , which may be affixed to a pair of hooks or loops 60 for maneuvering the device. The components may be affixed for example by welding.
When the physician decides to convert the filter into a stent, the balloon expandable stent or collar portions 62 are forcibly expanded such as by a balloon 66 of a balloon catheter 68 , as shown in FIG. 12 .
One advantage of the embodiment of a vascular filter according to the present invention is that the loop 60 may be used to later remove the vascular filter. Loops 60 can thus serve as a target for a hook-shaped extraction element, in order to remove the vascular filter. The hook-shaped extraction body (not shown) may engage the loop, and pull the entire vascular filter back into a catheter enveloping the extraction element.
After reading the above, many possible embodiments of a vascular filter that is convertible into a medical device forming an open lumen, other embodiments, and features will occur to one of ordinary skill in the field. All of these are to be considered as falling within the scope of the attached claims. It is for instance possible to use a vascular filter which has a different shape than the one described above. It is also possible to use a more conventional single vascular filter without the double filter feature. The vascular filter also does not need to comprise ribs extending in an axial direction in relation to the blood vessel.
It should be understood that an unlimited number of configurations for the present invention could be realized. The foregoing discussion describes merely exemplary embodiments illustrating the principles of the present invention, the scope of which is recited in the following claims. Those skilled in the art will readily recognize from the description, claims, and drawings that numerous changes and modifications can be made without departing from the spirit and scope of the invention | A vascular filter for temporary or permanent implantation within a body vessel to filter particulates or thrombus in the blood stream, is capable of being converted some time after initial implantation into a tubular stent. In this configuration, the stent tends to hold the vessel open without any significant filtering effect. The convertible filter/stent may have a tubular metal mesh structure. Also, the device may form one or more filter lattices when in the filter configuration. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention generally relates to articles of furniture and in particular to tables having a novel leg construction.
2. Description of the Related Art
Tables, chairs and other furniture products which are made of wood provide for a warm residential appearance -- even if used as office furniture. Metal tables and chairs can be extremely functional and durable by virtue of the strength characteristics imparted by metal but do not create the warm ambience provided by wood. Wood, on the other hand, does not necessarily provide adequate strength for chairs and tables which can be routinely subjected to extreme wear and tear, especially in the workplace. It has been recognized in the furniture industry that the attributes of wood and metal can be combined into a single article of furniture such as a chair.
For instance, a chair comprising a combination of metal and wooden members is disclosed in U.S. Pat. No. 4,946,224 to Leib, issued Aug. 7, 1990. This patent discloses a chair supported by two wooden side members, each of which forms a front leg, an armrest, a rear leg and a bottom runner. Each front leg has a rectangular metal post mounted therein which is inset from an inside face of the front leg. A wooden panel or plate can be placed over the rectangular metal post to conceal the rectangular post in the wooden front leg.
There have been other attempts in the furniture industry to provide a table or chair leg with a reinforcing member and a decorative cover to conceal the reinforcing member. For example, U.S. Pat. No. 3,846,211 to Begin et al., issued Nov. 5, 1974, discloses a wooden table or chair leg having a shallow longitudinal recess for receiving a reinforcing member which comprises a bundle of glass fibers bound with resin. Begin et al. disclose that a facing of ornamental configuration can be molded directly onto the furniture leg in order to conceal the reinforcing member. It would be preferable if the reinforcing member were made of metal to provide for a stronger construction, and if an ornamental facing would not have to be molded over the reinforcing member to conceal the reinforcing member.
SUMMARY OF THE INVENTION
The invention relates to an article of furniture, such as a table, having a leg construction for supporting the weight of an upper member in the article of furniture wherein the leg construction comprises an elongated metal support member adapted to be secured to the upper member and of sufficient length to support the upper member above the floor. The improved leg construction comprises the metal support member having at least one elongated retaining tongue extending along at least a portion of the length of the metal support member.
An elongated decorative cover member is mounted on the metal support member, the elongated cover member having a length substantially coextensive with the metal support member for covering the metal support member. In addition, the cover member has at least one elongated retaining groove for slidably receiving the elongated retaining tongue of the metal support member and thereby slidably retaining the cover member on the metal support member. The cover member substantially conceals the metal support member from view from at least one side of the furniture article.
The cover member is preferably made of wood. The metal support member preferably comprises two elongated retaining tongues while the cover member preferably comprises two elongated retaining grooves. The metal support member preferably includes two elongated plates, each having a first elongated edge. The elongated plates can be mounted to each other along the first elongated edges such that the elongated plates are disposed at right angles to each other. With this construction, the metal support member has an L-shaped cross section.
Each of the elongated plates can also include a second elongated edge opposite from the first elongated edge. The elongated retaining tongues are preferably integral with the respective second elongated edges.
The invention also relates to the cover member further comprising a concave outside surface, a block portion and two opposing leg portions, each of the opposing leg portions cooperating with the block portion to form the two elongated retaining grooves.
The metal support member can include at least one aperture adapted to receive a fastener, the fastener extending through the metal support member and bearing against the cover member for fixedly mounting the cover member to the metal support member. In addition, the leg construction can include a metal plate secured to an upper portion of the metal support member. The metal plate can be securely mounted to a bottom surface of the upper member of the article of furniture. Further, one or more metal gussets can be secured to an undersurface of the metal plate and to the metal support member in such a manner that sufficient space is provided for a valance to extend to and abut the metal support member.
The invention also relates to a means attached to the metal support member for raising and lowering the metal support member with respect to the floor. Further, the invention is particularly useful if three or more of the improved leg constructions are utilized to support the top of a table above the floor.
The improved furniture leg construction of the present invention is strong and durable, yet retains a substantially wooden appearance. Further, the leg construction is easily assembled or constructed, and the strengthening properties of the metal support member are effectively utilized. In the combination wood-metal leg construction of the invention, the metal support member serves as the primary support element and the cover member serves a primarily decorative function.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described with reference to the drawings in which:
FIG. 1 is a perspective view of a table embodying a novel table leg construction according to the invention;
FIG. 2 is enlarged view of the table leg construction shown in FIG. 1, the view being taken from outside the boundaries of the table and looking toward the table leg construction;
FIG. 3 is a view which is similar to FIG. 2 but wherein the view is taken from inside the boundaries of the table and underneath a horizontal work surface of the table, and looking toward the table leg construction;
FIG. 4 is similar to FIG. 2 but is shown as an exploded view; and
FIG. 5 is a sectional view taken along the lines 5--5 of FIG. 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, and in particular to FIGS. 1-3, a table 10 has a horizontal support 12 which is typically used as a work surface. The horizontal support 12 includes a top surface 14 and a bottom surface 16, the bottom surface 16 having a novel table leg construction 18 attached thereto and extending downwardly toward the floor or ground.
Referring to FIGS. 4 and 5, the table leg construction 18 includes an L-shaped metal leg 20 formed of two elongated plates 22, 24 which are integral and disposed at right angles to each other to thereby form a corner of the L-shaped metal leg 20. The corner has an inside surface 26 and an outside surface 28. Incidentally, it is to be understood that the terms "inside" and "outside" are defined as follows: if a vertical line is drawn through the geometric center of the horizontal support 12, an "inside" object is defined as an object which is relatively closer to this line than an "outside" object which is defined as an object which is relatively further from this line. Thus, as shown in FIG. 5, the inside corner surface 26 is closer to this imaginary vertical line than the outside corner surface 28.
As best seen in FIG. 5, each elongated plate 22, 24 of the L-shaped metal leg 20 includes a tongue 30, 32, respectively, which extends the length of the respective elongated plate 22, 24. These tongues 30, 32 are disposed at right angles to the respective elongated plates 22, 24. If the tongues 30, 32 extended further in their respective horizontal directions, the plates 22, 24 and the tongues 30, 32 would eventually form a cross-section in the nature of a square.
Referring to FIG. 4, an upper end of the L-shaped metal leg 20 is adapted to be received in a square cut-out portion 34 of a generally square metal plate 36. Preferably, the edges of the square metal plate 36 which define the square cut-out portion 34 are welded to the upper end of the L-shaped metal leg 20. As shown in FIGS. 3 and 4, the square metal plate 36 includes a top surface 38 and a bottom surface 40.
As shown in FIG. 3, a metal gusset 42 is formed in the nature of a right triangle and comprises a first side 46, a second side 48 and a hypotenuse 50. Similarly, a metal gusset 44 can be provided, the gusset 44 having a first side 52, a second side 54 and a hypotenuse 56. The first sides 46, 52 of the respective gussets 42, 44 can be secured to the bottom surface 40 of the square metal plate 36 by weldments 58. The second sides 48, 54 of the gussets 42, 44, respectively, can be mounted flush against the respective elongated plates 22, 24 by weldments 60. The metal gussets 42, 44 are preferably mounted to the square metal plate 36 and the elongated plates 22, 24, respectively, in such a manner that sufficient space or room is provided for a side valance 110 or an end valance 112, respectively, to extend to and abut the elongated plates 22, 24, respectively. The metal gussets 42, 44 provide additional strength and flexibility to the table leg construction 18.
Referring to FIG. 4, a glide support 62 can be mounted to the L-shaped metal leg 20 by welding the glide support 62 to the elongated plates 22, 24 at their lower portions at a position adjacent to the outside corner surface 28 of the L-shaped metal leg 20. The glide support 62 is provided with a threaded aperture 64 which is adapted to receive a glide 66. The glide 66 comprises a knob 68 mounted to a threaded shaft 70. The threaded shaft 70 of the glide 66 can be threadably received within the threaded aperture 64 of the glide support 62. By rotating the knob 68 of the glide 66, a bottom surface 69 of the knob 68 can be moved either upwardly or downwardly with respect to the glide support 62 and the floor or ground.
Referring to FIGS. 4 and 5, a wooden leg 72 is provided, the wooden leg 72 having a concave outside surface 74 and a leg portion 76 disposed near one end of the concave outside surface 74 and extending therefrom. Similarly, a leg portion 78 is disposed adjacent the opposing end of the concave outside surface 74 and extends therefrom. The wooden leg 72 includes a block portion 80 which is integral with the leg portions 76, 78. An exterior surface of the block portion 80 defines the concave outside surface 74 of the wooden leg 72. The block portion 80 includes a first surface 82 and a second surface 84 located in right angle relationship. The wooden leg 72 is formed with a longitudinal grove or channel 86 which separates the first surface 82 from the leg portion 76. Similarly, a longitudinal grove or channel 88 separates the second surface 84 from the leg portion 78.
As shown in FIG. 5, the longitudinal groves 86, 88 of the wooden leg 72 are adapted to slidably receive the tongues 30, 32, respectively, of the L-shaped metal leg 20. When the tongues 30, 32 of the L-shaped metal leg 20 are slidably received within the longitudinal groves 86, 88 of the wooden leg 72, the first surface 82 and the second surface 84 of the wooden leg 72 are preferably located in a parallel relationship with the elongated plates 22, 24, respectively.
Referring to FIG. 4, a glide cover 90 can be provided, the glide cover 90 having a configuration similar to the configuration of the wooden leg 72, but having a much shorter length. The glide cover 90 can be made of wood or any suitable material but is preferably formed of a thermoplastic material. If a thermoplastic material is used, the glide cover 90 can be injection molded or preferably extruded in a separate manufacturing operation. The glide cover 90 includes a concave outside surface 92 and a concave inside surface 94, the surfaces cooperating to form two opposing leg portions 96, 98. Extending inwardly from the concave inside surface 94 at respective positions which are near but spaced from the leg portions 96, 98, respectively, are thumb portions 100, 102, respectively. A longitudinal groove or channel 104 is thereby formed in the space between the thumb portion 100 and the leg portion 96, and a longitudinal groove or channel 106 is formed between the thumb portion 102 and the leg portion 98. Thus, the tongues 30, 32 of the L-shaped metal leg 20 can be slidably received within the longitudinal grooves 104, 106, respectively, of the glide cover 90.
Referring to FIG. 4, the table 10 is preferably provided with the side valance 110 and the end valance 112. The side valance 110 comprises an elongated block 114 having a top surface 116 and a strip 118 affixed to a central longitudinal portion of the top surface 116 of the side valance 110. Because of this construction, an end surface 120 of the side valance 110 can be disposed in flush relationship with the elongated plate 22 while the top surface 116 of the side valance 110 can be disposed flush with the bottom surface 40 of the square metal plate 36, as shown in FIGS. 3 and 4.
Similarly, the end valance 112 comprises an elongated block 124 including a top surface 126 having a strip 128 attached thereto. The end valance 112 includes an end surface 130 which is adapted to be disposed in flush relationship with the elongated plate 24 of the L-shaped metal leg 20 after the L-shaped metal leg 20 is mounted to the horizontal support 12. The top surface 126 of the end valance 112 can be disposed flush with the bottom surface 40 of the square metal plate 36, as shown in FIG. 3. As shown in FIG. 3, the side valance 110 and the end valance 112 can be secured to the bottom surface 16 of the horizontal support 12 by fasteners 132.
The table leg construction 18 can be easily assembled. First, as shown in FIG. 4, the glide support 62 is welded to a lower portion of the L-shaped metal leg 20. Next, the edges of the square cut-out portion of the generally square metal plate 36 are welded to the upper ends of the elongated plates 22, 24 of the L-shaped metal leg 20. The metal gussets 42, 44 are then welded to the square metal plate 36 and the L-shaped metal leg 20 as previously described. A welded metal assembly comprising the L-shaped metal leg 20, the square metal plate 36, the metal gussets 42, 44, and the glide support 62 is thereby formed. Preferably, this welded metal assembly is then painted.
Before proceeding with any further assembly steps, the wooden leg 72, the valances 110, 112, and the horizontal support 12 are preferably subjected to a suitable finishing operation. The bottom ends of the longitudinal grooves 86, 88 of the wooden leg 72 are then aligned with and slid over the top ends of the tongues 30, 32, respectively, of the L-shaped metal leg 20. In other words, starting at the top of the L-shaped metal leg 20, the wooden leg 72 is slid downwardly over the L-shaped metal leg 20 until the wooden leg 72 contacts the glide support 62.
Each elongated plate 22, 24 of the L-shaped metal leg 20 preferably includes a countersunk hole 134 adapted to receive a fastener 136. The fasteners 136 can be inserted through the countersunk holes 134 of the L-shaped metal leg 20 so that they bear against the surfaces 82, 84 of the wooden leg 72. Alternatively, the fasteners 136 can be threaded into the surfaces 82, 84 of the wooden leg 72. The fasteners 136 are used to fixedly mount the wooden leg 72 to the L-shaped metal leg 20.
Next, the glide cover 90 is slid over the lower portion of the L-shaped metal leg 20. Preferably, the fit between the L-shaped metal leg 20 and the glide cover 90 is a press fit relationship. The wooden leg 72 and the glide cover 90 together form a cover member which substantially fully conceals the L-shaped metal leg 20 when the table leg construction 18 is viewed from an outside position such as in FIG. 2.
The glide 66 can then be threaded into the glide support 62. Upon accomplishing these steps, the table leg construction 18 is assembled and ready to be secured to the bottom surface 16 of the table 10. Referring to FIG. 3, fasteners 138 can be used to secure the square metal plate 36 to the bottom surface 16 of the table 10. The side valance 110 and the end valance 112 can then be secured to the bottom surface 16 of the table 10 as previously described.
In light of the above detailed description, it is apparent that the present invention fills many needs of the prior art. The table leg construction 18 is strong and durable because the L-shaped metal leg 20 is entirely responsible for supporting the weight of the table 10, yet the table leg construction 18 retains a substantially wooden appearance. The table leg construction 18 is stronger than prior art leg constructions because the L-shaped metal leg 20 serves as the primary supporting or reinforcing element and the wooden leg 72 serves a primarily decorative function, rather than vice versa. The wooden leg 72 is easily mounted to the L-shaped metal leg 20 because of the tongue and groove connection wherein the tongues 30, 32 of the metal leg 20 are received in the longitudinal grooves 86, 88, respectively, of the wooden leg 72. In addition, this tongue and groove connection provides flexibility to the table leg construction 18 because only a small portion of the wooden leg 72 is rigidly secured to the L-shaped metal leg 20. This connection permits a substantial portion of the wooden leg 72 to flex with respect to the metal leg 20. Of particular importance, however, the wooden leg 72 can easily be replaced if ever damaged.
Reasonable variation and modification are possible within the scope of the foregoing specification and drawings without departing from the spirit of the invention. For example, the glide cover 90 can be eliminated and the wooden leg 72 can be made long enough to conceal the entire length of the L-shaped metal leg 20. Further, the leg construction 18 can be used with other articles of furniture such as chairs and the like. Still further, the leg 72 can be made of decorative materials other than wood. For example, the leg 72 can be made of a plastic material. | A leg constuction (18) for supporting the weight of an upper member (12) in an article of furniture (10) comprises an elongated metal support member (20) adapted to be secured to the upper member and of sufficient length to support the upper member above the floor. The metal support member has at least one elongated retaining tongue (30, 32) extending along at least a portion of the length of the metal support member. An elongated wooden cover member (72) is mounted on the metal support member, the elongated cover member having a length substantially coextensive with the metal support member for covering the metal support member. In addition, the cover member has at least one elongated retaining groove (86, 88) for slidably receiving the elongated retaining tongue of the metal support member, thereby slidably retaining the cover member on the metal support member. The cover member substantially conceals the metal support member from view from at least one side of the furniture article. | 0 |
RELATED APPLICATIONS
[0001] This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application No. 60/784,627 filed Mar. 22, 2006 titled “Rotolock Cervical Plate Locking Mechanism,” which provisional application is incorporated herein by reference in its entirety.
FIELD
[0002] The present system and method relate to bone fixation devices. More particularly, the present system and method provide for an orthopedic system including a plate, a screw system, and a complete system including the plate system, the screw system, and the screw retention system.
BACKGROUND
[0003] In the treatment of various spinal conditions, including the treatment of fractures, tumors and degenerative conditions, it is necessary to secure and stabilize the anterior column of the spine following removal of a vertebral body or part. Various devices for internal fixation of bone segments in the human or animal body are known in the art.
[0004] Following such removal made using a thoracotomy, thoracoabdominal or retroperitoneal approach, the normal anatomy is reconstructed using tricortical iliac crest or fibular strut grafts. Not only are removals performed on the thoracic spine, as is the case for the above procedures, but also the cervical spine. Once bone matter is removed, it is then necessary to secure and stabilize the graft, desirably in such a manner as to permit rapid mobilization of the patient. Such objectives can be accomplished by a bone plate. However, to accomplish this service in the optimum manner, it is necessary that the plate be reasonably congruent with the bone to which it is applied, that it have as low a profile as possible, that it be firmly secured to the spinal column so that it is not torn out when the patient places weight and stress upon it and that it be capable of placement and fixation in a manner that is convenient for the surgeon.
[0005] In this context it is necessary to secure the plate to the spinal body and also, in some cases, to the graft. Conventionally, such attachment would be by the use of screws driven through screw holes in the plate into the bone. However, when stabilizing the position of cervical vertebrae, the plate is designed to lie near and posterior to the esophagus of the patient. Due to its relative location to the esophagus and other connective tissue, if the screw securing the plate to the cervical spine backs out, the screw could irritate or even pierce the esophagus, resulting in pain, infection, and/or possible death of the patient. Consequently, anti-back out mechanisms are desired in the orthopedic plate industry.
SUMMARY
[0006] According to one exemplary embodiment, an orthopedic bone fixation device for stabilizing a plurality of bone segments includes a bone plate and a screw assembly. The bone plate includes a body defining at least one thru-bore, wherein the thru-bore is defined to include a central cavity, the central cavity includes a split ring, a compliant member, or another positionable element configured to modify an exit diameter of the thru-bore. Additionally, an actuation member is coupled to the bone plate. According to one exemplary embodiment, actuation of the actuation member, either by rotation, sliding, or the like, causes the actuation member to engage the positionable member, thereby modifying the exit diameter of the thru-bore. Further, the screw assembly is configured to be coupled to the bone plate, wherein the screw assembly includes a bone screw having a head section and a thread section. When actuated, the positionable element is configured to reduce the exit diameter of the thru-bore sufficient to interfere with the head section of the bone screw, thereby preventing the screw from backing out.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The accompanying drawings illustrate various exemplary embodiments of the present system and method and are a part of the specification. Together with the following description, the drawings demonstrate and explain the principles of the present system and method. The illustrated embodiments are examples of the present system and method and do not limit the scope thereof.
[0008] FIG. 1 is a side view of an assembled cervical plate system, according to one exemplary embodiment.
[0009] FIG. 2 is an exploded view illustrating the components of the screw assembly and bone plate of the exemplary embodiment illustrated in FIG. 1 .
[0010] FIG. 3 is a top view of a traditional bone plate, according to various exemplary embodiments.
[0011] FIG. 4A through 4F are various views of a rotationally locked cervical plate system and its individual components, according to one exemplary embodiment.
[0012] FIGS. 5A through 5D are various views of a rotationally locked cervical plate system and its individual components, according to an alternative exemplary embodiment
[0013] FIG. 6 is a flow chart illustrating a method of securing an orthopedic plate, according to one exemplary embodiment.
[0014] FIGS. 7A and 7B are a top and a cross-sectional view of a rotationally locked cervical plate design in an un-locked position, according to one exemplary embodiment.
[0015] FIGS. 7C and 7D are a top and a cross-sectional view of a rotationally locked cervical plate design in a locked position, according to one exemplary embodiment.
[0016] In the drawings, identical reference numbers identify similar elements or acts. The sizes and relative positions of elements in the drawings are not necessarily drawn to scale. For example, the shapes of various elements and angles are not drawn to scale, and some of these elements are arbitrarily enlarged and positioned to improve drawing legibility. Further, the particular shapes of the elements as drawn, are not intended to convey any information regarding the actual shape of the particular elements, and have been solely selected for ease of recognition in the drawings. Throughout the drawings, identical reference numbers designate similar but not necessarily identical elements.
DETAILED DESCRIPTION
[0017] The present specification describes a system and a method for coupling an orthopedic plate to one or more bones while preventing back-out of the fastener. Further, according to one exemplary embodiment, the present specification describes the structure of an orthopedic plate system that selectively constricts the diameter of a thru-bore in the orthopedic plate, thereby preventing back-out of a screw while positionally fixing bone segments. Further details of the present exemplary system and method will be provided below.
[0018] By way of example, orthopedic plate systems may be used in the treatment of various spinal conditions. As mentioned, when applied to stabilize the position of cervical vertebrae, the plate portion of the orthopedic plate system is designed to lie near and posterior to the esophagus of the patient. Due to its relative location to the esophagus and other connective tissue, the top surface of the plate portion may be smooth and free of sharp corners to prevent irritation or piercing of the esophagus and surrounding tissue. Further, in order to prevent irritation and/or piercing, any connection hardware that is used to couple the plate portion to the cervical vertebrae should remain below or even with the top surface of the plate portion.
[0019] If the screw or other fastener securing the plate portion to the cervical spine backs out or otherwise protrudes above the top surface of the plate portion, the screw could irritate or even pierce the esophagus, resulting in pain, infection, and/or possible death of the patient. Consequently, the present exemplary system and method provide an orthopedic plate system including a bone plate with thru-bores. According to the exemplary embodiments disclosed below, the exit diameter of the thru-bores may be selectively modified to secure one or more bone screws with in the thru-bores, thereby preventing the bone screws from backing out.
[0020] Moreover, the present exemplary system and method provides anti-back out protection via an integral or immediately coupled component of the bone plate. Consequently, head height of the bone screw may remain unchanged.
[0021] In the following description, certain specific details are set forth in order to provide a thorough understanding of various embodiments of the present orthopedic plate system and method. However, one skilled in the relevant art will recognize that the present exemplary system and method may be practiced without one or more of these specific details, or with other methods, components, materials, etc. In other instances, well-known structures associated with orthopedic plate systems have not been shown or described in detail to avoid unnecessarily obscuring descriptions of the present exemplary embodiments.
[0022] Unless the context dictates otherwise, throughout the specification and claims which follow, the word “comprise” and variations thereof, such as, “comprises” and “comprising” are to be construed in an open, inclusive sense, that is as “including, but not limited to.”
[0023] The term “compliant mechanisms” relates to a family of devices in which integrally formed flexural members provide motion through deflection. Such flexural members may therefore be used to replace conventional multi-part elements such as pin joints. Compliant mechanisms provide several benefits, including backlash-free, wear-free, and friction-free operation. Moreover, compliant mechanisms significantly reduce manufacturing time and cost. Compliant mechanisms can replace many conventional devices to improve functional characteristics and decrease manufacturing costs. Assembly may, in some cases, be obviated entirely because compliant structures often consist of a single piece of material.
[0024] Reference in the specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. The appearance of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.
Exemplary Structure
[0025] FIG. 1 illustrates a traditional assembled cervical plate system ( 100 ), according to one exemplary embodiment. As illustrated, the traditional cervical plate system ( 100 ) includes a number of components including, but in no way limited to, a bone plate ( 110 ) and at least one screw ( 120 ) coupled to the bone plate ( 110 ). According to the exemplary embodiment illustrated in FIG. 1 , the screws ( 120 ) are configured to be securely coupled to a patient's bone(s) while securely coupling to the bone plate ( 110 ) to provide structural and positional stability while preventing issues with the screw assembly backing out. Further, as illustrated in FIG. 1 , the exemplary cervical plate system ( 100 ), when assembled, maintains the highest point of the screw ( 120 ) below the highest surface of the bone plate ( 110 ).
[0026] FIG. 2 is an exploded view of the traditional cervical plate system ( 100 ). The screw assembly ( 120 ) is selectively inserted into the thru bore(s) ( 230 ) formed in the exemplary bone plate ( 110 ). As mentioned, when fully engaged, the traditional cervical plate system ( 100 ) is able to maintain a relatively low profile while providing structural support. However, there is little or no structure for preventing screw back out. That is, the thru bore(s) merely receive and house the head portion of the screw assembly ( 120 ) and provide little or no resistance to the screw backing out.
[0027] FIG. 3 illustrates a traditional bone plate ( 110 ), according to one exemplary embodiment. As shown, the bone plate generally includes a main plate body ( 300 ) having a number of material cut-out(s) ( 310 ) and thru-bore(s) ( 230 ) formed therein. The plate body ( 300 ) of the bone plate ( 110 ) may be slightly curved to follow the shape of a spinal column and may be formed out of any number of biocompatible metals including, but in no way limited to, stainless steel, titanium, or a titanium alloy. Moreover, the construction of the plate body ( 300 ) may be made of non-metal materials including, but in no way limited to, carbon reinforced Polyetheretherketone (PEEK), and the like. Additionally, as illustrated in FIGS. 3A and 3B , the plate body ( 300 ) has a beveled rounded periphery to eliminate any sharp or abrupt edges that could potentially be damaging to surrounding tissue.
[0028] The material cut-out(s) ( 310 ) formed in the plate body ( 300 ) may serve a number of purposes. According to one exemplary embodiment, the material cut-out(s) ( 310 ) may be designed to eliminate superfluous material, thereby reducing the overall weight of the bone plate ( 110 ), while maintaining the desired structural integrity. Additionally, the various material cut-out(s) ( 310 ) may be configured to facilitate handling of the bone plate ( 110 ) during installation or removal with a tool such as, but in no way limited to, forceps. Further, the material cut-out(s) ( 310 ) may also provide functional access to tissue and/or bone located behind an installed bone plate ( 110 ) without necessitating removal of the plate.
[0029] However, as illustrated in FIG. 3 , the traditional bone plate ( 110 ) is void of any significant back out prevention feature, independent of the screw structure. Consequently, specialized screw assemblies such as those disclosed herein can be used in conjunction with the traditional bone plate ( 110 ) to prevent screw back out.
[0030] In contrast to the traditional cervical bone plate, FIG. 4 illustrates a portion of a rotationally locking cervical plate system ( 400 ), according to one exemplary embodiment. As illustrated in FIG. 4 , the present exemplary rotationally locking cervical plate system ( 400 ) includes a cervical plate ( 110 ) including a number of thru-bores ( 430 ) for receiving an orthopedic fastener. Additionally, as shown, the present exemplary system ( 400 ) includes a cammed actuator ( 420 ) configured to be disposed in the cervical plate ( 110 ) adjacent to the thru bore ( 430 ). Moreover, the present system includes a compressible retention member ( 410 ) configured to selectively vary the exit diameter of the thru-bore ( 430 ) based on an actuation position of the cammed actuator ( 420 ). Furthermore, as is present in traditional cervical plate systems, an orthopedic fastener ( 220 ) is included to secure the present plate ( 110 ) to a desired site. Further details of the present exemplary rotationally locking cervical plate system ( 400 ) will be provided below with reference to FIGS. 4B through 4E .
[0031] An exemplary orthopedic fastener ( 220 ) that may be used with the present rotationally locking cervical plate system ( 400 ) is illustrated in FIG. 4B . While a traditional bone screw ( 220 ) is illustrated in FIG. 4B , and is used for simple explanation herein, the present rotationally locking cervical plate system ( 400 ) may be used with any number of orthopedic fasteners having a protruding member, such as a head. Particularly, as illustrated in FIG. 4B , an exemplary bone screw is shown. As shown, the exemplary bone screw ( 220 ) includes a head portion ( 445 ) and a threaded portion ( 440 ). As is known in the art, the threaded portion ( 440 ) may include, but is in no way limited to a self-tapping thread configured to remove bone and other material as it is driven into a desired site. Additionally, according to one exemplary embodiment, the head portion ( 445 ) of the bone screw or other orthopedic fastener may assume any number of shapes including, but in no way limited to, a circular shape, an oval shape, a quadrilateral based shape, or the like. Additionally, as illustrated in FIG. 4B , the orthopedic fastener ( 220 ) may include any number of driving features ( 450 ) configured to aid in driving the orthopedic fastener into a desired site. For example, according to one exemplary embodiment, the driving feature of the orthopedic fastener ( 220 ) may include, but is in no way limited to, a hex-head, a Phillips head, a flat head, and the like.
[0032] FIG. 4C illustrates the features of the present exemplary cammed actuator ( 420 ), according to one exemplary embodiment. As shown, the cammed actuator ( 420 ) includes a main body having a number of lobes. Particularly, as illustrated in FIG. 4C , the cammed actuator is a heart-shaped actuator including a plurality of raised engagement lobes ( 454 ) on an upper half of the cammed actuator ( 420 ), and a plurality of recessed converging surfaces or lobes ( 456 ) on a lower half of the actuator ( 420 ). Additionally, according to the illustrated exemplary embodiment, an actuating orifice ( 460 ), such as a slit or other profile configured to receive an instrument, is defined in the upper surface of the actuator ( 420 ). Furthermore, a pivot element ( 462 ) is projecting from the bottom of the cammed actuator ( 420 ) and can include a coupling element ( 464 ) for coupling the actuator to the bone plate ( 110 ). According to one exemplary embodiment, the coupling element ( 464 ) is configured to receive a backing element (not shown) or some other positioning element configured to maintain the cammed actuator rotatably coupled to the bone plate ( 110 ). The presently illustrated cammed actuator allows for a single actuator to lock or disengage two orthopedic fasteners simultaneously. While the present exemplary embodiment is illustrated as including a cammed actuator ( 420 ) configured to simultaneously couple two orthopedic fasteners, any number of lobes and recesses may be formed to couple various numbers of fasteners.
[0033] As illustrated in the exemplary embodiment of FIG. 4A , the cammed actuator ( 420 ) is rotatable coupled to the bone plate ( 110 ) interposed between a plurality of thru-bores ( 430 ). According to one exemplary embodiment, the cammed actuator ( 420 ) is configured to have two main positions: locked and unlocked. When the cammed actuator is in the unlocked position, according to one exemplary embodiment, the two raised engagement lobes ( 454 ) are not forced upon the periphery of the compressible retention members ( 410 ). However, when in the locked position, the cammed actuator ( 420 ) is rotated approximately 180 degrees, according to one exemplary embodiment, and the two raised engagement lobes ( 454 ) are actuated against the compressible retention members ( 410 ).
[0034] FIGS. 4D and 4E illustrate a perspective view and a cross-sectional view of a compressible retention member ( 410 ), according to one exemplary embodiment. As illustrated, the retention member ( 410 ) may be a split-ring ( 410 ). As illustrated, the split ring ( 410 ) includes a main ring body ( 468 ) having a generally circular profile. Additionally, as shown, the split ring ( 410 ) can include an externally protruding annular retention flange. As will be described below, the annular retention flange ( 470 ) may correspond to any number of features present in a thru-bore ( 430 ) of the bone plate ( 110 ) to be used to maintain the split ring ( 410 ) within the bone plate ( 110 ). Additionally, according to one exemplary embodiment, the ring body ( 468 ) includes a back-out projection ( 476 ) that projects inward towards the center of the split ring ( 410 ) and may be selectively imposed into the pathway of an orthopedic fastener ( 220 ) to prevent the fastener ( 220 ) from backing out from the plate ( 110 ). Furthermore, the split ring ( 410 ) includes a split ( 472 ) allowing for the selective compression of the split ring by the cammed actuator ( 420 ; FIG. 4C ), as will be described in detail below. According to one exemplary embodiment, the split ring ( 410 ) also defines a thru-bore ( 474 ) that, according to one exemplary embodiment, has a diameter greater than the diameter of the head portion ( 445 ) of the orthopedic fastener ( 220 ) when the split ring ( 410 ) is in its relaxed state. However, when acted upon by a cammed actuator ( 420 ; FIG. 4C ), the diameter of the split ring ( 410 ) disposed in the opening of the plate thru-bore ( 430 ) is less than the diameter of the head portion ( 445 ) of the orthopedic fastener ( 220 ).
[0035] FIG. 4E illustrates the present exemplary bone plate ( 110 ), according to one exemplary embodiment. As illustrated, the bone plate ( 110 ) includes a number of thru-bores ( 430 ) joined by a cam recess ( 436 ). According to one exemplary embodiment, the cam recess ( 436 ) includes a cam retention port ( 438 ) configured to receive the pivot element ( 462 ; FIG. 4C ) of the cammed actuator ( 420 ; FIG. 4C ). Additionally, the internal wall of the thru-bores ( 430 ) contain a number of features. Particularly, the thru-bore ( 430 ) can include a ring retention undercut ( 434 ) configured to receive and mate with the annular retention flange ( 470 ; FIG. 4D ) of the split ring ( 410 ; FIG. 4D ), thereby coupling the split ring to the thru-bore. According to one exemplary embodiment, the split-ring ( 410 ) may be initially compressed and then inserted into the ring retention undercut ( 434 ). Furthermore, the bottom or exit diameter of the thru-bore ( 430 ) is less than the entrance diameter, thereby allowing for the passage of the bone screw ( 220 ) through the entrance diameter, but seating the head of the bone screw ( 220 ) on a screw seat ( 432 ). According to one exemplary embodiment, when the present exemplary system is assembled, a bone screw ( 110 ) may be introduced into the thru-bore ( 430 ) of the screw plate ( 110 ), past the relaxed compressible member ( 410 ) and into the screw head seat ( 432 ). The cammed actuator ( 420 ) may then be actuated to compress the compressible member ( 410 ) and introduce the back-out projection over the inserted screw head, thereby preventing the screw from backing out.
[0036] FIGS. 5A-5D illustrate an alternative configuration of the rotationally locking cervical plate system using another type of compressible member ( 410 ). As illustrated in FIG. 5A , an exemplary system can include a plate ( 110 ′) having a plurality of thru bores ( 430 ), as mentioned above. Additionally, the alternative configuration may use any number of orthopedic fasteners ( 220 ), as mentioned previously. However, in contrast to the previously illustrated rotationally locking cervical plate system, the present exemplary system ( 110 ′) includes a larger dual-cammed actuator ( 520 ) and a cantilevered compressible back-out member ( 570 ).
[0037] As shown in FIG. 5B , the dual-cammed actuator ( 520 ) includes substantially the same components as the previously mentioned cammed actuator ( 420 ). That is, the dual-cammed actuator ( 520 ) is a heart-shaped actuator including a plurality of raised engagement lobes ( 554 ) on an upper half of the cammed actuator ( 520 ), and a plurality of recessed converging surfaces or lobes ( 556 ) on a lower half of the actuator ( 520 ). Additionally, according to the illustrated exemplary embodiment, an actuating orifice ( 560 ), such as a slit or other profile configured to receive an instrument, is defined in the upper surface of the actuator ( 520 ). Furthermore, a pivot element ( 562 ) is disposed between the cammed surfaces.
[0038] However, in contrast to the exemplary system illustrated in FIG. 4A , the present exemplary rotationally locking cervical plate system ( 500 ) includes cantilevered back-out members ( 570 ) in place of the previously used compressible split ring ( 410 ). According to the exemplary embodiment illustrated in FIGS. 5C and 5D , the cantilevered back-out members ( 570 ) are compliant and compressible members configured to perform the same operation as the split ring ( 410 ). That is, the cantilevered back-out members ( 570 ) include a back-out projection ( 576 ) extending towards the thru-bore ( 530 ). When a desired orthopedic fastener ( 220 ) is received, the cantilevered back-out member may receive a force transferred from the actuator ( 520 ) such that the back-out projection ( 576 ) interferes with the head portion of the orthopedic fastener ( 220 ) when disposed in the screw seat ( 578 ). An exemplary method of operation of the rotational lock cervical plate will be provided below with reference to FIGS. 6 through 8D .
Exemplary Method
[0039] FIG. 6 illustrates a method for installing the exemplary cervical plate system including a rotational locking mechanism, according to one exemplary embodiment. As illustrated in FIG. 6 , the present exemplary method for installing the cervical plate system includes placing the bone plate adjacent to one or more desired vertebral bones (step 7600 ). Once the bone plate is appropriately positioned, the screw assembly may then be presented to a thru-bore of the bone plate with the positionable element in a large diameter position (step 610 ). The screw assembly is then driven through the thru-bore in the bone plate into the desired vertebral bone (step 620 ) until the enlarged head of the screw assembly is within the central cavity of the thru-bore (step 630 ). Once the screw assembly is correctly positioned, the cammed actuator may be engaged to compress the compressible element and reduce the exit diameter of the thru bore, thereby capturing the screw assembly within the thru-bore (step 740 ). Further details of each step of the present exemplary method will be provided below with reference to FIGS. 8A through 8D .
[0040] As illustrated in FIG. 7 , the first step of the exemplary method is to place the plate adjacent to a desired vertebral bone (step 700 ). The placement of the bone plate relative to a vertebral bone in a patient may be pre-operatively determined based on a pre-operative examination of the patient's spinal system using non-invasive imaging techniques known in the art, such as x-ray imaging, magnetic resonance imaging (MRI), and/or fluoroscopy imaging, for example. Any additional preparation or work may be done on and around the desired vertebral bone prior to positionally orienting the bone plate.
[0041] With the bone plate appropriately positioned relative to a desired vertebral bone (step 700 ), the screw assembly may be presented to a thru-bore of the bone plate with the positionable element in a large diameter position (step 710 ). As shown in FIGS. 8A and 8B , the screw assembly may be delivered to the bone plate with the lock knob un-actuated, causing the positionable element to maximize the entry diameter of the thru-bore. Consequently, the screw assembly may be entered into the thru-bore without obstruction.
[0042] When presented, the screw assembly may then be driven through the thru-bore in the bone plate into a desired vertebral bone (step 720 ), as illustrated in FIGS. 8A and 8B . As illustrated in FIGS. 8A an 8 B, the desired orthopedic fasteners ( 220 ) are driven through the thru-bore ( 430 ) while the cammed actuator ( 420 ) is in an unlocked position. In other words, the engagement lobes ( 454 ) are rotated away from the compressible retention member(s) ( 410 ) and the recessed surfaces ( 456 ) are in contact with the compressible retention members. Consequently, there is no interference for the head portion ( 445 ) of the orthopedic fastener ( 220 ) to pass there through. FIG. 8B also illustrates the annular retention flange ( 470 ) being maintained by the ring retention undercut ( 434 ).
[0043] Once the screw assembly is correctly positioned in the thru-bore ( 430 ), the compressible member ( 410 ) is engaged by the cammed activator ( 420 ) to reduce the exit diameter of the thru-bore ( 430 ), thereby capturing the orthopedic fastener within the thru-bore (step 740 ), as illustrated in FIGS. 8C and 8D , the back-out projection ( 476 ) impedes the removal of the orthopedic fastener ( 220 ). According to one exemplary embodiment, the cammed activator ( 420 ) is rotated approximately 180 degrees, causing the back out projection ( 476 , 576 ) of the compressible member to be forced in over the orthopedic fastener. According to one exemplary embodiment, there can be a swept cutout in the cantilevered back-out member ( 570 ) or the compressible member ( 410 ) which mates with the head portion ( 445 ) of the orthopedic fastener ( 220 ).
[0044] While the present exemplary rotationally locking cervical plate system has been described, for ease of explanation only, in the context of a cervical plate system, the present exemplary systems and methods may be applied to any number of orthopedic fixtures. Specifically, the present screw back out prevention components may be used to couple any number of orthopedic apparatuses to a desired bone, for any number of purposes, as long as the connecting orthopedic apparatus includes a thru-bore substantially conforming with the configurations described herein.
[0045] In conclusion, the present exemplary systems and methods provide for coupling an orthopedic plate to one or more bones while preventing back-out of the fastener.
[0046] The preceding description has been presented only to illustrate and describe the present method and system. It is not intended to be exhaustive or to limit the present system and method to any precise form disclosed. Many modifications and variations are possible in light of the above teaching.
[0047] The foregoing embodiments were chosen and described in order to illustrate principles of the system and method as well as some practical applications. The preceding description enables others skilled in the art to utilize the method and system in various embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the scope of the present exemplary system and method be defined by the following claims. | According to one exemplary embodiment, an orthopedic bone fixation device for stabilizing a plurality of bone segments includes a bone plate and a screw assembly. The bone plate includes a body defining at least one thru-bore, wherein the thru-bore is defined to include a central cavity, the central cavity includes a split ring, a compliant member, or another positionable element configured to modify an exit diameter of the thru-bore. Additionally, an actuation member is coupled to the bone plate. According to one exemplary embodiment, actuation of the actuation member, either by rotation, sliding, or the like, causes the actuation member to engage the positionable member, thereby modifying the exit diameter of the thru-bore. Further, the screw assembly is configured to be coupled to the bone plate, wherein the screw assembly includes a bone screw having a head section and a thread section. When actuated, the positionable element is configured to reduce the exit diameter of the thru-bore sufficient to interfere with the head section of the bone screw, thereby preventing the screw from backing out. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] Not Applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
[0002] Not Applicable.
BACKGROUND OF THE INVENTION
[0003] The present invention relates in general to a handset for cellular wireless telephones, and, more specifically, to a handset adapted to provide features for acting as an input manipulator for video games that can be played on the display of the handset or over the wireless network.
[0004] Guitar simulation video games such as Guitar Hero (published by RedOctane, Inc.) have become popular for game play that includes solo, cooperative, and competitive modes. Games of this type have been introduced for many different game consoles, as well as versions for personal computers and mobile cell phones. Standard game controllers have been used, such as game pads or joysticks, but many players prefer the use of mock guitar controllers specially made for the game platforms having various push buttons corresponding to guitar frets and other manipulators for controlling strumming action and tremolo or vibrato (i.e., a whammy bar). While such guitar controllers are portable in the sense that they can be taken to a friend's house of other gathering place having a game console or platform, they are too large to be conveniently carried in a pocket or purse, for example. Thus, an impromptu formation of a group of people for playing a game (i.e., a spontaneous jam session) is less likely to occur since a user desiring to play may not have a desired controller available.
[0005] Known versions of guitar simulations playable on a mobile cellular phone have not supported multi-players and have been limited to user input based on selected push buttons (i.e., keys) on the cellular phone. Furthermore, the phone display has been used as the game display so that natural and easy interaction with the game is reduced. Since no remote connectivity or network play has been supported, the normal performance expected by users of the console games has been lacking.
SUMMARY OF THE INVENTION
[0006] The present invention provides a mobile phone handset incorporating a guitar-type game manipulator that allows the player to use natural strumming and fretting techniques without reducing the utility of the phone for use as a cellular telephone. It provides a game manipulator with network connectivity for use in multi-player games employing a game server which further connects to a large display or monitor associated with a conventional game platform.
[0007] In one aspect of the invention, a cellular handset is provided for manipulating a video game. A first beam generator projects a first beam from a selected surface of the handset, and a second beam generator projects a second beam from the selected surface. A first detector proximate the selected surface detects a first manual interaction of a user with the first beam, and a second detector proximate the selected surface detects a second manual interaction of a user with the second beam. Command logic coupled to the first and second detectors interprets a first manual interaction preceding a second manual interaction as a downstroke command and interprets a second manual interaction preceding a first manual interaction as an upstroke command. The command logic is adapted to be coupled to a game controller to transmit the downstroke and upstroke commands as input to the video game.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a front, plan view of a handset of the invention having a tailpiece in an extended position.
[0009] FIG. 2 is a rear, perspective view of the handset of FIG. 1 .
[0010] FIG. 3 is a side view of the handset of FIG. 1 .
[0011] FIG. 4 is a perspective view of the handset being used to control a guitar simulation game.
[0012] FIG. 5 is a signal timing diagram for interpreting manual commands via the beam detectors.
[0013] FIGS. 6-9 show an alternative embodiment of the handset for providing repositionable fret buttons for either right-handed or left-handed use.
[0014] FIG. 10 shows an alternative embodiment using two beam generators and one beam detector.
[0015] FIG. 11 is a block diagram showing the handset and video game elements in greater detail.
[0016] FIG. 12 is a block diagram showing a network system for supporting use of the handset in a multi-player gaming environment.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0017] Referring to FIG. 1 , a cellular handset of the present invention includes a main body 11 having an antenna housing 12 , a graphics display 13 , and a conventional keypad 14 . Handset 10 performs all the normal functions of a cellular phone including communication of voice and/or data signals in a wireless cellular system.
[0018] Handset 10 includes additional elements providing it with the capability to act as an ergonomically realistic video game controller for video games utilizing particular combinations of manual movements such as guitar-based games to simulate the playing of a guitar (e.g., pressing fret buttons or making strumming movements according to a particular timing sequence as shown in a game display). Thus, a plurality of fret push buttons 15 - 19 is provided in a substantially straight row along one narrow side of main body 11 . To provide a natural strumming method, a pair of infrared transceivers 20 and 21 (each including a respective infrared transmitter or beam generator and a infrared detector) is disposed on a selected surface 22 of main body 11 . Preferably, surface 22 is the bottom edge of main body 11 as shown. Infrared transceiver 20 generates a first infrared beam 23 projected toward a reflector 24 . Reflector 24 is held at a spaced position from surface 22 in alignment with beam 23 in order to reflect it to the detector in transceiver 20 . Likewise, transceiver 21 generates a second infrared beam 25 projected to receiver 24 for reflection back to the detector in transceiver 21 by reflector 24 . An extension rod 26 deploys from a retention slot in main body 11 to slidably extend outward from surface 22 . Rod 26 has reflector 24 mounted at its distal end to create a strumming area 27 between surface 22 and reflector 24 . A preferred embodiment detects strumming as interruptions in beams 23 and 25 . With properly selected beam characteristics, however, it is also possible to dispense with a reflector and instead detect the reflection of a beam by the hand or other object controlled by the user. In that alternative embodiment, a return of the beam would not normally be detected except when the user makes a control action to move the hand into the beam where it can reflect some of the beam to the detector. In either embodiment, the user moves their fingers or other objects (such as a guitar pick) in strumming area 27 to create a first manual interaction with the first beam which is detected by the first detector, and a second manual interaction with the second beam which is detected by the second detector.
[0019] As described below, two infrared beams are used in order to enable detection of a strumming direction. Thus, when the first manual interaction precedes the second manual interaction, a downstroke strumming command is generated. When the second manual interaction precedes the first manual interaction, it is interpreted as an upstroke strumming command. Beams 23 and 25 may preferably be substantially parallel when leaving transceivers 20 and 21 . In order to minimize interference or crosstalk between the beams, reflector 24 preferably has a non-planar shape causing the reflected beams to slightly diverge. Thus, reflector 24 is shown having a first wing 28 and a second wing 29 wherein the ends of wings 28 and 29 are slightly further from surface 22 than at their central attachment point to extension rod 26 . In other words, reflector 24 is optically convex to diverge the reflected beams.
[0020] Infrared transceivers 20 and 21 may comprise commonly available, low cost devices such as those already used in personal digital assistance (PDA) cellular handsets for performing infrared data transmission (e.g., as an IrDA port). The transceivers typically include an infrared light emitting diode (LED) and an infrared photodetector covered by an infrared-transmitting plastic lens. Alternatively, discrete LED's and photodetectors may be employed. Furthermore, other non-infrared light sources and detectors or other proximity sensing technologies such as ultrasonics can be employed in the present invention.
[0021] As shown in FIG. 2 , main body 11 has a recess 31 for receiving extension rod 26 allowing it to retract so that reflector 24 is stowed in a recess 32 within surface 22 . Preferably, a locking mechanism (not shown) is employed within main body 11 for firmly locking extension rod 26 and reflector 24 in either a retracted or an extended position. For example, a locking system may be activated by rotating reflector 24 by 180° after it is slid to its extended position. Detents or catch mechanisms can alternatively be used to generate the locks. Since extension rod 26 is substantially straight and reflector 24 is elongated in a direction parallel with the side-to-side direction of surface 22 , recess 32 must also extend in the side-to-side direction, but it is offset (i.e., adjacent to) the location of transceivers 20 and 21 .
[0022] Because of a possible offset between the orientation of the transceivers and the positioning of the reflector by the straight rod, the reflector elements on each wing are provided with a particular shape to create a predetermined rotation of beams 23 and 25 towards the infrared transceivers. For example, the flat, reflecting surfaces of the reflector wings are sloped at an angle with respect to elongated rod 26 as shown in FIG. 3 . Thus, the predetermined rotation of the infrared beams is perpendicular to the side-to-side dimension of surface 22 . As a result, the infrared beams are more directly reflected back to the transceivers and the necessary movements of the hand through strumming area 27 is raised away from extension rod 26 so that rod 26 does not interfere with the strumming action.
[0023] In addition to a downstroke and an upstroke command, the present invention can recognize a third command in response to the hand being held in such a way that it blocks both infrared beams simultaneously. The third command can correspond with the vibrato, tremolo, or a whammy bar function (i.e., pitch bending).
[0024] FIG. 4 shows a manner of use of the handset as a guitar controller. Main body 11 is grasped in a hand 35 so that the fingers can easily reach across the front of the handset to fret buttons 15 - 19 . Reflector 24 is extended from recess 32 to create strumming area 27 within which infrared beams 23 and 25 normally circulate. A hand 36 is brought into strumming area 27 to sweep over beams 23 and 25 sequentially in a downward or upward movement. In addition, hand 36 can be placed to simultaneously interrupt beams 23 and 25 for a third command.
[0025] Detection of a strumming command is performed using the preferred method of FIG. 5 . In one preferred embodiment, the infrared generators are always on so that infrared beams 23 and 25 are continuous, thereby providing a substantially continuous received signal at both detectors. Waveforms 40 and 41 represent a logic signal that is generated in response to the detector signals and having a first logic level when a respective beam is unblocked (i.e., being received) and a second logic level when a respective beam is blocked (i.e., not being received). In the example shown, waveforms 40 and 41 have a high logic level during detection of an interruption (i.e., a manual interaction) from the two detectors.
[0026] When a first manual interaction begins wherein the users hand begins to block the first beam, waveform 40 shows a rising leading edge 42 at the corresponding time. As the user's hand moves downward in the strumming area, eventually the first beam is unblocked resulting in a trailing edge 43 in waveform 40 where the interruption detection logic signal is restored to a low logic level. The user's hand continues to move downward and eventually blocks the second beam so that waveform 41 shows a rising leading edge 44 . A delay time t d1 between leading edges 42 and 44 is determined by a logic controller which is coupled to the infrared transceivers. If delay t d1 matches a predetermined delay, then a downstroke strumming command is detected. The predetermined delay has a range of time values according to a maximum speed at which the strumming is to occur. Thus, inadvertent or incorrect blockage of the infrared beams is not interpreted as a strumming stroke. Delays within the predetermined range of times can also be detected and used to indicate different strumming speeds for use in controlling the video game, if desired. On the other hand, the minimum time delay within the range for detecting a strumming command is sufficiently long to accommodate a small error in the user's ability to block both beams simultaneously when intending to generate the third command.
[0027] An upstroke command is generated by moving the hand or fingers in an upward direction through the strumming area to generate first rising edge 45 in waveform 41 and then a second rising edge 46 in waveform 40 , wherein a time delay t d2 between rising edges 45 and 46 is within the predetermined delay range.
[0028] To provide further flexibility in generating fret commands using appropriate push buttons, the fret buttons may be mounted to a pivotally-attached swing arm having a button surface substantially perpendicular to surface 22 as shown in FIGS. 6-9 . Thus, a swing arm 50 is attached to upper and lower ends of main body 11 at pivot points 51 and 52 such that swing arm 50 swings or rotates around main body 11 over a range of at least about 180° between a right-handed playing position shown in FIG. 6 and a left-hand playing position shown in FIG. 9 . Detents or other holding mechanisms may preferably be associated with pivots 51 and/or 52 for maintaining swing arm 50 in its end positions shown in FIGS. 6 and 9 .
[0029] FIG. 7 shows swing arm 50 being rotated between opposite sides. It may be desirable to provide additional holding positions using detents at such an intermediate position to adapt use of the handset controls to a different type of video game, for example. FIG. 8 shows an end view with swing arm 50 in an intermediate position. An aperture 58 is provided through swing arm 50 to be aligned with infrared transceivers 20 and 21 when in its end positions so that swing arm 50 does not interfere with the infrared beams.
[0030] FIG. 10 shows an alternative embodiment employing a pair of beam generators comprising infrared LED's 60 and 61 generating beams 62 and 63 which are projected toward a reflector 64 . Due to a slightly concave shape of reflector 64 , beams 62 and 63 are converged to a single detector 65 . Instead of providing reflector 64 with a non-planar shape to converge the beams, an optically modified surface such as a series of saw tooth-shaped grooves can alternatively be used.
[0031] In order to separately detect interruption of beams 62 and 63 using a single detector 65 , the beams are modulated in different ways in order to enable reception of each beam to be distinguishable. One modulation scheme is to alternately pulse each LED 60 and 61 to alternately produce a detectable signal at detector 65 . Pulsing is required to occur at a period shorter than the time in which significant movement of the hand sweeping through the strumming area could move an appreciable distance compared to the width of the beams.
[0032] Alternatively, each beam can be modulated with an information content that is uniquely recoverable by detector 65 to detect at what times each beam is still being received. For example, each beam can be amplitude modulated or frequency modulated according to unique frequencies or information content that are non-overlapping. Various code transmission protocols could be used as are known in the art.
[0033] A hardware implementation of the present information is shown in greater detail in FIG. 11 . A first LED 70 and a first photodetector 71 are coupled to an interface and driver circuit 72 . Devices 70 - 72 may comprise a commercially available infrared transceiver, for example. Interface and driver circuit 72 operates under control of command logic 73 . In one preferred embodiment, command logic 73 provides an activation signal to driver and interface circuit 72 when the handset is in a mode to detect strumming commands. Interface and driver circuit 72 automatically controls operation of LED 70 and photodetector 71 and provides an interruption signal to command logic 73 when its respective beam is being interrupted. When a single detector is being used, modulation of the beam and demodulation of the detected beam may preferably be performed by interface and driver circuit 72 , but could alternative be handled by command logic block 73 . A second LED 74 and photodetector 75 are connected to another interface and driver circuit 76 similarly connected to command logic 73 . Fret buttons 77 are coupled to command logic 73 through an interface 78 .
[0034] Command logic 73 compares interruption events detected for each respective beam to interpret the occurrence of upstroke and downstroke commands, as well as the third command representing the pitch bending function. Thus, if interruption events occur with rising edges within a predetermined shortest delay time, then a third command is generated. If interruption events occur according to a delay within the predetermined delay range, then an upstroke or downstroke command is generated. The generated commands are provided to a game controller 80 which is coupled to a game display 81 . Game controller 80 implements the actual video game software such as the guitar simulation and may reside either on the handset itself or remotely on a game platform accessed by the handset over the cellular network.
[0035] FIG. 12 shows a network system for supporting multiplayer games accessible to a player using a handset 82 of the present invention. Handset 82 wirelessly connects to a base station 83 in turn coupled to a base station controller (BSC) 84 . The wireless cellular system preferably supports digital data transmission to a packet data serving node (PDSN) 85 which is coupled to an IP network 90 (which may preferably be owned and operated by the wireless service provider). A central game controller 91 is coupled to IP network 90 and implements the video game in response to inputs from the player using handset 82 . A second player using a handset 86 may be similarly coupled to a base station 87 and a BSC 88 in order to send digital data commands to PDSN 85 for forwarding to game controller 91 through IP network 90 . Game controller 91 may be configured to provide video game output to a designated set top box (STB) 92 associated with a television display 93 . Thus, the players using handsets 82 and 86 do not need to view the game using displays on their handsets but can playing the video game from the location of TV monitor 93 to view the game display. Additional players can be joined to a game from a PC or other game console 94 coupled by a gateway 95 to IP network 90 . Alternatively, a PC or console 94 can be utilized by game controller 91 as the game display. | A cellular handset and video game manipulator has first and second beam generators projecting first and second beams from a selected surface of the handset. First and second detectors proximate the selected surface detect first and second manual interactions of a user with the beams. Command logic coupled to the first and second detectors interprets a first manual interaction preceding a second manual interaction as a downstroke command and interprets a second manual interaction preceding a first manual interaction as an upstroke command. The command logic is adapted to be coupled to a game controller to transmit the downstroke and upstroke commands as input to a video game, such as a guitar simulation. The player enjoys natural strumming and fretting techniques without reducing the utility of the phone for use as a cellular telephone. Network connectivity is provided to enable use in multi-player games employing a game server which further connects to a large display or monitor associated with a conventional game platform. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to mechanical presses for processing workpieces such as metals or other materials and more particularly to a method and devices which facilitates safe operation of mechanical presses.
2. Description of the Prior Art
In mechanical presses, a ram holding an upper tool or die is vertically moved in processing operations by means of a crank shaft or eccentric shaft toward and away from a lower tool or die to process workpieces which are placed on the lower die. For manual operations in which workpieces are manually fed onto and removed from the lower die by hand, mechanical presses have to be so designed that the ram may be positively stopped at its uppermost limit of travel after completion of each working cycle or stroke. As is well known, mechanical presses are provided with a clutch and a brake which are often provided as an assembly and are mostly pneumatically operated, and the ram is stopped when the clutch and the brake are simultaneously operated. Of course, the clutch is so designed as to connect and disconnect the crank shaft for driving the ram with the power source such as a flywheel and a motor, while the brake is operated to stop the crank shaft simultaneously when the clutch disconnects the same from the power source.
In mechanical presses, it has been that the ram often fails to stop at its uppermost travelling limit after completing it stroke and will repeat another stroke because of malfunction of the clutch and the brake or electric or pneumatic means for controlling these elements, e.g., a solenoid operated valve, or for any other reasons. Needless to say, there is a danger of injuring the operator of the press if the ram repeats an unintended stroke without stopping at its uppermost travelling limit. Actually, accidents in operations with mechanical presses have happened mostly from such unintentional repeated strokes of the rams.
Although some mechanical presses are doubly equipped with solenoid operated valves for controlling the clutch and the brake for extra safety, of course this arrangement could not prevent the ram from unintentionally repeating its stroke owing to malfunctions other than that of the solenoid operated valve. Also, some presses are so constructed that the crank shaft is mechanically and forcibly stopped by a stop means such as a pin from unintentionally rotating past its upper dead center to stop the ram from double stroking past its uppermost travelling limit. However, this arrangement not only could not positively prevent the ram from double stroking except when the clutch is incompletely connecting the crank shaft with the power source, but also it tends to damage the press and its components because of the shock occuring when the ram is forcibly stopped.
SUMMARY OF THE INVENTION
It is a primary object of the present invention to provide a method in which a ram in mechanical presses can be positively and safely stopped from repeating an unintended stroke past its uppermost travelling limit after a completion of a stroke without causing any damage to the press.
It is another object of the present invention to provide a safety device for mechanical presses which can positively and safely stop the ram from repeating an unintended stroke past its uppermost travelling limit after a completion of a stroke without causing any damage to the press.
Basically, these objects are accomplished by providing a mechanical press with a second clutch means disposed between its main clutch and its ram, and which pneumatically connects the crank shaft with the power source in normal operations and which is operated by a spring or springs to disconnect the same as soon as the crank shaft begins to unintentionally rotate past its upper dead center to allow the ram to repeat an unintended stroke.
In this connection, it is another object of the present invention to provide an auxiliary clutch means for disconnecting the crank shaft with the power source when the main clutch is not positively disengaged at the completion of a stroking cycle.
Other and further objects and advantages of the present invention will be apparent from the following description and accompanying drawings which, by way of illustration, show preferred embodiments of the present invention and the principle thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of a mechanical press embodying the principles of the present invention.
FIG. 2 is a schematic illustration showing an embodiment of the principles of the present invention.
FIG. 3 is a schematic illustration showing the embodiment of FIG. 2 in cross-section along the line III--III of FIG. 2.
FIG. 4 is a fragmentary sectional view of the embodiment shown in FIGS. 2 and 3.
FIG. 5 is a schematic illustration showing another embodiment of the principles of the present invention.
FIG. 6 is a fragmentary sectional view of the embodiment shown in FIG. 5.
FIG. 7 is a sectional view of the embodiment shown in FIGS. 5 and 6 along the line VII--VII of FIG. 6.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, a mechanical press generally designated by the numeral 1 is conventional in that it is constructed of a C-shaped frame 3 and has a worktable 5 on which a lower tool or die (not shown) is mounted. As is also conventional, the press 1 is provided at its front upper portion with a ram 7 which is to be provided at its lower end with an upper tool or die (not shown) and is so mounted as to be vertically moved along a guide means 9 by a crank shaft or eccentric shaft 11 through a connecting rod 13 (FIG. 3). Also, the crank shaft 11 for driving the ram 7 is driven in the conventional manner by a motor 15 through a flywheel 17 and a transmission 19 which is schematically shown in FIGS. 2 and 5 as including a clutch and brake assembly 21 and having an output gear 23. However, the crank shaft 11 according to the present invention is different from conventional ones in that it is so constructed as to be connected with and disconnected from the output gear 23, as will be described hereinafter. Also, of course the clutch and brake assembly 21 and the output gear 23 can be provided in different manners other than those shown in FIGS. 2 and 5. Thus, the ram 7 is vertically lowered by the crank shaft 11 to the worktable 5 to process a workpiece placed thereon when the clutch and brake assembly 21 is operated to transmit the power to the crank shaft 11 in the conventional manner.
As is also conventional, the ram 7 is equipped with counterbalance means 25 for counterbalancing the moving weight of the ram 7 and other members attached thereto. The counterbalance means 25 may be of any type, but they comprise pneumatic cylinders 27 each having a piston 29 and a piston rod 31 fixed thereto in the preferred embodiment. Also, although two counterbalance means 25 are shown in FIGS. 2 and 5, any number of them may be employed depending upon the type and the size of the press 1. The counterbalance means 25 are mounted to stationary portions on the crown or the uprights of the press 1, and their piston rods 31 are attached to the ram 7 so that they may be moved together therewith. In order to counterbalance the moving weight of the ram 7, the counterbalance means 25 are supplied with air into their cylinders 33 from an air source 35 through a conduit 37 which is provided with a reducing valve 39 and a check valve 41. Thus, the ram 7 is counterbalanced by the counterbalance means 25, and it is lowered to the worktable 5 against the air pressure in the chambers 33 of the counterbalance means 25 so as to process the workpiece. As will be understood as the description proceeds, the counterbalance means 25 are most effectively utilized as buffers or shock absorbers to softly stop the ram 7 without shock from unintendedly double stroking according to the present invention.
Referring to FIGS. 2 and 4, the crank shaft 11 is provided at its end adjoining the transmission 19 with a gear 43 which is provided at its inner side with a plurality of radially disposed claws 45. The gear 43 is rotatably mounted on the crank shaft 11 by means of a bearing 47 so as to engage the output gear 23 of the transmission 19. Also, a clutch ring 49 having a plurality of radially disposed claws 51 is axially slidably provided on the end of the crank shaft 11 adjacent to the gear 43 so that its claws 51 may engage with the claws 45 of the gear 43. It will be understood that the clutch ring 49 having the claws 51 and the claws 45 of the gear 43 act jointly as a so-called dog clutch or claw clutch. As seen from FIG. 4, the clutch ring 49 is so arranged as to slide along a plurality of splines 53 formed on the end of the crank shaft 11 adjacent to the gear 43. Thus, when the claws 51 of the clutch ring 49 are kept in engagement with the claws 45 of the gear 43, the crank shaft 11 is rotated by the gear 43 to drive the ram 7, as long as the clutch and brake assembly 21 is transmitting the power from the flywheel 17 to drive the output gear 23. On the other hand, when the clutch ring 49 is slid along the splines 53 on the crank shaft 11 away from the gear 43 to bring its claws 51 out of engagement with the claws 45 thereof, the crank shaft 11 is no longer driven by the gear 43, even if the clutch and brake assembly 21 continues to transmit the power from the motor 15.
In order to bring the claws 51 of the clutch ring 49 into or out of engagement with the claws 45 of the gear 43, the clutch ring 49 is so arranged as to be pneumatically moved by a cylindrical plunger member 55 which may be a piston having a piston rod. As best shown in FIG. 4, the clutch ring 49 is fixed to the plunger member 55 by a pin 57 in such a manner as to radially project therefrom like a flange. On the other hand, the plunger member 55 is slidably inserted in an elongate cylindrical plunger chamber 59 which is formed through the axial center of the end of the crank shaft 11 and is provided at its inner end opposite to the gear 43 with a radially formed port 61 from which the air is supplied. In this connection, the radial port 61 of the crank shaft 11 is so formed as to right upwardly open when the crank shaft 11 is at its upper dead center to position the ram 7 at its uppermost travelling limit. Also, in order to enable the plunger member 55 and the clutch ring 49 to move together inside and outside the crank shaft 11, respectively, the crank shaft 11 is formed at its diametrically opposite portions adjacent to the gear 43 with a pair of axially elongate slots 63 in and along which the pin 57 is movable. Furthermore, the outer end of the plunger chamber 59 is closed by a lid member 65, and a spring 67 is inserted in the plunger chamber 59 between the plunger member 55 and the lid member 65 to bias the plunger member 55 away from the lid member 65. Thus, when the plunger chamber 59 is being supplied with the air from the radial port 61, the plunger member 55 is pressed against the spring 67 so as to keep the claws 51 of the clutch ring 49 in contact with the claws 45 of the gear 43. On the contrary, on discharge of the air from the plunger chamber 59, the plunger member 55 is moved by the spring 67 so as to bring the clutch ring 49 out of engagement with the claws 45 of the gear 43 to disconnect the crank shaft 11 from the power source.
As best shown in FIG. 4, the crank shaft 11 is journaled in a hub member 69 which is so fixed to a portion of the frame 3 of the press 1 as to hold a portion of the crank shaft 11 where the radial port 61 is formed to outwardly open. The hub member 69 is formed at its uppermost portion with a vertical inlet port 71 which is bored vertically and radially from the uppermost portion of the hub member 69 toward the axis of the crank shaft 11 on and along a vertical plane where the radial port 61 of the crank shaft 11 is rotated around the axis of the crank shaft 11. It will be readily apparent that the radial port 61 of the crank shaft 11 is connected with the radial inlet port 71 of the hub member 69 when the crank shaft 11 is at its upper dead center where the ram 7 is at its uppermost travelling limit, since the radial port 61 is so formed as to be right upwardly open when the crank shaft 11 is at its upper dead center as described hereinbefore. Also, as shown in FIG. 2, a conduit 73 having a check valve 75 is provided to connect the air source 35 with the port 71. Thus, the plunger chamber 59 is supplied with the air from the air source 35 through the conduit 73, the inlet port 71 of the hub member 69 and the radial port 61 of the crank shaft 11, each time when the ports 71 and 61 are connected with each other when the crank shaft 11 is rotated to its upper dead center to bring the ram 7 to its uppermost travelling limit.
As shown in FIGS. 2 and 3, the hub member 69 is formed with a radial outlet port 77 which is bored radially toward the axis of the crank shaft 11 at a slight angle "α" shown in FIG. 3 to the radial port 71 on and along the same plane as that where the radial port 71 is rotated around the axis of the crank shaft 11. The outlet port 77 is connected by a conduit 79 with a solenoid operated valve 81 which is normally closed. It will be understood that the radial port 61 of the crank shaft 11 is brought into connection with the outlet port 77 of the hub member 69 when the crank shaft 11 is rotated past its upper dead center through the angle "α".
The solenoid operated valve 81 is so arranged as to be operated by a limit switch 83 which is workable when contacted by a dog 85 fixed to a portion of the crank shaft 11. The limit switch 83 is so disposed as to be actuated by the dog 85 when the crank shaft 11 is rotated past its upper dead center through an angle "β" which is smaller than the angle "α" of the outlet port 77 as shown in FIG. 3. Also, the limit switch 83 is so arranged in a well-known manner as to be actuated by the dog 85 not when the crank shaft 11 is normally rotated but only when the crank shaft 11 is unintendedly rotated past its upper dead center to repeatedly move the ram 7 after a completion of its stroke without stopping at its uppermost travelling limit.
From the above description, it will be now understood that the ram 7 is stopped from unintendedly double stroking as soon as the crank shaft 11 begins to unintentionally rotate past its upper dead center. Of course, the crank shaft 11 is rotated by the clutch ring 49 in normal operations since the plunger member 55 is pushed to keep the clutch ring 49 in engagement with the claws 45 of the gear 43 by the air supplied into the plunger chamber 39 from the conduit 73. When the crank shaft 11 is unintentionally rotated through the angle "β" shown in FIG. 3 past its upper dead center, the limit switch 83 is actuated by the dog 85 in a well-known manner to make the solenoid operated valve 81 open. As the result, when the crank shaft 11 is rotated through the angle "α" to bring its radial port 61 into connection with the outlet port 77 of the hub member 69, the air acting on the plunger 55 in the plunger chamber 59 will be exhausted to the atmosphere through the conduit 79 and the solenoid operated valve 81. On exhaustion of the air from the plunger chamber 59, the plunger 55 is moved by the spring 67 to bring the clutch ring 49 out of engagement with the claws 45 of the gear 43. Accordingly, the crank shaft 11 is disconnected from the power source such as the gear 43 and is stopped from driving the ram 7, even if the clutch and brake assembly 21 continues to transmit the power. Accordingly, the ram 7 is softly stopped without shock from lowering by the air acting in the counterbalance means 25, although it is going to lower by inertia. Thus, it will be appreciated that the counterbalance means 25 act as buffers or shock-absorbers to softly or shocklessly stop the ram 7 against inertia without damaging any portion of the press 1 after the crank shaft 11 is disconnected from the power source.
Aside from the embodiment illustrated in FIGS. 2-4, the advantages of the present invention are also attainable with the second embodiment illustrated in FIGS. 5-7. The second embodiment will be described with use of the same numerals as the first embodiment shown in FIGS. 2-4 with regard to the elements common to both embodiments.
Referring to FIGS. 5 and 6, the crank shaft 11 shown as an eccentric shaft in the preferred embodiment is rotatably mounted on the ram 7 by means of bearings 87 and it is provided at its end adjoining the transmission 19 with a ring member 89 which is fixed thereto by a key 91 but may be formed as a flange thereon. As seen from FIG. 6, the ring member 89 is formed at its inner face with a plurality of radial depressions 89d which are equally spaced from each other and are formed to radially extend with equal widths so that a plurality of sector-like projections 89p are formed therebetween. An annular gear 93 is freely rotatably mounted on and around the ring member 89 by means of an annular bearing or bushing 94 so as to engage the output gear 23 of the transmission 19. As seen from FIG. 6, in order to hold the annular gear 93 on the ring member 89, the ring member 89 and the annular gear 93 are formed at their inner circumferential edges with a convex annular step and a concave annular step, respectively. The annular gear 93 is also formed at its inner face with a plurality of radial depressions 93d which are equally spaced from each other and are formed to radially extend with the same widths as the depressions 89d of the ring member 89 so that a plurality of sector-like projections 93p are formed therebetween. Also, a clutch ring 95 is provided around the crank shaft 11 in such a manner as to face with the depressions 89d and 93d and the projections 89p and 93p of the ring member 89 and the annular gear 93. The clutch ring 95 is provided at its face on the side of the ring member 89 and the annular gear 93 with a plurality of elongate claw members 97 which are as many as the depressions 89d and 93d of the ring member 89 and the annular gear 93. As seen from FIG. 7, the claw members 97 of the clutch ring 95 are equal in width to the depressions 89d and 93d of the ring member 89 and the annular gear 93 and equal in length to the added radial lengths of both of them. More particularly, the claw members 97 of the clutch ring 95 are radially arranged on the face of the clutch ring 95 so that they may be fitted in both the depressions 89d and 93d of the ring member 89 and the annular gear 93 to connect them with each other. It will be readily understood that when the clutch members 97 of the clutch ring 95 are engaged with both the depressions 89d and 93d of the ring member 89 and the annular gear 93, the crank shaft 11 is rotated by the output gear 23 through the annular gear 93, the clutch ring 95 and the ring member 89.
As best shown in FIG. 6, the ring member 89 is formed at its outer side opposite to its depressions 89d with an annular chamber 99 which has an equal width throughout its length and depth and extends circumferentially at an equal radial distance from the axis of the crank shaft 11. An annular piston member 101 having seal members 103 is slidably inserted in the annular chamber 99 so that it may be moved in the axial direction of the crank shaft 11. The annular piston member 101 is integrally connected with the clutch ring 95 by a plurality of elongate bolts 105 and cylindrical spacers 107 through bores 109 which are formed through the ring member 89 from the end of the annular chamber 99 in parallel with and at an equal radial distance from the axis of the crank shaft 11. More particularly, the elongate bolts 105 are inserted through the annular piston member 101, the cylindrical spacers 107 and the clutch ring 95 to integrally connect them all, and the cylindrical spacers 107 are slidably inserted in the bores 109. Also, a disk plate 111 is fixed to the ring member 89 by a plurality of bolts 113 to cover the end of the crank shaft 11 and hold the annular gear 93 in position on the ring member 89. As shown in FIG. 6, the disk plate 111 is formed with a plurality of openings 115 to allow the ends of the elongate bolts 105 to project out. Thus, when the annular chamber 99 is supplied with the air, the annular piston member 101 is moved in the annular chamber 99 to pull the clutch ring 95 by means of the elongate bolts 105 and the cylindrical spacers 107 so as to bring the claw members 97 of the clutch ring 95 into engagement with the depressions 89d and 93d of the ring member 89 and the annular gear 93.
As best seen from FIG. 6, a plurality of springs 117 are provided between the clutch ring 95 and the ring member 89 to bias the clutch ring 95 away from the ring member 89. In the preferred embodiment, the springs 117 are inserted in a plurality of bores 119 which are formed in the ring member 89 on its side facing with the clutch ring 95 in parallel with and at an equal radial distance from the axis of the crank shaft 11. Thus, the clutch ring 95 is pushed by the springs 117 away from the ring member 89 and the annular gear 93 to bring its claw members 97 out of engagement with their depressions 89d and 93d, when the air acting on the annular piston member 101 is exhausted from the annular chamber 99.
In order to supply and discharge the air into and from the annular chamber 99, there are provided a plurality of passages 121 which are formed through the ring member 89 to connect with the annular chamber 99. The passages 121 are connected with an elongate bore 123 which is formed through the axis of the crank shaft 11. In the preferred embodiments as shown in FIG. 6, the passages 121 are connected with the elongate bore 123 by a plurality of grooves 125 which are formed on the inner side of the disk plate 111 in such a manner as to radially extend from the end of the elongate bore 123 of the crank shaft 11. Therefore, the passages 121 are so formed as to rather radially extend from the annular chamber 99 to open to the radial inner circumference of the ring member 89 on the side of the disk plate 111. In this connection, a single one of the passages 121 and a single one of the grooves 125 may be provided for the plurality of them.
As shown in FIGS. 5 and 6, the elongate bore 123 is connected at its end opposite to the grooves 125 with a swivel joint 127 with which a conduit 129 is connected from the air source 35 through a solenoid operated valve 131. As seen from FIG. 5, the solenoid operated valve 131 is so arranged as to supply the air from the air source 35 normally when not energized and exhaust the air to the atmosphere when energized. Also, the solenoid operated valve 131 is so arranged as to be energized by a limit switch 83' which is workable when contacted by a dog 85' which is fixed to a portion of the crank shaft 11. The limit switch 83' is so arranged as to be actuated by the dog 85' to energize the solenoid operated valve 131 only when the crank shaft 11 has begun to unintendedly rotate past its upper dead center after a completion of a stroke of the ram 7 in all the same manner as the embodiment shown in FIGS. 2, 3 and 4. Thus, normally the air from the air source 35 is supplied from the conduit 129 through the swivel joint 127, the elongate bore 123, the grooves 125 and the passages 121 into the annular chamber 99 to enable the annular piston member 101 to hold the claw members 97 of the clutch ring 95 in engagement with the depressions 89d and 93d of the ring member 89 and the annular gear 93. However, once the crank shaft 11 has begun to rotate past its upper dead center, the solenoid operated valve 131 is energized by the limit switch 83' to allow the air to exhaust therethrough, and accordingly the springs 117 will push the clutch ring 95 to pull the claw members 97 out of engagement with the depressions 89d and 93d of the ring member 89 and the annular gear 93.
As shown in FIG. 6, a limit switch 133 and a dog member 135 are provided on a portion of the frame 3 of the press 1 in the vicinity of the clutch ring 95. The limit switch 133 is so arranged as to stop the motor 15 when contacted by the dog member 135, while the dog member 135 is so provided as to be pushed by the clutch ring 95 into contact with the limit switch 133 when the clutch ring 95 is moved out of engagement with the depressions 89d and 93d of the ring member 89 and the annular gear 93. In the preferred embodiment, the dog member 135 is slidably inserted in a cylindrical case 137 horizontally fixed to the frame 3 of the press 1 and is biased by a spring 139 toward the clutch ring 95, and it is provided at its end with a roller 141 to be touched by the clutch ring 95. Thus, when the clutch ring 95 is moved out of engagement with the ring member 89 and the annular gear 93 to disconnect the crank shaft 11 from the power source, the dog member 135 is pushed by the clutch ring 95 into contact with the limit switch 133 to stop the motor 15 from driving the press 1. Accordingly, once the crank shaft 11 has begun to unintendedly rotate past its upper dead center to allow the ram 7 to unintendedly double stroke, not only is the crank shaft 11 stopped from being driven by the annular gear 93 but also the press 1 is completely stopped from being driven by the motor 15.
Referring to FIGS. 5 and 6, in order to align radially the annular gear 93 in phase with the clutch ring 95, a proximity switch 143 is provided in the vicinity of the annular gear 93 on a bracket 145 fixed to a portion of the frame 3 of the press 1, and an actuating member 147 for actuating the proximity switch 143 is fixed to the radially outer edge of the outer side of the annular gear 93. In the well-known manner, the proximity switch 143 is so arranged as to generate a signal when the actuating member 147 is in the proximity thereof. Therefore, the actuating member 147 is so located on the annular gear 93 that it may be in the proximity of the proximity switch 143 when the claw members 97 of the clutch ring 95 are in engagement with the depressions 89d and 93d of the ring member 89 and the annular gear 93 with the crank shaft 11 put in a pre-determined rotational position. Thus, in order to align radially the annular gear 93 in phase with the clutch ring 95 it is only necessary to firstly rotate the crank shaft 11 to the pre-determined rotational position and then rotate the annular gear 93 on the ring member 89 until the proximity switch 143 signals that the actuating member 143 has come into the proximity thereof. Incidentally, it is necessary to align radially the clutch ring 95 in phase with the annular gear 93 after the clutch ring 95 has been moved out of engagement with the depressions 89d and 93d of the ring member 89 and the annular gear 93.
As is now apparent from the above description, the ram 7 is softly or shocklessly stopped by the counterbalance means 25 from unintendedly double stroking after a completion of a stroking cycle as soon as the crank shaft 11 begins to rotate past its upper dead center in the second embodiment as well as in the previously-described first embodiment. When the crank shaft 11 unintendedly begins to rotate past its upper dead center and the limit switch 83' is actuated by the dog 85' in the same well-known manner as in the first embodiment, the solenoid operated valve 131 is energized to allow the air pressurized in the annular chamber 99 to exhaust therefrom through the passages 121, the grooves 125, the elongate bore 123 of the crank shaft 11 and the swivel joint 127. Accordingly, the annular piston member 101 can no longer pull the clutch ring 95 against the springs 117 and the clutch ring 95 is pushed by the springs 117 to bring the claw members 97 out of engagement with the depressions 89d and 93d of the ring member 89 and the annular gear 93. Consequently, the ring member 89 is disconnected from the annular gear 93 to stop driving the crank shaft 11, and accordingly the ram 7 is no longer driven by the crank shaft 11 and is softly or shocklessly stopped from double stroking by the counterbalance means 25 without damaging any portion of the press 1. Also, as soon as the clutch ring 95 is pushed by the springs 117 away from the ring member 89 and the annular gear 93, the dog member 135 is pushed thereby into contact with the limit switch 133 to stop the motor 15. Furthermore, the annular gear 93 and the clutch ring 95 can be radially aligned in phase with each other by firstly turning the crank shaft 11 to a pre-determined rotational position and then rotating the annular gear 93 until the actuating member 147 is brought into the proximity of the proximity switch 143.
As has been so far described, according to the present invention, the crank shaft 11 is disconnected from the power source in the event that it begins to unintendedly rotate past its upper dead center to allow the ram 7 to double stroke after a completion of a stroke. Also, on disconnection of the crank shaft 11 from the power source, the ram 7 is softly or shocklessly stopped from double stroking by the counterbalance means 25 without damaging any portion of the press 1.
Although only preferred forms of the present invention have been illustrated and described herein, it should be understood that the device is capable of modification by one skilled in the art without departing from the principles of the invention. Accordingly, the scope of the invention is to be limited only by the claims appended hereto. | This disclosure relates to a method and apparatus for facilitating safe operation of mechanical presses. The press includes a press ram mounted on a crank shaft and adapted for reciprocatory movement along a vertical path between uppermost and lowermost points on the path. A motor is provided for turning the crank shaft through 360 degrees rotation including an upper dead center position. The press further includes main clutch and brake means for disconnecting the crank shaft from the motor and stopping the ram at the uppermost point of its path of travel after completion of a stroking cycle. At this point the crank shaft is at its upper dead center position. The press also includes an auxiliary clutch which is operatively connected in series with the main clutch and which is normally engaged for transmitting power from the motor to the crank shaft. The auxiliary clutch will be automatically disengaged if the crank shaft unintentionally rotates past its upper dead center position upon completion of a stroking cycle of the ram, thereby preventing a hazardous double stroke upon failure of the main clutch or the like. | 1 |
This is a continuation of Ser. No. 513,659 filed Oct. 10, 1974 a division of application Ser. No. 338,360 filed Mar. 5, 1973 now U.S. Pat. No. 3,854,200.
CROSS-REFERENCE TO A RELATED APPLICATION
This application is related to the application for an Improved Beta Brass Alloy and Method of Making Same, U.S. Ser. No. 107,118, filed Jan. 18, 1971 abandoned in lieu of continuation Ser. No. 508,098, now U.S. Pat. No. 4,014,716. Horace Pops is a common inventor for both applications. Both applications are owned by a common assignee.
BACKGROUND OF THE INVENTION
Many techniques have been employed to produce integrated circuit packages. Beam lead, spider, flip chip and others are methods known to those skilled in the art. These known methods are expensive, not entirely reliable and require many separate and distinct processing steps.
For example, the chip and wire technique involves ultrasonic welding of a large number of extremely fine aluminum wires as leads to pads on the semiconductor chip. In the even that any one of these bonds is defective, the entire package would be rejected as a product.
It has previously been suggested by Wetmore in U.S. Pat. No. 3,243,211 that a heat activated, recoverable nonconductive plastic may be used to fasten or hold wire leads together. The heat recoverable material upon being heated will encapsulate and hold the wire leads or conductors in a fixed relative position. Such a construction would be impractical for the small components of an integrated circuit package.
It has also been suggested by Otte in U.s. Pat. No. 3,588,618 that a conductive metal with a shape memory may be used as a lead material. The lead will normally be bent to connect with a second lead at a solder connection. Upon reheating the soldered connection to melt the solder, the leads will separate due to the shape memory effect of the particular alloy utilized to make the lead. As a result, components associated with the separated leads may be easily removed for repair or the like.
So far as it is known, however, no material or process has been devised utilizing the shape memory effect or similar effects for manufacture of integrated circuit packages. This invention is directed to such a process and product.
SUMMARY OF THE INVENTION
In a principal aspect, the present invention comprises an improved method for making an integrated circuit assembly of the type which includes at least one lead attached by a conductive bond such as a solder material to at least one component. The method of the invention utilizes the so-called "shape memory effect" as well as a new effect discovered by the inventors and defined as the "reverse shape memory effect." A lead is fabricated from a chosen alloy and then strained to a first position. Subsequently, the lead is heat treated to initiate the shape memory effect and cause the lead to be positioned for bonding with the component. Alternatively, the shape memory effect may be instituted following application of strain but before positioning the lead for contact with a conductive bond. The lead is then positioned and the reverse shape memory effect is initiated to move the lead into contact with a conductive bond material.
It is thus an object of the invention to provide an improved method for making an integrated circuit assembly which, by virtue of the composition of lead material and the steps in the method, provides a simple and economical process for manufacture of an integrated circuit assembly.
It is another object of the present invention to provide a method for effecting a reverse shape memory effect in a beta brass composition.
Still another object of the present invention is to provide a method for effecting a shape memory effect in a beta brass composition in order to manufacture an integrated circuit assembly.
One further object of the present invention is to provide a method of forming an integrated circuit assembly utilizing the shape memory effect of the beta brass composition.
These and other objects, advantages and features of the invention will be set forth in the detailed discussion which follows.
BRIEF DESCRIPTION OF THE DRAWING
In the detailed description which follows, reference will be made to the drawing comprised of the following figures:
FIG. 1 is a processing flow chart of the steps for fabrication of an integrated circuit assembly in accordance with the present invention;
FIG. 2 is a schematic flow diagram illustrating the methods of assembly set forth in the chart in FIG. 1;
FIG. 3 is a graph of angular movement versus strain, indicating the amount of shape memory and reverse shape memory observed in a number of alloys used to practice the invention;
FIG. 4 is a graph illustrating the amount of strain recovery from a strain manifested by various alloys utilized to practice the invention; and
FIG. 5 is a plan view of a typical lead frame made in accordance with the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Incorporated herewith by reference is the application by co-inventor Pops, Ser. No. 107,118, filed Jan. 18, 1971. This copending application discloses a number of typical alloys which exhibit a shape memory characteristic. The definitions of shape memory and betatizing as set forth in this co-pending appliation are incorporated herewith by reference also. That is, betatizing constitutes heat treatment of the alloy to provide a substantially continuous beta phase.
Referring to FIGS. 2 and 5, a lead frame 10 is comprised of a frame member 11 and a plurality of leads or fingers 12 extending therefrom. Typically, the frame 10 is stamped or etched from a flat sheet of desired conductive metal or alloy material. The fingers 12 which extend from the frame member 11 connect to various portions or pads of a semiconductor chip 14 as illustrated schematically in FIG. 2. Thus, each of the fingers 12 is engaged by a conductive bond 16 which is, in this instance, solder, to effect an electrical connection with the chip 14.
The fingers 12 can engage the solder or bond composition 16 on the chip only if the fingers 12 move or are moved a sufficient distance out of the plane of the frame member 11 to engage and be bonded to the bond composition or molten solder 16. The movement of the fingers 12 is effected in accordance with the invention by either of two stress assisted, thermally activated processes.
The first of these processes is identified as the shape memory effect or characteristic. As a result of this effect, material which is strained at room temperature, for example, will nearly resume the original, unstrained configuration upon being heated. That is, it will move opposite to the direction of strain. Note also that the strained material is normally an alloy having a beta phase and a martensite phase and that the strain is effected at a temperature generally below the M s temperature or slightly above. This was described in some detail in the prior application cited above.
The second process is the reverse shape memory effect characteristic. This effect is not believed to have been observed or reported previously. The reverse shape memory effect provides that after being strained the material will move in the direction of the strain upon the application of heat. Movement is thus in a direction which is opposite to that due to the shape memory characteristic. Again, strained material is generally in a martensitic phase and the strain is effected at a temperature below the M s or slightly above.
It should be noted that the shape memory and reverse shape memory effects are distinct from the so-called rubber-like (pseudo-elastic or super-elastic) behavior observed in many materials. The rubber-like behavior occurs spontaneously upon release of a stress to substantially reverse the strain applied by a stress. Generally, the stress is applied above the M s temperature in order to observe "rubber-like" behavior.
Following are additional details regarding first the composition, and second, the specific steps in the method of the invention. This will be followed by specific examples of the invention.
Composition
Copper, zinc and silicon are the materials which provide an alloy that can be utilized to practice the method of the invention. Broadly, 62-65% by weight copper, 35-38% by weight zinc and 0.3-0.5% by weight silicon are combined to form a beta brass alloy. The specific composition utilized in most of the experimental work reported herein consists of (1) 62.19% by weight copper, 37.37% by weight zinc, and 0.44% by weight silicon or (2) 63.20% by weight copper, 36.18% by weight zinc and 0.46% by weight silicon. Both of these compositions provide a beta phase brass or mixed alpha plus beta brass at room temperature after betatization. The martensite transformation temperature of this brass is determined as reported in the previous application Ser. No. 107,118, filed Jan. 18, 1971. It is desirable to keep this transformation temperature near room temperature since the process of the invention is related, at least in part, to phase changes of the material. In the alloys discussed above, the start of the martensite transformation upon cooling occurs at temperature about -55° C ± 20° C and 13° C±20° C, respectively.
Method of the Invention
FIG. 1 illustrates three flow charts which show the method of the invention. All of these three methods represented by the flow chart utilize the shape memory effect of the alloy from which the lead frame is made. In addition, two of the methods utilize the reverse shape memory effect.
To review, inducing the shape memory effect in the alloys discussed above involves deformation of the betatized alloy at a temperature below the martensite transformation temperature or slightly above. In either case, the material should contain an appreciable quantity of martensite phase. Upon heating the alloy above the martensite transformation temperature, but generally less than 400° C., the deformed alloy material will almost resume its original configuration. This is illustrated in FIG. 3. The process involved is the transformation of the deformed martensite phase into the beta phase.
To initiate the reverse shape memory effect, deformation of the martensite phase when the alloy is below the transformation temperature is necessary. In addition, the material may also be deformed at temperatures slightly above the martensite transformation temperature. Following deformation, the material is heated to a higher temperature range than that employed to initiate the normal shape memory effect. Typically, this range is between 230° and 550° C. for the alloys tested. The process occurs isothermally, thereby requiring that the alloy be held at temperature for a minimum time. As a result of the reverse shape memory effect, the material moves in the direction of original strain.
The process involves decomposition of the deformed material into a bainitic phase. Relative movement of the alloy occurs during the transformation into the bainitic type phase in accordance with FIG. 3. In contrast to the shape memory effect, movement during the reverse shape memory effect takes place in the direction of original deformation.
For example, if a typical beta brass alloy of the type defined above is strained on the order of 10% at 25° C., it exhibits a 32% shape recovery at 200° C. It moves 32% toward its original position or away from the direction of bending upon heating to 200° C. The same material also exhibits a 45% movement toward the direction of bending or deformation upon continued heating for 1 second at 450° C. This continued movement toward the direction of deformation constitutes the reverse shape memory effect.
Examples
Method I
A ternary brass alloy composition of 63.2% copper, 36.1% zinc and 0.46% silicon was processed to 6 mil strip by conventional melting and rolling methods. In this form, it consists of a duplex mixture of α and β phases. Lead frames of the design shown in FIG. 5 were photo-chemically etched (fabrication by stamping or any other method is permissible) from the α+β material. The lead frame fingers 12 were bent 90° about a mandrel having a 0.040 inch bend radius (corresponding to a 7% strain on the outer fiber). Each of the lead frames was betatized by heating to 830° C. (any temperature in the β phase field is permissible, namely 800° → 850° C.) for 5 minutes, and quenched into water to retain the high temperature β phase.
Deformation of the martensite phase is accomplished by flattening the lead frames at ambient temperature. The lead frames are now positioned above the semiconductor chips 14 and heated to a temperature of 200° C. Shape-memory occurs during heating, causing each of the fingers to move simultaneously into the molten solder 16.
Method II
The α + β alloy strip is fabricated into lead frames by photo-chemical etching. They are betatized and quenched in an identical manner as described above. The same amount of bending (7% strain) is used on the fingers 12 but in this case, it is applied to a β phase material or martensite, if the Ms temperature is above room temperature. Heating to 200° C. produces shape-memory and tends to flatten the fingers. After cooling to room temperature, the (nearly) flat lead frames are positioned above the solder bumps, and the package is placed in a furnace at 450° C. Since "reverse-shape memory" occurs (within 2 minutes) the deformed fingers move in the direction of bending and hence, make contact with the molten solder 16. A minimum movement of 10 mils in the vertical direction is required; this is possible to achieve with the copper-zinc-silicon alloys.
Method III
Alternatively, Method III may be employed and, in fact, is the preferred procedure since betatization is accomplished continuously with minimum distortion. A description of the continuous fabrication technique is contained in the previous patent application Ser. No. 107,118. A strip of α+β is heated to its betatization temperature (830° C), discharged from the furnace, and immediately quenched by cold steel rolls or any other metallic conductor, and a coolant spray. Lead frames are fabricated from the heat treated strip, as described in Methods I and II. Bending of the fingers 90° (7% strain on the other fiber) is subsequently performed at room temperature.
Flattening occurs by a shape-memory process, and is produced by heating the deformed lead frames to 200° C. Following alignment above the chip, the package is placed in an oven for 2 minutes at 450° C. This final step simultaneously produces reverse-shape memory, movement of the fingers in a downward direction, and bonding of the lead frame to the chip.
Note that in each of the examples, the materials are polycrystalline, wrought or worked materials. That is, the product and process of the present invention is possible because the alloys chosen exhibit the reverse shape memory and shape memory characteristics when in a polycrystalline, worked condition. These phenomena are not generally observed in such worked materials nd therefore the product and process of the present invention is considered unexpected.
While in the foregoing there has been set forth a preferred number of embodiments of the invention, it is to be understood that the invention shall be limited only by the following claims and their equivalents. That is, other materials exhibit the shape memory characteristic. Consequently, the methods of the present invention may be utilized to practice the invention. | A method for making an integrated circuit package includes the steps of fabricating lead frames from a copper-zinc-silicon beta brass alloy and soldering the leads thereof to semi-conductor chips by use of the shape memory and reverse shape memory characteristic of the alloy. The composition of the lead frame material and the choice and sequence of fabrication steps may be varied. | 2 |
[0001] This is a continuation-in-part of U.S. patent application Ser. No. 11/064,187, filed Feb. 23, 2005, from which priority is claimed.
FIELD OF THE INVENTION
[0002] The present invention relates generally to therapeutic hypothermia.
BACKGROUND OF THE INVENTION
[0003] Intravascular catheters have been introduced for controlling patient temperature. Typically, a coolant such as saline is circulated through an intravascular heat exchange catheter, which is positioned in the patient's bloodstream, to cool or heat the blood as appropriate for the patient's condition. The coolant is warmed or cooled by a computer-controlled heat exchanger that is external to the patient and that is in fluid communication with the catheter.
[0004] For example, intravascular heat exchange catheters can be used to combat potentially harmful fever in patients suffering from neurological and cardiac conditions such as stroke, subarachnoid hemorrhage, intracerebral hemorrhage, cardiac arrest, and acute myocardial infarction, or to induce therapeutic hypothermia in such patients. Further, such catheters can be used to rewarm patients after, e.g., cardiac surgery or for other reasons. Intravascular catheters afford advantages over external methods of cooling and warming, including more precise temperature control and more convenience on the part of medical personnel.
[0005] The following U.S. patents, all of which are incorporated herein by reference, disclose various intravascular catheters/systems/methods: U.S. Pat. Nos. 6,419,643, 6,416,533, 6,409,747, 6,405,080, 6,393,320, 6,368,304, 6,338,727, 6,299,599, 6,290,717, 6,287,326, 6,165,207, 6,149,670, 6,146,411, 6,126,684, 6,306,161, 6,264,679, 6,231,594, 6,149,676, 6,149,673, 6,110,168, 5,989,238, 5,879,329, 5,837,003, 6,383,210, 6,379,378, 6,364,899, 6,325,818, 6,312,452, 6,261,312, 6,254,626, 6,251,130, 6,251,129, 6,245,095, 6,238,428, 6,235,048, 6,231,595, 6,224,624, 6,149,677, 6,096,068, 6,042,559.
[0006] Surface cooling may be less optimally used. For example, externally applied cooling pads are disclosed in U.S. Pat. Nos. 6,827,728, 6,818,012, 6,802,855, 6,799,063, 6,764,391, 6,692,518, 6,669,715, 6,660,027, 6,648,905, 6,645,232, 6,620,187, 6,461,379, 6,375,674, 6,197,045, and 6,188,930 (collectively, “the external pad patents”), all of which are incorporated herein by reference.
[0007] Regardless of the modality of cooling, it is believed that the sooner a patient is cooled after ischemic insult, the better the therapy. The present invention recognizes that many patients will have their first encounter with health care personnel in ambulances, prior to being afforded the opportunity for critical care such as controlled maintenance of hypothermia. Thus, it would be advantageous, as understood herein, to provide a means to bring cooling on board to patients as soon as possible.
SUMMARY OF THE INVENTION
[0008] A system for controlling patient temperature includes a closed loop heat exchange catheter configured for placement in the circulatory system of a patient to exchange heat with the blood of the patient. The system also includes a source of cold fluid, with the cold fluid being colder than normal body temperature and infusable from the source into the patient without using the catheter.
[0009] The catheter may be configured for percutaneous advancement into the central venous system of the patient. The catheter can carry coolant that is not infused into the bloodstream of the patient.
[0010] In another aspect, a method for treating a patient using hypothermia includes injecting cold saline into the venous system of the patient while the patient is located in an ambulance or in an emergency room of a hospital. Then subsequently hypothermia is maintained in the patient using an external heat exchange pad or an intravascular heat exchange catheter while the patient is in an operating room of a hospital or an intensive care unit of a hospital.
[0011] In yet another aspect, a method for treating a patient includes infusing into the patient's venous system a cold fluid having a temperature lower than a temperature of the patient to cause the fluid to mix with the blood of the patient and thereby to cool the patient. The method also includes engaging a cooling apparatus with the patient to maintain a desired hypothermic condition in the patient.
[0012] In additional embodiments, a system for controlling patient temperature includes a closed loop heat exchange catheter configured for placement in the circulatory system of a patient to exchange heat with the blood of the patient, and an external heat exchange bladder configured for exchanging heat with the skin of a patient. The system also includes a heat exchange system in a single housing and engageable with both the catheter and the bladder.
[0013] In non-limiting implementations of this last embodiment, the housing can include a sensor which detects when the heat exchange system is connected to the bladder, and potentially to the catheter as well, to provide a signal to a controller in the housing. Additionally, a controller may be in the housing and receive a patient temperature signal from a BTT sensor. Further, an IV bag can be supported on the housing for infusing cold saline directly into the bloodstream of a patient.
[0014] Continuing to summarize non-limiting implementations, the heat exchange system may include a coolant loop configured for exchanging heat with a working fluid loop associated with the catheter. The coolant loop may also be configured for direct fluid communication with the bladder. Or, the heat exchange system can include a coolant loop having a coldwell, with the catheter being associated with a catheter working fluid loop including a catheter coil disposable in the coldwell and with the bladder being associated with a bladder working fluid loop including a bladder coil disposable in the coldwell. Both working fluid loops may be associated with respective pumps. The heat exchange system may also include an internal reservoir for priming the bladder, and may control both the catheter and bladder simultaneously. The heat exchange system can include a refrigerant loop including a compressor and one or more heat exchangers communicating with the compressor.
[0015] In another aspect, a heat exchange system includes a coolant loop, at least a first working fluid loop in thermal communication with the coolant loop and an intravascular heat exchange catheter associated with the first working fluid loop such that working fluid circulates through the heat exchange catheter without entering the patient's bloodstream when the catheter is positioned in the bloodstream. At least one external heat exchange member is configured for placement against a patient's skin to heat or cool the skin. The external heat exchange member is configured for heat transfer using the coolant loop.
[0016] In another aspect, a method for patient temperature control includes providing a heat exchange system, and engaging an intravascular heat exchange catheter with the system and with a patient to exchange heat with the patient. The method also includes engaging at least one bladder with the system and placing the bladder against the patient's skin to exchange heat with the patient.
[0017] In other aspects, a patient temperature control system includes at least one bladder through which working fluid can flow. The bladder is positionable against the skin of a patient, and a skin conditioning hydrogel can be disposed between the bladder and the skin.
[0018] In another aspect, a patient temperature control system includes at least one bladder through which working fluid can flow, with the bladder being configured as the front of a garment and having a trunk portion and two opposed limb portions that can drape over the patient.
[0019] In another aspect, a patient temperature control system includes at least one bladder through which working fluid can flow. The surface of the bladder facing away from a patient when the bladder is positioned against the skin of the patient is backed by a foam that conforms to pressure caused by the weight of the patient.
[0020] The details of the present invention, both as to its structure and operation, can best be understood in reference to the accompanying drawings, in which like reference numerals refer to like parts, and in which:
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 is a schematic diagram showing two modalities of controlled hypothermnia maintenance in a patient, along with an apparatus for quickly reducing patient temperature;
[0022] FIG. 2 is a flow chart of logic;
[0023] FIG. 3 is a diagram of a single heat exchange chassis system that supports both an external cooling bladder and an intravascular temperature control catheter;
[0024] FIG. 4 is a schematic diagram showing that the heat exchange system can have two heat exchangers in parallel with one compressor;
[0025] FIG. 5 is a schematic diagram of an alternate system;
[0026] FIG. 6 is a cross-section of a non-limiting quick disconnect feature as would be seen along the line 6 - 6 in FIG. 5 ;
[0027] FIG. 7 is a schematic diagram of an alternate system; and
[0028] FIG. 8 is a schematic diagram of an alternate system.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0029] Referring initially to FIG. 1 , a system is shown, generally designated 10 , that includes a heat exchange catheter 12 that is in fluid communication with a catheter temperature control system 14 .
[0030] In accordance with present principles, the system 10 can be used to induce therapeutic hypothermia in a patient 16 using a catheter in which coolant circulates in a closed loop, such that no coolant enters the body. While certain preferred catheters are disclosed below, it is to be understood that other catheters can be used in accordance with present principles, including, without limitation, any of the catheters disclosed in the following U.S. patents, all incorporated herein by reference: U.S. Pat. Nos. 5,486,208, 5,837,003, 6,110,168, 6,149,673, 6,149,676, 6,231,594, 6,264,679, 6,306,161, 6,235,048, 6,238,428, 6,245,095, 6,251,129, 6,251,130, 6,254,626, 6,261,312, 6,312,452, 6,325,818, 6,409,747, 6,368,304, 6,338,727, 6,299,599, 6,287,326, 6,126,684. The catheter 12 may be placed in the venous system, e.g., in the superior or inferior vena cava.
[0031] Instead of or in addition to the catheter 12 , the system 10 may include one or more pads 18 that are positioned against the external skin of the patient 16 (only one pad 18 shown for clarity). The pad 18 may be, without limitation, any one of the pads disclosed in the external pad patents. The temperature of the pad 18 can be controlled by a pad controller 20 in accordance with principles set forth in the external pad patents to exchange heat with the patient 16 , including to induce therapeutic mild or moderate hypothermia in the patient in response to the patient presenting with, e.g., cardiac arrest, myocardial infarction, stroke, high intracranial pressure, traumatic brain injury, or other malady the effects of which can be ameliorated by hypothermia.
[0032] To cool the patient while awaiting engagement of the catheter 12 and/or pad 18 with the patient, cold fluid 22 in a cold fluid source 24 may be injected into the patient and in particular into the patient's venous system through a pathway 26 . Without limitation, the pathway 26 may an IV line, the source 24 may be an IV bag, and the fluid 22 may be chilled saline, e.g., saline at the freezing point or slightly warmer. Or, the source may be a syringe, and the saline can be injected directly into the bloodstream of the patient.
[0033] Now referring to FIG. 2 , at block 28 the patient presents with symptoms indicating that the application of hypothermia is appropriate. For instance, the patient may have cardiac arrest, and may be resuscitated. Or, the patient may present with myocardial infarction or stroke or other malady.
[0034] At block 30 , cold saline 22 is immediately (in the case of cardiac arrest patients, immediately after resuscitation) injected into the patient's bloodstream, preferably at a venous site, using the source 24 . This can occur in, e.g., an ambulance on the way to the hospital for further temperature management, and/or in the hospital emergency room. Hypothermia treatment including the establishment and maintenance of mild or moderate hypothermia subsequently is effected at block 32 using the catheter 12 and/or pad 18 , typically in the operating room or intensive care unit of a hospital, although in some hospitals the step at block 32 may begin while the patient is still in the emergency room or even while the patient is still in the ambulance.
[0035] The above three modalities of cooling—intravascular closed loop catheter, external pad/bladder, and cold saline bolus infusion—may be supported by a single housing.
[0036] With greater specificity, FIG. 3 shows details of one non-limiting single-chassis heat exchange system, generally designated 100 , which includes a single heat exchange system housing 102 holding all or portions of three fluid loops. Specifically, a refrigerant loop 104 exists in which refrigerant flows between a compressor 106 and at least one heat exchanger 108 . Exiting the heat exchanger 108 , the refrigerant passes through a CP valve 110 to a condenser 112 , which condenses the refrigerant. The refrigerant loop 104 may be replaced by a thermoelectric cooling loop in which the fluid is air passing over and cooling a TEC element.
[0037] In the heat exchanger 108 , the refrigerant expands to cool a coolant in a coolant loop 114 , which is in thermal but not fluid contact with the refrigerant loop 104 . The coolant may be water, propylene glycol, a mixture thereof, or other suitable coolant. Also included in the coolant loop 114 is a heater 116 for heating the coolant to, e.g., re-warm a patient, and a coolant pump 118 to circulate the coolant through the coolant loop 114 . The coolant pump may be a magnetically-coupled non-displacement pump, or a positive displacement pump.
[0038] FIG. 3 shows that the coolant flows into a chamber defined by a coldwell 120 , which may be the highest point in the system. A catheter fluid loop coil 122 may be disposed in the coldwell 120 in thermal but not in fluid contact with the coolant. The catheter fluid loop coil 122 defines part of a working fluid loop 124 through which a working fluid such as saline flows. The fluid in the working fluid loop 124 circulates, under the influence of a working fluid pump 126 , which can be a peristaltic pump, through an intravascular heat exchange catheter 128 without exiting the catheter into the bloodstream. The working fluid exchanges heat with the coolant in the coldwell 120 . A saline bag 130 may be provided in the working fluid loop 124 for priming purposes, and an air trap 132 may also be provided to prevent any air that might exist in the working fluid loop 124 from entering the catheter 128 . The entire working fluid loop 124 may be provided as a standalone catheter start-up kit, with the catheter fluid loop coil 122 disposed by medical personnel in the coldwell 120 and with the catheter 128 then being advanced into the vasculature of a patient to exchange heat with the patient. Additional details of the non-limiting system 100 may be found in the present assignee's U.S. Pat. Nos. 6,146,411, 6,581,403, and 6,529,775, all of which are incorporated herein by reference, and in U.S. patent application Ser. No. 10/944,544, filed Sep. 17, 2004, also incorporated herein. The above patents further disclose non-limiting ways in which a controller/power supply 133 controls various of the components above to heat or cool the working fluid as necessary to achieve a user-set target temperature. A patient temperature sensor 133 a can send a patient temperature signal to the controller 133 as shown. The sensor 133 a may be any suitable sensor including, without limitation, a brain temperature tunnel (BTT) sensor to sense the temperature through thin peri-occular skin of a sinus, which represents the temperature of the brain.
[0039] Still referring to FIG. 3 , in lieu of placing the catheter fluid loop coil 122 in the coldwell 120 and the catheter 128 in the patient, a bladder cooling loop coil 134 , which is part of a bladder fluid loop 136 , may be disposed in the coldwell 120 . A bladder fluid pump 138 , which can be a positive displacement pump, circulates working fluid, which could be tap water or saline or other appropriate fluid, through the loop 136 . Included in the loop 136 is an externally-applied bladder 140 through which the working fluid flows to cool a patient. The bladder 140 may be any suitable cooling device such as a conformal pad or a mattress that is placed against the skin, including any of the devices referred to previously. An adhesive or non-adhesive hydrogel and/or a silver sulphur diazene cream or zinc paste may be disposed between the bladder and patient. Or, a skin conditioning hydrogel such as glycerol in sorbolene can be used. The bladder itself may be configured as the front of a shirt or trousers, i.e., with a trunk portion and two opposed limb portions that can drape over the patient. The surface of the bladder that faces away from the patient can be backed by a NASA foam that conforms to. pressure caused by the weight of the patient to reduce the risk of bedsores.
[0040] A saline bag 142 may be provided in the loop 136 for priming. Also, a three-way stopcock 144 can be provided as shown to isolate the bag 142 . The loop 136 may be controlled by a separate bladder controller/power supply 146 , which may communicate with the controller 133 if desired.
[0041] An IV pole 147 may be mounted on the housing 102 and may support an IV bag 148 , for infusing cold saline in the IV bag directly into the bloodstream of the patient as shown. A coil 149 may be provided in communication with the IV bag. The coil 149 may be disposed in the coldwell 120 to cool saline in coil, which can circulate under the influence of a pump 149 a.
[0042] FIG. 4 shows that for greater heat exchange power, a compressor 150 may circulate refrigerant through two heat exchangers 152 , 154 , either in parallel with each other or with one of the heat exchangers isolated by means of a computer-controlled solenoid valve 156 . The arrangement shown in FIG. 4 could be used in lieu of the arrangements shown in the other figures herein.
[0043] FIG. 5 shows the coolant loop portion 200 of an alternate system 202 , which in all essential respects is identical to the system 100 shown in FIG. 3 with the following exceptions. Coolant such as water may flow, under the influence of a coolant pump 204 , through a heat exchanger 206 and a computer-controlled three-way valve 208 , which either sends the coolant to a coldwell 210 to exchange heat with the coil of an intravascular catheter as described above, or to a bladder loop 212 that includes an external heat exchange bladder 214 as shown. A priming reservoir 216 , which can be internal to the chassis of the system 202 , may be provided for priming the bladder 214 with coolant, it being understood that in some embodiments the coldwell itself can be used for priming instead, in which case an additional three-way valve between the coldwell and first three-way valve 208 could be required for establishing the appropriate fluid flow control.
[0044] In any case, as shown in FIG. 5 the bladder 214 is connected to a supply line 218 and a return line 220 , with the lines 218 , 220 terminating in respective bladder fittings 222 , 224 that engage respective system fittings 226 , 228 on the chassis of the system 202 . Preferably, the fittings are quick disconnect fittings that provide an indication of engagement and disengagement to the controller (not shown) of the system 202 for establishing the position of the three-way valve 208 for catheter or bladder operation as appropriate. Thus, in FIG. 5 the coolant loop supplies either the coldwell for exchanging heat with the working fluid circuit of the intravascular catheter, or it supplies the bladder directly.
[0045] It is undesirable that the heat exchanger freeze during, e.g., priming. Accordingly, when the system detects the bladder being connected, it can maintain system fluid temperatures above the freezing point. In any case, to avoid skin damage it is preferred that when the bladder is used the coolant temperature be maintained between four and forty two degrees Celsius.
[0046] A non-limiting example of quick disconnect fittings (using 224 , 228 as examples) is shown in FIG. 6 . As shown, the bladder fitting 224 may be circumscribed by a collar 230 , and as the bladder fitting 224 is advanced into the system fitting 228 , the collar 230 deflects a ball 232 that is reciprocally disposed in the wall of the system fitting 228 and that is urged inwardly (toward the bladder fitting 224 ) as shown by a spring 234 . As the ball 232 deflects, it actuates a sensing element 236 on the system fitting 228 to provide an “engaged” signal to the system controller, which can then reconfigure the user interface and/or control parameters used for establishing patient temperature. Or, the ball and spring can be omitted and the collar seat against the sensing element when the fittings are engaged, to actuate the sensing element. Other arrangements known in the art may be used. The sensing element 236 may be an electrical contact or other suitable element known in the art. It is to be understood that the catheter start-up kit shown in FIG. 3 may also be connected to the system using such fittings, so that in any of the embodiments herein, the controller “knows” which device or devices, catheter and/or bladder, is connected.
[0047] FIGS. 7 and 8 show alternate embodiments in which a bladder 300 is part of a bladder working fluid loop 302 that includes a bladder coil 304 disposable in a bladder coldwell 306 , it being understood that the catheter-related working fluid loop shown in FIG. 3 with separate catheter coldwell and catheter working fluid loop pump is also provided in a system that includes the refrigerant loop and working fluid loop shown in FIG. 3 . In essence, in the systems of FIGS. 7 and 8 two separate working fluid loops are provided, one for the external cooling bladder and one for the intravascular catheter, with both loops being controlled by a common controller, e.g., the controller 303 shown in FIG. 3 . In any case, a bladder working fluid loop pump 308 provides the motive force for circulating the working fluid. Either an external saline bag 310 ( FIG. 7 ) can be provided for priming through a three-way stopcock 312 , or a reservoir 314 ( FIG. 8 ) that is internal to the system chassis can be provided. In both cases, a supply line 316 to the coil 304 and a return line 318 from the bladder 300 (or from the stopcock 312 when one is used as shown in FIG. 7 ) terminate in quick-disconnect fittings 320 , 322 as shown, for operation as described above to alert the system controller to whether the bladder is connected. In the embodiments shown in FIGS. 7 and 8 , since two separate working fluid loops are provided, both the catheter and the bladder can be.simultaneously controlled by the controller to heat or cool a patient. Or, if simultaneous catheter/bladder use is not required, the bladder loop may not include its own coldwell and pump but rather can use a single coldwell that services either catheter and bladder.
[0048] While the particular SYSTEM AND METHOD FOR BRINGING HYPOTHERMIA RAPIDLY ONBOARD as herein shown and described in detail is fully capable of attaining the above-described objects of the invention, it is to be understood that it is the presently preferred embodiment of the present invention and is thus representative of the subject matter which is broadly contemplated by the present invention, that the scope of the present invention fully encompasses other embodiments which may become obvious to those skilled in the art, and that the scope of the present invention is accordingly to be limited by nothing other than the appended claims, in which reference to an element in the singular is not intended to mean “one and only one” unless explicitly so stated, but rather “one or more”. All structural and functional equivalents to the elements of the above-described preferred embodiment that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the present claims. Moreover, it is not necessary for a device or method to address each and every problem sought to be solved by the present invention, for it to be encompassed by the present claims. Furthermore, no element, component, or method step in the present disclosure is intended to be dedicated to the public regardless of whether the element, component, or method step is explicitly recited in the claims. No claim element herein is to be construed under the provisions of 35 U.S.C. §112, sixth paragraph, unless the element is expressly recited using the phrase “means for” or, in the case of a method claim, the element is recited as a “step” instead of an “act”. | An intravenous heat exchange catheter and/or an external cooling pad/bladder can be used to maintain hypothermia in, e.g., a cardiac arrest patient, but to accelerate the cooling process the patient first can be infused with cold saline before the opportunity arises to connect the catheter or pad to the patient. | 0 |
This application claims the benefit under 35 U.S.C. 119(e) of the filing date of Provisional U.S. Application Ser. No. 60/857,983, entitled Design and Method for a Dripless Liquid Wash Aid Pumping Mechanism, filed on Nov. 8, 2006. This provisional application is expressly incorporated herein by reference in its entirety. This application is also related to co-pending U.S. application Ser. No. 11/437,427, entitled Bulk Dispensing of Chemicals Into a Residential Dishwasher, filed on May 19, 2006 and commonly assigned herewith, which application is also herein expressly incorporated by reference in its entirety.
FIELD OF THE INVENTION
This invention relates generally to chemical dispensing systems, and more particularly, to systems for bulk dispensing of chemicals, such as detergents, into a residential dishwasher.
BACKGROUND OF THE INVENTION
Typically, residential dishwashing machines include built-in single-dose detergent dispensers. A single-dose dispenser must be re-filled every time the dishwashing machine is to be used, which requires an extra step. Additionally, manual filling of the dispenser cup often leads to accidental overfilling or underfilling.
What is needed, therefore, is a bulk detergent dispenser that does not need to be refilled every time that it is used, and can automatically dispense the correct amount of detergent, at the right time or times during the machine's operating cycle.
SUMMARY OF THE INVENTION
The inventive dispensing system comprises a detergent reservoir that can hold liquid gel dish detergent in bulk quantities, preferably comprising the contents of at least one bottle of detergent as sold at retail, which is disposed inside the dishwasher. The reservoir is filled with detergent from the inside of the door, to facilitate clean-up if any product is accidentally spilled. As a result, the dishwasher is made easier and more convenient to use, by reducing the repetitive step of loading detergent and allowing “peace of mind” delegation of the dishwashing task.
Metered dosage control is an added benefit of the present invention.
More particularly, in one aspect of the invention, there is provided a fluid dispensing system for a dishwasher, particularly for residential use, wherein the dishwasher comprises a housing, a wash chamber enclosed by the housing, and a door for accessing the wash chamber. The dispensing system comprises a fluid reservoir adapted to be disposed in the door for containing fluid (preferably liquid dishwashing detergent) which may be used to treat dishes in the wash chamber during a dish cleaning cycle. The system further comprises a pump which is adapted to be disposed in the door, in proximity to the reservoir, for dispensing a predetermined quantity of the fluid from the reservoir into the dishwasher wash chamber one or more times during the dish cleaning cycle. The pump preferably comprises a reciprocating plunger pump, and is solenoid-actuated.
The reservoir has a fluid capacity sufficient for a plurality of dish cleaning cycles without the need for replenishment. In preferred embodiments, the reservoir fluid capacity is approximately equal to the capacity of a typically sized single container of fluid (typically dishwashing detergent) available at retail, so that the consumer may empty the entire contents of the container (bottle) into the reservoir at one time, and then dispose of the container.
In addition to dishwashing detergent, the fluid contained in the reservoir may comprise a dishwasher rinse aid. In one embodiment of the invention, two reservoirs are provided, one of which contains dishwashing detergent, and the other of which contains dishwasher rinse aid.
The above described predetermined quantity (metered dosage) of fluid is preferably adjustable responsive to either controller or user input. Controller input might include, for example, feedback from dish soil sensors which cause the controller to adjust detergent levels to address the sensed soil concentrations. User input might include, for example, depressing a particular dish cycle selector button on the dishwasher, such as “normal cycle” or “pots and pans cycle”.
In particular, the dishwasher door described above comprises an interior panel having a recess sized to accommodate the reservoir. The reservoir is thus adapted to be disposed in the recess, in flush-mounted fashion. The reservoir is preferably adapted to be snap-fit into the recess and to be retained therein because of an interference fit. It is adapted to be removed from the recess and re-installed in the recess without using tools, for easy clean-up or re-filling, if desired. It should be noted, however, that the reservoir may also be readily re-filled while installed in the door panel. The reservoir includes an inlet, and may be filled and re-filled with fluid through the inlet. In one alternative embodiment, the reservoir is pre-filled with fluid, and disposable once empty, and is not re-Tillable with additional fluid. The reservoir is preferably translucent, so that a level of fluid remaining in the reservoir may be readily determined by a user.
The pump may also be removed and installed without using any tools.
In another aspect of the invention, there is provided a dishwasher for residential use, which comprises a housing and a wash chamber enclosed by the housing. A door is provided in the housing for accessing the wash chamber. A fluid reservoir is disposed in the door for containing fluid (preferably liquid dishwashing detergent) which may be used to treat dishes in the wash chamber during a dish cleaning cycle. A pump is also disposed in the door, in proximity to the reservoir, for dispensing a predetermined quantity of the fluid from the reservoir into the wash chamber one or more times during the dish cleaning cycle. The pump preferably comprises a reciprocating plunger pump, and is solenoid-actuated.
In yet another aspect of the invention, there is provided a method for washing dishes in a residential dishwasher during a dish cleaning cycle, which comprises a step of actuating the dish cleaning cycle, and a further step of actuating a dispenser pump in a door of the dishwasher, for dispensing a metered dosage of dish detergent from a reservoir in said door into a wash chamber in the dishwasher. A further step comprises actuating the dispenser pump a second time during the dish cleaning cycle to dispense a further metered dosage of dish detergent from the reservoir into the wash chamber. In one example of such an operational mode, the first step may occur during a pre-wash cycle, and the second step may occur during a main wash cycle. The dispenser pump actuation step is preferably performed using a solenoid actuator. When the dispenser pump is actuated, a plunger in the pump reciprocates in one direction to draw a metered dose of detergent into a pumping chamber, after which the plunger reciprocates in an opposing direction to dispense the detergent in the pumping chamber into the wash chamber.
In a further aspect of this method, an additional step comprises removing the reservoir from the door, cleaning the reservoir, and replacing the reservoir back into the door, without the use of any tools.
In still another aspect of the invention, there is provided a fluid dispensing system for a dishwasher, wherein the dishwasher comprises a housing, a wash chamber enclosed by the housing, and a door for accessing the wash chamber. The dispensing system, in particular, comprises a fluid reservoir for containing a wash aid which may be used to treat dishes in the dishwasher wash chamber during a dish cleaning cycle. It further comprises a pump for dispensing a predetermined quantity of the wash aid from the reservoir into the dishwasher wash chamber and into the reservoir from a supply reservoir one or more times during the dish cleaning cycle. A dual purpose check valve is provided for controlling fluid flow in two opposing directions between the pump and the fluid reservoir.
Preferably, the dual purpose check valve comprises a duckbill valve portion for controlling fluid flow in a first direction, and an umbrella valve portion for controlling fluid flow in an opposing second direction.
The invention, together with additional features and advantages thereof, may be best understood by reference to the following description taken in conjunction with the accompanying illustrative drawings. In these accompanying drawings, like reference numerals designate like parts throughout the figures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a residential dishwasher which is equipped with a bulk detergent dispenser feature in accordance with the present invention;
FIG. 2 is a perspective view of the bulk detergent dispenser of FIG. 1 , shown in isolation;
FIG. 3 is a perspective view of the interior of the dishwasher door, showing the bulk detergent dispenser of FIG. 2 installed therein;
FIG. 4 is a perspective view illustrating the fluid connection between the dispenser reservoir and liquid pump shown in FIG. 2 ;
FIG. 5 is a perspective view illustrating the solenoid installation;
FIG. 5A is an enlarged view of a portion of FIG. 5 , showing the solenoid installation more clearly;
FIG. 6A is a perspective view of one embodiment of the liquid detergent pump of the present invention;
FIG. 6B is a perspective view of the liquid detergent pump of FIG. 6A , shown in cross-section in order to illustrate the internal mechanisms of the pump;
FIG. 7A is a perspective view of an umbrella check valve which may be employed in the present invention;
FIG. 7B is a perspective view of check valve seats which may be employed in the present invention;
FIG. 7C is a schematic view illustrating the function of the check valves employed in the present invention;
FIG. 8 is a perspective view illustrating the detergent pump discharge structure;
FIG. 9 is a perspective view of the dish detergent dispenser of FIGS. 1-8 , illustrated in an exploded view the construction of the detergent pump;
FIG. 10 is a perspective view similar to FIG. 2 , illustrating a modified embodiment of the dispenser of the present invention which comprises both a detergent and a rinse aid dispenser;
FIG. 11 is a perspective view, from the rear, showing the embodiment of FIG. 10 ;
FIG. 12 is a plan view of a modified embodiment of the present invention, showing the installation of a detergent reservoir in the door of a dishwasher;
FIG. 13 is a schematic view of a further modified embodiment of the present invention;
FIG. 14 is a front view of a another embodiment of a wash aid pumping system for a residential dishwasher, constructed in accordance with the principles of the present invention;
FIG. 15 is a side view of the system illustrated in FIG. 14 ; and
FIG. 16 is a cross-sectional view taken along lines A-A of FIG. 15 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, there is shown a residential dishwasher 10 having a hinged door 12 and a main housing 14 . The dishwasher 10 provides a method for storage and injection of chemicals into the washing chamber 16 thereof. The device is designed to store one complete container of the most common-sized chemical found in the market. The device can inject a plurality of chemicals (detergents and rinse aids are the most common), which are supplied in a liquid state.
A detergent reservoir 18 is flush-mounted inside the door 12 of the dishwasher 10 , and is filled via a fill spout 20 . A wide, easy-fill quarter-turn lid 22 is recessed within the fill spout 20 to prevent over-filling of the reservoir. A reservoir 18 is supplied with the dishwasher and is reusable for the lifespan of the dishwasher, in one embodiment, but in an alternative embodiment, a ready-to-use disposable cartridge, formed by inexpensive blow-molding techniques to fit the provided recess in the door, is pre-filled with detergent and sold to the consumer for installation directly into the door reservoir recess. In this alternative embodiment, a simple cap, rather than the illustrated wide lid, is provided, since there is no necessity for the consumer to fill the reservoir, and thus no chance of spillage. The reservoir further includes a hydrophobic vent (not shown) to ensure that the detergent reservoir 18 does not collapse when dispensing product. The vent is preferably a labyrinth-seal type vent to allow air movement in both directions, but excludes water from entering the reservoir or detergent from weeping out. Air enters the reservoir when the detergent is dispensed, through the vent, in order to prevent the reservoir from collapsing. As the temperature rises during the operating cycle of the appliance, expanding air inside the reservoir exits through the vent.
Advantageously, the reservoir 18 may be transparent or translucent to permit an operator to readily determine the detergent level in the reservoir. Alternatively, other known gauging systems may be employed.
The inventive dish detergent dispenser comprises four components. In addition to the reservoir 18 , the dispenser comprises a dispenser pump 24 ( FIG. 2 ), a solenoid actuator 26 , and a circuit board/controller (not shown). All of the components 18 , 24 , 26 are mounted in the door 12 . The circuit board/controller may be mounted anywhere on the dishwasher, including the door, as long as the selected location is sealed from contact with liquids in order to protect the electronics. The controller electronically controls the dispensing function for precision and differentiation.
As noted above, and referring particularly to FIGS. 2 and 3 , both the detergent reservoir 18 and the dispenser pump 24 are semi-flush mounted inside recesses within the door 12 , as illustrated in FIG. 3 . Both components snap in easily to the inside face of the door, with an interference fit, as shown. The reservoir's interference fit with respect to the recess is a rather loose one, owing to the relatively thin-walled construction of the reservoir. On the other hand, the interference fit of the pump in its respective recess is rather tight, owing to the relatively thick-walled construction of the pump body.
The solenoid actuator 26 is mounted behind the door panel, which may be fabricated of stainless steel or other suitable materials, for safety and protection. The reservoir 18 is preferably designed to hold the contents of one “grocery store” bottle. Since the fill location 22 of the reservoir 18 is inside the dishwasher, spill clean up is easy. The semi-flush mounting design makes the reservoir of a sufficiently low profile so that it does not interfere with the lower rack as it slides in and out, nor does it substantially reduce usable tub volume (volume of the washing chamber 16 ).
As shown in FIG. 4 , engaging seals 28 , 30 on the reservoir 18 and the pump 24 , respectively, allow the reservoir and pump to be easily snapped together with a tight seal. The same interface design is provided for the alternative embodiment (not shown) discussed above, which employs a pre-filled recess-fitting detergent cartridge.
FIGS. 5 and 5A illustrate, in tiled figures, the rear side of the inner door panel 12 , so that the solenoid can be seen behind the panel, on the “dry” side of the panel. As can be seen, only one access hole 32 is provided in the panel 12 , for accommodating the connector 34 between the solenoid 26 and the pump 24 . Preferably, a soft elastomeric accordion seal (not shown) is employed to seal this hole 32 , which provides a low stress seal even with lots of axial movement. Such a static seal ensures lifetime leak-free performance.
As shown in FIGS. 6A and 6B , the preferred detergent pump 24 has few parts. The one moving part is actually part of the solenoid actuator 26 . As noted previously, the pump 24 is wetted in the dishwasher, while the solenoid 26 is isolated on the dry side of the panel. The pump is a simple plunger pump, comprising a detergent batch chamber 36 having an inlet port 38 , a pumping chamber 40 , defined by a reciprocating plunger 42 , a pumping chamber inlet port 44 , and a pumping chamber outlet port 46 . The plunger 42 is driven by the solenoid actuator 26 and preferably includes wiper seals for sealing the pumping chamber 40 . Any weeping past the wiper seals goes into the wash chamber 16 , where the detergent is destined to go anyway. The plunger is spring-loaded, and is normally extended all the way into the pumping chamber. Energizing the solenoid 26 causes the plunger to retract, drawing liquid from the batch chamber 36 to the pumping chamber 40 through the pumping chamber inlet port 44 . De-energizing the solenoid actuator 26 causes the spring to relax, extending the plunger 42 and thus dispensing detergent from the pumping chamber 40 through the pumping chamber outlet port 46 . Advantageously, large passages and short flow paths are employed to permit free movement of thick gel detergent.
Now with reference particularly to FIGS. 7A , 7 B, and 7 C, an umbrella check valve 48 is preferably employed in each of the pumping chamber inlet and outlet ports 44 , 46 , respectively. Valve seats 50 for each of the inlet and outlet ports are shown in FIG. 7B . Umbrella check valves are preferred because they comprise soft elastomers that move easily and have low stress. As shown in FIG. 7A , an extended piece 52 is employed to pull the valve through the mounting hole. This piece 52 is designed to break off after pull-through, during assembly. The valve seats 50 utilize large passages in order to maintain low liquid resistance. A plug 54 ( FIG. 7C ) is disposed in the discharge passage in order to finish the pump.
FIGS. 8 and 9 illustrate additional details of the inventive dispensing system.
In operation, when the dishwasher door 12 is opened, the pump batch chamber 36 is filled. When the door is closed, excess detergent runs out of the batch chamber, leaving a full batch of predetermined volume of detergent behind. The “full batch” of detergent typically includes a smaller volume for a pre-wash cycle and a larger volume for a main wash cycle. In one particular embodiment, for example, a full batch is approximately 60 ml, including 20 ml for a pre-wash cycle and 40 ml for a main wash cycle, but these values may vary, depending upon application and specifications of the particular dishwasher in which the dispenser is disposed. Also, when the door is closed, the detergent level in the main reservoir drops below the batch chamber fill port to prevent re-filling.
This main reservoir/batch chamber design effectively isolates the main reservoir from water contamination. Water would need to flow against two check valves, then up and over the spillway to gain access to the main chamber.
Each stroke of the solenoid pushes a small amount of detergent into the dishwasher wash chamber, through a discharge passage 56 . A full pre-wash dose typically requires a few strokes. A full dose of main wash requires more strokes. For example, in one particular embodiment, each stroke of the solenoid dispenses approximately 4 ml of detergent into the wash chamber. In this embodiment, five strokes of the solenoid supplies sufficient detergent for a pre-wash cycle and ten strokes of the solenoid supplies sufficient detergent for a main wash cycle. Of course, these particular values are exemplary only, and subject to dishwasher specifications, soil load, and the like.
The batch chamber 36 need not be emptied on every wash cycle. It is all right to utilize less detergent for a particular load and to leave the chamber partially filled. It should be noted that the detergent pump discharge passage 56 is preferably wide and short, for two primary reasons. One reason is to ensure that there is absolutely minimal liquid resistance for the pump to overcome. The second reason is so that spray water from the washing chamber 16 splashes the passage 56 clean, but cannot get past the pump outlet passage umbrella valve 48 .
In FIGS. 10 and 11 , there is shown a modified embodiment of the detergent reservoir 18 , which includes a second reservoir 58 , for dispensing a rinse aid or the like. A second dispenser pump 60 and solenoid actuator 62 may be utilized to dispense the rinse aid. As presently embodied, the rinse aid dispensing system essentially duplicates the detergent dispensing system described above.
Three versions of the inventive detergent dispensing system are currently contemplated. A first, basic version dispenses a fixed amount (40 ml in one exemplary embodiment) of detergent automatically when called upon by the dishwasher. This version may or may not allow prewash dosing. A second, more sophisticated version dispenses a variable amount of detergent, the adjustment being enabled using an electrical dial on the control panel of the dishwasher, often located on the door. The volume ranges from “minimum” to “normal”, to “heavy load”. A third, even more sophisticated version dispenses a variable amount of detergent driven from a soil load sensing technology, which is a sensor system having a capability of detecting the level of soil present on the dishes being washed. In this version, the consumer also has the option of overriding with a manual volume dial.
Now with reference to FIG. 12 , a modified embodiment of the reservoir and pump of the present invention is illustrated. In this embodiment, a detergent reservoir 18 ′ is flush-mounted in an inside panel of a dishwasher door 12 ′. The reservoir 18 ′ has a lid 22 ′ for closing a fill spout 20 ′. The lid 22 ′ is of the “flip-top” type, and may be flipped between the illustrated closed position, and an open position for filling the reservoir 18 ′. A fingertip recess 64 is provided for enabling a user's fingertip to engage and open the lid 22 ′. A dispenser pump 24 ′ is provided directly beneath the reservoir 18 ′, as shown, having a fluid discharge passage 56 ′. The pump 24 ′ is constructed in a similar manner to that discussed above with respect to pump 24 . An advantage of this embodiment is to improve flow of fluid from the reservoir into the pump, because of the immediate proximity of the reservoir outlet to the pump inlet.
In FIG. 13 there is shown yet another modified embodiment of the invention, including a reservoir 18 ″ having a lid 22 ″ similar to the lid 22 of the first illustrated embodiment. Again, at the base of the reservoir 18 ″, which is adapted for disposition in a dishwasher door, as in prior embodiments, is a dispenser pump 24 ″. The dispenser pump 24 ″ comprises a solenoid actuator 26 ″ and a discharge passage 56 ″. In this embodiment, as in the FIG. 12 embodiment, fluid flow from the reservoir into the pump is facilitated by the immediately proximity of the pump inlet beneath the reservoir outlet.
Now, with particular reference to FIGS. 14-16 , yet another embodiment of a pump useful in combination with the foregoing dishwasher fluid dispensing system will be described. The dispenser pump 24 comprises a dripless pump mechanism having a single dual purpose check valve 66 that incorporates both an input and output function.
The dual purpose check valve 66 , as shown, operates as a duckbill check valve for the input of the wash aid, such as a detergent or rinse aid, and an umbrella shaped check valve for the output of wash aid to the wash chamber. The arrangement of the duckbill and umbrella function can also be reversed, if desired.
The dual purpose check valve 66 is attached to a piston cylinder body 68 that on one end incorporates an aperture 69 a to receive the duckbill valve component 69 b of the dual purpose valve 66 . Surrounding the aperture 69 a that receives the duckbill valve 69 b are openings 69 c arranged circumferentially to the hole. The outer edge of these openings are within the diameter of the umbrella portion 69 d of the dual check valve. Within the piston body 68 is a unibody piston 70 that incorporates two seal rings 72 , 74 . These seal rings create a minimum interference to the cylinder wall. The seal rings are oriented in opposing directions. The first seal ring 72 faces the dual-purpose check valve 66 on one end of the cylinder body 68 , while the second seal ring 74 faces in the opposite direction.
The unibody piston 70 includes a mating surface to the dual purpose check-valve 66 so that when the piston is in a fully dispensed position there is virtually no residual wash aid remaining in the space between the first seal ring 72 and the duck bill feature of the dual purpose check valve 66 . In addition, when the piston is in the fully dispensed position (piston moved to its left-most position), the piston incorporates a feature that captures the duckbill valve portion 69 b so that the tip of the valve is permanently pinched off when not in use.
When the pump mechanism is in the fully dispensed position, there is no liquid drip or seepage. This is due to a combination of the following advantageous features, which are discussed above:
a. there is minimized space between the first sealing ring 72 and the duckbill portion 69 b of the dual valve 66 , which prevents leakage out of the pump system by way of the umbrella valve portion 69 d ; and b. the duckbill valve portion 69 b is pinched off, which prevents seepage of the liquid into the pump body.
Another advantageous feature of this embodiment is a dripless reservoir-to-pump connection. More particularly, an interconnection between a reservoir 18 for the wash aid and the pump 24 is made using a tube 76 . The tube 76 , when connected to the pump body 68 , probes into the inside diameter of the duckbill check valve 69 b in the pump body, which then creates a conduit between the fluid-filled reservoir 18 and the pump input.
In one embodiment, the tube 76 is connected to the duckbill check valve portion 69 b on the reservoir side of the pump 24 . The tube 76 probes into the inside diameter of the duckbill check valve portion 69 b , which then creates a conduit between the fluid-filled reservoir 18 and the pump input, as discussed above. However, this duckbill check valve portion 69 b is now connected to the reservoir.
In an alternative approach, there is a reservoir cap 78 , wherein one end 80 of the hollow tube 76 extends from the center of the cap 78 into the interior of the reservoir 18 . The end of the tube incorporates a disengageable cap, integral membrane, or TPE valve 82 . During attachment of the reservoir 18 to the pump 24 , the reservoir cap 78 is pushed onto the end of the tube 76 . This tube 76 then penetrates the reservoir cap 78 via an inlet at the surface of the reservoir cap and dislocates or pierces the inner cap components. This connection creates a conduit between the fluid-filled reservoir and the pump body.
The reservoir cap 78 is preferably vented, thus venting the reservoir 18 in order to prevent back suction or reservoir collapse. The vented reservoir cap or plug incorporates, preferably, a straw-like component. This straw extends from the cap end of the reservoir to the opposite end thereof at the deepest location of the reservoir. During dispensing of the liquid wash aid, air is pulled into the inner volume of the reservoir, through the straw member, as the liquid exits through the tube 24 . An equal volume of air will always replace the displaced liquid, preventing the reservoir from vacuum collapsing. Alternative venting schemes may be employed, if desired.
While this invention has been described with respect to various specific examples and embodiments, it is to be understood that various modifications may be made without departing from the scope thereof. Therefore, the above description should not be construed as limiting the invention, but merely as an exemplification of one preferred embodiment thereof. | A fluid dispensing system for a dishwasher is disclosed, wherein the dishwasher comprises a housing, a wash chamber enclosed by the housing, and a door for accessing the wash chamber. The dispensing system, in particular, comprises a fluid reservoir for containing a wash aid (such as detergent or a rinse aid) which may be used to treat dishes in the dishwasher wash chamber during a dish cleaning cycle. The system further comprises a pump for dispensing a predetermined quantity of the wash aid from the reservoir into the dishwasher wash chamber and into the reservoir from a supply reservoir one or more times during the dish cleaning cycle. A dual purpose check valve is provided for controlling fluid flow in two opposing directions between the pump and the fluid reservoir. The dual purpose check valve comprises a duckbill valve portion for controlling fluid flow in a first direction, and an umbrella valve portion for controlling fluid flow in an opposing second direction. | 0 |
[0001] This application is a continuation-in-part of Ser. No. 10/021/365.
TECHNICAL FIELD
[0002] This invention relates to inhibition of enzymes, especially to inhibition of microbial enzymes, and enzymes catalyzing development of neoplasms and metabolic dysfunctions, via interrelations of enzymes, ions, and ion exchanging compositions and/or ion adsorbents.
BACKGROUND OF THE INVENTION
[0003] As stated by Bohinski [1], in Modern Concepts in Biochemistry , “the totality of cellular activity is intimately dependent on the type and concentration of ionic materials within the cell, both of which are subject to change by alterations in the extracellular environment.” As stated by Dressler and Potter [2] in Discovering Enzymes , “Not to put too fine a point on it, enzymes control all of the chemical transformations in the living world.”
[0004] Enzyme-controlled reactions are essential to all phenomena of life. Nearly every cellular activity is catalyzed by enzymes, many of the enzymes dependent upon associated cofactors. Though differences between those cofactors may not be sharp-edged, Holum's proposition [3] lists three generally accepted categories of cofactors (also see a schematic thereof in FIG. 1 ), thus:
[0005] a) a coenzyme: a non-protein organic substance (e.g., a vitamin) dialyzable, thermostable, and loosely attached to an apoenzyme; a true substrate for enzyme-catalyzed reaction, recycled in a later step of a metabolic pathway by another enzyme;
[0006] b) a prosthetic group: a dialyzable and thermostable organic substance, firmly attached to the protein of the apoenzyme portion; and
[0007] c) a metal cation activator, metal cations being critical to enzyme function, structure, and stability.
[0008] In general, the more complex an organism, the more complex and numerous its enzymes, and the more likely it can survive some enzymatic irregularity, such as inadequate concentration, or absence of a given enzyme. Whereas metabolism in vertebrates depends upon a vast number of enzymes, whose activity may require presence of other enzymes, coenzymes, or similar cofactors, more primitive life forms (e.g., viruses, bacteria, protozoa, fungi) survive with fewer enzymes, often controlled only by an ion activator, and may have their metabolism or replication terminated by dysfunction of a single enzyme. The present invention views ions, which activate or otherwise control activity or stability enzymes as targets, with objectives to deactivate, inhibit, or destabilize enzymes, and thereby to neutralize pathogens, control development of neoplasms, and undesirable metabolic processes—with minimal collateral damage to their respective hosts.
[0009] Current methods of inhibiting microbial enzymes rely mostly upon activity of chemical agents; limited in degree upon such other means as heat treatment, radiation, immunization, hormone application, or genetic engineering. However, all of these approaches often have severe limitations and/or serious side effects. Researchers focus upon chemical enzyme inhibitors, usually antibiotics or other chemicals, administered to the host organism, and often causing eventual deleterious side effects. Some of them interfere with cell division, and often are toxic to both host and invader, while many of them may contribute to development of resistant mutation of targeted and/or non-targeted pathogens.
[0010] The present invention directs attention to adsorption of ions necessary for biocatalysis, via ion exchangers. Since the vast majority of enzymes, for practical purposes of present invention, are enzymes activated or otherwise controlled by cations, the main attention is directed to the enzyme inhibition by cation exchangers such as hydrous aluminosilicate compositions or synthetic cation exchangers, here exemplified specifically by zeolites. However, all processes and methods for inhibition of metalloenzymes, and for the preparation and modification of cation exchangers—as disclosed in this invention—are analogically applicable for inhibition of anion-dependent enzymes, and for the preparation and modification of anion exchangers, as well as organic ionexchanger such The more detailed disclosure of zeolitic inhibition of enzymes is presented by way of example rather than limitation.
[0011] Both natural and synthetic zeolites are well known as adsorbents, carriers and ion exchangers of ionic substances often intended to catalyze or to inhibit certain chemical activity. Sometimes zeolites are used, either solitary or distributed within an organic polymer, to convey a toxin, a chelate, or a heavy metal cation as a bactericide or fungicide, as in cosmetics and medicines. See, for example, Yoshimoto et al. U.S. Pat. No. 4,870,107 (1989); Hagiwara et al. U.S. Pat. No. 4,775,585 (1988), U.S. Pat. No. 4,911,898 (1990), U.S. Pat. No. 4,959,268 (1990), Satoshi et al. Japanese Patent Application 03218916 A (1991); Satoshi et al. Japanese Patent Application 03255010A (1991); Wagner U.S. Pat. No. 4,824,661 (1989); and Barry U.S. Pat. No. 6,365,130 B1 (2002). In Chu et al. U.S. Pat. No. 5,140,949 (1992), for example, a mixture of zeolite and clay is proposed as a feed supplement, and as a topical treatment, based on its ability to adsorb ammonium cations. Similarly, in Polak et al. U.S. Pat. No. 5,409,903 (1995), zeolite alone, or zeolite in a mixture of other chemicals, is proposed for the treatment of Helicobacter pylori and dermatitis. U.S. Food Additive Regulation 582-2727 approves zeolite use in feeds as an anti-caking agent, and USDA approves them in food processing applications; being in EPA compliance (40 CFR, Part 180.1001 and elsewhere). Engler U.S. Pat. No. 5,900,258 features silicates, de-aluminated but neither deionized nor homoionized, to inhibit microorganism growth on and within textile and other interstitial or porous materials, also on relatively impervious extensive structural or working surfaces, and in nutrient material fed to chickens in order to evaluate its possibility for reducing incidence of microorganisms in or arising from such feed. All of the foregoing efforts are of minor interest. Other specific uses of zeolites as carriers of substances harmful to biological, sometimes enzyme-dependent, activity also could be cited, but also are distinct from the present invention.
SUMMARY OF THE INVENTION
[0012] A primary object of the present invention is inhibition of enzymes, via adsorptive removal of their ions serving either as catalytic cofactors or as structural stabilizers or both, by ion exchangers.
[0013] Another object of the present invention is an adsorptive removal of ions from the immediate environment of targeted enzymes, thus preventing microbes and neoplasms from utilizing them for replenishment or for production of new enzymes.
[0014] A further object is to extend the present invention as a different approach to inhibition of enzymes in areas of medicine, cosmetics, dentistry, agriculture, and food processing.
[0015] One more object is to provide an alternative to antibiotics.
[0016] Yet another object of this invention is to inhibit any biotype, serotype or other induced or spontaneous mutation of microbes, including drug-resistant strains.
[0017] An additional object of the invention is to deactivate proteinaceous biotoxins (e.g., snake and insect toxins)—an objective that cannot be achieved by antibiotics.
[0018] Another object of this invention is to provide effective means of prophylaxis, to limit likelihood of infection from contaminated air, liquids, foodstuffs, bodily surface contact, etc.
[0019] A still further object is to accomplish the foregoing objects in an economically sound way and in a manner safe to the human organism.
[0020] In general, the objects of this invention are achieved by inhibiting activity of microbial and neoplastic enzymes, enzymes causing metabolic dysfunctions, and proteinaceous biotoxins, by supplying to the site of that activity an ion exchanger—for example a properly constituted aluminosilicate—effective to adsorb ions and related substances provocative of such undesirable biochemical activity.
[0021] By a synergic action, aluminosilicates appropriately selected, such as to density and size of pores, are adapted to serve as molecular sieves to bind entire specific molecules, e.g., toxins. This ability of suitable aluminosilicates is a practical expedient often resorted to in the substance-separation industries.
[0022] Alteration in relative affinities of natural zeolites for given monovalent and divalent cations, by dry heating pretreatment, and the benefits of doing so are disclosed in Taborsky U.S. Pat. Nos. 5,082,813; 5,162,276; and 5,304,365. Zeolites or equivalent compositions may be ion-pretreated, e.g., by deionization, or by homoionization, or may be synthesized in specific (e.g., hydrogen) cation form, and be applied as a broad-range adsorbent, or may be selectively reionized for specific applications. Equivalent compositions may be combined for complementary and/or synergic purposes and/or for their affinities for ions or classes thereof.
[0023] Other objects of the present invention, together with means and methods for attaining the various objects, will become readily apparent from the following description, presented by way of example rather than limitation.
SUMMARY OF THE DRAWINGS
[0024] FIG. 1 comprises three schematized representations of a complete enzyme, comprising an apoenzyme (A) in separate conjunction with each of several different cofactors: (a, b, c).
[0025] FIG. 2 is a schematized representation of a zeolite (Z), in conjunction with each of a zinc activated protease (DP) and a tripartite toxin (LF+OF+PA) as in a digestive enzyme.
DESCRIPTION OF THE INVENTION
[0026] The invention is characterized in practical terms, so as to enable its successful practice, regardless of any academic or theoretical conceptualization expressed in this exposition thereof, as concurrence in the latter is not a prerequisite for successful practice of the actual invention.
[0027] Whereas “ionization” generally means a process of producing ions, in this description “ionization” and its inflected forms (e.g., reionization, homoionization) have the meaning of charging or loading an ion exchanger with ions—as a logical opposite of the unambiguous term “deionization” (being a conventional term for removing ions). The term “adsorbent” means an ionexchanger with most of its ion exchangeable sites unoccupied.
[0028] For all practical purposes, principles and methods of enzyme inhibition of bacteria, viruses, neoplasms, and metabolic dysfunctions via adsorption of their activating, stabilizing, or otherwise controlling ions by ion exchangers are identical. However, for demonstration of such inhibition bacteria are most suitable, as in the instant example of bacteria of the Bacillus anthracis group.
[0000] Preliminary Testing of inhibition of enzyme activity by zeolitic adsorption was conducted using the accepted ninhydrin (1,2,3-triketohydrindene hydrate) test for presence of amino acids from enzymatic breakdown of casein.
[0029] 1. At room temperature, 100 mg of bacterial protease was stirred into 100 ml of distilled water containing 10 g of deionized (method 2Bd) clinoptilolite particles (<74 μm). After about 10 minutes of mild agitation, 10 ml of this solution was stirred thoroughly into 50 ml of 5% DIFCO isoelectric casein solution, which tested negatively as to free amino acids an hour thereafter. This test indicated that the bacterial protease was deactivated, or the activating and/or stabilizing cations were depleted from the casein solution, or both.
[0030] 2. To avoid possible confusion by an eventual interaction between casein and zeolite, the test was modified as follows: at room temperature, 100 mg of bacterial protease was stirred into 100 ml distilled water containing 10 g of deionized (method 2Bd) clinoptilolite particles (300>600 μm). After about 10 minutes of mild agitation, the suspension was filtered through a 200 μm nylon sieve, then 10 ml of the filtrate was stirred thoroughly into 50 ml of 5% DIFCO isoelectric casein solution, which then tested negatively for free amino acids an hour thereafter. This result indicated that the bacterial protease was deactivated.
[0031] 3. Test 2 was then conducted in a more refined process by circulation of the therein specified solution in 10× larger volume through a bed of clinoptilolite particles (300>600 μm). It should be noted that some enzyme species are able to replenish their needed ions from their environment within some limited time after deactivation, and therefore, the time lapse before inoculation should be adjusted accordingly.
[0032] The zeolite adsorbed cations from the enzyme and inhibited it from breaking the casein down and providing amino acids for detection. Similar tests were conducted with different species of zeolite (phillipsite, chabazite), with deionized and H + homoionized samples from different sources, and with synthetic zeolites (Y, Beta, and ZMS-5 powders), and all test results indicated inhibition of the protease.
[0033] Further analogous tests indicated that all previously used deionized and H + homoionized natural and synthetic zeolites inhibited all tested bacteria, but tests with virgin natural zeolites were not entirely conclusive, suggesting a need for pretesting of each batch thereof, or for limiting actual operations to use of aluminosilicates pretreated as specified here, operative both in vitro and in vivo, such as for agriculture, dentistry, medicine, and biological instances generally.
[0034] Analogous tests to inhibit the (Cl − ) anion-activated α-amylase by an anion exchanger (resin A-SIP OH) indicated positive results. However, a cation exchanger can achieve the inhibition of the same enzyme also via adsorption of Ca ++ , which is necessary for stability of α-amylase.
[0000] Selection, Modification, and Applicability of Aluminosilicates.
[0035] The aluminosilicates, especially zeolites are customarily used as ion exchange media, in effecting separation and recovery of dissolved materials, liquids and gases, as carriers of ions. and specifically as molecular sieves (e.g. for cracking petroleum fractions). Aluminosilicate minerals occur in many geographical locations and include prominently zeolites: clinoptilolite, chabazite, phillipsite, analcite, brewsterite, faujasite, ferrierite, flakite, gmelinite, leucite, stilbite, and yugawaralite; also the layer (or pseudo-layer) silicates, vermiculites and smectites—often called layered clays; bentonites, and kaolinites.
[0036] The foregoing natural minerals are hydrated mixed aluminosilicates, with compositions determined largely by the constituents available when they were formed, resulting in diverse crystalline structures. Synthetic zeolites have been produced with more controlled compositions, and often are designated by a letter (e.g., “F”, “X”) appended to “zeolite.”Whether produced under laboratory conditions or in mineral deposits, these ion exchangers range widely in composition and physical properties. Their identification, as well as their properties, can vary, depending upon specific interesting characteristics—here, their physical properties, modification and manipulation of accessible surfaces and sites for adsorption of cations.
[0037] Ion exchangeable aluminosilicates have a distinctive molecular arrangement causing a negative charge of their molecules. It results in strong adsorptive power, unmatched by any other adsorbent and strong enough to penetrate the protective coats of vegetative forms of microbes, and moist-swollen exosporia, and protective coats of endospores. A similar transfer of cations through gels has been well demonstrated (see section 7B below: Application of aluminosilicate enzyme inhibitor). Aluminosilicates form extremely porous crystalline structure having tiny uniform pores, measuring in some species only a few Å, and endowing them with tremendous interior surface area having numerous ion exchangeable sites. Their negative charge enables these sites attract, adsorb, and eventually exchange, cations.
[0038] Consequently, aluminosilicates possess a unique ability to adsorb metallic activators of enzymes controlling biochemical processes in viruses, bacteria and some other low-organized organisms. Natural aluminosilicates, synthetic zeolites and other ion exchangers were tested in practicing and evaluating this invention.
[0039] Natural aluminosilicates or synthesized zeolites, when properly selected and modified, are, for all practical purposes, chemically inert and do not cause any chemical side effect to the host organism. They are not recognized by the pathogen or by the host as xenobiotics. Therefore, they are unlikely to trigger any immunologic reaction in the host or to activate any defense mechanism of the pathogen. Hence, the pathogens are unlikely to develop any resistance to the loss of enzyme activator, as in the practice of the present invention.
[0040] As therapeutics and prophylactics, aluminosilicates work in three principal ways, without any appreciable toxic or biochemical impact on the host organism:
[0041] a) inhibiting activity of microbial and neoplastic metalloenzymes;
[0042] (b) deactivating toxins; and
[0043] (c) adsorbing cations from immediate microenvironments, thus preventing microbes and neoplasms from utilizing them for replenishment or for production of new metalloenzymes.
[0044] (d) in synergic effect as microbial enzyme inhibitors and desiccants, they are extremely useful in dermatology for topical therapy of wet wounds, blisters, non-healing wounds, ulcers, eczemas, skin cancers, herpes blistering, etc.
[0045] Virgin aluminosilicates exhibit substantial differences in chemical composition, crystalline structure, density, and levels of impurities. Aluminosilicates of high density, aluminosilicates with a considerable crystalline silica contamination, fibrous aluminosilicates, and aluminosilicates contaminated with specific cations, and the like, are unsuitable for medical or pharmaceutical purposes. Accordingly, deionized, homoionized, selectively ion-recharged, or otherwise modified natural aluminosilicates and synthetic zeolites are preferable to virgin aluminosilicates in the practice of this invention.
[0000] 1. Typical Ion Exchangers Used in Experiments:
[0046] A. Natural zeolite: clinoptilolite, hydrated sodium potassium calcium aluminum silicate (Na, K, Ca)2O.Al 2 O 3 .10SiO 2 .8H 2 O), Winston, N.M. deposit, 4×6 size granules (approx. 5 mm).
[0047] Analysis (weight % for major oxides): Bowie and Barker, NM Bureau of Mines, 1986): Silicate 64.7%, CaO 3.3%, MnO 0.1%, Al 2 O 3 12.6%, MgO 1.0%, TiO 2 0.2%, K 2 0 3.3%, Fe 2 O 3 1.8%, and Na 2 0 0.9%.
[0048] Chemical Composition for given elements, by x-ray fluorescence (ppm, or wt. % noted; by Desborough, USGS OF Rpt 96-065 & 265, 1996.):
K 2.0% Cu 30 Zr 190 Nd 15 Ca 2.7% Fe 0.9% Rb 70 Nb 20 Ba 1030 Sr 1720 Ce 90 Pb 40
[0049] Cation Exchange Capacity:
[0000] 1.00-2.20 meq/g (may vary, as CEC values are relative to procedure and specific cations).
[0050] Major Exchangeable Cations: Rb, Li, K, Cs, NH4, Na, Ag, Ca, Cd, Pb, Zn, Ba, Sr, Cu, Hg, Mg, Fe, Co, Al, Cr, Mn, H.
[0000] (Selectivity of such cations is a function of hydrated molecular size and relative concentrations).
[0051] Purity:
[0052] Analysis by x-ray diffraction at the N. M. Institute of Mining and Technology and other tests suggest an 80% clinoptilolite content with the remaining material primarily inert volcanic ash and sediments. Clay and other mineral varieties are detectable only in minute quantities.
[0053] Physical Properties:
pH (natural) 8.0 (approx.) Acid Stability 0-7 pH Alkali Stability 7-13 pH Bulk Density (dried, −40 Mesh) 783-1054 kg/m 3 Cation Exchange Capacity (CEC) 1.0-2.2 meq/g Color White (85 optical reflectance) Crushing Strength 2500 lbs/in 3 (176 kg/m 3 ) Hardness 3.5-4.0 Mohs LA Wear (Abrasion index) 24 Mole Ratio 5.1 (SiO 2 /Al 2 O 3 ) Other non-soluble, non-slaking, free flowing Pore Size (diameter) 4.0 Å Pore Volume 52% (max.) Resistivity 9,000 (approx.) ohms/cm Specific Gravity 2.2-2.4 Surface Area 1357 yd 2 /oz (40 m 2 /g) Swelling index 0 Thermal Stability 1202° F. (650° C.)
[0054] B. Synthetic zeolite: Zeolyst® Y Type zeolite powder (FAU) CBV 400 in cation form.
Molecular Ratio 5.1 (SiO 2 /Al 2 O 3 ) Unit Cell Size 24.50 Å Surface area 730 m 2 /g
[0055] C. Bead Cellulose: Perloza® MT 50, a macroporous gel bead cellulose, stabilized by 25% ethanol.
Particle size 100-250 μm Temp. resistance (wet/pH 7.0/1 hr) 120° C. Stability within pH range 1-14 Stability in salt solutions with ionic strength up to 10 mol/l Chemical resistance aqueous solutions, buffer, organics, detergents, and chaotropic agents Swelling in aqueous solutions max 1 vol %
[0056] For purposes of this invention, the suitability of bead cellulose and its derivates is limited. They must withstand a wet stage, because the process of desiccation severely damages their porosity.
[0057] D. Anion exchanger: Anion Resin in Hydroxyl Form (A-S1P OH)
[0000] 2. Modification of Aluminosilicate Cation Exchangers:
[0058] A. H + Homoionization:
[0059] a. H + Homoionization Via Ammonia Decomposition:
[0060] The aluminosilicate is first impregnated by ammonium cations to displace the achievable maximum of other cations via ion exchange, then washed, dried, and finally heated to 500° C. At this temperature, ammonium decomposes to gaseous ammonia, which escapes, and hydrogen cations, which occupy available adsorption sites of the aluminosilicate. The thermal stability of treated aluminosilicate species and types must be considered unless a distortion of crystalline structure is negligible for the given application, or if a certain distortion of the crystalline structure is desirable as an additional functional modification.
[0061] b. H + Homoionization Via Electrolysis of Water:
[0062] A stream of hydrogen cations generated by electrolysis of water is directed through a bed, preferably a fluid bed, of sand or granule-sized aluminosilicate. Via ion exchange, an achievable maximum of other cations on ion exchangeable sites is replaced by hydrogen cations. The excess of hydrogen cations is reduced on the cathode to hydrogen gas. The cathode should be placed in a trapping device that collects reduction products and positively charged impurities. While this is an elegant and very pure method, an eventually insufficient concentration of electrolyte may render the H + homoionization imperfect. However, this is the only practical method of H + homoionization of hydrocolloid aluminosilicates.
[0063] The performance of the process may be improved by a modification of the electrolytic apparatus, provided by rotating chambers, by rotating phases of polarity, and/or by enhancing the electrolyte with ionized effluent water from one (or more) auxiliary electrolyzer(s). Such modified electrolytic apparatus also may be applied advantageously for ionization, homoionization, or reionization processes described later.
[0000] c. H + Homoionization Via Acid Treatment:
[0064] Most acids are suitable, but inorganic acids are preferable, especially nitric acid because of easy and environmentally sound disposal of NO 3 − anion effluent. However, for purposes of some special cation exchanger's selectivity, the use of organic acids must be considered. Adsorbent of sand or granule size is treated with diluted (e.g., 3%) acid in order to displace the achievable maximum of other cations by hydrogen cations via ion exchange, then rinsed with redistilled or medical grade deionized water to remove formed salts and anions to an achievable minimum.
[0065] Unless a synergic low pH effect is sought, the pH of H + homoionized adsorbents should be adjusted by washing with redistilled or medical grade deionized water, or by OH − treatment to establish the desirable pH value.
[0066] B. Deionization:
[0067] a. Partial:
[0068] The adsorbent is washed with redistilled or medical grade deionized water until most ion exchangeable sites are, by equilibration, free of cations. For achieving high degree of deionization, this method is too time consuming and economically unfeasible.
[0069] b. By Water Electrolysis:
[0070] A bed, preferably a fluid bed, of adsorbent is first electrolytically H + homoionized (method 2Ab), rinsed, and then the polarity of electrodes is reversed, whereby the aluminosilicate bed is exposed to a stream of hydroxyl anions (OH − ) until the desired pH is stabilized.
[0071] c. By a Combination Method:
[0072] A bed, preferably a fluid bed, of adsorbent, already H + homoionized (method 2Aa, 2Ac) is exposed to a stream of hydroxyl anions (OH − ) until the desired pH is stabilized.
[0073] d. By (OH − ) Effluent from an Anion Exchanger:
[0074] A bed, preferably a fluid bed, of H + homoionized adsorbent is exposed to an OH − water effluent generated by an anion exchanger until the achievable maximum of hydrogen cations has been removed from the aluminosilicate (or until a desired pH is established), via formation of water during the process of equilibration.
[0075] C. Selective Ionization:
[0076] For specific purposes (e.g., to prevent or to mitigate adsorption of selected cations, such as calcium or iron cations, or to deliver to the site cations for specific purposes (e.g., copper or cobalt ions), adsorbents may be ionized with any selected metal cation or cations via appropriate salts or hydroxides. A selective ionization may be implemented during or immediately after homoionization, or instead of homoionization. The following methods are preferred in the practice of this invention.
[0077] a. Selective Reionization by Cations Toxic to Microbes or Neoplastic Growth:
[0078] Using untreated (virgin) zeolite as a carrier of toxic cations to function at a destination site is known. However, for medical purposes the prior art is generally unsuitable because the concentration of such toxic cations in virgin aluminosilicate is difficult to establish and maintain because of uncontrollable factors, such as impurities, present unavoidable cations, pH fluctuation and consequent fluctuation of toxicity level, and equilibria in the microenvironment and within the aluminosilicate. In many applications accuracy in the cation concentration is critical. For example, excessive concentrations of copper cations will mitigate or completely inhibit production of mucous surfactant, which protects the host's gas-exchanging cells [4][5], and thereby may cause irreversible damage to a host's respiratory system and eventually result in death of the host. The methods of pretreatment of aluminosilicates as disclosed in this application, especially in applications of deionized aluminosilicates, allow appropriate accuracy of the dosage of toxic cations, thereby protecting the host's tissues, and equalizing any eventual site competition.
[0079] b. Selective Ionization of Adsorbent by Auxiliary Cations
[0080] This is of special interest. For example, one of the severe symptoms of inhalational anthrax is shortness of breath. It is caused (besides the bacterial damage to the alveolar epithelium) by the consumption of zinc ions by anthrax bacilli. Zinc cation is the primary activator of carbon anhydrase—the enzyme catalyzing the reversible hydration of CO 2 to H 2 CO 3 , a necessary reaction for facilitation of transport of CO 2 , and transfer and accumulation of H + and HCO 3 − . Hence, the deficiency of zinc cations contributes substantially to the inhibition of the respiratory gas exchange process. However, some carbon anhydrases are able to function with an alternative metal activator, as with the cobalt cation in this instance [19], and possibly with other metal cations, e.g., cadmium. Ion-exchanger adsorbing zinc activators from bacteria, from their immediate microenvironment, and from their toxins, can serve simultaneously as carriers of cobalt cations to boost the carbon anhydrase catalytic activity, and thereby greatly mitigate the “short breath” symptoms. The cobalt cations may be administered via an ion-exchangeable carrier, or as a part of a compound (e.g., salt or chelate) in any suitable therapeutic form (e.g., aerosol, hydrosol, intravenous infusion, or extracorporeal filtration of bodily fluids through a bed of cobalt-impregnated ionexchanger).
[0000] 3. Life Forms Used for Testing of Enzyme Inhibition; Experiments, Observations, and Evaluations:
[0081] A. Bacteria of the Bacillus anthracis Group:
[0082] Within the genus taxon, the current taxonomic and nomenclatural rules do not recognize any “group” taxon—which is only ancillary, indicating a close systematic and phylogenetic relation of certain species, here those of B. anthracis , namely: B. cereus, B. mycoides and B. thuringiensis . This group is frequently informally designated as the Bacillus cereus group. See, Genus Bacillus Cohn 1872. Hierarchy: Monera Bacteria-Inside series of Bacteria-Bacillales. Nomenclatorial/taxonomic status: Approved Lists Type species: B. subtilis Reference(s): Int. J. Syst. Bacteriol. 30:256 (AL), (Bergey's manual of determinative Bacteriology, 8th ed., 1974; Editors: Buchanan, R. E., Gibbons, N. E; Publisher: The Williams & Wilkins Co., Baltimore).
[0083] The B. anthracis group is a group of closely related species within the genus Bacillus . Though classified as valid different species, these organisms seem to differ only in the plasmids. All four species are large straight rod-shaped Gram-positive, non-flagellated, endospore-producing bacteria, whose spores do not swell the sporangium. They are often aerobic cells of 1-10 μm in length, and 1-1.5 μm in breadth, with a “jointed bamboo-rod” cellular appearance. All species of the B. anthracis group are pathogenic to humans, causing known or potential cutaneous/subcutaneous, intestinal, inhalational and other infectious conditions. The endospores are approximately 1 μm, species-indistinguishable within the group. Endospores are extremely resistant and may survive, for entire geological periods, at temperatures ranging from absolute zero to −40° C., and for decades between −30° C. and at least 50° C. They can withstand several minutes of usual autoclave sterilization and at least one minute of usual microwave sterilization. They germinate readily, and their vegetative cells grow on all ordinary laboratory media, at like temperatures and times, except that B. anthracis prefers a range closely about 37° C. Bacteria of the B. anthracis group share a multitude of other characteristics, including both biochemical and biophysical properties. Differentiation of the respective organisms is done in the vegetative form by determination of motility ( B. cereus rods are usually motile), and by the presence of toxin crystals ( B. thuringiensis ), and also by hemolytic activity ( B. cereus and B. thuringiensis are beta-hemolytic, B. anthracis is usually non-hemolytic), by growth requirement for thiamin, by lysis via gamma phage, by growth on chloral-hydrate agar, and further by the morphology of micro-colonies (e.g., a rhizoid growth is characteristic for B. mycoides , and a perloid growth pattern for B. anthracis ).
[0084] A. Bacillus anthracis (Cohn 1900), various synonyms: Bacillus cereus var. anthracis (Cohn 1872); Smith et al. 1946 ; Bacteridium anthracis (Cohn 1872); Hauduroy et al. 1953. Nomenclatorial/taxonomic status: Approved Lists Reference(s): Int. J. Syst. Bacteriol. 30:256 21 (AL), Ref.: Bergey's manual of determinative Bacteriology, 8th ed., 1974; Editors: Buchanan, R. 22 E., Gibbons, N. E; Publisher: The Williams & Wilkins Co., Baltimore); Risk group: 3 (German 23 classification) Type strain: ATCC 14578. Bacterial proteolytic enzyme: Zn + activated protease; 24 LF of the tripartite toxin: specific Zn ++ activated protease; OF: adenylate cyclase.
[0085] Bacillus anthracis is usually an aerobic, nonmotile species. The vegetative cells are large rods (1-8 μm long, 1-1.5 μm wide). B. anthracis is the causative agent of the anthrax disease. The symptoms of all three forms (cutaneous, intestinal, and inhalational) are well known [15]. Anthrax has been intended to be the most dangerous biological warfare agents for more than eighty years. Within that time, countless deadly strains have been developed, many of them as antibiotic-resistant and drug-resistant strains. Neither trials nor any cultivation of B. anthracis were conducted for purposes of this invention, but experimentation on other of the members of the group has been undertaken successfully and tentatively is believed to be applicable to every B. anthracis group member, based upon their close phylogenetic relationship.
[0086] B. Bacillus cereus (Frankland & Frankland 1887) ambiguous synonym(s): Bacillus cereus var. anthracis, Bacillus thuringiensis, Bacillus endorhythmos, Bacillus medusa . Nomenclatorial/taxonomic status: Approved Lists Reference(s): Int. J. Syst. Bacteriol. 30:256 (AL), (Ref: Bergey's manual of determinative Bacteriology, 8th ed., 1974; Editors: Buchanan, R. E., Gibbons, N. E; Publisher: The Williams & Wilkins Co., Baltimore); Risk group: 2 (German classification) Type strain: ATCC 14579, CCM 2010, NCm 9373, NCTC 2599. Bacterial proteolytic enzyme: Zn ++ activated protease; LF of the tripartite toxin: specific Zn activated protease; OF: adenylate cyclase. Intestinal infection, causing food poisoning, has been believed for a long time to be the only medical concern. The symptoms of the diarrhea type of food poisoning mimic those of Clostridium perfringens , beginning with watery diarrhea, sometimes accompanied by nausea and vomiting. Abdominal pain and cramps occur 6-15 hours after infection. Usually such symptoms persist for 24 hours. Symptoms of the emetic type are similar to those of Staphylococcus aureus : nausea and vomiting within 30 minutes to 6 hours after consumption of contaminated food. Abdominal cramps and diarrhea may occur too. Symptoms generally last less than 24 hours.
[0087] Recently, however, cutaneous B. cereus infections causing acute necrosis very similar to the cutaneous form of anthrax have been reported. Even more dangerously, several cases of B. cereus infections of other tissues occurred: including rapidly fatal meningoencephalitis [14], septicemia, mastitis, and several cases of potentially blinding endophthalmitis [6][7].
[0088] Since B. cereus is a typical airborne-spore proliferater, and sporulates and germinates easily, it is a potential agent for inhalation infections. No verified case of an inhalational form of infection has been reported yet. It may be hypothesized that B. cereus OF enzyme did not mutate yet—as B. anthracis did—to be effective enough to impair the host's defense system. Inocula: Bacillus cereus strain CBSC 15-4870/2001, freeze-dried CBSC 15-4870A/2001.
[0089] C. Bacillus mycoides (Fluegge 1886), ambiguous synonym: Bacillus mycoides corallinus. Hefferan 1904. Nomenclatural/taxonomic status: Approved Lists Reference(s): Int. J. Syst. Bacteriol. 30:257 (AL), (Ref.: Bergey's manual of determinative Bacteriology, eighth ed., 1974. Editors: Buchanan, R. E., Gibbons, N. E; Publisher: The Williams & Wilkins Co., Baltimore; Die Mikroorganismen, 3rd ed. vol. 2, 1896; Editor: Fliigge, C.; Publisher Vogel, Leipzig); Risk group: 1 (German classification); Type strain: ATCC 6A62. Bacillus mycoides is in almost all of its characteristics like B. cereus —but for its morphological rhizoid pattern of micro colonies. Bacterial proteolytic enzyme: Zn ++ activated protease; LF of tripartite toxin: specific Zn ++ activated protease; OF: adenylate cyclase. Inoculum: B. mycoides strain CBSC 15-4870/2001.
[0090] D. Bacillus thuringiensis (Berliner 191+5) ambiguous synonym: Bacillus cereus var. thuringiensis (Berliner 1915) ambiguous synonym: Bacillus cereus var, thuringiensis (Smith et al. 1952). Nomenclatural/taxonomic status: Approved Lists Reference(s): Int. J. Syst. Bacteriol. 30:258 (AL) (Ref.: Bergey's manual of determinative Bacteriology, 8th ed., 1974; Editors: Buchanan, R. E., Gibbons; N. E; Publisher: The Williams & Wilkins Co., Baltimore); Risk group: 1 (German classification); Type strain: ATCC 10792, Sp2000 Taxon Code: BIO-6867. Bacterial proteolytic enzyme: Zn ++ activated protease; LF of the toxin: specific Zn ++ activated protease; OF: adenylate cyclase.
[0091] B. thuringiensis is a bacterium, marketed worldwide as a specifically targeting bioinsecticide for control of plant pests (mainly caterpillars of the Lepidoptera), for control of mosquito larvae, simuliid blackflies, etc. Genetic material from B. thuringiensis toxin is used in the development of genetically engineered corn, cotton, and other crop plants. Most BT insecticides are derived from genetically improved mutations of B. thuringiensis biovar israelensis or B. thuringiensis kurstald. The active ingredients of marketed BT products are the bacterial dormant spores (>1012 per liter) and proteinaceous aggregates, including crystal-like parasporal inclusion bodies (PIB). The research done for manufacturers of BT products presents the bacterium as safe to human health. Yet, much as may be indicated, for example in DiPel®DF MSDS [16], the trials appear purpose-designed. In general, the health implications of exposures to B. thuringiensis , especially inhalational effects, have not been yet satisfactorily investigated.
[0092] Because of the close phylogenetic relation between B. anthracis group species, it should be taken into consideration that a dose of Bt spores, sufficiently potent to cause an inhalational Bt infection, may cause an infection with symptoms mimicking the symptoms of an anthrax infection (in at least one test, the mortality in guinea pigs was 10% [10]).
[0093] The BT products generate nonspecific cytotoxicities involving loss in bioreduction, cell rounding, blebbing and detachment, degradation of immuno-detectable proteins, and cytolysis. Some research data indicate that spore-containing BT products have an inherent capacity to lyse human cells in free and interactive forms and may also act as immune sanitizers [17]. Inocula used: Bacillus thuringiensis strain CBSC 15-4870/2001 (vegetative cells), CBSC 154870A/2001 (lyophilized vegetative cells), Javelin® (endospores, strain not identified), Thuricide® (endospores, strain not identified), and Skeetal® Abate (endospores, strain not identified).
[0094] Classified in the Bacillus anthracis group may be a newly described species Bacillus pseudomycoides but there has not yet been sufficient research done to validate it.
[0095] Bacillus pseudomycoides Nakamura 1998 Reference(s): BIO-6840, Nakamura (L.K.): Bacillus pseudomycoides sp. nov., Int. J. Syst. Bacteriol., 1998, 48, 1031-1035. No trial nor any cultivation of B. pseudomycoides has been conducted for the purposes of this invention. Many characteristics of B. anthracis, B. cereus, B. mycoides and B. thuringiensis are alike. For this invention the most important trait is that the bacterial metabolic protease and the lethal factor (LF) of the toxin are zinc-dependent; that is, the enzymes are activated by the zinc cation [8]][9][19][11][12][13]. Thus, it can be assumed with reasonable certainty that the mechanism of inhibition of their metabolic proteases and the deactivation of their toxin enzymes by adsorptive removal is similar in all four species, especially in B. cereus and B. anthracis , being so clearly alike in so many regards.
[0000] 4. Culture Media
[0096] A multitude of suitable media for culturing Gram + bacteria has been tried, including standard beef bouillon, nutrient gelatins and broths, count agar, modified nutrient agar (without peptone), protein-enriched nutrient agar, TSA w/5% and 10% sheep blood, etc. All of the media tested supported growth of vegetative cells and germination of endospores (where applied) along with the expected unimportant differences in morphological patterns of micro-colonies. After preliminary testing for suitable uniform media, a T-011 modified nutrient agar was chosen, consisting of standard beef extract, 5 g; agar, 15 g; with rehydration, 23 g/1000 ml. At its pH of 6.8, this agar is well within the optimal range for the Bacillus anthracis group.
[0000] 5. Inoculation of Bacteria
[0097] Many inoculation methods were tried in preliminary assays, including direct swab smear, diluted smears, loop inoculations in varied cell concentrations, smears and loops of inocula diluted in redistilled water, as well as smear and loop inocula diluted in physiol. solution. Dry inoculates of spores were tried also (where applicable). In all trials, the temperature was maintained at approx. 25° C. All of these experimental methods proved satisfactory. After these preliminary trials, two specific methods were selected for formal experimentation, as follows:
[0098] A: a swab smear inoculum from an established culture, diluted in redistilled water in a 1:10 approx. wt. ratio (cell:water). Cell count was not done. A long, single smear was applied.
[0099] B: 0.5 ml of diluted inoculum just described above (5A) was spot-dropped in the center. Note: Dry spore inoculation was abandoned in the final trials because the resulting rapidity of germination would have required needlessly difficult measurement of very small time intervals.
[0000] 6. Actual Experimental Results
[0100] The results in all trials proved positive, as expected in view of the preliminary trials. There were expected differences in vigor of the growths, in morphological patterns of micro-colonies, plus some aberrations from standard phenotype, but none pertinent to this invention. The following findings have been clearly established: A. the ionized zeolite inhibits Zn ++ activated bacterial proteases; and B. the inhibition is substantially instantaneous.
[0000] 7. Application of Aluminosilicate Enzyme Inhibitor
[0101] In some preliminary trials, the inhibitor was applied after a growth of micro-colonies was apparent under 10× magnification. This method was abandoned after it was well established that the inhibitor has an instant effect. Such instant effect is illustrated in FIG. 2 . Also in some trials with fluid media, a similar delay in inhibitor application was adopted.
[0102] A. For the inoculation method 5A, pH 6.4 stabilized deionized clinoptilolite particles of mesh 200 (<74 μm) were applied onto one half of the plate (the other half serves as a control) immediately after inoculation: a. as a dust, and b. as a hydrosol.
[0103] B. For inoculation method SA, pH 6.4 stabilized and deionized clinoptilolite particles of mesh 200 (<74 μm) were applied saturated in pieces of an inert porous absorptive material (filter paper) on the margin of the plate.
[0104] Note: In some preliminary runs, a bicomposite medium was also tried, by pouring one half of the plate in the original formulation, and the other half incorporating aluminosilicate inhibitor. Smearing inoculum over both halves of the plate, made the inhibitor effect immediately apparent.
[0105] The latter alternative also proved the tremendous adsorptive power of aluminosilicates to transfer ions through gel substances, as for example mucus, covering GEC's (gas-exchanging cells) in alveoli and elsewhere, or even more importantly, the protective coats of microbes.
[0000] 8. Detailed Description of Drawing Figures
[0106] FIG. 1 : Enzyme cofactors according to Holum
[0107] A complete enzyme (holoenzyme) consists of an apoenzyme (A) and one or more cofactors of the following three types: a, b, and c.
[0108] a. Coenzyme, a non-protein organic substance (e.g., a vitamin) which is dialyzable, thermostable, and loosely attached (single vertical connecting line) to the apoenzyme. It is a true substrate for enzyme-catalyzed reaction, and is recycled in a later step of a metabolic pathway by another enzyme.
[0109] b. Prosthetic group, a dialyzable and thermostable organic substance. It is more firmly attached (multiple linking vertical connecting lines) to the protein of the apoenzyme portion. Metal activator, a loosely attached metal cation, e.g., Zn ++ , K + , Fe ++ , Ca ++ , Mg ++ , Co ++ , Cu ++ , or Mn ++ . The metal cations are critical to the enzyme function, structure, and/or stability, and they ultimately are .of great biological and medical importance.
[0110] FIG. 2 : Adsorption of enzyme activator via zeolite (H + concentration ˜10 −7 )
[0111] Hydrogen cations (H + ) occupying some ion exchangeable sites (S) on the exosurfaces and endosurfaces of zeolite Z are in equilibrium with H + cations of the surrounding environment. When a bacterial digestive enzyme, a zinc-activated protease (DP), or a tripartite toxin (comprising zinc-dependent lethal factor LF, plus oedema factor OF (an adenyl cyclase), plus four-domain protein PA, enters the adsorptive range of such a zeolite particle, zinc cations Zn ++ will be adsorbed, immediately inhibiting the bacterium and deactivating the toxin. Also deactivated will be toxins already excreted by the pathogens into the host's macroenvironment (e.g., epithelium of alveoli, or bodily fluids.)
[0112] The drawing area designated Z represents only a minuscule part of the adsorptive surface of a zeolite particle, with interconnecting porous crystalline structure. The small size of most aluminosilicate pores (e.g., 4 Å, in the clinoptilolite example herein) precludes entry of pathogens or their proteins (e.g., bacterial digestive proteins, or toxins), whereupon rapid adsorption occurs on the outer surface, and (upon reaching equilibria there) thereafter proceeds within the particle of the ion exchanger.
[0000] 9. Mode of Inhibition
[0113] The negatively charged ion exchanger attracts and adsorbs the cation activators of enzymes [ FIG. 2 ] which renders the enzymes (the bacterial digesting protease and toxin's LF protease) deactivated.
[0000] 10. Practical Applications of Adsorbents:
[0114] In all applications, the ion adsorption is enhanced greatly in a wet environment. In a dry environment, e.g., on skin, inhibitor should be applied wet and be maintained wet (however, see 10.A.a.) For therapy of cutaneous and intestinal infections, the use of suitable aluminosilicates is entirely safe. For inhalational infection therapy, and in applications involving the circulatory system, a number of side effects of mechanical and biophysical nature should be considered.
[0115] A. Cutaneous infection and neoplasia: the adsorbent may be applied topically, as follows:
[0116] a. Dry: applicable in powder form directly to provide a synergic desiccating effect for wet or watery wounds, blisters, burns, herpes lesions, ulcers, bleeding wounds, etc.
[0117] b. Wet: for cutaneous infections and neoplasms not acutely wet, the adsorbent should be used preferably wet—mixed with clean water, preferably distilled water, and applied as a spray or a thin paste; incorporated in an inert gel; as a gel-like mixture with powdered hydrated layered clays, or in dressings or bandages impregnated with ion exchanging inhibitor.
[0000] B. Intestinal infection May be Treated, as Follows:
[0118] a. By ion adsorbent administered orally, preferably before a meal, mixed in a drink (water, milk, tea) devoid of any salt preservative. USDA approved addition of zeolite in feed is very conservative at 2%. A substantially higher dose (more than 5 times the approved rate) may cause a temporary depletion of intestinal flora. Particle size of the ion adsorbing inhibitor is not critical; 200 mesh (approx. 75 μm) being good. Of course, the smaller the particles are, the faster the adsorption process will be. Ion adsorbing inhibitor passing through the digestive system deactivates bacteria, viruses, protozoan, certain worms, toxins, and digestive metalloenzymes; then it is excreted.
[0119] b. Following ingestion, the adsorbent is at least partially H + homoionized by the stomach acid, and then gradually stabilized to the equilibrium in the small intestine.
[0120] C. Inhalational Infection
[0121] Preparation of dry aluminosilicates in the very small particle size (<3 μm) necessary to reach the inner epithelium of alveoli is technically difficult. The most practical mode of administration is inhalation of a mist containing submicron particles, easily calibratable by sedimentation in a water column. Insofar as there is a concern about clogging of alveoli, as caused by an eventual extremely large overdose, even a complete coverage of the alveolar epithelium by adsorbent's particles delivered via aerosol (or hydrosol) of suitable composition (e.g., containing surfactant) would not inhibit in appreciable extent the functioning of the epithelium. The adsorbent's capacity for CO 2 adsorption is negligible, in view of the huge volume of CO 2 exchanged in the lungs. However, unlike an a hydrosol, aluminosilicate dust in high concentrations, as in emergency use when water for appropriate preparation is not available, may temporarily desiccate the alveolar surface and hence may cause an extended need—expressed as coughing and temporary feeling of shortness of breath—for production of alveolar surfactant, as by type II cells. Even though only partial and temporary, such an administration process should be carefully monitored.
[0122] b. Except in utmost emergency, intravenous application should be avoided. Some specific concerns are obvious, such as deposition of adsorbent's particles in tissues. For an intravenous application, the particle size of the adsorbent in the injected solution should be <1 μm, preferably close to the particle size in the colloidal suspension. In order to prevent an eventual calcium deficiency shock, or iron deficiency in hemoglobin, and similar cation-dependent problems, the deionized adsorbents should be recharged with selected cations (e.g. calcium, iron, or magnesium cations).
[0123] c. In a hospital or similar setting, blood can be filtered (outside the body) through a bed of adsorbent. This method is important in a situation when the toxins in blood reach an otherwise uncontrollable concentration. The particle size should be between 200-500 μm to allow free flow of blood and an instant effect, and be pretreated as described above in b. to prevent any eventual cation adsorption problems.
[0124] Also, adsorbents may be selectively reionized by cation(s), which interfere with biochemical and biophysical processes in a pathogen (e.g., Ag + ) or, more specifically, interfere with production or maintenance of protective coats of pathogens (e.g., Cu ++ ).
[0000] 11. Prophylaxis
[0125] A. Dry and wet filters for gas masks, emergency homemade masks, mass transportation and building air filtration systems, etc.
[0126] B. Decontamination of skin and hair, clothing, homes and other enclosed or open areas
[0127] C. Decontamination of drinking water and food, especially fruit and vegetables.
[0000] 12. Other Bacteria Used:
[0128] Pseudomonas fluorescens, P. putida, Xanthomonas citri, B. brevi, Escherichia coli, Salmonella enteritidis, Citrobacter freundii, Enterobacter aerogenes, Enterococcus faecalis, Micrococcus luteus, Rhodospirillum rubrum , and Vibrio fisheri.
[0129] B. Viruses: All testing, experiments, observations, and evaluations of inhibition of viral enzymes were conducted in vivo, based on symptoms, under the generally accepted principle that viral metalloenzymes are practically the same in the molecular structure, and modus operandi of the metalloenzymes of higher life forms, especially bacteria.
[0130] Experiments upon Tobacco Mosaic Virus indicate that zeolites can be used as a universal viricide in agriculture (TMV affects almost 200 known genera of plants and causes serious damage in cultivated crops).
[0131] Primary leaves of twenty tomato seedlings were inoculated with TMV. Developed necrotic lesions were sprayed in parallel tests with a 10 g/liter water suspension (particles <75 μm) of virgin natural zeolites (chabazite and clinoptilolite), homoionized natural zeolites (chabazite and clinoptilolite), and synthetic Y, Beta, and ZMS-S zeolite powders. Spraying was repeated after 24 hours. With identical results in all tests, all lesions were dry within 2-3 days, and no new lesions developed in any of the treated plants. The tests also indicate a systemic effect of zeolites.
[0132] A suitable example is the apoenzyme of HIV protease, which is activated by zinc cations. It seems virtually impossible that a fundamental mutation would occur so as to enable the apoenzyme to be activated by some other source. If the ion changed, the same or other zeolites would be likely to adsorb it also.
[0133] In contrast, HIV protease inhibitors, such as saquinavir, ABT387, or ribavirin are known to be deactivated rapidly in the host by cytochrome P450 enzymes, so only a small fraction of the inhibitor encounters the virus. The host system has to “metabolize” most of the inhibitor drug, incurring severe side effects. To counter them, the protease inhibitor may be administered in combination with another drug, such as ritonavir, which suppresses cytochrome P450 enzymes, or steroids to prevent general immunologic overload It is highly desirable to identify inhibitors that operate directly upon viruses without likelihood of deactivation.
[0134] Notwithstanding that it is not known how the cytochrome enzymes identify the foreign chemicals, we can hypothesize with fair confidence that a zeolite, which does not react chemically and behaves—except for the adsorption—as an inert substance, will not be recognized by the cytochrome as xenobidtic and thus will not trigger any overload on the host's immune system. Too, the zeolite may be modified or synthesized in such a way that it cannot adsorb the specific metal cation of the cytochrome enzyme (an iron cation in P450), so no interference would likely occur.
[0135] Manifestations of herpes, such as so-called cold sores and fever blisters ( H. febrilis ), also yield to topical treatment. Phillipsite in the form of wetted powder ( — 75_m) eliminated such skin infection in a day or less. Furthermore, as an effective desiccant, zeolites quickly dry the sore area, speeding up the healing. Warts of viral origin (e.g., plantar warts) were eliminated likewise in a longer time—about 10-14 days—using wetted clinoptilolite powder incorporated in dressings, or adhesive bandages.
[0136] Severe symptoms of shingles (Herpes zoster) were eliminated within a week, healing within the next 14 days virtually without scarring. It is reasonable to assume ion adsorbents to have similar effects on other manifestations of viral infections, e.g., genital herpes, HPV, etc.
[0137] This rationale has been implemented successfully in upper respiratory infection symptomatically diagnosed as “common cold” generally considered being of viral origin. Liquid suspensions of zeolite particles in a range from 10 to 75 μm may be used as an inhalant to eliminate difficulty in breathing, and as a gargle to alleviate soreness of the throat. Concentrations of a few weight percent (e.g., 4%) are recommended for the aerosol, and somewhat higher (e.g., 10%) for the gargle.
[0138] C. In experiments with fungi (incl. yeasts), only the growth of Saccharomyces cerevisiae and Penicillium notatum was successfully inhibited by all tested species and forms of zeolites (inconclusive results were considered as negative). Virgin chabazite inhibited growth of Achlya spec., Saccharomyces cerevisiae, Penicillium notatum , and Candida kefyr (inconclusive results were considered as negative). Virgin phillipsite inhibited growth of Achlya spec., Saccharomyces cerevisiae , and Penicillium notatum . (inconclusive results were considered as negative). | Methods of preparing and using natural or synthetic zeolitic compositions therapeutically, so as to alleviate, cure, or even preclude human host disease attributable to exposure to bacteria within the Bacillus anthracis group: comprising, B. anthracis, B. cereus, B. Mycoide , and B. thurigiensis . Human exposure to the first member of the group causes the usually fatal disease, anthrax, in the absence of such effective pretreatment. | 1 |
FIELD OF THE INVENTION
This invention relates to stabilizing adjacent vertebrae of the spine, after surgery or trauma, while preserving a natural kinematic signature.
BACKGROUND OF THE INVENTION
Intervertebral devices are used to address diseases or disorders of the spine, or to address damage due to trauma. These devices operate, for example, to stabilize, guide, or limit movement of adjacent vertebrae, while bearing weight.
The spinal disc may be displaced or damaged due to trauma, disease, degenerative defects, or wear over an extended period. A disc herniation occurs when the annulus fibers are weakened or torn and the inner tissue of the nucleus becomes permanently bulged, distended, or extruded out of its normal, internal annulus confines. The mass of a herniated or “slipped” nucleus tissue can compress a spinal nerve, resulting in leg pain, loss of muscle control, or even paralysis. Alternatively, with discal degeneration, the nucleus loses its water binding ability and deflates, as though the air had been let out of a tire. Subsequently, the height of the nucleus decreases causing the annulus to buckle in areas where the laminated plies are loosely bonded. As these overlapping laminated plies of the annulus begin to buckle and separate, either circumferential or radial annular tears may occur, which may contribute to persistent or disabling back pain. Adjacent, ancillary spinal facet joints will also be forced into an overriding position, which may create additional back pain.
Whenever the nucleus tissue is herniated or removed by surgery, the disc space will narrow and may lose much of its normal stability. In many cases, to alleviate back pain from degenerated or herniated discs, the nucleus is removed and the two adjacent vertebrae are surgically fused together. While this treatment alleviates the pain, all discal motion is lost in the fused segment. Ultimately, this procedure places a greater stress on the discs adjacent to the fused segment as they compensate for lack of motion, perhaps leading to premature degeneration of those adjacent disc.
As an alternative to vertebral fusion, various prosthetic discs have been developed. The first prosthetics embodied a wide variety of ideas, such as ball bearings, springs, metal spikes and other perceived aids. These prosthetics are all made to replace the entire intervertebral disc space and are large and rigid. Many of the current designs for prosthetic discs are large and inflexible. In addition, prosthetic disc sizes and other parameters limit the approach a surgeon may take to implant the devices.
There is a need for a novel spinal disc that mimics the motion of the natural spinal disc.
SUMMARY OF THE INVENTION
An implant in accordance with the invention includes a flexible core, a first support component, operative to contact a first engaging surface of the core, and a second support component, operative to contact a second, opposing engaging surface of the core.
The implant of the invention is operative, when positioned between adjacent bones of a joint, such as adjacent vertebrae, to stabilize the joint. The implant further enables a natural kinematic movement of the joint, while limiting movement beyond a therapeutic range of motion.
A flexible core is provided with an inflection region of greater flexibility, which enables a displacement or changed orientation of opposed engaging surfaces of the core. In one embodiment, the core tapers at one end to form the inflection region, and which may deform or buckle to enable a relative angular displacement of engaging surfaces.
In addition, the core may compress to reduce a distance between portions of first and second engaging surfaces. Compression may include an expansion of material outwards relative to an interior of the core, or material of the core may collapse into an interior.
A tether, or lanyard may be provided, operative to limit a maximum displacement of the core and one or both of the first and second support components. The lanyard is affixed to two of either core and one or both support components. The lanyard is formed of a flexible material which does not prevent movement within an intended range of motion of the implant, and may advantageously be formed of a resilient material, to avoid an abrupt relative cessation of movement at a limit of travel.
Each support component includes an engagement plate having a core engaging surface and a bone engaging surface. A keel or other projection extends from the bone engaging surface, and is operative to engage a bony surface, for example, an interior portion of a vertebra. The projection may include a bone ingrowth surface, region, or spaces, to further secure the plate into engagement with the bone. Core engaging surfaces of the first and second support component are advantageously formed with a lubricious material relative to a surface material of the engaging surfaces of the core, if sliding or rotating relative to the core is intended.
In one embodiment, an inflection region of the core is most flexible at a point proximate an engaging surface. A hollow interior may be included, operative to provide a space into which material forming the inflection region may deflect. A core engaging surface is provided with a smooth surface, upon which a second engaging surface of the flexible core may slide.
Relative motion of bones, for example opposing bones of a joint, result from movement of a patient into which an implant of the invention is implanted. As the first and second support components are attached to these bones, a corresponding motion is induced in the support components. In the natural body of the patient, these bones move in accordance with six degrees of motion. Each of these degrees of motion are enabled with an implanted implant of the invention, as follows, with reference to FIG. 4 :
(1) translation in the direction indicated by line “X”, corresponding to the core sliding along an engaging surface;
(2) translation in the direction indicated by line “Y”, corresponding to axial compression of the core;
(3) translation in the direction indicated by line “Z”, corresponding to the core sliding along an engaging surface;
(4) rotation about an axis indicated by line “X”, corresponding to compression of one side of the core;
(5) rotation about an axis indicated by line “Y”, corresponding to the corerotating upon an engaging surface; and
(6) rotation about an axis indicated by line “Z”, corresponding to compression of one side of the core.
Alternatively stated, if an axis of the implant is defined as extending through an implant of the invention from a first adjacent bone to a second adjacent bone, the implant would enable relative motion of the first and second adjacent bones with respect to:
(a) opposite rotation about the axis;
(b) axially bending;
(c) axially compressing; and
(d) radial sliding with respect to the axis.
In an alternative embodiment, the core includes first and second segments separated by an inflection region that is substantially narrower than flanking segments, and thus bends to enable an angular displacement of the segments and their associated engaging surfaces.
In one embodiment of the invention, at least a portion of the support component has a core engaging surface configured as a curved smooth surface which slidably engages a mating region of the core. A curved slidable portion of the core engaging surface is recessed within a support component, and a mating slidable portion of an engaging surface projects from the core; alternatively, the core engaging surface may be projected, and an engaging surface of the core may be recessed.
Similarly, both sides of the core may be curved, each side mateable with a curved surface of a support component, for example, forming two convex surfaces. Mating surfaces on both sides of the core, for example, operate to foster a desired kinematic movement, and maintain a desired ligament tension throughout the expected range of motion. It should be understood, however, that in accordance with the invention, either surface may be either convex, concave, or flat, as the therapeutic needs of the patient dictate. In use, a configuration with a curved mating surface enables all six degrees of movement as described above, however, due to the mating curved slidable engaging surfaces, additional directional stability is provided.
In a further embodiment, the core is provided with a flat surface at a second engaging surface, which is matably connectable to a flat core engaging surface of a support component. One or more pins pass through pin bores or apertures provided in the core and support component, locking the two components together. In addition, a snap fit engagement between recessed and projecting portions of the core and a support component may be provided to further secure the core and support component together.
In yet another embodiment of the invention, the core engaging surface has a curved portion having a radius which is larger than a curved portion of a mating portion of the core. As such, the core may slide relative to the support component. The core may at the same time be rotated, and compressed evenly or laterally.
Mating surfaces of the core and a support component may include concave, convex, semi-spherical, or barrel shapes, whereby a resistance to sliding, spinning, rotating, rocking, or other relative movement may be uniform in all directions, or different in specific directions.
The invention provides a joint replacement implant, for example for replacement or stabilization of a cervical disc replacement, although other joints may be partially or completely replaced by the implant, for example one or more joints of the fingers, hand, wrist, elbow, shoulder, other areas of the spine, hip, knee, ankle, foot, or toes.
Implants of the invention are operative to restore the natural kinematic signature and natural joint properties, particularly for spinal discs, but for all joints which exhibit movement in all six degrees of motion, as detailed above.
All elements of implant may be made from a flexible material, although the core, in particular, flexes in order to accommodate an angular displacement of first and second support components. As the joint is flexed or extended, the flexible and or resilient material of the core may bulge or stretch to enable an angular displacement of opposing engaging surfaces. Additionally, or alternatively, an inflection region provides a relatively weaker region of the core, which is adapted through thickness and or shape to facilitate bending of the core.
Implant may be fabricated using any biocompatible and materials known to one skilled in the art, having sufficient strength, flexibility, resiliency, and durability for the patient, and for the term during which the device is to be implanted.
In accordance with the invention, a single implant may be used, to provide stabilization for a weakened joint or joint portion. Alternatively, two, three, or more implants may be used, at a single joint level, or in multiple joints. Moreover, implants of the invention may be combined with other stabilizing means.
Any surface or component of the invention may be coated with or impregnated with therapeutic agents, including bone growth, healing, antimicrobial, or drug materials, which may be released at a therapeutic rate, using methods known to those skilled in the art.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete understanding of the present invention, and the attendant advantages and features thereof, will be more readily understood by reference to the following detailed description when considered in conjunction with the accompanying drawings wherein:
FIG. 1 depicts a perspective view of an implant in accordance with the invention;
FIG. 2 illustrates a cross section of the implant of FIG. 1 , taken centrally through bone engaging projections of the implant;
FIG. 3 illustrates the implant of FIG. 1 , positioned between two adjacent bones in a body;
FIG. 4 illustrates the implant of FIG. 1 , with lines indicating degrees of motion of the implant;
FIG. 5 depicts a perspective exploded view of another embodiment of an implant of the invention;
FIG. 6 illustrates a cross section of the implant of FIG. 5 , taken centrally through bone engaging projections of the implant;
FIG. 7 depicts a perspective exploded view of a further embodiment of an implant of the invention; and,
FIG. 8 illustrates a cross section of the implant of FIG. 7 , taken centrally through bone engaging projections of the implant;
DETAILED DESCRIPTION OF THE INVENTION
In the description which follows, any reference to direction or orientation is intended primarily and solely for purposes of illustration and is not intended in any way as a limitation to the scope of the present invention. Also, the particular embodiments described herein are not to be considered as limiting of the present invention.
Referring now to the figures, in which like reference numerals refer to like elements, FIGS. 1 and 2 illustrate an implant 100 in accordance with the invention, including a flexible core 200 , a first support component 300 , operative to contact a first engaging surface 204 of core 200 , and a second support component 400 , operative to contact an opposing second engaging surface 208 of core 200 .
With reference to FIG. 3 , implant 100 is operative, when positioned between adjacent bones of a joint, such as for example vertebrae 10 , 12 , to stabilize a joint formed by adjacent vertebrae. Implant 100 further enables natural kinematic movement of the joint while limiting movement beyond a therapeutic range of motion. In one embodiment, this range of motion reflects the complete natural kinematic signature for the patient.
Referring again to FIGS. 1 and 2 , flexible core 200 includes a first engaging surface 204 disposed upon a first segment 202 , and a second engaging surface 208 , disposed upon a second segment 206 . In the embodiment shown in FIGS. 1 and 2 , flexible core 200 is provided with an inflection region 210 of greater flexibility, which enables a displacement or changed orientation of engaging surface 204 with respect to engaging surface 208 . In particular, first segment 202 tapers at one end to form inflection region 210 , which may deform or buckle to enable a relative angular displacement of engaging surfaces 204 , 208 .
In addition, core 200 may compress to reduce a distance between portions of first and second engaging surfaces 204 , 208 . Compression may include an expansion of material outwards relative to an interior 214 of core 200 , resulting in an increase in a diameter of core 200 , or material of core 200 may collapse into an interior of core 200 , thereby partially or completely maintaining an exterior dimension of core 200 . Alternatively, spaces within the material of core 200 may be reduced in size, for example spaces formed by a cellular or porous matrix of the material of core 200 may compress, whereby expansion of an exterior dimension of core 200 may be maintained or limited.
First support component 300 includes an engagement plate 302 having a core engaging surface 304 , and a bone engaging surface 306 . A keel or other projection 308 extends from bone engaging surface 306 , and is operative to engage a bony surface, for example, an interior portion of vertebra 10 or 12 . Projection 308 includes bone ingrowth spaces 310 , operative to provide an area for bone ingrowth, to further secure plate 302 into engagement with the bone to which plate 302 is attached.
Second support component 400 includes an engagement plate 402 having a core engaging surface 404 , and a bone engaging surface 406 . A keel, extension, or projection 408 extends from bone engaging surface 406 , and is operative to engage a bony surface, for example, an interior portion of vertebra 10 or 12 . Projection 408 includes bone ingrowth spaces 410 , operative to provide an area for bone ingrowth, to further secure plate 402 into engagement with the bone to which plate 402 is attached.
Bone ingrowth spaces 310 , 410 may each advantageously be formed at an angle with respect to a direction of projection 308 , 408 insertion, thereby potentially reducing an incidence of separation of implant 100 from the bone, after bone ingrowth has taken place.
Core engaging surfaces 304 , 404 of first and second support component 300 , 400 are advantageously formed with a lubricious material relative to a surface material of engaging surface 204 , 208 of core 200 , if sliding or rotating relative to core 200 is intended.
FIG. 2 additionally illustrates a tether, or lanyard 218 , operative to limit a maximum displacement of core 200 and one or both of first and second support components 300 , 400 . Lanyard 218 is affixed to two of either core 200 and one of support components 300 , 400 , or both support components 300 , 400 . Lanyard 218 is formed of a flexible material which does not prevent movement within an intended range of motion of implant 100 , as described herein, and may advantageously be formed of a resilient material, to avoid an abrupt relative cessation of movement, at a limit of travel, of elements to which it is affixed.
In the embodiment of FIGS. 1-4 , inflection region 210 is most flexible at a point proximate engaging surface 204 . A hollow interior 212 may be included, operative to provide a space into which material forming region 210 may deflect during displacement of engaging surface 204 relative to engaging surface 208 . A tether 218 may be provided, operative to limit a maximum extent of motion of first and second support components 300 , 400 . In this embodiment, core engaging surface 404 is provided with a smooth surface, upon which a second engaging surface of flexible core 200 may slide. Core engaging surface 404 is illustrated as substantially planar in FIG. 4 , although a projection and recess, as described for FIGS. 1 and 2 , may alternatively be provided. A lip or raised portion extending from core engaging surface 404 , not shown, may further, or in alternative to lanyard 218 , operate to limit an extent of movement of engaging surface 208 upon core engaging surface 404 .
With reference to FIGS. 3 and 4 , relative motion of bones 10 and 12 result from movement of a patient into which implant 100 is implanted. As first and second support components 300 , 400 are attached to bones 10 , 12 , respectively, a corresponding motion is induced in components 300 , 400 . It should be understood that, in accordance with the invention, component 400 may be connected to bone 10 , and component 300 may be connected to bone 12 ; that is, either component 300 or 400 may be positioned superiorly with respect to the other.
In the natural body of the patient, bones 10 and 12 move in accordance with six degrees of motion. Each of these degrees of motion is enabled with an implanted implant 100 , as diagrammed in FIG. 4 . Specifically:
(1) translation in the direction indicated by line “X”, corresponding to core 200 sliding along engaging surface 404 ;
(2) translation in the direction indicated by line “Y”, corresponding to axial compression of core 200 ;
(3) translation in the direction indicated by line “Z”, corresponding to core 200 sliding along engaging surface 404 ;
(4) rotation about an axis indicated by line “X”, corresponding to compression of one side of core 200 ;
(5) rotation about an axis indicated by line “Y”, corresponding to core 200 rotating upon engaging surface 404 ; and
(6) rotation about an axis indicated by line “Z”, corresponding to compression of one side of core 200 .
Alternatively stated, if an axis of the implant is defined as extending through an implant of the invention from a first adjacent bone to a second adjacent bone, the implant would enable relative motion of the first and second adjacent bones with respect to:
(a) opposite rotation about the axis;
(b) axially bending;
(c) axially compressing; and
(d) radial sliding with respect to the axis.
In an alternative embodiment, shown in FIGS. 5 and 6 , core 200 A includes first and second segments 202 A, 206 A, separated by an inflection region 210 A that is substantially narrower than flanking segments 202 A, 206 A, and thus bends to enable an angular displacement of segments 202 A, 206 A, and accordingly enables an angular relative displacement of engaging surfaces 204 A, 208 A.
FIG. 6 illustrates a cross-section of the implant 100 of FIG. 5 , taken through projections 308 and 408 . At least a portion of core engaging surface 404 A is configured as a curved smooth surface upon which a mating region of curved smooth surface of second engaging surface 208 A of flexible core 200 A may slide. In the illustration, a curved slidable portion of core engaging surface 404 A is recessed within second support component 400 A, and a mating slidable portion of engaging surface 208 A projects from core 200 A; however, it should be understood that engaging surface 404 A may be projected, and engaging surface 208 A may be recessed.
Similarly, a portion of first engaging surface 204 A is a curved smooth surface upon which a mating curved smooth surface of core engaging surface 306 A may slide. In the embodiment shown in FIGS. 5-6 , core 200 A forms two convex surfaces 204 A, 208 A, to foster a desired kinematic movement, and to maintain a desired ligament tension throughout the expected range of motion, and to promote a natural resting position of the bones. It should be understood, however, that in accordance with the invention, either surface 204 A or 208 A may be either convex or concave, as the therapeutic needs of the patient dictate. Alternatively, either surface may be flat, as illustrated in FIGS. 1-4 , discussed above, or FIGS. 7-8 , discussed below.
In one embodiment, a projection 312 extends from first engaging surface 306 A into core aperture or hollow interior 212 A, and is operative to limit an extent of movement of first support component 300 with respect to core 200 . A similar configuration could be provided for slidably mating engaging surfaces 404 A and 208 A.
Embodiments of the invention may be provided with one or more apertures 316 , 416 through which fasteners may be installed, to further secure implant 100 within a patient. For example, a bone screw may be passed through aperture 316 in first support component 300 and into bone 10 , and another bone screw may be passed through aperture 416 in second support component 400 , and into bone 12 . A bone growth agent may alternatively or additionally be provided within aperture 316 or 416 , or upon bone engaging surface 306 and or 406 , to promote bone growth thereinto. Bone growth surfaces may be provided with openings or texture into which tissue may grow and adhere.
In use, the embodiment of FIGS. 5-6 enables all six degrees of movement as described above, however, due to the mating curved slidable engaging surfaces 208 A and 404 A, additional directional stability is provided, whereby sliding is inhibited to an extent in the absence of flexion or extension of the joint. This inhibition arises from a natural gravitational resting state of the mating curved engaging surfaces 208 A and 404 A.
Referring now to the embodiment illustrated in FIGS. 7-8 , in which core 200 B is provided with a flat surface at second engaging surface 208 B, matably connectable to flat core engaging surface 404 B of second support component 400 . In this embodiment, core 200 B is configured to affix core 200 B with respect to rotation upon second engaging surface 404 B, by one or more pins 414 , which pass through one or more pin bores or apertures 216 , 416 , provided in core 200 B and second support component 400 B, respectively. While pins are illustrated, it should be understood that other fastener configuration are possible, including screws, adhesive, set screws, interference fit, press fit, or other methods as would be understood by one skilled in the art. Pins 414 may be threaded or press fit into apertures 216 or 416 , or secured using adhesive, and may be secured to either or both of core 200 B or second support component 400 B.
While pins 414 may be utilized to prevent rotation as well as to maintain core 200 B in a position upon engagement surface 404 B, an axial position of core 200 B against engagement surface 404 B may alternatively or additionally be maintained by a snap fit engagement between recessed portion 220 and projected portion 420 of core 200 B and core engaging surface 404 B, respectively. Alternatively, core 200 B may be provided with a projecting portion, and core engaging surface 404 B may be provided with a mating recess.
In any of the embodiments of the invention, should it be desired to maintain a position of either or both core engagement surfaces 304 , 304 A, 304 B and 404 , 404 A, 404 B relative to core 200 , 200 A, 200 B, pins, a snap fit, or other fasteners may be used, as described above.
With further reference to FIG. 8 , it can be seen that core engaging surface 304 B has a curved portion having a radius which is larger than a curved portion of first engaging surface 204 B. As such, core engaging surface 304 B and first engaging surface 204 B may readily slide, to a limited extent, relative to each other, as influenced by the difference between their respective curvatures. Core 200 B may also be rotated, and compressed evenly or laterally, as detailed elsewhere herein with respect to other embodiments of the invention.
It should be understood that superior and inferior positions of components, as illustrated, are for the convenience of the reader in understanding the invention, and that implant 100 may be implanted in a reverse orientation than is shown, as benefits the patient.
In use, the embodiment of FIGS. 7-8 enables all six degrees of movement as described above, however, due to the mating curved slidable engaging surfaces 204 B and 304 B, additional directional stability is provided, whereby sliding is inhibited to an extent in the absence of flexion or extension of the joint. This inhibition arises from a natural gravitational resting state of the mating curved engaging surfaces 204 B and 304 B. Rotation, or spinning, of bone 10 with respect to bone 12 , is translated only through an interface between first engaging surface 204 B and core engaging surface 304 B, as second engaging surface 208 B is affixed with respect to core engaging surface 404 B. Similarly, sliding is carried out solely through this interface, for the same reasons. Surfaces 208 B and 404 B may alternatively slide with respect to each other, as detailed herein with respect to other embodiments.
Mating surfaces 204 , 204 A, 204 B and 304 , 304 A, 304 B; or 208 , 208 A, 208 B and 404 , 404 A, 404 B, may, for example, be concave, convex, semi-spherical, elliptical, complex, or barrel shaped, whereby a resistance to sliding, spinning, rotating, rocking, or other relative movement may be uniform in all directions, or different in specific directions.
FIG. 8 further illustrates insertion tool channels, bores, openings, or apertures 218 , 418 , in first and second support components 300 B, 400 B. As implant 100 is inserted between joint surfaces maintained in spaced relation by ligaments, it may be necessary to mechanically compress implant 100 prior to insertion within the joint. A tool, not shown, such as is known in the art, may be provided with tines which engage tool apertures 218 , 418 , whereupon first and second support components 300 B, 400 B may be moved together, or apart, as determined by the practitioner, during implantation. Further, implant 100 may be implanted through an anterior, anterolateral, or lateral approach, and accordingly, tool apertures 218 , 418 provide a means for mechanically grasping and manipulating implant 100 during implantation.
The invention provides a joint replacement implant, for example for replacement or stabilization of a cervical disc replacement, although other joints may be partially or completely replaced by implant 100 , for example one or more joints of the fingers, hand, wrist, elbow, shoulder, other areas of the spine, hip, knee, ankle, foot, or toes.
Implant 100 is operative to restore the natural kinematic signature and natural joint properties, particularly for spinal discs, but for all joints which exhibit movement in all six degrees of motion, as detailed above.
All elements of implant 100 may be made from a flexible material, although core 200 , in particular, flexes in order to accommodate an angular displacement of first and second support components 300 , 400 . As the joint is flexed or extended, the flexible and or resilient material of core 200 may bulge or stretch to enable an angular displacement of first and second engaging surfaces 204 , 208 . Additionally, or alternatively, inflection region 210 provides a relatively weaker region of core 200 which is adapted through thickness and or shape to facilitate bending of core 200 .
Implant 100 may be fabricated using any biocompatible materials known to one skilled in the art, having sufficient strength, flexibility, resiliency, and durability for the patient, and for the term during which the device is to be implanted. Examples include but are not limited to metal, such as, for example titanium and chromium alloys; polymers, including for example, PEEK or high molecular weight polyethylene (HMWPE); and ceramics.
Portions or all of the implant may be radiopaque or radiolucent, or materials having such properties may be added or incorporated into the implant to improve imaging of the device during and after implantation.
Opposing mating surfaces which rotate, spin, or slide, including core engaging surfaces 304 , 304 A, 304 B, 404 , 404 A, 404 B, and first and second engaging surfaces 204 , 204 A, 204 B and 208 , 208 A, 208 B, may be made of the same or different materials, which combination produces a therapeutic fluidity of motion, or desired drag. Surfaces of implant 100 may be plasma sprayed, for example by titanium plasma spray, and may be bead blasted or electropolished.
More particularly, The support components may be manufactured from cobalt-chrome-molybdenum alloy, Co—Cr—Mo, as specified in ASTM F1537 (and ISO 5832-12). The smooth surfaces may be plasma sprayed with commercially pure titanium, as specified in ASTM F1580, F1978, F1147 and C-633 (and ISO 5832-2). The core may be manufactured from ultra-high molecular weight polyethylene, UHMWPE, as specified in ASTM F648 (and ISO 5834-2).
Core 200 , 200 A, 200 B, may alternatively, in one embodiment, be fabricated using polycarbonate urethane (PCU), or a thermoplastic polycarbonate urethane (TPU) such as Bionate, a registered trademark of DSM IP Assets B.V. Corporation, of Heerlen Netherlands, for a thermoplastic elastomer formed as the reaction product of a hydroxyl terminated polycarbonate, an aromatic diisocyanate, and a low molecular weight glycol used as a chain extender. Other polymeric materials with suitable flexibility, durability, and biocompatibility may also be used, as understood by one skilled in the art.
In accordance with the invention, implants of various sizes may be provided to best fit the anatomy of the patient. Support components and a core of matching or divergent sizes may be assembled during the implantation procedure by a medical practitioner as best meets the therapeutic needs of the patient, the assembly inserted within the body using an insertion tool. Implants of the invention may also be provided with an overall angular geometry, for example angular mating dispositions of support components and core, to provide for a natural lordosis, or a corrective lordosis, for example of from 0° to 6° for a cervical application, although much different values may be advantageous for other joints. Implant heights, for use in the cervical vertebrae for example, may typically range from 7 mm to 12 mm, although the size is dependent on the patient, and the joint into which an implant of the invention is to be implanted.
In accordance with the invention, a single implant 100 may be used, to provide stabilization for a weakened joint or joint portion. Alternatively, two, three, or more implants 100 may be used, at a single joint level, or in multiple joints. Moreover, implants 100 may be combined with other stabilizing means.
Additionally, implant 100 may be fabricated using material that biodegrades in the body during a therapeutically advantageous time interval. Further, implant 100 is advantageously provided with smooth and or rounded exterior surfaces, which reduce a potential for deleterious mechanical effects on neighboring tissues.
Any surface or component of the invention may be coated with or impregnated with therapeutic agents, including bone growth, healing, antimicrobial, or drug materials, which may be released at a therapeutic rate, using methods known to those skilled in the art.
It will be appreciated by persons skilled in the art that the present invention is not limited to what has been particularly shown and described herein above. In addition, unless mention was made above to the contrary, it should be noted that all of the accompanying drawings are not to scale. A variety of modifications and variations are possible in light of the above teachings without departing from the scope and spirit of the invention.
All references cited herein are expressly incorporated by reference in their entirety. In addition, unless mention was made above to the contrary, it should be noted that all of the accompanying drawings are not to scale. There are many different features to the present invention and it is contemplated that these features may be used together or separately. Thus, the invention should not be limited to any particular combination of features or to a particular application of the invention. Further, it should be understood that variations and modifications within the spirit and scope of the invention might occur to those skilled in the art to which the invention pertains. Accordingly, all expedient modifications readily attainable by one versed in the art from the disclosure set forth herein that are within the scope and spirit of the present invention are to be included as further embodiments of the present invention. | An implant stabilizes two adjacent bones of a joint, while enabling a natural kinematic relative movement of the bones. Support components are connected to each bone of the joint, and a flexible core is interposed between them. The core and at least one of the support components are provided with a smooth sliding surface upon which the core and support component may slide relative to each other, enabling a corresponding movement of the bones. The surfaces may have a mating curvature, to mimic a natural movement of the joint. The core is resilient, and may bend or compress, enabling the bones to move towards each other, and or to bend relative to each other. | 0 |
RELATED APPLICATIONS
This application claims priority to U.S. Provisional Application No. 61/336,832 filed on Jan. 27, 2010, the entire contents of which are hereby incorporated herein by reference.
TECHNICAL FIELD
The present disclosure relates generally to devices used to retrieve or manipulate items or structures located in anatomically remote locations, such as items located in body lumens. More specifically, the present disclosure relates to snare devices and methods for their use.
BRIEF DESCRIPTION OF THE DRAWINGS
The embodiments disclosed herein will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. These drawings depict only typical embodiments, which will be described with additional specificity and detail through use of the accompanying drawings in which:
FIG. 1 is a side view of a delivery conduit having a single lumen.
FIG. 1A is a cross sectional view taken through lines 1 A- 1 A of the delivery conduit of FIG. 1 .
FIG. 2 is a side view of a snare device with two loops.
FIG. 2A is a side view of the snare device of FIG. 2 , with a bend placed in the shaft of the device.
FIG. 3 is a side view of a snare device having with a loop at each end of the shaft portion and multiple bends in the shaft portion.
FIG. 3A is a cross sectional view taken through lines 3 A- 3 A of the snare loop shown in FIG. 3 .
FIG. 4 is a side view of a snare device with two loops, each loop having a rectangular profile, and a shaft portion with a single angular bend.
FIG. 4A is a cross sectional view taken through lines 4 A- 4 A of the snare loop shown in FIG. 4 .
FIG. 5 is a side view of a snare device with a trapezoidal loop at one end of the shaft, a circular loop at another end of the shaft, and a single angular bend in the shaft.
FIG. 5A is a cross sectional view taken through lines 5 A- 5 A of the snare loop shown in FIG. 5 .
FIG. 6 is a side view of a snare device with an elliptical loop at one end of the shaft, a rectangular loop at another end of the shaft, and a shaft with multiple bends.
FIG. 6A is a cross sectional view taken through lines 6 A- 6 A of the snare loop shown in FIG. 6 .
FIG. 7A is a side view of an embodiment of a snare device with a delivery conduit and a guidewire.
FIG. 7B is a side view of the snare device of FIG. 7A with the snare loop extended from the delivery conduit.
FIG. 7C is a side view of the snare device of FIGS. 7A and 7B with the snare loop extended from the delivery conduit and surrounding a fragment.
FIG. 7D is side view of the snare device of FIGS. 7A , 7 B, and 7 C with the snare loop drawn partially into the lumen such that the fragment is trapped between the loop and the delivery conduit.
FIG. 8A is a side view of a snare device having a delivery conduit with two lumens.
FIG. 8B is a cross sectional view of the delivery conduit taken through lines 8 B- 8 B.
FIG. 8C is a cross sectional view of another embodiment of a delivery conduit with two lumens.
FIG. 8D is a cross sectional view of yet another embodiment of a delivery conduit with two lumens.
DETAILED DESCRIPTION
A snare device may be configured to allow a practitioner to change the shape of the snare device during a therapeutic procedure. Such a device may allow a practitioner to more precisely position the device with respect to the object to be retrieved and the surrounding body lumen. Precise positioning of a snare device may enable a practitioner to more quickly and efficiently perform the needed therapy. Further, precise positioning may lessen trauma at the therapy site, minimizing injury from unwanted contact between the snare and portions of the body lumen. For example, precise positioning of the snare loop may reduce the possibility that the snare loop will rotate (or “whip”) during therapy, which rotation can damage the inner lining of blood vessels.
It will be readily understood that the components of the embodiments as generally described and illustrated in the Figures herein could be arranged and designed in a wide variety of different configurations. Thus, the following more detailed description of various embodiments, as represented in the Figures, is not intended to limit the scope of the disclosure, but is merely representative of various embodiments. While the various aspects of the embodiments are presented in drawings, the drawings are not necessarily drawn to scale unless specifically indicated.
The phrases “connected to,” “coupled to,” and “in communication with” refer to any form of interaction between two or more entities, including mechanical, electrical, magnetic, electromagnetic, fluid, and thermal interaction. Two components may be coupled to each other even though they are not in direct contact with each other. For example, two components may be coupled to each other through an intermediate component.
The directional terms “distal” and “proximal” are given their ordinary meaning in the art. That is, the distal end of a medical device means the end of the device furthest from the practitioner during use. The proximal end refers to the opposite end, or the end nearest the practitioner during use.
“Delivery conduit,” as used herein, refers to an artificial channel capable of establishing communication between a remote location and an external environment. For example, in certain embodiments described herein, the delivery conduit comprises the outer sheath of a snare device, which in some embodiments comprises a catheter.
A used herein “fragment” means either a foreign object disposed within a body lumen or an anatomical structure within the body which requires ligation or removal.
Further, as used herein, a “snare device” refers to a medical device with an elongate shape having at least one “snare loop.” Thus, a snare device may or may not include a delivery conduit or outer sheath member. As used herein a “snare loop” refers to a closed shape configuration of an elongate member such as a wire. The term is not limited to “loops” with generally circular shapes, but includes any variety of shapes, including, for example, square loops, rectangular loops, ellipsoidal loops, trapezoidal loops, etc.
Finally, as used herein, the term “shapeable” refers to a component that retains approximately at least 25% of its shape when it is (1) plastically deformed or shaped, (2) coupled with a second component which tends to deform the first component from its shaped state (such as to its original shape), and (3) removed from the second component. For example, a shaft which is initially substantially straight, deformed with an angular bend, then placed in a sheath which tends to hold the shaft in a straight position is “shapeable” if the shaft retains approximately at least 25% of the angle of the deformation when it is removed from the sheath. Similarly, the term “shaped” refers to components that are pre-shaped, which tend to retain their shape and cannot be readily plastically deformed. For example, a snare loop formed from a memory alloy with a given shape which is placed in a sheath which constrains that shape may be said to be “shaped” if the snare loop returns to its original shape when removed from the sheath.
Referring now to FIG. 1 which is a side view of a delivery conduit 12 having a single lumen 13 . In the illustrated embodiment, the lumen 13 extends the length of the delivery conduit 12 , from the proximal end 18 of the delivery conduit 12 to the distal end 16 of the delivery conduit 12 . As also shown in FIG. 1A , the delivery conduit 12 and the lumen 13 may define a side wall 15 of the delivery conduit. The side wall 15 may be defined as the portion of the delivery conduit 12 surrounding the lumen where the outer surface of the side wall runs generally parallel to the longitudinal axis of the delivery conduit 12 . In some embodiments, the delivery conduit may have a side port 14 , or an opening in the side wall 15 of the delivery conduit 12 .
In certain embodiments the delivery conduit 12 may also be configured with a connector 19 to couple the delivery conduit 12 to another device. This connector 19 may be any type of connector known in the art, for example a Luer connector.
In the illustrated embodiment the side port 14 extends through the side wall 15 of the delivery conduit 12 allowing access from the lumen 13 to an area outside the delivery conduit 12 . In one embodiment the side port 14 constitutes a removed area of from about 5% to about 48% of the circumference of the side wall 15 of the delivery conduit. In other embodiments the side port 14 may fall into a smaller range of values, for example from about 25% to about 48% of the circumference of the delivery conduit.
In some embodiments the distal end 16 of the delivery conduit 12 may be open, creating an end port, or distal opening in the distal tip of the delivery conduit 12 . In such embodiments, the lumen 13 extends through the end of the delivery conduit 12 at the distal end 16 . It other embodiments the lumen 13 may not extend through the distal end 16 of the delivery conduit 12 . It will be appreciated that in some embodiments the delivery conduit 12 will have such an opening at the distal end 16 in addition to a side port 14 , whereas in other embodiments the delivery conduit 12 will only have a side port 14 with no opening at the distal end 16 . In still further embodiments the delivery conduit will only have an opening at the distal end 16 and have no side port 14 .
In embodiments where the delivery conduit 12 has an opening at the distal end 16 , the opening may be configured to allow a guidewire (not shown) or other elongate medical device to extend through the distal end of the delivery conduit 12 . In one embodiment the delivery conduit 12 may be configured such that the lumen 13 is sized to accommodate both a guidewire and the shaft of a snare device. In one example of such an embodiment, the guidewire may be configured to extend through an opening in the distal end 16 of the delivery conduit 12 and the snare device configured to extend through a side port 14 . In other embodiments, both a guidewire and a snare device may extend through the same opening.
In certain embodiments the delivery conduit 12 defines an outer sheath through which medical devices (for example guidewires or snare devices) may pass during therapy. It will be appreciated that medical devices disposed within the delivery conduit 12 may be configured to be longitudinally displaceable with respect to the delivery conduit 12 during use.
The delivery conduit 12 may be made from any extrudable, medical grade plastic such as those commonly used for making catheters. Examples include but are not limited to polyurethane, polyethylene (varying densities), PET (polyethylene terephthalate), PVC, polypropylene, nylon, peba byx, ABS, Hytrel®, Santoprene®, polycarbonate, Kraton®, PES, PVDF, and FEP. The extruded plastic may be cut to length, followed by creation of the side opening 14 by conventional cutting or machining methods known in the art.
FIGS. 2-6 are side views of snare devices comprising shafts and snare loops. It will be appreciated that the illustrated embodiments have analogous features. The disclosure recited in connection with any embodiment may be applicable to any analogous feature in another embodiment, whether or not the components are numbered in both embodiments. Further, it will be appreciated that any of the snare devices illustrated or described in connection with any of FIGS. 2-6 may be used in any combination with any of the embodiments of delivery conduits disclosed in connection with FIGS. 1 and 1A . FIGS. 2A , 3 A, 4 A, 5 A, and 6 A are cross sectional views of the corresponding snare devices, but it will be appreciated that any of the disclosure or features recited in connection with any of these embodiments may analogously apply to every other embodiment or combination.
FIG. 2 is a side view of an embodiment of a snare device 20 comprising a first snare loop 24 attached to one end of a shaft 22 and a second snare loop 26 attached to an opposite end of the shaft 22 . In this embodiment both the first snare loop 24 and the second snare loop 26 are configured to be in a generally circular configuration. In some embodiments the snare loops 24 , 26 may be shaped. In other words, the circular configuration of the first snare loop 24 and the second snare loop 26 may be retained by constructing the first snare loop 24 and the second snare loop 26 of a superelastic material (such as a nickel titanium alloy, for example, nitinol). Superelastic materials may be able to be deformed to a much greater degree than ordinary materials without taking a permanent kink. It will be appreciated that in some embodiments only one of the two loops may be formed of a superelastic material, both loops may be so formed, or neither loop may be formed of a superelastic material.
In the embodiment illustrated in FIG. 2 , the first snare loop 24 and the second snare loop 26 are configured to be of differing sizes. When utilizing such embodiments, a physician may discover during the procedure one size of snare loop 24 , 26 may be preferred or required. Accordingly, in certain embodiments the physician can insert the snare device into a body lumen in such a manner as to utilize the desired snare loop 24 , 26 .
FIG. 2A is a side view of the snare device 20 shown in FIG. 2 , wherein the shaft 22 has been configured to have a bend 28 along its length. In certain embodiments, the shaft 22 may be shapeable, that is, made of a material such as stainless steel which allows a permanent deformation to be placed in it prior to or during the procedure as determined by the physician.
FIG. 3 is a side view of another embodiment of a snare device 30 which has a shaft 34 configured with an angular bend 36 and an additional composite bend 38 . In some embodiments bends 36 , 38 will be formed during therapy and shaped according to an individual physician's preference. The shaft 34 may be made of a material such as stainless steel which allows a permanent deformation to be placed in it prior to or during the procedure as determined by the physician. As illustrated in FIG. 3 , a first snare loop 32 having an elliptical configuration may be attached to one end of the shaft 34 and a second snare loop 33 having a circular configuration may be attached to an opposite end of the shaft 34 . The elliptical configuration of the first snare loop 32 and the second snare loop 33 may be retained by constructing the first snare loop 32 and the second snare loop 33 of a of a superelastic material (such as a nickel titanium alloy, for example, nitinol).
FIG. 4 is a side view of an embodiment of a snare device 40 which has a shaft 44 configured with an angular bend 46 . The shaft 44 may be made of a material such as stainless steel which allows a permanent deformation to be placed in it prior to or during the procedure as determined by the physician. In the illustrated embodiment, a first snare loop 42 having a rectangular configuration is attached to one end of the shaft 44 and a second snare loop 43 having a smaller rectangular configuration is attached to an opposite end of the shaft 44 . The rectangular configuration of the first snare loop 42 and the second snare loop 43 may be retained by constructing the first snare loop 42 and the second snare loop 43 of a superelastic material.
FIG. 5 is a side view of yet another embodiment of a snare device 50 having a first snare loop 52 shaped into a trapezoidal configuration and a shaft 54 shaped to have a single, angular, bend 56 . A second snare loop 53 in a circular configuration is attached to an opposite end of the shaft 54 . The trapezoidal configuration of the first snare loop 52 and the circular configuration of the second snare loop 53 may be retained by constructing the first snare loop 52 and the second snare loop 53 of a superelastic material. The shaft 54 may be made of a material such as stainless steel which allows a permanent deformation to be placed in it prior to or during the procedure as determined by the physician.
FIG. 6 is a side view of an embodiment of a snare device 60 having a first snare loop 62 shaped into an elliptical configuration and a shaft 64 shaped to have a first angular bend 66 , second angular bend 68 and a second snare loop 63 having a rectangular configuration. It is noted that, in this embodiment, the second snare loop 63 is smaller in dimension than the first snare loop 62 . The elliptical configuration of the first snare loop 62 and the rectangular configuration of the second snare loop 63 may be retained by constructing the first snare loop 62 and the second snare loop 63 of a superelastic material. The shaft 64 may be made of a material such as stainless steel which allows a permanent deformation to be placed in it prior to or during the procedure as determined by the physician.
It will be understood that the specific configurations shown in FIGS. 2-6 are illustrative only and that many possible shapes and configurations are possible. For example, any size or shape of snare loop described above may be used in any combination with any other size or shape of snare loop disclosed or any shape or configuration of shaft disclosed. Further, the particular shapes, sizes, and configurations are illustrative only; it is within the scope of the current disclosure to modify these shapes and sizes in a manner known in the art.
In some embodiments, the shafts 22 , 34 , 44 , 54 , 64 as seen in FIGS. 2-6 are shipped in an unshaped configuration and may also be used without a physician shaping the shaft during the procedure.
As depicted in FIGS. 3A , 4 A, 5 A, and 6 A, the snare loops 24 , 26 , 32 , 33 , 42 , 43 , 52 , 53 , 62 , 63 may be radiopaque in nature. FIGS. 3A , 4 A, 5 A, 6 A are cross sectional views taken through the snare loops 32 , 42 , 52 , 62 and show a radiopaque coating 95 which surrounds the core wire 97 . Though not shown in the figures, it will be understood that the snare loops 24 , 26 , 32 , 33 , 42 , 43 , 52 , 53 , 62 , 63 may also be radiopaque in some embodiments. Radiopacity may be imparted to the snare loops by processes known to those having skill in the art, including but not limited to dipping, coating, plating, vapor deposition, coils, coverings, and sleeves. Exemplary radiopaque materials include platinum, and gold plated tungsten. In one embodiment only the snare loops 24 , 26 , 32 , 33 , 42 , 43 , 52 , 53 , 62 , 63 are radiopaque, while in other embodiments (not shown) the radiopaque coating 95 may extend proximally further down the shafts 22 , 34 , 44 , 54 , 64 .
The snare devices 20 , 30 , 40 , 50 , 60 may be made by obtaining a shapeable wire of a thickness (in some embodiments between about 0.014-0.018 inches) suitable to maintain a bend, for the shaft portions 22 , 34 , 44 , 54 , 64 , followed by cutting the wire to length. Suitable shaft materials include but are not limited to 304 stainless steel and 316 stainless steel, and could also include any non-superelastic material able to be quickly and easily shaped. In one embodiment, the snare loop 24 , 26 , 32 , 33 , 42 , 43 , 52 , 53 , 62 , 63 is attached to a more proximal point of the shaft wire and attached by conventional attachment methods known in the art, including but not limited to welding, adhesives, ball-and-socket techniques, cinching mechanisms, and mechanical fasteners. When completed, the joined area (not shown) may be substantially flush with the wire so as to minimize the occurrence of rough or inequitable areas that could cause tissue damage upon deployment.
Radiopacity may be imparted to the snare loops 24 , 26 , 32 , 33 , 42 , 43 , 52 , 53 , 62 , 63 by applying a radiopaque coating 95 by conventional methods as discussed above. Following curing of the radiopaque coating 95 the snare wire 20 , 30 , 40 , 50 , 60 may be sterilized and loaded into a delivery conduit 12 with the proximal end being inserted through the proximal opening 18 .
FIGS. 7A-8D illustrate embodiments of snare devices where shaft members such as those disclosed in connection with FIGS. 2-6 and 2 A- 6 A are coupled to a delivery conduit such as that described in connection with FIGS. 1 and 1A .
FIGS. 7A-7D illustrate a snare device 10 comprising a single lumen 13 with a snare shaft 22 and a guidewire 90 disposed within the lumen 13 . In the illustrated embodiment the delivery conduit 12 is configured with a side port 14 and an opening at the distal end of the delivery conduit. The guidewire is configured to extend through the opening in the distal end of the delivery conduit 12 and the snare loop and shaft configured to extend through the side port 14 . FIGS. 7A-7D illustrate a single lumen delivery conduit 12 in multiple stages of deployment, including trapping a fragment F.
FIGS. 8A-8D illustrate embodiments of a snare device 10 with two lumens 13 A, 13 B. FIG. 8A illustrates a snare device 10 comprising a delivery conduit 12 with two lumens 13 A, 13 B, a snare shaft 22 and loop 24 , and a guidewire 90 . In the illustrated embodiment, the snare shaft 22 is disposed within lumen 13 A and the guidewire within lumen 13 B. As illustrated, lumen 13 A may have a side port 14 configured to allow communication between lumen 13 A and an area outside the delivery conduit 12 . In addition to side port 14 , lumen 13 A may also be configured with an opening at the distal end of the delivery conduit 12 . Similarly, lumen 13 A could include an opening at the distal end of the delivery conduit without a side port 14 . In the illustrated embodiment, lumen 13 B is configured with an opening at the distal end of the delivery conduit 12 . Similar to lumen 13 A, lumen 13 B could also be configured only with a side port, only with an opening at the distal end of the delivery conduit, or both. Furthermore, though the illustrated embodiment shows guidewire 90 disposed within lumen 13 B and snare shaft 22 disposed within lumen 13 A, in other embodiments, lumen 13 A may be configured to receive a guidewire and lumen 13 B configured to receive a snare shaft.
FIGS. 8B-8D illustrate cross sectional views of certain embodiments of a two lumen delivery conduit. The delivery conduit may have a substantially circular cross section with semicircular lumens at in FIG. 8B , a “FIG. 8 ” cross section with circular lumens as in FIG. 8C , a circular cross section with one semicircular lumen and one rounded (either circular or elliptical) lumen as in FIG. 8D , or any combination of delivery conduit and lumen cross sectional shapes. For example, a delivery conduit may also have a circular cross section with two circular or elliptical lumens disposed within it. In FIG. 8D a guidewire 90 is disposed within the elliptical lumen 13 B and the snare shaft 22 within the semicircular lumen 13 A. It will be appreciated that in other embodiments the lumen configured to receive the guidewire 90 may be semicircular in shape while the lumen configured to receive the snare shaft 22 may be ellipsoidal.
In certain embodiments the delivery conduit may further include three or more lumens. For example, in one embodiment the snare device may have a first lumen configured to receive a snare shaft, a second lumen configured to receive a guidewire, and a third lumen configured to receive a balloon device.
FIGS. 7A-7D generally may be understood as illustrating potential relative positions of the components of the snare device 10 during therapy. The therapeutic procedure may involve any therapy in which snares or snare devices may be utilized such as removing a fragment (either a foreign object or body matter) from a lumen of the central venous system, for example. To use the device, the physician may first remove the snare device from a sterile package (not shown). A snare shaft 22 may be disposed within the delivery conduit 12 in the packaged configuration. A physician may remove the snare shaft 22 from the delivery conduit 12 by displacing the snare shaft 22 with respect to the delivery conduit 12 in a proximal direction. In embodiments where the snare shaft has a snare loop coupled to each end, the physician will determine which snare loop is desirable to perform the therapy.
Once the snare shaft 22 is removed from the delivery conduit, the physician may deform the snare shaft into a desired configuration. The desired configuration may include multiple bends (including compound bends), a single bend, or no bend at all. The physician may deform the shaft by use of human hands, by placement of the unshaped shaft over a mandrel, or any other means known in the art.
During therapy the delivery conduit 12 may be introduced into a body lumen of a patient. In some embodiments a guidewire 90 may be utilized to position the delivery conduit 12 and navigate the delivery conduit 12 through the body lumen. It will also be appreciated that the snare shaft 22 may be disposed within the delivery conduit 12 when the delivery conduit is initially introduced into the body lumen, or the snare shaft may be inserted into a lumen of the delivery conduit 12 after the delivery conduit is disposed within a body lumen of the patent. Further, the physician may: (A) remove the snare shaft 22 from the delivery conduit before the delivery conduit 12 is introduced into the body, shape the snare shaft 22 , and reinsert the snare shaft 22 into the delivery conduit 12 before the delivery conduit is first introduced into the body; (B) the physician may first introduce the delivery conduit 12 (with the snare shaft 22 disposed inside) into the body, then remove the snare shaft 22 for shaping and reinsertion; (C) the physician may insert the delivery conduit 12 into the body lumen without the snare shaft 22 disposed inside, shape the snare shaft 22 , then insert the snare shaft 22 into the delivery conduit 12 ; (D) or any other combination of these sequences. Furthermore, the physician may remove the snare shaft 22 from the delivery conduit 12 at any point during therapy for shaping or reshaping, regardless of whether the snare shaft 22 has already been shaped.
Once the delivery conduit 12 and snare shaft 22 are positioned and shaped for therapy, the physician may deploy the snare loop 24 by displacing the snare shaft 22 in a distal direction relative to the delivery conduit 12 . As illustrated in FIG. 7A-7D , the snare loop 24 may then be manipulated to surround the fragment F. Once the snare loop 24 is in place, the physician may then displace the snare shaft 22 in a proximal direction with respect to the delivery conduit 12 such that the fragment F is trapped between the snare loop 24 and the delivery conduit 12 , as shown in FIG. 7D . The snare device 10 may then be removed from the body lumen, thus removing the fragment F from the body.
In some embodiments it will be desirable to extend the guidewire 90 beyond the delivery conduit 12 (either through a distal opening or through a side port) prior to deploying the snare loop 24 beyond the delivery conduit 12 . This sequence may reduce the frequency of instances wherein the snare loop 22 inadvertently captures or becomes entangled with the guidewire 90 .
Without further elaboration, it is believed that one skilled in the art can use the preceding description to utilize the present disclosure to its fullest extent. The examples and embodiments disclosed herein are to be construed as merely illustrative and exemplary and not a limitation of the scope of the present disclosure in any way. It will be apparent to those having skill in the art that changes may be made to the details of the above-described embodiments without departing from the underlying principles of the disclosure herein. | A retrieval device with a shapeable snare shaft for use in minimally invasive medical procedures. The retrieval device may further comprise a delivery conduit configured to receive both a snare shaft and a guidewire in one or more lumens. The retrieval device may also include a snare loop at both ends of the snare shaft. | 0 |
FIELD OF THE INVENTION
[0001] This invention relates to gasification equipment of hydrocarbon materials, and, more specifically to a multi-burner gasification reactor fed with slurry or pulverized hydrocarbon materials.
BACKGROUND OF THE INVENTION
[0002] With the development of human society, the bottleneck of energy and environment protection appears gradually, for which people have spent painstaking effort so that energy-related equipment has been increasingly perfected. Gasification reactors have also been developed from original fixed-beds (1920s) and fluidized-beds (1930s) to recent entrained-beds. The typical entrained-bed gasification technologies are GE gasification (former Texaco gasification, U.S. Pat. Nos. 4,637,823, 4,527,997, 5,281,243) and Shell gasification (U.S. Pat. No. 4,799,356). The former is fed with slurry state materials and the latter is fed with pulverized state materials. Some drawbacks of current gasification technologies have appeared in practical applications. For example, GE gasification drawbacks include low carbon conversion (only 94˜95%), low effective gas content (78˜81% of (CO+H 2 ) when fed with coal-water slurry), limited life of refractory bricks near a syngas and slag outlet (only 2000˜3000 hours). The above drawbacks are mainly caused by unreasonable setting of gasification burners. The gasification burner is set at the center line of the top of the gasification reactor vessel, so the residence time distribution of the materials in the reactor is relatively wide, ranging from the shortest 0.01 s to the longest 32 s. The flow field and velocity distribution of GE gasification reactor are shown in FIG. 1 , in which the flow field can be divided into three regions: jet-flow region (I), recirculation-flow region (II) and plug-flow region (III). The materials with short residence time are discharged from the gasification chamber before completion of chemical reactions, which is the ultimate reason for low carbon conversion. Shell gasification drawbacks are: the syngas from the gasification reactor is cooled by recycled clean syngas, and the ratio of the recycled clean syngas to the syngas from the gasification reactor is 0.8; with the same treatment capacity, investment of Shell gasification is more than two times that of the GE gasification; and the gasification reactor is very complex. Shell gasification adopts multiple burners too, but the setting of the burners is not reasonable, which results in large amount of dusts being carried out of the gasification reactor. To increase carbon conversion, Shell gasification adopts return dusts and the setting of burners is also very complex, including startup burner, gasification burner, etc. Even now, different kinds of problems often occur in the Shell gasification plants such as Shuanghuan (Hubei Province) and Anqing (Anhui Province) in China. In view of the above, it is highly desirable in the art that a gasification reactor with better performance be invented.
[0003] The object of this invention is to disclose a multi-burner gasification reactor for gasification of slurry or pulverized hydrocarbon feed materials and industry applications thereof, which can eliminate the above drawbacks.
SUMMARY OF THE INVENTION
[0004] The conception of this invention is as follow:
[0005] On the basis of over 20 years of research in the gasification field, the inventors bring forward the conception of a multi-burner gasification reactor, which has the following main features:
[0006] (1) For the gasification reactions of hydrocarbon materials under high temperature and pressure, the controlled processes are diffusion and mixing which should be reinforced;
[0007] (2) To narrow the distribution of residence time of materials in the gasification reactor (namely, to achieve more reasonable distribution) to increase carbon conversion, appropriate flow field and velocity distribution are necessary, shown in FIG. 2 and FIG. 3 , wherein FIG. 3 is an A-A schematic view of FIG. 2 . The flow field can be divided into six regions: jet-flow region 101 , impinging region 102 , impinging-flow region 103 , recirculation-flow region 104 , reentry-flow region 105 and plug-flow region 106 ;
[0008] (3) To ensure the life of the refractory bricks at the top of the gasification reactor, such as over 8000 hours, impinging flows should have a small downward angle;
[0009] (4) To overcome the effect of thermal expansion of the refractory bricks on burner displacement, brick-supporters should be provided. Simultaneously the brick-supporters can play a role in protection of a thermometric element (namely thermocouples);
[0010] (5) The syngas and slag outlet of the gasification chamber should be enlarged to make sure that the gasification reactor is applicable to the gasification of high ash content hydrocarbon materials, such as sludge.
[0011] Gasification processes take place in the following manner: Slurry or pulverized hydrocarbon materials are injected into the gasification reactor through a special passage, while a gasifying agent (pure oxygen) and steam (only used in pulverized mediums) are injected into the gasification reactor through the special passage too. Oxygen (or together with H 2 O) is injected with a velocity of 30˜200 m/s. Burners are set in pairs and meet at 180 degrees, thus forming an impinging-flow. Since every stream has a slightly downward angle (1˜10 degrees), the upward velocity of the impinging-flow is decreased, which can ensure the life of the refractory bricks at the top of the gasification reactor. In the gasification chamber, main chemical reactions among hydrocarbon material, oxygen and steam are listed as follows:
[0000] C+O 2 ═CO 2 (1)
[0000] C+H 2 O═CO+H 2 (2)
[0000] C+CO 2 ═CO (3)
[0000] CO+H 2 O═CO 2 +H 2 (4)
[0000] C+2H 2 ═CH 4 (5)
[0012] According to the above conception, this invention discloses a multi-burner gasification reactor for gasification of slurry or pulverized hydrocarbon feed materials. Said multi-burner gasification reactor includes:
[0013] an upright cylindrical vessel including a refractory lining layer therein;
[0014] a brick-supporting plate, disposed at the middle of the upright vessel, dividing the upright vessel into two parts: an upper gasification chamber and a lower scrubbing and cooling chamber;
[0015] n pairs (2≦n≦10) of gasification burner chambers disposed on the periphery of said gasification chamber, each pair of which is symmetrically opposed and meets at 180 degrees, the axis of which is at an angle of 1˜10 degrees relative to the horizontal plane, which locate at the horizontal plane where the distance (H) between the gasification burner planes and the top of the reactor vessel is 1˜2 times the inner diameter (D i ) of the gasification reactor, and which can be set as one, two or three layers, and the gasification burner chamber disposed on the top of said gasification chamber being parallel to the axis of the gasification reactor;
[0016] gasification burners disposed in the gasification burner chambers, the gasification burners being coaxial with the gasification burner chambers and being used to introduce the slurry or pulverized hydrocarbon materials into the gasification reactor and to mix them well for gasification reactions;
[0017] the refractory lining can be a cold-wall lining, e.g. the technology disclosed in Chinese Pat. No. ZL 200410067212.8, or a hot-wall lining, e.g. the technology disclosed in Chinese Pat. No. ZL 98110616.1;
[0018] brick-supporters disposed in the refractory brick lining layer;
[0019] a syngas and slag outlet disposed in the center of the supporting-plate, wherein high temperature syngas and melted ash concurrently flow through the syngas and slag outlet, and the high temperature syngas can well carry the flow of the high viscous melted ash;
[0020] a water jacket disposed on the back of the brick-supporting plate, wherein cooling water enters from the bottom of the water jacket and overflows from the top;
[0021] a syngas and slag tube disposed at the lower of the syngas and slag outlet and inserted in the scrubbing and cooling chamber;
[0022] a cooling water ring disposed at the center of the brick-supporting plate and fixed to said brick-supporting plate, wherein water spouting from the cooling water ring chills the high temperature syngas and the melted ash to protect the syngas and slag tube from ablating;
[0023] bubble-breaking plates disposed inside the scrubbing and cooling chamber and out of the syngas and slag tube, wherein the bubble-breaking plates are fixed on the inner side of the gasification reactor vessel by a bubble-breaking plate shelf, and there is some gap between the bubble-breaking plates and the syngas and slag tube, the purpose of the bubble-breaking plates being to break big bubbles and enhance contacting effect of liquid and solid;
[0024] a syngas outlet disposed at the upper portion of the scrubbing and cooling chamber;
[0025] a black water outlet disposed at the lower portion of the scrubbing and cooling chamber;
[0026] a slag water outlet disposed at the bottom of the scrubbing and cooling chamber;
[0027] a high pressure nitrogen blowing pipe disposed at the lower portion of the scrubbing and cooling chamber and inside the syngas and slag tube to blow high pressure nitrogen at regular intervals to remove possible ash accumulated at the syngas and slag outlet in the center of the brick-supporting plate;
[0028] The fire-end profile of the gasification chamber is bell mouth, and the end of the gasification burners is shorter than the refractory lining to prevent the melted ash from blocking the burners after it flows down.
[0029] The gasification burners are multi-channel ones, which can adopt multiple burner styles such as internal mixing or external mixing. For example, for slurry hydrocarbon materials, technology disclosed in Chinese Pat. No. ZL 95111750.5 can be used, and for pulverized hydrocarbon materials, technology disclosed in Chinese Pat. No. ZL 200420114032.6 can be used. The objective of this invention also can be achieved with burners of other kinds, such as the cluster-burner shown in Chinese Pat. Application No. 200610116588.2.
[0030] The multi-burner gasification reactor in this invention can be used to gasify slurry or pulverized hydrocarbon materials, which can be coal, petroleum coke, biomass, waste and other solid hydrocarbon materials.
[0031] The slurry or pulverized hydrocarbon materials (such as coal) with particle diameter smaller than 200 μm are conveyed to the gasification burners, the slurry hydrocarbon materials via a high pressure pump and the pulverized hydrocarbon materials via a carrier gas such as nitrogen or carbon dioxide, respectively. Gasifying agents enter the gasification burner and the mixture of these gasification agents is then injected out of the gasification burner at 30˜200 m/s. An impinging stream is formed by the multiple opposed and slightly downwards-inclined gasification burners, which can intensify mixing and diffusion. Then atomized or dispersed hydrocarbon materials are gasified to produce syngas in the gasification chamber. The high temperature syngas, together with melted ash, enters the scrubbing and cooling chamber to remove ash and then syngas enters the downstream syngas treating units through the syngas outlet. Slag is discharged through the slag water outlet and the black water goes to the downstream water treating units through the black water outlet.
[0032] The gasification temperature is 1350° C. (hot-wall) ˜1700° C. (cold-wall), and the gasification pressure is 0.1˜12 Mpa. Carbon conversion of hydrocarbon materials is 99%, and the effective gas (hydrogen and carbon monoxide) content in the syngas outlet is 80˜94%(depending on the kind and the state of feed);
[0033] For each part of hydrocarbon material by weight, the gasification agent should be 0.4˜1.2 parts, and steam 0˜0.5 parts;
[0034] The gasification agents include oxidant, steam and carbon dioxide;
[0035] The oxidant is selected from the group consisting of oxygen, air and the oxygen-enriched air with 60˜70% oxygen content;
[0036] The weight ratio of the carrier gas (e.g. nitrogen and carbon dioxide) and the hydrocarbon materials is that for each part of the carrier gas, the hydrocarbon materials should be 0.02˜0.8 parts;
[0037] Compared with the current gasification reactors that have been disclosed, this multi-burner gasification reactor shows the significant advantages that the carbon conversion rate is high and can reach 99%, the effective gas content is high; the specific coal consumption and the specific oxygen consumption are low; the distribution of temperature in gasification reactor is homogeneous, so the ablation of the refractory lining caused by local partial high temperature does not happen and the life of the refractory lining is long; this gasification reactor is applicable to a large gasification plant that processes above 3000 tons of coal per day. The syngas produced, which can be used as the raw materials of chemicals, fuel gas, IGCC power generation, hydrogen, synthetic liquid fuel and DRI etc, has wide applications.
BRIEF DESCRIPTION OF THE DRAWINGS
[0038] FIG. 1 is a flow field and velocity distribution diagram of a former Texaco gasification reactor;
[0039] FIG. 2 is a flow field and velocity distribution diagram of the multi-burner gasification reactor of the present invention;
[0040] FIG. 3 is a schematic view of FIG. 2 in the A-A direction;
[0041] FIG. 4 shows a multi-burner gasification reactor for gasification of slurry or pulverized hydrocarbon feed materials;
[0042] FIG. 5 is a top view of FIG. 4 ;
[0043] FIG. 6 is a schematic view showing the structure of a cluster-burner.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0044] Referring to FIG. 4 and FIG. 5 , the multi-burner gasification reactor for gasification of slurry or pulverized hydrocarbon feed materials provided by this invention comprises:
[0045] an upright cylindrical vessel 1 having a refractory lining therein;
[0046] a brick-supporting plate 6 , set in the middle of the vertically cylindrical vessel 1 , dividing said upright cylindrical vessel 1 into an upper gasification chamber 2 and a lower scrubbing and cooling chamber 3 ;
[0047] n pairs (2≦n≦10) of gasification burner chambers 5 set on the side of said gasification chamber 2 , each pair of which is symmetrically opposed and meets at 180 degrees, the axis of which has a 1˜10 degrees downward angle relative to the horizontal plane, which locate at the planes whose distance (H) to the top of the reactor vessel is 1˜2 times the inner diameter (D i ) of the reactor vessel, and which can be set as one, two or three layers. In addition to being set on the periphery of said gasification chamber 2 , the gasification burner chamber 5 also can be set at the top of the gasification reactor vessel 1 , in which the gasification burner chamber 5 is parallel to the axis of the gasification reactor vessel 1 .
[0048] The gasification burner 7 set in the gasification burner chamber 5 is coaxial with the gasification burner chamber 5 . The gasification burners 7 are used to introduce the slurry or pulverized hydrocarbon materials into gasification chamber 2 and to mix them well, for gasification reactions;
[0049] A stoving burner chamber 8 set at the center of the top of the gasification reactor vessel 1 , which serves to install a stoving burner to increase temperature of the gasification reactor. When stopping heating, the stoving burner is pulled out and is replaced by a plug cap 9 . Said plug cap 9 is a truncated cone cylinder made of refractory materials and includes a cooling coil and steel bars inside;
[0050] The refractory lining 4 can be a cold-wall lining or a hot-wall lining;
[0051] Brick-supporters are set in the refractory brick lining 4 , which is composed of a brick-supporter shelf 16 and a ring round plate 22 set on the brick-supporter shelf 16 . The number of the layers of the brick-supporter is 1˜4, and the peripheries of said brick-supporter shelf 16 and said ring round plate 22 are lined with refractory fibers.
[0052] Strip cooling fins 17 are set outside of the gasification reactor vessel 1 where the brick-supporter shelf 16 is set, each brick-supporter shelf 16 corresponding to one strip cooling fin 17 . The strip cooling fin 17 and the brick-supporter shelf 16 are of the same height.
[0053] The syngas and slag outlet 24 is set in the center of the brick-supporting plate 6 , and the flow area of the syngas and slag outlet 24 is designed based on a medium flow rate of 5-10 m/s. The high temperature syngas and melted ash concurrently flow through the syngas and slag outlet. The high temperature syngas can well carry the flow of the high viscous melted ash.
[0054] A water jacket 14 is set on the back of the brick-supporting plate 6 . The cooling water enters from a water inlet 23 at the bottom of the water jacket and overflows from the top.
[0055] A syngas and slag tube 11 is set at the lower portion of said syngas and slag outlet 24 and inserted into the said scrubbing and cooling chamber 3 . The syngas and slag tube 11 is coaxial with the gasification reactor.
[0056] A cooling water ring 10 is set at the center of the brick-supporting plate 6 and fixed to said brick-supporting-plate 6 . The water spouting from the cooling water ring 10 chills the high temperature syngas and the melted ash to protect the syngas and slag tube 11 from ablating;
[0057] Bubble-breaking plates 12 are set in the scrubbing and cooling chamber 3 and at the outer of said syngas and slag tube 11 . Said bubble-breaking plates 12 are fixed at the inner side of the gasification reactor vessel I through a bubble-breaking plate shelf 18 and keeps a gap from the outer side of the syngas and slag tube 11 .
[0058] A syngas outlet 13 is set at the upper portion of said syngas scrubbing and cooling chamber 3 .
[0059] A black water outlet 19 is set at the lower portion of said syngas scrubbing and cooling chamber 3 .
[0060] A slag water outlet 15 is set at the bottom of said syngas scrubbing and cooling chamber 3 .
[0061] A high pressure nitrogen blowing pipe 21 is set at the lower portion of the scrubbing and cooling chamber 3 and inside the syngas and slag tube 11 , at the head of which there is a high pressure nitrogen nozzle 20 to blow high pressure nitrogen at regular intervals, so as to remove possible ash accumulated at the syngas and slag outlet 24 at the center of the supporting-plate 6 .
[0062] Referring to FIGS. 4 and 5 , the fire-end profile of said gasification burner chamber 5 is bell mouth. The included angle of said bell mouth is 20˜60 degrees. The end of the gasification burners 7 is 20˜200 mm shorter than that of the refractory lining to prevent the melted ash from blocking the burners after it flows down.
[0063] The gasification burners are multi-channel ones, which can adopt multiple burner styles such as internal mixing or external mixing. For example, for slurry hydrocarbon materials, technology published by Chinese Pat. No. ZL 95111750.5 can be used, and for pulverized hydrocarbon materials, technology published by Chinese Pat. No. ZL 200420114032.6 can be used. The objective of this invention also can be achieved with burners of other styles. The inventors preferably recommend a type of cluster-burner as disclosed in Chinese Pat. Application No. 200610116588.2, the entirety of which is incorporated herewith by reference. As shown in FIG. 6 , the cluster-burner comprises a housing 25 and N burners 26 (N>1) within the housing 25 , the burners 26 being preferably set vertically in the housing 25 and preferably having their axes parallel with each other.
[0064] The burner 26 comprises an outer sleeve 27 , an inner sleeve 28 set in the outer sleeve 27 , a lower pipe sheet 29 , an upper pipe sheet 30 and a cooling chamber 31 .
[0065] The cooling chamber 31 is set at the outlet 32 of the burner 26 . The cooling chamber 31 comprises a U-type encloser 33 which is fixed to the housing 25 , a cover plate 34 which is set at the upper of the U-type encloser 33 , a cooling water inlet conduit 35 and a water outlet conduit 36 which are both set on the cover plate 34 . It is preferable for the inlet conduit 35 to be inserted into the inner bottom surface of the U-type encloser 33 , and it is preferable for the outlet conduit 36 to be set near the cover plate 34 . The cooing water in the cooling chamber 31 can flow with revolution to improve heat transfer.
[0066] A position-setting plate 37 is set in the intermediate section of the housing 25 in order to restrict the vibration of the burner 26 in working.
[0067] A coal-slurry or other hydrocarbon materials inlet 38 and a gasification agent inlet 39 are both set at the upper portion of the housing 25 . The coal-slurry or other hydrocarbon materials inlet 38 communicates with the inner sleeve 28 , and the gasification agent inlet 39 communicates with the outer sleeve 27 .
[0068] The advantages of the cluster-burner are as follows: Because the flame is relatively short and tends to be rectangular, it is helpful to protect the refractory brick lining at the intermediate or lower portion of the gasification reactor and increase its life. Because the residence time distribution is narrow, it is helpful to increase carbon conversion; Because of the reasonable structure of the cluster-burner, it is helpful to increase the life of the burner.
EXAMPLE 1
[0069] A multi-burner gasification reactor shown in FIG. 1 was used, for which the gasification materials was coal-water slurry, the throughput is 125 t/h coal (3000 t/d coal), the flow rate of coal-water slurry was 210 t/h, the gasification pressure was 6.5 MPa, the hot-wall lining was used, the gasification temperature was 1350° C., the total height of the gasification reactor was 21 m including a gasification chamber with a height of 11 m and a scrubbing and cooling chamber with a height of 10 m, the inner diameter of the gasification chamber vessel was 5.6 m, and 4 layers of bubble-breaking plates were set in the scrubbing and cooling chamber.
[0070] Four opposed gasification burner chambers were set symmetrically at the upper portion of the gasification chamber. The distance between the gasification burner chamber and the top of the gasification reactor was 1.5 times the size of the inner diameter of the gasification chamber vessel; the axis of the gasification burner chambers made an angle of 5 degrees with the horizontal plane; the fire-end of the gasification burner chambers 5 was a bell mouth with an included angle of 30 degrees; the fire-end of the gasification burner was 100 mm shorter than that of the refractory lining.
[0071] The burner was a type of cluster-burner (Chinese Pat. Application No. 200610116588.2). For cluster-burner, the external diameter of the housing 25 was 260 mm and seven burners 26 were set. The diameter of the inner sleeve was 31−3 mm, and the diameter of the outer sleeve was 39.6×3 mm. The tube pitch of the outer sleeves was 80 mm. The total length of the cluster-burner was 2000 mm. The jet velocity of the coal-water slurry in the inner sleeve was about 4 m/s and about 125 m/s in the outer sleeve.
[0072] The coal-water slurry with particle diameter of 30-100 μm at a mass flow rate of 210 t/h and oxygen with 99% oxygen content at a flow rate of 97000 Nm 3 /h were divided evenly into 4 shares, and then were introduced into the gasification chamber by four cluster-burners. After the processes of combustion and gasification reactions in the gasification reactor under the operating pressure of 6.5 MPa and the temperature of 1350° C., the hydrogen and carbon monoxide in syngas with a flow rate of 212500 Nm 3 /h was produced. The high temperature syngas and melted ash were discharged concurrently out of the gasification chamber through the syngas and slag outlet.
[0073] The high temperature syngas, together with melted ash, entered the scrubbing and cooling chamber to remove ash and then syngas entered the downstream syngas treating units through a syngas outlet. Coarse slag was discharged from the gasification reactor to slag discharge equipment, and black water also went to the downstream water treating units through a black water outlet.
[0074] The composition of syngas is as follow: 37% H 2 , 47.5% CO, 14% CO 2 , 0.6% N 2 , and a little H 2 S, Ar, COS, CH 4 , HCN and NH 3 . The syngas can be used to produce fertilizer, methanol, hydrogen, liquid fuel, fuel gas, DRI, to generate electricity, etc., or used in advanced IGCC power generation and poly-generation system.
EXAMPLE 2
[0075] The opposed multi-burner gasification reactor shown in FIG. 1 was used, for which the gasification reactor with pulverized coal had a throughput of 100 t/h (2400 t/d) coal, the gasification pressure was 4.0 MPa, the refractory lining of the gasification reactor was water screen, the gasification temperature was 1600° C., the total height of the gasification reactor was 22 meters including a gasification chamber with a height of 12 m and a scrubbing and cooling chamber with a height of 10 m, the inner diameter of the gasification chamber was 2.5 meters, and 4 layers of bubble-breaking plates were set in the scrubbing and cooling chamber.
[0076] Four opposed gasification burner chambers were set symmetrically at the upper portion of the gasification chamber. The distance between the gasification burner chamber and the top of the gasification reactor was 1.5 times the size of the inner diameter of the gasification chamber vessel; the axis of the gasification burner chambers made an angle of 4 degrees with the horizontal plane; the fire-end of the gasification burner chambers 5 was a bell mouth with an included angle of 30 degrees; the fire-end of the gasification burner was 100 mm shorter than that of the refractory lining.
[0077] The burner described by Chinese Pat. No. 200420114032.6 was chosen as the gasification burner.
[0078] The pulverized coal with particle diameter of 30-100 μm at a mass flow rate of 100 t/h coal, pure oxygen with 99% oxygen content at a flow rate of 60000 Nm 3 /h and superheated steam with a flow rate of 72 t/h and a temperature of 430° C., were divided evenly into four shares, and introduced into the gasification chamber by four burners. Then combustion reaction and gasification reaction occurred under the operating pressure of 4.0 MPa and the operating temperature of 1600° C. in the gasification chamber. Finally the hydrogen and carbon monoxide in syngas with a flow rate of 190000 Nm 3 /h was produced. The high temperature syngas and melted ash were concurrently discharged out of the gasification chamber through the syngas and slag outlet.
[0079] The high temperature syngas, together with melted ash, entered the scrubbing and cooling chamber to remove ash and then syngas entered the downstream syngas treating units through a syngas outlet. Coarse slag was discharged from the gasification reactor to slag discharge equipment, and black water also went to the downstream water treating units through a black water outlet.
[0080] The composition of syngas is as follow: 31% H 2 , 59% CO, 4% CO 2 , 5% N 2 , and a little H 2 S, Ar, COS, CH 4 , HCN and NH 3 . The syngas was used to produce fertilizer, methanol, hydrogen, liquid fuel, fuel gas, DRI, electricity generation, or advanced IGCC power generation and poly-generation system.
[0081] The preferred embodiments of the invention have been described in detail as above. However, it shall be appreciated that, without departing the spirit of the invention, numerous amendments, changes and modifications are possible to a skilled person in the art. Therefore, the scope of the invention is solely intended to be set out in the claims. | Disclosed is a multi-burner gasification reactor for gasification of slurry or pulverized hydrocarbon feed materials and industry applications thereof. Burners are disposed on the periphery or top of a gasification reactor vessel, wherein the side burners are at a small downward angle relative to the horizontal plane, which can prolong the life of refractory bricks. The operating pressure of the gasification reactor is 0.1˜12 MPa, and the operating temperature thereof is 1350° C.˜1700° C. The gasification reactor is applicable to a hot-wall lining as well as a cold-wall lining. The notable advantages of the gasification reactor are carbon conversion is high and can reach 99%, and the effective gas content is high; specific coal consumption and specific oxygen consumption are low; and it is applicable to a large coal gasification plant that processes above 3000 tons of coal per day. | 2 |
This is a continuation of application Ser. No. 895,507, filed on Aug. 11, 1986, now U.S. Pat. No. 4,705,170.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is broadly concerned with synthetic resin dunnage supports designed for cushioning and protecting elongated fluorescent tubes during packing and shipping thereof. More particularly, it is concerned with such supports which are especially configured to permit automated dispensing of individual supports during the packaging process, while giving essentially equivalent or superior protection to the tubes, as compared with conventional dunnage formed of molded pump material.
2. Description of the Prior Art
Generally speaking, elongated fluorescent tubes are packaged in long corrugated paper cartons. In order to protect the tubes during packaging and in transit, the respective ends of the tubes are normally supported by inserts or dunnage elements. Typically, such dunnage elements include elongated tube-receiving sockets, together with design configurations (e.g., hollow triangular marginal wall portions) which serve to absorb potentially destructive impact forces.
Heretofore, most commercially used tube supports have been formed from molded pulp or paperboard. This material can be readiy fabricated in desired shapes, is low in cost, and provides the requisite degree of protection against tube breakage. However, molded pulp dunnage elements suffer from a significant problem relating to the handling and packaging thereof. That is to say, many manufacturers would prefer to package their fluorescent tubes on a completely automated basis. This in turn necessitates that the dunnage elements employed be machine dispensable. Experience has proved though that pump supports have a tendency to stick together when nested in a stack, to the point that automated dispensing machines simply cannot be used on an efficient basis. In fact, it has been the practice to position a worker at the dispensing station in order to clear the constant hang-ups of paperboard supports and to assure relatively smooth operation of the automated dispensing equipment. As can be appreciated, use of a worker in this context largely negates the cost advantage of automated dispensing.
The problems of dispensing paperboard dunnage elements are believed to stem from the fact that these elements are of varying thicknesses and quality. Moreover, during high humidity conditions these elements tend to adhere to one another, which further compounds the separation and dispensing problem.
In short, the molded pulp dunnage of the prior art is seriously deficient from the standpoint of easy, cost effective handling and dispensing thereof, and therefore fluorescent tube manufacturers have been searching for an acceptable substitute which meets the dictates of automated handling.
SUMMARY OF THE INVENTION
The present invention overcomes the problems noted above, and provides synthetic resin dunnage supports which are particularly designed for fast, sure, individual automated dispensing while at the same time giving tube protection essentially equivalent or superior to conventional molded pulp dunnage.
In preferred forms, the tube support of the invention is in the form of an integral body fabricated from thin synthetic resin sheet material (e.g. polyvinyl chloride having a thickness of from about 0.13 to 0.018 inches). The integral body has concavo-convex walls presenting a number of elongated, open top, parallel, juxtaposed concave tube-receiving regions or sockets, and corresponding convex underside wall surfaces. Moreover, the integral tube support is provided with spacer means which prevents complete nesting of plural supports and serves to define substantially uniform, elongated, laterally-extending spaces between adjacent interfitted supports. In this fashion, automatic dispensing equipment can be used for dispensing of the supports on an individual basis from a stack thereof.
Preferably, the dunnage support is provided with an elongated, rearward extending, thin rear side lip having an underside presenting an abutment surface. Each lip in turn carries spacer means for preventing complete nesting of plural supports in a stack, to define the aforementioned substantially uniform, elongated, laterally extending spaces between adjacent interfitted supports in order to allow insertion of automatic dispensing equipment therebetween. The lip spacer means is advantageously in the form of a plurality of upstanding, laterally spaced apart nibs carried by the lip. Such nibs should have a vertical height of at least about 1/8 inch and preferably from about 1/8 to 3/8 inches in height. Furthermore, the front edge of each support is advantageously formed to provide ledge structure serving to maintain the desirable spacing between individual interfitted tube supports.
The nibs carried by respective element lips are also preferably laterally offset from one another, so that in a stack of interfitted supports positive spacing between the supports is assured. In like manner, the front side ledges are alternately arranged in respective interfitted supports so as to provide the needed spacing function. Accordingly, at least two separate molds are employed in the fabrication of the dunnage supports in order to provide the alternating nib and ledge arrangement in accordance with the invention. In actual practice, many (e.g., five) separate molds are used, each with a correspondingly different nib and alternate ledge placement, so that in an upright, interfitted stack of the supports, a particular style of support occurs only every sixth support.
The dunnage support of the invention also includes a number of unique features serving to provide adequate breakage protection for the fluorescent tubes. In particular, the concavo-convex socket-defining walls of the supports preferably include a first plurality of axially spaced apart, upwardly opening and diverging tube-engaging arcuate first sections each having a radius conforming with the circular sidewall of a fluorescent tube. Moreover, a second plurality of axially spaced apart, downwardly opening and diverging tube-engaging arcuate second sections are also provided, and here again these second sections have a radius conforming with the circular sidewall of a fluorescent tube. The upwardly opening first sections, and the downwardly opening second sections, are alternated along the length of each of the tube-receiving sockets, with the downwardly opening sections being located vertically below the upwardly opening sections. In this fashion, a single dunnage support can engage and protect two layers of fluorescent tubes, while the spaced apart tube-engaging sections give cushioned protection to the tubes. Such protection is enhanced by provision of striations or small cushioning ribs in the faces of each of the tube-engaging sections. Such ribs have been found to further absorb destructive impact in order to fully protect the fluorescent tubes.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a dunnage support in accordance with the invention;
FIG. 2 is a plan view of the support depicted in FIG. 1;
FIG. 3 is a side elevational view of the support illustrated in FIGS. 1 and 2, viewing the front side thereof;
FIG. 4 is a side elevational view of the dunnage support of FIGS. 1-3, depicting the rear side thereof;
FIGS. 5 and 6 and respective end elevational views of the dunnage support;
FIG. 7 is a sectional view taken along line 7--7 of FIG. 4;
FIG. 8 is a fragmentary vertical sectional view illustrating a pair of dunnage supports in use, with the supports in operative, supporting engagement with fluorescent tubes; and
FIG. 9 is a front side elevational view of an interfitted stack of dunnage supports in accordance with the invention, illustrating the provision of substantially uniform, laterally extending spaces between individual supports permitting ready machine dispensing of the supports.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Turning now to the drawings, a dunnage support 10 is illustrated in FIGS. 1-6. The support 10 is in the form of an integral, thermo-formed body of synthetic resin material. Most preferably, the material is polyvinyl chloride sheeting having an initial thickness before forming of 0.014 inches.
The support 10 includes an upstanding rear sidewall 12, an opposed, upstanding hollow front sidewall 14, opposed end walls 16, 18, and a rearwardly extending rear side lip 20.
The overall support 10 is further provided with a total of six concavo-convex wall sections 22 which cooperatively present a plurality of individual, elongated, open-top, parallel, juxtaposed concave tube-receiving sockets or regions 24. It will be noted in this respect that the regions 24 terminate at rear wall 12, and accordingly, the wall 12 presents in overall configuration a scalloped appearance. The wall sections 22 are joined at their respective apices by means of elongated, rectangular, fore and aft extending connector walls 26, the latter being notched as at 28 adjacent front wall 14. The endmost wall sections 22 are joined to the adjacent end walls 16, 18, by means of a similar connector wall 30, each of the latter being provided with three spaced apart upstanding spacers 32.
In more detail, it will be seen that rear sidewall 12 is integrally joined with each of the sidewalls 16, 18, at smooth, rounded rear corners 34. Moreover, the wall 12 is provided with a total of five formed recessed 36 therein, respectively located directly beneath an associated connector wall 26 in the region between the tube-receiving regions 24.
Attention is next directed to FIGS. 1 and 3 which depict the particular construction of front wall 14. In this regard, it will be seen that the front wall 14 is integrally connected with the sidewalls 16, 18 at smooth, rounded corners 38. Moreover, the front wall 14 includes a series of openings 40 therein respectively in communication and alignment with the corresponding tube-receiving regions 24. It will be noted that four openings 40 of relatively deep configuration are provided, along with two openings 40a of somewhat shallower configuration. The openings 40, 40a are designed to receive and accommodate the connector prongs of fluorescent tubes received within the supports, as those skilled in the art will readily appreciate. However, it will be observed that each of the recesses 40, 40a, at the left hand margin thereof as viewed in FIGS. 1 and 2, includes a somewhat triangularly-shaped ledge or platform 42 and a correspondingly shaped relieved zone. As explained previously, other embodiments of the support provide a different placement for the platforms 42 and relieved zones. In particular, in another embodiment of the invention, the platforms 42 and relieved zones are provided at the righthand margin of each recess 40, 40a, as opposed to the configuration specifically depicted in FIG. 1. Thus, and considering an interfitted stack of the tube supports, the left and righthand placement of platforms 42 would alternate in the stack so as to establish and maintain a proper spacing between individual interfitted supports.
Referring particularly to FIGS. 2 and 3, it will further be seen that front wall 14 is provided with a total of five somewhat triangularly shaped, arcuate in cross section, open top, upwardly diverging recessed zones 44. These zones are defined by correspondingly shaped indentations in wall 14 as will be readily seen, with such indentations being in opposed relationship to each of the five connector walls 26 (see FIG. 2). As a result of this configuration, it will be perceived that each of the connector walls 26, at the region of front wall 14, is somewhat Y-shaped in configuration, with the base of the Y extending from the corresponding notch 28, and with the bifurcated portion thereof surrounding and defining the upper end of each zone 44. As readily observable from FIGS. 1 and 2, front wall 14 presents an effective thickness attributable to the noted Y-shaped sections together with the bottom walls 46 and 46a of the respective openings 40 and 40a. In addition, the overall front wall 14 presents an upright inner surface in the form of respective arcuate walls 48 joined to the Y-shaped sections and opening-defining walls and extending downwardly therefrom for joinder with the concavo-convex walls 22. The arcuate walls 48 in turn define an upright abutment surface for the end of a fluorescent tube situated within each corresponding region 24.
Rear side lip 20 is provided with a plurality, here seven, of upstanding spacer nibs 50. As illustrated, the nibs 50, in the depicted embodiment, are located at the ends of the lip 20, and just to the left of each recess 36. The purpose of these nibs 50 will be made clear hereinafter.
Each of the concavo-convex wall sections 22 include a stepped, arcuate, end cap-receiving wall portion 52 which extends rearwardly from each associated wall 48 and terminates at the frontmost end of the associated notches 28 as shown. The wall portions 52 as indicated receive the metallic end caps provided on the fluorescent tubes.
The remainder of the concavo-convex wall sections extending rearwardly from the portions 52 to rear wall 12 are in the form of alternating downwardly and upwardly opening, vertically spaced apart arcuate tube-engaging wall sections 54, 56. This is to say, the majority of the length of each concavo-convex wall section 22 includes a plurality of axially spaced apart, arcuate, upwardly opening and diverging wall sections 56 presenting a radius of curvature conforming to that of the sidewall of a fluorescent tube. These spaced apart wall sections 56, at their respective side margins, merge into and form a part of similarly curved main sidewall portions 58 which extend upwardly and are integral with the upper connector walls 26.
The concavo-convex walls 22 further include a second plurality of downwardly opening and diverging wall portions 54 which similarly have a radius of curvature conforming to the sidewall of a fluorescent tube. The respective marginal ends of each wall section 54 are joined with upwardly extending walls 60 (see FIG. 8) which extend upwardly to merge into main wall portion 58. The alternating walls sections 54, 56 are joined together by means of vertical walls 62 in order to maintain the wall sections in vertically spaced relationship to one another. As best seen in FIG. 8, each upwardly opening wall section 56 is spaced above the adjacent wall section 54. Indeed, the lateral side margins of the wall sections 54 extend slightly below the bottom edge of the sidewalls 16, 18, and rear wall 14.
Each of the wall sections 54, 56 is provided with a plurality of relatively small cushioning striations or ribs 64 formed therein during the vacuum forming process of the dunnage support 10. In like manner, each end cap-receiving wall portion 52 is similarly striated.
The element 10 is formed in a female mold so that the thickness of each of the upper connector walls 26, 30 is greater than that of the lower downwardly opening wall sections 54. Indeed, the thickness of the endmost portions of the wall sections 54 are on the order of 0.004 inch, and are effectively transluscent. On the other hand, the connector walls 26, 30 are virtually the same thickness as the starting sheet material, or preferably about 0.014 inch.
Attention is next directed to FIG. 9 which depicts a vertical stack 66 of interfitted dunnage supports in accordance with the invention. This stack is made up of two particular embodiments of the dunnage supports, namely the supports 10 fully described above, together with alternating supports 10a. The supports 10a are in all respects identical with the supports 10, save for the fact that in the supports 10a, the nibs 50a thereof are laterally offset from the nibs 50 of the supports 10, and the ledges or platforms thereof (not shown) are laterally offset from the platforms 42. As a consequence of this construction, it will be seen that the nibs 50, 50a alternate in a stairstep fashion throughout the stack 66; furthermore, the spacing platforms of the supports 10, 10a similarly alterante in a stairstep fashion. By virtue of this configuration, each of the nibs 50, 50a contacts the planar underside of the lip of the support next above in the stack; likewise, each individual set of ledges or platforms engages the full heighth wall of the Y-shaped section of the next adjacent support. The heighth of the nibs and the vertical recess of the platforms are correlated so as to maintain an even spacing between individual supports about the entire periphery thereof. This prevents full nesting of the respective supports 10, 10a and effectively presents a series of substantially even, elongated spaces 68 between individual dunnage supports in the stack 66. As a consequence, the stack 66 can be placed in automatic dispensing equipment, and the spaces 68 afford adequate clearance for the insertion of dispensing equipment between individual supports in the stack. Thus, such dispensing equipment can be used to good effect to achieve easy, high speed automated dispensing of the individual supports.
Although PVC having a thickness of 0.014 inch is the preferred sheet material for use in forming the supports of the invention, other current of future equivalent materials may also be used. For example, it is believed tha thermoplastic polyester or polyethylene terephthalate synthetic resins can also be used to good effect in the invention, with the thicknesses of these materials being substantially the same as outlined above. In order to provide the most advantageous protection for the fluorescent tubes, it is preferred to employ synthetic resin materials having a durometer value (Shore D per ASTM D-2240) of from about 80 to 90 (most preferably 84), and a modulus of elasticity of from about 400,000 to 440,000, ASTM D-790 (most preferably 420,000). The most preferred PVC material further has a specific gravity 1.35, ASTM D-792; a tensile strength of 6750 psi, ASTM D-638; a tensile modulus of 315,000 psi, ASTM D-638; a flexural modulus of 420,000 psi, ASTM D-790; and a deflection temperature at 264 psi of 58° C., ASTM D-648.
In addition, the various structural features of the dunnage supports assures that a package of fluorescent tubes with individual supports between respective layers thereof can withstand potentially destructive impact forces. That is to say, a given package containing four layers of tubes would make use of five dunnage supports at each end of the tubes, with four of the supports receiving the tubes as illustrated in FIG. 8, and with one support being inverted. In any event, actual testing with the dunnage elements hereof has proved that they are fully capable of supporting and protecting fluorescent tubes in a manner at least equivalent to conventional pulp dunnage supports. Such protection is believed to stem from the inherent flexibility of the synthetic resin material, and also by virtue of the striations 64 provided on the tube-engaging surfaces. Furthermore, the various recesses such as the notches 28 and zones 44, afford a controlled collapse to the dunnage elements which has been found to safely absorb potentially destructive forces.
In addition to the foregoing, it has been found that it is advantageous to provide a spacing between the longitudinal axes of adjacent pairs of tube-receiving regions 24 slightly differently than the spacing between other parts of axes. This slight differential is in itself believed to enhance the protective function during an impact situation. To further enhance the protective function, the shape, spacing, contours, dimensions and ribbed texture of the areas 54, 56, 58, 60 and 62 are individually spaced to be slightly different from one anther.
Finally, it will also be noted that the central connector wall 26 is slightly wider than the remaining connector walls on either side thereof. This not only enhances the strength of the central section of the support, but also facilitates automated insertion of thin vertical corrugated material between the central tubes during the packing process.
As indicated above, a prime feature of the present invention resides in the provision of dunnage supports designed to only incompletely nest in a stack thereof so as to present uniform spacings between pairs of elements and thus facilitate machine dispensing thereof. While in the preferred form of the invention use is made of an alternating nib and ledge arrangement respectively located along the rear and front side edges of the supports, the invention is not so limited. Thus, it will be appreciated that there are a multitude of ways to form spacing elements in the supports themselves in such a manner as to insure the partial nesting feature described above. All such equivalents are therefore deemed to be within the spirit and scope of the present invention. | Molded synthetic resin dunnage supports for packing of elongated fragile fluorescent tubes are provided which are designed for automated dispensing during packaging and give protection against tube breakage at least equivalent to that of conventional molded pulp supports. In preferred forms, the dunnage support is formed from polyvinyl chloride sheet material (0.014 inch thickness) and includes plural juxtaposed tube-receiving sockets together with a rear side lip and front side ledge platforms; the lip carries laterally spaced upright nibs which, in conjunction with the ledge platforms, prevent complete nesting of the supports, so that an interfitted support stack presents substantially even access spaces between individual supports for easy machine dispensing. The tube-receiving sockets are provided with alternating, vertically spaced, upwardly and downwardly opening arcuate, striated tube-engaging sections so that a single support can simultaneously engage and cushion a pair of tube layers in a shipping carton. The dunnage design affords a high degree of protection for the packaged tubes and can safely absorb potentially destructive impacts without tube breakage. | 1 |
[0001] The present invention relates to a novel gene 763 which is essential to fungal pathogenesis. The invention relates to polynucleotides 763, to polypeptides 763, to host organisms expressing a polypeptide 763 and to uses thereof for identifying novel antifungal molecules.
[0002] The principle of using genes of pathogenic fungi, entirely or in part, in tests for identifying novel molecules active against these fungi is in itself known (in Antifungal Agents: Discovery and Mode of Action, G. K. Dixon, L. G. Coppong and D. W. Hollomon eds, BIOS Scientific Publisher Ltd, Oxford UK). With this aim, knowledge of the genome of a given pathogenic fungus constitutes an important step for the implementation of such tests. However, the simple knowledge of a given gene is not sufficient to attain this objective, it also being necessary for the gene chosen as a target for potential fungicidal molecules to be essential to the life of the fungus, inhibition thereof by the fungicidal molecule leading to death of the fungus, or essential to the pathogenesis of the fungus, inhibition thereof not being lethal for the fungus but simply inhibiting its pathogenic capacity. This second category of potential target genes for fungicidal molecules is particularly important for the development of a new generation of fungicidal products more favorable to the environment, which specifically attack only the pathogenic capacity of pathogenic fungi.
[0003] The present invention relates to the identification and cloning of a novel gene 763 which is essential for fungal pathogenesis. A mutant 763 of Magnaporthe grisea , in which the gene is inactivated, exhibits a pathogenesis reduced by 95%. Gene 763 encodes a transcription factor comprising a motif of the bZIP type, composed of a dominant basic sequence-specific DNA binding motif followed by another termed “leucine zipper motif”, required for dimerization of the protein. This motif is characteristic of a vast family of proteins which regulate gene expression. The expression of gene 763 is detected during the early stages of plant infection. The invention also relates to the use of gene 763 for identifying novel antifungal molecules and the use of gene 763 for identifying other genes involved in fungal pathogenesis, the expression of which is regulated by 763.
DESCRIPTION OF THE SEQUENCE LISTING
[0004] SEQ ID No. 1: Gene 763 of Magnaporthe grisea
[0005] SEQ ID No. 2: cDNA of gene 763 of Magnaporthe grisea
[0006] SEQ ID No. 3: Polypeptide 763 of Magnaporthe grisea
[0007] SEQ ID No. 4: cDNA of gene 763 of Neurospora crassa
[0008] SEQ ID No. 5: Polypeptide 763 of Neurospora crassa
DESCRIPTION OF THE INVENTION
Polynucleotides
[0009] The present invention relates to the polynucleotides comprising a fungal gene 763. Gene 763 can be isolated from phytopathogenic fungi such as, for example, Botrytis cinerea, Mycosphaerella graminicola, Stagnospora nodorum, Blumeria graminis, Colleotrichum lindemuthianum, Puccinia graminis, Leptosphaeria maculans, Fusarium oxysporum, Fusarium graminearum and Venturia inaequalis . Advantageously, gene 763 is isolated from phytopathogenic fungi of the genus Magnaporthe . Preferably, the polynucleotides of the invention comprise a gene 763 of Magnaporthe grisea . Preferentially, the polynucleotides of the present invention comprise the coding sequence of a gene 763 of Magnaporthe grisea.
[0010] The term “polynucleotides 763” denotes all of the polynucleotides of the present invention, preferably the polynucleotides of the genomic sequence of 763, the polynucleotides of the cDNA sequence of 763, and also the polynucleotides encoding the polypeptides 763 of the present invention. The term “polynucleotides 763” also denotes recombinant polynucleotides comprising said polynucleotides.
[0011] According to the present invention, the term “polynucleotide” is intended to mean a single-stranded nucleotide chain, or the chain complementary thereto, or a double-stranded nucleotide chain, which may be of the DNA or RNA type. Preferably, the polynucleotides of the invention are of the DNA type, in particular double-stranded DNA. The term “polynucleotide” also denotes modified polynucleotides and oligonucleotides.
[0012] The polynucleotides of the present invention are isolated or purified from their natural environment. Preferably, the polynucleotides of the present invention can be prepared using the conventional molecular biology techniques as described by Sambrook et al. (Molecular Cloning: A Laboratory Manual, 1989) or by chemical synthesis.
[0013] The invention relates to polynucleotides comprising the genomic sequence of gene 763 of Magnaporthe grisea SEQ ID No. 1. This genomic sequence comprises 4 exons (positions 723-770, 925-1194, 1273-1554 and 1663-1778 of SEQ ID No. 1), 3 introns (positions 771-924, 1195-1272 and 1555-1662 of SEQ ID No. 1), and 5′ and 3′ regulatory sequences.
[0014] In a preferred embodiment of the invention, the polynucleotides of the genomic sequence of 763 comprise a polynucleotide chosen from the following polynucleotides:
a) the polynucleotide of SEQ ID No. 1, b) a polynucleotide comprising at least one exon of SEQ ID No. 1; c) a polynucleotide comprising a combination of exons of SEQ ID No. 1.
[0018] The present invention also relates to a polynucleotide comprising a 5′ or 3′ regulatory sequence of gene 763 of Magnaporthe grisea . In a first embodiment, the invention relates to a polynucleotide comprising the promoter of gene 763 of Magnaporthe grisea , the sequence of which is included between position 1 and position 705 of SEQ ID No. 1. In another embodiment, the invention relates to a polynucleotide comprising a biologically active fragment of the promoter gene 763 of Magnaporthe grisea , the sequence of which is included between position 1 and position 705 of SEQ ID No. 1.
[0019] The expression “biologically active fragment” is above intended to mean a polynucleotide having promoter activity, and more particularly promoter activity in fungi. The techniques which make it possible to evaluate the promoter activity of a polynucleotide are well known to those skilled in the art. These techniques conventionally involve the use of an expression vector comprising, in the direction of transcription, the polynucleotide to be tested and a reporter gene (see Sambrook et al., Molecular Cloning: A Laboratory Manual, 1989).
[0020] The invention also relates to polynucleotides comprising the cDNA of 763 of Magnaporthe grisea of SEQ ID No. 2. The cDNA gene 763 of Magnaporthe grisea comprises the coding sequence of gene 763 and also a 5′ UTR regulatory sequence and a 3′ UTR regulatory sequence. The invention more particularly relates to polynucleotides comprising the coding sequence of gene 763 of Magnaporthe grisea , the sequence of which is included between position 17 and position 733 of SEQ ID No. 2.
[0021] The invention also extends to the polynucleotides comprising a polynucleotide chosen from the following polynucleotides:
a) the polynucleotide of SEQ ID No. 1; b) the polynucleotide of SEQ ID No. 2; c) the polynucleotide of SEQ ID No. 4; d) a polynucleotide homologous to a polynucleotide as defined in a) or b) or c); e) a polynucleotide capable of selectively hybridizing to a polynucleotide as defined in a) or b) or c).
[0027] According to the invention, the term “homologous” is intended to mean a polynucleotide having one or more sequence modifications compared to the reference sequence. These modifications may be deletions, additions or substitutions of one or more nucleotides of the reference sequence. Advantageously, the percentage homology will be at least 70%, 75%, 80%, 85%, 90%, 95% and preferably at least 98%, and more preferentially at least 99%, relative to the reference sequence. The methods for measuring and identifying homologies between nucleic acid sequences are well known to those skilled in the art. The PILEUP or BLAST programs (in particular Altschul et al., J. Mol. Evol. 36:290-300, 1993; Altschul et al., J. Mol. Biol. 215:403-10, 1990; Altshul et al., NAR 25:3389-3402, 1997) may, for example, be used. Preferably, the default parameters will be used. The invention therefore relates to polynucleotides comprising polynucleotides exhibiting at least 70%, 75%, 80%, 85%, 90%, 95%, 98% and preferably at least 98%, and more preferentially at least 99%, homology with the polynucleotides 763, the polynucleotides of SEQ ID Nos. 1-2 or the polynucleotides of SEQ ID No. 4. Preferably, the invention relates to a polynucleotide comprising a polynucleotide of at least 50, 100, 200, 300, 400, 500, 1 000 nucleotides exhibiting at least 70%, 75%, 80%, 85%, 90%, 95%, 98% and preferably at least 98%, and more preferentially at least 99%, homology with the polynucleotides 763, the poly-nucleotides of SEQ ID Nos. 1-2 or the polynucleotides of SEQ ID No. 4. Preferably, the polynucleotides homologous to a reference polynucleotide conserve the function of the reference sequence.
[0028] According to the invention, the expression “sequence capable of selectively hybridizing” is intended to mean the sequences which hybridize with the reference sequence at a level significantly greater than the background noise. The level of the signal generated by the interaction between the sequence capable of selectively hybridizing and the reference sequences is generally 10 times, preferably 100 times more intense than that of the interaction of the other DNA sequences generating the background noise. Stringent hybridization conditions which allow selective hybridization are well known to those skilled in the art. In general, the hybridization and washing temperature is at least 5° C. below the Tm of the reference sequence at a given pH and for a given ionic strength. Typically, the hybridization temperature is at least 30% for a polynucleotide of 15 to 50 nucleotides and at least 60° C. for a polynucleotide of more than 50 nucleotides. By way of example, the hybridization is carried out in the following buffer: 6×SSC, 50 mM Tris-HCl (pH 7.5), 1 mM EDTA, 0.02% PVP, 0.02% ficoll, 0.02% BSA, and 500 μg/ml denatured salmon sperm DNA. The washes are, for example, performed successively at low stringency in a 2×SSC, 0.1% SDS buffer, at medium stringency in a 0.5×SSC, 01% SDS buffer and at high stringency in a 0.1×SSC, 0.1% SDS buffer. The hybridization may, of course, be carried out according to other usual methods well known to those skilled in the art (see in particular Sambrook et al., Molecular Cloning: A Laboratory Manual, 1989). The invention therefore relates to polynucleotides comprising a polynucleotide capable of selectively hybridizing with the polynucleotide of SEQ ID Nos. 1-2 or the polynucleotide of SEQ ID No. 4. Preferably, the invention relates to a polynucleotide comprising a polynucleotide of at least 50, 100, 200, 300, 400, 500, 1 000 nucleotides, capable of selectively hybridizing with the polynucleotide of SEQ ID Nos. 1-2 or the polynucleotide of SEQ ID No. 4. Preferably, the polynucleotides which selectively hybridize to a reference polynucleotide conserve the function of the reference sequence.
[0029] Preferably, the polynucleotides of the present invention conserve the function of gene 763 of Magnaporthe grisea and encode a transcription factor which is essential to the pathogenesis of the fungus, and which is expressed at the beginning of the infectious state.
[0030] Preferentially, the polynucleotides of the present invention complement a mutant 763 of Magnaporthe grisea and restore its pathogenicity for rice and barley. A mutant 763 according to the invention is a mutant of Magnaporthe grisea in which the gene 763 of SEQ ID No. 1 is inactivated using techniques well known to those skilled in the art.
[0031] The present invention also relates to allelic variants or homologues of gene 763 of Magnaporthe grisea.
[0032] The present invention also relates to the identification and cloning of genes homologous to gene 763 of Magnaporthe grisea in other phytopathogenic fungi. Preferably, these homologous genes can be isolated or cloned from a phytopathogenic fungus chosen from Botrytis cinerea, Mycosphaerella graminicola, Stagnospora nodorum, Blumeria graminis, Colleotrichum lindemuthianum, Puccinia graminis, Leptosphaeria maculans, Fusarium oxysporum, Fusarium graminearum and Venturia inaequalis . A subject of the invention is thus the use of a polynucleotide or of a fragment of a polynucleotide of SEQ ID No. 1 and of SEQ ID No. 2 according to the invention, for identifying homologous genes in other phytopathogenic fungi. The techniques for cloning homologous genes 763 in other phyto-pathogenic fungi are well known to those skilled in the art. The cloning is carried out, for example, by screening cDNA libraries or genomic DNA libraries with a polynucleotide or a fragment of a polynucleotide of SEQ ID No. 1 and of SEQ ID No. 2. These libraries can also be screened by PCR using specific or degenerate oligonucleotides derived from SEQ ID No. 1 or from SEQ ID No. 2. The techniques for constructing and screening these libraries are well known to those skilled in the art (see in particular Sambrook et al., Molecular Cloning: A Laboratory Manual, 1989). Phytopathogenic fungus genes 763 may also be identified in the databases by nucleotide or protein BLAST using SEQ ID Nos. 1-3.
[0033] Preferably, the cloned genes conserve the function of gene 763 of Magnaporthe grisea and encode a transcription factor which is essential to the pathogenesis of the fungus, and which is expressed at the beginning of the infectious stage. The sequences of the cloned genes can be analyzed according to known methods in order to establish that they encode a fungal transcription factor and in particular in order to establish that they encode a polypeptide comprising a motif of the bZIP type, composed of a dominant basic sequence-specific DNA binding motif followed by another termed “leucine zipper motif”, required for dimerization of the protein. Moreover, the techniques for establishing that a known gene is essential to the pathogenesis of a fungus are known to those skilled in the art. For example, the gene studied is inactivated in the fungus using conventional molecular biology techniques; mention will in particular be made of replacement of the gene with a marker gene by homologous recombination. The decrease in pathogenesis of the fungus comprising the inactivated gene is analyzed using phenotypic tests. Preferably, the inactivation of the homologous gene causes a decrease in pathogenesis of at least 95%. The techniques for analyzing the expression of a gene in the various developmental stages of the fungus, and more particularly at the beginning of an infection, are also well known to those skilled in the art. Typically, total RNAs or mRNAs (poly A+) are prepared from the various developmental stages of the fungus. These RNAs are then analyzed by RT-PCR or by Northern Blotting in order to determine the level of expression of the gene. Other techniques well known to those skilled in the art may be used in order to establish that the polynucleotides of the invention conserve the function of gene 763 of Magnaporthe grisea . Mention will be made in particular of complementation of mutants 763 followed by tests for restoration of the pathogenesis of the fungus.
[0034] A blast search in databases made it possible to identify a homologue of gene 763 of Magnaporthe grisea in Neurospora crassa . This novel gene was identified by blasting non-annotated genomic sequences. The cDNA of this Neurospora gene 763 corresponds to SEQ ID No. 4 and the Neurospora polypeptide 763 corresponds to SEQ ID No. 5.
[0035] A subject of the invention is also polynucleotides comprising a polynucleotide encoding a polypeptide chosen from the following polypeptides:
a) the polypeptide of SEQ ID No. 3; b) the polypeptide of SEQ ID No. 5; c) a polypeptide homologous to a polypeptide as defined in a) or b); d) a biologically active fragment of a polypeptide as defined in a) or b).
Polypeptides
[0040] The present invention also relates to polypeptides 763 of a phytopathogenic fungus, and more particularly of Magnaporthe grisea . The term “polypeptides 763” denotes all the polypeptides of the present invention and also the polypeptides encoded by the polynucleotides of the present invention. The term “polypeptides 763” also denotes fusion proteins, recombinant proteins or chimeric proteins comprising these polypeptides. In the present description, the term “polypeptide” also denotes proteins and peptides, and also modified polypeptides.
[0041] The polypeptides of the invention are isolated or purified from their natural environment. The polypeptides may be prepared by various methods. These methods are in particular purification from natural sources, such as cells naturally expressing these polypeptides, production of recombinant polypeptides by suitable host cells and subsequent purification thereof, production by chemical synthesis or, finally, a combination of these various approaches. These various methods of production are well known to those skilled in the art. Thus, the polypeptides 763 of the present invention may be isolated from the fungi expressing polypeptides 763. Preferably, the polypeptides 763 of the present invention are isolated from recombinant host organisms expressing a heterologous polypeptide 763. These organisms are preferably chosen from bacteria, yeasts, fungi, animal cells or insect cells.
[0042] A subject of the present invention is a polypeptide comprising a polypeptide 763 of Magnaporthe grisea of SEQ ID No. 3. The invention also relates to polypeptides comprising a biologically active fragment or a homologue of the polypeptide 763 of SEQ ID No. 3.
[0043] In another embodiment, a subject of the present invention is a polypeptide comprising a polypeptide 763 of Neurospora crassa of SEQ ID No. 5. The invention also relates to polypeptides comprising a biologically active fragment or a homologue of the polypeptide 763 of SEQ ID No. 5.
[0044] The term “fragment” of a polypeptide denotes a polypeptide comprising part but not all of the polypeptide from which it is derived. The invention relates to a polypeptide comprising a fragment of at least 10, 15, 20, 25, 30, 35, 40, 50 100, 200 amino acids of a polypeptide of SEQ ID No. 3.
[0045] The term “biologically active fragment” denotes a fragment of a polypeptide which conserves the function of the polypeptide from which it is derived. The biologically active fragments of the polypeptide of SEQ ID No. 3 thus conserve the function of the polypeptide 763 of Magnaporthe grisea . These biologically active fragments therefore have activity of a transcription factor which is functional in fungi. Preferentially, this activity is essential to the pathogenesis of the fungus.
[0046] The term “homologue” denotes a polypeptide which may have a deletion, an addition or a substitution of at least one amino acid. A subject of the invention is a polypeptide having at least 75%, 80%, 85%, 90%, 95%, 98% and preferentially at least 99% of amino acids identical with a polypeptide of SEQ ID No. 3 or of SEQ ID No. 5. The methods for measuring and identifying homologies between polypeptides or proteins are known to those skilled in the art. The UWGCG package and the BESTFITT program may, for example, be used to calculate the homologies (Devereux et al., Nucleic Acid Res. 12, 387-395, 1984). The default parameters are preferably used.
[0047] Preferably, these homologous polypeptides conserve the same biological activity as the polypeptide 763 of Magnaporthe grisea of SEQ ID No. 3. Preferentially, these polypeptides therefore have a fungal transcription factor activity. Preferentially, this activity is essential to the pathogenesis of the fungus. In a preferred embodiment, these homologous polypeptides may be isolated from phytopathogenic fungi. Preferably, these polypeptides are expressed in phytopathogenic fungi at the beginning of plant infection
[0048] A subject of the invention is also a fusion polypeptide comprising a polypeptide 763 as described above fused to a reporter polypeptide. The reporter polypeptide allows rapid detection of the expression of a polypeptide 763 in a fungus or in another host organism. Among the polypeptides which may thus be fused with a polypeptide 763, mention will be made in particular of GFP (green fluorescent protein) and the GUS (β-glucuronidase) protein. These fusion proteins and their constructs are well known to those skilled in the art.
Expression Cassettes, Vectors and Host Organisms
[0049] Gene 763 can be expressed in various host organisms, such as bacteria, yeasts, fungi, animal cells or insect cells. Gene 763 can be expressed in a host organism under the control of the promoter 763 of the present invention or under the control of a heterologous promoter.
Expression Cassettes
[0050] According to an embodiment of the invention, a polynucleotide encoding a polypeptide 763 is inserted into an expression cassette using cloning techniques well known to those skilled in the art. This expression cassette comprises the elements required for the transcription and translation of the sequences encoding the polypeptide 763. Advantageously, this expression cassette comprises both elements for making a host cell produce a polypeptide 763 and elements required for regulating this expression. In a first embodiment, the expression cassettes according to the invention comprise, in the direction of transcription, a promoter which is functional in a host organism, gene 763 or the sequence encoding gene 763, and a sequence which is a terminator sequence in said host organism. Preferentially, the expression cassette comprises, in the direction of transcription, a promoter which is functional in a host organism, a polynucleotide chosen from the following polynucleotides:
a) a polynucleotide encoding the polypeptide 763 of SEQ ID No. 3 or encoding a biologically active fragment of the polypeptide 763 of SEQ ID No. 3; b) a polynucleotide, the sequence of which is included between position 17 and position 733 of SEQ ID No. 2; c) a polynucleotide of SEQ ID No. 1; d) a polynucleotide of SEQ ID No. 2; e) a polynucleotide encoding the polypeptide 763 of SEQ ID No. 5 or encoding a biologically active fragment of the polypeptide 763 of SEQ ID No. 5; f) a polynucleotide of SEQ ID No. 4; g) a polynucleotide homologous to a polynucleotide as defined in b), c), d) or f); h) a polynucleotide capable of specifically hybridizing to a polynucleotide as defined in b), c), d) or f);
and a sequence which is a terminator sequence in said host organism.
[0059] Any type of promoter sequence may be used in the expression cassettes according to the invention. The choice of promoter will in particular depend on the host organism chosen for expressing the gene of interest. Some promoters allow constitutive expression whereas other promoters are, on the contrary, inducible. Among the promoters which are functional in fungi, mention will be made in particular of that of Aspergillus nidulans glyceraldehyde-3-phosphate dehydrogenase (Roberts et al., Current Genet. 15:177-180, 1989). Among the promoters which are functional in bacteria, mention will be made in particular of the T7 bacteriophage RNA polymerase (Studier et al., Methods in enzymology 185:60-89, 1990) Among the promoters which are functional in yeasts, mention will be made in particular of that of the Gall gene (Elledge et al., Proc. Nat. Acad. Sciences, USA. 88:1731-1735, 1991) or the GAL4 and ADH promoters of S. cerevisiae . Among the promoters which are functional in insect cells, mention will be made in particular of the polyhedrin promoter of the baculovirus AcMNPV (Weyer et al., J. Gene. Virol. 72:2967-2974, 1991). Among the promoters which are functional in animal cells, mention will be made of the metallothionein promoter and viral and adenoviral promoters. All these promoters are described in the literature and are well known to those skilled in the art.
[0060] The promoter 763 may be used to express a heterologous gene in a host organism and in particular in fungi. A subject of the invention is therefore also expression cassettes comprising the promoter of a gene 763, functionally associated with a sequence encoding a heterologous protein, allowing expression of said protein in fungi. Preferably, the expression cassette according to the invention comprises, in the direction of transcription, a polynucleotide, the sequence of which is included between position 1 and position 705 of SEQ ID No. 1, or a biologically active fragment of the polynucleotide, the sequence of which is included between position 1 and position 705 of SEQ ID No. 1, the sequence encoding a heterologous polypeptide and terminator sequence which is functional in fungi. Any gene of interest may be expressed in a host organism under the control of a promoter 763. Preferably, the promoter 763 is used for expressing a heterologous gene in fungi. The activity of the promoter 763 under various conditions may be evaluated using a reporter gene such as the GUS (β-glucuronidase), GFP (green fluorescent protein), LUC (luciferase), CAT (chloramphenicol transferase) or β-galactosidase (lacZ) reporter gene.
[0061] In a preferred embodiment of the invention, the promoter 763 is functionally associated with the coding sequence of a marker gene. Expression of the marker gene allows the transformed organisms to be selected by virtue of their resistance to antibiotics or to herbicides for example. Mention will in particular be made of the coding sequences for a gene for tolerance to an antibiotic or a herbicide, such as the genes for resistance to hygromycin (hph: Punt et al., 1987), to bleomycin (ble: Drocourt, 1990) or to the herbicide bialaphos (Bar: Pall and Brunelli, 1993).
[0062] The expression cassettes according to the present invention may also include any other sequence required for expressing gene 763 or the heterologous gene, such as, for example, regulatory elements or signal sequences for addressing the polypeptide 763. Any regulatory sequence making it possible to increase the level of expression of the coding sequence inserted into said expression cassette may in particular be used. According to the invention, it is in particular possible to use, in combination with the promoter regulatory sequence, other regulatory sequences, which are located between the promoter and the coding sequence, such as transcription activators (enhancers). As a signal for membrane addressing in the host organisms, mention will in particular be made of that of protein A in bacteria (Nilsson et al., Methods in Enzymology 198:3, 1991).
[0063] A large variety of terminator sequences can be used in the expression cassettes according to the invention, these sequences allowing termination of transcription and polyadenylation of the mRNA. Any terminator sequence which is functional in the host organism selected may be used.
[0064] A subject of the present invention is also a polynucleotide comprising an expression cassette according to the invention; advantageously, the expression cassettes according to the present invention are inserted into a vector.
Vectors
[0065] The present invention therefore also relates to replication or expression vectors for transforming a host organism, comprising at least one polynucleotide 763 or an expression cassette according to the present invention. This vector may in particular consist of a plasmid, a cosmid, a bacteriophage or a virus, into which a polynucleotide 763 or an expression cassette according to the invention is inserted. The techniques for constructing these vectors and for inserting a polynucleotide of the invention into these vectors are well known to those skilled in the art. In general, any vector capable of maintaining itself, of self-replicating or of propagating in a host cell, and in particular in order to induce the expression of a polynucleotide or of a polypeptide, may be used. Advantageously, the vectors according to the invention comprise at least one origin of replication in order for them to replicate in a host organism. Preferably, the vectors of the invention also comprise at least one selectable marker, such as a gene for resistance to an antibiotic. Mention will in particular be made of vectors such as pBluescript (Stratagene, La Jolla, Calif.), pTrcHis (Invitrogen, La Jolla, Calif.) and baculovirus-derived expression vectors, such as those derived from the Autographica californica polyhedrovirus (AcMNPV). A preferred system combining a baculovirus and an insect cell is the pV111392 baculovirus/Sf21 cell system (Invitrogen, La Jolla, Calif.). For expression in animal cells, adenovirus-derived vectors are in particular used. Those skilled in the art will choose the suitable vectors in particular as a function of the host organism to be transformed and as a function of the transformation technique used. The methods for transforming host organisms are well known to those skilled in the art (Inoue et al., Gene 96:23-28, 1990; Fincham, Microbiological Reviews 53:148-170, 1989).
[0066] The vectors of the present invention are in particular used to transform a host organism for the purpose of replication of the vector and/or expression of a polypeptide 763 in said host organism. The invention relates to a method for preparing a polypeptide M763, comprising the following steps:
a host organism is transformed with an expression vector comprising an expression cassette according to the invention. the polypeptides M763 produced by the host organism are isolated.
[0069] The recombinant polypeptides 763 produced by a host organism transformed with a polynucleotide can be purified or isolated according to methods known to those skilled in the art. The polypeptides M763 can be expressed in a host organism in the form of fusion proteins. Mention will in particular be made of the vectors pGEX for expressing fusion proteins comprising glutathione S-transferase (GST). These fusion proteins are easily purified by adsorption on glutathione-agarose beads. The GST group can then be removed by digestion with protease Ma. Other systems for expressing and purifying fusion proteins are known to those skilled in the art.
Host Organisms
[0070] A subject of the present invention is also a method for transforming a host organism by integrating into said host organism at least one polynucleotide 763 or an expression cassette or a vector according to the invention. The polynucleotide may be integrated into the genome of the host organism or may replicate stably in the host organism. The methods for transforming host organisms are well known to those skilled in the art and widely described in the literature (Inoue et al., Gene 96:23-28, 1990; Fincham, Microbiological Reviews 53:148-170, 1989).
[0071] The present invention also relates to a host organism transformed with a polynucleotide 763, an expression cassette or a vector according to the invention. According to the invention, the term “host organism” is in particular intended to mean any lower or higher, unicellular or pluricellular organism, in particular chosen from bacteria, yeasts, fungi, animal cells and insect cells. Advantageously, the bacteria are chosen from Escherichia coli and Bacillus subtilis , the yeasts are chosen from Pichia pastoris and Saccharomyces cerevisae , the insect cells are chosen from Spodoptera frugiperda and Drosophila melanogaster , and the animal cells are chosen from CHOR, HeLa and COS cells.
[0072] The techniques for constructing vectors, for transforming host organisms and for expressing heterologous proteins in these organisms are widely described in the literature (Ausubel F. M. et al., “Current Protocols in Molecular Biology” Volumes 1 and 2, Greene Publishing Associates and Wiley-Interscience, 1989; T. Maniatis, E. F. Fritsch, J. Sambrook, Molecular Cloning A Laboratory Handbook, 1982).
[0073] The present invention also relates to the use of polynucleotides 763 and of polypeptides 763 for identifying genes involved in fungal pathogenesis and for identifying novel fungicidal molecules which inhibit fungal pathogenesis.
Inhibition of Fungal Pathogenesis
[0074] Fungi in which gene 763 is inactivated or inhibited exhibit a pathogenesis which is reduced by 95%. The invention relates to methods for inhibiting fungal pathogenesis by inactivating or inhibiting the expression of gene 763. Preferably, the fungi are chosen from Botrytis cinerea, Mycosphaerella graminicola, Stagnospora nodorum, Blumeria graminis, Colleotrichum lindemuthianum, Puccinia graminis, Leptosphaeria maculans, Fusarium oxysporum, Fusarium graminearum and Venturia inaequalis.
[0075] Preferably, the invention relates to methods for inhibiting the pathogenesis of a fungus, said methods comprising inhibiting the expression of a polynucleotide 763 according to the invention in said fungus, or inhibiting the expression of a polypeptide 1763 according to the invention in said fungus or inhibiting the biological activity of a polypeptide 763 according to the invention in said fungus. Preferably, this inhibition affects specifically the expression of gene 763 and the biological activity of the polypeptide 763. The invention does not therefore relate to the methods comprising the general inhibition of gene expression in the fungus. It will be understood that the inhibition of the expression of gene 763 may, however, lead to the inhibition of other genes.
[0076] Various methods well known to those skilled in the art may be used to inhibit fungal pathogenesis by inhibiting the expression of gene 763 in these fungi. In one embodiment of the invention, gene 763 is inactivated by insertional mutagenesis or by homologous recombination (gene replacement or “knock out” techniques). In another embodiment of the invention, the expression of a polypeptide 763 is inhibited by expressing an antisense polynucleotide of gene 763 in the fungi. In a third embodiment of the invention, the expression of gene 763 is inhibited by an inhibiting compound.
[0077] The level of expression of a polynucleotide 763 or of a polypeptide 763 in the fungi can be measured according to techniques described in the literature. Mention will in particular be made of Northern blotting, PCR and DNA arrays (DNA chips) for the polynucleotides and Western blotting for the polypeptides. These techniques are well known to those skilled in the art.
[0000] Identification of Novel Fungicidal Molecules which Inhibit Fungal Pathogenesis
[0078] Inactivation of gene 763 in Magnaporthe grisea , a pathogenic fungus of rice, leads to a 95% decrease in the pathogenesis of this fungus. Moreover, it has been possible to identify homologous genes in other fungi. Consequently, compounds which inhibit the expression of gene 763 or the activity of the polypeptide 763 in fungi can be used to inhibit fungal pathogenesis.
[0079] The invention therefore relates to methods for identifying compounds which inhibit fungal patho-genesis, comprising a step of identifying a compound which specifically inhibits the expression of a polynucleotide 763 in said fungus, or a step of identifying a compound which inhibits the expression of a polypeptide 763 in said fungus or a step of identifying a compound which inhibits the biological activity of a polypeptide 763 in said fungus.
[0080] Preferably, the fungi are chosen from Botrytis cinerea, Mycosphaerella graminicola, Stagnospora nodorum, Blumeria graminis, Colleotrichum lindemuthianum, Puccinia graminis, Leptosphaeria maculans, Fusarium oxysporum, Fusarium graminearum and Venturia inaequalis.
[0081] The polynucleotides 763, the polypeptides 763, the vectors and the host organisms of the present invention may thus be used in various screening assays in order to identify novel antifungal compounds.
[0000] Identification of Inhibitors which Bind to the Protein 763
[0082] Molecules which directly inhibit the activity of the polypeptide 763 might inhibit the pathogenesis of the fungus and lead to the development of novel fungicides
[0083] The invention therefore relates to a method for identifying compounds which inhibit fungal pathogenesis, comprising the following steps:
bringing said compound into contact with a polypeptide 763, and detecting the binding of said compound to said polypeptide; and
preferentially, the method also comprises a step in which it is determined whether said compound inhibits fungal pathogenesis.
[0086] Any method for preparing a polypeptide 763 and for purifying it or for isolating it may be used in the methods of the present invention.
[0087] Preferably, the polypeptide 763 is expressed in a heterologous expression system (for example bacterium, yeast, animal cell or insect cell) by means of a polynucleotide 763 according to the invention; the simplified purification of the polypeptide 763 then makes it possible to identify novel molecules which bind to the protein 763. Said molecules are identified using methods well known to those skilled in the art, in particular methods of physical detection of the binding of the compounds tested to the protein 763 (BIACORE system; Karlson & al., J. of Biomolecular Interaction Analysis, Special Issue Drug Discovery: 18-22).
Identification of Inhibitors of Gene 763 Expression Regulators
[0088] Molecules which inhibit the expression of gene 763 may also inhibit the pathogenesis of the fungus and lead to the development of novel fungicides. In the present invention, the expression “inhibition of the expression of gene 763” denotes the inhibition of the expression of a polynucleotide 763 and also the inhibition of the expression of a polypeptide 763 in host organisms, and preferentially in phytopathogenic fungi.
[0089] A subject of the invention is also a method for identifying compounds which inhibit fungal pathogenesis, comprising the following steps:
bringing said compound into contact with a host organism transformed with a polynucleotide or a vector according to the invention such that this host organism expresses a reporter gene under the control of the promoter of gene 763; and detecting the inhibition of the expression of said reporter gene.
[0092] Preferentially, the method also comprises a step in which it is determined whether said compound inhibits fungal pathogenesis.
[0093] The use of a polynucleotide according to the invention, comprising the promoter 763 associated with the coding sequence of a reporter gene (GUS or GFP for example) makes it possible to measure the promoter activity of the promoter 763 in a fungal cell or in a host cell. This method makes it possible to identify compounds which inhibit the activity of the promoter 763 and therefore the expression of gene 763 at the transcriptional level. A recombined strain comprising the above gene is thus used to identify molecules which inhibit the expression of gene 763, which manifests itself by inhibition of the expression of the reporter protein of the recombined strain under conditions for expression of gene 763. This type of assay is well known to those skilled in the art and described in the literature, in particular Axiotis et al. (1995. pp. 1-7 in Antifungal Agents: Discovery and Mode of Action. G. K. Dixon, L. G. Coppong and D. W. Hollomon, eds, BIOS Scientific Publisher Ltd. Oxford, UK).
[0094] In another embodiment, the invention relates to a method for identifying compounds which inhibit fungal pathogenesis, comprising the following steps:
bringing said compound into contact with a host organism transformed with a polynucleotide according to the invention or a vector according to the invention, said host organism expressing a polypeptide 763; and detecting the inhibition of the expression of said polypeptide 763.
[0097] Preferably, the polypeptide 763 is a fusion polypeptide comprising a reporter polypeptide such as GUS of GFP, the expression of which is easily measured. Preferentially, the method also comprises a step in which it is determined whether said compound inhibits fungal pathogenesis. This method makes it possible to identify compounds which inhibit the expression of gene 763 at the transcriptional level or at the translational level. A recombined strain expressing a polypeptide 763, and preferably a polypeptide 763 fused to a reporter, is thus used to identify molecules which inhibit the expression of gene 763, which manifests itself by inhibition of the expression of the polypeptide 763 of the recombined strain under the conditions for expression of gene 763.
[0098] The present invention therefore relates to a method for identifying compounds which inhibit fungal pathogenesis associated with expression of gene 763, said method consisting in subjecting a compound, or a mixture of compounds, to an assay suitable for identifying compounds which inhibit said fungal pathogenesis, and in selecting the compounds which react positively to said assay and, where appropriate, in isolating them and then in identifying them.
[0099] Preferentially, the suitable assay is an assay as defined above.
[0100] Preferably, a compound identified according to these methods is then tested for its antifungal properties and for its ability to inhibit the pathogenesis of the fungus for plants, according to methods known to those skilled in the art. Preferentially, the compound is evaluated using phenotypic tests, such as pathogenesis assays on leaves or on whole plants.
[0101] According to the invention, the term “compound” is intended to mean any chemical compound or mixture of chemical compounds, including peptides and proteins.
[0102] According to the invention, the expression “mixture of compounds” is understood to mean at least two different compounds, such as, for example, the (dia)stereoisomers of a molecule, mixtures of natural origin derived from the extraction of biological material (plants, plant tissues, bacterial cultures, yeast or fungal cultures, insects, animal tissues, etc.) or reaction mixtures which are unpurified or totally or partly purified, or else mixtures of products derived from combinatorial chemistry techniques.
[0103] Finally, the present invention relates to novel compounds which inhibit fungal pathogenesis associated with expression of gene 763, in particular the compounds identified by the method according to the invention and/or the compounds derived from the compounds identified by the method according to the invention.
[0104] Preferentially, the compounds which inhibit fungal pathogenesis associated with expression of gene 763 are not general enzyme inhibitors. Also preferentially, the compounds according to the invention are not compounds already known to have fungicidal activity and/or activity on fungal pathogenesis.
[0105] A subject of the invention is also a method for treating plants against a phytopathogenic fungus, characterized in that it comprises treating said plants with a compound identified by a method according to the invention.
[0106] The present invention also relates to a method for preparing a compound which is an inhibitor of fungal pathogenesis, said method comprising the steps of identifying a compound which inhibits fungal pathogenesis associated with the expression of gene 763, by the identification method according to the invention, and then preparing said identified compound by the usual methods of chemical synthesis, of enzymatic synthesis and/or of extraction of biological material. The step of preparing the compound may be preceded, where appropriate, by an “optimization” step by which a compound derived from the compound identified by the identification method according to the invention is identified, said derived compound then being prepared by the usual methods.
[0107] The examples below make it possible to illustrate the invention without, however, seeking to limit the scope thereof.
[0108] All the methods or operations described below in these examples are given by way of examples and correspond to a choice, made from the various methods available for achieving the same result. This choice has no bearing on the quality of the result and, consequently, any suitable method may be used by those skilled in the art in order to achieve the same result. Most of the DNA fragment engineering methods are described in “Current Protocols in Molecular Biology” Volumes 1 and 2, F. M. Ausubel et al., published by Greene Publishing Associates and Wiley-Interscience (1989), or in Molecular Cloning, T. Maniatis, E. F. Fritsch and J. Sambrook (1982). The methods specific for fungi are described in Sweigard et al. (Fungal Genetics Newsletter, 44:52-53, 1997) for the fungal transformation vectors used, in Orbach (Gene 150:159-162, 1994) for constructing a cosmid library, in Sweigard et al. (Fungal Genetics Newsletter, 37:4-5, 1990) for preparing fungal genomic DNAs, and in Agnan et al. (Fungal Genetics and Biology, 21:292-301, 1997).
DESCRIPTION OF THE FIGURES
[0109] FIG. 1 : Autoradiogram of hybridization, with a probe pAN7.1, of the transfer onto nylon membranes of genomic DNA digestions of the mutant 763. (E:EcoR1; A:ApaI; C:ClaI; K:KpnI).
[0110] FIG. 2 : “Plasmid rescue” in the mutant 763. Genomic DNA of the mutant 763 (in bold) with insertion site of the plasmid. The positions of the EcoRI and KpnI sites on the genomic DNA are arbitrary.
[0111] FIG. 3 : Insertion locus of the plasmid pAN7.1 and BglII-XhoI restriction fragment (6 kb) complementing the mutant m763. The position of the genomic probe (0.4 kb) derived from PRK763 is indicated in bold. The arrows indicate the position of the PCR primers for amplifying the point of insertion of the plasmid into the wild-type strain. The point of insertion of the plasmid pAN7.1 is also indicated.
[0112] FIG. 4 : Identification of a basic “leucine zipper” domain. Consensus obtained by alignment of the sequence of the protein P763 with those of the transcription factors YAP-1 and GCN4 of Saccharomyces cerevisiae and MEAB of Aspergillus nidulans . This domain comprises a basic domain (A) and a “leucine zipper” domain per se (B).
[0113] FIG. 5 : Consensus obtained by alignment of the sequence of the protein 763 of Magnaporthe grisea with those of the transcription factors YAP-1 and GCN4 of Saccharomyces cerevisiae and CPC-1 of Neurospora crassa.
[0114] FIG. 6 : Autoradiograms of hybridization, with a probe consisting of the cDNA of gene 763, of Southern membranes of the products of RT-PCR and nested-PCR amplification of the mRNA of this gene under various conditions.
[0115] FIG. 7 : Alignment of the protein 763 of Magnaporthe grisea and of the homologous protein of Neurospora crassa.
[0116] Alignment produced using the clustal-W program. (*: identical amino acids).
EXAMPLES
[0117] The strategy employed to achieve the identification and characterization of gene 763 essential to the pathogenesis of M. grisea comprised two main points:
1) Inactivation of a gene essential to pathogenesis by random insertion into its nucleotide sequence of a foreign DNA fragment (insertional muta-genesis). 2) Recovery and characterization of the fungal nucleotide sequence thus modified, and then demonstration of its involvement in the pathogenesis of the fungus with respect to rice and to barley.
[0120] The methodological steps to be successively surmounted are as follows:
1) Obtaining a collection of fungal isolates having randomly integrated a foreign DNA fragment into their genome (transformants). In this case, the foreign DNA is a plasmid comprising the hph gene of Escherichia coli , which allowed them to be selected on the basis of hygromycin resistance. It was introduced into the fungal genome by protoplast transformation. 2) Searching for transformants which are nonpatho-genic with respect to rice and to barley, among the collection (pathogenesis mutants). The criterion selected for nonpathogenesis of a transformant was the inability to cause foliar lesions subsequent to inoculation of spores of this transformant into rice and barley plants. 3) Genetically demonstrating the inactivation of a pathogenesis gene by the plasmid in the mutants incapable of infecting rice and barley. This involved establishing complete genetic linkage between the hygromycin-resistance characteristic, which reflects the presence of the plasmid in the genome of the mutant, and that of nonpathogenesis, which reflects the inactivation of a gene essential to the infectious capacity of the fungus. This degree of linkage was evaluated by analysis of segregation of the hygromycin-resistance and nonpathogenesis characteristics in the descendents of a cross between the mutant studied and a wild-type strain pathogenic with respect to rice and to barley and having a mating type compatible with that of the mutant. 4) Recovering the genomic region of the fungus at which the insertion of the mutating plasmid occurred. The principle consisted in isolating a DNA fragment of the mutant comprising both plasmid and genomic sequences, detectable by virtue of a hybridization experiment with a probe of plasmid origin. The genomic component included in this fragment was then used to isolate the complete wild-type genomic region according to the same principle. 5) Demonstrating that the genomic region next to the point of insertion of the plasmid contains the pathogenesis gene. If the pathogenesis gene sought is in the genomic region next to the point of insertion of the plasmid, the introduction thereof into the genome of the mutant isolate, using a plasmid vector comprising another selectable marker, should make it possible to restore pathogenesis by complementation of the function made deficient by insertion of the first plasmid. Proof of this is provided if the spores of at least one transformant obtained through this experiment are capable of causing as many foliar lesions as the wild-type strain. 6) Characterizing the genomic sequence of the fungus in the proximity of the point of insertion of the plasmid. The product from sequencing the genomic region next to the point of insertion of the plasmid is analyzed with sequence processing programs, so as to attempt to demonstrate therein a nucleotide sequence capable of being translated into peptide sequence (open reading frame). This search is carried out on the basis of searching for consensus signals for initiation and termination of translation to protein. Proof of the existence of an open reading frame (and therefore of a gene) in this region was provided by cloning the corresponding transcriptional unit, by screening a library of DNAs complementary to messenger RNAs (cUNAs) with a probe produced from a fragment of this region. The sequence of this cDNA makes it possible to determine with precision the size and the primary sequence of the corresponding protein, and also the position of possible introns in the genomic sequence of the gene.
Example 1
Insertional Mutagenesis
[0127] Protoplast transformation with an integrative plasmid carrying a selectable marker was used as an insertional mutagenesis tool in order to search for the pathogenesis genes of the rice-parasite ascomycete fungus Magnaporthe grisea . The conditions for culturing, for obtaining protoplasts, for transformation and also for purifying and storing Magnaporthe grisea transformants are described by Silue et al. (Physiol. Mol. Plant. Pathol., 53, 239-251, 1998). The transformation was carried out with 1 μg of plasmid pAN7.1 (Punt et al., Gene 78: 147-156), 1987) and 10 7 protoplasts of the M. grisea strain P1.2. This strain originates from the collection of the phytopathology laboratory of the CIRAD [International Center for Cooperation in Agronomic Research for Development] in Montpellier. The transformants were selected by incorporating hygromycin into the agar culture media, at the concentrations of 240 ppm for the primary selection medium and of 120 ppm for the secondary selection medium.
Example 2
Screening the Collection of Transformants and Identifying the Nonpathogenic Mutant 763
A) Pathogenesis Assays on Leaves Under Survival Conditions
[0128] The pathogenesis assays were carried out on two varieties of rice, Maratelli and Sariceltick, and one variety of barley, Express. Maratelli are varieties which are very sensitive to blast disease and which do not have genes for resistance to the strain 21.2. The barley varieties are extremely sensitive to blast disease. The rice was grown at 25° C. during the day and 15° C. at night with a hygrometry of greater than 70%, the barley was grown under cold conditions (20-22° C.) Rice and barley leaf fragments (2.5 cm) were removed from the median part of the youngest leaf of plants about twenty days old. These fragments were placed in multicompartment dishes containing water with 1% agar supplemented with 2 mg/l of kinetin, a medium which allows them to survive for 14 days. It is important to note that rice develops a strong physiological resistance to blast disease during periods of great heat. This resistance may be attenuated by giving the plants nitrogen-based fertilizer: two waterings with a solution of ammonium sulfate at 5 g/m 2 , one week apart. The second watering takes place 2 to 3 days before inoculation.
[0129] The conditions for sporulation and for preparing M. grisea spore inoculum are described by Silué et al. (mentioned above). The inoculation was performed using a wet cotton-wool bud soaked in a suspension of spores and passed over the leaf fragments under survival conditions. The amount of spores deposited was estimated by depositing a drop of the suspension onto a glass slide. The symptoms were observed after 4-7 days of incubation at 24° C., 100% hygrometry. Each transformant was tested on four rice leaf fragments of each variety and four of barley during the first screening. The transformant 763 shows a decrease in pathogenesis quantified at 95% of the number of lesions caused by the wild-type strain. The transformant 763 was inoculated a second time, in order to confirm its phenotype, with a suspension of spores having a concentration adjusted to 10 5 spores per ml. The results are given in the table below.
[0000]
TABLE 1
Penetration of the mutant 763 into barley leaves
Inoculation of barley leaves with drops of 35 microliters
containing spores (500 000 spores/ml)
Exp. 1
48 h after inoculation, many surface appressoria, few
penetrations, some infectious hyphae visible,
6 days, no visible lesion, brown coloration at the point of
contact of the drop
Exp. 2
48 h after inoculation, many surface appressoria, penetration
not observed
4 days, no visible lesion, brown coloration at the point of
contact of the drop
Exp. 3
48 h after inoculation, many surface appressoria, few
penetrations, infectious hyphae visible in the leaf,
colonization greatly slowed compared to P12
B) Pathogenesis Assays on Whole Plants
[0130] In order to confirm the phenotype of the nonpathogenic mutant 763 detected by inoculation of leaves under survival conditions, the department of phytopathology of the CIRAD at Montpellier performed inoculations of whole plants with the spores of this mutant. The two rice cultivars sensitive to the P1.2 strain, Maratelli and Sariceltick were sown and cultured under glass. Three nitrogen applications were performed during the first three weeks of culturing (at 5, 10 and 20 days after sowing). The inoculation by spraying a suspension of spores takes place 10 to 15 days after giving nitrogen for the last time, depending on the degree of maturity of the plants. The spore concentration was determined by counting with a Thoma cell and adjusted to a value of 20 000 spores/ml. The suspensions of spores of the mutant 763 and of the nontransformed strain P1.2 were sprayed onto thirty plants, in a proportion of 1 ml of spore suspension per plant, with an aerograph. One leaf from each of these plants was collected for counting the number of lesionsr after they had developed (5 to 7 days). A 93% decrease in pathogenesis was also observed on whole plants (see table below).
[0000]
TABLE 2
Spraying a spore suspension onto whole
plants (rice, variety Sariceltick)
Decrease
compared
P12 (wild-type strain)
Mutant 763
to P12
Exp. 1
Spores
42 lesions per leaf
7 lesions per leaf
−85%
25 000 sp/ml
lesion size: 3.5 mm 2
lesion size: 0.5 mm 2
−85%
Exp. 2
Spores
30 lesions per leaf
2 lesions per leaf
−93%
100 000 sp/ml
Example 3
Phenotypic Analysis of the Mutant 763
[0131] The mutant 763 is affected by a decrease in pathogenesis quantified at 93% of the number of lesions caused by the wild-type strain, without its ability to sporulate being lessened. In addition, while the rare lesions observed were clearly visible and made up of a necrotic area surrounded by a brownish border (typical symptom of blast disease), they were all small in size and nonsporulating, contrary to those caused by the wild-type strain (−90% at the surface). An infection assay on injured leaves shows that the progression of the hyphae of this mutant, in planta, remains limited to the area of injury. Cytological analysis of the infection in this mutant shows that the mutant manages to penetrate through the epidermal cell wall in barley, but it is then rapidly blocked in its progression.
[0132] The physiology and morphology of the conidia and of the mycelium of the transformant 763 are apparently normal.
[0133] Its ability to differentiate appressoria on barley epidermis, as on artificial hydrophobic surfaces (PVC, Teflon, PET), is not different from that of the wild-type strain.
[0134] The growth of this mutant was also studied in the presence of salts and drugs which interfere with assimilation of nitrogen compounds. This involved determining whether it exhibited the phenotype of loss of metabolic repression of nitrogen, a characteristic of the mutant meaB of Aspergillus nidulans (see later, molecular analysis; Polley and Caddick, 1996). In this fungus, the metabolic repression of nitrogen results, in the presence of ammonium or of L-glutamine, in inhibition of the genes required for acquiring and using other nitrogen sources. The mutation meaB is characterized by its resistance to methylammonium (a toxic inducer of metabolic repression of nitrogen) but also by its resistance to parafluorophenylalanine and by its hypersensitivity to nitric toxicity. The mutant 763 does not have a phenotype different from that of the wild-type strain under all the conditions tested. 763 also grows normally on minimum medium (MM).
Example 4
Genetic and Molecular Analysis of the Mutant 763
[0135] 20 ascospores at random and a tetrad derived from the cross M4×763 were analyzed. The results of this analysis appear in the table below and show that hygromycin resistance cosegregates with loss of pathogenic capacity: the mutated pathogenesis gene is tagged with the plasmid pAN7.1 in 763.
[0000]
TABLE 3
Analysis of the descendents of the cross M4 × 763
Ascospore
Hyg.
Path.
Parenteral tetrad
1
s
+
2
s
+
3
s
+
4
s
+
5
R
−
6
R
−
7
R
−
8
N.D
N.D.
Ascospores at random
1
s
+
2
N.D.
N.D.
3
R
−
4
R
−
5
R
−
6
R
−
7
R
−
8
S
+
9
R
−
10
R
−
11
R
−
12
s
+
13
s
+
14
s
+
15
s
+
16
R
−
17
R
−
18
R
−
19
s
+
20
s
+
[0136] The number of copies of the plasmid pAN7.1 present in the genome of this transformant and the relative position of the point of integration were determined by hybridization with a plasmid probe (see FIG. 1 ). Three types of restriction enzyme were used depending on the number of cleavages desired: EcoRI (2 cleavages); BamHI (1 cleavage); ApaI, ClaI and KpnI (no cleavage). The hybridization profiles of the restriction fragments obtained show that this transformant comprises only one copy of the plasmid (3 EcoRI fragments, a single fragment for BamHI, ApaI, ClaI and KpnI). Moreover, the single BamHI hybridization fragment is greater than 6.75 kb in size. This indicates that the copy of the plasmid integrated into the genome of this transformant does not possess at its ends the two BamHI sites expected subsequent to transformation in the presence of this restriction enzyme. According to the analysis performed on many transformants derived from REMI transformations, it is probable that the integration of the plasmid led to short deletions in one or in the two sticky ends of the plasmid BamHI site, thus creating no BamHI restriction site at the junctions between the plasmid DNA and the genomic DNA of the transformant. With regard to the digestions with the enzymes which do not cleave in the sequence of pAN7.1 (ApaI, ClaI and KpnI), the smallest restriction fragment containing the entire plasmid was obtained in the lane corresponding to the KpnI digestion (11 kb in size). An additional experiment consisting of hybridization of SspI restriction fragments of the genomic DNA of the transformant 763 with a pUC19 probe was able to show that the sequences of the origin of replication of the plasmid in E. coli and of the ampicillin resistance gene were intact.
Example 5
Cloning and Characterization of the Pathogenesis Gene 763
[0137] The “plasmid rescue” technique (Timberlake, 1991) was used to clone the genomic regions located at the point of insertion of the plasmid. Due to its small size, the 11 kb KpnI fragment identified in the molecular analysis of the mutant was chosen to carry out this experiment ( FIG. 2 ). A restriction analysis of the plasmid DNA of 4 ampicillin-resistant colonies obtained was performed. A colony bearing the expected plasmid (PRK763) was streaked and multiplied for the purpose of a DNA maxi preparation. An NdeI-SspI genomic DNA fragment of PRK763, 0.4 kb in size, located subsequent to sequencing the regions of genomic origin of this plasmid, was used to probe the cosmid library of the strain 96/0/76. The cosmids which hybridized with this fragment were isolated (21C7 and 35F3).
[0138] A 6 kb XhoI-BglII restriction fragment of the cosmid 35F3 which hybridizes with the NdeI-SspI restriction fragment of PRK763 was cloned into the plasmid pCB1265 ( FIG. 3 ). This construct, called pC763 was introduced into the genome of the mutant 763 by protoplast transformation. A pathogenesis assay on detached leaves showed that the phosphinothricin-resistant transformants obtained have the same degree of virulence as the wild-type strain.
[0139] The library of complementary DNAs from the messenger RNAs of genes expressed in a culture in complete liquid medium was screened with the NdeI-SspI fragment of PRK763. Two types of clone approximately 2 kb long were recovered. One was shorter than the other by 113 bp at its 5′ end, but 16 bp longer at its 3′ end, this being just before the terminal polyadenylated sequence. This polyadenylated sequence was present at the 3′ ends of the two types of clone isolated. Comparison of this cDNA sequence with that of the corresponding wild-type genomic DNA made it possible to demonstrate 3 introns of, respectively, 153, 78 and 108 pb. The positions of the translation initiation and termination signals in the cDNA sequence define an open reading frame 714 pb long. It begins 25 bp from the 5′ end of the sequence of the longest cDNA clone and ends 1.22 kb from the 3′ end of the sequence of this same clone, This long 3′-terminal untranslated sequence comprises many potential termination signals in the three possible reading frames.
[0140] The search for proteins with sequences homologous to that of P763 was carried out with the sequence alignment program BLASTP 2.0.8 (Altschul et al., 1997) in all the available databases using the default parameters. The only proteins which exhibit a significant degree of homology with the pathogenesis protein 763 of Magnaporthe grisea are the putative transcription factor MEAB of Aspergillus nidulans and also the transcription factors GCN4 and YAP1 of Saccharomyces cerevisiae.
[0141] MEAB is thought to be involved in the control of nitrogen assimilation depending on the nature of the available sources of this element (Polley and Caddick, FEBS letters 388:200-205, 1996). By virtue of its sequence, MEAB is related to the family of eukaryotic transcription factors of the bZIP type, composed of a dominant basic sequence-specific DNA binding motif following by another termed “leucine zipper motif”, required for dimerization of the protein. The degree of similarity between P763 and MEAB is at a maximum in the amino-terminal portion of their sequences, that corresponding to the bZIP domain. Apart from this region, the MEAB sequence is longer (400 AA versus 238 in P763) and bears little resemblance to that of P763 in its carboxy-terminal portion ( FIG. 4 ).
[0000]
TABLE 4
Search for proteins homologous to the deduced
protein of gene 763 (Blast P version 2.0.8)
% identity and homology at the level of
Score E
the b-ZIP domain (63 amino acids)
0.00009
38% and 54%
MeaB putative transcription
factor of A. nidulans with b-ZIP
0.002
31% and 55%
YAP1, transcription factor of
S. cerevisae with b-ZIP
0.002
40% and 55%
GCN4, transcription factor of
S. cerevisae with b-ZIP
[0142] The phenotypic analysis of the mutant 763 as a function of its behavior with respect to several drugs which interfere with nitrogen metabolism leads to the notion that the gene tagged with the plasmid in the mutant 763 is not the equivalent of MEAB in Magnaporthe grisea.
[0143] The sequence of the bZIP domain of P763 aligns partially in the same search with those of two transcription factors of Saccharomyces cerevisiae , GCN4 (protein regulating expression of amino acid biosynthesis genes; Hinnebusch, PNAS 81:6442-6446, 1984) and YAP1 (activator of transcription of genes for cellular defense against oxidative stress; Schnell et al., Curr. Genet. 21(4-5):269-73 1992), and with the CPC-1 gene of Neurospora crassa ( FIG. 5 ). Genes with a sequence homologous to that of the GCN4 gene were identified in the filamental fungi Neurospora crassa (Paluh et al., PNAS 85 (11) 3728-3732, 1988) with the CPC-1 gene and Cryphonectria parasitica (Wang et al., Fungal Genet. Biol. 23(1):81-94, 1998), and are different from gene 763 although related.
Example 6
Expression of the Pathogenesis Gene 763
[0144] A Northern blot prepared with 10 μg of RNAs extracted from samples of mycelium grown under several conditions (liquid culture in complete medium or in minimum medium) was hybridized, unsuccessfully, with a probe corresponding to the sequence of the cDNA of gene 763.
[0145] An RT-PCR experiment was carried out with primers located on both sides of the putative translation termination signal (defined by virtue of the analysis of the cDNA sequence) and 5 μg of total RNA extracted from mycelium from a liquid culture in complete medium. The amplification product, detected by hybridation with a probe 763, was cloned and sequenced. It shows no differences in size or in sequence with the cDNA clones isolated previously, in particular in the portion corresponding to the untranslated 3′ sequence of the messenger RNA of the gene.
[0146] A nested RT-PCR experiment was carried out with 5 μg of RNA from infected barley leaves extracted 20 hours after inoculation and a secondary amplification was performed with a second pair of internal primers. An amplification product was detected by hybridization with a probe 763, revealing expression of this gene during the early steps of host colonization ( FIG. 6 ). | The invention concerns a novel nucleic acid fragment of the genome of rice pathogenic fungus Magnaporthe grisea comprising a gene coding for a protein (hereafter referred to as gene 763) whereof the presence and integrity are indispensable for pathogenesis of said fungus with respect to rice and barley. The invention also concerns the promoter of said gene, the gene coding for protein 763, protein 763 and uses thereof for identifying potential biological targets for novel fungicide molecules and for isolating genes coding for proteins controlling biochemical functions essential to the pathogenesis of the fungus Magnaporthe grisea with respect to rice and barley. The invention further concerns compounds inhibiting pathogenesis of fungi related to the expression of gene 763. | 2 |
FIELD OF THE INVENTION
[0001] The present invention relates to a process for the synthesis of an aliphatic cyclic amine. More particularly, the present invention relates to amino cyclization of terminal diols. In particular this invention relates to a process for the selective synthesis of cyclic imines by the amino cyclization of a hydrocarbons having from four to six carbons and which are characterized by two hydroxy groups in the terminal positions to yield a cyclic imine.
BACKGROUND OF THE INVENTION
[0002] 3-Methylpiperidine is used as a vulcanization accelerator and as an additive to lubricant oil and 3-Methylpyridine is used both as a solvent and as an intermediate in the preparation of nicotinic acid. Cyclic amines are important compounds in the synthesis of drugs and for making of various reagents. Hexamethyleneimine is an important compound which is useful as an intermediate material for pharmaceuticals and agricultural chemicals, and also finds a wide range of applications as rubber vulcanization accelerators and other rubber chemicals, they are ingredients for textile lubricants, antistatic agents and finishing agents, corrosion inhibitors for metals, and modifiers or crosslinking agents for resins.
[0003] PCT application WO 90/00546 discloses the preparation of mixtures of 3-methylpiperidine and 3-methylpyridine starting from 2-methyl-1,5-diamino pentane by passing the gaseous starting material over a catalyst comprising metal oxides at 500° C.-600° C. Preferred catalysts are copper chromite, molybdenumoxide and vanadium oxide. These catalysts are preferably applied to a support. Depending on the reaction temperature, the ratio between piperidine and pyridine can be shifted to one or the other side. This patent specification also mentions the possibility of using acidic oxides, such as SiO 2 or silicon aluminium oxides, without further additives as catalysts. However, the yields achieved in this way are only moderate. No information is given on the catalyst activity over extended operating times.
[0004] U.S. Pat. No. 3,903,079 discloses a process for the cycloammonolysis of disubstituted alkanes containing primary amino and/or hydroxyl groups. The catalyst used is a metal aluminosilicate molecular sieve. Preferred metals are copper, palladium, manganese, nickel and chromium. The reaction was carried out in the presence of ammonia. The yields obtained were moderate. A yield of 75% was achieved in the preparation of piperidine from 1,5-pentanediol.
[0005] However, hexamethyleneimine has been obtained in small quantities from by-products which occur in the production of hexamethylenediamine by catalytic hydrogenation of adiponitrile or in the production of hexamethylenediamine by catalytic ammonolysis of 1,6-hexanediol. It has also been reported in Journal of the Chemical Society of Japan, Vol. 82, page 1701 (1961) that hexamethyleneimine was obtained in a yield of about 10% by heating hexamethylenediamine together with Raney nickel at 160° C. to 170° C., but a greater part of the product consisted of a resinous product or tar.
[0006] Chemische Berichte, Vol 96, page 924 (1963) also discloses that by heating hexamethylene diamine together with Raney nickel at 142° C.-143° C. in a solvent such as benzene, xylene or mesitylene, hexamethyleneimine is obtained in a yield of 24 to 38% (as the picrate salt), but at the same time, 1,6-bis-hexamethyleneiminohexane is formed in a yield of 12 to 47% (as the picrate salt). Furthermore, Canadian Pat. No. 920,606 (1973) discloses that hexamethyleneimine is obtained in a selectivity of 47 to 87% by contacting hexa methylenediamine with a hydrogenation catalyst at 150° C. to 250° C. in the presence of hydrogen. However, since the conversion of hexamethylenediamine is as low as 17 to 44%, a large quantity of unreacted hexamethylenediamine must be recovered by distillation. It is also necessary to reduce the amounts of by-products by adding hydrogen and ammonia during the reaction.
[0007] In an article titled “Equilibrium Conditions for Amination of Alcohols and Carbonyl Compounds”, Ind. Eng. Chem. Prod. Res. Develop., 11, 3, 333-337 (1972), Josef Pasek et al. described the influence of pressure, temperature, and initial composition on the equilibrium content of primary, secondary, and tertiary amines and unsaturated compounds.
[0008] In Catalysis of Organic Reactions, Blackburn, D. W., ed., 1990, at Chapter 14, M. Ford et al. review the selective synthesis of mixed alkyl amines by amine-alcohol reactions over hydrogen phosphate.
[0009] The amination of alcohols, aldehydes, and ketones using catalysts containing nickel, copper, or both, has been also been described, for example, in U.S. Pat. Nos. 3,520,933; 4,153,581; 4,152,353; and 4,409,399. These patents relates to selective production of diamines. U.S. Pat. No. 3,270,059 discloses the production of diaminoalkanes by passing an alkanediol, alkanolamine, alkylene oxide, or alkyleneimine along with either ammonia or an alkylamine in the presence of hydrogen and at an elevated temperature over a catalyst which contains sintered cobalt or nickel. The sintering process requires extra steps and high temperatures.
[0010] U.S. Pat. No. 4,290,946 discloses the synthesis of hexamethyleneimine from the deamino cyclisation of hexamethelene diamine over the raney nickel catayst in liquid phase but it suffers from the use of ammonia and hydrogen to reduce the catalysts prior to use it.
[0011] The amination of terminal diols to corresponding diamines is a known art over the metal oxides or on supported catalysts. But they suffer to yield cyclic imines by deamination and to avoid this they require to be carried out in presence of hydrogen gas. From the foregoing references it appears there that is a need in the art for an improved method of selectively producing cyclic imines by the amination of diols instead of diamines It would be very desirable in the art if a process were available for aminating a diol which is available in large volumes. This would provide an attractive route to an added-value commodity chemical.
OBJECTS OF THE INVENTION
[0012] The main object of the present invention is to provide a process for the preparation cyclic amines from diols which can be carried out on a commercial scale and achieves high yields. The catalyst activity should be maintained over long times.
SUMMARY OF THE INVENTION
[0013] The present invention relates to a process whrein high conversion of pentane diol, hexane diol and a high yield of piperidine and hexamethylenediamine respectively is maintained in the amination reaction of diol by inhibiting the formation of diamines and amino alcohols as by-products. These diamines find large volume applications in polyamide resins as monomer/comonomers, as well as price-competitive usage in lube oils, epoties, hot melt adhesives, and surfactants. They are also be useful in fuel additives, chelating agents, fungicides, and plastic lubricants.
[0014] Accordingly, the present invention relates to a process for the synthesis of an aliphatic cyclic imine having four to six carbons, said process comprising introducing into a reactor one or more C 4 to C 6 dihydric alcohols wherein the hydroxyl groups are in terminal positions reacting said C 4 to C 6 dihydric alcohol in a solvent and in the presence of excess ammonia in the presence of a metal containing ZSM-5 catalyst at a temperature in the range of 250° C. to 400° C. and weight hourly space velocity in the range of 0.25 to 1.00 h −1 .
[0015] In one embodiment of the invention, the dihydric alcohol used is 1,4-Butane diol to obtain pyrrolidine or pyrrole.
[0016] In one embodiment of the invention, the dihydric alcohol used is 1,5-Pentane diol to obtain piperidine or pyridine.
[0017] In one embodiment of the invention, the dihydric alcohol used is 1,6-hexane diol to obtain hexamethylene imine.
[0018] In one embodiment of the invention, the solvent is selected from the group consisting of alcohols, ethers and water.
[0019] In one embodiment of the invention, the diol is introduced into the reactor in aqueous solution.
[0020] In one embodiment of the invention, the molar ratio of ammonia to hydroxyl groups is 5 to 100.
[0021] In one embodiment of the invention, the metal amount impregnated on the catalyst ZSM-5 is in the range of 1 to 10 wt %.
[0022] In one embodiment of the invention, the Si/Al ratio of ZSM-5 catalyst is in the range of 15 to 140.
[0023] In one embodiment of the invention, one or more promoters selected from the group consisting of Group VIII and Group VIB of the Periodic Table are used.
[0024] In one embodiment of the invention, the promoters are selected from the group consisting of iron, copper, manganese, nickel, cobalt, molybdenum, lanthanum and chromium.
[0025] In one embodiment of the invention, the volume ratio of diol to solvent is in the range of 1:1 to 1:5.
[0026] In one embodiment, the invention relates to a hydroamination process which comprises reacting a diol characterized by four to six carbons, preferably 1,5-pentane diol with excess ammonia in the presence of a ZSM-5 catalyst which incorporates at least one metal selected from the group consisting of nickel and cobalt, or mixtures thereof, optionally supported, or as a bulk-metal catalyst, at a temperature of at least 250° C.
[0027] In one embodiment of the invention the cyclo amination exhibits good selectivity for the desired cyclic amine and is conducted batchwise.
[0028] In another embodiment of the invention, the reactants include diols having four to six carbons and any mixtures thereof
[0029] In a further embodiment of the invention, the reactants are selected from 1,4-butanediol, 1,5-pentanedioland and 1,6-hexane diol.
[0030] In the preferred embodiment this invention provides a process for the selective amino cyclization of 1,5-pentane diol to yield piperidine and its homologues in one step with greater than 95% conversions and higher selectivity towards the piperidine was achieved.
DETAILED DESCRIPTION OF THE INVENTION
[0031] Cyclic imines of four to six carbons are prepared in one step from a diol, preferably in a solvent, in the presence of excess ammonia and modified ZSM-5 catalyst, at a temperature of at least 250° C. and compounds were analysed by GC and GC mass.
[0032] The amino cyclization of 1,5-pentanediol was carried out M-ZSM5 where M is from the group of elements (H, Cr, Fe, Cu, Mn, La, Pb).
[0033] The catalyst used in this invention is a modified ZSM-5 catalyst with metal ion incorporated thereon by impregnation method or ion exchange method. The ZSM-5 catalyst can be synthesized by the reported literature using tripropylamine as template, ludox silica and aluminium isopropoxide as the source of silica and aluminium. Or a commercial catalyst available from Conteka Swedan. The catalyst was tabletted by tableting machine and made to 18-30 mesh, calcined at 500° C. for several hours to get H form of the zeolite and then soaked in the metal solution of 1 to 10 wt % of metal salt (salt may be from nitrtates, carbonates, actates or any other organic complex) for several hours then the water was evaporated. And further the catalyst was calcined at 400 to 450° C. to expel the low boilers and strengthern the catalyst.
[0034] All three classes of amines were identified through a combination of GC and GC-MS/IR techniques. The feedstock used in the practice of this invention s rises a terminal diol having from four to six carbons such as 1,4 butanediol, 1,5-pentane diol and 1,6-hexanediol.
[0035] In the one-step process of this invention, the reaction takes place in the presence of excess ammonia. The nitrogen source is required to be ammonia, preferably in gaseous form. The amination conditions to be utilized suitably include the use of from 5 to 50 moles of ammonia per hydroxyl equivalent of feedstock.
[0036] A suitable catalyst comprises at least one Group VIII metal, optionally on a support. Promoters may also be used. Suitable metals include cobalt, nickel, copper, manganese, lead, zirconium and molybdenum. Particularly effective catalyst is Cu or Ni modified zeolite.
[0037] The catalyst used without the promoters are also effective for the amino cyclization. The Si/Al ratio of the supported ZSM-5 catalyst varies from 15 to 140.
[0038] The catalyst is preferably introduced into the reaction zone initially. The temperature for the one-step process should be at least about 300° C. A suitable range is from about 250° C. to about 400° C. The preferred range varies depending on the chain length of the diol.
[0039] When the reaction is conducted on a continuous basis using the described nickel or cobalt catalysts liquid feed rates may range from about 0.25 to 1.0 WHSV. A preferred range is from about 0.5 to 0.75 WHSV.
[0040] Along with cyclic amines other oxygenated cyclic products with amino alcohols and dimines are also found in the products. The products have been identified in this work by one or more of the following analytical procedures; viz, gas-liquid chromatography (GC), infrared (IR), mass spectrometry (MS), or a combination of these techniques.
[0041] The examples which are discussed below were conducted in a vapour phase down flow reactor. The feedstocks were aqueous diol solution. The WHSV was varied from 0.25 to 1.0. The preferred amino cyclization took place over a range of temperatures from about 250° C. to about 400° C. The reaction of 1,5-pentane diol was carried out with varying the Si/Al ratio from 15 to 140. As the Si/Al ratio is increased a decrease in the formation of piperidine and increase in the pyron.
[0042] By contrast, poor hydroamination of a 25% aqueous solution of 1,3-propanediol to 1,3-propanediamine was realized in Examples 12 and 13, using copper-rich and copper-cobalt catalysts of the prior art.
[0043] To illustrate the process of the invention, the following examples are given. It is understood, however, that the examples are given only in the way of illustration and are not to be regarded as limiting the invention in any way.
EXAMPLES
[0044] A pyrex glass reactor of 20 mm dia with 60 mm length down flow reaction was used for the fixed bed experiments with the 30 mm bed length of 4 g of the modified or unmodified zeolite catalyst. The ammonia source was used as gas form. The diluted diol was passed through the preheating zone in the form of gas.
Example 1
[0045] Preparation of 5 wt % of Cu-ZSM-5: 0.95 g of Copper nitrtate was dissolved in 100 ml of distilled water and then 4 g of 18-30 mesh of calcined ZSM-5 was added then the catalyst was soaked for 6 hours. The distilled water was evaporated by heating and then the catayst was calcined for 4 hr at 420° C.
Example 2
[0046] The 1.7 ml of 1,5-pentandiol and water was fed onto the catalytic bed packed with Cu-ZSM-5 in the flow rate of 2 ml/h at 280° C. temperature. The yield of piperidine is 76.4 wt % at conversion of 99.9 wt %.
Example 3
[0047] Table 1 presents a series of Runs with various modified catalysts and their product distribution at the same conditions followed in Example 2.
TABLE 1 Aminocyclisation of 1,5 penatne diol: variation of catalyst Conver- sion of 1,5 pentane % Yield of products TOS diol Piper- 5-amino Catalyst (h) (%) Pyran dine pentanol Others Mn ZSM-5 (30) 4 99.9 18.5 67.3 5.9 8.2 Co ZSM-5 (30) 4 99.9 17.5 56.0 9.2 7.2 Ni ZSM-5 (30) 4 99.9 4.6 90.2 1.0 4.1 CU ZSM-5 (30) 3 + 4 99.9 19.0 62.2 — 18.7 Zn ZSM-5 (30) 4 99.9 14.7 46.7 14.0 24.5 Pb ZSM-5 (30) 3 99.9 12.7 81.8 — 5.4 Zr ZSM-5 (30) 2 97.6 29.0 29.0 18.5 21.1 Mo ZSM-5 (30) 4 91.6 30.6 19.4 35.0 6.6
[0048] Feed: 1,5 Pentane diol+Water: 1:3; temperature=300° C.; WHSV=0.5 h −1 ; Catalyst weight=4 g; metal weight=5 wt %; in others unsaturated alcohols and aldehydes are major
Example 4
[0049] The 1.7 ml of 1,5-pentandiol and water was fed onto the catalytice bed packed with Ni-ZSM-5 in the flow rate of 2 ml/h at 280° C. temperature, The yield of piperidine is 90.2 wt % at conversion of 99.9 wt %.
Example 5
[0050] The 1.7 ml of 1,5-pentandiol and water was fed onto the catalytice bed packed with Cu-ZSM-5 in the flow rate of 2 ml/h at 350° C. temperature. The yield of piperidine is 26.2 wt % at conversion of 51.4 wt %.
Example 6
[0051] The 1,4-butanediol and water in volume 1:3 ratio was fed onto the catalytic bed packed with Cu-ZSM-5 in the flow rate of 2 ml/h at 250° C. temperature. The yield of pyrrolidine is 99.0 wt % at conversion of 99.9 wt %.
Example 7
[0052] [0052] TABLE 2 represents the runs of various catalysts and their product distribution at the same conditions given in Example 6. Conversion of 1,4- TOS butanediol % Yield of products Catalyst (h) (%) THF Furan Pyrrole Pyrrolidine Others H ZSM-5 (30) 4 93.3 23.3 — — 16.0 54.0 Cr ZSM-5 (30) 3 86.1 52.7 20.3 — — 13.1 Fe ZSM-5 (30) 4 99.9 — — — 95.9 4.0 Mn ZSM-5 (30) 2 95.8 17.5 — 36.2 27.5 14.6 Cu ZSM-5 (30) 4 99.9 — — — 99.0 0.9 La ZSM-5 (30) 3 99.9 — — 93.8 3.0 3.1
[0053] Feed: 1,4 Butanediol+Water: 1:3; temperature=250° C.; WHSV=0.5 h −1 ; Catalyst weight=4 g; metal weight=5 wt %; in others unsaturated alcohols and aldehydes are major.
Example 8
[0054] 1,6-hexanediol and water in volume ratio of 1:3 was fed onto the catalytic bed packed with Cu-ZSM-5 in the flow rate of 2 ml/h at 300° C. temperature, the yield of hexamethylene imine is 68.4 wt % at conversion of 99.9 wt %.
Example 9
[0055] 1,6-hexanediol and water in volume ratio of 1:3 was fed onto the catalytic bed packed with M-ZSM-5 in the flow rate of 2 ml/h at 300° C. temperature and the product distribution is given in Table 3.
TABLE 3 Conversion of 1,6- % Yield of products(wt%) TOS hexanediol Hexamethyl- 6-amino-1 Catalyst (h) (%) ene imine Oxepane hexanol Others H ZSM-5 (30) 3 73.6 49.2 15.9 1.4 7.1 HZSM-5 (280) 3 62.8 34.3 12.8 10.7 5.0 Cr ZSM-5 (30) 3 99.9 20.3 58.3 5.9 15.4 Cu ZSM-5 (30) 3 99.9 30.9 41.4 4.1 23.5 Ni ZSM-5 (30) 3 + 4 98.6 18.6 28.4 19.6 32.0 Ce ZSM-5 (30) 3 99.9 88.3 — 4.5 7.1
[0056] Feed: 1,6 hexane diol+Water: 1:3; temperature=300° C. WHSV=0.5 h −1 ; Catalyst weight=4 g; metal weight=5 wt %; in others unsaturated alcohols and aldehydes are major.
[0057] Advantages of the Invention
[0058] The present invention provides a process that comprises of environmentally clean and economical technology, easily seperable and it can be recycled and reused.
[0059] This process provides an attractive route to the value added commodity chemicals
[0060] This method provides a selective heterogeneous catalyst with longer life.
[0061] This method provides a route, wherein a particular kind of product can be obtained selectively by substituting a particular metal ion.
[0062] References
[0063] Josef Pasek et al, “Equilibrium Conditions for Amination of Alcohols and Carbonyl Compounds,” Ind. Eng. Chem. Prod. Res. Develop., 11, 3, 333-337 (1972). Month unavailable.
[0064] Alfons Baiker et al., “Catalytic Amination of Long Chain Aliphatic Alcohols,” Ind. Eng. Chem., Prod. Res. Dev., 16, 3, 261-266 (1977). Month unavailable. Michael E. Ford et al., Selective Catalytic Synthesis of Mixed Alkylamines and Polyfunctional Amines, Catalysis of Organic Reactions, D. W. Blackburn, ed., Ch. 14, pp. 219-240 (1990) month unavailable.
[0065] J. F. Knifton and D. J. Janitor, “Diaminoalkane Syntheses Via Selective Amination of Hydroxy Aldehydes,” Patent Application Serial No. 60/109,572, filed Nov. 23, 1998 (Docket No. TH-1160). | Disclosed is a process for selectively producing aliphatic cyclic amines which comprises reacting a dihydric alcohol characterized by four to six carbons, preferably 1,5-pentane diol, with excess ammonia in presence of ZSM-5 catalyst modified with group of elements nickel, copper or cobalt-containing, at a temperature of at least 250° C., wherein said catalyst incorporates at least one metal. | 2 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of U.S. patent application Ser. No. 09/968,046, filed Oct. 1, 2001, which is fully incorporated herein by reference.
FIELD OF THE INVENTION
This invention relates generally to a spinal implant assembly for implantation into the intervertebral space between adjacent vertebral bones to simultaneously provide stabilization and continued flexibility and proper anatomical motion, and more specifically to such a device which utilizes a spirally slotted belleville washer, having radially extending grooves, as a restoring force generating element.
BACKGROUND OF THE INVENTION
The bones and connective tissue of an adult human spinal column consists of more than 20 discrete bones coupled sequentially to one another by a tri-joint complex which consists of an anterior disc and the two posterior facet joints, the anterior discs of adjacent bones being cushioned by cartilage spacers referred to as intervertebral discs. These more than 20 bones are anatomically categorized as being members of one of four classifications: cervical, thoracic, lumbar, or sacral. The cervical portion of the spine, which comprises the top of the spine, up to the base of the skull, includes the first 7 vertebrae. The intermediate 12 bones are the thoracic vertebrae, and connect to the lower spine comprising the 5 lumbar vertebrae. The base of the spine is the sacral bones (including the coccyx). The component bones of the cervical spine are generally smaller than those of the thoracic spine, which are in turn smaller than those of the lumbar region. The sacral region connects laterally to the pelvis. While the sacral region is an integral part of the spine, for the purposes of fusion surgeries and for this disclosure, the word spine shall refer only to the cervical, thoracic, and lumbar regions.
The spinal column of bones is highly complex in that it includes over twenty bones coupled to one another, housing and protecting critical elements of the nervous system having innumerable peripheral nerves and circulatory bodies in close proximity. In spite of these complications, the spine is a highly flexible structure, capable of a high degree of curvature and twist in nearly every direction.
Genetic or developmental irregularities, trauma, chronic stress, tumors, and degenerative wear are a few of the causes that can result in spinal pathologies for which surgical intervention may be necessary. A variety of systems have been disclosed in the art which achieve immobilization and/or fusion of adjacent bones by implanting artificial assemblies in or on the spinal column. The region of the back which needs to be immobilized, as well as the individual variations in anatomy, determine the appropriate surgical protocol and implantation assembly. With respect to the failure of the intervertebral disc, the interbody fusion cage has generated substantial interest because it can be implanted laparoscopically into the anterior of the spine, thus reducing operating room time, patient recovery time, and scarification.
Referring now to FIGS. 1 and 2, in which a side perspective view of an intervertebral body cage and an anterior perspective view of a post implantation spinal column are shown, respectively, a more complete description of these devices of the prior art is herein provided. These cages 10 generally comprise tubular metal body 12 having an external surface threading 14 . They are inserted transverse to the axis of the spine 16 , into preformed cylindrical holes at the junction of adjacent vertebral bodies (in FIG. 2 the pair of cages 10 are inserted between the fifth lumbar vertebra (L 5 ) and the top of the sacrum (S 1 ). Two cages 10 are generally inserted side by side with the external threading 14 tapping into the lower surface of the vertebral bone above (L 5 ), and the upper surface of the vertebral bone (S 1 ) below. The cages 10 include holes 18 through which the adjacent bones are to grow. Additional material, for example autogenous bone graft materials, may be inserted into the hollow interior 20 of the cage 10 to incite or accelerate the growth of the bone into the cage. End caps (not shown) are often utilized to hold the bone graft material within the cage 10 .
These cages of the prior art have enjoyed medical success in promoting fusion and grossly approximating proper disc height. It is, however, important to note that the fusion of the adjacent bones is an incomplete solution to the underlying pathology as it does not cure the ailment, but rather simply masks the pathology under a stabilizing bridge of bone. This bone fusion limits the overall flexibility of the spinal column and artificially constrains the normal motion of the patient. This constraint can cause collateral injury to the patient's spine as additional stresses of motion, normally borne by the now-fused joint, are transferred onto the nearby facet joints and intervertebral discs. It would therefore, be a considerable advance in the art to provide an implant assembly which does not promote fusion, but, rather, which nearly completely mimics the biomechanical action of the natural disc cartilage, thereby permitting continued normal motion and stress distribution.
It is, therefore, an object of the present invention to provide a new and novel intervertebral spacer which stabilizes the spine without promoting a bone fusion across the intervertebral space.
It is further an object of the present invention to provide an implant device which stabilizes the spine while still permitting normal motion.
It is further an object of the present invention to provide a device for implantation into the intervertebral space which does not promote the abnormal distribution of biomechanical stresses on the patient's spine.
Other objects of the present invention not explicitly stated will be set forth and will be more clearly understood in conjunction with the descriptions of the preferred embodiments disclosed hereafter.
SUMMARY OF THE INVENTION
The preceding objects of the invention are achieved by the present invention which is a flexible intervertebral spacer device comprising a pair of spaced apart base plates, arranged in a substantially parallel planar alignment (or slightly offset relative to one another in accordance with proper lordotic angulation) and coupled to one another by means of a spring mechanism. In particular, this spring mechanism provides a strong restoring force when a compressive load is applied to the plates, and may also permit rotation of the two plates relative to one another. While there are a wide variety of embodiments contemplated, a preferred embodiment includes a belleville washer utilized as the restoring force providing element, the belleville washer being spirally slotted and having radially extending grooves.
More particularly, as the assembly is to be positioned between the facing surfaces of adjacent vertebral bodies, the base plates should have substantially flat external surfaces which seat against the opposing bone surfaces. Inasmuch as these bone surfaces are often concave, it is anticipated that the opposing plates may be convex in accordance with the average topology of the spinal anatomy. In addition, the plates are to mate with the bone surfaces in such a way as to not rotate relative thereto. (The plates rotate relative to one another, but not with respect to the bone surfaces to which they are each in contact with.) In order to prevent rotation of a plate relative to the bone, the upper and lower plates can include a porous coating into which the bone of the vertebral body can grow. (Note that this limited fusion of the bone to the base plate does not extend across the intervertebral space.)
In some embodiments (not in the preferred embodiment), between the base plates, on the exterior of the device, there is included a circumferential wall which is resilient and which simply prevents vessels and tissues from entering within the interior of the device. This resilient wall may comprise a porous fabric or a semi-impermeable elastomeric material. Suitable tissue compatible materials meeting the simple mechanical requirements of flexibility and durability are prevalent in a number of medical fields including cardiovascular medicine, wherein such materials are utilized for venous and arterial wall repair, or for use with artificial valve replacements. Alternatively, suitable plastic materials are utilized in the surgical repair of gross damage to muscles and organs. Still further materials that could be utilized herein may be found in the field of orthopedic in conjunction with ligament and tendon repair. It is anticipated that future developments in this area will produce materials that are compatible for use with this invention, the breadth of which shall not be limited by the choice of such a material.
As introduced above, the internal structure of the present invention comprises a spring member, which provides a restoring force when compressed. More particularly, it is desirable that the restoring forces be directed outward against the opposing plates, when a compressive load is applied to the plates. In addition, in certain embodiments, it is necessary that the restoring force providing subassembly not substantially interfere with the rotation of the opposing plates relative to one another. In the preferred embodiment, the spring subassembly is configured to allow rotation of the plates relative to one another. In other embodiments, the spring subassembly can be configured to either allow rotation of the plates, or prevent rotation of the plates (through the tightening of a set screw as discussed below). As further mentioned above, the force restoring member comprises at least one belleville washer.
Belleville washers are washers which are generally bowed in the radial direction. Specifically, they have a radial convexity (i.e., the height of the washer is not linearly related to the radial distance, but may, for example, be parabolic in shape). The restoring force of a belleville washer is proportional to the elastic properties of the material. In addition, the magnitude of the compressive load support and the restoring force provided by the belleville washer may be modified by providing slots and/or grooves in the washer. In the present invention, the belleville washer utilized as the force restoring member is spirally slotted, with the slots initiating on the periphery of the washer and extending along arcs which are generally radially inwardly directed a distance toward the center of the bowed disc, and has radially extending grooves that decrease in width and depth from the outside edge of the washer toward the center of the washer.
As a compressive load is applied to a belleville washer, the forces are directed into a hoop stress which tends to radially expand the washer. This hoop stress is counterbalanced by the material strength of the washer, and the strain of the material causes a deflection in the height of the washer. Stated equivalently, a belleville washer responds to a compressive load by deflecting compressively, but provides a restoring force which is proportional to the elastic modulus of the material in a hoop stressed condition. With slots and/or grooves formed in the washer, it expands and restores itself far more elastically than a solid washer.
In general, the belleville washer is one of the strongest configurations for a spring, and is highly suitable for use as a restoring force providing subassembly for use in an intervertebral spacer element which must endure considerable cyclical loading in an active human adult.
In the preferred embodiment of the present invention, a single modified belleville washer, which is of the slotted variety and has radially extending grooves as described above, is utilized in conjunction with a ball-shaped post on which it is free to rotate through a range of angles (thus permitting the plates to rotate relative to one another through a corresponding range of angles). More particularly, this embodiment comprises a pair of spaced apart base plates, one of which is simply a disc shaped member (preferably shaped to match the end of an intervertebral disc) having an external face (having the porous coating discussed above) and an internal face having an annual retaining wall (the purpose of which will be discussed below). The other of the plates is similarly shaped, having an exterior face with a porous coating, but further includes on its internal face a central post portion which rises out of the internal face at a nearly perpendicular angle. The top of this post portion includes a ball-shaped knob. The knob includes a central threaded axial bore which receives a small set screw. Prior to the insertion of the set screw, the ball-shaped head of the post can deflect radially inward (so that the ball-shaped knob contracts). The insertion of the set screw eliminates the capacity for this deflection.
As introduced above, a modified and spirally slotted belleville washer having radially extending grooves is mounted to this ball-shaped knob in such a way that it may rotate freely through a range of angles equivalent to the fraction of normal human spine rotation (to mimic normal disc rotation). The belleville washer of this design is modified by including an enlarged inner circumferential portion (at the center of the washer) which accommodates the ball-shaped portion of the post. More particularly, the enlarged portion of the modified belleville washer includes a curvate volume having a substantially constant radius of curvature which is also substantially equivalent to the radius of the ball-shaped head of the post. The deflectability of the ball-shaped head of the post, prior to the insertion of the set screw, permits the head to be inserted into the interior volume at the center of the belleville washer. Subsequent introduction of the set screw into the axial bore of the post prevents the ball-shaped head from deflecting. Thereby, the washer can be secured to the ball-shaped head so that it can rotate thereon through a range of proper lordotic angles (in some embodiments, a tightening of the set screw locks the washer on the ball-shaped head at one of the lordotic angles).
This assembly provides ample spring-like performance with respect to axial compressive loads, as well as long cycle life to mimic the axial biomechanical performance of the normal human intervertebral disc. The spiral slots and radially extending grooves of the belleville washer allow the washer to expand radially as the slots and grooves widen under the load, only to spring back into its undeflected shape upon the unloading of the spring. As the washer compresses and decompresses, the annual retaining wall maintains the wide end of the washer within a prescribed boundary on the internal face of the base plate which it contacts, and an annular retaining ring maintains the wide end of the washer against the internal face.
Finally, inasmuch as the human body has a tendency to produce fibrous tissues in perceived voids, such as may be found within the interior of the present invention, and such fibrous tissues may interfere with the stable and/or predicted functioning of the device, some embodiments of the present invention (although not the preferred embodiment) will be filled with a highly resilient elastomeric material. The material itself should be highly biologically inert, and should not substantially interfere with the restoring forces provided by the spring-like mechanisms therein. Suitable materials may include hydrophilic monomers such as are used in contact lenses. Alternative materials include silicone jellies and collagens such as have been used in cosmetic applications. As with the exterior circumferential wall, which was described above as having a variety of suitable alternative materials, it is anticipated that future research will produce alternatives to the materials described herein, and that the future existence of such materials which may be used in conjunction with the present invention shall not limit the breadth thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side perspective view of an interbody fusion device of the prior art.
FIG. 2 is a front view of the anterior portion of the lumbo-sacral region of a human spine, into which a pair of interbody fusion devices of the type shown in FIG. 1 have been implanted.
FIGS. 3 a and 3 b are side cross-section views of the upper and lower opposing plates of the preferred embodiment of the present invention.
FIGS. 4 a and 4 b are top and side cross-section view of a belleville washer having radially extending grooves and spiral slots, for use in a preferred embodiment of the present invention.
FIG. 5 a is a top view of the upper plate of FIG. 3 a , with the belleville washer of FIGS. 4 a and 4 b fitted within a retaining wall and a retaining ring of the upper plate.
FIG. 5 b is a top view of the lower plate of FIG. 3 b.
FIG. 6 is a side cross-section view of the preferred embodiment of the present invention, which utilizes a belleville washer of the type shown in FIGS. 4 a and 4 b , showing the plates of FIGS. 5 a and 5 b assembled together.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
While the present invention will be described more fully hereinafter with reference to the accompanying drawings, in which particular embodiments and methods of implantation are shown, it is to be understood at the outset that persons skilled in the art may modify the invention herein described while achieving the functions and results of this invention. Accordingly, the descriptions which follow are to be understood as illustrative and exemplary of specific structures, aspects and features within the broad scope of the present invention and not as limiting of such broad scope. Like numbers refer to similar features of like elements throughout.
Referring now to FIGS. 3 a and 3 b , side cross-section views of upper and lower plate members 100 , 200 of the preferred embodiment of the present invention are shown. As the device is designed to be positioned between the facing surfaces of adjacent vertebral bodies, the plates include substantially flat external face portions 102 , 202 which seat against the opposing bone surfaces. In addition, the plates are to mate with the bone surfaces in such a way as to not rotate relative thereto. It is, therefore, preferred that the external faces of the plates include a porous coating 104 , 204 into which the bone of the vertebral body can grow. (Note that this limited fusion of the bone to the base plate does not extend across the intervertebral space.) A hole (not shown) can be provided in the upper plate such that the interior of the device may be readily accessed if a need should arise.
The upper plate 100 includes an internal face 103 that includes an annular retaining wall 108 and an annular retaining ring 109 . The lower plate 200 includes an internal face 203 that includes a central post member 201 which rises out of the internal face 203 at a nearly perpendicular angle. The top of this post member 201 includes a ball-shaped head 207 . The head 207 includes a series of slots which render it compressible and expandable in correspondence with a radial pressure (or a radial component of a pressure applied thereto). The head 207 includes a central threaded axial bore 209 which extends down the post 201 . This threaded bore 209 is designed to receive a set screw 205 . Prior to the insertion of the set screw 205 , the ball-shaped head 207 of the post 201 can deflect radially inward because of the slots (so that the ball-shaped head contracts). The insertion of the set screw 205 eliminates the capacity for this deflection.
Referring now to FIGS. 4 a and 4 b , a spirally slotted belleville washer 130 having radially extending grooves is provided in top and side cross-section views. The belleville washer 130 is a restoring force providing device which comprises a circular shape, having a central opening 132 , and which is radially arched in shape. The belleville washer 130 has a radial convexity 134 (i.e., the height of the washer 130 is not linearly related to the radial distance, but may, for example, be parabolic in shape). The restoring force of the belleville washer 130 is proportional to the elastic properties of the material.
The belleville washer 130 comprises a series of spiral slots 131 formed therein. The slots 131 extend from the outer edge of the belleville washer, inward along arcs generally directed toward the center of the element. The slots 131 do not extend fully to the center of the element. In preferred embodiments, the slots may extend anywhere from a quarter to three quarters of the overall radius of the washer, depending upon the requirements of the patient, and the anatomical requirements of the device.
The belleville washer 130 further comprises a series of grooves 133 formed therein. The grooves 133 extend radially from the outer edge of the belleville washer toward the center of the element. In the preferred embodiment, the width 135 and depth 137 of each groove 133 decreases along the length of the groove 133 from the outer edge of the washer toward the center of the washer, such that the center of the washer is flat, while the outer edge of the washer has grooves of a maximum groove depth. It should be understood that in other embodiments, one or both of the depth and the width of each groove can be (1) increasing along the length of the groove from the outer edge of the washer toward the center of the washer, (2) uniform along the length of the groove from the outer edge of the washer toward the center of the washer, or (3) varied along the length of each groove from the outer edge of the washer toward the center of the washer, either randomly or according to a pattern. Moreover, in other embodiments, it can be the case that each groove is not formed similarly to one or more other grooves, but rather one or more grooves are formed in any of the above-mentioned fashions, while one or more other grooves are formed in another of the above-mentioned fashions or other fashions. It should be clear that any groove pattern can be implemented without departing from the scope of the present invention.
As a compressive load is applied to the belleville washer 130 , the forces are directed into a hoop stress which tends to radially expand the washer. This hoop stress is counterbalanced by the material strength of the washer, and the force necessary to widen the spiral slots 131 and the radial grooves 133 along with the strain of the material causes a deflection in the height of the washer. Stated equivalently, the belleville washer 130 responds to a compressive load by deflecting compressively; the spiral slots and/or radial grooves cause the washer to further respond to the load by spreading as the slots and/or the grooves in the washer expand under the load. The spring, therefore, provides a restoring force which is proportional to the elastic modulus of the material in a hoop stressed condition.
More particularly, the central opening 132 of the belleville washer is enlarged. This central opening 132 includes a curvate volume 233 for receiving therein the ball-shaped head 207 of the post 201 of the lower plate 200 described above. More particularly, the curvate volume 233 has a substantially constant radius of curvature which is also substantially equivalent to the radius of the ball-shaped head 207 of the post 201 . In this embodiment, the spiral slots 131 do not extend all the way to the central opening 132 , and approach the opening only as far as the material strength of the washer can handle without plastically deforming under the expected anatomical loading. Further in this embodiment, the depth 137 of each groove 133 decreases along the length of the groove 133 from the outer edge of the washer toward the center of the washer, such that the center of the washer is flat, while the outer edge of the washer has grooves of a maximum groove depth. Therefore, the central opening 132 can be formed from flat edges. It should be understood that this is not required, but rather is preferred for this embodiment.
Referring now to FIG. 5 a , a top view of the upper plate 100 of FIG. 3 a , with the spirally slotted and radially grooved belleville washer 130 of FIGS. 4 a and 4 b fitted within a retaining wall 108 and a retaining ring 109 of the upper plate 100 , is shown. The diameter of the retaining wall 108 is preferably slightly wider than the diameter of the undeflected belleville washer 130 such that the loading thereof can result in an unrestrained radial deflection of the washer 130 . FIG. 5 b shows a top view of the lower plate 200 of FIG. 3 b.
Referring also to FIG. 6, which shows the fully assembled preferred embodiment of the present invention is shown. The spirally slotted and radially grooved belleville washer 130 is placed with its wide end against the top plate 100 within the annular retaining wall 108 as shown in FIG. 5 b . The annular retaining ring 109 is provided to hold the belleville washer 130 against the internal face 103 of the upper plate 100 within the retaining wall 108 . The post 201 of the lower plate 200 is fitted into the central opening 132 of the belleville washer 130 (the deflectability of the ball-shaped head 207 of the post 201 , prior to the insertion of the set screw 205 , permits the head 207 to be inserted into the interior volume 233 at the center of the belleville washer 130 . Subsequent introduction of the set screw 205 into the axial bore 209 of the post 201 eliminates the deflectability of the head 207 so that the washer 130 cannot be readily removed therefrom, but can still rotate thereon. In some embodiments (not in this preferred embodiment), the post head 207 can be locked tightly within the central volume 233 of the belleville washer 130 by the tightening of the set screw 205 , to prevent any rotation of the plates 100 , 200 . Compressive loading of the assembly causes the washer 130 to deflect (with the spiral slots and the radially extending grooves enhancing the deflection) so that the wide end radially expands while being maintained centrally against the upper plate 100 by the retaining wall 108 and the retaining ring 109 . When the load is removed, the washer 130 springs back to its original shape.
Inasmuch as the human body has a tendency to produce fibrous tissues in perceived voids, such as may be found within the interior of the present invention, and such fibrous tissues may interfere with the stable and/or predicted functioning of the device, some embodiments of the present invention (although not the preferred embodiment) will be filled with a highly resilient and biologically inert elastomeric material. Suitable materials may include hydrophilic monomers such as are used in contact lenses. Alternative materials include silicone jellies and collagens such as have been used in cosmetic applications.
While there has been described and illustrated specific embodiments of an intervertebral spacer device, it will be apparent to those skilled in the art that variations and modifications are possible without deviating from the broad spirit and principle of the present invention. The invention, therefore, shall not be limited to the specific embodiments discussed herein. | An intervertebral spacer device having a pair of opposing plates for seating against opposing vertebral bone surfaces, separated by at least one spring mechanism. The preferred spring mechanism is at least one spirally slotted belleville washer having radially extending grooves. In a preferred embodiment there is a single such belleville washer which is modified to mount onto a ball-shaped head. The lower plate of this embodiment includes a post extending upwardly from the inner surface of the plate, the post including a ball-shaped head. The modified belleville washer can be rotatably mounted to the head such that the wider portion of the washer seats against the upper plate. | 0 |
BACKGROUND
The present invention relates to baby cribs and more particularly to a novel three-in-one crib arrangement capable of functioning as a bassinet, changing table and bedside sleeper.
SUMMARY
It is not uncommon for families having an infant to provide a separate bassinet, changing table and bedside sleeper. Obviously all of these units occupy space and can make an infant's room quite confining, especially in instances where the infant's room is small. Also, the costs of these units can be prohibitive to many potential customers
The present invention is characterized by comprising an apparatus in which all the capabilities of bassinet, changing table and bedside sleeper are integrated into one unitary apparatus which is capable of being changed over quite simply and quite readily.
The apparatus of the present invention comprises a light-weight and yet sturdy and stable skeletal structure which is designed to function as a rocking bassinet when the casters provided thereon are drawn in from the rolling position. The housings for the casters extend well beyond the curved rocking members to limit the degree of rocking and thereby provide added stability for the structure. The casters, when lowered, allow the structure to be easily rolled and are also capable of being locked in the “down” position when it is desired to prevent the structure from rolling.
Swingably mounted hoops (i.e. gussets) are provided for adjustably supporting a hood to cover the baby's eyes from light, which swingable hoops are capable of being lowered to gain total access to the surface supporting the infant.
A section of the top support of the skeletal structure is removable to gain access to the interior of the bedside sleeper when positioned adjacent to parent's bed or when used as a changing table. Nevertheless, a safety bar is provided to act as a barrier to prevent the child from easily rolling out of the bedside sleeper. The sleeper is secured to the parents' bed by safety straps which are placed beneath the mattress and preferably between the mattress and the bedspread to assure safe, secure attachment of the bedside sleeper to the parents' bed.
The skeletal structure is covered with a lightweight, durable, washable fabric which is designed to provide an aesthetic exterior appearance. The cover includes a side storage bag and larger underside storage area to provide adequate room for diapers, baby clothes and other items such as powders, salves, ointments, creams and the like typically advantageously provided in close proximity to a changing table.
The skeletal supporting structure is adjustable preferably to at least four different heights to align the structure to the parents' bed when used as bedside sleeper and also when used as either a changing table or bassinet, to accommodate the height of the person attending to the infant.
The entire structure is extremely light in weight and easy to use and yet quite rugged and stable and is easily and quickly assembled and disassembled for compact storage, transportation and use.
It is therefore one object of the present invention to provide a novel apparatus capable of functioning as a bassinet, changing table and bedside sleeper requiring very minor adjustment to convert to any one of the above functions.
Still another object of the present invention is to provide a novel apparatus capable of functioning as a bassinet, changing table and bedside sleeper and which is comprised of a skeletal superstructure which is lightweight and yet strong, rugged and stable and which is covered by a lightweight, sturdy, washable, aesthetically pleasing fabric which, in addition to accommodating the baby, is provided with accessible storage areas respectively located to one side and the underside of the apparatus.
The above as well as other objects of the present invention will become apparent when reading the accompanying description and drawings in which:
BRIEF DESCRIPTION OF THE DRAWING(S)
FIGS. 1 a and 1 b are perspective views respectively showing the skeletal structure of the present invention with the casters in the supporting and concealed position.
FIGS. 1 c and 1 d respectively show side and end views of the structure of FIG. 1 a.
FIG. 1 e draws a more detailed view of one of the wheel assemblies of FIGS. 1 a and 1 b.
FIG. 1 f is a detailed view of one of the brackets of FIG. 1 a.
FIG. 1 g is an exploded, detailed view of the removable rod of FIG. 1 a and the cooperating brackets
FIG. 2 is a perspective view showing the skeletal structure of FIG. 1 covered to form the 3-in-1 structure of the present invention.
FIG. 3 shows a sectional view of the cover structure for covering the skeletal structure of FIG. 1 a.
FIG. 3 a is a perspective view of a portion of the cover structure showing the manner in which the cover structure converts from a bassinet to a co-sleeper.
FIG. 3 b is an elevational view showing the manner in which the co-sleeper is held against a parent's bed.
FIG. 4 is a perspective view of the storage basket shown in FIGS. 1 c and 1 d.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1 a-d and 3 d show the skeletal structure 10 embodying the principles of the present invention and comprising a pair of inverted, substantially U-shaped, hollow, tubular members 12 and 14 respectively having depending legs 12 a - 12 b , 14 a - 14 b extending downwardly, and a yoke portion 12 c , 14 c.
A pair of hollow curved tubular members 16 , 18 are each joined to retractable wheel assemblies 20 - 22 and 24 - 26 respectively mounted at opposite ends thereof.
The retractable wheel assemblies, as shown in FIG. 1 d are each provided with a recess for receiving an end 16 b , 16 c of a curved member 16 . The tubular member 18 is secured to the wheel assemblies 24 , 26 in like fashion to that shown in FIG. 1 d.
FIG. 1 e is a detailed view of one wheel assembly 24 showing the recess 24 b for receiving an end of tubular member 18 . The retractable wheels shown in FIG. 1 a , are in the “down” position where the skeletal structure is capable of being easily rolled along a surface. The wheels are moved upwardly to a retracted position by operating a toggle button 24 c and an operating lever 24 d surrounding toggle switch 24 c . Toggle button 24 c pivots about a vertical axis A and is normally urged into a locked position. Pushing button 24 c at the right-hand end unlocks the castor assembly 24 a , allowing lever 24 d to be rotated in order to rotate caster 24 a clockwise about the disc-shaped portion 24 i at the upper end of the arm 24 j holding caster 24 a , disc-shaped portion being swingably mounted within an opening 24 b in housing 24 l . Lowering the caster 24 a is performed by operating the toggle button in a similar manner, however, the lever 24 d is rotated counter-clockwise to lower the caster 24 a . When pressure on the right-hand end of toggle button 24 c is released, the toggle button returns to the locked condition. Moving the casters 20 a , 22 a 24 a , 26 a into their recesses enables the skeletal structure to be rocked by the curved convex central portions 16 a , 18 a of tubular members 16 , 18 . Even though the wheels 20 a , 22 a , 24 a and 26 a are retracted, the underside of their housings such as 16 b , 16 c , can engage the surface supporting the skeletal structure, preventing the structure, when it is rocked, from toppling over (see FIG. 1 d ). The wheel assemblies are provided with conventional locking members, such as the slide switch 24 f (not shown in detail for purposes of simplicity), which, when moved in one direction, lock the wheels 22 a - 26 a from rolling when they are in the “down” position. Sliding the switch 24 f in the opposite direction unlocks the wheels allowing them to roll freely. The outwardly projecting housings for the wheels provide a wider “footprint” to greatly enhance the stability of the skeletal structure.
Wheel assemblies 20 - 26 are further provided with integral, upwardly directed, hollow tubular projections 20 g - 26 g (see FIG. 1 e ) each adapted to receive the lower end of one of the elongated, hollow, tubular, upright members 28 - 30 and 32 - 34 , which extend into the hollow projections 20 g - 26 g of assemblies 20 - 26 . The upper ends of tubular members 28 - 34 each telescope into a lower end of one of the legs 12 b - 14 b , 12 a - 14 a . The legs 12 b - 14 b , 12 a - 14 a are provided with an array of spaced openings, such as, for example, the openings O shown provided on legs 14 a , 14 b , for purposes of receiving a conventional spring loaded button B provided on an upper end of each tubular member which locks into one of the openings provided on each leg, enabling the tubular members 12 and 14 to be raised (or lowered) to a desired height. The legs of each tubular member 28 - 34 can be adjusted simply by pressing the buttons B inwardly so that they are cleared of the openings O and moving the members 12 and 14 relative to the members 28 - 30 and 32 - 34 . As soon as the spring loaded button B aligns with an opening, the spring loaded button B will snap into the opening and lock the associated leg at a desired height. All of the buttons B for each of the remaining three legs operate in a similar manner.
Integral hollow projections 29 - 33 provided on assemblies 22 , 20 receive a rod 37 which provides additional structural support. A similar rod 39 extends between similar integral, hollow projections 31 - 35 to provide similar structural support. Rods 39 and 37 are snap-filled into the projections and extend through sleeves B 3 , B 4 in storage basket 70 , shown in FIGS. 1 c , 1 d and 4 . The basket 70 is formed of a light-weight, open weave, mesh fabric which enables the contents of the basket to be easily observed through the side panels 76 , 78 and end panels 80 , 82 The vertically aligned corners C 1 -C 4 are each comprised of strips formed of a suitable, rugged, tight-weave, durable fabric to support the basket. Bottom end strips B 1 and B 2 are similar to strips C 1 -C 4 . Likewise top side strips T 1 , T 2 and top end strips T 3 , T 4 each serve to rigidify the basket to assist in retaining its rectangular, box-like shape. The elongated strips T 1 -T 4 , C 1 -C 4 and B 1 -B 4 are preferably formed of more rugged, tightly-woven, rugged, strips of material which are sewn to the mesh material to form a basket.
The basket 70 makes excellent use of the open region beneath board 56 supported by tubular members 36 , 38 . The basket 70 is suspended from the skeletal structure by means of four (4) elongated straps S 1 -S 4 arranged in each of the four corners of the basket 70 . The straps are each provided with a plurality of spaced, female snap members 84 . One of the snaps 84 is snap-fitted with a cooperating male snap member 86 each male snap member being provided at opposite ends of yokes 12 c , 14 c (see FIG. 1 c ). The female snap member 84 which is snap-fitted to member 86 is chosen so as to keep the basket 70 upright and suitably taut.
Pairs of tie members 80 , 90 , 92 and 94 are provided at the upper corners of basket 70 and are tied about the upper portions of legs 12 a - 12 b , 14 a - 14 b to hold the basket taut in the horizontal direction.
The pair of upright, substantially U-shaped tubular members 36 , 38 have yoke portions 36 a , 38 a resting upon the yoke portions 12 c , 14 c and preferably joined thereto, for example, by suitable fasteners, which also secure the board 56 thereto. Standoffs 56 a maintain board 56 parallel to yokes 12 c and 14 c , see FIGS. 1 c and 1 d . Members 36 and 38 are arranged substantially at right angles to yokes 12 c and 14 c . Member 36 has upwardly directed arms 36 b , 36 c and member 38 has upwardly directed arms 38 b , 38 c . Brackets 40 and 42 join the free ends of 44 a , 44 b of the curved tubular member 44 and first ends 46 a , 48 a of straight tubular members 46 and 48 to the upright arms 36 a and 36 b . Similar brackets 50 , 52 join the opposite ends 46 b , 48 b of tubular members 46 and 48 and the free ends 54 a , 54 b of curved tubular member 54 to the upright arms 38 b , 38 c . The tubular members 44 and 36 b are pivotally mounted to bracket 42 to allow these members to fold into a compact arrangement when disassembled and stored. The brackets 40 , 50 and 52 are similar in design and function.
Rigid board 56 is secured to the yoke portions 36 a , 38 a of tubular members 36 and 38 by the aforementioned suitable fasteners (not shown) and serves as the base of the bassinet/changing table/bedside sleeper and as a support for a mattress 120 (FIG. 3 ).
Brackets 58 and 60 are releasably, mounted to locking projections arranged on the underside of rods 46 , 48 , For example, FIG. 1 f shows rod 48 , having cooperating projection 48 c secured to rod 48 by pin 49 . Bracket 60 has a cooperating slot 60 a which is slidably mounted upon projection 48 c . The free ends of curved gusset members 62 , 64 and 66 are pivotally mounted upon the brackets 58 , 60 by pin 67 . Gusset members 62 , 64 and 66 serve as the means for supporting a hood H (see FIG. 2) to shield the infants' eyes from overhead light, as will be more fully described. The brackets 58 , 60 which slidably mount to the rods 46 , 48 as set forth above, may be removed by sliding the brackets 60 away from the projections, such as projection 48 c , enabling the canopy H to be easily removed/replaced. The gussets 62 - 66 are swingably mounted to brackets 58 - 60 to enable hood H to be easily raised and lowered.
The tubular members 35 , 44 , 46 & 48 are preferably enclosed in elongated, resilient, foam-type, plastic sleeves, such as sleeve S, shown in FIG. 1 f , to cushion these rods and reduce injury to an infant or other person engaging these rods.
FIG. 2 shows the skeletal structure 10 covered with a fabric member 100 . Making reference to FIG. 3 as well as FIG. 2, the fabric member 100 is comprised of interior sidewalls, FIG. 2 showing two (2) straight sidewalls 102 , 106 and two (2) curved sidewalls 104 , 108 . The straight sidewalls 102 , 106 , shown in the sectional view of FIG. 3, as well as curved sidewall 104 , have their lower ends joined, preferably by being sewn, to a bottom sheet 110 . The sewn portions joining sidewalls 102 and 106 to the bottom sheet are shown at 112 and 114 . The two curved sidewalls 104 and 108 are joined in a like manner, being sewn to the outer perimeter of bottom sheet 110 .
Bottom sheet 110 rests upon the upper surface of board 56 . A mattress 120 (shown in dotted fashion), is placed upon bottom sheet 110 .
The upper ends of straight sidewalls 102 and 106 respectively rest on rods 46 and 48 and a portion of their free ends are each sewn to an integral skirt portions 118 , 116 which skirt portions hang downwardly preferably to a point below the board 56 . The short sidewalls are likewise joined to skirt portions 117 , 119 in a like manner, as by sewing.
The surfaces 102 a and 106 a of the sidewalls 102 and 106 are provided with male-type snap buttons 103 a , 103 b . The surfaces 118 a , 116 a are each provided with male-type snap buttons 105 a , 105 b . The buttons 105 a , 105 b are arranged to be snap-fitted with buttons 103 a , 103 b . It should be understood that a plurality of pairs of cooperating snap-buttons 103 a , 103 b and 105 a , 105 b are arranged at spaced intervals along the straight sidewalls 102 , 106 (as well as curved sidewalls 104 and 108 ), all of which pairs are snap-fitted together to retain the cover member in place draped over the skeletal frame. If desired, cooperating loop-type and hook-type strips may be substituted for the buttons without any change in effectiveness.
The placement of the mattress 120 upon the bottom sheet 110 cooperates with the button pairs to retain the cover member 100 in place.
The sidewall 106 of cover member 110 is capable of being pulled away from the adjacent curved sidewalls 104 , 108 . As shown in FIG. 3 a , which shows lower portions of the skirt removed to assist in an understanding of FIG. 3 a , ends of the straight sidewall 106 are each provided with elongated hook-type strips 107 a , 107 b which are aligned to be joined with elongated loop-type strips 109 a , 109 b , shown in dotted fashion, along adjacent ends of the curved sidewalls 104 , 108 .
In order to convert the bassinet to a beside co-sleeper, the gussets 62 - 66 are removed by removing the brackets 58 and 60 , brackets 58 and 60 being slidably joined to projections on the rods 46 and 48 . The fabric member 100 is provided with elongated slits aligned with the projections on rods 46 and 48 for receiving the brackets 58 , 60 and to enable the brackets 58 and 60 to be easily assembled or disassembled from the aforesaid cooperating projections.
End 48 a of rod 48 has a reduced diameter and is removably insertable into opening 42 a in bracket 42 , as shown in FIG. 1 g . Opposite end 48 b also has a reduced diameter and is longer than end 48 a . End 48 b is snap-fittingly received in the substantially U-shaped projection 52 a at the end of bracket 52 . In order to remove rod 48 , after removal of bracket 60 and lifting of the skirt portion 108 (see FIG. 3 a ), end 48 b is lifted upward in the direction of arrow B and out of the projection 52 a . When end 48 b is released from the reduced diameter portion 52 b of projection 52 a , rod 48 is moved in the direction of arrow A to remove end 48 a from opening 42 a.
Rod 48 is replaced by inserting end 48 a into opening 42 a and then lowering end 48 b into projection 52 a until end 48 b moves below the reduced diameter portion 52 b , causing end 48 b to be snap-fitted into the projection 52 a.
Rod 48 is removed by lifting end 48 b upwardly and out of a locking recess in bracket 52 , similar to the locking recess 24 h on wheel assembly 24 (see FIG. 1 e ), and sliding rod 48 to the right out of the interior of bracket 42 until its left-hand end clears a receiving opening bracket 52 , at which time the rod 48 may be removed. As a safety feature, rod 35 has both of its ends secured to arms 36 b , 38 a . The distance between rod 35 and board 56 is sufficiently small to prevent an infant's head from becoming wedged between rod 35 and board 56 , while providing a barrier to prevent an infant from rolling out of the bassinet, even though rod 48 is removed.
Prior to removal of rod 48 , the skirt portion 116 joined to straight sidewall 106 is lifted to gain access to rod 48 .
After the brackets 58 , 60 and rod 48 are removed, the ends of straight sidewall 106 are pulled away from adjacent curved sidewalls 104 , 108 causing the cooperating button pairs to be moved apart to allow the straight sidewall 106 to be lowered and draped over rod 35 , providing easier access to the interior of the sleeper while still providing a barrier (rod 35 ) to prevent an infant from rolling out of the beside co-sleeper. The thick, quilted sidewall 106 , together with the resilient sleeves (see sleeve S in FIG. 1 f ), acts as a cushion to protect the infant from injury.
When the skirt portion 106 is pulled over the lower rod 35 , the upper flounce portion 106 a of skirt portion 106 is preferably aligned with the lower flounce position of the adjacent skirt portions, to enhance the aesthetic appearance even when the rod 48 is removed.
FIG. 3 b shows the manner in which the co-sleeper may be retained against one side of an adult bed B. An elongated pair of straps 130 , 131 each have loops 130 a , 131 a , provided at their free ends. The legs 12 a - 12 b are preferably respectively passed through loops 130 a , 131 a when the skeletal structure is initially assembled. The straps 130 , 131 are joined to a strap, 133 , which is preferably passed between the mattress 134 and box spring 135 (or between the mattress 135 and bed frame 137 ). A flat, rectangular-shaped anchoring member 136 having slot through which the strap 133 is threaded 134 , when aligned vertically, bridges across the region between and presses against the mattress and box spring 135 and rests against portions of the mattress and box spring. An adjustable, slidable locking member 136 a allows the strap 133 to be tightened, holding the beside sleeper in place against the left-handed side of the bed and holds the anchoring member in place against the right-hand side of the bed. It should be understood that the casters should be in the down position with the casters locked to prevent rolling.
The loops 130 a , 131 a of straps 130 , 131 shown in FIG. 3 b maybe released from the strap by conventional clip assemblies 138 , 140 , to allow the unit to be moved away from the adult bed without disturbing the straps 130 , 131 and 133 and the anchoring member 136 .
The sidewall 106 may be placed either over rod 35 or rod 48 when employed as a changing table. The height of the changing table may be raised or lowered to assure a comfortable height for use as a changing table.
The gussets 62 - 66 are covered with hood H, which is formed of an aesthetically pleasing fabric, to shade the infant's eyes from bright light and having elongated passageways (not shown) for receiving and concealing the gussets.
The convertible apparatus may be easily and quickly assembled and disassembled. When disassembled, the apparatus fits into a compact space and is easily transported due to the light-weight and yet rugged materials which are preferably either aluminum or rugged plastic or a combination thereof. | A combination bassinet, bedside sleeper and changing table apparatus including a supporting frame having a rocking feature convertible through adjustable locking casters for easy rolling. A fabric member comprised of sidewalls and a skirt is draped over the frame. The apparatus may be placed against one side of an adult bed for easy access by a parent. The bedside sleeper is secured to the parents' bed with safety straps. One sidewall may be lowered to facilitate access to an infant by removal of a removably mounted sidewall/skirt supporting rod. The apparatus is adjustable in height to align the bedside sleeper with the parents' bed and when used as a changing table to accommodate for differences in the height of the parent. The bassinet is provided with a removable, adjustable hood for shielding light from the baby's eyes. The apparatus comprises a skeletal structure covered with a soft, aesthetically pleasuring and yet sturdy cloth which is easily removable and washable and includes two convenient storage areas. | 0 |
PRIORITY CLAIM
This application is a continuation of, and claims priority to and the benefit of, U.S. patent application Ser. No. 13/901,295, filed on May 23, 2013, which is a continuation of, and claims priority to and the benefit of, U.S. patent application Ser. No. 13/743,069, filed on Jan. 16, 2013, which issued as U.S. Pat. No. 8,596,576 on Dec. 3, 2013, which is a continuation of, and claims priority to and the benefit of, U.S. patent application Ser. No. 12/702,935, filed on Feb. 9, 2010, which issued as U.S. Pat. No. 8,453,966 on Jun. 4, 2013, which claims priority to and the benefit of U.S. Provisional Patent Application No. 61/152,076, filed on Feb. 12, 2009, now expired, the entire contents of each of which are incorporated herein by reference.
CROSS REFERENCE TO RELATED APPLICATIONS
The present application relates to the following commonly-owned co-pending patent applications: U.S. patent application Ser. No. 13/527,177, filed on Jun. 19, 2012, U.S. patent application Ser. No. 13/899,172, filed on May 21, 2013, U.S. patent application Ser. No. 13/901,283, filed on May 23, 2013, U.S. patent application Ser. No. 13/900,191, filed on May 22, 2013, and U.S. patent application Ser. No. 14/034,097, filed on Sep. 23, 2013.
BACKGROUND
1. Field of Invention
The present invention addresses launch, retrieval, and servicing of a hovering aircraft, especially in turbulent winds or onto an irregularly-moving surface, such as the deck of a ship in a rough sea. Various embodiments of the present invention are especially suited to unmanned aircraft of small size. These embodiments allow for a fully automated operations cycle, whereby the aircraft can be repeatedly launched, retrieved, serviced, and re-launched, without manual intervention at any point, and while requiring only modest accuracy in piloting.
2. Description of Problem
Hovering aircraft, be they helicopters, thrust-vectoring jets, “tail-sitters”, or other types, usually land by gently descending in free thrust-borne flight onto a landing surface, coming to rest on an undercarriage of wheels, skids, or legs. This elementary technique can be problematic in certain situations, such as when targeting a small, windswept landing pad on a ship moving in a rough sea. Decades ago, the Beartrap or RAST system was developed to permit retrieval with acceptable safety in such conditions. Retrieval with this system involves securing a line between a helicopter and landing deck, and then winching the helicopter down onto a trolley. The helicopter is fastened to the trolley. After retrieval, the trolley is used to move the helicopter along the deck. The system is effective and widely used, but requires an expensive and substantial plant in the landing area, as well as manual operations coordinated between helicopter and shipboard crew. Furthermore, the helicopter must carry a complete undercarriage in addition to the necessary Beartrap components.
Desirable improvements relative to the Beartrap system include (a) simplification of the apparatus, and (b) automated rather than manual operation. Ideally not only would retrieval but also subsequent refueling and launch would be automated. This would be particularly desirable for an unmanned aircraft, whose operations cycle could then be made fully autonomous. Some experimental work toward this objective has been done for a hovering aircraft, as described in the publication by Mullens et at, titled, “Automated Launch, Recovery, and Refueling for Small Unmanned Aerial Vehicles” (2004); however, success has been limited even with light wind and a stationary base. The present invention by contrast provides for fully automated operation in calm or rough conditions, using apparatus which is simple, portable, and suitable for a small vessel or similarly confined base.
SUMMARY
In one embodiment of the method of the present invention, an aircraft would proceed automatically from free thrust-borne flight to retrieval to launch through the following sequence of actions:
(a) while approaching a base at low relative speed, the aircraft drops a weighted cable; (b) the aircraft then flies over a retrieval apparatus, which brings the cable into an aperture of cable guides, which in one embodiment forms the shape of a V in the horizontal or substantially horizontal plane; (c) further translation pulls the cable into and through a slot at the terminus of the cable guides, which captures the cable; (d) the aircraft is then anchored; (e) if the cable is not captured, the aircraft can climb away and return for another approach; (f) the aircraft, recognizing capture of the cable by an increase in tension, winches-in the cable and so draws itself into a docking receptacle, such as, in one embodiment, a funnel-like receptacle at the vertex of the cable guides; (g) as the aircraft is drawn into the docking receptacle, guiding surfaces align and ultimately mate the aircraft with one or more connectors for docking and servicing; (h) the cable is released from the retrieval apparatus, and retracted by the aircraft; (i) the aircraft is shut-down, refueled and otherwise serviced as necessary through one or more suitable connectors; (j) the aircraft completes launch preparations, and develops sufficient thrust to accelerate away from the retrieval apparatus when released; and (k) the aircraft is released into thrust-borne free flight.
Since loads can be low during retrieval from hover, the apparatus can be light and portable. Furthermore, easy targeting makes the technique well-suited for both manual control and economical automation.
It should be appreciated that the apparatus of various embodiments of the present invention include an aircraft docking assembly attached to an aircraft, a base retrieval apparatus attached to a stationary or movable base, and the combination of these configured so as to accomplish the methods of the present invention.
Additional features and advantages are described herein, and will be apparent from the following Detailed Description and the Figures.
BRIEF DESCRIPTION OF THE FIGURES
FIGS. 1A , 1 B, 1 C and 1 D are a series of diagrammatic rear-quarter perspective views of an embodiment of the present invention for a helicopter, illustrating an aircraft docking assembly attached to the helicopter, a base retrieval apparatus or servicing station, and the helicopter sequentially entering, capturing, docked in, and launching from the base retrieval apparatus or servicing station.
FIG. 2 is an enlarged partially fragmentary perspective view of a the base retrieval apparatus or servicing station for capturing, docking, servicing, and launching a helicopter.
FIGS. 3A , 3 B, 3 C and 3 D are a series of diagrammatic rear-quarter perspective views of an embodiment of the present invention for a hovering “tail-sitter” aircraft, illustrating an aircraft docking assembly attached to the aircraft, a base retrieval apparatus or servicing station, and the aircraft sequentially entering, capturing, docked in, and launching from the base retrieval apparatus or servicing station.
FIG. 4 is an enlarged perspective view of a representative docking probe mounted in the tail of a. “tail-sitter” aircraft of one embodiment of the present invention.
FIG. 5 is a perspective view of a representative aircraft as in FIG. 4 being pulled into a docking receptacle of the base retrieval apparatus of one embodiment of the present invention.
FIGS. 6A , 6 B, 6 C and 6 D are a series of diagrammatic rear-quarter perspective views of an embodiment of the present invention for a hovering aircraft, illustrating a possible downwind retrieval and launch sequence.
DETAILED DESCRIPTION
Various embodiments of the present invention are generally directed to apparatus and methods for retrieving a flying object or an aircraft from substantially thrust-borne free flight. In one embodiment, the apparatus includes an aircraft docking assembly for a helicopter and a base retrieval apparatus attachable to a stationary Or movable base. In another embodiment, the apparatus includes an aircraft docking assembly for an aircraft configured for efficient wing-borne flight and a base retrieval apparatus attachable to a stationary or movable base. It should be appreciated that the present invention is not limited to the embodiments illustrated in the figures and described below, and that in alternative embodiments, the shape, size, configuration and/or arrangement of one or more of the various components described below may vary. It should also be appreciated that the present invention need not include each and every of the components in the embodiments illustrated in the figures and described below.
Referring now to FIGS. 1A , 1 B, 1 C, 1 D and 2 , one embodiment of the aircraft docking assembly and base retrieval apparatus for a helicopter are generally illustrated. The base retrieval apparatus includes a base station 5 having a base fuel tank 12 and a base member 33 extending upwardly from the base fuel tank 12 . The base station 5 may include an azimuthal pivot 21 , as described below, in the illustrated embodiment, the base station 5 also includes support member 34 connected to the base member 33 for supporting a base docking device, fixture or probe receiver 11 . A guide, funnel, or funnel like docking receptacle 9 is attached to, and extends upwardly from, the base docking device, fixture or probe receiver 11 . The guide, funnel, or funnel like docking receptacle 9 includes guiding surfaces. The guide, funnel, or funnel like docking receptacle 9 has or defines a slot 10 configured to admit a cable 2 , as discussed below. The support member 34 includes outwardly extending arms 4 . The arms 4 extend outwardly defining an angle. A slot 6 is defined or placed near the vertex of the arms 4 . Aerodynamic surfaces or members 22 may be respectively attached to the arms 4 .
In one of the illustrated embodiments, the aircraft docking assembly is attached to the helicopter and includes a cable 2 , a cable point or fixture such as a cable end fitting 3 , a cable length reducer such as a winch 7 , and an aircraft docking device or fixture such as a probe 8 . The probe includes guiding surfaces and is substantially cylindrically shaped in one embodiment. The probe 8 is attached to the helicopter and extends beyond the skids 26 of the helicopter. At least a portion of the cable 2 is configured to be wound around a drum of the winch 7 . In another embodiment, the winch 7 is attached to the base retrieval apparatus as described below.
More specifically, FIGS. 1A , 1 B, 1 C and 1 D show an illustrative embodiment of the present invention, as used with the helicopter 1 of conventional layout. In preparation for retrieval, the helicopter 1 deploys the lightweight cable 2 weighted by the cable end fitting 3 , and drags it between the arms 4 of the base station 5 . If the helicopter's path falls within a capture envelope—determined by, primarily, the length 1 a , vertex angle ψa, and droop angle εa of the arms, and the length 1 c of the cable (and associated height of the servicing apparatus)—then the cable is guided into a cable holder configured to hold the cable 2 (through the slot 6 located at the vertex of the arms 4 as shown in FIG. 2 ). The helicopter pulls the cable through the slot 6 until further motion is restrained by the cable end fitting 3 . The cable end fitting thus anchors the helicopter. In various embodiments, the cable end fitting, cable, or slot may be made compliant to limit shock loading. If the helicopter's path is such that the cable misses the arms entirely, or is pulled over an arm before reaching the slot 6 , then the helicopter simply continues in free flight, and can return for another approach.
Once the helicopter is anchored it can increase thrust, and the cable will tend to stay nearly vertical despite disturbances. The helicopter's position can also be regulated by appropriate control, for example of rotor thrust and in-plane moments.
The constraint imposed by the anchored cable can be recognized by the helicopter, and used to trigger the next retrieval step. This involves pulling the helicopter downward toward the base docking device, fixture or probe receiver 11 , for example by activating a winch 7 on the helicopter or on the base station. In one embodiment, this causes the probe 8 on the helicopter to enter, and to be guided to the base of, the guide, funnel, or funnel like docking receptacle 9 on the base station. In one embodiment, the funnel incorporates a cable aperture such as a slot 10 to admit the cable, and thus allow for close placement of the cable and probe on the helicopter. The guide, funnel, or funnel like docking receptacle 9 guides the probe 8 to mate or match firmly with the base docking device, fixture or probe receiver 11 , thus completing the retrieval. Mating or matching can be detected by a suitable sensor in the probe or in the base docking device, fixture or probe receiver 11 .
Once retrieval is complete, the cable can be released from the capture slot, and optionally retracted into the helicopter. The helicopter's engine can be stopped. Servicing, such as provision of electrical power, refueling from a base supply, and weighing of the aircraft, can be effected through one or more suitable connectors and sensors in the probe 8 and base docking device, fixture or probe receiver 11 . The helicopter can remain docked until such time as launch is desired. These connectors can be configured to automatically transfer fluids and/or electricity to the aircraft.
For launch, appropriate self-testing can be completed, and the helicopter then run-up. Release into free flight should be permitted only when thrust is sufficient for positive separation. This condition can be enforced by various ways, such as an appropriately large break-out force in the docking fixture, or a suitable combination of thrust measurement and active triggering of an unlocking device (not shown). The aircraft would extract the cable from the docking fixture through the slot 10 and could then winch it onboard.
Referring now to FIGS. 3A , 3 B, 3 C, 3 D, 4 , 5 , 6 A, 6 B, 6 C and 6 D, one embodiment of an docking assembly and base retrieval apparatus for an aircraft configured for efficient wing-borne flight is generally illustrated. The aircraft includes a fixed wing 17 , a propeller 18 , a fuselage 31 , and an empennage 20 . The empennage 20 includes vertical stabilizer 27 and horizontal stabilizers 28 . The aircraft docking assembly includes cable 2 , cable end fitting 3 , aircraft docking device or fixture such as a probe 8 , and winch 7 . In another embodiment, the winch 7 is attached to the base retrieval apparatus as described below. The probe 8 may include fuel and electrical connectors 13 located at an end portion of the probe 8 . A cable guide 32 may be included to guide the cable as it is wound from the drum of the winch 7 in the illustrated embodiment, such a cable guide 32 is formed in the shape of a funnel.
The illustrated base retrieval apparatus for an aircraft configured for efficient wing-borne flight includes base station 5 having a base fuel tank 12 and a base member 33 extending upwardly from the base fuel tank 12 . The base station 5 also includes support member 34 connected to the base member 33 for supporting a base docking device, fixture or probe receiver 11 . The guide, funnel, or funnel like docking receptacle 9 is replaced by guide or docking receptacle 19 , having edges 35 that serve to admit and orient the empennage surfaces 27 and 28 of the aircraft as it is pulled into base docking device, fixture or probe receiver 11 , as discussed below. The support member 34 includes arms 4 . The arms 4 extend outwardly defining an angle. A slot 6 is defined or placed near the vertex of the arms 4 . Aerodynamic surfaces or members 22 may be respectively attached to a portion of the arms 4 . In one embodiment, the base station 5 may include an azimuthal pivot 21 , as described below.
FIG. 3 shows the aircraft 16 having a configuration suited to efficient wing-borne flight. A propeller 18 is installed at its nose, with the propeller's spin axis aligned with the fuselage 31 . The winch 7 and probe 8 , which are comparable to those in FIGS. 1A , B, 1 C and 1 D and FIG. 2 , are mounted at the rear of the fuselage 31 , as shown in more detail by FIG. 4 and described above. To prepare for retrieval, the aircraft pitches up from wing-borne flight, with its thrust line near horizontal, into thrust-borne flight, with its thrust line near vertical. Rotor thrust is adjusted to balance aircraft weight. The cable 2 is then deployed, and retrieval proceeds much as was described for the helicopter of FIGS. 1A , 1 B, 1 C and 1 D and FIG. 2 . In this case, however, the guide or docking receptacle 9 of FIGS. 1A , 1 B, 1 C and 1 D and FIG. 2 is replaced by a guide or docking receptacle 19 in the form of a set of petals whose edges 35 serve to admit and orient the empennage surfaces 27 and 28 of the aircraft as its probe 8 is pulled into the base docking device, fixture or probe receiver 11 , as illustrated by FIG. 5 . Thus, the combination of an appropriately long cable 2 , appropriately open arms 4 , and appropriately shaped petals, permits successful retrieval across a wide range of aircraft approach paths and orientations. After retrieval, the aircraft can be serviced and re-launched much as was described for the helicopter of FIGS. 1A , 1 B, 1 C and 1 D and FIG. 2 .
For automated retrieval, the aircraft and base retrieval apparatus each can be equipped with a suitable device for measuring relative position and velocity in three dimensions, such as satellite-navigation equipment having antennas on the aircraft 14 and on a reference point such as point 15 near the base docking device, fixture or probe receiver 11 . In an embodiment, each of the aircraft and base retrieval apparatus can also have equipment for measurement of orientation, such as magnetic or inertial sensors, as well as appropriate mechanisms for computation, power supply, and communication.
Communication between the aircraft and base retrieval apparatus can also be used, for example, to trigger the base retrieval apparatus to release the cable in the event of an anomaly, such as an excessive mismatch in position or orientation as the aircraft is pulled toward the base docking device, fixture or probe receiver 11 . In that case, the aircraft would fly clear of the base station and could return for another approach.
In many cases, the preferred approach direction will vary with wind velocity. This can be accommodated by providing a base retrieval apparatus including a base station mounted on the azimuthal pivot 21 (as shown in FIG. 2 ). The base support member 34 could then be oriented or rotated by a suitable actuator on the pivot, or by the weathervane action of the suitably placed aerodynamic surfaces or members 22 .
In light to moderate wind, the preferred approach direction would typically be upwind. However, if the wind speed V W were to exceed the maximum airspeed V A,max at which an aircraft such as that shown in FIGS. 3A , 3 B, 3 C and 3 D could sustain level thrust-borne flight, then an upwind approach would be possible only while descending. For an approach in level flight, the procedure illustrated in FIGS. 6A , 613 , 6 C and 6 D would be used instead. In this case, the aircraft would fly into the wind at a designated airspeed V A , while drifting downwind toward the base station at speed (V W -V A ). Capture of the cable would proceed as described for FIGS. 1A , 1 B, 1 C and 1 D and FIGS. 3A , 3 B, 3 C and 3 D; however, once anchored, the aircraft would not be able to hover vertically above the base docking receptacle. Instead, the aircraft could hover, and so maintain line tension, only in a downwind kite-like position as shown in FIG. 6B .
To accommodate this situation, the base docking device, fixture or probe receiver and the guide or docking receptacle may be mounted on a gimbal 23 so that the axis of the funnel can align with the cable, as shown in FIG. 6B . The gimbal could be set as desired after the aircraft mated to the base docking device, fixture or probe receiver, typically to thrust-vertical orientation. The torque necessary thus to orient the gimbal can be provided by the aircraft itself, or by an actuator on the base station. Once set at the desired orientation, the gimbal can be locked in place by an appropriate mechanism.
For launch in a strong wind, a downwind gimbal tilt ma likewise be necessary for the aircraft to accelerate out of the base docking device, fixture or probe receiver upon release. In preparation for such a downwind launch, the gimbal can be unlocked and tilted as appropriate. The aircraft can then pull itself out of the base docking device, fixture or probe receiver as shown in FIG. 6C . Once clear, the aircraft could reorient if desired to reduce the downwind drift rate, as shown in FIG. 6D . An anemometer 24 on the base station can be used to select the appropriate orientation for launch.
It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present subject matter and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims. | Various embodiments of the present disclosure provide an apparatus configured to automatically retrieve, service, and launch an aircraft. For retrieval, the aircraft drops a weighted cable, and pulls it at low relative speed into a broad aperture of the apparatus. In certain instances, the cable is dragged along guiding surfaces of the apparatus into and through a slot until its free end is captured. The aircraft becomes anchored to the apparatus, and is pulled downward by the cable into a receptacle. Guiding surfaces of the receptacle adjust the position and orientation of a probe on the aircraft, directing the probe to mate with a docking fixture of the apparatus. Once mated, the aircraft is automatically shut down and serviced. When desired, the aircraft is automatically started and tested in preparation for launch, and then released into free flight. A full ground-handling cycle is thus accomplished with a simple, economical apparatus. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation-in-part of U.S. application Ser. No. 10/158,216, filed on May 31, 2002. The '216 application claims the benefit of U.S. provisional application No. 60/294,588, filed on Jun. 1, 2001.
FIELD OF THE INVENTION
[0002] The present invention is directed to pharmaceutical compositions that provide for the coordinated release of an acid inhibitor and a non-steroidal anti-inflammatory drug (NSAID). These compositions have a reduced likelihood of causing unwanted side effects, especially gastrointestinal side effects, when administered as a treatment for pain, arthritis and other conditions amenable to treatment with NSAIDs.
BACKGROUND OF THE INVENTION
[0003] Although non-steroidal anti-inflammatory drugs are widely accepted as effective agents for controlling pain, their administration can lead to the development of gastroduodenal lesions, e.g., ulcers and erosions, in susceptible individuals. It appears that a major factor contributing to the development of these lesions is the presence of acid in the stomach and upper small intestine of patients. This view is supported by clinical studies demonstrating an improvement in NSAID tolerability when patients are also taking independent doses of acid inhibitors ( Dig. Dis. 12:210-222 (1994); Drug Safety 21:503-512 (1999); Aliment. Pharmacol. Ther. 12:135-140 (1998); Am. J. Med. 104(3A):67S-74S (1998); Clin. Ther. 17:1159-1173 (1995)). Other major factors contributing to NSAID-associated gastropathy include a local toxic effect of NSAIDs and inhibition of protective prostaglandins ( Can. J. Gastroenterol. 13:135-142 (1999) and Pract. Drug Safety 21:503-512, (1999)), which may also make some patients more susceptible to the ulcerogenic effects of other noxious stimuli.
[0004] In general, more potent and longer lasting acid inhibitors, such as proton pump inhibitors, are thought to be more protective during chronic administration of NSAIDs than shorter acting agents, e.g., histamine H 2 receptor antagonists (H-2 blockers) ( N. Eng. J. Med. 338:719-726 (1998); Am. J. Med. 104(3A):56S-61S (1998)). The most likely explanation for this is that gastric pH fluctuates widely throughout the dosing interval with short acting acid inhibitors leaving the mucosa vulnerable for significant periods of time. In particular, the pH is at its lowest point, and hence the mucosa is most vulnerable, at the end of the dosing interval (least amount of acid inhibition) and for some time after the subsequent dose of acid inhibitor. In general, it appears that when a short acting acid inhibitor and an NSAID are administered simultaneously, NSAID-related mucosal damage occurs before the pH of the gastrointestinal tract can be raised and after the acid inhibiting effect of the short acting acid inhibitor dissipates.
[0005] Although longer lasting agents, such as proton pump inhibitors (PPIs), usually maintain a consistently higher gastroduodenal pH throughout the day, their antisecretory effect may be delayed for several hours and may not take full effect for several days ( Clin. Pharmacokinet. 20:38-49 (1991)). Their effect may be diminished toward the end of the usual dosing interval. Intragastric pH rises particularly slowly with the first dose in a course of treatment since this class of drugs is enteric coated to avoid destruction by stomach acid. As a result, absorption is delayed for several hours. Even then, some patients fail to respond consistently to drugs of this type and suffer from “acid breakthrough” which again leaves them vulnerable to NSAID-associated gastroduodenal damage ( Aliment. Pharmacol. Ther. 14:709-714 (2000)). Despite a significant reduction in gastroduodenal lesions with the concomitant administration of a proton pump inhibitor during six months of NSAID therapy, up to 16% of patients still develop ulcers, indicating that there remains substantial room for improvement ( N. Eng. J. Med. 338:727-734 (1998)). Thus, the addition of a pH sensitive enteric coating to an NSAID could provide additional protection against gastroduodenal damage not provided by the H2 blocker or PPI alone. In addition, although long acting acid inhibitors may reduce the risk of GI lesions in chronic NSAID users, there are questions about the safety of maintaining an abnormally elevated pH in a patient's GI tract for a prolonged period of time ( Scand. J. Gastroenterol. Suppl. 178:85-92 (1990)).
[0006] Recognizing the potential benefits of PPIs for the prevention of NSAID-induced gastroduodenal damage, others have disclosed strategies for combining the two active agents for therapeutic purposes. However, these suggestions do not provide for coordinated drug release or for reducing intragastric acid levels to a non-toxic level prior to the release of NSAID (U.S. Pat. No. 5,204,118; U.S. Pat. No. 5,417,980; U.S. Pat. No. 5,466,436; and U.S. Pat. No. 5,037,815). In certain cases, suggested means of delivery would expose the gastrointestinal tract to NSAIDs prior to onset of PPI activity (U.S. Pat. No. 6,365,184).
[0007] Attempts to develop NSAIDs that are inherently less toxic to the gastrointestinal tract have met with only limited success. For example, the recently developed cyclooxygenase-2 (COX-2) inhibitors show a reduced tendency to produce gastrointestinal ulcers and erosions, but a significant risk is still present, especially if the patient is exposed to other ulcerogens ( JAMA 284:1247-1255 (2000); N. Eng. J. Med. 343:1520-1528 (2000)). In this regard, it appears that even low doses of aspirin will negate most of the benefit relating to lower gastrointestinal lesions. In addition, the COX-2 inhibitors may not be as effective as other NSAIDs at relieving some types of pain and have been associated with significant cardiovascular problems ( JADA 131:1729-1737 (2000); SCRIP 2617, pg. 19, Feb. 14, 2001); NY Times, May 22, 2001, pg. C1)).
[0008] Other attempts to produce an NSAID therapy with less gastrointestinal toxicity have involved the concomitant administration of a cytoprotective agent. In 1998, Searle began marketing Arthrotec™ for the treatment of arthritis in patients at risk for developing GI ulcers. This product contains misoprostol (a cytoprotective prostaglandin) and the NSAID diclofenac. Although patients administered Arthrotec™ do have a lower risk of developing ulcers, they may experience a number of other serious side effects such as diarrhea, severe cramping and, in the case of pregnant women, potential damage to the fetus.
[0009] Another approach has been to produce enteric coated NSAID products. However, even though these have shown modest reductions in gastroduodenal damage in short term studies ( Scand. J. Gastroenterol. 20: 239-242 (1985) and Scand. J. Gastroenterol. 25:231-234 (1990)), there is no consistent evidence of a long term benefit during chronic treatment.
[0010] Overall, it may be concluded that the risk of inducing GI ulcers is a recognized problem associated with the administration of NSAIDs and that, despite considerable effort, an ideal solution has not yet been found.
SUMMARY OF THE INVENTION
[0011] The present invention is based upon the discovery of a new method for reducing the risk of gastrointestinal side effects in people taking NSAIDs for pain relief and for other conditions, particularly during chronic treatment. The method involves the administration of a single, coordinated, unit-dose product that combines: a) an agent that actively raises intragastric pH to levels associated with less risk of NSAID-induced ulcers; and b) an NSAID that is specially formulated to be released in a coordinated way that minimizes the adverse effects of the NSAID on the gastroduodenal mucosa. Either short or long acting acid inhibitors can be effectively used in the dosage forms. This method has the added benefit of being able to protect patients from other gastrointestinal ulcerogens whose effect may otherwise be enhanced by the disruption of gastroprotective prostaglandins due to NSAID therapy.
[0012] In its first aspect, the invention is directed to a pharmaceutical composition in unit dosage form suitable for oral administration to a patient. The composition contains an acid inhibitor present in an amount effective to raise the gastric pH of a patient to at least 3.5, preferably to at least 4, and more preferably to at least 5, when one or more unit dosage forms are administered. The gastric pH should not exceed 7.5 and preferably should not exceed 7.0. The term “acid inhibitor” refers to agents that inhibit gastric acid secretion and increase gastric pH. In contrast to art teaching against the use of H2 blockers for the prevention of NSAID-associated ulcers (N. Eng. J. Med. 340:1888-1899 (1999)), these agents are preferred compounds in the current invention. Specific H2 blockers that may be used include cimetidine, ranitidine, ebrotidine, pabutidine, lafutidine, loxtidine or famotidine. The most preferred acid inhibitor is famotidine present in dosage forms in an amount of between 5 mg and 100 mg.
[0013] Other preferred agents that may be effectively used as acid inhibitors are the proton pump inhibitors such as omeprazole, esomeprazole, pantoprazole, lansoprazole, rabeprazole, pariprazole, leminoprazole and tenatoprazole. Examples of particular proton pump inhibitors include omeprazole, present in unit dosage forms in an amount of between 5 mg and 50 mg; lansoprazole, present in unit dosage forms in an amount of between 5 mg and 150 mg (and preferably at between 5 mg and 30 mg); and pantoprazole, present in unit dosage forms in an amount of between 10 mg and 200 mg. Recently, a newer class of acid inhibitor has been developed which competes with potassium at the acid pump. The compounds in this class have been referred to as “reversible proton pump inhibitors” or “acid pump antagonists” and may also be used in the present invention. Examples include AZD-0865, AR-H047108, CS-526, pumaprazole, revaprazan and soraprazan (see WO9605177 and WO9605199). Other compounds in this group are H-335/25 (AstraZeneca, Dialog file 128, accession number 020806); Sch-28080 (Schering Plough, Dialog file 128, accession number 009663); Sch-32651 (Schering Plough, Dialog file 128, accession number 006883) and SK&F-96067 (CAS Registry no. 115607-61-9).
[0014] The pharmaceutical composition also contains a non-steroidal anti-inflammatory drug in an amount effective to reduce or eliminate pain or inflammation. The NSAID may be celecoxib, rofecoxib, lumiracoxib, valdecoxib, parecoxib, etoricoxib, CS-502, JTE-522, L-745,337, NS398, aspirin, acetaminophen (considered to be an NSAID for the purposes of the present invention), ibuprofen, flurbiprofen, ketoprofen, naproxen, oxaprozin, etodolac, indomethacin, ketorolac, lornoxicam, meloxicam, piroxicam, droxicam, tenoxicam, nabumetone, diclofenac, meclofenamate, mefenamic acid, diflunisal, sulindac, tolmetin, fenoprofen, suprofen, benoxaprofen, aceclofenac, tolfenamic acid, oxyphenbutazone, azapropazone, and phenylbutazone. The most preferred NSAID is naproxen in an amount of between 50 mg and 1500 mg, and more preferably, in an amount of between 200 mg and 600 mg. It will be understood that, for the purposes of the present invention, reference to an acid inhibitor, NSAID, or analgesic agent will include all of the common forms of these compounds and, in particular, their pharmaceutically acceptable salts. The amounts of NSAIDs which are therapeutically effective may be lower in the current invention than otherwise found in practice due to potential positive kinetic interaction and NSAID absorption in the presence of an acid inhibitor.
[0015] Preferably, the pharmaceutical composition of the present invention is in the form of a tablet or capsule that has: (a) the acid inhibitor present in an amount effective to raise the gastric pH of a patient to at least 3.5 upon the administration of one or more unit dosage forms; and (b) the non-steroidal anti-inflammatory drug (NSAID) present in an amount effective to reduce or eliminate pain or inflammation in a patient upon administration of one or more of said unit dosage forms. The NSAID in the dosage form should be in a core, preferably a single core when tablets are used, that is surrounded by a coating that does not release NSAID until the pH of the surrounding medium is 3.5 or higher. In the case of capsules, there may be several cores of NSAID, i.e., there may be multiple particles, each being surrounded by a coating that does not release NSAID until the pH of the surrounding medium is 3.5 or higher. The acid inhibitor is in one or more layers outside of the core which do not contain any NSAID. These layers are not surrounded by an enteric coating and, upon ingestion of the tablet or capsule by a patient, release the acid inhibitor into the patient's stomach.
[0016] The term “unit dosage form” as used herein refers to a single entity for drug administration. For example, a single tablet or capsule combining both an acid inhibitor and an NSAID would be a unit dosage form. A unit dosage form of the present invention preferably provides for coordinated drug release in a way that elevates gastric pH and reduces the deleterious effects of the NSAID on the gastroduodenal mucosa, i.e., the acid inhibitor is released first and the release of NSAID is delayed until after the pH in the GI tract has risen.
[0017] In a preferred embodiment, the unit dosage form is a multilayer tablet, having an outer layer comprising the acid inhibitor and an inner core which comprises the NSAID. In the most preferred form, coordinated delivery is accomplished by having the inner core surrounded by a polymeric barrier coating that does not dissolve unless the surrounding medium is at a pH of at least 3.5, preferably at least 4 and more preferably, at least 5. Alternatively, a barrier coating may be employed which controls the release of NSAID by time, as opposed to pH, with the rate adjusted so that NSAID is not released until after the pH of the gastrointestinal tract has risen to at least 3.5, preferably at least 4, and more preferably at least 5. Thus, a time-release formulation may be used to prevent the gastric presence of NSAID until mucosal tissue is no longer exposed to the damage enhancing effect of very low pH.
[0018] One NSAID of special interest in dosage forms is aspirin which not only provides relief from pain and inflammation but may also be used in low doses by patients to reduce the risk of stroke, heart attack and other conditions. Thus, pharmaceutical compositions may contain an acid inhibitor in combination with aspirin in an amount effective, upon the administration of one or more unit dosage forms, to achieve any of these objectives. As with the compositions described above the unit dosage form can be a tablet or capsule in which aspirin is present in a core and is surrounded by a coating that does not release the aspirin until the pH of the surrounding medium is 3.5 or higher. The acid inhibitor is in one or more layers outside the core, which do not include an NSAID, are not surrounded by an enteric coating; and, upon ingestion of the dosage form by a patient, release the acid inhibitor into the patient's stomach. Any of the acid inhibitors described herein may be used in the aspirin-containing dosage forms. In dosage forms designed for providing low dose aspirin therapy to patients, the aspirin should typically be present at 20-200 mg.
[0019] The invention includes methods of treating a patient for pain, inflammation and/or other conditions by administering the pharmaceutical compositions described above. Although the method may be used for any condition in which an NSAID is effective, it is expected that it will be particularly useful in patients with osteoarthritis or rheumatoid arthritis. Other conditions that may be treated include, but are not limited to: all forms of headache, including migraine headache; acute musculoskeletal pain; ankylosing spondylitis; dysmenorrhoea; myalgias; and neuralgias.
[0020] In a more general sense, the invention includes methods of treating pain, inflammation and/or other conditions by orally administering an acid inhibitor at a dose effective to raise a patient's gastric pH to at least 3.5, preferably to at least 4 or and more preferably to at least 5. The patient is also administered an NSAID, for example in a coordinated dosage form, that has been coated in a polymer that only dissolves at a pH of at least 3.5, preferably at least 4 and, more preferably, 5 or greater or which dissolves at a rate that is slow enough to prevent NSAID release until after the pH has been raised. When acid inhibitor and NSAID are administered in separate doses, e.g., in two separate tablets, they should be given concomitantly (i.e., so that their biological effects overlap) and may be given concurrently, i.e., NSAID is given within one hour after the acid inhibitor. Preferably, the acid inhibitor is an H2 blocker and, in the most preferred embodiment, it is famotidine at a dosage of between 5 mg and 100 mg. Proton pump inhibitors may also be used and offer advantages in terms of duration of action. Any of the NSAIDs described above may be used in the method but naproxen at a dosage of between 200 and 600 mg is most preferred. It is expected that the acid inhibitor and analgesic will be typically delivered as part of a single unit dosage form which provides for the coordinated release of therapeutic agents. The most preferred dosage form is a multilayer tablet having an outer layer comprising an H2 blocker or a proton pump inhibitor and an inner core comprising an NSAID.
[0021] The invention also provides a method for increasing compliance in a patient requiring frequent daily dosing of NSAIDs by providing both an acid inhibitor and NSAID in a single convenient, preferably coordinated, unit dosage form, thereby reducing the number of individual doses to be administered during any given period.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1 is a schematic diagram of a four layer tablet dosage form. There is a naproxen core layer surrounded by a barrier layer. A third, enteric coating, layer delays the release of naproxen sodium until the pH is at a specific level, e.g., above 4. Finally, there is an outer layer that releases an acid inhibitor such as famotidine.
[0023] FIG. 2 illustrates a three layer dosage form. An acid inhibitor, e.g., famotidine, is released immediately after ingestion by a patient in order to raise the pH of the gastrointestinal tract to above a specific pH, e.g., above 4. The innermost layer contains naproxen. Thus, the dosage form has a naproxen core, an enteric film coat and an acid inhibitor film coat.
[0024] FIG. 3 illustrates a naproxen sodium pellet which contains a subcoat or barrier coat prior to the enteric film coat.
DETAILED DESCRIPTION OF THE INVENTION
[0025] The present invention is based upon the discovery of improved pharmaceutical compositions for administering NSAIDs to patients. In addition to containing one or more NSAIDs, the compositions include acid inhibitors that are capable of raising the pH of the GI tract of patients. All of the dosage forms are designed for oral delivery and provide for the coordinated release of therapeutic agents, i.e., for the sequential release of acid inhibitor followed by analgesic.
[0026] The NSAIDs used in preparations may be either short or long acting. As used herein, the term “long acting” refers to an NSAID having a pharmacokinetic half-life of at least 2 hours, preferably at least 4 hours and more preferably, at least 8-14 hours. In general, its duration of action will equal or exceed about 6-8 hours. Examples of long-acting NSAIDs are: flurbiprofen with a half-life of about 6 hours; ketoprofen with a half-life of about 2 to 4 hours; naproxen or naproxen sodium with half-lives of about 12 to 15 hours and about 12 to 13 hours respectively; oxaprozin with a half life of about 42 to 50 hours; etodolac with a half-life of about 7 hours; indomethacin with a half-life of about 4 to 6 hours; ketorolac with a half-life of up to about 8-9 hours, nabumetone with a half-life of about 22 to 30 hours; mefenamic acid with a half-life of up to about 4 hours; and piroxicam with a half-life of about 4 to 6 hours. If an NSAID does not naturally have a half-life sufficient to be long acting, it can, if desired, be made long acting by the way in which it is formulated. For example, NSAIDs such as acetaminophen and aspirin may be formulated in a manner to increase their half-life or duration of action. Methods for making appropriate formulations are well known in the art (see e.g. Remington's Pharmaceutical Sciences, 16 th ed., A. Oslo editor, Easton, Pa. (1980)).
[0027] It is expected that a skilled pharmacologist may adjust the amount of drug in a pharmaceutical composition or administered to a patient based upon standard techniques well known in the art. Nevertheless, the following general guidelines are provided:
Indomethacin is particularly useful when contained in tablets or capsules in an amount from about 25 to 75 mg. A typical daily oral dosage of indomethacin is three 25 mg doses taken at intervals during the day. However, daily dosages of up to about 150 mg are useful in some patients. Aspirin will typically be present in tablets or capsules in an amount of between about 250 mg and 1000 mg. Typical daily dosages will be in an amount ranging from 500 mg to about 10 g. However, low dose aspirin present at 20-200 mg (and preferably 40-100 mg) per tablet or capsule may also be used. Ibuprofen may be provided in tablets or capsules of 50, 100, 200, 300, 400, 600, or 800 mg. Daily doses should not exceed 3200 mg. 200 mg-800 mg may be particularly useful when given 3 or 4 times daily. Flurbiprofen is useful when in tablets at about from 50 to 100 mg. Daily doses of about 100 to 500 mg, and particularly from about 200 to 300 mg, are usually effective. Ketoprofen is useful when contained in tablets or capsules in an amount of about 25 to 75 mg. Daily doses of from 100 to 500 mg and particularly of about 100 to 300 mg are typical as is about 25 to 50 mg every six to eight hours. Naproxen is particularly useful when contained in tablets or capsules in an amount of from 250 to 500 mg. For naproxen sodium, tablets of about 275 or about 550 mg are typically used. Initial doses of from 100 to 1250 mg, and particularly 350 to 800 mg are also used, with doses of about 550 mg being generally preferred. Oxaprozin may be used in tablets or capsules in the range of roughly 200 mg to 1200 mg, with about 600 mg being preferred. Daily doses of 1200 mg have been found to be particularly useful and daily doses should not exceed 1800 mg or 26 mg/kg. Etodolac is useful when provided in capsules of 200 mg to 300 mg or in tablets of about 400 mg. Useful doses for acute pain are 200-400 mg every six-eight hours, not to exceed 1200 mg/day. Patients weighing less than 60 kg are advised not to exceed doses of 20 mg/kg. Doses for other uses are also limited to 1200 mg/day in divided doses, particularly 2, 3 or 4 times daily. Ketorolac is usefully provided in tablets of 1-50 mg, with about 10 mg being typical. Oral doses of up to 40 mg, and particularly 10-30 mg/day have been useful in the alleviation of pain. Nabumetone may be provided in tablets or capsules of between 500 mg and 750 mg. Daily doses of 1500-2000 mg, after an initial dose of 100 mg, are of particular use. Mefenamic acid is particularly useful when contained in tablets or capsules of 50 mg to 500 mg, with 250 mg being typical. For acute pain, an initial dosage of 1-1000 mg, and particularly about 500 mg, is useful, although other doses may be required for certain patients. Lornoxicam is provided in tablets of 4 mg or 8 mg. Useful doses for acute pain are 8 mg or 16 mg daily, and for arthritis are 12 mg daily.
[0040] Other NSAIDs that may be used include: celecoxib, rofecoxib, meloxicam, piroxicam, droxicam, tenoxicam, valdecoxib, parecoxib, etoricoxib, CS-502, JTE-522, L-745,337, or NS398. JTE-522, L-745,337 and NS398 as described, inter alia, in Wakatani, et al. ( Jpn. J. Pharmacol. 78:365-371 (1998)) and Panara, et al. ( Br. J. Pharmacol. 116:2429-2434 (1995)). The amount present in a tablet or administered to a patient will depend upon the particular NSAID being used. For example:
Celecoxib may be administered in a tablet or capsule containing from about 100 mg to about 500 mg or, preferably, from about 100 mg to about 200 mg. Piroxicam may be used in tablets or capsules containing from about 10 to 20 mg. Rofecoxib will typically be provided in tablets or capsules in an amount of 12.5, or 50 mg. The recommended initial daily dosage for the management of acute pain is 50 mg. Meloxicam is provided in tablets of 7.5 mg, with a recommended daily dose of 7.5 or 15 mg for the management of osteoarthritis. Valdecoxib is provided in tablets of 10 or 20 mg, with a recommended daily dose of 10 mg for arthritis or 40 mg for dysmenorrhea.
[0046] With respect to acid inhibitors, tablets or capsules may contain anywhere from 1 mg to as much as 1 g. Typical amounts for H2 blockers are: cimetidine, 100 to 800 mg/unit dose; ranitidine, 50-300 mg/unit dose; famotidine, 5-100 mg/unit dose; ebrotidine 400-800 mg/unit dose; pabutidine 40 mg/unit dose; lafutidine 5-20 mg/unit dose; and nizatidine, 50-600 mg/unit dose. Proton pump inhibitors will typically be present at about 5 mg to 600 mg per unit dose. For example, the proton pump inhibitor omeprazole should be present in tablets or capsules in an amount from 5 to 50 mg, with about 10 or 20 mg being preferred. Other typical amounts are: esomeprazole, 5-100 mg, with about 40 mg being preferred; lansoprazole, 5-150 mg (preferably 5-50 mg), with about 7.5, 15 or 30 mg being most preferred; pantoprazole, 10-200 mg, with about 40 mg being preferred; and rabeprazole, 5-100 mg, with about 20 mg being preferred.
[0047] Making of Pharmaceutical Preparations
[0048] The pharmaceutical compositions of the invention include tablets, dragees, liquids and capsules and can be made in accordance with methods that are standard in the art (see, e.g., Remington's Pharmaceutical Sciences, 16 th ed., A Oslo editor, Easton, Pa. (1980)). Drugs and drug combinations will typically be prepared in admixture with conventional excipients. Suitable carriers include, but are not limited to: water; salt solutions; alcohols; gum arabic; vegetable oils; benzyl alcohols; polyethylene glycols; gelatin; carbohydrates such as lactose, amylose or starch; magnesium stearate; talc; silicic acid; paraffin; perfume oil; fatty acid esters; hydroxymethylcellulose; polyvinyl pyrrolidone; etc. The pharmaceutical preparations can be sterilized and, if desired, mixed with auxiliary agents such as: lubricants, preservatives, disintegrants; stabilizers; wetting agents; emulsifiers; salts; buffers; coloring agents; flavoring agents; or aromatic substances.
[0049] Enteric coating layer(s) may be applied onto the core or onto the barrier layer of the core using standard coating techniques. The enteric coating materials may be dissolved or dispersed in organic or aqueous solvents and may include one or more of the following materials: methacrylic acid copolymers, shellac, hydroxypropylmethcellulose phthalate, polyvinyl acetate phthalate, hydroxypropylmethylcellulose trimellitate, carboxymethylethyl-cellulose, cellulose acetate phthalate or other suitable enteric coating polymer(s). The pH at which the enteric coat will dissolve can be controlled by the polymer or combination of polymers selected and/or ratio of pendant groups. For example, dissolution characteristics of the polymer film can be altered by the ratio of free carboxyl groups to ester groups. Enteric coating layers also contain pharmaceutically acceptable plasticizers such as triethyl citrate, dibutyl phthalate, triacetin, polyethylene glycols, polysorbates or other plasticizers. Additives such as dispersants, colorants, anti-adhering and anti-foaming agents may also be included.
[0050] The Making of Tablet Dosage Forms
[0051] Preferably, the combination of an acid inhibitor and an NSAID will be in the form of a bi- or multi-layer tablet. In a bilayer configuration, one portion of the tablet contains the acid inhibitor in the required dose along with appropriate excipients, agents to aid dissolution, lubricants, fillers, etc. The second portion of the tablet will contain the NSAID, preferably naproxen, in the required dose along with other excipients, dissolution agents, lubricants, fillers, etc. In the most preferred embodiment, the NSAID layer is surrounded by a polymeric coating which does not dissolve at a pH of less than 4. The NSAID may be granulated by methods such as slugging, low- or high-shear granulation, wet granulation, or fluidized-bed granulation. Of these processes, slugging generally produces tablets of less hardness and greater friability. Low-shear granulation, high-shear granulation, wet granulation and fluidized-bed granulation generally produce harder, less friable tablets.
EXAMPLES
Example 1
Enteric Coated Naproxen Sodium Core and Famotidine Immediate Release
[0052] A schematic diagram of a four layer tablet dosage form is shown in FIG. 1 . The first layer contains naproxen sodium distributed throughout a matrix of pharmaceutically acceptable fillers, excipients, binding agents, disintegrants, and lubricants.
[0053] The second layer is a barrier layer which protects the first layer containing naproxen sodium. The barrier film coat is applied by conventional pan coating technology and the weight of the barrier coat may vary from 1% to 3% of the core tablet weight. In particular embodiments, the core naproxen sodium tablet is coated with coating ingredients such as Opaspray® K-1-4210A or Opadry® YS-1-7006 (Colorcon, West Point, Pa.). Polymer film coating ingredients such as hydroxypropylmethylcellulose 2910 and polyethylene glycol 8000 in a coating suspension may also be used.
[0054] The function of the third layer is to prevent the release of naproxen sodium until the dosage form reaches an environment where the pH is above about 4 or 5. The enteric coating does not dissolve in areas of the GI tract where the pH may be below about 4 or 5 such as in an unprotected stomach. Methacrylic acid copolymers are used as the enteric coating ingredient, triethyl citrate and dibutyl phthalate are plasticizers, and ammonium hydroxide is used to adjust the pH of the dispersion. The coating dissolves only when the local pH is above, for example, 5.5 and, as a result, naproxen sodium is released.
[0055] The outermost layer contains an “acid inhibitor” in an effective amount which is released from the dosage form immediately after administration to the patient. The acid inhibitor in the present example is a proton pump inhibitor or, preferably the H2 blocker famotidine, which raises the pH of the gastrointestinal tract to above 4. The typical effective amount of famotidine in the dosage form will vary from 5 mg to 100 mg. A typical film coating formulation contains Opadry Clear® YS-1-7006 which helps in the formation of the film and in uniformly distributing famotidine within the fourth layer without tablets sticking to the coating pan or to each other during application of the film coat. Other ingredients may include: plasticizers such as triethyl citrate, dibutyl phthalate, and polyethylene glycol; anti-adhering agents such as talc; lubricating ingredients such as magnesium stearate; and opacifiers such as titanium dioxide. In addition, the pH of the film coating solution can be adjusted to aid in dissolution of the famotidine. The film coating is thin and rapidly releases famotidine for absorption.
[0000]
Core Tablet Ingredients
% W/W
mg/Tablet
Naproxen sodium, USP
74.074
500.00
Microcrystalline cellulose, NF
17.166
115.87
(Avicel PH 200)
Povidone (K29/32), USP
3.450
23.29
Talc, USP
4.350
29.36
Magnesium Stearate, NF
0.960
6.48
Total
100.00
675.00
[0000]
Barrier Film Coating Ingredients
% W/W
Opadry Clear ® YS-1-7006
5.00
Purified water USP
95.00
Total
100.00
[0000]
Enteric Coating Dispersion Ingredients
% W/W
Methacrylic Acid Copolymer, NF
7.30
(Eudragit L-100-55)
Methacrylic Acid Copolymer, NF
7.30
(Eudragit L-100)
Triethyl Citrate, NF
2.95
Dibutyl Phthalate, NF
1.17
Ammonium Hydroxide (30%), NF
0.87
Purified water, USP
80.41
Total
100.00
[0000]
Famotidine Coating Dispersion Ingredients
% W/W
Famotidine, USP
3.0
Opadry Clear ® (YS-1-7006)
5.0
Talc, USP
3.0
Purified Water, USP
89.0
Total
100.0
Example 2
Enteric Coated Naproxen Core and Famotidine Immediate Release
[0056] FIG. 2 illustrates a three layered dosage form which releases famotidine immediately after ingestion by the patient in order to raise the pH of the gastrointestinal tract to above about 4. The innermost layer contains naproxen uniformly distributed throughout a matrix of pharmaceutically acceptable excipients. These excipients perform specific functions and may serve as binders, disintegrants, or lubricants. A pharmaceutically acceptable enteric coating surrounds the naproxen core. The function of the enteric coat is to delay the release of naproxen until the dosage form reaches an environment where the pH is above about 4. The coating does not dissolve in the harshly acidic pH of the unprotected stomach. It contains methacrylic acid copolymers which prevent the release of naproxen in the unprotected stomach. Also included are: triethyl citrate, a plasticizer; simethicone emulsion, an anti-foaming agent; and sodium hydroxide which is used to adjust the pH of the dispersion.
[0057] The outermost layer contains an “acid inhibitor” in an effective amount which is released from the dosage form immediately after administration to the patient. The acid inhibitor in this example is a proton pump inhibitor or, preferably, the H2 blocker famotidine which raises the pH of the stomach to above 4. A typical film coating formulation contains Opadry Clear® YS-1-7006 which helps in the formation of the film and in uniformly distributing famotidine in the fourth layer without tablets sticking to the coating pan or sticking to each other during application of the film coat. Other ingredients are: plasticizers such as polyethylene glycol 8000; anti-adhering agents such as talc; lubricating ingredients such as magnesium stearate; and opacifiers such as titanium dioxide. In addition, the pH of the film coating solution can be adjusted to aid in dissolution of the famotidine. The film coating is thin and rapidly releases famotidine for absorption.
[0000]
Core Tablet Ingredients
% W/W
mg/Tablet
Naproxen, USP
90.91
500.00
Povidone K-90, USP
2.00
11.00
Starch, USP
2.59
14.25
Croscarmellose Sodium, USP
4.00
22.00
Magnesium Stearate, NF
0.50
2.75
Total
100.00
550.00
Purified Water, USP qs
[0000]
Enteric Coating Dispersion Ingredients
% W/W
Methacrylic Acid Copolymer Type C, NF
14.5
(Eudragit L-100-55)
Talc, USP
3.8
Sodium Hydroxide, NF
0.2
Triethyl Citrate, NF
1.7
Simethicone Emulsion, USP
0.02
Purified Water, USP
79.78
Total
100.00
[0000]
Famotidine Coating Dispersion Ingredients
% W/W
Famotidine, USP
3.0
Opadry Clear ® (YS-1-7006)
5.0
Talc, USP
3.0
Purified Water, USP
89.0
Total
100.0
Example 3
Naproxen Controlled Release Core and Famotidine Immediate Release
[0058] A trilayer tablet which separates famotidine contained in the film coat from controlled-release naproxen may be used in the present invention. The core tablet of naproxen is formulated using excipients which control the drug release for therapeutic relief from pain and inflammation for 24 hours. FIG. 2 shows an example of an appropriate trilayer tablet. In this particular example, naproxen is mixed with a polymeric material, hydroxypropyl-methylcellulose and granulated with water. The granules are dried, milled, and blended with a lubricant, such as magnesium stearate. They are then compacted into tablets.
[0059] The controlled-release core tablet of naproxen is film coated with a pharmaceutically acceptable enteric coating. The function of the enteric coat is to delay the release of naproxen until the dosage form reaches an environment where the pH is above about 4. The coating does not dissolve in the extremely acidic pH of the unprotected stomach. The function of methacrylic acid copolymers is to prevent the release of naproxen until the pH of the stomach rises. Triethyl citrate is a plasticizer, simethicone emulsion is a anti-foaming agent, and sodium hydroxide is used to adjust the pH of the dispersion.
[0060] The outermost layer contains an “acid inhibitor” which is released from the dosage form immediately after administration to the patient. The acid inhibitor in the present example is a proton pump inhibitor or, preferably, the H2 blocker famotidine which consistently raises the pH of the stomach to above 4. The typical effective amount of famotidine in the dosage will vary from 5 mg to 100 mg. A typical film coating formulation contains Opadry Blue® YS-1-4215 which is essential for film formation and for the uniform application of famotidine to the core tablet. Polymer film coating ingredients, hydroxypropylmethylcellulose or Opaspray® K-1-4210A (Colorcon, West Point, Pa.) may also be used. Other ingredients which help in the formation of the film and in the uniform application of famotidine to the core tablet are: plasticizers such as triethyl citrate and dibutyl phthalate; anti-adhering agents such as talc; lubricating ingredients such as magnesium stearate; and opacifiers such as titanium dioxide. In addition, the pH of the film coating solution can be adjusted to aid in dissolution of the famotidine. The film coating is thin and rapidly releases famotidine for absorption.
[0000]
Core Tablet Ingredients
% W/W
mg/Tablet
Naproxen, USP
94.00
750
Hydroxypropyl methylcellulose
5.00
39.9
2208, USP (viscosity 15000 cps)
Magnesium Stearate, NF
1.00
7.95
Total
100.00
797.85
[0000]
Enteric Coating Dispersion Ingredients
% W/W
Methacrylic Acid Copolymer Type C, NF
14.5
(Eudragit L-100-55)
Talc, USP
3.8
Sodium Hydroxide, NF
0.2
Triethyl Citrate, NF
1.7
Simethicone Emulsion, USP
0.02
Purified Water, USP
79.78
Total
100.00
[0000]
Famotidine Coating Dispersion Ingredients
% W/W
Famotidine, USP
2.0
Opadry Blue ® (YS-1-4215)
10.0
Talc, USP
9.0
Purified Water, USP
79.0
Total
100.0
Example 4
Naproxen and Famotidine Controlled Release Core and Famotidine Immediate Release
[0061] A trilayer tablet which separates famotidine contained in the film coat from controlled-release naproxen and famotidine may be used in the present invention. The core tablet of naproxen and famotidine is formulated using excipients which control the drug release for therapeutic relief from pain and inflammation for 24 hours. FIG. 2 is an example of an appropriate trilayer tablet. In this particular example, naproxen and famotidine are mixed with a polymeric material, hydroxypropylmethylcellulose and granulated with water. The granules are dried, milled, and blended with a lubricant, such as magnesium stearate. They are then compacted into tablets.
[0062] The controlled-release core tablet of naproxen and famotidine is film coated with a pharmaceutically acceptable enteric coating. The function of the enteric coat is to delay the release of naproxen until the dosage form reaches an environment where the pH is above about 4. The coating does not dissolve in the extremely acidic pH of the unprotected stomach. The function of methacrylic acid copolymers is to prevent the release of naproxen until the pH of the stomach rises. Triethyl citrate is a plasticizer, simethicone emulsion is a anti-foaming agent, and sodium hydroxide is used to adjust the pH of the dispersion
[0063] The outermost later contains an “acid inhibitor” which is released from the dosage form immediately after administration to the patient. The acid inhibitor in the present example is a proton pump inhibitor or, preferably, the H2 blocker famotidine which consistently raises the pH of the stomach to above 4. The typical effective amount of famotidine in the dosage will vary from 5 mg to 100 mg. A typical film coating formulation contains Opadry Blue® YS-1-4215 which is essential for film formation and for the uniform application of famotidine to the core tablet. Polymer film coating ingredients, hydroxypropylmethylcellulose or Opaspray® K-1-4210A (Colorcon, West Point, Pa.) may also be used. Other ingredients which help in the formation of the film and in the uniform application of famotidine to the core tablet are: plasticizers such as triethyl citrate and dibutyl phthalate; anti-adhering agents such as talc; lubricating ingredients such as magnesium stearate; and opacifiers such as titanium dioxide. In addition, the pH of the film coating solution can be adjusted to aid in dissolution of the famotidine. The film coating is thin and rapidly releases famotidine for absorption.
[0000]
Core Tablet Ingredients
% W/W
mg/Tablet
Naproxen, USP
88.05
500
Famotidine, USP
3.52
20.0
Hydroxypropyl methylcellulose
7.03
39.9
2208, USP (viscosity 15000 cps)
Magnesium Stearate, NF
1.40
7.95
Total
100.00
567.85
[0000]
Enteric Coating Dispersion Ingredients
% W/W
Methacrylic Acid Copolymer Type C, NF
14.5
(Eudragit L-100-55)
Talc, USP
3.8
Sodium Hydroxide, NF
0.2
Triethyl Citrate, NF
1.7
Simethicone Emulsion, USP
0.02
Purified Water, USP
79.78
Total
100.00
[0000]
Famotidine Coating Dispersion Ingredients
% W/W
Famotidine, USP
2.0
Opadry Blue ® (YS-1-4215)
10.0
Talc, USP
9.0
Purified Water, USP
79.0
Total
100.0
Example 5
Enteric Coated Naproxen Sodium Core and Pantoprazole Immediate Release in Film Coat
[0064] A schematic diagram of a four layer tablet dosage form is shown in FIG. 1 . The first layer contains naproxen sodium distributed throughout a matrix of pharmaceutically acceptable fillers, excipients, binding agents, disintegrants, and lubricants.
[0065] The second layer is a barrier layer which protects the first layer containing naproxen sodium. The barrier film coat is applied by conventional pan coating technology and the weight of the barrier coat may vary from 1% to 3% of the core tablet weight. In particular embodiments, the core naproxen sodium tablet is coated with coating ingredients such as Opaspray® K-1-4210A or Opadry® YS-1-7006 (Colorcon, West Point, Pa.). Polymer film coating ingredients such as hydroxypropylmethylcellulose 2910 and polyethylene glycol 8000 in a coating suspension may also be used.
[0066] The third layer is an enteric film coat. It does not dissolve in areas of the GI tract where the pH may be below 4 such as in an unprotected stomach but it dissolves only when the local pH is above about 4. Therefore, the function of the third layer is to prevent the release of naproxen sodium until the dosage form reaches an environment where the pH is above 4. In this example, hydroxypropylmethylcellulose phthalate is the enteric coating ingredient, cetyl alcohol is a plasticizer and acetone and alcohol are solvents.
[0067] The fourth layer contains an “acid inhibitor” in an effective amount which is released from the dosage form as soon as the film coat dissolves. The acid inhibitor in this example is a proton pump inhibitor, pantoprazole, which raises the pH of the gastrointestinal tract to above 4. The typical effective amount of pantoprazole in the dosage form may vary from 10 mg to 200 mg. The film coat is applied by conventional pan coating technology and the weight of film coat may vary from 4% to 8% of the core tablet weight. Other ingredients are, plasticizers such as triethyl citrate, dibutyl phthalate, anti-adhering agents such as talc, lubricating ingredients such as magnesium stearate, opacifiers such as, titanium dioxide, and ammonium hydroxide to adjust the pH of the dispersion. The film coating is thin and rapidly releases pantoprazole for absorption. Therefore, pantoprazole releases first and then the core erodes and releases naproxen sodium.
[0000]
Core Tablet Ingredients
% W/W
mg/tablet
Naproxen sodium, USP
74.075
500.00
Microcrystalline cellulose, NF
17.165
115.87
(Avicel PH 200)
Povidone (K29/32), USP
3.450
23.29
Talc, USP
4.350
29.36
Magnesium Stearate, NF
0.960
6.48
Total
100.00
675.00
[0068] Naproxen sodium, 50% microcrystalline cellulose and povidone are dry mixed and wet granulated in an appropriate granulator with sufficient purified water. The wet granules are dried, milled, and blended with the remaining 50% microcrystalline cellulose, talc and magnesium stearate. The final granule blend is compressed into tablets.
[0000]
Barrier Film Coating Ingredients
% W/W
Opadry ® Clear YS-1-7006
5.00
Purified Water, USP
95.00
Total
100.00
[0069] Opadry clear is added slowly to purified water and mixing is continued until Opadry is fully dispersed. The solution is sprayed on to the tablet cores in a conventional coating pan until proper amount of Opadry clear is deposited on the tablets.
[0000]
Enteric Coating Ingredients
% W/W
Hydroxypropyl methylcellulose phthalate, NF
5.5
Cetyl alcohol, NF
0.3
Acetone, NF
66.3
Alcohol, USP
27.9
Total
100.00
[0070] Hydroxypropylmethylcellulose phthalate and cetyl alcohol are dissolved in a mixture of alcohol and acetone. The solution is then sprayed on to the tablet bed in proper coating equipment. A sample of the tablets is tested for gastric resistance and the coating stopped if the tablets pass the test.
[0000]
Pantoprazole Film Coating Ingredients
% W/W
Pantoprazole sodium, USP
5.00
Opadry ® Clear YS-1-7006
5.00
Sodium carbonate, NF
1.20
Purified Water, USP
88.80
Total
100.00
[0071] Pantoprazole sodium is dissolved in purified water containing sodium carbonate in solution. After thorough mixing, Opadry clear is added slowly and mixing is continued until Opadry is fully dispersed. The suspension is sprayed on to the tablet cores in a conventional coating pan until the proper amount of pantoprazole sodium is deposited.
Example 6
Enteric Coated Naproxen Sodium Core and Omeprazole Immediate Release in Film Coat
[0072] A schematic diagram of a four layer tablet dosage form is shown in FIG. 1 . The first layer contains naproxen sodium distributed throughout a matrix of pharmaceutically acceptable fillers, excipients, binding agents, disintegrants, and lubricants.
[0073] The second layer is a barrier layer which protects the first layer containing naproxen sodium. The barrier film coat is applied by conventional pan coating technology and the weight of the barrier coat may vary from 1% to 3% of the core tablet weight. In particular embodiments, the core naproxen sodium tablet is coated with coating ingredients such as Opaspray® K-1-4210A or Opadry® YS-1-7006 (Colorcon, West Point, Pa.). Polymer film coating ingredients such as hydroxypropylmethylcellulose 2910 and polyethylene glycol 8000 in a coating suspension may also be used.
[0074] The third layer is an enteric film coat. It does not dissolve in areas of the GI tract where the pH is below 4 such as in an unprotected stomach but it dissolves only when the local pH is above 4. Therefore, the function of the third layer is to prevent the release of naproxen sodium until the dosage form reaches an environment where the pH is above about 4. In this example, hydroxypropylmethylcellulose phthalate is the enteric coating ingredient, cetyl alcohol is a plasticizer and acetone and alcohol are solvents.
[0075] The fourth layer contains an “acid inhibitor” in an effective amount which is released from the dosage form as soon as the film coat dissolves. The acid inhibitor in this example is a proton pump inhibitor, omeprazole, which raises the pH of the gastrointestinal tract to above 4. The typical effective amount of omeprazole in the dosage form may vary from 5 mg to 50 mg. The film coat is applied by conventional pan coating technology and the weight of film coat may vary from 4% to 8% of the core tablet weight. Other ingredients are, plasticizers such as triethyl citrate, dibutyl phthalate, anti-adhering agents such as talc, lubricating ingredients such as magnesium stearate, opacifiers such as, titanium dioxide, and ammonium hydroxide to adjust the pH of the dispersion. The film coating is thin and rapidly releases omeprazole for absorption. Therefore, omeprazole is released first and then the core erodes and releases naproxen sodium.
[0000]
Core Tablet Ingredients
% W/W
mg/tablet
Naproxen sodium, USP
74.075
500.00
Microcrystalline cellulose, NF
17.165
115.87
(Avicel PH 200)
Povidone (K29/32), USP
3.450
23.29
Talc, USP
4.350
29.36
Magnesium Stearate, NF
0.960
6.48
Total
100.00
675.00
[0076] Naproxen sodium, 50% microcrystalline cellulose and povidone are dry mixed and wet granulated in an appropriate granulator with sufficient purified water. The wet granules are dried, milled, and blended with the remaining 50% microcrystalline cellulose, talc and magnesium stearate. The final granule blend is compressed into tablets.
[0000]
Barrier Film Coating Ingredients
% W/W
Opadry ® Clear YS-1-7006
5.00
Purified Water, USP
95.00
Total
100.00
[0077] Opadry clear is added slowly to purified water and mixing is continued until Opadry is fully dispersed. The solution is sprayed on to the tablet cores in a conventional coating pan until the proper amount of Opadry clear is deposited on the tablets.
[0000]
Enteric Coating Ingredients
% W/W
Methacrylic Acid Copolymer, NF
6.0
(Eudragit L-100-55)
Triethyl Citrate, NF
0.6
Talc, USP
3.0
Purified Water, USP
5.0
Isopropyl Alcohol, USP
85.40
Total
100.00
[0078] Methacrylic acid copolymer, triethyl citrate, and talc are dissolved in a mixture of isopropyl alcohol and water. The solution is then sprayed on to the tablet bed in a proper coating equipment. A sample of the tablets is tested for gastric resistance and the coating is stopped if the tablets pass the test.
[0000]
Omeprazole Film Coating Ingredients
% W/W
Omeprazole, USP
5.00
Opadry ® Clear YS-1-7006
5.00
Purified Water, USP
10.00
Isopropyl Alcohol, USP
80.00
Total
100.00
[0079] Omeprazole is dissolved in a purified water and isopropyl alcohol mixture. After thorough mixing, Opadry clear is added slowly and mixing is continued until Opadry is fully dispersed. The suspension is sprayed on to the tablet cores in a conventional coating pan until proper amount of omeprazole is deposited on the tablets.
Example 7
Naproxen Sodium Delayed Release and Omeprazole Immediate Release Capsule
[0080] A coordinated delivery dosage may be used to provide fast release of an acid inhibitor, a proton pump inhibitor, omeprazole which raises the pH of the gastrointestinal tract to above 4, and the delayed release of a non-steroidal anti-inflammatory drug, naproxen sodium. Omeprazole granules modify the pH of the stomach such that the drug readily dissolves and is absorbed in the stomach without significant degradation. The typical effective amount of omeprazole in the dosage form may vary from 5 mg to 50 mg. The release of naproxen sodium is delayed by enteric coating.
[0081] Omeprazole granules contain an alkalizing excipient such as sodium bicarbonate. Other soluble alkalizing agents such as potassium bicarbonate, sodium carbonate, sodium hydroxide, or their combinations may also be used. The alkalizing agent helps solubilize and protect omeprazole from degradation before its absorption. Sodium lauryl sulfate helps in the wetting of omeprazole. Other surfactants may be used to perform the same function. In the present example, hydroxypropyl methylcellulose helps in granule formation, sodium starch glycolate is a disintegrant, and magnesium stearate is a lubricant. Other excipients may also be used to perform these functions.
[0082] Naproxen sodium pellets as shown in FIG. 3 are prepared by the wet massing technique and the conventional extrusion and spheronization process. The excipients used in the formulation are microcrystalline cellulose, and povidone. The pellets after drying and classification are coated with a protective subcoating containing povidone. Other coating ingredients may also be used such as Opaspray K-1-4210A or Opadry YS-1-7006 (trademarks of Colorcon, West Point, Pa.). Polymer film coating ingredients such as hydroxypropylmethylcellulose 2910 and polyethylene glycol 8000 in a subcoating suspension are also alternatives. Other ingredients are, plasticizers such as triethyl citrate, dibutyl phthalate, anti-adhering agents such as talc, lubricating ingredients such as magnesium stearate, opacifiers such as, titanium dioxide.
[0083] The subcoated pellets are enteric coated using enteric coating polymers. In this example, the enteric coating polymer is methacrylic acid copolymer and the plasticizer is dibutyl phthalate which are dissolved in a mixture of acetone and alcohol. The enteric film does not dissolve in the acidic pH but dissolves when the pH in the gut is above about pH 6 and releases naproxen sodium.
[0000]
mmmOmeprazole Granules
% W/W
mg/capsule
Omeprazole, USP
12.9
20.00
Sodium Bicarbonate, USP
82.40
127.72
Hydroxypropyl methylcellulose, USP
2.00
3.10
Sodium lauryl sulfate, NF
0.20
0.31
Sodium starch glycolate, NF
2.00
3.10
Magnesium stearate, NF
0.50
0.77
Total
100
100
[0084] Hydroxypropylmethylcellulose is dissolved in water, then sodium lauryl sulfate is added and the solution is mixed. Omeprazole, microcrystalline cellulose, and sodium bicarbonate are dry mixed together and granulated with the granulating solution. The granulation is mixed until proper granule formation is reached. The granulation is then dried, milled, and blended with magnesium stearate.
[0000]
Pellet Ingredients
% W/W
mg/tablet
Naproxen sodium, USP
86.80
250.00
Microcrystalline cellulose, NF
11.10
32.00
(Avicel PH 200)
Povidone (K90), USP
2.10
6.00
Total
100.00
288.00
[0085] Povidone is dissolved in water. Naproxen sodium and microcrystalline cellulose are dry mixed and granulated with povidone solution. The wet mass is mixed until proper consistency is reached. The wet mass is then pressed through an extruder and spheronized to form pellets. The pellets are then dried and classified into suitable particle size range.
[0000]
Subcoat Ingredients
% W/W
Povidone (K29-32), USP
10.00
Alcohol, USP
90.00
Total
100.00
[0086] The pellet cores are coated using povidone solution by a conventional coating pan method to a weight gain of 1-2%.
[0000]
Enteric Coating Ingredients
% W/W
Methacrylic Acid Copolymer, NF
8.20
(Eudragit L-100)
Diethyl Phthalate, NF
1.70
Acetone, NF
33.30
Isopropyl Alcohol, USP
56.80
Total
100.0
[0087] Eudragit L-100 is dissolved in isopropanol and acetone and diethyl phthalate is dissolved. The solution is sprayed on the pellet cores using proper film coating equipment. A sample of the pellets is tested for gastric resistance before stopping the coating process.
[0088] Omeprazole fast release granules and naproxen sodium delayed release pellets are blended together and filled into appropriate size capsules to contain 250 mg naproxen sodium and 20 mg omeprazole per capsule.
Example 8
Naproxen Delayed Release and Omeprazole Immediate Release Capsule
[0089] The present Example is directed to a coordinated delivery dosage form containing omeprazole and naproxen. The formulation contains 10 mg omeprazole and uses methylcellulose as a binder and croscarmellose sodium as a disintegrant. Naproxen pellets as shown in FIG. 3 do not need a subcoating layer and are enteric coated with an aqueous dispersion of methacrylic acid copolymer. Optionally, these pellets could be compressed into a core and film coated with an acid inhibitor and thereby form a bilayer tablet.
[0000]
Omeprazole Granules
% W/W
mg/capsule
Omeprazole, USP
6.45
10.00
Sodium Bicarbonate, USP
88.85
137.71
Methylcellulose, USP
2.00
3.10
Sodium lauryl sulfate, NF
0.20
0.31
Croscarmellose sodium, NF
2.00
3.10
Magnesium stearate, NF
0.50
0.78
Total
100
100
[0090] Methylcellulose is dissolved in water, then sodium lauryl sulfate is added to the solution and mixed. Omeprazole, microcrystalline cellulose, and sodium bicarbonate are dry mixed together and granulated with the granulating solution. The granulation is mixed until proper granule formation is reached. The granulation is then dried, milled, and blended with magnesium stearate.
[0000]
Pellet Ingredients
% W/W
mg/tablet
Naproxen, USP
76.
250.00
Microcrystalline cellulose, NF
21.
71.44
(Avicel PH 200)
Povidone (K90), USP
2.
6.56
Total
100.
328.00
[0091] Povidone is dissolved in water. Naproxen and microcrystalline cellulose are dry mixed and granulated with povidone solution. The wet mass is mixed until proper consistency is reached. The wet mass is then pressed through an extruder and spheronized to form pellets. The pellets are then dried and classified into a suitable particle size range.
[0000]
Enteric Coating Ingredients
% W/W
Methacrylic Acid Copolymer, NF
15.60
(Eudragit L30D 30% dispersion)
Talc, USP
7.60
Triethyl citrate, NF
1.60
Simethicone Emulsion, USP
0.20
(Silicone antifoam emulsion SE 2)
Purified Water, USP
74.80
[0092] Eudragit 30D is dispersed in purified water and simethicone emulsion. Talc and triethyl citrate are then dispersed. The suspension is sprayed on the pellet cores using proper film coating equipment. A sample of the pellets is tested for gastric resistance before stopping the coating process. Omeprazole fast release granules and naproxen sodium delayed release pellets are blended together and filled into appropriate size capsules to contain 250 mg naproxen and 10 mg omeprazole per capsule.
Example 9
Clinical Study of the Relationship of Gastric pH to NSAID-Induced Gastric Ulcers
[0093] Sixty-two subjects were enrolled in a clinical study and randomly assigned to three groups. The following three groups were administered study medication twice daily for five days: (a) 550 mg naproxen sodium (n=10), (b) 40 mg famotidine given with 550 mg of naproxen or famotidine followed 90 minutes later by 550 mg naproxen, (n=39) or (c) 20 mg omeprazole followed by 550 mg naproxen sodium (n=13). Gastric pH was measured hourly beginning at the time of dosing of the final daily dose of study medication and for 8-10 hours thereafter. Subjects had a gastric endoscopy performed at the beginning and on Day 5 prior to the morning dose of study medication to identify gastric and duodenal irritation; no subjects were admitted to the study if gastric irritation was present at the time of initial endoscopy.
[0094] Five patients, three (33%) in the naproxen alone group and two (5%) in the famotidine/naproxen group, presented with gastroduodenal ulcers at the end of the study. In the naproxen alone group, the pH was greater than 4 only 4% of the time, and in the famotidine/naproxen group the pH was greater than 4 forty-nine percent of the time during the 8-10 hours following naproxen sodium dosing. Additionally, Lanza grade 3 or 4 damage was present in 28% (n=11) of the subjects receiving famotidine/naproxen sodium, and present 100% (n=10) in the naproxen sodium treatment group. Monitoring of gastric acidity on day 5 indicated that patients with Lanza scores of greater than 2 had integrated gastric acidity of greater than 100 mmol-hr./L. Only 20-40% of patients with integrated gastric acidity of less than 100 mmol-hr/L had gastric pathology, whereas all patients with integrated gastric acidity greater than 100 mmol-hr/L had pathology.
Example 10
Famotidine and Enteric Coated Naproxen Reduce Gastroduodenal Damage Due to NSAID Therapy
[0095] Thirty-seven patients were randomized to two groups for a one week study of twice-daily dosing of: 500 mg enteric coated naproxen, and 500 mg enteric coated naproxen preceded by 40 mg famotidine. Endoscopies were conducted on all patients prior to first dosing and on the final day of the study. No subjects had evidence of gastroduodenal damage at the beginning of the study (at first endoscopy).
[0096] At the second endoscopy, Lanza scores for gastroduodenal damage were assessed for all subjects. 39% of the subjects in the enteric coated naproxen 500 mg group had grade 3-4 gastroduodenal damage. This is lower than the percentage that would be expected for the administration of 500 mg of non-enteric naproxen based upon previous work. Nevertheless, subjects administered 500 mg enteric coated naproxen and 40 mg famotidine had an even lower incidence of grade 3-4 gastroduodenal damage (26%) than subjects who had previously taken enteric coated naproxen alone which demonstrates the value of combining acid inhibition with enteric coating of NSAID to minimize the gastrointestinal damage.
[0097] All references cited herein are fully incorporated by reference. Having now fully described the invention, it will be understood by those of skill in the art that the invention may be performed within a wide and equivalent range of conditions, parameters and the like, without affecting the spirit or scope of the invention or any embodiment thereof. | The present invention is directed to drug dosage forms that release an agent that raises the pH of a patient's gastrointestinal tract, followed by a non-steroidal anti-inflammatory drug. The dosage form is designed so that the NSAID is not released until the intragastric pH has been raised to a safe level. The invention also encompasses methods of treating patients by administering this coordinated release, gastroprotective, antiarthritic/analgesic combination unit dosage form to achieve pain and symptom relief with a reduced risk of developing gastrointestinal damage such as ulcers, erosions and hemorrhages. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a contrast medium injection device used for X-ray CT image diagnosis, MRI image diagnosis and the like.
2. Description of the Related Art
A contrast medium is used for the diagnosis of X-ray CT (computed tomography) images, MRI, angio-images (angiographic images) and the like. The contrast medium is a liquid having high viscosity and the injection thereof by means of a manual power takes a lot of time and labor so that in recent years automatic contrast medium injection devices have come to be used.
An automatic injection device 100 of FIG. 8 is an example of such devices, and since it can be mounted with two syringes, it is referred to as a double-head type. FIG. 9 shows a typical mechanism of the automatic injection device. A syringe 1 a for the contrast medium is set at the side of a head A, a syringe 1 b for a physiological saline solution is set at the side of a head B, and a Y-shaped tube 2 is connected to the tips of the two syringes. A catheter is connected to the tip of the Y-shaped tube and can be injected with the contrast medium and the physiological saline solution.
The physiological saline solution is used mainly for flushing inside the tube in order to prevent blood from coagulating inside the catheter and the tube after the contrast medium was injected. It is also used for the purpose of diluting the contrast medium.
As for the essential action of the device, injection of a required amount of the contrast medium is performed by forwarding a syringe piston of the head A while a syringe piston at the head B stopped, and then after the side of the head A is stopped, the side of the head B is moved forward to perform flushing with the physiological saline solution. In order to dilute the contrast medium, both cylinder pistons of the head A and the head B are moved forward so as to mix the liquid of both heads A and B in the Y-shaped tube (i.e. three way-branched tube).
In the automatic injection device of FIGS. 8 and 9 , rotations of motors 4 a , 4 b at the sides of the head A and the head B, respectively, are transferred to motor gears 6 a , 6 b via gear heads 5 a , 5 b , and transferred to screw gears 7 a , 7 b linked to ball screws 8 a , 8 b by being reduced to a predetermined gear ratio to rotate the ball screws 8 a , 8 b . Furthermore, the rotation is converted into a linear movement by ball nut units 9 a , 9 b which are engaged with the ball screws 8 a , 8 b so that piston holders 3 a , 3 b which hold the syringe pistons are allowed to move forward or backward.
However, since the contrast medium has high viscosity, and high pressure is necessary for the injection, specifically when the contrast medium is injected, the high pressure is also transferred to the side of the head B via the Y-shaped tube. Therefore, in the case of the device using a mechanism having an extremely small frictional factor such as that of the ball screw, there was the possibility that the syringe piston at the side of the head B is pushed and forced to move backward by high pressure and the contrast medium is sucked by the head B.
For this reason, an idea can be conceived that a valve is provided between the Y branch of the Y-shaped tube and the head B so that the valve is closed when the syringe piston at the head B is in a stopped state. However, when a manually operable valve is used for this purpose, the switching operation of the valves is complicated and the switching is sometimes forgotten. Although it is possible to perform the switching of the valves automatically and electrically, it is not preferable to provide a drive unit of such a switching in the midway through a substantially soft and light tube because the balance of the device configuration become worse.
On the other hand, if a one-way valve is used, the device can be made simple and compact, but the backward-moving action of the syringe piston cannot be performed. Although an idea can be also conceived that a pressure in the forward direction is applied to the syringe piston at the head B so as to resist the pressure from the side of the head A when the syringe piston at the head B is in a stopped state, the axis of rotation of the motor continues to be in a stopped state while electricity is being supplied to the motor, and there arises a problem of the seizing of the motor.
SUMMARY OF THE INVENTION
The present invention has been devised in order to solve such a problem and it is an object of the present invention to provide an automatic injection device mountable with a plurality of syringes, in which when at least one head is in a state of injection and at least one head is in a stopped state, the backward-moving of the cylinder piston of the stopped head is prevented so as to prevent liquid from undesirably being mixed and the amount thereof from unreliably being injected.
The present invention is directed to an automatic injection device comprising piston holders holding cylinder pistons and plural systems of heads having a drive mechanism for moving the piston holders forward and backward, whereby the device can hold a plurality of syringes and operates injection or suction in each syringe independently; said device comprising a backward-moving prohibition mechanism for prohibiting the backward-moving of the piston holder of a second head when the piston holder of a first head is in a forward-moving state and the piston holder of the second head is in a stopped state.
According to the present invention, when the syringe piston mounted at the second head is in a stopped state, even if the piston holder is moved forward for the injection of a chemical solution in the syringe at a the first head, the backward-moving of the syringe piston at the second head can be prevented. Therefore the chemical solution in the syringe of the first head does not flow into the syringe of the second head, thereby the mixture of the chemical solution can effectively prevented.
In the present invention, a “head” refers to a system of a syringe holding and driving mechanism which can hold a syringe and allow a syringe piston to move forward and backward in order to inject and suck the chemical solution and the like. The number of heads provided for the automatic injection device of the present invention is more than two and, though a plurality of heads may form an independent body of equipment, it is preferable that they are usually assembled into the same body of equipment. From among a plurality of heads, a head which allows preventing the unnecessary backward-moving of the piston holder is taken as a second head, and a head which causes the backward-moving of the piston holder of the second head is taken as a first head. Hence, in the case of a multi-head with the number of heads being more than three, a plurality of heads corresponding to the above described first or second head may sometimes exist. Moreover, there are some cases where one head can be the first head and yet the second head as well. That is, in relation to other heads, a certain head may be sometimes a first head during a certain action and may be a second head during a different action.
In a normal application, a double head type having two heads is used quite often and, in this case, the first head is most commonly used for injecting the contrast medium and the second head for injecting the physiological saline solution.
In case that this device is a multi-head type that holds a plurality of syringes, at least two of the tips of syringes may be connected using multi way-branched tube.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view showing an example of an automatic injection device using an electromagnetic brake.
FIG. 2 is a view showing an example of the automatic injection device using a disc brake.
FIG. 3 is a view showing an example of the automatic injection device using a ratchet (linear type).
FIG. 4 is a view showing the automatic injection device using a ratchet (wheel type).
FIG. 5 is an enlarged view of the wheel type ratchet.
FIG. 6 is a view showing an example of the automatic injection device using a worm reduction gear.
FIG. 7 is an enlarged view of a cylindrical worm gear.
FIG. 8 is a whole view of a double head type automatic injection device.
FIG. 9 is a view explaining a drive mechanism of a conventional automatic injection device.
DESCRIPTION OF SYMBOLS
1 a Syringe for Contrast Medium
1 b Syringe for Physiological saline Solution
2 Y-Shaped Tube
3 a , 3 b Piston Holder
4 a , 4 b Motor
5 a , 5 b Gear Head
6 a , 6 b Motor Gear
7 a , 7 b Screw Gear
8 a , 8 b Ball Screw
9 a , 9 b Ball Nut Unit
10 Frame Unit
11 Electromagnetic Brake
12 Disc Brake
13 Disc
14 Pad
15 Ratchet
16 Ratchet Pole
17 Rotary Solenoid
19 Cylinder Portion of Ball Nut Unit
21 Wheel Type Ratchet
22 Worm Reduction Gear
23 Cylindrical Worm
24 Worm Wheel
25 Cylindrical Worm Gear
100 Automatic Injection Device
DETAILED DESCRIPTION OF THE INVENTION
In general, in order to move a piston holder forward and backward, the above-described drive mechanism of the automatic injection device converts the rotational movement of a motor into a linear movement by using a ball screw and the like, as,described by reference to FIG. 9 . Hence, backward-moving prohibition mechanism can be provided in any portion of a transfer route from the motor to the piston holder. That is, depending on the specific embodiment of the invention, the backward-moving prohibition mechanism can be constituted such that either the rotation is prohibited or the linear movement is prohibited.
Referring to a double head type chemical solution injection device mountable with two syringes, a description will be made below. As shown in FIG. 9 , the syringe for a contrast medium is mounted on one side of a head A and the syringe for a physiological saline solution is mounted on the other side of a head B. In the same drawings described below, though only the head at the side of the physiological saline solution (at the side of the head B) will be shown, the head at the side of the contrast medium can be constituted similarly to the head at the side of the contrast medium as shown in FIG. 9 . In this case, the head A corresponds to the first head, and the head B corresponds to the second head. The head at the side of the contrast medium may also be provided with the backward-moving prohibition mechanism if necessary.
<Embodiment 1>
An example using an electromagnetic brake as backward-moving prohibition mechanism will be described below with reference to FIG. 1 .
In this example, the main body of the electromagnetic brake 11 is fixed to a frame unit 10 , while the axis (to which a screw gear 7 b is fixed) of a ball screw 8 b is fixed to an armature side of the electromagnetic brake. Linking and separation between the main body and the armature is performed by controlling the coil inside the electromagnetic brake.
When a syringe piston at the side of the head B is moved forward of backward, the main body and the armature are separated each other (i.e. contact is released), thereby the ball screw 8 b can rotate freely by receiving the rotation of a motor 4 b . When the electromagnetic brake is turned on, the main body and the armature is linked (i.e. contact is attained), thereby the rotation of the axis of the ball screw 8 b is fixed. Hence, if the electromagnetic brake is turned on when the syringe piston at the side of head B is in a stopped state and the syringe piston at the side of the head A is allowed to act, the syringe piston at the side of the head B does not move and there is no risk of sucking the contrast medium.
<Embodiment 2>
An example using a disc brake as backward-moving prohibition mechanism will be described below with reference to FIG. 2 .
The disc brake 12 has a disc 13 and pads 14 , which stops the rotation of the disc by holding the disc 13 between the pads 14 . When the piston syringe at the head B is moved forward and backward, the space between the disc 13 and the pads 14 is left open so that the motor gear 6 b can freely rotate. When the backward-moving of the syringe piston at the head B is desired to be prohibited, the disc 13 may be clamped by the pads 14 by electrically controlling the disc brake.
In this example, though the disc 13 is fixed to the motor gear 6 b , it may be fixed to the screw gear 7 b or fixed to any place of the axis of rotation.
In the above-described embodiments 1 and 2 , though a method of using the brake was described, other types of brakes other than the electromagnetic brake and the disc brake may be used if the movement in the backward direction can be prevented. Moreover, though the embodiments 1 and 2 are constituted such that the rotation is stopped, they may be also constituted such that the linear movement is stopped.
<Embodiment 3>
An example using a ratchet mechanism as the backward-moving prohibition mechanism will be described below with reference to FIG. 3 .
As shown in FIG. 3 ( a ), a ratchet 15 is provided on a cylinder portion 19 of a ball nut unit 9 b and fitted into a ratchet claw of a ratchet pole 16 , making it possible to move forward the syringe piston and prohibit the backward-moving thereof. That is, when at least the motor at the side of the head B is stopped and the ratchet is allowed to engage with the ratchet claw, there is no backward-moving of the syringe piston nor a backward flow. When the syringe piston allows to move backward, a rotary solenoid 17 is electrically controlled so as to rotate the ratchet pole 16 , and the engagement of the ratchet and the ratchet claw is released. In FIG. 3 ( b ) (cross-sectional view at line A-A in FIG. 3 ( a )), a state of the ratchet being engaged with the ratchet claw and a physical relationship of the rotary solenoid 17 are shown.
The place where the ratchet is provided is not limited to this example, and if it is provided on the member which makes reciprocating movement together with the syringe piston, such construction functions similarly to this example.
<Embodiment 4>
In the embodiment 3, the example using the linear type ratchet was shown, but in the embodiment 4, a wheel type ratchet 21 as shown in FIG. 5 is used. As shown in FIG. 4 , the wheel type ratchet 21 is fixed to a screw gear 7 b and is engaged with the ratchet pole 16 . Engagement and release of the ratchet is controlled by the rotary solenoid 17 .
In this example, the wheel type ratchet is fixed on the axis of a ball screw 8 b and prevents the ball screw 8 b from rotating in the backward direction when the syringe piston at the side of the head B is in a stopped state. However, the ratchet may be fixed on the axis of the motor 4 b.
<Embodiment 5>
In the devices of the embodiments 1 to 4, examples were shown wherein the rotational transmission route itself from the motor to the ball screw is the same as the conventional route shown in FIG. 9 and provided additionally with the backward-moving prohibition mechanism. In the embodiment 5, the improvement was placed in the rotational transmission route; that is, the transmission is made only in one way from the motor to the ball screw. That is, the transfer route is constituted such that the rotation (both forward and backward directions) of the motor is transferred to the ball screw, on the other hand, even if a force to rotate the ball screw is applied, the force does not incur the rotation of the motor axis.
In an example as shown in FIG. 6 , a worm reduction gear 22 using a worm gear is linked to the motor 4 b and reduces the rotation of the motor, at the same time the axis of motor is arranged such that it is not rotated by the rotational force from the side of the ball screw. Inside the worm reduction gear 22 , a cylindrical worm gear 25 comprising a cylindrical worm 23 and a worm wheel 24 is provided as shown in FIG. 7 , and the axis of motor is linked to the axis of the cylindrical worm 23 , and the central axis of the worm wheel 24 is linked to the axis of the motor gear 6 b . In this constitution, the rotation of the cylindrical worm 23 is transferred to the worm wheel 24 due to the characteristic of the cylindrical worm gear, but it is not possible to rotate the cylindrical worm 23 even if the wheel worm tries to rotate.
The constitution of the worm gear is not limited to this example. For example, the axis of the worm wheel 24 may be joined to the axis of the ball screw 8 b so as to be rotated by the cylindrical worm 23 .
As described above, according to the present invention, an automatic injection device mountable with a plurality of syringes can be provided wherein, when at least one head is in an injecting state and at least one head is in a stopped state, the backward-moving of the syringe piston of the stopped head is prevented so as to prevent liquid from being undesirably mixed and the injection amount thereof from becoming less accurate. | An automatic injection device has piston holders holding cylinder pistons and plural systems of heads having a drive mechanism for moving the piston holders forward and backward so that the device can hold a plurality of syringes and operates injection or suction in each syringe independently. This device also has a mechanism for prohibiting the backward-moving of the piston holder of a second head when the piston holder of a first head is in a forward-moving state and the piston holder of the second head is in a stopped state. This structure effectively prevents liquid from being undesirably mixed and the injection amount thereof from becoming less accurate. | 0 |
[0001] This application claims the benefit of French Application No. 03 01513 filed on Feb. 7, 2003 and U.S. Provisional Application No. 60/459,623 filed on Apr. 3, 2003, the entire disclosures of which is incorporated by reference herein.
FIELD OF INVENTION
[0002] The present invention relates to packaging and applicator devices for cosmetics or other care products, and more particularly but not exclusively those that are intended for applying varnish to nails.
BACKGROUND
[0003] Nail varnish flasks that are currently on the market have a variety of capacities, usually lying in the range of 7 milliliters (ml) to 14 ml. The associated applicators comprise a stem having a brush at one end and a closure cap having a threaded portion.
[0004] For flasks of relatively large capacity, for example, 12 ml or more, the height of the flask body makes it possible to use a stem that is relatively long. In contrast, for flasks of small capacity, the height of the flask body is smaller. Therefore, the stem needs to be shorter. Otherwise, the length of the bristles of the brush needs to be shorter, which would lead to a loss of flexibility and a loss in quality of application. Otherwise, the length of the neck needs to be increased, which may degrade appearance.
SUMMARY OF THE INVENTION
[0005] Exemplary embodiments of the invention provide a packaging and applicator device that has both bristles that are relatively long and a visible length of stem that is of sufficient length to make application easier.
[0006] Exemplary embodiments of the invention provide a packaging and applicator device comprising: a flask having a threaded neck; and an applicator comprising a stem, an applicator element disposed at a first end of the stem, and a closure cap supporting the stem at a second end opposite from the first end, the closure cap including a threaded portion arranged to screw onto the neck. In embodiments, the closure cap may include a ring that is releasably connected to the threaded portion and arranged to be capable of remaining secured to the neck during removal of the applicator from the flask.
[0007] Exemplary embodiments of the invention render it possible to benefit from a visible length of stem plus an applicator element that is relatively large, but without harming the appearance of the flask, for example, because of the provision of the ring at the base of the neck. Further, the ring may placed in a manner that is relatively easy and inexpensive, for example, after the flask has been filled.
[0008] Exemplary embodiments of the invention render it possible to make the ring and the threaded portion in such a manner as to give the impression, when the applicator is placed on the flask, of a closure cap that is made as a single piece, which may be desirable in terms of appearance.
[0009] As used throughout the description of the invention, the term “threaded portion” should be understood broadly as corresponding to a portion of the closure cap that includes at least one thread. Such a thread may be implemented, where appropriate, on an insert fixed within an outer cap. In such a case, the ring may be releasably connected to the insert and/or to the outer cap.
[0010] In embodiments, the ring may optionally include a thread.
[0011] In exemplary embodiments, the ring may have at least one first portion in relief that enables the ring to be snap-fastened onto at least one second portion in relief formed on the neck. The second portion in relief may comprise, for example, an annular bead. The first portion in relief may comprise, for example, an annular bead or teeth that project from a radially inner surface of the ring.
[0012] In exemplary embodiments, the ring may have at least one portion in relief arranged to retain the ring on the neck by friction.
[0013] In exemplary embodiments, the ring may have one or more splines on an inner surface thereof.
[0014] In exemplary embodiments, the ring and the threaded portion may or may not be made monolithically.
[0015] In exemplary embodiments, the ring may advantageously be made at least in part by molding a plastics material with the threaded portion. For example, the ring may be made at least in part by molding a plastics material with the outer cap when the threaded portion comprises an insert and an outer cap. In exemplary embodiments, the ring may be connected to the threaded portion by one or more breakable bridges of material.
[0016] In exemplary embodiments, the ring may be disposed on the threaded portion, for example, fitted thereto, with the threaded portion and the ring being made in different molds, for example. For example, in exemplary embodiments the ring may have a portion in relief that enables the ring to co-operate by mutually engaging with the threaded portion. The ring thus need not be connected to the threaded portion by breakable bridges of material.
[0017] In exemplary embodiments in which the ring and the threaded portion are not made monolithically, the ring and the threaded portion may be connected to each other by one of friction, snap-fastening, welding and adhering.
[0018] The ring and the threaded portion may also be connected to each other by other fastening means, either known or hereafter developed.
[0019] In exemplary embodiments, the neck may have at least one first anti-rotation portion in relief and the ring may have at least one second anti-rotation portion in relief arranged to co-operate with the first anti-rotation portion in relief. Such an arrangement may help to prevent the ring from turning relative to the neck while the closure cap is being unscrewed to separate the threaded portion from the ring.
[0020] In exemplary embodiments, the first anti-rotation portion in relief on the flask may be arranged to allow the second anti-rotation portion in relief to rotate past the first anti-rotation portion in relief on initial tightening of the closure cap onto the flask. Further, in exemplary embodiments, at least one of the first and second anti-rotation portions in relief may include a ramp which may make it easier for the first and second anti-rotation portions in relief to move past each other.
[0021] In exemplary embodiments, the ring may be prevented from turning on the neck by clamping the ring onto the neck. For example, the ring may be clamped onto the neck in exemplary embodiments in which the ring has one or more splines on an inside surface thereof.
[0022] In exemplary embodiments, at a base of the neck, the neck may have a surface that is cylindrical or may have a surface that flares toward a body of the flask. In such embodiments, the ring may be brought to bear against the surface at the base of the neck with a desired degree of clamping force.
[0023] In exemplary embodiments, the ring may be decorated.
[0024] In exemplary embodiments, the flask may be made in a variety of shapes. For example, in exemplary embodiments, the flask may have a shoulder at the base of the neck.
[0025] In exemplary embodiments, the flask may be made of glass and/or plastics material. For example, in exemplary embodiments, the flask may be made of transparent material.
[0026] In exemplary embodiments, the content of the flask may be less than or equal to about 10 ml. For example, the content of the flask may be less than or equal to about 8 ml. For example, the content may lie in a range of about 7 ml to about 5 ml.
[0027] In exemplary embodiments, a visible length of the stem and the applicator element may be greater than or equal to about 25 millimeters (mm), for example. In exemplary embodiments in which the applicator element is a brush, the visible length of a free portion of the bristles may be greater than or equal to about 12 mm, for example.
[0028] In exemplary embodiments, the flask may contain a substance for application to nails, for example, a nail varnish. In other exemplary embodiments, the flask may contain a substance for application to the face, for example, to the lips. In such embodiments, the flask may include a wiper member, for example.
[0029] In exemplary embodiments, the applicator element may be flocked. For example, the applicator element may be flocked in exemplary embodiments in which the applicator element is for application on skin or lips.
[0030] In exemplary embodiments, a length of the stem may be substantially equal to a height of the neck. For example, the length of the stem may be equal to the height of the neck to within about 30%.
[0031] In exemplary embodiments, a length of the applicator element may be substantially equal to a height of the flask body on which the neck is connected. For example, the length of the applicator element may be equal to the height of the flask body to within about 30%.
[0032] Exemplary embodiments of the invention provide a method of manufacturing a packaging and applicator device, the method comprising: screwing onto a flask having a threaded neck an applicator comprising a stem, an applicator element disposed at a first end of the stem, and a closure cap to which the stem is secured at a second end opposite from the first end, the closure cap having a threaded portion that is arranged to be screwed onto the neck and a ring that is releasably connected to the threaded portion at a base of the closure cap, the neck and the ring having shapes that co-operate to retain the ring on the neck when the threaded portion is unscrewed, for example, during use.
[0033] In exemplary embodiments, the neck and the ring may co-operate, for example, by snap-fastening or friction.
[0034] Exemplary embodiments of the invention provide a method of manufacturing a packaging and applicator device, the method comprising: screwing a threaded insert, to which the applicator element is secured, onto a flask having a threaded neck; and fitting an outer cap on the insert, the outer cap being connected releasably to a ring, the outer cap and the insert remaining secured to each other when the insert is unscrewed, the neck and the ring having shapes that co-operate to retain the ring on the neck when the insert is unscrewed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] The invention can be better understood on reading the following detailed description of non-limiting embodiments of the invention and on examining the accompanying drawings, in which:
[0036] [0036]FIG. 1 is a diagrammatic elevation view of an exemplary embodiment of a packaging and applicator device according to the invention;
[0037] [0037]FIG. 2 is a view analogous to FIG. 1, showing the exemplary device in FIG. 1 during initial unscrewing of the closure cap;
[0038] [0038]FIG. 3 is a view analogous to FIG. 1, showing the applicator fully withdrawn from the flask;
[0039] [0039]FIG. 4 shows the flask in isolation without the ring or the closure cap;
[0040] [0040]FIG. 5 is a diagrammatic axial section view of the flask shown in FIG. 3;
[0041] [0041]FIG. 6 is a diagrammatic and fragmentary axial section view of the closure cap of the exemplary device shown in FIGS. 1 to 3 ;
[0042] [0042]FIGS. 7 and 8 are diagrammatic and fragmentary axial section views showing various exemplary embodiments of the closure cap;
[0043] [0043]FIG. 9 is a diagrammatic exploded view showing another exemplary embodiment according to the invention;
[0044] [0044]FIG. 10 shows the exemplary device in FIG. 9 after the insert has been screwed onto the neck of the flask;
[0045] [0045]FIG. 11 shows the exemplary device in FIG. 10 after the outer cap and the ring have been put into place;
[0046] [0046]FIG. 12 shows the exemplary device in FIG. 11 after the applicator has been withdrawn;
[0047] [0047]FIG. 13 is a diagrammatic elevation view of another exemplary embodiment of the flask in isolation;
[0048] [0048]FIG. 14 a diagrammatic elevation view of an exemplary applicator including an applicator element that is flocked;
[0049] [0049]FIG. 15 is a diagrammatic and fragmentary axial section view of an exemplary embodiment of a flask including a wiper member;
[0050] FIGS. 16 to 18 are diagrammatic and fragmentary elevation views of various exemplary embodiments of closure caps according to the invention; and
[0051] [0051]FIG. 19 is a diagrammatic perspective view of an exemplary embodiment of an outer cap in isolation, the outer cap having an outside cross-section that is not circular.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0052] The term “care products” is used to generically refer to any substance that is used to effect one or more external body conditions, such as conditions of the skin, hair and nails. For example, such substances include, but are not limited to, treatment products, such as sunscreen, moisturizer and/or medicaments, cleansing products and cosmetic products, such as makeup products, or any other known or later developed product that may be applied to the body.
[0053] The exemplary embodiment of a packaging and applicator device 1 shown in FIGS. 1 to 3 comprises a flask 2 , made of glass or plastics material, for example, and an applicator 3 comprising a stem 4 provided at a bottom end thereof with an applicator element 5 , such as a brush, for example, and connected at a top end thereof to a closure cap 6 . In the exemplary embodiment, the cap comprises a threaded portion 7 and a bottom ring 8 .
[0054] For example, the stem 4 may be hollow with a tuft of brush bristles inserted therein. Further, a visible length l of the bristles may be about 12 mm or longer, for example.
[0055] The stem 4 may be fixed inside the closure cap 6 in a conventional manner. In embodiments, the stem 4 may be fixed inside the closure cap 6 by an insert which optionally also serves to close the flask 2 in a leaktight manner.
[0056] The threaded portion 7 allows for screwing onto the neck 10 of the flask 2 . As shown in the exemplary embodiment, the neck 10 is provided with a thread 11 .
[0057] In exemplary embodiments, the ring 8 may be initially secured to the threaded portion 7 when the applicator 3 is put into place on the flask 2 for the first time.
[0058] As shown in FIG. 6, the ring 8 may be made as a single piece together with the threaded portion 7 , for example, by molding a plastics material. The ring 8 and the threaded portion 7 may be connected together by one or more breakable bridges of material 13 . As shown in FIG. 6, the bridges of material 13 may be set back from a radially outer surface 19 of the ring 8 so as to avoid spoiling the appearance of the closure cap 6 .
[0059] In the exemplary embodiment shown, the ring 8 has at least one first portion in relief 15 , such as, for example, a bead or teeth projecting from a radially inner surface 16 . The neck 10 of the flask 2 includes at a base thereof at least one second portion in relief 18 that is arranged, for example, to enable the ring 8 to be snap-fastened onto the neck 10 at the end of the initial engagement of the closure cap 6 on the flask 2 .
[0060] In order to enable the ring 8 to be separated from the threaded portion 7 on unscrewing the closure cap 6 , at least one anti-rotation portion in relief 20 may be provided on the radially inner surface 16 of the ring 8 that co-operates with at least one complementary portion in relief 21 formed on the neck 10 . The anti-rotation portions in relief 20 and 21 may be arranged in such a manner as to enable the anti-rotation portion in relief 20 to rotate past the anti-rotation portion in relief 21 on initial engagement of the closure cap 6 . For example, the anti-rotation portions in relief 20 and 21 may include respective ramps 23 and 24 , for example, for this purpose. The ramps 23 and 24 may be sloped so as to assist the anti-rotation portion in relief 20 past the anti-rotation portion in relief 21 in the screw-tightening direction of the closure cap 6 . The anti-rotation portions in relief 20 and 21 may subsequently prevent passage in the reverse direction.
[0061] When a user unscrews the closure cap 6 for the first time, the threaded portion 7 separates from the ring 8 , which remains permanently on the neck 10 . The user may thus benefit from a visible length l′ of stem 4 that is sufficient to enable substance to be applied under desirable conditions, for example, to the fingernails.
[0062] Naturally, the invention is not limited to the embodiment described above. Various modifications may be applied to the flask and/or to the closure cap.
[0063] For example, the closure cap 6 may be made with a threaded portion 7 and a ring 8 which are connected together by one or more bridges of material 13 that extend substantially radially, as shown in FIG. 7, rather than extending substantially axially as shown in FIG. 6.
[0064] The ring 8 and the threaded portion 7 may also be connected together prior to the closure cap 6 being mounted on the flask 2 other than by breakable bridges of material.
[0065] For example, in the exemplary embodiment shown in FIG. 8, the threaded portion 7 and the ring 8 are arranged to co-operate by mutual engagement. The ring 8 may be provided, for example, with an annular rib 33 suitable for engaging in a shouldered housing 24 formed at a bottom end of the threaded portion 7 .
[0066] In the exemplary embodiment shown in FIGS. 9 to 12 , the closure cap comprises an insert 40 and an outer cap 41 in which the insert 40 may be fixed.
[0067] The insert 40 may have an inside thread 42 that enables the insert to be screwed onto the neck 10 . Further, the insert 40 may have a housing 43 that enables a top end 44 of the stem 4 to be fixed to the insert 40 .
[0068] The stem 4 may carry a collar 45 for bearing against an end edge of the neck 10 when the insert 40 is screwed home, for example, so as to close the flask 2 in a leaktight manner.
[0069] On a radially inner surface of the outer cap 41 , one or more axial splines 48 may be provided that enable the outer cap 41 to be fixed on the insert 40 , for example, by clamping. In embodiments, the outer cap 41 and the insert 40 may thus be prevented from moving relative to each other.
[0070] The ring 8 in the exemplary embodiment described above is made integrally, i.e., monolithically, with the outer cap 41 . For example, the ring 8 may be connected to the outer cap 41 by one or more bridges of material 13 situated in line with the axial splines 48 .
[0071] On an inner surface, the ring 8 may have one or more axial splines 50 situated in line with the axial splines 48 on the outer cap 41 . The axial splines 50 may serve to bear against an enlarged portion 56 at the base of the neck 10 , for example, so as to clamp sufficiently tightly to cause the ring 8 to subsequently be prevented from turning relative to the flask 2 .
[0072] After the flask 2 has been filled, the insert 40 and the stem 4 may be put into place so as to close the flask 2 , as illustrated in FIG. 10. Then the assembly formed by the outer cap 41 and the ring 8 may be fitted onto the insert 40 until the insert 40 comes to bear against the inside of the top wall of the outer cap 41 , for example, with the axial splines 48 pressing tightly against the insert 40 .
[0073] The flask 2 provided with the closure cap 6 is illustrated in FIG. 11. During use, a user unscrews the threaded portion 7 formed by the outer cap 41 and the insert 40 , while the ring 8 remains on the neck 10 of the flask by virtue of the axial splines 50 clamping onto the enlarged portion 56 , as illustrated in FIG. 12. As shown in FIG. 12, it will be understood that because the ring 8 remains on the neck 10 of the flask 2 , it is possible to increase the visible length of the stem 4 by the equivalent of the height h of the ring 8 .
[0074] In exemplary embodiments of the present invention, the neck 10 may have a surface at the base that is not circularly cylindrical, but that is frustoconical. For example, FIG. 13 shows the flask 2 , corresponding to the embodiment shown in FIGS. 1 to 5 , with a frustoconical bottom portion 32 at the base of the neck 10 that enables clamping between the ring 8 and the flask 2 to be increased, for example.
[0075] The applicator element 5 may comprise something other than a brush. For example, FIG. 14 shows a flocked applicator element 5 . Such a flocked applicator element may be suited for application on lips, for example.
[0076] The flask 2 may be made by assembling together one or more parts. For example, the flask 2 may include a wiper member 60 as shown in FIG. 15. As shown in FIG. 15, the flask 2 may comprise a body 61 having a part 62 that is fitted thereon to define the neck 10 of the flask 2 and that enables the wiper member 60 to be supported. The wiper member 60 may comprise, for example, an axially split block of foam through which the applicator element 5 can be passed. In the exemplary embodiment shown, the flask 2 may be filled with a substance P for application to the lips, for example.
[0077] The closure cap 6 may be made in a variety of shapes, as shown in FIGS. 16 to 18 . An outer section of the closure cap 6 may be circular or otherwise. For example, the outer section of the closure cap 6 may be prismatic.
[0078] For example, FIG. 19 shows an outer cap 41 of outer cross-section that is substantially square. The outer cap 41 may have an internal circularly cylindrical wall 63 for enabling an insert to be fixed thereto. Such an insert may carry the thread of the closure cap 6 and/or the stem 4 .
[0079] Throughout the description, including in the claims, the term “comprising a” should be understood as being synonymous with “comprising at least one” unless specified to the contrary.
[0080] Although the present invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention. | A device includes a flask having a threaded neck and an applicator. In embodiments, the applicator includes a stem, an applicator element disposed at a first end of the stem, and a closure cap supporting the stem at a second end of the stem opposite from the first end. The closure cap may have a threaded portion arranged to screw onto the neck. The closure cap may include a ring releasably connected to the threaded portion and arranged to be capable of remaining secured to the neck during removal of the applicator from the flask. | 0 |
FIELD OF THE INVENTION
The invention relates generally to processes for preparation of block copolymers; particularly to processes for preparation of block copolymers by a two-step polymerization and most particularly to processes for preparing diblock and triblock copolymers comprising the steps of: (a) performing radical polymerization of N-vinyl-2-pyrrolidone in the presence of a radical initiator, a chain transfer agent (optionally) and an alcoholic solvent to form hydroxy-terminated poly(N-vinyl-2-pyrrolidone) and (b) performing ionic polymerization of monomers or comonomers in the presence of a catalyst or base and a macroinitiator wherein said macroinitiator is the hydroxy-terminated poly(N-vinyl-2-pyrrolidone) formed in step (a) thereby preparing said diblock and triblock copolymers. Poly(N-vinylpyrrolidone) formed in step (a) has a molecular weight between 1,000 D and 700 kD and the diblock and triblock copolymers have a molecular weight between 2,000 D and 700 kD.
BACKGROUND OF THE INVENTION
The synthesis of well-defined polymers with controlled chain end functionalities is important for the achievement of nanotechnology. These polymers have been especially important as potential drug delivery vehicles. In the last decade, the use of various controlled polymerizations have resulted in well-defined copolymers with different designs. For example, nitroxide-mediated polymerization, dithio component-mediated reversible addition-fragmentation chain transfer and atom transfer radical polymerization (ATRP) are controlled processes, which offer control over molecular weight and molecular architecture (diblock, grafted or tapered copolymers). However, a few monomers such as vinyl acetate and N-vinyl-2-pyrrolidone (VP) do not form radicals stabilized by resonance and inductive effects, and therefore the polymerization of these monomers has not yet been performed efficiently by controlled radical polymerizations. Matyjaszewski et al. (Am. Chem. Soc. Symp. Ser. 685:258 1998 and J. Polym. Sci. Part A:Polym. Chem. 36:823-830 1998) reported the homopolymerization of VP using Me 4 Cyclam as a ligand. Chain end functionalities were difficult to obtain using the synthetic pathway described by Matyjaszewski et al.
The instant inventors are interested in functionalized and well-defined poly(N-vinyl-2-pyrrolidone) (PVP) as a replacement for poly(ethylene glycol) (PEG) in diverse drug delivery systems. Although a number of diblock or triblock copolymers can form micelles in aqueous solution, few among them are truly suitable as drug carriers due to biocompatibility issues [Alexandridis et al. Current Opinion Colloid & Interface Science 2:478-489 1997; Rapoport et al. J. Pharm. Sci. 91:157-170 2002; Kabanov et al. Adv. Drug Deliv. Rev. 54:223-233 2002; Nishiyama et al. Langmuir 15:377-383 1999; Kakizawa et al. Langmuir 18:4539-4543 2002; Katayose et al. Bioconjugate Chem. 8:702-707 1997; Yamamoto et al. J. Controlled Release 82:359-371 2002; Liggins et al. Adv. Drug Deliv. Rev. 54:191-202 2002; Kim et al. J. Controlled Release 72:191-202 2001; Yoo et al. J. Controlled Release 70:63-70 2001; Luo et al. Bioconjugate Chem. 13:1259-1265 2002; Lim Soo et al. Langmuir 18:9996-10004 2002; Gref et al. Science 263:1600-1603 1994 and Burt et al. Colloids Surf. B 16:161-171 1999]. Many studies have reported the use of polyester-block-poly(ethylene glycol) block copolymers [Yamamoto et al.; Liggins et al.; Kim et al.; Yoo et al.; Luo et al.; Lim Soo et al.; Gref et al. and Burt et al. journal citations, supra]. PEG is widely used as hydrophilic arm on the surface of nanoparticles [Kissel et al. Adv. Drug Deliv. Rev. 54:99-134 2002], liposomes [Gabizon et al. Adv. Drug Deliv. Rev. 24:337-344 1997]and polymeric micelles [Jones et al. Eur. J. Pharm. Biopharm. 48:101-111 1999; Kataoka et al. Adv. Drug Deliv. Rev. 47:113-131 2001 and Kabanov et al. Adv. Drug Deliv. Rev. 54:759-779 2002]. The PEG-based outer shell can actually prevent the nanocarrier uptake by the mononuclear phagocytic system via steric effects [Jones et al.; Kataoka et al. and Kabanov et al. journal citations; supra]. This prevention substantially improves the circulation time of polymeric micelles in the blood stream. In cancer treatment, this prolonged time generally results in a selective accumulation in a solid tumor due to the enhanced permeability and retention effect of the vascular endothelia at the tumor site [Yokoyama et al. Cancer Res. 50:1693-1700 1990; Yokoyama et al. Cancer Res. 51:3229-3236 1991; Kwon et al. J. Controlled Release 29:17-23 1994; Yokoyama et al. J. Controlled Release 50:79-92 1998 and Yamamoto et al. J. Controlled Release 77:27-38 2001]. However, since aggregation of nanoparticles with PEG as corona occurs during lyophilization, it features some limitations. Thus, PEG is not ideally suited for efficient use in drug delivery systems.
Functionalized and well-defined PVP is an ideal component for replacement of PEG in drug delivery systems. PVP has been proven to be biocompatible [Haaf et al. Polymer J. 17:143-152 1985] and has been extensively used in pharmaceutical industry. Particularly, PVP can be used as cryoprotectant [Doebbler et al. Cryobiology 3:2-11 1966] and lyoprotectant [Deluca et al. J. Parent. Sci. Technol. 42:190-199 1988]. Hence, replacing PEG with PVP in drug delivery systems might help to overcome some freeze drying problems.
Torchilin et al. [J. Microencapsulation 15:1-19 1998] pioneered the study of PVP as hydrophilic corona of liposomes. The design of polymeric micelles with PVP outer shell have presented promising features for pharmaceutical uses. Thus, Benahmed et al. [Pharm. Res. 18:323-328 2001] reported the preparation of PVP-based micelles consisting of degradable diblock copolymers. In the work of Benahmed et al., PVP synthesis using 2-isopropoxyethanol as chain transfer agent was inspired from by previous work of Ranucci et al. [Macromol. Chem. Phys. 196:763-774 1995 and Macromol. Chem. Phys. 201:1219-12252000]. However, this synthetic procedure produced a lack of control over molecular weight, and did not quantitatively provide hydroxyl-terminated PVP, which is essential for polymerizing DL-lactide [Benahmed et al. Pharm Res. 18:323-3282001]. Moreover, the removal of 2-isopropoxy-ethanol from the polymer turned out to be difficult because of its high boiling point (42-44° C. at 13 mmHg) and its binding to PVP via hydrogen bonding [Haaf et al. Polymer J. 17:143-1521985]. Alcohol entrapment into polymer might cause problems for subsequent reactions which require anhydrous and aprotic conditions such as the synthesis of poly(D,L-lactide). Sanner et al. [Proceeding of the International Symposium on Povidone, University of Kentucky: Lexington, Ky., 1983, pp. 20] reported the synthesis of hydroxyl-terminated PVP oligomers via free radical polymerization in isopropyl alcohol (IPA), using cumene hydroperoxide as an initiator. 1 H-NMR spectra have shown that there were 1.3 end groups of 2-hydroxyisopropyl per chain. It is suggested that significant termination by bimolecular combination occurred, between either a primary solvent radical and the propagating chains [Liu et al. Macromolecules 35:1200-1207 2002].
U.S. Pat. No. 6,338,859 (Leroux et al.) discloses a class of poly(N-vinyl-2-pyrrolidone)-block-polyester copolymers. Such PVP block copolymers represent new biocompatible and degradable polymeric micellar systems which do not contain PEG, but which exhibit suitable properties as drug carriers. PVP shows remarkable diversity of interactions towards non-ionic and ionic cosolutes. Prior to the disclosure by Leroux et al., only a random graft copolymer, poly(N-vinyl-2-pyrrolidone)-graft-poly (L-lactide) had been described in the literature [Eguiburu et al. Polymer 37:3615-3622 1996].
In the synthesis of the amphiphilic diblock copolymer disclosed by Leroux et al. hydroxy-terminated PVP was prepared by radical polymerization using 2-isopropoxyethanol as a chain transfer agent. The block copolymer was obtained by anionic ring opening polymerization. Although the strategy of Leroux et al. works very well for the preparation of the desired amphiphilic diblock copolymers in the laboratory, several problems remain to be solved in order to achieve a scalable process. The use of crown ether and the need of dialysis and ultra-centrifugation for the copolymer purification are not desirable on an industrial scale. Furthermore, in the process disclosed by Leroux et al., the degree of functionalization of hydroxyl-terminated PVP was not assessed.
What is lacking in the art is a process for preparing hydroxyl-terminated PVP, and using such functionalized PVP to prepare amphiphilic PVP-block-polyester block copolymers as well as other diblock or triblock copolymers consisting of PVP as one block; wherein the molecular weight, polydispersity index and functionality of the PVP can be controlled and wherein the process can be carried out on an industrial scale.
SUMMARY OF THE INVENTION
The instant invention provides a two-step polymerization process for preparing hydroxyl-terminated PVP and amphiphilic PVP-block-polyester as well as other diblock or triblock block copolymers consisting of PVP as one block. The process enables control of the molecular weight, polydispersity and functionality of the PVP. The diblock and triblock copolymers of the instant invention can be synthesized on an industrial scale for utilization in drug carrier systems.
The process of the instant invention comprises a two-step polymerization. The first step comprises free radical polymerization of VP in the presence of a radical initiator and an alcoholic solvent resulting in the synthesis of a low molecular weight PVP with a terminal hydroxyl group (PVP-OH). This step can be carried out with or without a chain transfer agent. The newly synthesized PVP-OH is purified by re-precipitation. The molecular weight of the PVP-OH can be effectively tuned and controlled by adjusting the molar ratios of radical initiator, chain transfer agent and alcohol to VP. With the use of higher concentrations, recombination of polymer chains is favored so that PVP with a hydroxyl group at both ends of each polymer chain (HO-PVP-OH) can be selectively obtained. Illustrative, albeit non-limiting examples of radical initiators are 2,2′-azobis(2-methyl-N-(2-hydroxyethyl)-propionamide (AMPAHE), 2,2′-azobis(2-methyl-N-[2-(1-hydroxybutyl)]-propionamide and 1,1′azobis(cyclohexane-carbonitrile). AMPAHE is a particularly preferred radical initiator, the use of which is illustrated in the examples herein. Illustrative, albeit non-limiting examples of alcoholic solvents are methanol, ethanol, isopropyl alcohol, n-propanol, n-butanol, tert-butanol, 1-pentanol and 2-pentanol. Isopropyl alcohol (IPA) is a particularly preferred alcoholic solvent, the use of which is illustrated in the examples herein. Illustrative, albeit non-limiting examples of chain transfer agents are 2-mercaptoethanol, 3-mercapto-1-propanol, 3-mercapto-2-propanol, 4-mercapto-1-butanol, 3-mercapto-2-butanol and 6-mercapto-1-hexanol. A particularly preferred chain transfer agent is 2-mercaptoethanol (MCE), the use of which is illustrated in the examples herein.
The second step of the process comprises anionic polymerization of a monomer or comonomers using the dry hydroxyl-terminated PVP, synthesized in the first step, as a macroinitiator resulting in the formation of amphiphilic PVP-block-polyester diblock or triblock copolymers or other diblock and triblock copolymers consisting of PVP as one block. The second step is carried out using a catalyst or base in an inert aprotic solvent without the use of crown ether or other complexation agents. The newly formed block copolymers are isolated by precipitation and purified by dissolution and re-precipitation. No dialysis is necessary for purification. Charcoal treatment can be used to remove any color from the newly formed block copolymers. The molecular weight of the block copolymer and the percentage content of polyester can be controlled by adjusting the ratio of the macroinitiator and the monomer(s). Illustrative, albeit non-limiting examples of catalysts are aluminium and tin alkoxides. Illustrative, albeit non-limiting examples of bases are potassium and sodium hydride. Illustrative, albeit non-limiting examples of inert aprotic solvents are tetrahydrofuran, toluene, diethyl ether and tert-buytl methyl ether. Tetrahydrofuran is a preferred inert aprotic solvent, the use of which is illustrated in the examples herein.
Accordingly, it is an objective of the instant invention to provide a two-step polymerization process for preparing PVP, amphiphilic PVP-block-polyester copolymers and other diblock or triblock copolymers consisting of PVP as one block.
It is a further objective of the instant invention to provide a two-step polymerization process for preparing diblock and triblock copolymers wherein said process enables control of the molecular weight, polydispersity and functionality of the components of each of the polymerizations.
It is yet another objective of the instant invention to provide a two-step polymerization process for preparing diblock and triblock copolymers wherein said process can be carried out on an industrial scale.
It is a still further objective of the invention to provide (PVP)-block-polyester copolymers for use as drug carriers.
Other objects and advantages of this invention will become apparent from the following description taken in conjunction with the accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention. The drawings constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof.
Definitions
The following list defines terms, phrases and abbreviations used throughout the instant specification. Although the terms, phrases and abbreviations are listed in the singular tense the definitions are intended to encompass all grammatical forms.
As used herein, the abbreviation “PEG” refers to poly(ethylene glycol).
As used herein, the abbreviation “PM” refers to polymeric micelles.
As used herein, the abbreviation “VP” refers to N-vinyl-2-pyrrolidone.
As used herein, the abbreviation “PVP” refers to poly(N-vinyl-2-pyrrolidone).
As used herein, the abbreviation “PVP-OH” refers to PVP with a hydroxyl group at one terminus of each polymer chain.
As used herein, the abbreviation “HO-PVP-OH” refers to PVP with hydroxyl groups at both termini of each polymer chain.
As used herein, the abbreviation “PDLLA” refers to poly(D,L-lactide).
As used herein, the abbreviation “PVP-b-PDLLA” refers to poly(N-vinylpyrrolidone)-block-poly(D,L-lactide).
As used herein, the abbreviation “MALDI-TOF” refers to matrix-assisted laser/desorption/ionization time-of-flight mass spectrometry.
As used herein, the abbreviation “MW” refers to molecular weight.
As used herein, the abbreviation “M W ” refers to weight average molecular weight.
As used herein, the abbreviation “M n ” refers to number-average molecular weight.
As used herein, the abbreviation “NMR” refers to nuclear magnetic resonance.
As used herein, the abbreviation “EA” refers to elementary analysis.
As used herein, the abbreviation “SEC-LS” refers to size-exclusion chromatography coupled to light-scattering detection.
As used herein, the abbreviation “IPA” refers to isopropanol or isopropyl alcohol.
As used herein, the abbreviation “AMPAHE” refers to 2,2′-azobis(2-methyl-N-(2-hydroxyethyl)-propionamide.
As used herein, the abbreviation “MCE” refers to 2-mercaptoethanol.
As used herein, the abbreviation “TBME” refers to tert-butyl methyl ether.
As used herein, the abbreviation “MIBK” refers to 4-methyl-2-pentanone.
As used herein, the abbreviation “THF” refers to tetrahydrofuran.
As used herein, the abbreviation “NaH” refers to sodium hydride.
As used herein, the abbreviation “LA” refers to D,L-lactide.
As used herein, the abbreviation “ATRP” refers to atom transfer radical polymerization.
As used herein, the abbreviation “DMF” refers to N,N-dimethylformamide.
As used herein, the abbreviation “TBA” refers to tert-butyl alcohol.
As used herein, the abbreviation “CAC” refers to critical association concentration.
As used herein, the abbreviation “DLS” refers to dynamic light scattering.
As used herein, the abbreviation “TGA” refers to thermogravimetry analysis.
As used herein, the abbreviation “CTA” refers to chain transfer agents.
As used herein, the abbreviation “PI” refers to polydispersity index.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 shows NMR data from example 1 ( 1 H NMR (CDCl 3 ), δ (ppm). The product of step 1 is dried until the solvent peak disappears in NMR.
FIG. 2 shows NMR data from example 2 ( 1 H NMR (CDCl 3 ), δ (ppm). The product of step 2 is dried until the solvent peak disappears in NMR.
FIG. 3 illustrates the synthesis of PVP-OH homopolymer (first polymerization) and PVP-b-PDLLA diblock copolymer (second polymerization).
FIG. 4 shows a spectrum resulting from MALDI-TOF spectrometry (example 8). MALDI-TOF analysis is useful for evaluation of the hydroxyl groups of PVP-OH.
FIGS. 5A-B show data evidencing the influence of the ratios of MCE ( FIG. 5A ) and IPA ( FIG. 5B ) to .VP on the M n of PVP-OH.
FIG. 6 shows a 1 H NMR spectrum of PVP-OH-2500 in CDCl 3 (example 6).
FIGS. 7A-B show 1 H NMR spectra of PVP-b-PDLLA (Diblock-47) in CDCl 3 ( FIG. 7A ) and in D 2 O ( FIG. 7B ).
FIG. 8 shows a thermogravimetric profile of PVP-b-PDLLA diblock copolymer (Diblock-47).
FIG. 9 shows the size distribution of micelles composed of PVP-b-PDLLA (Diblock-47) in water measured by DLS.
FIG. 10 shows data for determination of CAC of PVP-b-PDLLA (Diblock-47) in water at 25° C.
DETAILED DESCRIPTION OF THE INVENTION
The synthesis of the diblock and triblock copolymers is a two-step polymerization process.
The first step is a free radical polymerization of VP, carried out in an alcoholic solvent such as methanol, ethanol, isopropanol, n-propanol, n-butanol, 2-butanol, tert-butanol, 1-pentanol and 2-pentanol. Ideally, the boiling point of the solvent is in the vicinity of the cracking temperature of the radical initiator. Isopropanol (IPA) is a preferred solvent. The presence of a radical initiator is required. The radical initiator is selected from the group of azo derivatives comprising 2,2′-azobis(2-methyl-N-(2-hydroxyethyl)-propionamide) (AMPAHE), 2,2′-azobis{2-methyl-N-[2-(1-Hydroxybutyl)]propionamide and 1,1′-azobis(cyclohexane-carbonitrile). The preferred initiators are those having hydroxyl end groups, with 2,2′-azobis(2-methyl-N-(2-hydroxyethyl)-propionamide) (AMPAHE) being the most preferred. Thiol derivatives such as 2-mercaptoethanol, 3-mercapto-1-propanol, 3-mercapto-2-propanol, 4-mercapto-1-butanol, 3-mercapto-2-butanol and 6-mercapto-1-hexanol can be used as chain transfer agents. The preferred chain transfer agent is 2-mercaptoethanol (MCE). The molecular weight can be controlled by adjusting the molar ratios of MCE, AMPAHE and IPA to VP. The resulting first block homopolymer PVP can be evaluated using techniques such as MALDI-TOF, SEC-LS, EA and NMR. PVP-OH is isolated by precipitation of its solution to an inert organic solvent with poor solubility for the polymer. The solvent or combination of solvents for dissolution is selected from the group comprising methanol, ethanol, IPA, acetone, 2-butanone, 4-methyl-2-pentanone, dichloromethane and tetrahydrofuran. The preferred solvents for dissolution are isopropanol and 4-methyl-2-pentanone, the use of which are illustrated in the examples herein. The inert organic solvent for precipitation is selected from the group comprising diethyl ether, tert-butyl methyl ether, hexane derivatives, heptane derivatives, ethyl acetate, isopropyl acetate, toluene and xylene derivatives. The preferred solvent for precipitation is tert-butyl methyl ether, the use of which is illustrated in the examples herein.
For the preparation of PVP-OH (first step of the process), once all reagents and solvent are charged, the reaction mixture is degassed prior to heating. The reaction temperature ranges from 60-140° C. depending on the initiator and solvent chosen. In a preferred embodiment of the invention, a combination of IPA as solvent, AMPAHE as initiator and MCE as chain transfer agent is used and the reaction is carried out at reflux. The reaction time ranges from 16 hours to 72 hours depending on the solvent, initiator and chain transfer agent. In the above preferred combination, a typical reaction time is between 30-48 hours.
It is important to ensure the dryness of the PVP-OH in order to succeed with the anionic ring opening polymerization in the next step. The drying of the polymer is performed using a vacuum oven with the temperature ramping towards 110° C. Alternatively, further drying can be optionally performed using azeotropic distillation with an inert solvent such as toluene, xylene derivatives or heptane derivatives prior to the second polymerization.
The second step is based on an anionic polymerization of cyclic ester, other cyclic lactone, methacrylate, or methacrylamide. This polymerization can be anionic via a macroinitiator or it can be catalyzed by aluminum or tin alkoxides. The macroinitiator is a metal PVP-hydroxylate obtained from the deprotonation of the terminal hydroxyl group with a metal hydride reagent such as sodium hydride or potassium hydride. The resulting second block is poly(ester) wherein the repeating unit is a lactide, ε-caprolactone, γ-caprolactone or other cyclic ester. The resulting second block also can be poly(amino acid), polymethacrylate, polymethacrylamide or their copolymers. The blocks of homopolymers are linked chemically by a covalent bond. The chemical linker between block homopolymers is a hydroxy derivative emerging from the radical initiator or chain transfer agent or an alcoholic solvent. An inert anhydrous aprotic solvent or combination of solvents such as tetrahydrofuran, toluene, diethyl ether, tert-butyl methyl ether can be used for the reaction, with tetrahydrofuran being preferred. The reaction temperature ranges from room temperature to about 70° C. with preferred temperature being 20-25° C. Upon completion of the reaction as evidenced by 1 H NMR (solvent peak disappears), the reaction mixture is filtered and the block copolymer is isolated from the filtrate by precipitation into an inert organic solvent which has poor solubility for the polymer. Similar solvent systems as for the precipitation of PVP-OH are used, with tert-butyl methyl ether being the most preferred solvent. Optionally, any color of PVP block copolymers can be removed by charcoal treatment and a white to off-white powder of the product is obtained.
The invention is further illustrated by the following non-limiting examples.
EXAMPLE 1
Preparation of poly(N-vinyl-2-pyrrolidone) with a Hydroxyl-Bearing Chain End (PVP-OH)
VP (200 g, 1.8 mol), AMPAHE (5.2 g, 0.018 mol) and MCE (5.0 mL, 0.072 mol) were dissolved in 3000 mL of IPA. The solution was degassed by nitrogen purge for 1 hour. The radical polymerization was carried out at reflux (about 89° C.) with stirring under a dry nitrogen atmosphere for 44 hours. Then, after cooling to room temperature, most IPA was removed under reduced pressure and 400 mL of MIBK were added. Afterwards, the polymer was slowly precipitated into 5000 mL of TBME. The suspension was filtered. The filter cake was washed twice with 200 mL of TBME. The white powder thus obtained was purified by solubilization in 400 mL of MIBK and 100 mL of IPA and re-precipitation from 5000 mL of TBME. Finally, the product was dried under vacuum (starting at room temperature then at 110° C., 1 torr) until disappearance of the solvent peak by NMR ( FIG. 1 ). The PVP-OH was obtained as a white powder: 122 g. M n : 2060, M w : 2600, M w /M n : 1.3.
The instant inventors performed similar preparations of PVP-OH varying the different parameters such as the ratio of solvent/VP and the molar percentage of AMPAHE and MCE. Table 1 demonstrates that the molecular weight (M w ) and number-average molecular weight (M n ) of PVP-OH can be tuned effectively. The results showed also that the polydispersity index (M w /M n ) is generally lower when MCE is present. Lower M w and M n are obtained when the solvent/VP ratio is higher.
TABLE 1
Characterization of PVP-OH prepared under various conditions
AMPAHE
MCE
IPA/VP
M n
M w
Entry
VP (g)
(% mol)
(% mol)
(volume ratio)
(gmol −1 )
(gmol −1 )
M w /M n
1
5
1.0
¾
10
10290
21300
2.1
2
5
1.0
¾
15
6760
15820
2.3
3
5
1.0
¾
20
6300
12460
2.0
4
20
0.5
1.0
10
5100
11600
2.3
5
50
1.0
2.0
12
4000
6220
1.6
6
50
1.0
2.0
16
2510
3470
1.4
7
15
1.0
4.0
12
3230
4520
1.4
8
200
1.0
4.0
15
2060
2600
1.3
9
50
1.0
4.0
16
2170
3190
1.5
EXAMPLE 2
Preparation of Diblock Copolymer poly(N-vinyl-2-pyrrolidone)-block-poly(DL-lactide) (PVP-PDLLA)
PVP-OH (100 g, 48.5 mmol, Mn=2060) was dissolved in 600 mL of anhydrous THF and sodium hydride 60 wt. % in mineral oil (3.0 g, 75 mmol) was added. The mixture was stirred for 30 minutes at room temperature and LA (125 g, 125% w/w) was then added. The anionic polymerization was carried out at room temperature with stirring under dry nitrogen atmosphere for 26 hours. Excess of sodium hydride was removed by filtration. The volume of filtrate was adjusted to 900 mL by addition of THF. Afterwards, the polymer solution was slowly precipitated into 4500 mL of TBME. The suspension was filtered. The filter cake was washed twice with 100 mL of TBME. The slightly yellow powder so obtained was purified by solubilization in 1215 mL of THF and 40.5 g of charcoal was added. The black suspension was stirred for 16 hours at room temperature then filtered over celite. The polymer was precipitated in 6000 mL of TBME. The suspension was filtered. The filter cake was washed twice with 100 mL of TBME and finally dried under vacuum until disappearance of the solvent peak by NMR ( FIG. 2 ). The PVP-PDDLA was obtained as a white to off-white powder: 62 g. M n : 3140, M w : 3445, M w /M n : 1.1.
Empirical equations (Equation 1) and (Equation 2) were created to evaluate the molar percent PDLLA content by proton NMR and by Elemental Analysis, respectively.
Equation 1: Determination of PDLLA (% mol) Content by Proton NMR
PLA ( % mol ) = I 5.2 ppm [ ( I 4.5 - 0.8 ppm ) - 3 × I 5.2 ppm 9 H ] + I 5.2 ppm × 100 ( 1 )
Where I 5.2 ppm represents the integration of the signal at 5.2 ppm which corresponds to the tertiary proton on C-10. I 4.5-0.8 PPM represents the integration of the signals of the protons of the PVP-OH. The contribution of the linker is omitted.
Equation 2: Determination of PDLLA (% mol) Content by Elemental Analysis (EA)
PLA ( % mol ) = 7 C - 36 N 7 C - 18 N × 100 ( 2 )
The block compositions of PVP and PDLLA correspond to the repeating unit of C 6 H 9 NO and C 3 H 4 O 2 , respectively. The PDLLA content (% mol) can be determined using equation (2) and based on the content of (c) and (N) atoms determined by EA.
Table 2 demonstrates the reproducibility of the molar percent PDLLA contents as well as the narrow polydispersity using the process.
TABLE 2 Preparation of PVP-PDLLA diblock copolymers according to Example 2. M n PVP-OH M n M w M w / PDLLA PDLLA used SEC SEC M n contents A contents B Entry (gmol −1 ) (gmol −1 ) (gmol −1 ) SEC (% mol) (% mol) 1 2060 3140 3445 1.1 38 48 2 1850 3350 3690 1.1 38 48 3 2220 3680 4050 1.1 37 48 A from equation 1, 1 H-NMR B from equation 2, EA ratio
Table 3 demonstrates that the molar contents of PDLLA in the diblock copolymer are influenced by the weight ration of Lactide/PVP-OH charged to the reaction. A desired PDLLA % content can be predictably obtained.
TABLE 3
Characterization of PVP-PDLLA diblock copolymers.
Lactide
M n PVP-OH
M n
M w
PDLLA
PDLLA
used
used
SEC
SEC
M w /M n
contents A
contents B
Entry
(% w/w)
(gmol −1 )
(gmol −1 )
(gmol −1 )
SEC
(% mol)
(% mol)
1
90
2180
3145
4040
1.3
27
38
2
110
2165
3380
3720
1.1
35
42
3
125
2220
3680
4050
1.1
37
48
A from equation 1, 1 H-NMR
B from equation 2, EA ratio
EXAMPLE 3
Synthesis of poly(N-vinylpyrrolidone) with a Hydroxyl-Bearing Chain End (PVP-OH)
As shown in FIG. 3 , PVP-OH was synthesized by free radical polymerization of VP. VP (30 g, 270 mmol), AMPAHE (0.7783 g, 2.7 mmol) and MCE (0.844 g, 10.8 mmol) were dissolved in 540 mL of IPA. The solution was degassed with argon for 15 minutes. The polymerization was carried out at 85° C. for 24 hours. Then, most of IPA was removed under reduced pressure. Afterwards, the polymer was precipitated in about 300 mL of diethyl ether. The polymer was dissolved in 60 mL of methylene chloride, and precipitated again in 300 mL of diethyl ether. Finally, the product (white powder) was transferred into a Whatman cellulose extraction thimble, and purified by diethyl ether Soxhlet extraction for 24 hours. The polymer was dried at 80° C. under vacuum overnight.
EXAMPLE 4
Synthesis of Diblock Copolymer poly(N-vinylpyrrolidone)-block-poly(D,L-lactide)
As illustrated in FIG. 3 , PVP-b-PDLLA was synthesized by anionic polymerization of LA using PVP-OH as macroinitiator. PVP-OH M n : 2500 (15 g, 5.77 mmol) was dissolved in 250 mL toluene. Using a Dean-Stark trap, all products were dried with toluene as azeotropic solvent. Toluene was then removed by distillation under reduced pressure. The polymer was dried under vacuum over P 2 O 5 at 150° C. for 4 hours. After cooling down to room temperature, potassium hydride (KH, 0.346 mg, 8.65 mmol) in mineral oil was added into the flask under argon atmosphere. The flask was placed under vacuum again for 30 minutes. A volume of 75 mL freshly distilled and anhydrous THF was added to dissolve the mixture. After the polymer was dissolved, the solution was stirred for 10 minutes. LA (30 g, 20.8 mmol) and 18-crown-6 (2.29 mg, 8.65 mmol), both previously dried under vacuum at 80° C. for 4 hours, were placed in a flask and then, dissolved with a volume of 150 mL of anhydrous THF. The solution was transferred into the alcoholate solution under argon atmosphere, and stirred. The polymerization was carried out at 60° C. for 18 hours. PVP-b-PDLLA was precipitated in 1.2 L of cold diethyl ether. The polymer was collected and dried under vacuum at room temperature. PVP-b-PDLLA (20 g) was dissolved in 100 mL of DMF. 100 mL of deionized water was added to the polymer solution for micellization. The micelle solution was placed in dialysis bag (Spectrum, MW cutoff: 3500) and dialyzed against water (8 L) at 4° C. for 24 hours. Water was changed at least 4 times over that period. The aqueous solution was centrifuged at 11600 g at 4° C. for 30 minutes, and then filtered through a 0.2-hum filter. The filtered solution was collected and freeze-dried during 48 hours. The diblock copolymer was stored at −80° C. to avoid degradation.
EXAMPLE 5
Size-Exclusion Chromatography
The SEC analysis was carried out on a Breeze Waters system using refractometer Waters 2410 (Milford, Mass.) and light-scattering (LS) detector Precision Detectors PD2000 (Bellingham, Mass.). LS data were collected at 15 and 90°. SEC was performed in DMF containing 10 MM LiBr. 200 μL of solution (about 3% w/v) was injected through a series of 3 columns Styragel® Waters HT2, HT3 and HT4 at a flow rate of 1.0 mL/min, in order to separate MW ranging from 10 2 to 10 6 . The temperature of columns (separation) was maintained at 40° C., while the temperature of refractometer/LS detectors was set at 35° C. The instrument was calibrated with monodisperse polystyrene standards.
EXAMPLE 6
Nuclear Magnetic Resonance
1 H- and 13 C-NMR spectra were recorded on Varian 300 and Bruker AMX 600 spectrometers (Milton, Ontario) in CDCl 3 at 25° C. The PDLLA content (% mol) was determined using equation 1 (as noted in Example 2). Where I 5.2 ppm represents to signal intensity at 5.2 ppm, and corresponds to the tertiary proton (α-position of carbonyl group). This signal was normalized to 1. 1 H-NMR was also performed in deuteriated water (D 2 O) at 25° C. to evidence the presence of self-assembled micelle.
EXAMPLE 7
Elementary Analysis
EA was carried out in an oxidative atmosphere at 1021° C. Using a thermal conductivity probe, the amount of nitrogen oxide, carbonic acid, sulfur oxide (NO 2 , SO 2 and CO 2 ) and water were quantified and provided the amount of nitrogen (N), carbon (C), hydrogen (H) and sulfur (S) atoms into the sample. The block compositions of PVP and PDLLA correspond to the repeating unit of C 6 H 9 NO and C 3 H 4 O 2 , respectively. The PDLLA content (% mol) was determined using equation 2 (as noted in Example 2) and based on the content of (C) and (N) atoms.
EXAMPLE 8
MALDI-TOF Spectrometry for Analysis of PVP
MALDI-TOF mass spectra were obtained with a Micromass TofSpec-2E mass spectrometer (Manchester, UK). The instrument was operated in positive ion reflectron mode with an accelerating potential of +20 kV. Spectra were acquired by averaging at least 100 laser shots. Dithranol was used as a matrix and chloroform as a solvent. Sodium iodide was dissolved in methanol and used as the ionizing agent. Samples were prepared by mixing 20 μL of polymer solution (6-8 mg/mL) with 20 μL of matrix solution (10 mg/mL) and 10 μL of a solution of ionizing agent (2 mg/mL). Then 1 mL of these mixtures was deposited on a target plate and the solvent was removed in a stream of nitrogen. An external multipoint calibration was performed by using bradykinin (1060.2 g/mol), angiotensin (1265.5 g/mol), substance P (1347.6 g/mol), renin substrate tetradecapeptide (1759.0 g/mol), and insulin (5733.5 g/mol) as standards.
EXAMPLE 9
Viscosity-Average Molecular Weight (M v ) Determination of PVP
The limiting viscosity number “K-value” (or Fikentscher K-value) of homopolymer PVP-OH was determined in accordance with BASF protocol (US Pharmacopoeia) using Ubbelohde viscometer Type 1a. With the K-value, M v , is directly obtained from the following equation: M v =22.22(K+0.075K 2 ) 1.69 .
EXAMPLE 10
Critical Association Concentration (CAC)
CAC was measured by the steady-state pyrene fluorescence method (Benahmed et al. Pharm. Res. 18:323-328 2001). The procedure is described briefly as follows. Several polymeric solutions in water containing 10 −7 M of pyrene were prepared and stirred overnight in the dark at 4° C. Steady-state fluorescent spectra were measured (λ ex ,=390 nm) after 5 minutes under stirring at 20° C. using a Series 2 Aminco Bowman fluorimeter (Spectronic Instruments Inc., Rochester, N.Y.). Experiments were run in duplicate.
EXAMPLE 11
Dynamic Light-Scattering (DLS)
DLS was used for the determination of particle size in water. For this analysis, a series of aqueous solutions of PVP-b-PDLLA with concentrations of 0.5, 1 and 2 mg/mL was prepared by dissolving the polymer directly in water. The solutions were analyzed with a Malvern instrument Autosizer 4700 (Mississauga, Ontario). Each measurement was carried out in triplicata at 25° C. at an angle of 90° C. The size distribution of particles and the intensity mean size were recorded.
EXAMPLE 12
Thermogravimetry Analysis (TGA)
TGA measurements were collected on a TA Instrument Hi-Res TGA 2950 Thermogravimetric Analyser (New Castle, Del.).
About 1 mg of polymer was used for the experiments. Temperature ramp was 20° C./minutes between room temperature and 700° C. The residual amount of water was quantified after freeze-drying. PDLLA and PVP contents (% w/w) in diblock copolymer were also analyzed.
Experimental Results from Examples
Mercapto compounds are good chain transfer agents capable of functionalizing chain ends and controlling indirectly polymer molecular weight (Ranucci et al. Macromol. Chem. Phys. 196:763-774 1995; Ranucci et al. Macromol. Chem. Phys. 201:1219-1225 2000; Sanner et al. Proceedings of the International Symposium on Povidone; University of Kentucky: Lexington, Ky., page 20, 1983). A Hydroxyl group can be introduced at the end of polymer chains by using MCE as CTA in free radical polymerization of vinyl monomers. However, it was reported that when VP was radically polymerized in the presence of mercapto derivatives, only a small fraction of functionalized short oligomers was obtained. Moreover, a large amount of high MW polymers without terminal functionality was found in the product. This was due to the high transfer constant of thiol to VP (Ranucci et al. Macromol. Chem. Phys. 196:763-774 1995; Ranucci et al. Macromol. Chem. Phys. 201:1219-1225 2000). In the free radical polymerization of VP, radicals can transfer to solvent and possibly to a monomer. Hence, functionalized PVP had been synthesized using particular solvents (i.e. isopropoxyethanol). However, the functionality of PVP was not under control quantitatively (Ranucci et al. Macromol. Chem. Phys. 196:763-774 1995; Ranucci et al. Macromol. Chem. Phys. 201:1219-1225 2000). In order to get quantitative hydroxyl-terminal PVP homopolymers and also to control their molecular weight profile, IPA, MCE and a hydroxyl-bearing azo initiator (AMPAHE) have been all combined in the instant invention for the radical polymerization of VP (see FIG. 3 ).
As shown in FIG. 4 , MALDI-TOF spectrometry showed that the majority of PVP chains (>95%) bore a hydroxyl group at one chain end of PVP. FIG. 4 shows a MALDI-TOF spectrum of PVP-OH-2500. Most chains featured a 2-hydroxyisopropyl group at the end, meaning that the solvent was the main specie initiating polymer growth. Using diluted conditions of polymerization, MALDI-TOF data suggests that no significant termination by bimolecular combination occurred during the reaction, because the mass of chain end was only that of IPA plus the sodium ion (59 IPA +23 NA +=82, at n equals 0 in the linear equation). Two other distributions were also observed, which were attributed to PVP bearing MCE and VP as chain end, respectively. These distributions were only significant at low values of m/z (<1000 g mol −1 ) and represented less than 5% of the spectrum, related to MCE- and VP-terminated chains. Since MCE is more efficient as a chain transfer agent than IPA, all the MCE were consumed early in the reaction. Previous syntheses of PVP in THF (instead of IPA) using MCE have shown that radicals may also transfer directly to monomers (Ranucci et al. Macromol. Chem. Phys. 196:763-774 1995; Ranucci et al. Macromol. Chem. Phys. 201:1219-1225 2000). In consequence, by combining MCE and IPA as CTA, the synthesis of low MW PVP could be achieved with the quantitative insertion of hydroxyl group on one chain end.
The molecular weights of PVP-OH were determined by SEC and viscometry (Table 4). Polydispersity indexes (PI) of about 1.5 indicated that radial transfers prevailed over bimolecular combination, being consistent with MALDI-TOF data. Results from SEC and viscometry were in good agreement. M v might be slightly overestimated because the universal equation established by BASF referred to a wide range of PVP MW (10 3 to 10 6 ). Mark-Houwink constants (K and α) of low MW polymers differ from those having very high MW, which may explain this overestimation. Analysis of PVP-OH by EA revealed that the weight ratios of N/C atoms in all PVP-OH were similar to the theoretical number (0.194).
TABLE 4
Characterization of hydroxyl-terminated PVP homopolymers.
M n
M w
M v
SEC
SEC
M w /M n
Viscometer
N/C
Polymers
(g mol −1 )
(g mol −1 )
SEC
(g mol −1 )
EA
PVP-OH-2300
2300
3600
1.56
5400
0.192
PVP-OH-2500
2500
4000
1.60
5500
0.190
PVP-OH-4000
4000
7400
1.85
9000
0.193
PVP-OH-6100
6100
9600
1.57
11100
0.197
Molecular weight profile of PVP-OH was controlled by changing ratios of both MCE (the CTA) and IPA, to VP monomer. As expected, the molecular weights of PVP-OH decreased when either CTA/VP or IPA/VP ratios increased ( FIGS. 5A-B ). In FIG. 5A the ratios of IPA/VP are fixed at (▪) 18 mL/g and (●) 15 mL/g. In FIG. 5B the ratio of MCE/VP is fixed at (▴) 2.5%.
The 1 H NMR spectrum of PVP-OH-2500 in CDCl 3 is shown in FIG. 6 . The chemical shifts of the methylene groups of MCE are 2.7 and 3.8 ppm. When MCE was introduced at the end of the PVP-OH chains by forming S—C bond instead of S—H bond, the peaks of one methylene group appear at 2.7 and 2.75 ppm instead of 2.7 ppm, and the signal located around 3.8 ppm is overlapped with the peaks of PVP-OH in the spectrum. Signals between 1.1 and 1.3 ppm are assigned to the methyl protons of the 2-hydroxyisopropyl group (IPA fragment). These results suggest that PVP radicals transferred to both MCE and IPA, and this is in agreement with the results obtained from MALDI-TOF spectrometry.
Potassium hydroxylate derivatives are widely used for anionic ring-opening polymerization of LA (Nagasaki et al. Macromolecules 31:1473-1479 1998; Iijima et al. Macromolecules 32:1140-1146 1999; Yasugi et al. Macromolecules 32:8024-8032 1999). In the instant invention, the reaction between the OH group at the chain end of PVP-OH and potassium hydride produced potassium PVP-hydroxylate as macroinitiator for the polymerization of LA. Water and alcohol molecules in the reaction system may initiate the formation of free PDLLA homopolymer. Since there are strong hydrogen bonds between PVP and water as well as alcohol, residues of these protic solvents, which interact with the polymer are difficult to remove (Haaf et al. Polymer J. 17:143-152 1985). In the present case, low MW PVP-OH were synthesized in IPA. Therefore, traces of IPA and water molecules might be contained in the polymer. Two drying steps were required for solvent removal. Briefly, at first, PVP-OH was dissolved in toluene and then, an azeotropic distillation was made. Then, the polymer was dried under vacuum at 150° C. over P 2 O 5 for 4 hours. The polymer was actually molten under these conditions, and resulted in a highly dried material.
Molecular weight and PI of PVP-b-PDLLA were determined by SEC using light-scattering and a differential refractometer as detectors (Table 5). As expected, PVP-b-PDLLA MWs were larger than that of corresponding PVP-OH, while PI decreased. Anionic polymerization leads to very small PI {Nagasaki et al. Macromolecules 31:1473-1479 1998; Iijima et al. Macromolecules 32:1140-1146 1999; Yasugi et al. Macromolecules 32:8024-8032 1999). Therefore, the second polymerization step might decrease the PI of the diblock copolymer, suggesting that resulting materials were diblock copolymers and not a mixture of homopolymers. Another plausible explanation of lower PI was that PVP-b-PDLLA having shortest PVP chains were removed by the precipitation in diethyl ether.
The PDLLA contents (% mol) in the diblock copolymers was determined by 1 H-NMR, EA and SEC. A 1 H-NMR spectrum of PVP-b-PDLLA (Diblock-47) copolymer in CDCl 3 is shown in FIG. 7A . The peak at 5.2 ppm corresponds to the —CH— group of PDLLA. Signals from 0.8 ppm to 4.5 ppm were assigned to all protons associated to PVP segment, which overlap the peak of PDLLA methyl group (1.4 ppm). PDLLA content was calculated using equation 1, and results are presented in Table 5. Since traces of water in PVP-b-PDLLA copolymers slightly overestimated the integration of PVP signals, EA was performed and the amount of nitrogen and carbon atoms were used for the calculation of PDLLA content using equation 2. As shown in equation 2 hydrogen atoms of moisture, even from the polymer, are not taken in account into the calculation of PDLLA content by EA. Contrary to 1 H-NMR analysis, EA results were quite constant and reproducible regardless of the moisture content. EA analysis turned out to be suitable for the quantification of PDLLA content into PVP-b-PDLLA. Actually, PDLLA content from NMR data was usually 6 to 8% less than that determined by EA. Although SEC resulted in higher PDLLA contents (about 5%) than EA, the consistence between EA, SEC and NMR were quite good (Table 5).
TABLE 5
Characterization of PVP-b-PDLLA diblock copolymers.
M n
M w
PDLLA
PDLLA
PVP-b-
PVP-OH
SEC
SEC
M w /M n
N M R B
PDLLA
SEC D
PDLLA A
used
(g mol −1 )
(g mol −1 )
SEC
% mol
EA C % mol
% mol
Diblock-47
PVP-OH-
4380
5000
1.14
38
47
54
2500
Diblock-35
PVP-OH-
3840
5030
1.30
27
35
45
2500
Diblock-37
PVP-OH-
8290
10360
1.39
32
37
36
6100
Diblock-39
PVP-OH-
6070
8960
1.48
34
39
44
4000
Diblock-45
PVP-OH-
3770
4860
1.29
37
45
50
2300
A labeling based on PDLLA content into PVP-b-PDLLA diblock copolymers, obtained from EA.
B from equation 1
C from equation 2
D from the M n of PVP-OH and its corresponding PVP-b-PDLLA
Thermogravimetry (TGA) was also a good method for characterizing the diblock copolymer (Liggins et al. Adv. Drug Deliv. Rev. 54:191-202 2002). As shown in FIG. 8 , the trace of solvents (less than 4%) in the diblock polymer was removed below 100° C. FIG. 8 shows a thermogravimetric profile of PVP-b-PDLLA diblock copolymers (Diblock-47). PDLLA in the diblock copolymer was then degraded between 200 to 350° C., followed by the degradation of PVP from 350 to 480° C. Hence, the PDLLA content could also be determined by TGA. For instance, TGA of diblock-45 revealed a PDLLA content of 48% mol, which was in good agreement with EA results.
Because of their amphiphilic properties, the well-defined PVP-b-PDLLA diblock copolymers can self-assemble in aqueous solution to form micelles. The size of micelles was measured by DLS at different concentrations. As shown in FIG. 9 , micelles composed of PVP-b-PDLLA (Diblock-47) in water at a concentration of 2 mg/mL feature a single narrow size distribution of about 40 nm. FIG. 9 shows size distribution of micelles composed of PVP-b-PDLLA (Diblock-47) in water measured by DLS. Upon dilution towards 0.5 mg/mL, no change in the size of micelles was observed. The results indicate that there is no micelle aggregation in the solutions. In contrast, Benahmed et al. (C. Pharm. Res. 18:323-328 2001) reported bimodal size distributions for PVP-b-PDLLA micelles. It has been suggested that the larger population reflects the aggregation of small individual micelles, governed by a secondary order of aggregation. The plausible explanation of the difference is that the molecular weights, PDLLA contents and polydispersity indices reported in Benahmed et al. were higher than the polymers described in the instant application.
Steady-state fluorescence, using pyrene as hydrophobic fluorescence probe, is well used as technique to show the formation of micelles (Zhao et al. Macromolecules 30:7143-7150 1997; Kabanov et al. Macromolecules 28:2303-2314 1995; Wilhelm et al. Macromolecules 24:1033-1040 1991). The polarity of the surrounding environment of the probe molecules affects some vibrational bands in the fluorescence emission spectrum. The changes in the relative intensity of the first and the third vibrational bands (I 338 /I 333 ), which is due to the shift of the (0,0) band from 333 to 338 nm in the emission spectrum have been suggested to examine the polarity of the microenvironment. The CAC of micelles can be determined by this method. After micellar formation, pyrene partitions into the micellar phase and the water phase. Since the core of the micelle is hydrophobic, the intensity ratio of I 338 /I 333 is changed. The extrapolation of tangent of the major change in the slope of the fluorescence intensity ratio leads to CAC. As illustrated in FIG. 10 , PVP-b-PDLLA copolymers exhibited a CAC of about 6 mg/L. FIG. 10 shows the determination of CAC of PVP-b-PDLLA (Diblock 47) in water at 25° C.
The micellization of PVP-b-PDLLA also can be assessed by 1 H-NMR in D 2 O (Benahmed et al. C. Pharma. Res. 18:323-328 2001; Yamamoto et al. J. Controlled Release 82:359-371 2002; Heald et al. Langmuir 18:3669-3675 2002). FIG. 7B shows an 1 H-NMR spectrum of PVP-b-PDLLA (Diblock-47) in D 2 O. As is shown in FIG. 7B , the peaks of the methyl protons (—CH 3 ) and the methine proton (CH—) of PDLLA are highly suppressed while the peaks of PVP still appear in the spectrum, providing evidences of the formation of core-shell structures. The mobility of PDLLA chains in the core is highly restricted, resulting in masking of the PDLLA signals. On the other hand, PVP chains are still observed by 1 H-NMR because of their high mobility as outer shell of micelles.
By combining MCE and IPA as chain transfer agents, PVP bearing one terminal hydroxyl group on one extremity was successfully synthesized by the first polymerization step of the process of the instant invention. PVP MWs were efficiently controlled by changing ratios of either MCE or IPA, to VP. Terminally functionalized low MW PVP were used to efficiently synthesize the PVP-b-PDLLA diblock copolymer by anionic ring-opening polymerization of D,L-lactide in the second polymerization step of the process of the instant invention. PVP-b-PDLLA self-assembled into micelles in water. These micelle-forming copolymers presented very low CAC of a few mg/L, leading to the formation of 40-nm polymeric micelles. These polymeric self-assemblies based on low molecular weight PVP blocks are useful as drug carriers for parenteral administration.
All patents and publications mentioned in this specification are indicative of the levels of those skilled in the art to which the instant invention pertains. All patents and publications are herein incorporated by reference to the same extent as if each individual patent and publication was specifically and individually indicated to be incorporated by reference.
It is to be understood that while a certain form of the invention is illustrated, it is not to be limited to the specific form or arrangement of parts herein described and shown. It will be apparent to those skilled in the art that various changes may be made without departing from the scope of the invention and the invention is not to be considered limited to what is shown and described in the specification.
One skilled in the art will readily appreciate that the present invention is well adapted to carry out the objects and obtain the ends and advantages mentioned, as well as those inherent therein. The methods, procedures and techniques described herein are presently representative of the preferred embodiments, are intended to be exemplary and are not intended as limitations on the scope. Changes therein and other uses will occur to those skilled in the art which are encompassed within the spirit of the invention and are defined by the scope of the appended claims. Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed various modifications of the described modes for carrying out the invention which are obvious to those skilled in the art are intended to be within the scope of the following claims. | The instant invention provides a two-step polymerization process for preparing amphiphilic poly(N-vinyl-2-pyrrolidone), (PVP)-block-polyester copolymers and other diblock and triblock copolymers consisting of PVP as one block. The block copolymers of the invention can be used as vehicles for drug delivery. | 2 |
FIELD OF THE INVENTION
The present invention concerns separation apparatuses and methods, and particularly those systems that separate two or more mixed fluid components through centrifugation.
BACKGROUND OF THE INVENTION
Centrifugal systems of separation use centrifugal force generated through rotation to separate fluid components of differing densities. In many fundamental aspects, these systems are used as a substitute for and improvement on gravitational separation techniques and devices, since the gravitational force and the force exerted on a fluid through rotation (centrifugal) are identical in that they increase in magnitude as the fluid increases in mass. Those fluids with lesser density will be less influenced by the force and therefore less inclined toward the source of the force, the earth for gravitational, the outside of the rotating container for centrifugal, than fluids with greater density. The fluids will thus separate out and can be directed to separate collection ports by using weirs or other suitable separating structures. Centrifugal separation is often more desirable than gravitational because the force applied to the fluid can be controlled through rotation speed and can be made to be many times that of gravity.
A common example of fluid separation is that of oil from water. There are many situations in which separation of these two elements is desired, such as oil spills on an ocean or lake, mixing of the two fluids in ships' bilges, gasoline spills, etc. This process is often important for maintenance of quality of life in a particular geographic area. These two fluids are susceptible to centrifugal separation because water is denser than oil and thus will "sink" relative to the other under application of centrifugal force. This can easily be understood by the fact that oil floats on water in a gravitational field. Other fluid separation applications include wine clarification, waste-water treatment, blood plasma separation, and the like. Centrifugation is also used to separate solids out of liquids through sedimentation.
It is often desirable to separate dissolved elements in solution or emulsion. Standard centrifugal separation equipment alone cannot carry out such a separation since the dissolved elements will move with the solution. A solvent must therefore be introduced into the fluid stream to extract the dissolved elements. Such a process requires that the solvent be thoroughly mixed with the fluid to extract all dissolved elements. The solvent and fluid are then separated through centrifugation. An example of this type of separation is solvent extraction and separation of transuranic elements from radioactive waste streams at nuclear processing plants.
Meikrantz, U.S. Pat. No. 4,959,158, is an example of a typical centrifugal separator in the prior art. In that apparatus, the fluid to be separated is introduced into a space between an inner rotor and an outer stationary housing, where shear mixing of the fluid occurs. A large amount of power is required to maintain the speed of the rotor against the viscous drag of the shearing liquid which makes the apparatus energy inefficient. The power loss increases with angular velocity, limiting the rotor speed.
The rotor is an open top cylinder with the separating weirs at the top. Meikrantz uses the space between the rotor and its housing to introduce the oil-water mixture to be separated. Thus the bottom portion of the space is filled with liquid during operation. The top portion of the space, where the liquids separate and transfer from the rotor to the housing, must contain air for proper operation. (This requires the separator to operate in an upright position). In this space, no seals can be made between the incoming liquid and the air because of the large diameter of the interface; the drag would be unacceptable. This highly agitated air/liquid interface causes the fluid input into the rotor to mix with the air, reducing flow capacity and causing foaming with many substances such as detergents in motor oil. This foaming dramatically reduces the effectiveness of the separator and further increases viscous drag. Meikrantz allows a second air-water interface to exist within the rotor, as a core of air forms radially inward from the first weir, at the center of the rotor. Energetic flow of liquid through the separator causes surface waves to form on this interface, which further degrades the separation process. Additionally, the lighter separated liquid spreads along the full length of the rotor between the air core and the partially defined liquid/liquid interface. This disperse unstable mass is difficult to collect over the relatively short first weir.
OBJECTS AND SUMMARY OF THE INVENTION
It is therefore an object of the present invention to overcome the shortcomings of the prior art.
It is a further object of the invention to input and mix the fluid to be separated without admitting air.
It is a further object of the invention to provide a centrifugal separator which can be made to operate in any orientation.
It is a further object of the invention to minimize fluid motion and contact of fluid with air, and to minimize the power required to operate a separator while maximizing flow capacity.
It is a further object of the invention to optimize the weir structure in centrifugal separators so that the fluid will separate under a wide range of conditions such as various flow rates, different ratios of liquid mixtures, differing component fluid densities, and differing viscosities, and to control air pressure over the weirs and remove formed gases.
It is a further object of the invention to utilize lipophilic surfaces more effectively than in stationary separators.
It is a further object of the invention to utilize optimized weir structures in centrifugal separators so that the fluid will separate under a wide range of conditions, automatically, without need for external control or adjustment, and to control air pressure over the weirs, and remove gases.
It is a further object of the invention to utilize lipophilic surfaces more effectively than in stationary separators, to provide means for controlling fluid motion in the rotor, and to allow for complete automatic draindown and flushing.
It is a further object of the invention to provide a two-stage separator using solvent extraction or other chemical means for separation both of immiscible materials and dissolved materials, removal of foams and emulsions, and to obviate the need for a secondary process.
In accordance with a first aspect of the invention, an apparatus for centrifugally separating into its component parts a mixture having immiscible component parts of a first liquid and a second liquid of differing densities, comprises an elongate inlet shaft having an open receiving end for receiving mixture and an open discharge end through which the mixture is delivered into the apparatus, a rotor disposed substantially coaxially to and surrounding the inlet shaft and adapted for rotational movement thereabout, and a housing surrounding the rotor for receiving and collecting the separated liquids from the rotor. The rotor contains an optional mixing chamber around the inlet shaft with walls comprising the inlet shaft itself and a frustoconical center wall surrounding the inlet shaft, an annular separation chamber which receives the mixture from the mixing chamber, whose inner wall is the frustoconical center wall and whose outer wall slopes oppositely the center wall, and further comprising an annular first weir disposed at the larger end of the separation chamber. A lighter liquid channel is formed between the base of the first weir and the center wall, and a heavier liquid channel is formed between the first weir and the outer wall. A discharge passage for the lighter liquid is provided from the first weir to a collection chamber in the housing. A second weir is formed beyond the first weir for the discharge of the heavier liquid into a second collection chamber in the housing.
In accordance with a second aspect of the invention, a method of centrifugally separating a mixture containing component parts of first and second immiscible liquids comprises the steps of inputting the mixture through an input shaft into the approximate center of a rotatable rotor having a radially outwardly sloping center wall with an annular outer edge surrounding the input shaft, rotating the rotor causing the mixture to move down the slope of the center wall and flow over the edge thereof into a separation chamber formed by the center wall and a coaxial outer wall having an opposite radial slope from the center wall and a first weir disposed oppositely from the center wall edge, separating the mixture into its component parts in the separation chamber, discharging the first liquid from the separation chamber through a first annular channel between the center wall and the first weir, channeling the first liquid to a first collection chamber, discharging the second liquid from the separation chamber through a second segmented annular channel between the outer wall and the base of the first weir, and channeling the second liquid to and over a second weir and into a second collection chamber.
In accordance with a third aspect of the invention, an apparatus for centrifugally separating into its component parts through solvent extraction a liquid mixture, containing first and second immiscible liquids and contaminants dissolved or emulsified in the second liquid, comprises a first separation chamber which separates the immiscible liquids, a first discharge channel for discharging the first liquid into a housing, a mixing chamber for mixing the second liquid with a solvent, a second separation chamber for separating the second liquid from the solvent, and second and third discharge channels for discharging the solvent and second liquid, respectively, into the housing.
In accordance with a fourth aspect of the invention, a method of separating a mixture of first and second liquids into its component parts comprises injecting the mixture into a rotatable rotor, separating the first and second liquids from each other in a first separation chamber, discharging the first liquid from the rotor, injecting a solvent into the rotor, mixing the second liquid with the solvent, separating the second liquid from the solvent in a second separation chamber, discharging the solvent from the rotor, and discharging the second liquid from the rotor.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects, aspects, and embodiments of the present invention will be apparent to those skilled in the art from the following description and accompanying drawing figures, of which:
FIG. 1 is a partial elevational view in cross-section of an example of a single stage centrifugal separator according to the invention;
FIG. 2 is a partial elevational view in cross-section of the separator of FIG. 1 showing an alternative inlet port and vanes in the separation chamber;
FIG. 3 is a view along line 3--3 in FIG. 1;
FIG. 4 is a view along line 4--4 in FIG. 2;
FIG. 5 is a view along line 5--5 in FIG. 1;
FIG. 6 is an elevational view in cross-section of an example of a two stage centrifugal separator according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring first to FIG. 1, a single stage centrifugal separator 10 according to the invention separates a combined stream of two immiscible liquids of differing densities into its component parts. The invention will be described as separating a stream of oil mixed with water, though it will be understood that the invention efficiently separates other fluid combinations. The separator 10 comprises three principal components: a stationary shaft inlet port 12, a rotor 14 adapted for rotational movement around the inlet port 12, and a stationary housing shell 16 surrounding the rotor 14. The components comprise in construction a suitably rigid material such as steel or plastic in the preferred embodiment.
The oil and water mixture enters the separator 10 through a mouth 18 of the stationary shaft 12. This inlet arrangement has the advantage of eliminating contact of the mixture with the air between the rotor 14 and the housing 16, minimizing agitation and foaming which hamper separation. Additionally, the separator 10 can be used in any orientation as long as the output structures are appropriately designed since the oil/water mixture does not enter the space between the rotor 14 and the housing 16, and thus can not interfere with transfer of the separated liquids from the rotor to the housing. Nevertheless, the described embodiment of the separator 10 is intended for use in a vertical position with the fluid combination downwardly traveling through the inlet shaft 12, as shown by the arrows in FIG. 1.
The inlet shaft 12 comprises a single hollow shaft in the single-stage version or a plurality of smaller shafts, such as a bundle of shafts or a concentric arrangement, which will be described later in conjunction with the two-stage embodiment of the invention.
The rotor 14 comprises a rotatable drive shaft 22, located coaxially to and beneath the inlet shaft 12, which is rotated by any suitable means such as a motor and accompanying drive train (not shown). The drive shaft 22 rotates the rotor at a speed determined to be suitable in light of weir structure, relative densities of the fluids being separated, size of the separator components, magnitude of desired centrifugal force, and other factors familiar to those skilled in the art. If desired, the drive shaft 22 may contain a drain channel 24, having a stopper or closure 26 secured therein by threading or other means, for convenient flushing and draindown of the separator 10 by running a suitable cleansing fluid through the inlet port 12, allowing the fluid to run through the separator, and draining the excess through the unstopped drain channel 24.
A center wall 28 rises from the drive shaft 22, creating a mixing chamber 30 where the input fluid is mixed through shearing between the moving center wall 28 of the rotor and the outer wall of the stationary input shaft 12. The mixing chamber 30 has a small volume relative to, e.g., a mixing chamber at the periphery of a separator, minimizing shear resistance and thus the power required to maintain the rotor at the desired speed. The volume of the mixing chamber optionally can be further decreased by mounting a frustoconical protrusion 32 on the stationary shaft 12 or by otherwise building up the volume displaced by the stationary shaft 12 or center wall 28. The mixing chamber may be optionally deleted where the mixing function is not needed as will be further described with reference to FIG. 2. A primary purpose of the mixing chamber is for addition of a conditioning material, such as a solvent for reducing viscosity or for solvent extraction.
The fluid mixture flows with the aid of externally applied pressure and centrifugal force from the mixing chamber, or optionally from the inlet shaft, into the separation chamber 34, formed by the center wall 28 and the coaxial outer wall 36, where the component fluids are separated. The outer wall 36 slopes oppositely from the center wall 28, causing the separated oil and water to move downwardly along the inner and outer walls, respectively, toward the separator's weir structures. The top of the outer wall 36 meets the stationary shaft 12 in annular engagement. At that location, bearings 38 are mounted between the wall 36 and the shaft 12 to enable the rotor 14 to rotate relative to the stationary shaft 12. Shaft seal 80 is provided to protect the bearing from contact with the internal fluids.
FIG. 2 illustrates an alternative inlet port 40 comprising a stationary shaft 42 which differs from the stationary shaft 12 in that it is shorter and capped by a disc 44 which extends out from the shaft 42 as a flange. The input fluid enters the rotor 14 through holes 46 near the bottom of the shaft 42 and in the disc 44. The center portion of the rotor 14 inside the center wall 28 and below the inlet port 40 is sealed off by a top wall 48, whereby the input fluid is shear mixed in the region between the disc 44 and the top wall 48 and the region between the disc 44 and the top of the outer wall 36 before entering the separation chamber 34. The inlet port 40 allows for complete flushing and draindown of the separator without a drain channel in the drive shaft 22, since no liquid collects in the region inside the center wall 28. Optionally, mixing of the input flow may eliminated from the design of FIG. 2 by deleting the shear disk 44.
Referring again to FIG. 1, the oil and water of the input fluid combination separate in the separation chamber 34 owing to the lighter density of oil relative to water. In the field of the centrifugal force created by the rotation of the rotor 14, the oil "rises" radially inwardly toward the center wall 28 while the water "sinks" radially outwardly toward the outer wall 36.
If desired, an optional sieve 50 illustrated in FIGS. 1 and 3 can be mounted between the center wall 28 and the outer wall 36 in the upper portion of the separation chamber 34 to aid the separation. The sieve 50 comprises a plurality of closely spaced, radially oriented plates parallel to the axis of rotation in the preferred embodiment. For oil/water separation, the plates are coated with or formed from a lipophilic material such as polypropylene. While the fluid mixture travels through the sieve 50, finely dispersed or emulsified oil, which may be difficult to separate simply through centrifugal force, condenses on the surface of the plates and is thereby collected and separated from the water. Sieves used in gravitation separators have not been effective since they must be large with widely spaced plates in order to operate in a 1-g field. When used in the separator 10, however, the sieve can be small with closely spaced plates due to the higher magnitude of the g field. These modifications greatly improve separation effectiveness.
The sieve 50 also redirects and aligns the flow of incoming fluid. It has been found effective to guide the fluid in the axial direction to avoid shearing against the center and outer walls 28 and 36. Vanes or ribs 52, illustrated in FIGS. 2 and 4, may alternatively be mounted on the walls of the separation chamber to accomplish the same purpose. The vanes 52 may partially or completely traverse the separation chamber 34 in the radial direction.
As illustrated in FIGS. 1 and 5, the separation chamber 34 contains a weir 54 at its bottom for direction of the separated oil and water. The weir 54 comprises an annular baffle plate attached to and extending from the drive shaft 22 toward the outer wall 36. The plate bends back upon itself to extend toward the center wall 28 before reaching the wall 36, at 54a, creating a segmented annular passage 56 between the bend 54a and the outer wall 36 for the passage of water from the separation chamber 34. The weir plate ends a short distance from the center wall 28, creating an annular passage 58 between the edge of the weir 54 and the center wall 28 for the collection of oil from the separation chamber 34. The bent weir plate creates an intermediate oil collection chamber 59 under the top plate of the weir 54. The oil collected in the intermediate chamber 59 is shunted through a plurality of channels 61 formed through the bend 54a in the weir 54, the water passage 56, and the outer wall 36.
The outer wall 36 bends beneath and parallels the curvature of the weir 54 to shunt the collected water back toward the drive shaft 22. The outer wall 36 ends before contacting the drive shaft 22, thereby forming a second weir 60. An annular groove 62 is formed in the side of the outer wall 36 opposite the water passage 56 to receive wall 84 which divides the collection chambers 78 and 72 that respectively conduct outflows of water and oil. As illustrated in FIG. 1, the outer wall 36 is formed of an upper wall piece 36a and a lower wall piece 36b secured to each other by screws or other means. This component configuration is solely for convenience of construction. The wall 36 may if desired comprise a unitary piece without affecting separation. A sloped outcropping 64 extending from the drive shaft 22 guides water away from the shaft seal 82.
The outflow of separated fluids around the weir 54 is controlled so that a stationary oil/water interface is maintained between the outlets in the passages 56 and 58 during rotation. The interface must not approach either outlet too closely or mixed fluid may be discharged. As in prior art apparatuses, air must be present adjacent the edges of each of the weirs 54 and 60 since separated liquid outflow rates are determined by free-surface flow over the weirs 54 and 60. In the present invention, however, the air/liquid interface at the center of the rotor 14 is largely eliminated by the radially outward slope of the center wall 28, which causes most of the center wall to be radially more outward than the edge of the weir 54, confining the necessary air/oil interface to a narrow pocket region adjacent the edge of the weir 54 where the center wall is sufficiently inward relative to the weir edge to establish a free liquid surface. Thus, the rotor 14 separates substantially all the input liquid without interaction with air and consequent foaming and interference with separation. A similar pocket of air is disposed near the edge of the weir 60. Air ducts 66 formed through the bottom plate of the weir 54 equalize pressure between the two pockets of air and remove excess gases therefrom which form, e.g., by bubbles of air mixed with the input fluid which "rise" to the center wall and migrate along it until they join with the pocket of air near the edge of the weir 54.
The sloping of the center and outer walls 28 and 36 allows the weirs 54 and 60 to be large in relation to overall rotor size, improving flow rate and separation efficiency. The formula for the position of the liquid/liquid (oil/water) interface between the separated liquids in the separation chamber 34 is ##EQU1## where r b is the radial distance of the liquid/liquid interface from the axis of rotation,
r w is the radial distance of the heavier liquid surface over the second weir edge,
r o is the radial distance of the lighter liquid surface over the first weir edge,
p w is the density of the heavier liquid, and
p o is the density of the lighter liquid.
The liquid/liquid interface in the separation chamber 34 must lie between the edge of the weir 54 and the bent portion 54a of the weir to avoid discharge of mixed fluid. This is expressed in mathematical terms as:
r.sub.1 <r.sub.b <r.sub.p, (2)
where
r p is the radial distance of the bent portion 54a of the first weir
r 1 is the radial distance of the edge of the first weir.
Thus, as the distance between the edge of the first weir 54 and the bent portion 54a of the weir increases, the range of possible positions of the liquid interface increases and thus the range of liquid densities that can be separated by the weirs. These relationships can be used to design a weir structure that performs optimally for any particular application.
It has been found that the optimum weir construction for a separator designed to separate common crude oils from water where the crude oils have specific gravities ranging from 0.82 to 0.92 satisfies the following relationship: ##EQU2##
The depth of the liquid over the edge of a weir, indirectly represented in the equations by r w and r o , depends on the relative proportions of the component fluids in the input mixture, viscosity, input flow rate, and speed of the rotor 14. The most effective designs will maintain a shallow flow over the weir edges. Air pressure at the weir edges must be equal in order for the above equations to be valid, accomplished by the air ducts 66 or other equivalent means.
The housing 16 collects the separated liquids from the rotor 14. The housing 16 is a single shaped wall which is formed around the rotor 14 and which completely encloses it. The annular top 68 of the housing, secured to the input shaft 12 by suitable means, extends out horizontally past the rotor 14. A sidewall 70 meets the edge of the top 68 and descends parallel to the outer wall 36 of the rotor. In the described embodiment the sidewall 70 is formed from two pieces 70a and 70b for convenience of construction, which are joined near the bottom of the sidewall 70 by screws or other suitable means in a fashion similar to the outer wall 36 of the rotor.
An oil collection chamber 72 is formed at the bottom of the sidewall 70 to receive the separated oil from the oil channels 61 through the wall 36. A water collection chamber 78 is formed adjacent to and radially inward from the oil collection chamber 72. An intermediate wall 84 is formed between the oil and water collection chambers 72 and 78 to keep the separated fluids apart. The end of the wall 84 fits into the annular groove 62 of the rotor to effectively prevent cross-contamination of the separated fluids. The collection chambers 72 and 78 are provided with attachments (not shown) for connection of pipes or hoses that remove the separated fluids.
The end of the radially inward wall 86 of the water collection chamber 78 fits against the drive shaft 22 underneath the outcropping 64 in annular engagement. Bearings 88 are mounted between the end of the wall 86 and the drive shaft 22 to allow the rotor 14 to rotate within the housing 16. A seal 82 is provided to protect the bearing from the internal fluids.
The separator 10 can be flushed and cleaned by operating it with a cleaning slurry containing water, hexane, and a suitable detergent, or another similar slurry formulation. The weirs and flow channels of the separator are sloped so that no liquid is trapped inside when the separator and the input liquid flow are stopped.
The separator 10 can be made in various sizes, all of which are functionally equivalent except that larger sizes will have a lower angular velocity in equivalent applications. The range of liquids that can be separated remains the same.
FIG. 6 shows a two-stage separator 110 according to the invention. The separator 110 separates immiscible liquids containing dissolved contaminants or immiscible liquids that are resistant to separation, such as those in an emulsion. The one-stage separator 10 is not able to separate out dissolved contaminants in mixed fluids in a single operation. The separator 10 is able to separate fluids resistant to separation to a degree, particularly with the help of the sieve 50, but does so inefficiently. This is the case especially with very stable, finely dispersed colloidal suspensions and solutions.
As is known in the art, a separator such as the separator 10 can be used in two stages to separate immiscible liquids and dissolved contaminants. The immiscible liquids first are separated through the process described above, and the separated liquid containing the contaminants is mixed with a solvent that has a higher affinity for the contaminants, by which means the solvent breaks down the solution or emulsion and absorbs the dispersed contaminant into itself. The solvent and liquid, which preferably are immiscible, are then separated by putting them through the separator 10 a second time. The solvent can conveniently be mixed with the liquid containing the contaminant by putting them into the separator 10 in combination and allowing them to mix through the shear action in the mixing chamber 30 of separator 10 (FIG. 1). If it is required that the liquid be of very high purity, the solvent purification process can be repeated until the desired level of purity is obtained.
Solvent extraction separation is desirable for mixtures such as commercial motor oil mixed with water, since commercial motor oils contain detergents that cause foaming and emulsions. A further example is a mixture of commercial gasoline with water: gasoline formulations contain carcinogenic substances as additives, such as benzene, toluene, ethyl benzene, xylenes, and naphthalene. The additives are slightly soluble in water, allowing a few parts per thousand to exist in solution.
The two-stage separator 110 carries out the required stages of initial separation, solvent extraction, and final separation in a single operation. The separator 110 will be described as separating motor oil mixed in water with the oil containing benzene contaminants which slightly dissolve in water. The solvent used preferably is hexane or, alternatively, pentane. It will be understood that various other mixtures and solvents can be used. The separator 110 is similar in construction to the separator 10 in many aspects, except that, among other differences, it contains two separation chambers with the high-density liquid output of the first chamber continuing into the second, radially more outward, chamber after being injected with a solvent.
The separator 110 comprises a stationary input shaft 112, a rotor 114, and a housing shell 116. The input shaft 112 comprises two coaxial shafts, an inner shaft 118 through which the oil/water mixture enters the separator, and an outer shaft 120 through which the hexane solvent enters. The rotor 114 is driven by a rotatable drive shaft 122 under the power of a motor or other means (not shown). A drain channel 124 having a stopper 126 is provided in the drive shaft 122 for complete flushing and draindown of the separator 110. The center wall 128 of the rotor 114 extends downwardly from its point of origin at the side of the mouth 130 of the inner input shaft 118, and slopes radially outwardly before ending near the top of the drive shaft 122. The center wall 128 is sealed from the outer input shaft 120 by an annular seal 132, preventing solvent from entering the chamber 134 formed by the center wall 128.
An intermediate wall 136 attaches to the top of the rotatable shaft 122 and extends up and radially outward, creating a separation chamber 138 between the intermediate wall 136 and the center wall 128. The input oil/water mixture enters the chamber 134 from the inner shaft 118 and is urged downwardly by external pressure and centrifugal force during rotation. The mixture then flows around the edge of the center wall 128 into the separation chamber 138, wherein the separated components are urged upwardly by the radially outward slope of the intermediate wall 136 (for the water) and the radially inward slope of the center wall 128 (for the oil) toward a weir 140 disposed at the top of the separation chamber 138.
The weir 140 is similar in construction to the weir 54 in the single stage separator 10. The weir 140 comprises a baffle plate which originates from the center wall 128, extends radially outward, and bends back upon itself, creating an annular oil passage 142 between the edge of the weir 140 and the center wall 128. A water passage 144 is formed between the bent portion 140a of the weir and the intermediate wall 136, the latter curving around the weir 140 to continue the passage 144 and form a weir 146. For convenience of construction, the intermediate wall comprises two portions, a lower portion 136a and an upper portion 136b which are joined by welding or other suitable means near the bent portion 140a of the weir 140. An intermediate oil chamber 148 is formed in the interior of the weir 140, and an oil channel 150 is formed through the bent portion 140a of the weir, the water passage 144, and the intermediate wall 136.
The weirs in the two-stage separator 110 are preferably made in accordance with the optimal weir construction previously described.
The separation chamber 138 separates the oil/water mixture, after which the separated oil is directed through the passage 142, into the chamber 148, and through the channel 150. The water is directed into the passage 144 and over the edge of the weir 146. The air pockets over the weirs 140 and 146 communicate through air ducts 152, thereby equalizing their pressure.
An outer wall 156 is provided over the intermediate wall 136 to form an outer water passage 158 over the weir 146, and has air ducts 160 formed therethrough to allow the air pocket over the weir 146 to communicate with the housing space. The end of the outer wall 156 meets the input shaft 112 in annular engagement. Bearings 162 are mounted between the wall 156 and the shaft 112 to allow rotation of the rotor 114 around the input shaft 112. A seal 164 also is provided between the outer wall and the inlet shaft. A lip 166 is formed on the end of the center wall 128 at the point at which it meets the outer wall 156 in order to guide the water around the weir 146 and to direct solvent into the water stream.
A solvent channel 168 is formed at the juncture of the outer wall 156 and the center wall 128 between the outer inlet shaft 120 and the outer water passage 158, supplying hexane solvent into the water stream just above the weir 146. The solvent and water mix in the outer passage 158 to remove emulsions and dissolved contaminants. The solvent channel 168 is directed so that the solvent is introduced into the high-velocity water stream flowing over the weir 146 to facilitate mixing. The weir 146 is formed with an appropriate slope and contour to prevent the water flow from separating from the face of the weir, which facilitates mixing and mitigates weir erosion. All weirs in the various illustrations are intended to illustrate similar slope and contour for this same purpose.
It can be seen that the oil channel 150 continues from the intermediate wall 136 through the outer water passage 158 and outer wall 156 to a collection chamber in the housing 116.
The outer water passage 158 continues down between the intermediate wall 136 and outer wall 156 until it enters a second separation chamber 170 formed between the walls 136 and 156. The separation chamber 170 separates the water from the solvent, which contains the extracted contaminants. The outer wall 156 slopes radially outward to urge the cleaned and separated water down to a weir 172 formed at the bottom of the separation chamber 170 which directs the separated liquids out of the separation chamber 170. Hexane has lesser density than water, so the hexane "rises" radially inward toward and is urged downward by the radially inwardly-sloped intermediate wall 136 while the water "sinks" radially outward against the outer wall 156.
The weir 172 is formed from a baffle plate originating on the drive shaft 122, extending radially outward, bending back on itself, and ending before reaching the drive shaft 122 forming an annular solvent passage 174. A water passage 176 is formed between the bent portion 172a of the weir and the outer wall 156, which curves under the weir 172 and ends to form a weir 178. A solvent channel 180 is formed through the bent portion 172a, passage 176, and outer wall 156 to shunt the collected solvent into the housing 116.
The outer wall 156 is formed from three secured pieces 156a, 156b, and 156c for convenience of construction. An annular groove 181 is formed on the outer side of the lower section 156c.
An outcropping 182 extends from the bottom of the weir 172 around the edge of the weir 178 to guide the water into the housing 116. A small air channel 184 underneath the outcropping 182 leads from the housing air space to a cavity 186. Air ducts 188 lead from the cavity 186 to the air pocket at the edge of the weir 172 to equalize the pressure therein.
The housing 116 comprises a top wall 190 secured in annular attachment to the inlet shaft 112 by welding or other means. The top wall 190 extends horizontally outward over the outer wall 156 of the rotor 114, and a side wall descends from it to form an oil collection chamber 192 below the oil channel 150. The chamber 192 receives and collects the separated oil. An attachment (not shown) to the chamber 192 affords connection to a pipe or hose for discharge of the separated oil.
The radially inward wall 198 of the oil collection chamber 192 descends substantially parallel to the outer wall 156 of the rotor, and forms a solvent collection chamber 200 below the solvent channel 180 for the collection of solvent and accompanying contaminants. An attachment (not shown) to the solvent collection chamber 200 affords connection to a pipe or hose for discharge of the solvent. The discharged solvent may be recycled and reused in the separator 110, if desired.
The inner wall 206 of the solvent collection chamber 200 ends inside the annular groove 181 to effectively prevent cross-contamination with purified water in chamber 208. The wall 206 also serves as the outer wall of the water collection chamber 208 formed beneath the weir 178 for collection of water which has been separated from the oil and additionally purified of benzene or other impurities. In other words, the purified water contains neither immiscibles nor solubles. An attachment (not shown) to the water collection chamber is provided for connection of a pipe or hose for removal of the purified water.
The inner wall 210 of the water collection chamber ends in annular engagement with the drive shaft 122. Bearings 212 are mounted between the wall 210 and the drive shaft 122 to allow the drive shaft to rotate within the housing. An annular seal 204 is placed adjacent to bearings 212 to protect them from the internal fluids.
One run through the separator 110 is sufficient to separate out immiscibles and solubles from the water. If desired, the operation can be repeated in order to achieve a higher level of purity.
It will be understood that many different combinations of liquids can be separated by the separator 110. It will also be understood that the different auxiliary structures described with regard to the separator 10 such as the sieve 50 and vanes 52 can also be used beneficially in the separator 110. The present invention includes modifications and variations of the described embodiments, which constitute only a few examples of how the invention may be applied in practice. | An apparatus and method for centrifugally separating a mixture of liquids comprises a central inlet shaft, a surrounding rotor, and a housing shell. The mixture is injected into the rotor through the inlet shaft and the rotor separates the mixture in a radially sloped separation space containing a first weir, discharges the lighter liquid into the housing through a channel through the weir and wall of the separation chamber, and discharges the heavier liquid into the housing over a second weir. The inlet shaft may be built up to provide for efficient shear mixing and a sieve may be provided in the separation chamber. A two-stage separator may be constructed by providing a second separation chamber radially outward of the first after mixing of a separated liquid with a solvent and providing suitable discharge ports. | 1 |
BACKGROUND OF THE INVENTION
This invention relates to pliers. More particularly it relates to specialized pliers for closing a locking ring.
A unique locking ring has been developed by George W. Jensen and it, together with a pneumatic clenching tool, are described and claimed in U.S. Pat. No. 4,476,616 the disclosure of which is hereby incorporated herein by reference. The Jensen locking ring was developed primarily as an improvement over the Hog ring. The Jensen locking ring utilizes a pair of locking loops which are on different planes from one another. It is particularly useful in applications requiring great strength such as, for example, holding gabions together where the locking ring must withstand hundreds of pounds of force. As shown in U.S. Pat. No. 4,476,616, a pneumatic tool was developed to interconnect the loops thus clenching the locking ring. The pneumatic tool utilizes a die having a pair of oppositely-tapered grooves for providing the clenching operation. Furthermore, a magazine containing a plurality of locking rings is normally utilized with the pneumatic tool making that system high-speed.
However, there is a need for an inexpensive and easy to use apparatus for clenching the Jensen locking ring where the speed of operation is not a great limiting factor.
Various pliers and other tools have been developed for closing staples and rings such as hog rings. Examples of such tools are described in U.S. Pat. Nos. 2,562,097 issued to Heuer, 2,299,858 issued to Sorenson, 1,848,763 issued to Baringer, and 3,507,305 issued to Crabb; however, the devices shown in those patents are not suitable to clench the Jensen locking ring.
OBJECTS OF THE INVENTION
Therefore, it is one object of this invention to provide improved pliers for clenching a locking ring.
It is still another object to provide pliers for clenching a locking ring which are inexpensive and easy to use.
It is still another object to provide a mechanism for clenching a locking ring which is uncomplicated and reliable.
SUMMARY OF THE INVENTION
In accordance with one form of this invention, there is provided pliers having first and second handles, each of which has a jaw element. A mechanism is provided for pivoting the handles in a plane of rotation relative to one another. A mechanism is further provided for moving the jaw elements in a direction normal to the plane of rotation.
In the preferred embodiment of the invention, the mechanism for moving the jaw elements in the direction normal to the plane of rotation includes a pair of inclined planes on each handle which come in contact with one another as the free ends of the jaw elements are moved towards one another.
A spring mechanism may be provided for urging the handles together and a further spring mechanism may be provided for maintaining the jaw elements in a predetermined position for proper spacing when initially receiving and holding an unclenched locking ring.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial front perspective view of the pliers of the subject invention.
FIG. 2 is a partial top perspective view showing the pliers of FIG. 1 with the jaws a first position relative to one another.
FIG. 3 is a partial side elevational view showing a portion of the pliers of FIG. 2.
FIG. 4 is a partial side elevational view of the pliers of FIG. 3 showing the jaws in a second position relative to one another.
FIG. 5 is a side elevational view of the Jensen ring which may be clenched by the pliers of FIG. 1.
FIG. 6 is a partial rear elevational view of the pliers of FIG. 2 showing the Jensen ring contained therein.
FIG. 7 is a partial front elevational view of the pliers of FIG. 4 showing the Jensen ring in the closed or clenched position.
FIG. 8 is a simplified vector analysis diagram of the motion of each of the jaw elements of the pliers relative to their plane of rotation.
FIG. 9 is a partial top view of the pliers of FIG. 4 position.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now more particularly to FIG. 1, there is provided pliers 10 having first handle 12 and second handle 14. Handle 12 includes jaw element 16 and handle 14 includes jaw element 18. Jaw elements 16 and 18 include free ends which are moved toward and away from one another. The handles pivot about a rod 20 which is better seen in reference to FIG. 2. Rod 20 is received in a bore hole which penetrates completely through handles 12 and 14. Rod 20 includes head 22. Portions of rod 20 are threaded so as to receive threaded nut 24. Leaf spring 26 is attached to rod 20 for urging jaws 16 and 18 toward one another in a direction normal to the plane of rotation of handles 12 and 14. Coil spring 28 is wrapped around rod 20 and is retained on the rod by means of washer 30. The ends of coil spring 28 are attached to handles 16 and 18 at holes 32 and 34. Coil spring 28 urges the free ends of the jaw elements towards one another in the plane of rotation of handles 12 and 14. The importance of this feature will be explained below.
Referring again to FIG. 1, jaws 16 and 18 include grooves 36 and 38 which are adapted to receive a ring and preferably the Jensen locking ring, an example of which is shown in FIG. 5 as item 40.
As can be seen from FIG. 5, the locking ring 40 includes locking loops 42 and 44 which are not on the same plane with one another. Therefore, in order to clench or close the ring, the locking loops must be forced to interconnect with one another.
Referring again to FIG. 1, handle 12 includes elongated groove 46 while handle 14 includes elongated groove 48. Groove 48 may be better seen in reference to FIG. 6. Inclined planes 50 and 52 respectively form the sloped upper walls of grooves 46 and 48 respectively. As the free ends of the jaw elements are moved toward one another by the movement of handles 12 and 14, inclined planes 50 and 52 contact one another causing the jaw elements 16 and 18 to move in a direction normal to the plane of rotation of the handles. Thus the grooves 36 and 38, which are preferably in slightly different planes prior to the movement of the free ends of the jaw elements toward one another also move in a direction normal to the rotation plane causing the locking loops 42 and 44 to move towards one another and align with one another in a common plane at the time of clenching. FIG. 2 shows the grooves 36 and 38 out of line prior to the movement of the free ends of the jaw elements toward one another and FIG. 9 shows that the grooves are in slightly different planes after the free ends of the jaw elements have been moved towards one another. Preferably during closure the grooves pass through the same plane at some position. A vector analysis of this movement of jaws and grooves is shown graphically in FIG. 8.
Horizontal line 53 represents the rotating plane of the jaws relative to one another, while line 54 represents vertical motion normal to plane 53. The resultant vector of the horizontal and vertical movement is indicated by line 56. The inclined planes 50 and 52 rise from the bottom of elongated grooves 46 and 48 at an angle with respect to center line of the handles and the plane of rotation of the jaws. Preferably the angle with respect to the plane of rotation is 45° and the angle with respect to the center line of the handle is preferably 25°.
Referring now to FIG. 3, the jaw elements are resting against one another at the bottom of grooves 46 and 48 because of the action of leaf spring 26 pressing against screw head 22. This maintains the grooves 36 and 38 slightly out of alignment to make it easier to insert a locking ring between the jaws.
Referring now to FIG. 4, with the free ends of the jaw elements 16 and 18 having been moved toward one another, that is, with the inclined planes 50 and 52 in contact with one another and running up on one another, the jaw elements separate from one another in particularly at grooves 46 and 48, exposing middle portion 58 of rod 20. As can be seen in FIG. 4, spring member 26 is in its compressed state and less of the end of the rod 20 near screw head 24 is exposed than in FIG. 3.
Referring now more particularly to FIG. 7, the Jensen ring 40 has been clenched by the joining of locking loops 42 and 44 and as can be seen, a portion of jaw element 18 has ridden up on inclined plane 50 of jaw element 16 resulting in the configuration shown in FIG. 4.
Referring back now to FIG. 1, threaded rod 58 is received through a threaded bore hole (not shown) in handle 12. Handle 14 includes groove 60. As can be better seen in FIG. 7, end 62 of rod 58 is received in groove 60 thereby providing a stop so that one cannot close the Jensen ring 40 too far. The threaded on rod 58 enables the jaws to be adjustable as to the degree of closure. In order to prevent the opening of the jaws too far, shoulders 64 and 66 are provided on handles 12 and 14 respectively forming the bottom vertical wall of grooves 46 and 48. The opposite handle will abut against the shoulders if one were to try to open the jaws too far.
As described above, the preferable locking ring to be used with the above-described pliers is the Jensen locking ring referred to in U.S. Pat. No. 4,476,616 the disclosure of which is hereby incorporated herein by reference. The Jensen locking ring is an open ring of material of a type which imparts spring resilience to the ring and may be made out of material such as steel. As shown in FIG. 6, the ring has a center section of two substantially straight links 66 and 68. The center section includes a bend 70 between the links forming an angle of greater than 90°, but less than 180°. Second and third bends 72 and 74 are also provided and have angles of less than 90°. Arms 76 and 78 extend from the second and third bends and then from the links. The sum of the three angles is greater than 180° but less than 360°. Each arm 76 and 78 is on a different plane from the center section. The locking loops 42 and 44 form continuous arcs of at least 120° but less than 360°.
The above-described pliers is specifically adapted to clench the above-described Jensen locking ring in an efficient and economical manner. The pliers are durable and easy to use and require almost no maintenance.
From the foregoing description of the preferred embodiment of the invention, it will be apparent that many modifications may be made therein. It is intended that the appended claims cover all such modifications as falls within the true spirit and scope of the invention. | There is provided specialized pliers particularly adapted to close a locking ring which has locking members on the different planes. The pliers include a pair of jaws, each having grooves for receiving the locking ring. Inclined planes, which abut against one another as the jaws close, are provided on both jaws for moving the jaws normal to their plane of rotation thus bending the locking ring so that the locking mechanism will be interconnected. Spring elements are provided for maintaining the jaws in a predetermined position relative to one another. | 1 |
This is a continuation of U.S. patent application Ser. No. 276,356 filed Oct. 23, 1988 entitled Vehicle Article Carrier which is a continuation of Ser. No. 213,899 filed 6-30-88, U.S. Pat. No. 4,877,186 issued 10-31-89, entitled Vehicle Articles Carrier; which is a continuation of Ser. No. 003,134, filed 1-14-87, U.S. Pat. No. 4,754,905, issued 7-5-88, entitled Vehicle Article Carrier; which is a continuation of Ser. No. 778,385 filed 9/20/85, U.S. Pat. No. 4,684,048 issued 8-4-87, entitled Vehicle Article Carrier.
BACKGROUND AND SUMMARY OF THE INVENTION
The present invention relates generally to vehicle article or luggage carriers and more particularly to a new and improved vehicle luggage carrier of the type shown in applicant's U.S. Pat. No. 4,099,658, issued Jul. 11, 1978. Generally, the article carrier of the present invention is of the type which comprises two or more slat-type elements which are fixedly secured to an exterior horizontal surface of an automotive vehicle, such as a vehicle roof or a trunk lid, and which are permanently attached to that surface and adapted to have ancillary article constraining members removably and/or adjustably secured thereto and includes a system of adjustable and fixed components which cooperate with one another and which may be removable in some instances.
The present invention has as one principle object to provide a luggage rack with slidably adjustable and fixedly engageable components including slidably adjustable cross members having tie downs for boxes, luggage, and the like associated with the cross members. The cross members and tie downs of the present invention are not only adjustble but also may be either removable from the luggage carrier or stored within other components of the luggage carrier substantially out of view. Each cross member may include at least one tie down and/or abutment member for optimum securement of articles or luggage to the article carrier and thereby the vehicle.
A significant advantage of the article carrier of the present invention is that the article carrier has a low profile when not in use with minimal structure projecting above the plane of the vehicle surface to which the article carrier is attached, thereby minimizing any adverse wind noise or fuel economy effects that would exist with any portion of the carrier being substantially vertically elevated.
The present invention further incorporates all of the aesthetically appealing features and the myriad of functional features and optional accessories disclosed in the slat-type luggage carriers of applicant's prior patents, such as that described in U.S. Pat. No. 4,099,658, referenced above.
Even more notably, the present invention elevates the aerodynamic design of a vehicle article carrier system having adjustable and/or removable components to an improved design not previously attained by any prior art carriers. The elongated support member or slat of the present invention providing the foundation of the carrier has surfaces which flow into and integrate with the surface of the vehicle, but also includes a channel along which components may be adjusted and/or removably attached.
In cooperatio with this improved support member or slat, a new and improved looking mechanism for attaching the adjustable and/or removable components of the system to the member or slat is included having an aerodynamic, hidden release element.
Additional advantages are provided in the combination of the above features with other fixed components of an article carrier system and an improved cross member construction integrating adjustable tie down and/or abutment disposeable out of view, similar to those described in applicant's U.S. Pat. No. 4,460,116, issued Jul. 17, 1984, and further integrating a pad construction in a cross rail spaced from a functional channel onload bearing cross members for a more stable yet cushioned load bearing support for articles disposed on the cross members.
Other objects and advantages of the present invention will become apparent from the following detailed description taken in conjunction with the following drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary perspective view of an automobile showing an article carrier mounted thereon which is constructed in accordance with the principles of the present invention;
FIG. 2 is an enlarged sectional view of the support member portion of the structure illustrated in FIG. 1 taken along the line 2--2 thereof;
FIG. 3 is an enlarged sectional view of the support member portion of the structure illustrated in FIG. 1 taken along the line 3--3 thereof;
FIG. 4 is an enlarged sectional view of one of the front stanchion portions of the structure of FIG. 1 taken along the line 4--4 thereof;
FIG. 5 is an elevated enlarged fragmentary view of one of the front stanchion assemblies of FIG. 1 taken in the direction of arrow 5.
FIG. 6 is a cross-sectional view of the cross rail portion of FIG. 5 taken along the line 6--6 of FIG. 5;
FIG. 7 is an elevated enlarged fragmentary view of one of the rear stanchion portions of the structure of FIG. 1 taken in the direction of arrow 7;
FIG. 8 is a cross-sectional view of the cross rail portion of FIG. 7 taken along the line 8--8 of FIG. 7;
FIG. 9 is a cross-sectional view of the rear stanchion of FIG. 7 locked to the base support member or slat of FIG. 1;
FIG. 10 is a cross-sectional view similar to FIG. 9 of the rear stanchion of FIG. 7 released from the base support member or slat of FIG. 1;
FIG. 11 is a view similar of FIG. 4 of the rear stanchion of FIG. 9 looking in the direction of arrow A in FIG. 9 having portions broken away;
FIG. 12 is a view similar to FIG. 11 of the rear stanchion of FIG. 10 looking in the direction of arrow B in FIG. 10 having portions broken away;
FIG. 13 is a vertical sectional view of either FIG. 6 or FIG. 8 along the line 13--13 of either view of the tie down disposed in the cross rail of either view; and
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now in detail to FIG. 1 of the drawings, a vehicle luggage carrier 20 is shown in operative association with a generally horizontally disposed roof 22 of a typical automotive vehicle 24. Generally speaking, the lugage carrier 20 comprises a pair of laterally spaced, longitudinally extending support members or slats 26 and 28 which are secured upon the roof 22 at positions adjacent the lateral sides or edges thereof. In the embodiment illustrated, the members 26 and 28 are disposed over the seam where the roof 22 meets the remainder of the body portion of the vehicle, where the roof 22 has a downward curvature, which places the members 26 and 28 adjacent the horizontally extending surface portion of the roof 22. The members 26 and 28 have an external surface configuration that flows aerodynamically and smoothly in the surface of the vehicle 24.
Intermediate portions of the member 26 (or 28) are illustrated in cross-section in FIGS. 2 and 3. The member 26 comprises first 30 and second 32 exterior surfaces having an elongated channel 34 between the surfaces. The channel 34 comprises an elongated recess 36 and a liner 38 disposed in said recess 36 by means of, with reference to FIG. 3, fasteners 35 set through bores 37 in the liner and bores 39 in the recess 36. The liner 38 has upper article supporting surfaces 40, 42 disposed on a pair of inwardly directed upper flanges 44, 46, a pair of sidewalls 48, 50 extending downwardly therefrom, and a base 51 extending between the walls 48, 50 and integrated with the walls 48 and 50 via walls 52 and 53, respectively. The upper flanges 44, 46 are rolled back as illustrated in FIGS. 2 and 3 to provide grooves 45 and 47 in the interior of the channel 34 for the purposes as will be described below. The fasteners 35 are set below the surface of the base 51 by placement in recesses 55, as shown in FIGS. 3 and 4.
Referring to FIG. 2, a pad 54 is disposed between each of the members 26 and 28 and the roof 22. Each member 26 or 28 is secured to the roof 22 by a plurality of threaded collar studs 56 threadably engaged to the member 26 or 28 within a bore 58 and engaged with the roof 22 at the interior of the roof 22 through a plurality of holes 60 in the roof by means of a plurality of nuts 62. The studs 56 engage the members 26 and 28 at the plurality of bores 58 by augering into the members 26 and 28, which are plastic in the preferred embodiment, or by other conventional means. In this manner, the studs 56 are all hidden from view when the members 26 and 28 are assembled on the vehicle.
The article carrier 20 of FIG. 1 further comprises a pair of transversely or laterally extending cross member assemblies 70 and 72 and may also include a tie down 73 and a plurality of intermediate supporting slats 75. The front cross member assembly 70 comprises a pair of stanchions 74 and 76 telescopically engaged with and secured to a front cross rail 78. Referring to FIG. 4, the stanchion 74 (and likewise 76) is fixedly secured to the support member 26 (and 28) via two posts 80 and 82 which fit into two bores 84 and 86 at the front portion of each of the members 26 and 28 and via two bolts 88 and 90 fitting through recesses 92 and 94 and apertures 96 and 98 in each of the stanchions 74 and 76 into corresponding threaded bores 100 ad 102 in the members 26 and 28.
The stanchions 74 and 76 have an aerodynamically streamlined curvature as illustrated in FIGS. 1, 4, and 5 and telescopically engage the front cross rail 78 in a similarly aerodynamically streamlined manner. Referring to FIGS. 4 and 6, the cross rail 78 comprises a bottom surface 1∝from which a curved leading surface 106 and a curved trailing surface 108 extend upwardly. The upper surface 110 of the cross rail 78 comprises a series of elongated article supporting surfaces including surfaces 111 and 112 disposed one on each side of an elongated first channel 114 and a surface 116 disposed on an elongated front bumper 118 set into a second channel 120 in the rail 78. The bumper 118 has a pair of elongated flanges 122 and 124 on the underside thereof to secure the bumper in the second channel 120.
Referring to FIGS. 4 and 6, the first channel 114 has an interior cross-section having a base 126, a pair of sidewalls 128 and 130, and a pair of interior clamping surfaces 132 and 134. Within the first channel 114 (FIG. 6) is disposed a tie down/positioning member 136 similar to that disclosed in applicant's U.S. Pat. No. 4,460,116, issued Jul. 17, 1984. The tie down/positioning member 136 (FIGS. 6 and 13) is comprised of an upper section 140 having a vertically disposeable abutment surface 142 and an aperture 144 therein, a base portion 146 including spring biasing members 148, and a pivot 150 for pivotably associating the upper section 140 with the base portion 146. The upper section 140 also includes a lower cam member 151 on the opposite side of the pivot 150 which engages the base 126 of the first channel 114 with pivotal movement of the upper section 140 from the horizontal to the vertical and clamp the biasing members 148 against the clamping surfaces 132 and 134 and lock the tie down/positioning member 136 in any selected position along the length of the first channel 114. The ends of the channel 11 also include an abutment 152 (FIG. 5) to aid in disposing the upper section 140 from the horizontal to the vertical.
The rear cross member assembly 72 is adjustable to any selected position along the length of the members 26 and 28, as determined by a stop 154 (FIGS. 4 and 5) or by the end of the channel 34, and may also be removed, if desired. The assembly 72 (FIGS. 1 and 7) comprises a pair of stanchions 160 and 162 telescopically engaged with and secured to a rear cross rail 164. The stanchions 160 and 162 each engage a corresponding support member 26 or 28 at the channel 34 thereof via a locking mechanism 166 (FIGS. 9 through 12). The locking mechanism 166 comprises a pivoted lever 168 mounted to each stanchion 160 or 162 within a recess 170 and secured to a pin 172. The lever 168 is limited in movement by a stop 169 (FIG. 11) to indicate a vertically disposed portion for the lever 168. The pin 172 threadably engages the lever 168 in a bore 175 and communicates with the interior 174 of the stanchion and engages an eccentric member 178 disposed in the stanchion interior 174 via a bore 176 at a position offset from the center of the member 178 to eccentrically move a pin 180 mounted on the member 178 at bore 181. Referring to FIGS. 11 and 12, the pin 180 moves within a yoke 182 which is integrated with a hook 184. Guides 186 and 188 may be disposed one on each side of the yoke 182 to stabilize the linear vertical movement of the hook 184. The hook 184 is formed with a curvature to permit some resiliency. Further tension is applied to the hook 184 by a tensioning member 186 fixedly disposed adjacent the path of movement of the hook 184 as illustrated in FIGS. 9 and 10.
In operation, the stanchion 160 or 162 is placed over the channel 34 of the support member or slat 26 and the hook 184 is placed within the channel 34. The stanchion 160 or 162 also includes front and rear alignment posts 188 and 190 (FIG. 7) which are also placed within the channel 34 of the stanchion is set upon the upper surfaces 40 and 42 of the member 26 or 28. Once alignment is attained, the lever 168 is rotated from a horizontally disposed position (FIG. 10) to a vetically disposed position (FIG. 9) abutting against the stop 169 and lifting the hook 184 so that its leading edge 192 is engaged with the groove 47 of the channel 34 to clamp the stanchion 160 or 162 to the support member of slat 26. The return of the lever 168 to a horizontal disposition releases the hook 184 and the stanchion 160 or 162 from the member of slat 26 for adjustment or removal.
Referring to FIGS. 7 and 8, the rear cross rail 164 is similar to the front cross rail 78 in that it has a bottom surface 194 from which a curved leading surface 196 and a curved trailing surface 198 extend upwardly. It should be noted that the leading surface 196 and trailing surface 198 may be reversed, however, depending upon the selected placement of the rear cross rail assembly 72 on the membes 26 and 28. The upper surface 200 of the cross rail 164 comprises a series of elongated article supporting surfaces including surfaces 202 and 204 disposed one on each side of an elongated first channel 206, a surface 208 disposed on an elongated front bumper 210 set into a second channel 212 in the rail 78 and an additional surface 213. The bumper 210 has a pair of elongated flanges 214 and 216 on the underside thereof to secure the bumper in the second channel 212.
Referring to FIG. 8, the first channel 212 has an interior cross-section having a base 226, a pair of sidewalls 228 and 230, and a pair of clamping surfaces 232 and 234. Within the first channel 212 is disposed a tie down/positioning member 136 again similar to that disclosed in applicant's U.S. Pat. No. 4,460,116, issued Jul. 17, 1984. The tie down/positioning member 136 is again comprised of an upper section 140 having a vertically disposeable abutment surface 142 and an aperture 144 therein, a base portion 146 including spring biasing members 148, and a pivot 150 for pivotably associating the upper section 140 with the base portion 146. The upper section 140 also includes a lower cam member on the opposite side of the pivot 150 which engages the base 226 of the first channel 212 with pivotal movement of the upper section 140 from the horizontal to the vertical and clamp the biasing members 148 against the clamping surfaces 232 and 234 and lock the tie down/positioning member 136 in any selected position along the length of the first channel 212. The ends of the channel 212 also include an abutment 252 (FIG. 7) to aid in disposing the upper section 140 from the horizontal to the vertical.
While it will be apparent that the preferred embodiment of the invention disclosed is well calculated to fulfill the objects above stated, it will be appreciated that the invention is susceptible to modification, variation and change without departing from the proper scope or fair meaning of the subjoined claims. | An article carrying system for operative association with an automotive vehicle having an exterior generally horizontal surface, such as a trunk lid or roof, the system comprising a pair of elongated support members or slats which have a configuration which flows conformably and aerodynamically into the surface of the vehicle and which are permanently secured to the vehicle. The support members have longitudinally extending channels for supporting adjustable and/or removable components of the system, including tie downs and cross members which components are also provided with aerodynamic designs compatible with the remainder of the system. Provision is also made for association of components of the system, such as cross members, to be fixedly located on the support members. An aerodynamic locking mechanism is also disclosed for use in selected adjustable and/or removable components of the system which includes a hidden actuation mechanism and a hooking action to lock the component to the support member or slat. | 1 |
FIELD OF THE INVENTION
This invention relates generally to greeting cards and note cards more particularly to a kit containing the requisite components for making such cards and/or envelopes to contain the same. The invention also relates to a method for manufacturing a greeting card, note card, or an envelope from paper stock.
BACKGROUND OF THE INVENTION
Greeting cards and/or note cards have long been used by people to express their emotions to others. Typically, one desiring to send a greeting card or a note card to another must travel to a store and purchase a decorative card containing a message printed thereon. Alternatively, one may desire to purchase a note card or stationary which is primarily blank but is decorated in an aesthetically pleasing manner, and on which can be written a personalized message. For example, such cards may be decorated to correspond to a certain theme such as a baby shower or a wedding. Although a wide variety of greeting cards or note cards are available, it is sometimes difficult to find a card containing the desired message or theme. The store-bought cards may also not include a variety of themes and are not customized for an individual or by the sender.
Also, greeting cards and note cards have become increasingly expensive. This has led some to manufacture their own cards containing the desired message or theme. This has also led to the recent development of machines which are placed in card shops and which allow consumers to manipulate text and artistic images to custom design a card. The above attempted solutions to the problem of not being able to find a desirable greeting card or note card are not entirely satisfactory. The latter method utilizing the machines, is an expensive method, is not available in all areas, and still requires that one travel to a store. The former method of manufacturing greeting cards or note cards without the aid of a kit, leads to cards which often do not have the desired professional appearance.
SUMMARY OF THE INVENTION
The present invention is therefore directed to a kit containing the required elements to enable one to manufacture his or her own greeting cards, note cards, or envelopes. The invention also discloses a method of manufacturing a greeting card, note card, or an envelope from ordinary paper stock or from paper stock containing decorative scenes or material thereon. An example of decorative paper stock which may be suitable for use with the kit is the glossy decorative paper stock which is used within some magazines. The kit is preferably provided in booklet form and comprises envelope template means for forming an envelope from a piece of paper stock. The kit preferably further comprises card template means for forming a card from a piece of paper stock. The kit preferably further comprises a plurality of pieces of paper stock which have decorative scenes printed thereon, being suitable for use in manufacturing cards and envelopes. The kit preferably also includes a plurality of pieces of plain or colored paper stock which is suitable for use in forming envelopes and cards and which also provides a suitable writing surface.
In another preferred embodiment, the invention may further comprise stickers or other adhesive components designed to facilitate the assembly of the card and/or the envelope. The kit may further comprise address labels which preferably are self-adhesive and are designed to be adhered to the face of an envelope to facilitate the addressing of the envelope or the return addressing of the envelope.
The present invention is also directed to a method of manufacturing a greeting card, note card, and/or an envelope from paper stock.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the kit of the present invention in its preferable booklet form;
FIG. 1A is a plan view of the open booklet shown in FIG. 1;
FIG. 2 is a perspective view of an envelope manufactured using the kit and method described herein;
FIG. 2A is a plan view of a page including an envelope template;
FIG. 2B is a plan view of an alternative envelope template to that shown in FIG. 2A;
FIG. 3 is a perspective view of a card manufactured using the kit and methods described herein;
FIG. 3A is a plan view of a page including a card template;
FIG. 3B is a plan view of an alternative card template; and
FIG. 4 depicts a page of the kit of the present invention as containing address and assembly stickers which are preferably provided with the kit.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The kit of the present invention is shown generally as booklet or magazine 10 in FIG. 1, though the contents of the kit may be provided in any suitable form. Booklet 10 preferably contains a plurality of pages 12 which are, or contain thereon, various elements of the kit as will be described hereinbelow, and also preferably includes instructions on a page 12 describing how the kit may be utilized to manufacture envelopes, greeting cards, note cards, or the like. Pages 12 are preferably releasably disposed in booklet using means known in the art to allow pages 12 to be easily removed from booklet 10. For example, booklet pages 12, as seen in FIG. 1A, include perforations 18 at their respective inner edges near binding 16 to allow pages 12 to be easily separated and removed from the booklet 10. Other suitable means to allow the pages 12 to be removed are contemplated or, alternatively, pages 12 may simply be cut from booklet 10.
As seen in FIG. 2, an envelope 20 may be formed using envelope template 22a, 22b as respectively shown in more detail in FIGS. 2A and 2B. Envelope templates 22a, 22b are included on pages 12 of booklet 10 which are preferably made from a heavy paper stock or cardboard, although a various other suitable materials, such as plastics, exist and may be utilized. Pages 12 containing envelope templates 22a, 22b are preferably similarly releasably secured within booklet 10 using perforations or a variety of other means, which include, for example, securing pages 12 within booklet 10 with an adhesive or with a special binding means to allow envelope templates pages 12 to be easily removed from booklet 10.
Envelope templates 22a, 22b are preferably drawn or otherwise defined or indicated on pages 12 by one or more perimeter lines 24 (shown as solid lines) printed, embedded, or otherwise disposed on at least one surface of a page 12. Envelope templates 22a, 22b are preferably provided with at least one "fold-line" 25 (shown as broken lines) printed or otherwise indicated on at least one surface thereof as a dashed line or otherwise distinguishable from perimeter lines 24. In an alternative embodiment, the one or more perimeter lines 24 may be suitably formed by scoring, perforating, or otherwise to form a weakened zone in the template sheets to allow templates 22a, 22b to be easily removed from their respective pages 12. Although perimeter lines 24 and/or fold lines 25 are preferably provided on templates 22a, 22b, booklet 10 may be provided with blank envelope template sheets from which one may cut, or upon which one may draw, an envelope template 22a, 22b having any alternate configuration they desire.
To use either of envelope templates 22a, 22b to manufacture an envelope 20, one must first select a suitable piece of envelope paper stock which is preferably provided with the kit 10. The envelope paper stock is preferably a high quality paper which may be colored or have aesthetically pleasing graphic material, such as a decorative scene or image, on at least one surface thereof. Booklet 10 preferably contains a plurality of pieces of suitable envelope paper stock having different graphic material disposed thereon as pages 12, which allows one having a kit to easily select a desired piece of paper stock. In the preferred embodiment, the paper stock may include a glossy photographic scene, theme oriented graphics, or other decorative pictures as desired, although a plain piece of envelope paper stock may be utilized. In addition to the envelope paper stock provided as pages 12 of booklet 10, a wide variety of other paper stock is usable with envelope templates provided in the kit to make a suitable envelope. For example, many magazines utilize glossy paper stock having a wide variety of images thereon which correspond to the theme of the magazine. These pages may be cut or otherwise removed from a magazine to be utilized as envelope paper stock.
When a suitable piece of envelope paper stock has been selected, it is temporarily secured adjacent to a page 12, which contains an envelope template 22a, 22b indicated thereon, using a plurality of paper clips or other such fasteners, so that the perimeter lines 24 of template 22a, 22b remain visible. Using scissors or a sharp implement, one cuts along the perimeter lines 24. Alternatively, the one or more perimeter lines can be formed as weakened zones by scoring or perforating, and the template 22a, 22b may be easily separated from the page 12. The perimeter of the template 22a, 22b may then be traced upon a piece of envelope paper stock, which may then be cut to the proper shape to form envelope 20. Alternatively, rather than tracing template 22a, 22b, one may simply cut a piece of envelope paper stock to conform to the perimeter of template 22a, 22b. After being cut with the help of template 22a, 22b, the envelope paper stock has the required shape to be formed into an envelope 20. This is preferably accomplished by folding envelope paper stock along fold-lines 25 after the above cutting operation is complete. Folding of envelope paper stock preferably occurs while envelope paper stock is fastened to envelope template 22a, 22b however, envelope paper stock may alternatively be separated from template 22a, 22b prior to any folding operations. Flaps a, b, c are preferably folded inward relative to each other along fold lines 25a, 25b, 25c, respectively, and are fastened, using a glue stick, paste, stickers, staples, or others means known in the art, over at least a portion of the points where they meet to form envelope 20. Rubber cement is an example of one suitable adhesive which may be utilized to manufacture envelope 20.
Booklet 10 is also preferably provided with a page 12 including a plurality of address labels 40, as seen in FIG. 4, which may be applied to the front 21 of envelope 20, as seen in FIG. 2, or the back of envelope 20 to provide a suitable surface upon which to write the address or the return address. The address labels 40 may also be used to seal envelope 20 if applied to seal the rear flap 23. As an alternative to using address labels 40, envelope paper stock may be provided with an undecorated area for writing an address or a return address. Booklet 10 preferably further comprises a plurality of sealing stickers 42, as seen in FIG. 4, which may be used for sealing the rear flap 23 of envelope 20 for delivery and/or may be used in place of glue or other fastening means to secure flaps a, b, c when assembling envelope 20. Address labels 40 may also be used to secure flaps a, b, c when assembling envelope 20.
Those skilled in the art will recognize that many different shapes of envelopes are ultimately obtainable by providing envelope templates 22a, 22b with different perimeter lines 24 and/or different fold lines 25. Because envelope templates 22a, 22b will be cut or otherwise separated from page 12 after their first use, templates 22a, 22b may be re-used by tracing their perimeter onto a piece of paper stock and subsequently cutting the paper stock along the tracing lines, or by temporarily being fastening the template 22a, 22b adjacent to a piece of paper stock which may be trimmed to conform to perimeter shape of template 22a, 22b. In an alternative embodiment, perimeter lines 24 of an envelope may be provided directly on a piece of envelope paper stock to allow an envelope 20 to be removed directly therefrom without use of a template 22a, 22b. The perimeter lines 24 of envelope template 22a, 22b may be simply printed for cutting out the envelope 20, or be provided as weakened zones on a piece of envelope paper stock. This would allow one to separate the envelope template 22a, 22b from the remainder of the page and fold the template 22a, 22b into an envelope 20. In such an embodiment, the envelope 20 could be provided with a suitable adhesive, such as a self-stick adhesive or a pressure sensitive adhesive including a protective release strip thereon. The adhesive would be applied to allow one to simply assemble an envelope 20.
Booklet 10 preferably also includes the required elements to manufacture a greeting card, note card, or other such card as seen at 35 in FIG. 3. Card templates 30a, 30b are drawn, defined, or otherwise indicated on pages 12 of booklet 10 which are preferably made from a heavy paper stock or cardboard, although various other suitable materials such as plastic may be used. Pages 12 containing card templates 30a, 30b indicated thereon are preferably releasably secured within booklet 10 using perforations (not shown) or a variety of other means, which include, for example, binding pages 12 within booklet 10 with an adhesive, or by using any other suitable binding to allow pages 12 to be easily removed from booklet 10.
One or more card templates 30a, 30b are preferably defined by one or more perimeter lines 32 (shown as unbroken lines) printed, embedded, or otherwise disposed on at least one surface of page 12. Card templates 30a, 30b are also preferably provided with at least, one "fold-line" 34 (shown as broken lines) printed or otherwise indicated on at least one surface of page 12 as a dashed line or otherwise distinguishable from perimeter lines 32. As discussed above in relation to envelope templates 22a, 22b, perimeter lines 32 may be formed as weakened zones in page 12 to allow the template 30a, 30b to be easily removed from the sheet.
Booklet 10 preferably also includes card paper stock to be used in conjunction with card templates 30a, 30b to form a card such as a note card, greeting card, or other such card. Card paper stock is preferably a high quality paper stock which is designed to provide a suitable writing surface. Card templates 30a, 30b are preferably of the size and shape so as to allow a card to be produced which can be used with envelope 20 made using envelope templates 22a, 22b. Booklet 10 also preferably includes a variety of pictures or other aesthetically pleasing decorative images formed on high quality glossy paper. If one desires to decorate card 35, these images are designed to be cut from booklet 10 and pasted, glued, or otherwise disposed upon the formed card 35 such as on the front surface 36. The portion of the decorative image which overhangs front 36 of card 35 may be trimmed to provide an aesthetically pleasing card 35 to be used with envelope 20.
To form card 35, one selects a suitable piece of card paper stock which is preferably provided as a sheet or page 12 in booklet 10. Card paper stock may be provided in pre-cut sheets which are sized to correspond to envelope 20 made according to the above description, but card paper stock is preferably provided in the form of 81/2"×11" sheets. To form a card 35, one may simply cut a piece of card paper stock into the size and shape desired, without using a card template 30a, 30b. For example, one may simply cut a piece of 81/2"×11" card paper stock horizontally at its midsection to form two cards, each 41/4"×51/2" in size. Those skilled in the art will recognize that card paper stock or envelope paper stock may provided in any number of shapes and sizes, and may be cut into other shapes and sizes as desired, and the invention is not limited to the arrangement disclosed. Card paper stock may alternatively be formed into a desired shape using either of card templates 30a, 30b. Card templates 30a, 30b are used in a manner similar to envelope templates 22a, 22b as described above, to allow one to form a card 35 having the desired shape. One of the card templates 30a, 30b may be temporarily secured, using paper clips or other suitable temporary fasteners, adjacent to a piece of card paper stock. Using a scissors or other cutting implement, one simply cuts along the perimeter lines 32 to form a card 35 of the desired shape. Alternatively, the perimeter lines 32 of card template 30a, 30b may be formed in a page 12 the sheet by scoring, perforating, or otherwise to form a weakened zone in page 12. Template 30a, 30b may then be removed from page 12 and its outline may be traced onto a piece of card paper stock which may be subsequently cut into a card 35, or, card template may be temporarily secured adjacent to a sheet of card paper stock which may then be trimmed to conform to the shape of the perimeter of the card template 30a, 30b. Card templates 30a, 30b are preferably designed to allow two cards to be clot from each piece of 81/2"×11" card paper stock. As has been previously mentioned, the use of card templates 30a, 30b is optional. Card 35 may simply be cut from card paper stock in any shape desired, and folded in any suitable manner known in the art. Card template 30a, 30b perimeter lines 32 and/or fold lines 34 may be indicated directly on a page 12 of card paper stock to allow a card 35 to be cut directly therefrom. Also, card template 30a, 30b perimeter lines 32 may be formed as weakened zones in a piece of card paper stock to allow a card 35 to be easily removed from the remainder of the piece of card paper stock.
Booklet 10 preferably also includes retaining means, such as pocket 14, elastic band 15, clips, or others, for selectively retaining and storing the various elements of the kit, and other supplies while the elements or supplies are not in use. For example, envelope templates 22a, 22b, card templates 30a, 30b, paper stock, or adhesive labels 40, 42 may be secured in pocket 14 or with elastic band 15 or using other retaining means known in the art. Alternatively, a carrying case may be provided to conveniently carry booklet 10, and any other supplies such as scissors, rubber cement, clips, paper, and the like.
Based upon the foregoing, the kit of the invention provides all materials necessary to create a greeting card and an envelope, allowing the user to tailor make a card 35 for a particular occasion, or to, make a card 35 based upon a particular theme. The kit for creating a greeting card 35 allows the card 35 to be personalized for a particular occasion or event, with the kit including a variety of decorative materials, such as photographic images or other graphics or art work, which may be combined into a unique, one-of-a-kind card relating to a particular occasion or event, or relating to a particular person to whom the card 35 is to be sent. The decorative sheet material may also be provided with printed messages or the like relating to the occasion or event if desired. The kit includes the sheet materials which may be used in the construction of both the creating card or note card 35, as well as an envelope 20 used for mailing the card 35, with card and envelope pages constructed to provide rigidity or other characteristics to facilitate use as a card 35 or envelope 20. Decorative or graphic material may be placed on paper stock used to form the note card 35 or envelope 20, or the graphic material itself may be printed on materials suitable for these purposes. Matching or similar pictures, where one may be a faded or faintly drawn version of the other may be provided on card paper stock and envelope paper stock to allow one to manufacture a card 35 and a matching envelope 20. The paper stock may include, for example, Cartoon images to be colored in by a child. A variety of stencils may also be provided with the kit to allow one to decorate the paper stock as desired. Paper stock may be provided which includes different recipes or other information printed thereon.
A variety of different shaped templates may be used to create distinctive note card 35 or envelope 20 patterns from a blank sheet of material, and enable the user to create a card 35 and envelope 20 pair having a professional appearance. The kit preferably also includes address labels 40, stickers 42, seals 42, or other means to allow the constructed card 35 and envelope 20 to be sealed and mailed easily, with all resources necessary to create a finished, professional looking card 35 and envelope 20 set provided with the kit. It should be recognized that the kit provided in the form of a magazine-type booklet 10 allows materials in the kit to be directed to a particular theme or occasion. For example, the kit may include creations for all occasions such as for birthdays, congratulations, or other special events, with material relating to each theme presented as part of the magazine kit. Alternatively, the kit may be directed to a particular theme or occasion, such as birthday cards, Christmas cards or the like, with a variety of decorative or graphic material provided in the kit relating to the particular theme or occasion. As part of the material used to form a greeting card or note card 35, pages 17 in the kit may be provided with other materials, such as stickers, lace, or other decorative materials which are releasably secured within the booklet 10. Providing the kit with a variety of different decorative materials will allow the user to create a card 35 having a meaning with respect to a particular theme or occasion, or personalized for an individual, allowing a great amount of flexibility in design and use. Further, forming the kit in the form of a magazine or booklet 10 allows easy and convenient storage of the kit between uses, and allows a wide variety of decorative or graphic materials to be incorporated easily along with the kit. Providing the additional materials of address labels 40, seals 42, stickers 42, and the like also provide a finished, professional appearance to a created card 35, and simplifies use of the kit.
Those skilled in the art will recognize that cut-lines and/or fold-lines may be printed or otherwise disposed on at least one side of the envelope paper stock, and/or card paper stock to allow an envelope 20 or a card respectively, to be cut directly therefrom. Those skilled in the art will recognize that booklet 10 may be provided in the form to manufacture only envelopes 20 or cards 35, to be used with a card or envelope, respectively, of other origin, such as may be purchased. While the foregoing description has set forth the preferred embodiment of the invention in particular detail, it must be understood that numerous modifications, substitutions and changes can be undertaken without departing from the true spirit and scope of the present invention as defined by the ensuing claims. | The present invention is directed to a kit containing the required elements to enable one to manufacture his or her own greeting cards, note cards, and/or envelopes. The invention also relates to a method of manufacturing a greeting card, note card, or an envelope from ordinary paper stock or from paper stock containing decorative scenes thereon. An example of decorative paper stock which may be suitable for use with the kit is the glossy decorative paper stock which is used within some magazines. The kit is preferably provided in booklet form and includes templates to assist one in manufacturing cards and/or envelopes. The kit typically includes pieces of paper stock which have decorative scenes printed thereon which are suitable for use in manufacturing cards and envelopes. The kit typically will also include numerous pieces of plain or substantially plain paper stock which are suitable for use in forming envelopes and/or cards and which have a writing surface. Various stickers may be provided in the kit. For example, plain or substantially plain stickers may be provided and adhered to the envelope to allow one to write an address thereon. Also, decorative stickers may be provided and be used to assemble the envelope or seal the envelope after a card or letter is placed therein. | 1 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of priority to U.S. Provisional Patent Application Ser. No. 61/555,948, filed Nov. 4, 2011, incorporated herein by reference.
FIELD
[0002] The scope of this disclosure includes electron photoemission of potassium intercalated graphene-based materials for photovoltaic/thermionic power generation.
BACKGROUND
[0003] Traditional absorption refrigeration processes can be driven entirely by heat without the need for intermediate conversion to electrical and/or mechanical power; consequently, the hardware tends to be simpler than competing forms of refrigeration such as vapor-compression cycles. However, evaporative cooling cycles suffer from large volume and only moderate efficiency, and they have, to date, always involved the desorption/adsorption or evaporation/condensation of at least one working fluid.
SUMMARY
[0004] This disclosure presents the use of electrons as the ‘working fluid’ in conjunction with a solid nanomaterial that hinders electron coupling to the atomic lattice of the nanomaterial (i.e., they are out of equilibrium). The electrons can achieve very high effective temperatures with minimal heating of the solid lattice. These ‘hot’ electrons emit from the absorbing material, carrying both the light energy and energy acquired from the atomic lattice. Even electrons that are insufficiently excited to produce direct emission have a long lifetime and may be re-excited without relaxation such that they can emit. Thus, the operation of this disclosure includes shining light on an object to make the object cool instead of heat. It is envisioned that one of ordinary skill in the art would find the operation quite counter-intuitive.
[0005] The present disclosure includes a material comprising: a carbon allotrope doped with boron nitride and an alkali metal intercalated within the carbon allotrope.
[0006] The present disclosure also includes a material comprising: a carbon allotrope, the carbon allotrope selected from the group consisting of graphene and graphite, an alkali metal intercalated within the carbon allotrope, the material subjected to irradiation, the irradiation sufficient to emit an electron with non-zero kinetic energy.
[0007] The present disclosure also includes a method of producing potassium intercalated graphene, the method comprising, providing a substrate, placing the substrate in a microwave plasma chemical vapor deposition chamber, providing hydrogen gas to the chamber, exposing the substrate to plasma, providing methane gas to the chamber, placing product in an evacuated tube along with potassium metal, heating the metal to produce melting and sublimation such that potassium vapor permeates the tube, maintaining a cold environment near the product such that the potassium condenses on the product, cooling the entire system and removing an intercalated product.
[0008] The present disclosure also includes a method of synthesizing boron nitride doped potassium intercalated graphene, the method comprising: providing a substrate, placing the substrate in a microwave plasma chemical vapor deposition chamber, elevating the substrate above a molybdenum puck, providing hydrogen gas to the chamber, exposing the substrate to plasma, providing methane gas to the chamber, placing product in an evacuated tube along with potassium metal, heating the metal to produce melting and sublimation such that potassium vapor permeates the tube, maintaining a cold environment near the product such that the potassium condenses on the product, cooling the entire system and removing an intercalated product.
[0009] The present disclosure also includes an apparatus for transferring heat activated by radiation, comprising, a cathode comprising a substrate of graphite, the graphite being intercalated with an alkali metal, the cathode graphite having a plurality of electrons that are not in thermal equilibrium with the cathode graphite lattice, said cathode having opposing inner and outer surfaces; an anode comprising a substrate of graphite, wherein substantially all of the electrons of the anode graphite are in thermal equilibrium with the anode graphite lattice, said anode having opposing inner and outer surfaces; a member maintaining a gap between said cathode inner surface and said anode inner surface, said member being substantially non-conductive of electricity; wherein the transfer of from said cathode to said anode is activated by reception of the radiation on said cathode.
[0010] The present disclosure also includes a method for transferring heat activated by radiation, comprising, providing a cathode including graphite and an anode; modifying the graphite to have a plurality of electrons with reduced work function, irradiating the modified cathode with the radiation; emitting the reduced work function electrons from the cathode by said irradiating; receiving the emitted electrons by the anode; and removing heat from the cathode by said emitting.
[0011] It will be appreciated that the various apparatus and methods described in this summary section, as well as elsewhere in this application, can be expressed as a large number of different combinations and subcombinations. All such useful, novel, and inventive combinations and subcombinations are contemplated herein, it being recognized that the explicit expression of each of these combinations is unnecessary.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Some of the figures shown herein may include dimensions. Further, some of the figures shown herein may have been created from scaled drawings or from photographs that are scalable. It is understood that such dimensions, or the relative scaling within a figure, are by way of example, and not to be construed as limiting.
[0013] FIG. 1A is a graphical representation of electron energy distribution measurements illustrating FWHM vs. optical intensity of solar simulator for varying emitter temperatures.
[0014] FIG. 1B is another graphical representation of electron energy distribution measurements illustrating FWHM vs. optical intensity of solar simulator for varying emitter temperatures.
[0015] FIG. 2A is a scanning electron microscope photographic representation of graphene petals.
[0016] FIG. 2B is another scanning electron microscope photographic representation of graphene petals.
[0017] FIG. 3A-1 is a cross-sectional schematic representation of a heat exchanger according to one embodiment of the present disclosure illustrating a cooling process according to one embodiment of the present disclosure.
[0018] FIG. 3A-2 is a schematic representation of a heat exchanger according to one embodiment of the present disclosure.
[0019] FIG. 3B is another schematic representation of a heat exchanger according to another embodiment of the present disclosure.
[0020] FIG. 3C is a cross-sectional schematic representation of a heat exchanger according to another embodiment of the present disclosure.
[0021] FIG. 3D is a cross-sectional schematic representation of a heat exchanger according to another embodiment of the present disclosure.
[0022] FIG. 3E is a cross-sectional schematic representation of a heat exchanger according to another embodiment of the present disclosure.
[0023] FIG. 4 is a cross-sectional schematic representation of a heat exchanger according to another embodiment of the present disclosure.
[0024] FIG. 5A is a cross-sectional schematic representation of a heat exchanger according to another embodiment of the present disclosure.
[0025] FIG. 5B is a cross-sectional schematic representation of a heat exchanger according to another embodiment of the present disclosure.
[0026] FIG. 6 is a schematic representation of an instrument measuring emission distributions caused by optical and/or thermal excitation.
[0027] FIG. 7 is a schematic of a multi-stage photo-field emission device for solar-based refrigeration according to one embodiment of the present disclosure.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0028] For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates. At least one embodiment of the present invention will be described and shown, and this application may show and/or describe other embodiments of the present invention. It is understood that any reference to “the invention” is a reference to an embodiment of a family of inventions, with no single embodiment including an apparatus, process, or composition that should be included in all embodiments, unless otherwise stated. Further, although there may be discussion with regards to “advantages” provided by some embodiments of the present invention, it is understood that yet other embodiments may not include those same advantages, or may include yet different advantages. Any advantages described herein are not to be construed as limiting to any of the claims.
[0029] The use of an N-series prefix for an element number (NXX.XX) refers to an element that is the same as the non-prefixed element (XX.XX), except as shown and described thereafter The usage of words indicating preference, such as “preferably,” refers to features and aspects that are present in at least one embodiment, but which are optional for some embodiments. As an example, an element 1020 . 1 would be the same as element 20 . 1 , except for those different features of element 1020 . 1 shown and described. Further, common elements and common features of related elements are drawn in the same manner in different figures, and/or use the same symbology in different figures. As such, it is not necessary to describe the features of 1020 . 1 and 20 . 1 that are the same, since these common features are apparent to a person of ordinary skill in the related field of technology. This description convention also applies to the use of prime (′), double prime (″), and triple prime (′″) suffixed element numbers. Therefore, it is not necessary to describe the features of 20 . 1 , 20 . 1 ′, 20 . 1 ″, and 20 . 1 ′″ that are the same, since these common features are apparent to persons of ordinary skill in the related field of technology.
[0030] Although various specific quantities (spatial dimensions, temperatures, pressures, times, force, resistance, current, voltage, concentrations, wavelengths, frequencies, heat transfer coefficients, dimensionless parameters, etc.) may be stated herein, such specific quantities are presented as examples only, and further, unless otherwise noted, are approximate values, and should be considered as if the word “about” prefaced each quantity. Further, with discussion pertaining to a specific composition of matter, that description is by example only, and does not limit the applicability of other species of that composition, nor does it limit the applicability of other compositions unrelated to the cited composition.
[0031] What will be shown and described herein, along with various embodiments of the present invention, is discussion of one or more tests that were performed. It is understood that such examples are by way of examples only, and are not to be construed as being limitations on any embodiment of the present invention. It is understood that embodiments of the present invention are not necessarily limited to or described by the mathematical analysis presented herein.
[0032] Several embodiments of the present disclosure use electrons as the ‘working fluid’ using a solid nanomaterial that hinders electron coupling to the atomic lattice (i.e., they are out of equilibrium) such that the electrons can achieve very high effective temperatures with minimal heating of the solid lattice.
[0033] In this disclosure, photonic irradiation (whether from a solar source including from filtered solar light or from a non-solar source such as a low-cost light emitting diode) provides the energy that heats electrons, with minimal lattice heating. FIGS. 1A and 1B show derived results from electron energy distribution measurements. The abscissa (x) axis represents the percentage of 1 sun as created in the lab by an AM1.5 solar simulator while the vertical scale contains the ‘full width half maximum’ (FWHM) of the main portion of the electron energy distribution as measured by a specialized instrument in our laboratory. As illustrated in FIG. 6 , this instrument is comprised of a custom vacuum system with an electron energy analyzer attached. The emitter sample is situated such that custom optical and thermal excitation can be applied. The electron energy analyzer measures the energy-resolved electron emission distributions caused by optical and/or thermal excitation.
[0034] As illustrated in FIG. 1A , the light intensities are low—less than or equal to 1 sun on the surface of the earth. As illustrated in FIG. 1B , the light intensities are still relatively low—less than, equal to, or about 20% more than 1 sun on the surface of the earth.
[0035] For such low intensities (<1 sun), only minimal (˜10 degrees K) increases in lattice temperature would be expected. The FWHM of the electron distribution is known to be directly proportional to absolute temperature (˜300 K at room temperature). Therefore, if the electrons and lattice were in equilibrium (or nearly so), then the increase in the FWHM with increasing light intensity would be envisioned as almost imperceptible on the graph.
[0036] However, the experiments shown in FIGS. 1A and 1B illustrate a marked upward trend. In fact, for the unheated sample of FIG. 1A (labeled FWHM 22 C which equals 295 K), the FWHM increases by approximately 50%. The FWHM increase suggests an electron temperature near 500 K. FIG. 1A also illustrates that the heated samples (labeled FWHM 100 C=373 K) show lower FWHM (and thus lower electron temperature) for virtually all intensities. This observation serves to reinforce the central hypothesis because higher lattice temperatures are known to increase electron scattering with lattice energy carriers (called phonons), and this increased coupling would tend to pull the electron temperature closer to the lattice (observed) temperature.
[0037] While the light intensities shown are low, it is envisioned that much higher light intensities will perform in a similar or possibly even a better way. We note the non-linearity of FWHM with increasing light intensity in FIGS. 1A and 1B . We envision the possibility of using solar concentration, by any means ranging from parabolic mirrors to microlenses, to enhance this effect.
[0038] Additional thermodynamic advantages may be achievable by concentrating the light beyond the 1 sun level. A sketch of concepts involving (a) parabolic mirror concentrator and (b) a microlens array attached to the collector is shown in FIG. 5 . The parabolic mirror concept would capture more total light, whereas the microlens array would be very compact and could enhance the local absorption of light to create even higher electron temperatures that would improve thermodynamic efficiency and capacity. We envision that these concentrators could alternatively be located behind the emitter electrode. Regardless the electrode through which light passes would need to be highly transparent.
[0039] We envision that the light source need not be solar. If high efficiencies are realized, we envision using a high-efficiency light-emitting diode integrated into or near the emitter substrate as the driving light source for an ultra-compact cooler. Alternatively, we envision the use of very hot thermal sources such as heated refractory materials as the principal source of electromagnetic irradiation.
[0040] Graphene has emerged as an important material with diverse prospective applications. Widely used graphene synthesis techniques include: mechanical exfoliation, chemical exfoliation, epitaxial growth over SiC, and chemical vapor deposition (CVD). Mechanical exfoliation was the first reported technique and gives high-quality films. Both chemical exfoliation and SiC growth are multistep processes. The CVD technique is a single-step process and offers promise for large-scale graphene growth and meeting the projected demand for graphene production.
[0041] It is envisioned that nanoscale thin-graphite (or multi-layer graphene) petals absorb the light and transfer the photonic energy to electronic energy. The nanoscale thin-graphite (or multi-layer graphene) petals that cover surface as shown in FIGS. 2A and 2B . The petals are pre-treated with potassium (K), which becomes intercalated between the graphite or graphene layers in order to decrease the energy required for electrons to emit (the so-called work function, φ). The work function is the minimum energy that must be given to an electron to liberate it from the surface of a particular substance. The photoelectric work function is:
[0000] =hf 0
[0042] where h is Planck constant and f 0 is the minimum (threshold) frequency of the photon required to produce photoelectric emission.
[0043] In the photoelectric effect, electron excitation is achieved by absorption of a photon. If the photon's energy is greater than the substance's work function, photoelectric emission occurs and the electron is liberated from the surface. As is well understood, excess photon energy results in a liberated electron with non-zero kinetic energy.
[0044] As is illustrated in FIGS. 3A-1 and 3 B, one embodiment of the present disclosure pertains to processes that provide, with the aforementioned understandings, a cooling phenomenon. The process of emitting electrons with very high energies can be used to create a cooling effect in the emitting material. In other words, the high energy electrons are removed out of the graphene-based materials and then are received in a collecting electrode. It is envisioned that the electrons may traverse through vacuum or may traverse through vacuum with trace amounts of intercalant gas. As is illustrated in FIGS. 3A-1 and 3 B collecting electrode may be optically transparent in some manifestations of the disclosure.
[0045] High energy emitting electrons are replaced by low-energy electrons near the electrochemical potential of the emitter in order to conserve charge. Thus, the net energy exchanged by an emitting and replacing pair of electrons is negative. High energy emitting electrons carry net thermal energy away from the emitter producing a refrigerating effect at the emitter. As an additional advantage of this system, this continuous cycle of electron replenishment obviates the need for regeneration of the absorbate as used in some absorption cooling systems. As with all refrigeration cycles, the cooling effect at the evaporating side is offset by a heating effect at the condensing side; therefore, the collecting electrode's temperature would become elevated. However, collecting electrode heating occurs at a place that may be separated by a good thermal insulator, such as vacuum. Due to use of a good thermal insulator, thermal backflow losses are expected to be relatively small as compared to, for example, thermoelectric coolers.
[0046] A sketch of the central concept involving concentrated solar irradiation is shown in FIGS. 3A-1 and 3 B. The envisioned process according to one embodiment of the present disclosure, and as shown in FIGS. 3A-1 and 3 B, includes a coolant fluid that passes across the refrigerated emitter. This coolant fluid delivers cooling to elements that require low temperatures—possibilities include heat exchangers in HVAC systems, electronic components, and refrigeration units for perishable items. The heated collector side is cooled by conventional fans or cooling liquids. We also note here the use of an optional and supplemental electrical power supply that can manipulate the cooling effect by changing the relative electrochemical potentials of the emitter and collector. We also have conceived of the use of a thermoelectric power generator attached to the heated collector side to scavenge some of its waste heat in order to provide this supplemental electrical power. As shown in FIG. 5 , the use of light concentration, by any means ranging from parabolic mirrors to microlenses, can enhance this effect (noting the non-linearity of FWHM with increasing light intensity in the graph above). The parabolic mirror concept would by necessity be voluminous but could capture more total light, whereas the microlens array would be very compact and could enhance the local absorption of light to create even higher electron temperatures that would improve thermodynamic efficiency and capacity.
[0047] Some embodiments of the present disclosure could be used to provide cold air conditioning in remote, rural, or impoverished areas that either have no or unreliable electrical power source. To make the concept fully independent of external electrical power, a simple solid-state thermoelectric generator could be added to the heated collector as shown in FIG. 4 .
[0048] One advantage of this approach is that it could use common, inexpensive materials relative to most photovoltaic power generators which require a separate refrigeration unit. This approach has no requirement for complex mechanical parts such as a compressor or fluid flow elements such as a condenser, evaporator, valves, or seals. We envision the use of modules that are attached like window air conditioning units, although they would be much thinner, lighter, and less bulky. If high efficiency could be achieved, then large-scale commercial markets would open to this approach such as home cooling and rooftop solar-AC panels for hybrid cars.
[0049] Fluid-based absorption refrigeration is undergoing a mild resurgence with increased public attention to energy efficiency. The use of photovoltaics coupled with refrigeration units is possible. One aspect with this approach is that the many losses exist in the many energy conversion processes, which also require several types of technologies and can be expensive. In particular, solar light can be considered a low-potential/high-current DC energy source. However, rotator machines such as compressors are moderate-potential/moderate-current AC energy devices. Finally, the actual cooling process can be considered to be low-potential/high-current, just as was the original solar energy. As a result of this incongruence, the photovoltaic-to-refrigeration route is inefficient; however, the present disclosure retains the low-potential/high-current nature of these phenomena.
[0050] The most recent work related to this effort has focused on further chemical and physical modifications of the nanoemitter material in order to increase electron emission intensity and limit deintercalation of potassium in the graphite lattice.
[0051] We have already shown that a non-equilibrium electron state is present with potassium intercalated graphene petals, which will allow for very high-energy emitted electrons. Two main modifications of the current emitter arrays are envisioned and in development. First, the doping of boron nitride modified carbon, C x (BN) is envisoned. This process involves the heating of the carbon sample, for example by microwave, in the presence of solvated boric acid and urea. The solvent can be either water or methanol. BN modified petals may offer the possibility of an enhanced non-equilibrium state of the electrons owing to a high density of domain boundaries between carbon and BN. This process also has the potential benefit of minimizing potassium deintercalation via reduced mobility of potassium atoms within the graphite lattice. The graphene petals may be modified by a microwave-assisted acid treatment of equal parts boric and urea acids, followed by annealing in a high temperature nitrogen environment. Electron emission experiments are envisoned to compare non-modified petals to the C x (BN) structures.
[0052] Chemical vapor deposition has shown promise for large scale synthesis of doped large-area graphene films. Microwave plasma CVD (MPCVD) is another promising technique that has been widely used for low-temperature and fast growth of different carbon based nanostructures including flat graphene films and graphene flakes. The coupling between methane/hydrogen plasma and a metal foil in the MPCVD process enabled a very rapid and localized heating of the metal foil to produce graphene growth within a few minutes without any supplemental heating. Because of this localized heating on a thermally light substrate (i.e., an elevated foil), the cooling process was also shown to be extremely fast.
[0053] The second variation of the emitter array will be the growth of graphene petals on carbon nanotube (CNT) arrays. Petal coated CNTs generate a very high surface area emitter array with high electrical and thermal transport. This material type may offer an increased current density.
[0054] In parallel to this work, an experimental testing rig for measuring electronic cooling is being developed. A self-contained current density testing system is envisioned and in development similar to what is shown in FIG. 7 . The testing rig is a small pipe or box that has a viewport for solar illumination, and gate valve with flange for attaching to an external pump. Within the emission testing system, a simple circuit including a thermally isolated cathode and anode arrays is present with a thermocouple for measuring temperature changes in the cathode during electron emission. Some possible additions to this design may be a thermocouple on the anode, and a heater attached to the cathode. The reason for developing a small, self-contained testing device is due to known concerns with potassium intercalation. Potassium is known to have a very volatile reaction with oxygen and water vapor. Potassium will readily oxidize in air limiting the efficiency of the cathode material during emission. Potassium intercalation needs to be performed in an inert environment (argon or nitrogen), after which the small testing rig allows for building of the circuitry within a glove box containing an equally inert environment. Once the sample is intercalated and loaded into the field emission testing rig, the gate valve keeps the rig sealed until an external pump is attached and the system is pumped to vacuum.
[0055] FIG. 3B is a cross-sectional schematic representation of a heat exchanger according to one embodiment of the present disclosure. Heat exchanger 60 includes a cathode 70 and an anode 80 spaced apart by a member 66 . Member 66 maintains a gap 67 between the inner surface of cathode 70 and the inner surface of anode 80 . In some embodiments, member 66 is fabricated from a material that is both electrically insulating and thermally isolating, so as to maintain thermal and electrical isolation between anode 80 and cathode 70 .
[0056] Preferably, in a three-dimensional structure gap 67 represents an enclosed volume. In some embodiments, the volume between cathode 70 and anode 80 is evacuated and substantially void of matter. However, in yet other embodiments, the vacuum within this interior volume includes some amount of the substance that is intercalated into the graphite of cathode 70 . Preferably, this additional amount of the substance is in a gaseous phase, although other embodiments contemplate the substance being in a non-gaseous state and adsorbed onto any of the boundaries (cathode inner surface, anode inner surface, and spacing member inner surfaces) of the volume. In still further embodiments, spacing member 66 includes a fluid communication port, through which additional amounts of the intercalated substance can be provided during the life of the heat exchanger, and further, through which the amount of vacuum within the interior can be adjusted.
[0057] Preferably, the spacing 67 is generally uniform between opposing planar inner surfaces of the cathode and anode. However, in yet other embodiments, the present disclosure contemplates nonplanar cathodes, nonplanar anodes, and further contemplates nonuniform separations between the cathode and anode. As one example, in some embodiments, cathode 70 has a generally cylindrical cross-sectional shape, and is generally surrounded by an anode having a generally cylindrical cross-sectional shape.
[0058] Further, the plan shape of heat exchanger 60 can be of any type. In some embodiments, the plan shape (i.e., the shape that would be seen looking down in FIG. 3B ) is rectangular, whereas in other embodiments it is circular, and generally is unconstrained in terms of its plan shape. Further, although discrete heat exchangers are shown and discussed herein, it is further contemplated that these heat exchangers can be distributed and integrated into the overall design of a product, providing heat transfer to that product at the distributed and discrete locations.
[0059] Cathode 70 includes graphite that is intercalated with a substance that lowers the work function of some of the electrons of the cathode graphite. In some embodiments, the graphite includes graphene petals, whereas in other embodiments the graphite includes carbon nanotubes. Yet further embodiments contemplate the use of buckyballs or any form of nanodimensional carbon. Preferably, the graphite is in overall thermal equilibrium with the outer surface of cathode 70 , and further at substantially the same electrical potential as the outer surface of cathode 70 .
[0060] However, as previously described, the intercalation of a substance within the graphite causes some regions of the graphite to be in substantial non-equilibrium. In some embodiments, the intercalated substance lowers the work function of one or more nearby electrons within the lattice of the graphite, and these electrons are not in thermal equilibrium with the local latticework. As discussed earlier, these nonequilibrium electrons are hotter than their surrounding carbon lattice.
[0061] Anode 80 preferably includes a layer of graphite on the inner surface. In some embodiments, this inner surface of graphite has a line of sight to the inner surface of cathode 70 . Therefore, as the nonequilibrium electrons are emitted from cathode 70 , the transport directly and by shortest distance to anode 80 . However, yet other embodiments, the present disclosure contemplates one or more electromagnetic devices within heat exchanger 60 (such as within separating member 66 ) that can be used to change the transport path of the non-equilibrium electrons after being emitted by cathode 70 . For example, separating member 66 can include one or more electromagnets that can be used to concentrate the transporting, nonequilibrium electrons to various locations on anode 80 (such as concentrating toward the center, or concentrating toward the edges, as examples).
[0062] Preferably, anode 80 is at least partially transparent to wavelengths of radiation that can excite the non-equilibrium electrons of cathode 70 to emit. For example, in some embodiments, it is thought that the non-equilibrium electrons have a work function of from about 2 to about 2½ electron volts. Correspondingly, anode 80 in such an embodiment is able to transmit light in the visible spectrum, such as from about 500 nm to about 600 nm.
[0063] In some embodiments, it is envisioned that radiation falls incident upon the surface of cathode 70 that is arranged opposite to a receiving surface of anode 80 , and radiation is received upon the cathode after the radiation passes through the anode. However, in yet other embodiments, it is contemplated that the source of radiation can be located within interior 67 , such as a radiation source supported by separating member 66 , and provided with an external source of excitation. For example, the external source of excitation can be a voltage that stimulates a light source placed within interior volume 67 , whereas in other embodiments, the excitation is an external source of light that is provided by way of fiber-optic cable into interior 67 . Still further, in some embodiments, separating member 66 is chosen to be substantially transparent to the source of radiation, such that the radiation can be located somewhat laterally to device 60 (with reference to FIG. 3B ).
[0064] In some embodiments, heat exchanger 60 includes a voltage source 94 that maintains a predetermined electrical potential between anode 80 and cathode 70 . In some embodiments, voltage source 94 is a battery. In yet other embodiments, voltage source 94 is a source of variable DC voltage. In still other embodiments, voltage source 94 provides a variable DC voltage that can be modulated based on measured parameters, such as the amount of radiation is falling incident on cathode 70 (such as would be measured by a photometer), the temperature of the cathode or anode (such as would be measured by a thermocouple), by the temperature of the structure being heated or cooled (such as by thermocouple), or some parameter associated with the operation of the product being heated or cooled by heat exchanger 60 .
[0065] FIG. 3C is a schematic depiction of a heat exchanger 160 in operation. Heat exchanger 160 is located within a panel 16 . Panel 16 and heat exchanger 160 coact to generally separate a cathode side ambient 12 from and anode side ambient 14 . The curved arrows of FIG. 3C depict the convection of a gas (such as air) that impinges upon the outer surface of cathode 170 . Likewise, the curved arrows of FIG. 3C further depict the convection of a gas (such as air) that impinges upon the outer surface of anode 180 . For purposes of clarity, FIG. 3C does not include depiction of a source of electrical voltage, nor does it depiction connection of the cathode to an electrical ground.
[0066] FIG. 3C shows radiation 10 falling incident upon the outer surface of anode 180 , passing through the anode, and being received on the inner surface of cathode 170 . As this energy (for the case of visible light, photons) strikes a non-equilibrium electron 174 , that electron is emitted from cathode 170 and transports through internal gap 167 and is received by anode 180 . This nonequilibrium electron 174 , which was hotter than its surrounding carbon lattice of cathode 170 , carries this heat from cathode 170 to anode 180 . As a result, the overall energy (and overall bulk temperature) of cathode 170 is reduced and cathode 170 becomes cooler. Likewise, this transfer of heat by way of electron 174 causes an increase in the thermal energy of anode 180 , with a subsequent increase in the temperature of anode 180 .
[0067] As a result of radiation 10 falling incident upon cathode 170 , cathode 170 becomes cooler. The cathode side convective currents 12 provide heat from cathode side ambient conditions into the cathode, with subsequent cooling of the cathode side ambient. This heat is likewise transferred to the anode side ambient conditions by way of anode side convective currents 14 .
[0068] FIG. 3D is a schematic representation of a heat exchanger 260 according to another embodiment of the present disclosure. Heat exchanger 260 includes a cathode 270 that is substantially transparent to the wavelengths of radiation that can excite electrons 274 to emit. FIG. 3D shows radiation 10 falling incident upon the outer surface of cathode 270 , through which radiation 10 is received by the nonequilibrium electrons 274 . These electrons emit and transport through 267 to anode 280 .
[0069] The heat received by the anode can be removed in any manner. As shown in FIG. 3D , heat from anode 280 is conducted into the working fluid 291 of the flow path of an anode side heat exchanger 290 . The hotter working fluid 291 exiting toward the left of FIG. 3D is received within a structure (not shown) that dumps the heat to anode side ambient conditions. In some embodiments, the working fluid 291 is actively pumped through a 2nd heat exchanging loop (heat exchanger 260 being the 1st heat exchanger). In some embodiments, the working fluid 291 can contain nanoparticles to further enhance the pickup of heat from anode 280 , and may be pumped actively (such as by a pump, electromagnetically, or electrophoretically, as examples), or by passive convection within heat exchanger 290 .
[0070] FIG. 3E shows a heat exchanger 360 in yet another embodiment of the present disclosure. Heat exchanger 360 is arranged similarly to that of heat exchanger 60 in FIG. 3B , but includes a 2nd heat exchanging loop 390 that includes a working fluid 391 that provides heat to cathode 370 (which is the same as to say that working fluid 391 is cooled by cathode 370 ).
[0071] FIG. 4 is shows a heat exchanger 660 according to another embodiment of the present disclosure heat exchanger 660 includes a 1st heat exchanger similar to that shown in FIG. 3-D . Radiation 10 falls incident upon the outer surface of cathode 670 and excites nonequilibrium electrons 674 to transfer heat to anode 680 . This heat is further transferred in one embodiment by conduction through an electrical isolating substrate 697 into a thermal electric generator 696 . Generator 696 provides electrical power (as represented by the symbology in FIG. 4 ) in response to being heated. This electrical power, provided to the positive and negative contacts of generator 696 , can be used in any manner. In some embodiments, this electrical power is used to assist in the flow of heat into cathode 670 , or into the flow of heat out of anode 680 . It is further appreciated that generator 696 can be cooled by contact with anode side ambient conditions 14 .
[0072] FIG. 5A shows a heat exchanger 460 that includes means for 92 for concentrating radiation upon cathode 470 . For those embodiments in which radiation is received through the anode side, a micro lens array 492 receives radiation 10 from a source and concentrates that radiation into a pattern 10 ′ upon the inner surface of cathode 470 . This concentrated pattern 10 ′ likewise provides electrons 474 that are emitted toward cathode 480 , with subsequent heating of cathode 480 . Cooling of the anode side can be accomplished in any manner, including the passage of a fluid between micro lens 492 A and anode 480 .
[0073] In some embodiments, cathode 470 is adapted and configured to include distinct regions that are intercalated with the substance (or relatively intercalated more with the substance than surrounding regions), and these distinct regions receive the concentrated radiation pattern 10 ′. Further, although micro lens 492 has been shown substantially planar, it is recognized that various configurations of micro lens arrays are contemplated, including curved arrays with larger surface areas for receipt of radiation. Further, it is understood that one or more micro lenses can be incorporated into separating member 466 .
[0074] FIG. 5B shows a heat exchanger assembly 560 in which the anode, cathode, and separating member are received within a curved it is radiation reflector, such as a parabolic mirror 592 B. Radiation received upon the inner surface of reflector 592 B is reflected through anode 580 and on to cathode 570 . It is appreciated that in any of these embodiments described, of that radiation can be received through the anode or through the cathode.
[0075] X1. One aspect of the present disclosure pertains to an apparatus for transferring heat activated by radiation. The method preferably includes a cathode comprising a substrate of graphite, the graphite being intercalated with an alkali metal, the cathode graphite having a plurality of electrons that are not in thermal equilibrium with the cathode graphite lattice, said cathode having opposing inner and outer surfaces. The apparatus preferably includes an anode comprising a substrate of graphite, wherein substantially all of the electrons of the anode graphite are in thermal equilibrium with the anode graphite lattice, said anode having opposing inner and outer surfaces. The apparatus preferably includes a member maintaining a gap between said cathode inner surface and said anode inner surface, said member being substantially non-conductive of electricity, wherein the transfer of from said cathode to said anode is activated by reception of the radiation on said cathode.
[0076] Yet other embodiments pertain to any of the previous statements X1 which are combined with one or more of the following other aspects:
[0077] Wherein the substrate of graphite of the cathode includes a plurality of graphene petals and/or the substrate of graphite of the cathode includes a plurality of carbon nanotubes.
[0078] Wherein the alkali metal is potassium.
[0079] Wherein the intercalated alkali metal lowers the work function of the non-equilibrium electrons and/or the non-equilibrium electrons have a work function that is less than about 3 electronvolts.
[0080] Wherein the non-equilibrium electrons have a work function within a range of electron voltages, and the radiation is within a spectrum of wavelengths corresponding to the range of electron voltages.
[0081] Wherein the work function is less than about 3 electronvolts and the spectrum includes radiation from about five hundred to about six hundred nanometers.
[0082] Wherein the reception of radiation causes the non-equilibrium electrons to be emitted from said cathode, and said cathode is adapted and configured such that the non-equilibrium electrons are emitted from the inner surface of said cathode and toward the inner surface of said anode.
[0083] Wherein said cathode becomes cooler and said anode becomes hotter.
[0084] Wherein the source of radiation is the sun, and/or which further comprises a source of radiation, and/or wherein the source is a laser.
[0085] Wherein said cathode, said anode, and said member combine to form an interior volume that is coextensive with the gap, and the interior volume is substantially void of matter.
[0086] Wherein said anode is at least partially transparent to the radiation, and radiation incident upon the outer surface of said anode is transmitted through said anode and is received on the inner surface of said cathode.
[0087] Which further comprises means for removing heat from said anode and/or which further comprises means for adding heat to said cathode.
[0088] Which further comprises a source of electrical potential, said source being in electrical communication with said anode and said cathode, said source establishing an electrical potential between said anode and said cathode.
[0089] Wherein said source is a source of variable electrical potential.
[0090] While the disclosures have been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only certain embodiments have been shown and described and that all changes and modifications that come within the spirit of the disclosure are desired to be protected. | This disclosure presents the use of electrons as the ‘working fluid’ in conjunction with a solid nanomaterial that hinders electron coupling to the atomic lattice of the nanomaterial, i.e., they are out of equilibrium. The electrons can achieve very high effective temperatures with minimal heating of the solid lattice. These ‘hot’ electrons emit from the absorbing material, carrying both the light energy and energy acquired from the atomic lattice. Thus, the operation of this disclosure includes shining light on an object to make the object cool instead of heat. It is envisioned that one of ordinary skill in the art would find the operation quite counter-intuitive. | 2 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims the priority of European patent application No. 00 109 302.0, filed Apr. 29, 2000, the disclosure of which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
The present invention concerns primers for the improvement of the adhesion of plastics that are difficult to bond or seal, in particular of polyolefinic thermoplastics with one component or two component adhesive systems.
BACKGROUND OF THE INVENTION
Primers, also referred to as activators or adhesion promoters, are applied where the used adhesive does not achieve any, or only limited, adhesion to the substrate. Thereby, the adhesive system consisting of pre-treatment (primer) and adhesive are adapted to each other and to the substrate. Such primers can be physically hardening or chemically cross-linking. Pre-treatment (primer) systems for plastics such as e.g. polypropylene, polyethylene, EPDM (ethylene propylene diene terpolymers), polyamide, ABS (acrylonitrile butadiene styrene copolymers) etc., or anti-scratch treated plastics, such as e.g. polydimethylsiloxane coated polycarbonate, are known and described in patent documents.
According to EP 0 409 198, after the application of a primer comprising silyl-functionalized fumarates, the polyolefin must be attached thereto by (partial) melting.
In WO 92/09669 polyolefine primers are disclosed that comprise ethylene diamine derivatives and that in particular are suitable for cyanoacrylate adhesives.
EP 0 295 930 discloses a primer comprising diazobicyclo compounds or triazabicyclo compounds suitable for cyanoacrylate adhesives. Said primer does not form a film and therefore only results in a minor improvement of the adhesion; furthermore, said primer is unsuitable for adhesives that are less rigid then cyanoacrylate adhesives.
In EP 0 703 285 a mixture consisting of chlorinated polyolefin and flexibilized epoxy resin is disclosed as primer for polyolefins. Since said primer is not cross-linking, its heat stability is insufficient. The epoxy resin furthermore has a low affinity to polyolefins. In addition, the presence of chlorine is critical in view of legal regulations.
In the patent documents JP 3 239 761 or JP 62 095 326, respectively, reaction products of hydrogenated polybutenediol with polyisocyanates are desdribed. The low solubility of the hydrogenated polybutadiendiol in a solvent, however, affects the productivity, and because of separation and gel formation the storage stability is limited.
BRIEF SUMMARY OF THE INVENTION
Hence, it is a general object of the invention to provide a primer for the improvement of the adhesion between polyolefinic plastics and adhesives or sealants, respectively, that overcomes the above described disadvantages.
Said goal has been achieved by providing a primer comprising a polyol provided with reactive terminal groups, whereby said polyol comprises hydrogenated polyisoprenediol.
DETAILED DESCRIPTION OF THE INVENTION
Such primer contains or consists of a pre-polymer that is based on a polyol provided with reactive terminal groups, whereby said polyol contains or consists of a hydrogenated polyisoprenediol. Preferred reactive terminal groups are isocyanate groups or silane groups.
For specific applications, and in order to enhance the storage stability, the reactive terminal groups may be protected, such that they gain their reactivity after performed deprotection or deblocking, respectively, e.g. due to heat application.
Preferred primers comprise the pre-polymer together with a suitable solvent.
The inventive primer has good affinity to appolar plastics, in particular to polyolefinic thermoplastic substrates such as polyethylene, polypropylene, polyvinylchloride, ABS or EPDM. Because of the chemical cross-linking and film-forming characteristics it is heat resistant, does not comprise any components that together with the adhesive could initiate a degrading reaction, and shows very good wetting to different substrates as well as excellent potlife. Furthermore, it is possible to produce a solvent and pre-polymer comprising primer by a simple method, since the pre-polymer that is based on hydrogenated polyisoprenediol (=HPIPOL) is very well soluble in aromatic or non-aromatic solvents in high concentrations at room temperature. This leads, on the one hand to an improved productivity and, on the other hand, because of the good compatibility and reduced tendency to separate, to an improvement of the storage stability. Furthermore, the good solubility of the HPIPOL allows a high solid content in the inventive primer and effects goos homogeneous film characteristics with good quality of the adhesion. Non-homogeneous films with differing thickness lead to a reduced and insufficiently reproducible quality of the adhesion.
The inventive primer is based on humidity curable binders that are obtained by reaction of the HPIPOL (see above) with a compound that comprises at least one OH-reactive group and at least one further reactive group, whereby the at least one further reactive group either directly represents the reactive terminal group of the pre-polymer, or a group that in a further step can be transferred into said reactive terminal group.
A preferred binder is obtained through reaction of the HPIPOL with a polyisocyanate, whereby the ratio of OH:NCO is between 1:2 and 1:10, preferably between 1:2.5 and 1:3.5. Corresponding ratios are also suitable or preferred, respectively, for the production of a respective silane-terminated pre-polymer. Such prepolymers are preferably incorporated into a non-polar aliphatic or aromatic solvent, such as e.g. cyclohexane, xylene etc., or in solvent mixtures, such as e.g. ethylacetate and heptane, in a concentration of 0.5 to 50% by weight, in particular of 5 to 15% by weight.
Possible polyisocyanates are 4,4′-diphenylmethane diisocyanate (MDI), 2,4-toluene diisocyanate, isophorone diisocyanate, hexamethylene-diisocyanate, tri(phenylisocyanate)thiophosphate, triphenylmethane-4,4′,4″-triisocyanate etc., or mixtures thereof.
The reaction of the polyol with the polyisocyanate takes place in known manner under nitrogen and stirring at optionally enhanced temperature and optionally in the presence of a catalyst, whereby the ratio OH:NCO is between 1:2 to 1:10, preferably between 1:2.5 to 1:3.5. The polyol, prior to said reaction, is homogenized in the solvent.
In a further step, the isocyanate groups of the prepolymer can be transferred either by means of aminosilane or mercapto-silane at least partially and preferably entirely into a humidity reactive silane groups terminated prepolymer, or with hydroxyethyl(meth)acrylate in an acrylate group terminated prepolymer, the double bonds of which are e.g. radically cross-linking in the presence of an initiator.
For example, the HPIPOL can be reacted with isophorone diisocyanate (IPDI) or toluene diisocyanate (TDI) to isocyanate terminated pre-polymer and said polymer—if desired—can then be reacted with aminosilane or mercaptosilane to a silane group terminated pre-polymer.
It is of course also possible to directly insert the silane-endgroup by choosing a suitable compound. For example HPIPOL can be reacted with isocyanatopropyltrimethoxysilane.
The polyol, HPIPOL, necessarily present in the pre-polymer used according to the invention, can be mixed with other polyols such as e.g. polyethers, polyesters, or other hydroxygroups functionalised hydrocarbons, whereby the amount of HPIPOL referred to the whole polyol should at least be 10% by weight, preferably at least 40% by weight. By using mixtures, the film forming characteristics of the primers of the present invention to each substrate can be optimized. Such polyol mixtures can be obtained by mixing the polyols and then introduction of the reactive end groups, or by mixing of prepolymers from different polyols.
Investigations have shown that HPIPOL, mixed with e.g., a hydrogenated polybutadiene-diol(HPBDOL) in a ratio of 1:0.1 to 1:3, in particular in a ratio of 1:0.3 to 1:1 results in a very good binder or primer, respectively. Thereby, conflicting characteristics can be very good balanced. For example, on the one hand an economic production (no melting of large amounts of solid polyols) and, because of low separation tendency, a good storage stability are obtained. On the other hand, an optimal potlife that guarantees a good wetting or surface penetration, respectively, of the inventive primer is provided whereby nevertheless a dry film formation in short time is achieved.
Primers with high solid content of HPBDOL (e.g. >10% by weight HPBDOL/MDI in xylene), because of the separation tendency during the drying time, result in a film with non-homogeneous characteristics such as different thickness, leading to a reduced and varying adhesion quality.
The dry film formation is a necessity for the application of either, according to the respective need, a further primer or the adhesive.
The primer can be applied to a substrate by methods such as dipping, spraying and painting. It is also within the scope of the present invention that the substrate treated with the primer is subjected to enhanced temperature or enhanced humidity or to both, enhanced temperature and enhanced humidity.
Below some examples (see table below) are shown that further illustrate the invention, that, however, shall not restrict the scope of the invention in any way. The primers according to the invention, examples 1, 2 and 3, are easily producible, storage stable, they have good adhesion performance and they are stable in hot (70° C.) and wet (relative humidity 100%) conditions.
The solubility of the HPBDOL/MDI in reference 4 and the end of the HPIPOL/MDI (inventive example 2) is clearly different. While HPBDOL/MDI can only be dissolved in an aromatic solvent, but not in an aliphatic solvent, such as e.g. a mixture consisting of cyclohexane and ethylacetate (leads to separation), HPIPOL/MDI, without any problems, can be dissolved in aromatic and aliphatic solvents and solvent mixtures.
From the state of the art, it is known that HPBDOL/MDI is only well soluble in an aromatic solvent such as xylene up to an amount of at most 10% by weight. At >10% by weight separation tendency or the danger of gelling (pudding formation, see reference 2) exists.
The pre-polymer HPIPOL/MDI used according to the present invention is soluble in amounts of over 90% by weight, preferably in an aromatic solvent, such as xylene. HPIPOL/MDI is also soluble in aliphatic solvents, such as preferably a mixtures of cyclohexane and ethylacetate in concentrations of >20% by weight. The adhesion quality is practically not influenced by the kind of the solvent used, whether aromatic or aliphatic, the more so since the solvent, after application, evaporates in short time. In the following table PL means potlife and TSR means combined tension and shear resistance.
While there are shown and described presently preferred embodiments of the invention, it is to be distinctly understood that the invention is not limited thereto but may be otherwise variously embodied and practiced within the scope of the following claims.
Reference 2
Reference 4
Reference 5
Parameter
Reference 1
JP62095326
Reference 3
JP62095326
EP0703285
Ex. 1
Ex. 2
Ex. 3
Epoxy-Poly BD (MW = 1800/Epoxy = 460) (Elf
0
0
0
10
0
0
0
(Atochem)
Chlorinated Polyolefin (Eastman Chemical)
no pretreat-
0
20
0
10
0
0
0
ment
HPIPOL (OH-number = 0.9 meq/g)
0
0
0
20
10
7
HPBDOL (OH-number = 0.8 meq/g)
20
0
10
0
0
0
3
MDI (Bayer)
8
0
4
0
8
4
4
Xylene
pure PP
72
80
86
80
72
86
86
Total [g]
100
100
100
100
100
100
100
Production
—
gelled
critical
critical
critical
very
very
good
(critical = bad solubility characteristics)
(pudding)
good
good
Storage Stability
—
not o.k.
good
critical (se-
good
good
good
good
paration)
PL (≈50 μm film dryness at 20° C. examined
—
—
≈5 min.
≈5 min.
≈20 min.
≈20
≈15
≈10
with finger)
min.
min.
min.
Adhesion with Sika-2K PUR (MG2K) on PP
no adhesion
—
good
good
bad
good
good
good
TSR (25 × 10 mm/d = 0.5 mm) [MPa]
(≈2.8)
(>3)
(<0.1)
(>3)
(>3)
(>3)
Adhesion with Sika-2K Acrylate on PP
no adhesion
—
medium
good
bad
good
good
good
TSR (25 × 10 mm/d = 0.5 mm/100 mm/min.)
(≈1.5)
(≈3)
(<0.1)
(>3)
(>3)
(>3)
[MPa]
Adhesion (additionally SikaPrimer209) with Sika-
no adhesion
—
medium
good
bad
good
good
good
flex255 on PP
(<1)
(≈3)
(<0.1)
(≈3)
(≈3)
(≈3)
TSR (25 × 10 mm/d = 3 mm/100 mm/min.)
[MPa]
Heat Restance (80° C.)
—
—
bad
good
bad
good
good
good | New primers for the improvement of the adhesion of cross-linking adhesive systems top polyolefinic thermoplastic materials such as e.g., polypropylene, polyethylene or EPDM are disclosed. Said primers, on the one hand are characterized by a simple method of production and good storage stability, on the other hand by good wetting and good homogeneous film forming characteristics, said film forming characteristics enabling a uniform thickness of the layer, leading to good adhesion qualities. Essential constituents of such primers are prepolymers based on hydrogenated polyisoprene diol. | 2 |
BACKGROUND
Attaching complementary fasteners, such as a nut and a bolt, to a structure is ordinarily a simple, one-person job. Situations may arise, however, when the structure is of such size and/or shape that a single person is not able to simultaneously access both fasteners. For example, attaching a nut and a bolt through a hole in the trunk floor of an automobile requires two people to accomplish—one to hold the screw in place while the other tightens the nut from underneath the automobile. Thus, in cases such as this, the otherwise simple, one-person task of fastening a nut and a bolt to structure becomes a two-person job. Moreover, this is undesirable from the standpoint of workman productivity and efficiency.
United States Publication No. 2005/0155211 by Powell discloses a magnetic bolt holder which has a hexagonal recess for securing a nut or a bolt to a ferrous structure. The Powell device is an insufficient solution to the above-stated problem for a number of reasons. First, the device is designed for a specific size and shape of fastener (e.g., a ¼″ hex nut). Thus, a consumer would be required to purchase a different size/shape of the Powell device for each size fastener being used. Moreover, the magnetic surface of the device is substantially coplanar. The effectiveness of the device is therefore severely diminished, if not eliminated, when used on any non-flat surface.
Thus, conventional tools do not provide for a customizable solution to the above problem. Conventional tools also do not provide a solution that is adaptable for use with uneven surfaces.
SUMMARY
This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.
Described herein is technology for, among other things, a tool for assisting the attachment or removal of a first fastener and a second fastener to or from a structure. The tool includes a lower portion adapted to magnetically attach to a surface of the structure. The tool also includes an upper portion configured to be spaced a distance from the surface of the structure when the lower portion is magnetically attached to the surface of the structure. The upper portion also includes a holder extending therefrom and adapted to hold the first fastener. The holder is biased to urge the first fastener in a direction of the surface of the structure.
Also described herein is technology for, among other things, a tool for assisting the attachment or removal of a first fastener and a second fastener to or from a structure. The tool includes a main body having a holder extending therefrom. The tool also includes adjustable feet adjustably coupled to the main body and adapted to magnetically attach to a surface of the structure. The holder is biased to urge the first fastener in a direction of the surface of the structure.
Also described herein is technology for, among other things, a tool system for assisting the attachment or removal of a first fastener and a second fastener to or from a structure. The tool system includes a drive bit adapted to mate with the first fastener and a magnetic fastener holder. The magnetic fastener holder includes a lower portion adapted to magnetically attach to a surface of the structure. The magnetic fastener holder also includes an upper portion configured to be spaced a distance from the surface of the structure when the lower portion is magnetically attached to the surface of the structure. The upper portion of the magnetic fastener holder includes a drive bit holder extending therefrom, which is adapted to received the drive bit. The drive bit holder is also biased to urge the drive bit and the first fastener in a direction of the surface of the structure.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of embodiments of the invention:
FIG. 1A is a top-perspective view of a magnetic fastener holder, in accordance with an embodiment of the present invention;
FIG. 1B is a bottom-perspective view of the magnetic fastener holder of FIG. 1A ;
FIG. 1C is a side view of the magnetic fastener holder of FIG. 1A ;
FIG. 1D is a front view of the magnetic fastener holder of FIG. 1A ; and
FIG. 1E is a top view of the magnetic fastener holder of FIG. 1A .
DETAILED DESCRIPTION
Reference will now be made in detail to the preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. While the invention will be described in conjunction with the preferred embodiments, it will be understood that they are not intended to limit the invention to these embodiments. On the contrary, the invention is intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope of the invention as defined by the claims. Furthermore, in the detailed description of the present invention, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be obvious to one of ordinary skill in the art that the present invention may be practiced without these specific details. In other instances, well known methods, procedures, and components have not been described in detail so as not to unnecessarily obscure aspects of the present invention.
Generally speaking, embodiments provide for a magnetic fastener holder that is adapted to securely hold a first fastener in place, relative to a surface of structure, so that a second fastener may be attached to the first fastener from a second surface of the structure. For example, a user may place a screw into a correspondingly sized hole in the structure. The user may then position the magnetic fastener holder over the screw to hold the screw place. The magnetic fastener holder will continue to hold the screw in place without human assistance. Thus, the user may then attach a nut, bracket, or other fastener to the other side of the screw without having to hold the screw in place himself and without the assistance of a second person.
The magnetic fastener holder may be adaptable to hold virtually any size, shape, or type of fastener in place. In one embodiment, this is achieved using an interchangeable drive bit system. In one embodiment, the magnetic fastener holder is adjustable to enable it to be attached to uneven surfaces in addition to typical flat surfaces.
Referring to FIGS. 1A-1E , various views of a tool 100 , in accordance with an exemplary embodiment of the present invention, are illustrated therein. Tool 100 will at times also be referred to herein as a magnetic fastener holder 100 . As shown, tool 100 has a main body 110 . The main body 110 of the exemplary, illustrated embodiment is of a substantially “U” or “C” shape. However, it will be readily appreciated by one of ordinary skill in the art that various other shapes of main body 110 may be used without departing from the spirit and scope of the present invention. For example, and not for limitation, the main body 110 may alternatively be of substantially cylindrical, pyramidal, or trapezoidal shapes.
The main body 110 includes an upper portion 112 and a lower portion 114 . The lower portion is adapted to magnetically attach to a ferrous surface of a structure. To this end, the lower portion 114 may include a plurality of magnetic feet 120 . While FIGS. 1A-1E specifically illustrate a tool 100 having four feet 120 , it should be appreciated that other embodiments are not limited as such. Moreover, while the exemplary, illustrated embodiment includes a plurality of adjustable feet 120 , a simpler, alternative embodiment may be implemented without magnetic feet 120 and recesses 118 , wherein the bottom surfaces 116 of the lower portions 114 are magnetized to enable magnetic coupling with a ferrous surface.
As shown, an exemplary foot 120 may include a vertical member 124 and a horizontal member 123 pivotally coupled together at a pivot point 122 . The vertical member 124 is disposed within a corresponding recess 118 of the lower portion 114 of the tool 100 and is slidably coupled with the lower portion 114 via fasteners 125 and 126 and through respective grooves 127 and 119 . The horizontal member 123 of the foot 120 also includes a magnetic portion 121 for magnetically coupling with a ferrous surface.
As shown, the feet 120 of the exemplary, illustrated embodiment are fully adjustable, enabling the tool 100 to be attached to surfaces of varying contours. For example, each foot 120 may be independently adjusted to different lengths by adjusting the foot 120 to different locations within recesses 118 . Moreover, the angles of the horizontal members 123 of the feet 120 , relative to the vertical members 124 , may be adjusted to varying angles by rotating the horizontal members 123 about the pivot points 122 .
The upper portion 112 of the main body 110 has coupled thereto a fastener holder assembly 130 . Assembly 130 includes a drive bit holder 134 , which is adapted to receive a conventional drive bit 132 , such as a conventional ¼″ hex or square drive bit. The drive bit 132 may be any of a variety of different types of drive bits, including but not limited to a Phillips-head bit, a flat-head screwdriver bit, a hex bit, a torx bit, a square Robertsons bit, a nut setter, and a socket adapter. Thus, because of the interchangeability with the various types of conventional drive bits, the tool 100 is configurable for use with a variety of different sizes and shapes of fasteners.
The assembly 130 also includes a spring 136 , or other functionally equivalent device, that is disposed between the upper portion 112 of the main body 110 and the drive hit holder 134 . The spring 136 is adapted to urge the drive bit holder 134 , the drive bit 132 , and any first fastener in communication therewith in the direction of the surface of the structure to which the tool 100 is attached. Thus, not only-does the tool 100 initially apply a positive force to the first fastener, but the tool 100 also continues to apply a positive force to the first fastener as the first fastener is secured to a second fastener and thereby potentially drawn away from the upper portion 112 and towards the surface of the structure. An upper shaft 137 of the assembly 130 passes through an aperture in the upper portion 112 of the main body 110 and is secured via fastener 138 . Thus, during use, the upper shaft 137 is allowed to slide longitudinally between a first position (defined by the bottom surface of fastener 138 ) and a second position (defined by the upper surface of drive bit holder 134 and the maximum compression of spring 136 ).
In one embodiment, the assembly 130 is coupled with the upper portion 112 of the main body 110 such that the assembly, and therefore the first fastener in communication therewith, are prevented from rotating when the first fastener is being fastened to the second fastener. It should be appreciated that this may be achieved in a number of ways. For example, the upper shaft 137 may have a non-circular cross-section, such as a triangle, a square, a hexagon, a star, or the like. In order to prevent assembly 130 from rotating, the aperture in the upper portion 112 through which the upper shaft 137 passes may be sized and shaped similar to the upper shaft 137 , to enable upper shaft 137 to freely slide through the aperture while at the same time being prevented from rotating therein. For example, if upper shaft 137 has a ¼″ hexagonal cross-section, a ¼″ (or slightly larger) hexagonal aperture through the upper portion 112 would allow the upper shaft 137 to slide therethrough, but it would not allow the upper shaft 137 to rotate therein.
Thus, the present disclosure provides for a tool that serves as “third hand” in applications requiring two fasteners to be joined together through a structure that prevents a workman from accessing both fasteners at the same time. The tool accordingly may be used to hold one of the two fasteners in place while the workman attaches the other. Additionally, various embodiments advantageously provide a tool that is adjustable to enable attachment to different surfaces of varying contours. Various embodiments are also advantageously adaptable to be used in conjunction with various different types and sizes of fasteners. Thus, a workman is not required to have a different fastener holder tool for each different fastener. Rather, such embodiments may work in conjunction with convention drive bits, which may be used for altogether separate purposes and which the workman already likely owns.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein. | Described herein is technology for, among other things, a tool for assisting the attachment or removal of a first fastener and a second fastener to or from a structure. The tool includes a lower portion adapted to magnetically attach to a surface of the structure. The tool also includes an upper portion configured to be spaced a distance from the surface of the structure when the lower portion is magnetically attached to the surface of the structure. The upper portion also includes a holder extending therefrom and adapted to hold the first fastener. The holder is biased to urge the first fastener in a direction of the surface of the structure. | 1 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] Not Applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable
Description of Attached Appendix
[0003] Not Applicable
BACKGROUND OF THE INVENTION
[0004] This invention relates generally to the field of snowboarding and more specifically to Angularly Adjustable Mechanism for Snowboard Bindings. Snowboard binding systems generally use a toothed disk bolted directly to the snowboard whereas the disk mates with a toothed recess in the boot binding. Altering the angular orientation is a time-consuming trial and error process necessitating disassembly and reassembly to eventually arrive -at a satisfactory alignment. However, a snowboarder may not use the same boot orientation for all snow surfaces. Half-pipes, slaloms, and downhill runs all might lend themselves to differing stances primarily the angular orientation of the bindings to the longitudinal axis of the snowboard.
[0005] In addition to the desirability of changing the angular orientation of the bindings to accommodate riding the snowboard over varying terrain, the bottom of the slope provides another opportunity for changing binding orientation. Typically after a downhill run, the snowboard rider will unbuckle one boot to propel himself or herself forward much like a skateboarder with the other boot still bound to the board. Unlike normal riding where the longitudinal axis of the snowboard is aligned side-to-side with feet and hips, during level-ground locomotion, the snowboard is aligned front-to-rear, with the boot still bound at a nearly perpendicular angle to what is anatomically comfortable. In addition to being very uncomfortable, it can lead to or exacerbate strains and other maladies in the leg. Using an Angularly Adjustable Mechanism for Snowboard Bindings, the rider in this situation can orient the boot still bound with the longitudinal axis of the snowboard and travel more easily and with greater comfort and safety, especially when mounting and dismounting the chair lift.
[0006] Prior devices have been invented for snowboard binding adjustment as described in the following patents:
U.S Pat. No. Patentee Issue Date 5,941,552 Beran Aug. 24, 1999 5,947,488 Gorza Sep. 7, 1999 5,028,068 Donovan Jul. 2, 1991 5,897,128 McKenzie Apr. 27, 1999 6,206,402 Tanaka Mar. 27, 2001 5,782,476 Fardie Jul. 21, 1998 5,667,237 Lauer Sep. 16, 1997 5,586,779 Dawes Dec. 24, 1996 6,318,749 Eglitis Nov. 20, 2001 6,022,040 Buzbee Feb. 8, 2000
[0007] The prior patents: U.S. Pat. No. 5,941,552 Adjustable Snowboard Binding Apparatus and Method, U.S. Pat. No. 5,947,488 Angular Adjustment Device, Particularly for a Snowboard Binding, U.S. Pat. No. 5,028,068 Quick-Action Adjustable Snow Boot Binding Mounting, U.S. Pat. No. 5,897,128 Pivotally Adjustable Binding For Snowboards, U.S. Pat. No. 6,206,402 Snowboard Binding Adjustment Mechanism, U.S. Pat. No. 5,782,476 Snowboard Binding Mechanism, U.S. Pat. No. 5,667,237 Rotary Locking Feature For Snowboard Binding, U.S. Pat. No. 5,586,779 Adjustable Snowboard Boot Binding Apparatus, and U.S. Pat. No. 6,318,749 Angularly Adjustable Snowboard Binding Mount all require a lever to lock and unlock angular adjustment device.
[0008] U.S. Pat. No. 6,022,040 Freely Rotating Step-In Snowboard Binding provides no means of locking the binding's swiveling device. A rider employing a snowboard equipped with this device would have far less control over the snowboard than a rigidly secured binding.
[0009] Unlike prior inventions, the Angular Adjustment Mechanism for Snowboard Bindings positioned between the snowboard and boot binding allows angular adjustment between the snowboard rider's boot bindings and the snowboard without the need for any tools or levers. The user can make adjustments at any time by weighting the board with either foot and lifting and rotating the opposite foot. A lifting action releases the mechanism allowing for the adjustment of angular orientation. Removal of the lifting force engages the locking mechanism preventing further angular movement.
BRIEF SUMMARY OF THE INVENTION
[0010] The primary object of the invention is the convenience of adjusting the angular orientation of the snowboard bindings easily at any time, even while in motion. Another object of the invention is no external levers or tools to perform the adjustment of binding orientation. Another object of the invention is no unintended angular motion. Another object of the invention is a device that is unaffected by board torsion. A further object of the invention is to use existing bolt holes on snowboards and boot bindings to allow a retrofit of conventional boards and bindings currently on the market.
[0011] In accordance with a preferred embodiment of the invention, there is disclosed an Angular Adjustment Mechanism for Snowboard Bindings comprising: upper plate, upper gear coupling, wave washer, upper retainer, lower retainer, and lower gear coupling.
[0012] Other objects and advantages of the present invention will become apparent from the following descriptions, taken in connection with the accompanying drawings, wherein, by way of illustration and example, an embodiment of the present invention is disclosed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The drawings constitute a part of this specification and include exemplary embodiments to the invention, which may be embodied in various forms. It is to be understood that in some instances various aspects of the invention may be shown exaggerated or enlarged to facilitate an understanding of the invention.
[0014] FIG. 1 a is an exploded view showing the position of the invention relative to the snowboard and boot binding.
[0015] FIG. 1 b is a perspective view of the portions of the invention which mate with the snowboard and boot binding.
[0016] FIG. 2 a is an exploded view of the invention.
[0017] FIG. 2 b is a side view of the assembled invention.
[0018] FIG. 3 a is a cross sectional side view of the invention in its engaged configuration.
[0019] FIG. 3 b is a cross sectional side view of the invention in its disengaged configuration.
[0020] FIG. 4 a and FIG. 4 b are perspective views of the invention illustrating its use.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] Detailed descriptions of the preferred embodiment are provided herein. It is to be understood, however, that the present invention may be embodied in various forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but rather as a basis for the claims and as a representative basis for teaching one skilled in the art to employ the present invention in virtually any appropriately detailed system, structure or manner.
[0022] In accordance with the present invention, FIG. 1 a shows the position of Angular Adjustment Mechanism for Snowboard Bindings 10 in an exploded position relative to both boot binding 20 and section of snowboard 40 . Those portions of the invention which mate rigidly to either the snowboard 40 or the boot binding 20 are shown in FIG. 1 b . Referencing both FIGS. 1 a and 1 b , upper plate 11 and upper gear coupling 12 are shown with a bolt hole pattern matching that of boot binding 20 and, when incorporated, would mate rigidly to same. Lower retainer 16 and lower gear coupling 15 are shown with a bolt hole pattern matching that of snowboard 40 and, when incorporated, would mate rigidly to same. The components shown in use in Angular Adjustment Mechanism for Snowboard Bindings 10 in all figures are shown substantially thicker than necessary for purposes of clarity of illustration and can therefore be reduced in size for manufacturing.
[0023] FIG. 2 a shows an exploded view of the Angular Adjustment Mechanism for Snowboard Bindings 10 . Upper plate 11 and upper gear coupling 12 both mount rigidly to boot binding using bolts or similar fasteners (not shown). Lower retainer 16 and lower gear coupling 15 , both mount rigidly to snowboard using bolts or similar fasteners (not shown). The upper retainer 13 features a lip at its top with bolt holes for affixing to upper plate 11 using bolts or similar fasteners (not shown). Inside the upper retainer 13 , at its bottom is a lip extending inwards. The lower retainer 16 features a lip at its top extending outwards. When assembled, the lower lip of upper retainer 13 is below the upper lip of lower retainer 16 which prevents a detachment of upper retainer 13 and lower retainer 16 and provides an annular cavity between these two features. Within this cavity is positioned wave washer 14 . Wave washer 14 provides a tension force that drives the combination of upper gear coupling 12 and lower gear coupling 15 together which locks the mechanism from rotating when external forces are absent.
[0024] Wave washer 14 is an undulating ring of spring steel that provides a resistive opposition to compression forces. Washers of differing stiffness or a plurality of washers could be made available to fit the user's preferences. Alternative components might include belleville washers, compression springs, or elastomers.
[0025] Upper plate 11 and upper gear coupling 12 are shown as separate items but can be constructed as one piece. Furthermore, lower retainer 16 and and lower gear coupling 15 are shown as separate items but can be constructed as one piece.
[0026] Upper gear coupling 12 and lower gear coupling 15 are plates with one side comprised of radially-extending raised teeth. When upper gear coupling 12 and lower gear coupling 15 are engaged (teeth of one extended into the recesses of the other), radial forces from the rider can be transmitted to the snowboard. Upper gear coupling 12 and lower gear coupling 15 are shown with a coarse tooth spacing for clarity of illustration, but more closely-spaced teeth would provide for a wider selection of boot angular orientation.
[0027] FIG. 2 b shows a side view of the mechanism fully assembled. As shown, there is upper retainer 13 fastened to upper plate 11 . Also visible is lower retainer 16 .
[0028] To illustrate the principles of operation, there is shown in FIGS. 3 a and 3 b cross-sectional side views of the assembled mechanism. Upper plate 11 and upper gear coupling 12 are both mounted rigidly to the boot binding. Lower retainer 16 and lower gear coupling 15 are both mounted rigidly to snowboard. Upper retainer 13 would be positioned as shown surrounding lower retainer 16 . The lower lip of upper retainer 13 is a slip fit over the vertical side walls of lower retainer 16 such that relative vertical motion is allowed, but snow and grime will not pass the touching surfaces to get inside. Wave washer 14 is positioned within the cavity formed by the lower inside lip of upper retainer 13 and the upper outside lip of lower retainer 16 .
[0029] While there are no external forces on the mechanism shown in FIG. 3 a , the wave washer 14 exerts pressure upward against lower retainer 16 and simultaneously downward against upper retainer 13 . This forces the upper part of the assembly (upper plate 11 , upper gear coupling 12 , and upper retainer 13 ) down against the lower part of the assembly (lower gear coupling 15 and lower retainer 16 ), thereby forcing together into a mating relationship upper gear coupling 12 and lower gear coupling 15 , which prevents any angular rotation of the top portion with respect to the lower portion.
[0030] FIG. 3 b illustrates the mechanism when it is disengaged. When the upper portion of the assembly (upper plate 11 , upper gear coupling 12 , and upper retainer 13 ) which is attached rigidly to the boot binding is forced upward while simultaneously the lower portion of the assembly (lower gear coupling 15 and lower retainer 16 ) which is attached to the snowboard is forced downward, the resistance'to compression of the wave washer 14 is overcome. The wave washer 14 then becomes substantially flattened as the upper and lower portions of the assembly are forced apart. When the separation of the upper and lower portions of the assembly become sufficiently great, the upper gear coupling 12 and lower gear coupling 15 become disengaged and the upper portion of the assembly is free to swivel in an angular direction with respect to the lower portion.
[0031] In accordance with the present invention, FIGS. 4 a and 4 b illustrate a typical application. In these figures, the present invention Angular Adjustment Mechanism for Snowboard Bindings is mounted between the underside of boot binding 20 and the upper surface of snowboard 40 and is therefore concealed from view. In a static circumstance (no external forces applied), the Angular Adjustment Mechanism for Snowboard Bindings is locked and no angular motion is possible. To initiate intended angular repositioning, in FIG. 4 a , the snowboard rider puts his or her weight on one boot 30 (indicated in the figure by the “down” arrow). Simultaneously, the rider lifts up on the other boot (indicated in the figure by the “up” arrow) which disengages the locking feature of the Angular Adjustment Mechanism for Snowboard Bindings which permits the angular rotation of the boot 30 in any orientation desirable ( FIG. 4 b ). Relieving the opposing forces on the Angular Adjustment Mechanism for Snowboard Bindings re-engages the locking mechanism prohibiting further angular motion. The preceding steps may be repeated in the opposite order to adjust the other boot's angular orientation.
[0032] While the invention has been described in connection with a preferred embodiment, it is not intended to limit the scope of the invention to the particular form set forth, but on the contrary, it is intended to cover such alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims. | The Angular Adjustment Mechanism for Snowboard Bindings positioned between the snowboard and boot bindings allows angular adjustment between the snowboard rider's boot bindings and the snowboard without the need for any tools or levers. The user can make adjustments at any time by weighting the board with either foot and lifting and rotating the opposite foot. A lifting action releases the mechanism allowing for the adjustment of angular orientation. Removal of the lifting force engages the locking mechanism preventing further angular movement. | 0 |
FIELD OF THE INVENTION
The present invention relates to a product which can be fed to lactating ruminants to buffer and neutralize the pH of the rumen and to provide potassium, chlorine, and sodium in the diet. The invention also relates to a product which may be used to neutralize acidity in an animal gut, including the avian or human gut.
BACKGROUND OF THE INVENTION
Current ruminant feeding practices rely heavily on readily fermentable carbohydrates and chopped, ensiled forages. Such feeds generate acid in the rumen which is not counterbalanced by dietary or endogenous bases and buffers. Under acidic conditions, the population of microorganisms found in the rumen are less desirable than those found under neutral or slightly basic conditions. Under neutral or slightly basic conditions, rumen microorganisms produce more fatty acids, which can be used by the lactating animal to produce milk fat.
It is known that sodium bicarbonate and magnesium oxide, alone or in combination, are effective in increasing the milk and/or milk fat production of animals fed on high acid-producing diets. Chalupa and Kronfeld, 1983, Animal Nutrition and Health, May-June, 50; Erdman, et al. 1982, Journal of Dairy Science, 65, 712; Erdman, et al. 1980, Journal of Dairy Science, 63, 923; and Kilmer et al. 1980, Journal of Dairy Science, 63, 2026. However, these additives have the undesirable effets of temporarily reducing the feed intake and decreasing the serum levels of potassium and magnesium.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a feed supplement to improve the yield of milk fat produced by ruminants.
It is a further object of the invention to provide a feed supplement which serves to neutralize acids produced in the rumen or gut of animals, including avians and humans.
It is yet another object of the present invention to provide electrolytes and antacids in a form such that the active ingredients are released gradually over time.
It is still another object of the invention to provide a sodium or magnesium antacid balanced with respect to potassium, sodium and chlorine to maintain the electrolyte balance under heat stress conditions.
It is yet another object of the present invention to provide a pelletized feed supplement in a form which is resistant to abrasion.
Other objects of the invention will be apparent to those skilled in the art from the following detailed description and claims.
The foregoing objects of the present invention are achieved by providing a pellet comprising an antacid selected from the group consisting of sodium and magnesium antacids, said pellet containing potassium, sodium and chlorine in a weight ratio of from about 1.5 to about 1.8 parts of potassium and from about 1.2 to about 1.5 parts of chlorine per part of sodium, said potassium being present in sufficient amount to provide from about 0.8 to about 1 weight parts of potassium per weight part of any magnesium present. Methods of producing the pelletized feed supplement and of administering said feed supplement to both ruminants and humans are also contemplated by this invention.
The pelletized feed supplement of the invention provides several advantages over currently available buffers such as sodium bicarbonate and trona. The pelletized feed provides a nutritionally balanced mixture of the essential elements for maintaining electrolyte balance of potassium, magnesium, chlorine, and sodium. The pelletized feed supplement produces a more gradual change in the pH of the rumen than known bicarbonate buffers. Also, the pelletized feed supplement has a higher buffering capacity than sodium bicarbonate on a weight for weight basis. At higher pH's, the population of microorganisms in the rumen produces more fatty acids which may be used in milk production.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the change in pH over time of strained rumen fluid in an anaerobic chamber. Curve (a) shows the change in unbuffered rumen fluid. Curve (b) shows the pH change in bicarbonate buffered rumen fluid. Curve (c) shows the pH change in rumen fluid treated with the pelletized feed supplement of the present invention.
FIG. 2 shows the difference in rate of dissolution of agglomerated (curve a) versus unagglomerated (curve b) rumen buffer.
DETAILED DESCRIPTION OF THE INVENTION
The antacid and electrolyte sources which are used to make the pellets of the present invention can be any feed grade or better quality material which is not toxic to the animal. The antacids which may be used include magnesium oxide, sodium bicarbonate, dolomite, sodium hydroxide, calcium hydroxide, calcium carbonate, magnesium carbonate, sodium carbonate, northupite and mixtures thereof. Suitable electrolyte sources which may be used in the practice of the invention are any that are conventionally used as animal or human nutritional supplements, including potassium chloride, langbeinite, potassium bicarbonate, arcanite, potassium hydroxide, potassium phosphates, potassium carbonate, sodium chloride, and mixtures thereof. It is important that the weight ratio among elements be within about 10% of 1.65:1:1.35:1.88 of K:Na:Cl:Mg, that is to say the pellet should contain from about 1.5 to about 1.8 parts of potassium and from about 1.2 to about 1.5 parts of chlorine per part of sodium. The magnesium is not required, but if it is supplied in the antacid, it should be balanced by the other elements in the appropriate ratio. That is to say that magnesium: potassium should be within about 10% of 1.14:1, or from about 0.8 to about 1 weight parts of potassium per weight part of any magnesium present. The amounts and types of electrolytes to be added to the antacid to provide the specified ratios can be readily chosen by one skilled in the art.
In the preferred embodiment of the invention, the components of the pellets are agglomerated to form pellets having a size of at least about plus 48 mesh and desirably from about 48 to about 8 Tyler mesh. It has been determined that the rate at which the pellets dissolve in the rumen or stomach is greatly decreased if the components, of the pellet, e.g., the antacid and electrolytes, are ground prior to agglomeration. Generally, the particle size of the components should be reduced to less than 100 Tyler mesh, and preferably to less than 250 mesh.
Surprisingly, it has been found in accordance with this invention that agglomeration not only slows the rate of dissolution of the pelletized feed supplement, but also causes a greater total pH change in the rumen or stomach than unagglomerated material. Reasons for the alteration in the antacid characteristics of the pelletized feed supplement are not precisely known. However, it has been found that the preferred method of preparing the pellets of the present invention, i.e. grinding of the ingredients to achieve a substantially uniform particle size of less than 100 Tyler mesh and agglomerating, results in a chemical reaction.
Generally, there is a range of about 5% by weight of the dry ingredients of liquid which may be employed for any particular composition which will achieve pellets of appropriate sizes and durability. This range will vary with the particular materials employed in the composition and the size of the materials. The range for a particular composition can be determined by routine testing. Too much liquid will lead to pellets which are too large and which are wet and sticky. Too little water will lead to particles which are too small, and are additionally weak and crumbly. Generally, as the fineness of the particles increases, more liquid is required to agglomerate properly. Liquids other than water may be used, for example, a solution of choline chloride may be used advantageously. Amounts of water or other liquid which are added to form pellets are generally between about 10 and 25% by weight of the other ingredients. This proportion of liquid to solids produces pellets of appropriate dimensions.
It also has been found that when binders, such as starch, hydraulic cement, and clay binders, are added to the pelletized feed supplement, the resistance of the pellets to breakage and abrasion is increased. In one preferred embodiment bentonite (a clay binder) is added to the formulation for the pelletized feed supplement. Suitable amounts of bentonite are generally less than about 5% by weight, and preferably about 2%. Further, it has been found that addition of certain widely used components such as molasses may have an adverse effect on the dissolution characteristics of the pelletized feed supplement, causing the solubilization rate to increase. Conversely components such as cement and bentonite decrease the rate of solubilization.
The initial ingredients may be ground individually or together to achieve good mixing. This may be accomplished by any of the means known in the art, such as using ball mills, jet mills, pulverizers and hammer mills. Any means which will achieve the desired degree of fineness is suitable. The inventors have found that a disc pelletizer is well-suited for carrying out the agglomeration of the ground materials, although other apparati may be used. The agglomeration of the ground ingredients may be performed by drum, disc, cone or pan pelletizers, pressure compaction, extrusion, or any other means known in the art.
After the pellets have been formed by agglomeration, they may be dried at either ambient or higher temperatures to remove moisture. A vibrating fluidized bed dryer has been found to be suitable for this purpose. The dried particles can be screened to ensure that they are of the proper dimensions. Oversized granules may be discarded or reduced in size, for example, by means of a knife granulator.
After the processing involved in producing the pellets of the present invention, new compounds may be found, indicating that a chemical reaction has occurred. For example, when potassium chloride, langbeinite, magnesium oxide and sodium bicarbonate are present in the initial mixture, northupite has been detected by means of x-ray diffraction in the pelletized product as a major reaction product. Thus, the method of the present invention provides a means of making northupite. Arcanite has also been tentatively identified in the product.
The pelletized feed supplement may conveniently be admixed with an animal feed. Suitable amounts of the pelletized feed supplement to be admixed with the feed are between 0.5 and 5% by weight of the feed. Preferred amounts are between 2 and 4%.
It is also contemplated that the pelletized product of the present invention may be used by humans. The pelletized feed supplement could be admixed with food, or preferably could be swallowed as a tablet. Such administration would have the beneficial effects of reducing the acidity of the stomach (alleviating heartburn) and helping to maintain the electrolyte balance, which is often perturned under heat stress conditions, such as after strenuous exercise. Suitable amounts of the pelletized feed supplement to be administered to humans are between about 0.3 and about 0.8 grams per kilogram of body weight.
The following examples are not intended to limit the invention but merely exemplify particular embodiments thereof.
EXAMPLE 1
An in situ method was used to evaluate the relative rate of dissolution of selected agglomerated pelletized feed supplement formulations compared to sodium bicarbonate.
A 5 g sample of the test material was placed in a labelled, dry, nylon bag. The bags were secured to an iron weight and placed into the ventral section of the rumen of a fistulated steer. After a given period of time the bags were removed, rinsed with deionized water to remove attached external particles, and then dried overnight at 100° C. After equilibrating to room temperature the bags were reweighed. The percent disappearance was determined from the test material weight loss. The data are shown below.
TABLE 1______________________________________ Duration of Rumen Ex- Material Material posure (hrs) Loss (g) Loss (%)______________________________________Pelletized feed supplement 8 1.38 27.6NaHCO.sub.3 8 4.35 87.0Pelletized feed supplement 16 1.52 30.4NaHCO.sub.3 16 4.97 99.4Pelletized feed supplement 24 2.43 48.6NaHCO.sub.3 24 4.91 98.2______________________________________
The composition of the pelletized feed supplement tested in these examples consisted of 26.15% MgO, 32.65% NaHCO 3 , 22.85% KCl, 16.35% langbeinite, 2.5% sodium-bentonite, 12.5 weight % deionized water. All the dry ingredients were ground to a particle size of less than 250 mesh prior to agglomeration.
These data indicate that the pelletized feed supplement dissolved more slowly in the rumen than sodium bicarbonate.
EXAMPLE 2
The in situ method described above was used to compare agglomerated with unagglomerated formulations. The data shown below in Table 3 demonstrate that agglomeration reduces the amount of dissolution in 24 hours. The compositions used are described in Table 2.
TABLE 2______________________________________Description of Rumen Buffer Stress Mix FormulationsIngredients (%)RumenBuffer Choline De-Stress Lang- Chloride ionizedMix No. MgO NaHCO.sub.3 KCl beinite 70% Soln. Water______________________________________1 26.48 32.41 23.52 17.59 12.0 102 26.23 32.09 23.28 17.41 12.0 11______________________________________ All ingredients were ground for 30 minutes before agglomeration. The liquid components are omitted from the % calculation of dry ingredients.
TABLE 3______________________________________In Situ Evaluation ofBuffer/Stress Mix Formulations:Agglomerated vs. Unagglomerated Duration of RumenMaterial Exposure Material MaterialDescription and No. (h) Loss (g) Loss (%)______________________________________#1, agglomerated 24 2.781 55.62#1, unagglomerated 24 2.942 58.84#2, agglomerated 24 2.856 57.12#2, unagglomerated 24 2.936 58.72______________________________________
EXAMPLE 3
An in vitro method of evaluating the pelletized feed supplement was used with strained rumen fluid in an anaerobic chamber. For each sample to be tested, three 200 ml Erlenmeyer flasks were used: one for the pelletized feed supplement (composition as described in Example 1), one for the sodium bicarbonate control, and one for the unbuffered rumen fluid. Comparisons were made on a gram-equivalent sodium bicarbonate basis. Equal quantities of rumen fluid were added to the flasks containing their respective treatments. All flasks were stirred on magnetic stir plates at a constant rate. Measurement of the pH of the contents of the flasks were made at various times. As can been seen in FIG. 1, the pelletized feed supplement caused a more gradual change in the rumen pH than did the sodium bicarbonate. In addition the absolute magnitude of the change was much greater, the pelletized feed supplement achieving a pH of approximately 8.4 within 2 hours, while the bicarbonate buffered sample only reached a pH of 7.3.
EXAMPLE 4
The in vitro method described in Example 3 was used to compare agglomerated versus unagglomerated buffer stress mix. The composition of the buffer stress mix was: 23.72% MgO, 29.64% NaHCO 3 , 20.75% KCl 14.82% langbeinite, 11.07% dry choline chloride (60%), 20% deionized water. The dry ingredients were ground to a particle size of less than 250 mesh prior to agglomeration.
As shown in FIG. 2, the agglomerated formulation dissolved more slowly than the unagglomerated, and caused a greater pH change.
EXAMPLE 5
Four groups of three cows each were fed on four different regimes in a Latin square design. One treatment was 1% sodium bicarbonate supplemented feed. Another treatment was 1% of the pelletized feed supplement described in Example 1 in the feed. A third treatment was 3% of the pelletized feed supplement described in Example 1 in the feed. The control treatment was unsupplemented feed. The feed which all groups received was a highly fermentable and acid generating ration. The ration contained 30% coarsely-ground wheat, 15% soybean meal, 10% ground corn, 40% corn silage, and 5% coastal bermuda grass hay. The cows were fed two times daily and milked two times daily. The test period ran for 28 days. Milk samples were taken on days 20, 21, 27 and 28 of each period to analyze for composition.
As can be seen in the results shown below in Table 4, dry matter intake was not effected significantly by any of the treatments relative to the control. In addition, milk yield was not substantially effected by any of the treatments. However, the yield of milk fat was substantially effected by the buffer treatments, with the 3% pelletized feed supplement causing the greatest yield improvement. The 1% NaHCO 3 and 1% pelletized feed supplement regime improved the 4% fat corrected milk by about 5%, while the 3% pelletized feed supplement regime enhanced this parameter by about 11%. These data indicate that the pelletized feed supplement of the present invention is as effective or more effective than NaHCO 3 as an alkalizing agent or buffer for dairy rations. The 3% pelletized feed supplement contains equivalent quantities of NaHCO 3 as 1% NaHCO 3 , and yet it enhanced performance to a greater extent.
TABLE 4__________________________________________________________________________ 1% Pelletized 3% Pelletized Control 1% NaHCO.sub.3 Supplement Supplement__________________________________________________________________________Dry Matter 17.4 17.7 17.4 17.4Intake, -(kg/cow/day)Milk Yield, 18.9 19.1 18.4 18.7(kg/cow/day)Milk Fat, (%) 2.97 3.21 3.43 3.67Milk Fat Yield, 0.59 0.60 0.61 0.67(kg/cow/day)4% fat corrected 15.8 16.7 16.5 17.5milk(kg/cow/day)__________________________________________________________________________ | A pelletized feed supplement is supplied which effectively increases productivity of animals fed high acid producing diets. The pelletized feed supplement can also be used to neutralize stomach acid of humans and to maintain a proper electrolyte balance. A method is taught of producing the pelletized feed supplement which results in a buffering agent which is dissolved gradually, and has a high buffering capacity. | 0 |
BACKGROUND OF THE INVENTION
Heat shrinkable tubing has been used for a number of years to replace tape and other tediuous means for protecting splices in cable and repair of pipe, etc. Commonly, the splice to be insulated or the pipe or cable to be covered is cut to permit the tube to be slipped over one segment followed by rejoining the cable or pipe, then slipping the heat shrinkable tube over the repair or splice. In many cases, however, it is not practical to slide a preformed tube over the splice or repair, it is useful to have a heat shrinkable member formed into a tube having an open longitudinal seam. Such a tube can be slipped around an existing splice or section of pipe or cable to be repaired eliminating the need to cut the cable in order to place the protective covering over it.
Heart shrinkable articles having such a tubular form have been disclosed in the literature as shown in U.S. Pat. No. 3,379,218. The method of closing the tube seam heretofore has consisted of some mechanical closure such as a metal rail, buttons, clamps, etc., to keep the fwo faces of the tube together during the heat shrinking process. A rigid mechanical closure has heretofore been found to be necessary because of the very high shear forces acting on the two ends which are held together during shrinking. While these mechanical closures have been successful in preventing the two edges from coming apart during heat recovery, they result in a bulky closure whose cross sectional area is much greater than wall thickness of the heat recoverable member. Therefore, during the heat shrinking or recovery process the wall of the tube becomes much hotter than the mechanical closure resulting in greater stress on the wall of the item during recovery which can lead to a split in the recovering portion. In order to simplify the closure system and avoid the disadvantages of mechanical closing means noted above, the employment of adhesives to bond the two ends of the closure sheet together has been described as in U.S. Pat. No. 3,770,556 and U.S. Pat. No. 3,959,052. So far as is known, closures of the type described in the first of the above two patents have not seen commercial use, presumably because adhesive bonds of the type described have not been sufficiently strong. The closure method described in the second of the above two noted patents has been in commercial use and provides a completely satisfactory closure. This method requires the use of lower alkyl-alpha-cyanoacrylate adhesives. These adhesives form bonds of enormous strength and result in finished closures which are entirely satisfactory. These adhesives, however, are chemically reactive and very quick setting. The adhesives must, however, be employed in the field, frequently under awkward working conditions and some users of such closures have been reluctant to make use of the cyanoacrylate adhesives because they must be handled with care if injury to personnel is to be avoided.
It is the object of the present invention to provide an adhesive means of sealing two edges of a heat shrinkable or recoverable article to form a tubular member around the item on which the member is being shrunk for purposes of repairing leaks, sealing splices or cable junctions which does not require field use of an adhesive which presents any hazard to personnel.
BRIEF DESCRIPTION OF THE INVENTION
The wrap around closures of the present invention comprise generally rectangular sheets of heat shrinkable polymer having a large central section which has been hot stretched and cooled to ambient temperature while in stretched condition and two small, flat unstretched end sections integrally attached to the central section. Each end section is covered with a layer of non-silicone adhesive, the adhesive layer is overlayed with a layer of silicone adhesive the upper surface of which is protected by a peelably removable cover layer. Optionally the non-silicone adhesive layer may be covered with a thin non-adhesive sheet of material such as metal foil, paper or plastic and in this embodiment this silicone adhesive layer is laid down on the upper surface of the non-adhesive sheet.
THE DRAWINGS
FIG. 1 of the appended drawings is a plan view of the closure sheet.
FIG. 2 of the drawings is a cross section of the closure sheet.
FIG. 3 of the appended drawings is an enlarged sectional view of one of the end sections of the closure sheet.
DETAILED DESCRIPTION OF THE INVENTION
The plastic sheet shown in FIG. 1 can be prepared by molding or extruding a flat sheet of a polyvinyl plastic material which is then cross-linked either by chemical means or by radiation. The molded or extruded sheet is then heated above the melting point of the crystalline portion of the cross-linked plastic material and while at elevated temperature, the two opposite end edges of the sheet are clamped and the material between the clamped edges is stretched and cooled below the crystalline melting point of the material while it is still in expanded condition. The resulting sheet has a central section which is heat shrinkable or heat recoverable and two end edges which, not having been stretched, do not shrink when heated. When it is desired to put the sheet into the tubular form, the sheet is shaped into tubular form after hot stretching and before the central section has been cooled to ambient temperature. In order to insure that the two flat end sections do not become involved in the stretching process, it may be desirable to cool the clamps which hold these end sections during the hot stretching process.
A sheet generally similar to that shown in FIG. 1 can also be prepared by extruding a plastic tube, hot stretching the tube until its circumference is about one and a half to four times the circumference of the original tube, slitting the tube from end to end so that it could be opened to form a rectangular sheet and then heating a narrow section of the plastic on each side of the slit to shrink these narrow section to pre-stretch dimensions. The result is a sheet in which the narrow sections which have been shrunk to pre-stretch dimension constitute the tabs or end sections 2 which are not heat shrinkable.
The plastic material from which the sheet shown in FIG. 1 can be formed can be any plastic material having the property of being stretchable to about 2 to 4 times its original dimension when heated above the melting points of its crystalline portion and then, if it is cooled while in stretched condition, having the property of returning toward its original dimension when heated to about 250°-375° F.
The preferred plastic materials are cross-linked vinyl polymers such as high density polyethylene, low density polyethylene, ethylene-vinyl acetate copolymers, ethylene-alkyl acrylate copolymers, chlorinated polyethylene, chlorosulfonated polyethylene, ethylene-propylene copolymers or mixtures of polyethylene with any of the modified polyethylenes. The cross-linking can be accomplished either by chemical treatment with peroxides such as dicumyl peroxide, 2,5 bis(t-butyl peroxy)-2,5 dimethyl hexane, αα'-bis(t-butyl peroxy) di-isopropyl benzene and the like or by subjecting the polymers to intense radiation.
FIG. 2 of the appended drawings is a cross-section of the complete closure device of the invention. Elements 1 and 2 in the drawing correspond to elements 1 and 2 of FIG. 1 being, respectively, a large central section which has been hot stretched and cooled while in stretched position and relatively small, unstretched sections which are integral with stretched section 1. Layers 3, 4, 5 and 6 which overlay the unstretched sections 2 are, respectively, a layer of a non-silicone adhesive, a non-porous non-adhesive layer, a silicone adhesive layer and an adherent cover layer. These several layers overlay the upper surface of the righthand unstretched section 2 and the lower surface of the left-hand unstretched section 2. The use of the non-porous non-adhesive layer is optional, it may be omitted and the silicone adhesive layer may be laid down on the surface of the non-silicone adhesive layer.
FIG. 3 of the drawings is an enlarged view of the multi-layer arrangement shown in respect to the righthand unstretched section 2 of FIG. 2. Non-silicone adhesive layer 3 is a thin layer of strongly adhesive material such as a lower alkyl cyanoacrylate adhesive such as the adhesive available commercially under the tradename LOCTITE 414, an epoxy adhesive or a neoprene adhesive. Layer 4 is optional but when used is a non-porous substrate material which may be glasscloth or a relatively inert strong plastic film such as a polyimide film. Suitable polyimide films are sold under the tradenames NOMEX and KAPTON. Layer 5 is a silicone adhesive such as diphenyl dimethyl siloxane. After application of the silicone adhesive to the substrate, it is preferably subjected to thermal treatment at about 300° F. for a short time to increase bond strength apparently by cross-linking. Cover layer 6 is a non-porous adherent which may be paper or a plastic film, the surface of which contracting the silicone adhesive is coated with an abherent material such as a wax or a metal salt of a higher fatty acid such as zinc, aluminum or calcium stearate. The abherent sheet is not strongly bonded to the silicone adhesive and may be readily peeled from its surface. Sheets of material consisting of layers 4, 5 and 6 assembled in the order shown in the drawing are commercially available. Also commercially available are strips of material consisting of materials of layers 4 and 5 shown in the drawings, for example, PERMACEL which is a glasscloth covered with a layer of silicone adhesive or SAUNDERS S-51 which is a polyimide (KAPTON) film coated with a silicone adhesive. These materials may be used in the preparation of the wrap around enclosure but when they are used, the abherent cover sheet 6 must be applied to their upper surfaces. These commercial products are commonly pretreated either thermally or chemically to strengthen the bond between the silicone resin and the substrate.
The surface of the closure sheet which is to be in contact with the material to be enclosed may be covered with a layer of hot melt sealant (not shown in the drawing) for the purpose of bringing the heat shrunk plastic sheet into close and continuous engagement with the article to be covered. Suitable sealants are well known in the art and include materials such as vinyl acetate polymer, wax, polyisobutenes, polyamides and the like.
EXAMPLE
A mixture of 50 parts low density polyethylene and 50 parts of chlorosulfonated polyethylene was compounded with carbon black, stabilizers and catalyst (1.5%), 2,5 bis(t-butyl peroxide) 2,5 dimethyl hexane. A slab molded from this material was cured at about 330° F. for five minutes and removed from the mold. The slab measured 4 by 5 inches and was 0.06 inch thick. The two opposite ends of the slab were clamped 0.75 inch in from the edge and the central section was heated to approximately 300° F. and stretched to a length of 10 inches and then cooled while in expanded condition. The righthand end section was then coated with a thin layer of lower alkyl cyanoacrylate adhesive (LOCTITE 414). A strip of material having dimensions corresponding to the surface of the end section and consisting of a polyimide film substrate, a layer of silicone adhesive (diphenyl dimethyl siloxane polymer) and a strip of paper having an abherent coating on its lower surface. This three-layer strip of material was pressed down on the cyanoacrylate adhesive so that the polyimide film was in contact with the cyanoacrylate. The lefthand unstretched section was covered in the same manner but the covering was applied to the face of the lefthand unstretched section opposite to that of the righthand unstretched section previously covered. The hot stretched central section was coated with a layer of ethyl vinyl acetate polymer to function as a hot melt sealant. The sealant was applied to only one surfce of the stretched central section. The sheet was then wrapped around a two inch cable with the hot sealant surface in contact with the cable. The abherent cover layers were peeled from the silicone adhesive on each end strip and the two layers of silicone adhesive were pressed together and adhesively joined. A gas fired propane torch was then applied uniformly to the entire surface of the wrap around closure which was now in tubular form bringing the temperature of the wrap around sheet to a level above about 300° F. and the heating was continued until the closure shrunk into firm contact with the cable.
The silicone-to-silicone adhesive bond regularly exhibits a shear strength above 10 lbs. per inch and forms a secure closure.
The closure of the present invention has several significant advantages over the closure described in U. S. Pat. No. 3,959,052. The cyanoacrylate adhesives do not bond strongly when applied at temperatures below about 30° F. while the silicone adhesives bond strongly at sub-zero temperatures. Cyanoacrylate adhesive has to be applied to the surfaces of the polymer sheet in the field and since this adhesive is a very quick setting adhesive, any lack of care by the workman applying it would result in skin-to-skin bonds so that workmen could find two or more fingers stuck together which is, as a minimum, a nuisance and can be hazardous. The silicone-to-silicone adhesive bond is not affected by the presence of water which is frequently a material present in field application, in fact, the silicone-to-silicone bond can be made under water.
Recourse to the multilayer arrangement above-described was made necessary because it was found that when the two unstretched end sections were simply coated with silicone adhesive, then the two silicone layers were brought together, the silicone-to-silicone bond was completely strong but the silicone adhesive did not adhere strongly to the cross-linked polyolefin sheet. Because of the weakness of this silicone to polymer sheet bond, it was found necessary to use the layer of non-silicone adhesive on the upper surface of which a layer of silicone adhesive is disposed. Optionally a non-adhesive, non-porous support sheet may be bonded to the non-silicone adhesive and the silicone adhesive layer is then disposed on the upper surface of the support sheet. | Wrap around closures for cables, pipes, splices, and junctions to effect repair, insulation, waterproofing and the like and a method for preparing such closures are described. The closures comprise generally rectangular sheets of heat shrinkable polymer having a large central section which has been hot stretched and cooled while in stretched condition and two small, flat unstretched end sections integral with the central section. Each end section has a layer of non-silicone adhesive covering one of its surfaces, optionally a layer of non-porous support material covering and adhering to the adhesive layer, a layer of silicone adhesive covering and adhering to the non-silicone support layer and a peelably removable cover layer covering the upper surface of the silicone adhesive layer. The several layers lie on the upper surface of one of the end sections and on the lower surface of the other end section. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of Italian Patent Application PD2011A000164, filed on May 23, 2011, and PCT Application PCT/IB2012/052566, filed on May 22, 2012, both incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The object of the invention is a product composed of a flexible polyurethane foam and a polymeric gel and the relative production process for making it, which is to be used as a padding material, in particular for mattresses, pillows and bedding articles, in footwear, in the car industry, providing the required characteristics in a durable stable manner, with a reliable and inexpensive production process that includes the steps of delivering a polyurethane foam to be expanded on a continuous production conveyor using a foaming head or a mold, where said polyurethane mix has granules of polymeric gel added to it.
DISCUSSION OF RELATED ART
[0003] As is well known, open or closed cell polyurethane foam in the various available densities is used in many fields.
[0004] The chemistry of the polyurethane is based on the reaction of isocyanates with molecules containing active hydrogenates. The —NCO groups contained in the isocyanate molecule react quickly, in the presence of suitable catalysts, with hydrogen atoms bound to more electronegative atoms of carbon.
[0005] This reaction leads to the formation of the polymeric structure, with the associated production of carbon dioxide when water is present in the reaction.
[0006] Normally, for the production of finished polyurethane foam products you can use a mold or else, more frequently, a process for producing continuous blocks that are later cut and shaped. From storage tanks, suitably sized and structured for the raw materials and additives that are used, the chemical components are transported using dosing pumps into a mixing room where the raw materials and the additives are weighed and mixed according to a fixed formula. The isocyanate raw material does not take part in this dosing. The isocyanate and the mix obtained in the mix room are sent by means of dosing pumps to the mixing and supply head. The mixing and supply head is part of a foaming line where, in the case of the production of continuous blocks, a conveyor of polyurethane foam is produced, with a prearranged height and cut to the desired length for the production of long blocks of polyurethane. The blocks of polyurethane obtained in this manner are stored in tiers where they mature. In the case of mold production, the production line is composed of a series of molds having the shape of the product you want to make, the production sequence is the same, and you put a set amount of product in the mold using the mixing head, the mold is closed, and the polymerization reaction takes place inside and then later the piece is taken out and put in tiers for maturation.
[0007] The introduction into the production process of additive substances with special mechanical or physical properties is extremely critical. The formulation of the polyurethane, in fact, requires a skilful balance in order to provide a foam product with regular and homogeneous characteristics, and to therefore provide an industrially acceptable product with the desired characteristics. If additives are used these could cause unwanted reactions between the main additive and the raw materials used in the process for producing flexible polyurethane foams, thereby causing instability in the system and a loss of the characteristics of the additive.
[0008] The addition of acrylonitrile butadiene styrene, with characteristics that leave a lot to be desired, to the polyurethane mix in the process of forming is well known.
[0009] Indeed, the performances of the polyurethane do not change, except for the mass, in an insignificant manner, while high concentrations lead to a decline of the product over the long term.
[0010] In fact the increase in rigidity with the addition of styrene acrylonitrile and butadiene loads to obtain polyurethane that is a little more rigid, and in any event to improve the physical characteristics of the product, does not achieve the desired effect in appreciable percentage.
[0011] Also the addition of calcium carbonate and the like does not obtain any other effect.
[0012] On the market there are particular polyoils already doped with acrylonitrile butadiene styrene (normally called SAN), however they do not achieve a significant increase in the characteristics compared to the polyurethane doped afterwards.
[0013] In particular, none of the current polyurethanes doped afterwards, or the SAN variety, offer a high viscoelasticity compared to standard polyurethanes, and in particular they have a modest energy absorption coefficient value.
[0014] In order to get around the above-mentioned drawbacks there was also an attempt in the past to combine the polyurethane gel, both before and during the polymerization phase, to one of the ingredients, with poor results because the gel does not disperse in the mass of the polyurethane.
[0015] Other tests were carried out combining a polyurethane gel after a first and partial polymerization; however the surface accumulation led to the inevitable detachment in the long term because the substances had no affinity to one another.
[0016] In the broad diversity of products obtainable, it is well known that the use of additives should take place in the form of powder in order to allow for foaming.
[0017] All attempts up until now to insert additives in the posterior phase to the foaming have proven to be limited only to the surface layer.
[0018] Moreover, in the eventuality that these additives have no chemical affinity with the chemical structure of the polyurethane, like for example a polymeric gel, the surface diffusion creates an upper layer of film that is only partially integrated into the substrate.
[0019] This layer of film has shown to be unstably joined to the body of the substrate of the polyurethane, and over time this union breaks down with the separation of the entire upper part of the additive, either in the form of a film or in the form of small surface elements.
[0020] This drawback, especially regarding the reliability of the cohesion, has led to experiments with other additives, to be added in the form of powder, which have some affinity with the polyurethane.
[0021] It is well known that the polymeric gel, in order to be able to provide a feeling of freshness, has to find itself united in discrete elements sufficiently large and substantial to be able to absorb, at least in the initial phase, the heat of the person resting on top of it.
[0022] We have seen, however, that these discrete elements deposited afterwards to the foaming are settled only on the surface and cannot get inside the structure, and over time they break off.
[0023] Finally, the production procedure for combining said polymeric gel to one of the polyurethane components, the polyoil, or to the mixt of polyoil and isocyanate, has serious drawbacks if carried out near the foaming.
[0024] Indeed, the gel element does not sufficiently stick to the structure of the polyurethane, with the result that the polymeric gel on the surface separates over time following rubbing and wear.
SUMMARY OF THE INVENTION
[0025] In this situation the main objective of this invention is to make available a composite material for making polyurethane items doped with polymeric gel that has better mechanical and physical properties than the doped polyurethane available on the market.
[0026] In particular, the objective of this invention is to make available a composite material for making items out of polyurethane doped with polymeric gel that has improved viscoelastic properties, with a lowering of the glass transition point with respect to the doped polyurethane available on the market.
[0027] A further objective of this invention is make a polyurethane foam doped with a polymeric gel without the drawbacks of the prior art.
[0028] A further objective of this invention is make flexible polyurethane foam doped with a polymeric gel that firmly maintains said polymeric gel anchored in a stable manner over time, and which does not change its characteristics in the long term.
[0029] A further objective of this invention is to make available a composite material for making items out of polyurethane doped with a polymeric gel that does not have any release or detachment of said polymeric gel.
[0030] A further objective of this invention is to make available a composite material for making items out of polyurethane doped with a polymeric gel that has a uniform distribution in the body of the polymeric gel.
[0031] A further objective of this invention is to make available a composite material for making items out of polyurethane doped with a polymeric gel that has improved thermal exchange properties.
[0032] A further objective of this invention is to make available a composite material for making items out of polyurethane doped with a polymeric gel that has appreciable characteristics of freshness that flexible polyurethane foam does not have because it is one of the best insulators.
[0033] A further objective of this invention is to make a polyurethane foam that has a high viscoelasticity value and therefore a higher energy absorption coefficient value compared to traditional polyurethane foams.
[0034] A further objective therefore of this invention is to provide a process for obtaining a polyurethane foam product that can provide the properties of the polymeric gel in an enduring and efficacious manner.
[0035] A further objective of this invention is to make available a procedure for making items out of polyurethane doped with a polymeric gel that is completely reliable.
[0036] A further objective of this invention is make a composite material for making items out of polyurethane doped with a polymeric gel, without using methods or additives that could harm people's health.
[0037] A further objective is to make available a procedure that ensures the secure holding of the polymeric gel also on the surface.
[0038] Another objective is to make available a procedure that allows you to prepare beforehand the components of the polyurethane mix.
[0039] These and other objectives are all attained with the composite material for making items out of polyurethane doped with polymeric gel, and with the procedure for making items out of polyurethane doped with polymeric gel according to the attached claims.
[0040] Other inventive aspects of the invention are described in the claims.
[0041] Additional characteristics and advantages of the process and the product will become clearer from the detailed description that follows of some preferred forms, provided by way of example.
DESCRIPTION OF THE DRAWINGS
[0042] The technical characteristics of the invention, in line with the above-mentioned objectives, can clearly be found in the contents of the claims above and the benefits of it are even more evident in the detailed description that follows, made with reference to the attached diagrams, which depict a form that is provided purely by way of example and non-binding, where:
[0043] FIG. 1 shows a diagram of a ramp compression DMA analysis with a temperature between −60° to +100° C. at 5° C./min (frequency 1 Hz) referring to a non-doped
[0044] FIG. 2 shows a diagram of a ramp compression DMA analysis with a temperature between −60° to +100° C. at 5° C./min (frequency 1 Hz) referring to a sample doped with polymeric gel (with a percentage of about 10%);
[0045] FIG. 3 shows an enlarged photo of the cellular structure of a standard polyurethane with a graduated scale in mm.; and
[0046] FIG. 4 shows an enlarged photo of the cellular structure of the polyurethane foam that is the object of the invention, with the chips or granules of the polymeric gel highlighted with arrows.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0047] The composite material and the procedure set out in the invention are preferably to be used for making mattresses, pillows, and bedding articles in general. The product is made from two products of a different nature.
[0048] The flexible polyurethane foam is composed of two components A and B; component B is an isocyanate, component A is a mix of different polyoils doped with catalysts, water and various additives.
[0049] The second product is a polymeric gel.
[0050] Preferably, but not essentially, the polymeric gel is chosen from the family of thermoplastics, is a SEBS rubber (Styrene-Ethylene-Butylene-Styrene), and the plastic phase is generally of a polyolofinic nature.
[0051] The advantages of using the above-mentioned gel for making items to be used in bedding are that it is chemically very stable, releasing little plasticizer, it is sanitary, namely inert and nontoxic, and it is washable.
[0052] Preparation takes place in the following way: the polymeric gel is reduced to chips or granules with dimensions that can range from a fraction of a millimeter to 5 millimeters. The polyurethane can be of various types, flexible elastic foam, viscoelastic with high or low resilience, slow return or immediate return (when squashed the recovery time to the initial position depends on the type of polyurethane), this goes for all types of flexible polyurethane foam.
[0053] The chips of polymeric gel are immersed and mixed using an agitator that disperses them evenly in a mix of component A.
[0054] The percentages of gel of the total of the end product can go from a minimum of 2% to a maximum of 50%.
[0055] The best results were obtained with a gel percentage from 5% to 20% of the total of the end product.
[0056] Getting back to the preparation, once the gel is mixed with the mix of polyoils and various additives (this mix later in the description will be identified as mix with gel) you proceed to the making of the product that takes place by making the mix with gel component react with the isocyanate.
[0057] Very conveniently, the immersion of the polymeric gel into the polyoil is done in a time from the preparation of the isocyanate and polyoil mix of about half an hour to about 4 hours, and preferably 2 hours, and this allows the polyoil to penetrate inside the gel, something that is important for our purpose; in fact, because the polyoil is a macromolecule it remains partially outside the gel, allowing the gel itself to bind in the reaction phase with the isocyanate part to form the polyurethane; the end result is a gel, that although a solid inert substance, is retained, and when it is used the resultant polyurethane does not have gel granules that detach from it.
[0058] Another production method also beneficially provides for the combining of the polymeric gel with one of the components of the polyurethane mix a long time before the foaming, from a few hours up to 48 hours. This preparation provides for the immersion of the gel into the isocyanate: the gel is immersed into the isocyanate to avoid the problem of the gel being absorbed by the mix (which is a blend of polyoils, water, catalysts and various additives) that by penetrating over time inside the molecule of the polymeric gel would render the gel saturated with the polyoil after the reaction, making it unusable. The bottom of the storage tank because of the effects of gravity. The doping of the polymeric gel should take place gradually.
[0059] The result is a microcellular elastic foam compound with physical and mechanical characteristics that are comparable to those of the starting polyurethane, which in addition has a high increase in viscoelasticity.
[0060] This increase in viscoelasticity gives the product a higher energy absorption coefficient.
[0061] The product that is obtained acquires also the qualification as an anti-bedsore material since the polymeric gel parts, and especially those parts near the surface, incorporated and held by the polyurethane of the matrix, have a very modest hardness, squashed under the weight of the user to such a degree that they cannot be felt or noticed as bumps, have considerable resistance to abrasion, resistance to UV rays, and because they have a high thermal capacity also provide a feeling of freshness.
[0062] In order to more effectively highlight this characteristic, tests were carried out at specialized labs, and FIGS. 1 and 2 respectively refer to a sample of non-doped polyurethane and a sample of polyurethane doped with polymeric gel (with a percentage of about 10%).
[0063] From the diagrams we can appreciate in particular the increase in viscoelasticity that gives the product a higher energy absorption coefficient, almost 3 times that of traditional polyurethane foam.
[0064] To assess how the chips or granules of the polymeric gel are arranged in the cellular body of the polyurethane, photos were made; the first in FIG. 3 shows the standard structure of the cellular mass of a generic polyurethane, while in FIG. 4 we can see the uniform distribution throughout the cellular mass of said polymeric gel chips and granules, pointed out by arrows.
[0065] The flexible polyurethane foam production process can be carried out using molding in specially made molds for single products that already have a form, or using continuous foaming, with the production of long blocks to be cut and shaped.
[0066] In this way you obtain a family of flexible polyurethane materials in a variety of hardness, but whose performance satisfies customers' tastes and requirements, who very often assess a product on the basis of first impressions, its touch and crush resistance. With the product made according to the procedure set out above, manufacturers are in a position to be able to guarantee durable properties without any undesirable detachment of the doped gel.
[0067] In fact, only with this method is there a guarantee in the long term that the performance of the doped end product will remain unchanged. | A standard polyurethane doped with a polymeric gel uniformly diffused in the body, where the polyurethane acquires the properties of the gel without any change to its structure in a durable stable manner. | 2 |
RELATED APPLICATIONS
This application is related to U.S. patent application Ser. No. 09/161,798 entitled “Apparatus And Method For Correcting Carriage Velocity Induced Ink Drop Positional Errors,” filed concurrently herewith this application on Sep. 28, 1998.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to ink-jet hard copy apparatus and, more particularly, to the art of generating control signals for firing ink droplets from a scanning ink-jet printhead and, specifically to methods and apparatus for compensating for variations in printhead-to-media spacing and printhead scanning velocity.
2. Description of Related Art
The art of ink-jet technology is relatively well developed. Commercial products such as computer printers, graphics plotters, copiers, and facsimile machines employ ink-jet technology for producing hard copy. The basics of this technology are disclosed, for example, in various articles in the Hewlett-Packard Journal, Vol. 36, No. 5 (May 1985), Vol. 39, No. 4 (August 1988), Vol. 39, No. 5 (October 1988), Vol. 43, No. 4 (August 1992), Vol. 43, No. 6 (December 1992) and Vol. 45, No. 1 (February 1994) editions. Ink-jet devices are also described by W. J. Lloyd and H. T. Taub in Output Hardcopy [sic] Devices, chapter 13 (Ed. R. C. Durbeck and S. Sherr, Academic Press, San Diego, 1988).
FIG. 1 depicts an ink-jet hard copy apparatus, in this exemplary embodiment a computer peripheral printer, 101 . A housing 103 encloses the electrical and mechanical operating mechanisms of the printer 101 . Operation is administrated by an electronic controller (usually a microprocessor-controlled printed circuit board, not shown) connected by appropriate cabling to a computer (not shown). Cut-sheet print media 105 , loaded by the end-user onto an input tray 107 , is fed by a suitable paper-path transport mechanism (not shown) to an internal printing station where graphical images or alphanumeric text is created. A carriage 109 , mounted on a slider 111 , scans the print medium. An encoder strip 113 and appurtenant devices (not shown) are provided for keeping track of the position of the carriage 109 at any given time. The fundamentals of encoder tracking are set out in U.S. Pat. Nos. 4,786,803 and 4,789,874 (Majette, et al.) (assigned to the common assignee hereof and incorporated herein by reference in their entireties). A set 115 of ink-jet pens, or print cartridges, 117 A- 117 D are releasable mounted in the carriage 109 for easy access. In pen-type hard copy apparatus, separate, replaceable or refillable, ink reservoirs (not shown) are located within the housing 103 and appropriately coupled to the pen set 115 via ink conduits (not shown). Once a printed page is completed, the print medium is ejected onto an output tray 119 .
An ink-jet pen includes a printhead which consists of a number of columns of ink nozzles. The columns of nozzles fire ink droplets that are used to create a print column of dots on an adjacently positioned print media as the pen is scanned across the media. A given nozzle of the printhead is used to address a given vertical column position, referred to as a picture element, or “pixel,” on the print media. Horizontal positions on the print media are addressed by repeatedly firing a given nozzle as the pen is scanned. Thus, a single sweep scan of the pen can print a swath of dots. The print media is stepped to permit a series of scans. Dot matrix manipulation is used to form alphanumeric characters, graphical images, and even photographic reproductions from the ink drops. Generally, the pen scanning axis is referred to as the x-axis, the print media transport axis is referred to as the y-axis, and the ink drop firing direction is referred to as the z-axis.
Note that when a nozzle is fired, the ink is ejected from the pen at a finite velocity and it must travel a finite distance along the z-axis between the pen and the print media (for convenience and without limitation to the scope of the invention, the word “paper” will be used hereinafter to mean any form of print media). Since the pen is not stopped at each position during scanning in the x-axis, a fired ink droplet will also have a velocity in the x-axis direction as it traverses the distance to the paper surface. Thus, in order to hit a target pixel, any given nozzle should be fired a finite time before the pen positions the nozzle directly over the location where the dot is intended to be printed. However, in the art it is often generally assumed that all drops will have the same offset and thus, without such time of drop firing compensation, overall print quality is not affected even though the image is shifted as a whole. If at all compensated, an average advanced time of the firing signal is calculated by using the expected flight time of the drop and the current pen velocity, each of which is known from the design of a specific implementation of ink-jet hard copy apparatus (e.g., it is known that the maximum allowable carriage speed without print quality degradation is calculated by taking the time it takes for pen control logic circuitry to shift one set of data up to the pen and fire divided by the pen nozzle stagger distance (explained hereinbelow); the flight time is calculated by dividing the nozzle-to-paper spacing by the velocity of the ink drop.
A typical prior art drop firing encoder is shown in FIG. 1A with a timing diagram therefor shown in FIG. 1 B. An encoder 113 provides two output timing signals, “EncA” and “EncB,” which are decoded 121 as fundamental coarse position indicators of where the carriage 109 is during a scan. The leading and trailing edge of each encoder signal can thus be used in conjunction with a counter 122 to generate carriage position, tracking carriage movement in units such as {fraction (1/150)}th inch (this value will be used throughout as an exemplary embodiment herein; no limitation on the scope of the invention is intended thereby nor should any be inferred therefrom). A series of fire timing pulses, “FTP”_COUNT, is generated for each position signal, allowing the FIRE pulse actually to trigger firing of a plurality of nozzles in the printhead. Fire timing pulses are generated continuously by a clock during normal printing and used in accordance with the number of nozzles arrays in a particular printhead design as needed. The Fire Position circuitry 123 combines the position information with a value for a nozzle firing register 123 to generate a nozzle firing pulse, “FIRE,” e.g., every period comprising movement of the carriage {fraction (1/150)}th inch. The leading or trailing edge is also used in a Period_Counter 124 to determine the carriage velocity. Dividing 125 the period by a predetermined number (e.g., 100, taken from an extrapolation_division register (not shown)—a value related to the number of nozzle firing desired per period for a particular printhead implementation, the FTP_COUNT pulses) provides an extrapolation for the timing of the FTP_COUNT pulses. That is, an extrapolator latch 126 _counter 127 takes the measurement of the carriage period as measured in clock cycles divided by the value kept in the extrapolation-division register. The FTP_COUNT pulses are also provided 128 as fine position indicator for carriage position.
However, the horizontal distance from the actual advanced firing position of a given nozzle to where the drop actually lands is dependent on the scanning velocity of the pen. Knowing the total flight time of the ink drop and the pen scan velocity, the distance can be calculated by multiplying these two values. If the scan velocity of the pen is constant, the amount by which the firing signal precedes each pixel position is a constant. As discussed above, in this case the whole printed image is just shifted by a constant amount; that is, the image is moved by the number of dot positions that equal the over-shoot distance. Compensation in the foregoing manner moves the whole rendered image to attempt to compensate simply for this error. However, this does methodology does nothing to improve instantaneous drop placement accuracy within each scan swath.
In fact, when a pen is scanned across the paper, its velocity is not constant. Also, there are pen acceleration and deceleration ramps at each end of a scan which may still be within the intended printing zone on the paper. Firing nozzles during such changing pen velocity causes successive ink drops to land at varying distances from the intended uniform spacing. Furthermore, in order to increase throughput and to improve print quality by using print modes such as checkerboarding the printed pixels' dot matrix pattern on the paper, bi-directional printing is often the preferred print mode. Note also that bi-directional scanning prints pixels in opposite time-of-firing directions, further complicating the pixel alignment. In other words, a trade-off must be made between throughput and image quality in accordance with deciding when to fire ink drops using current fire pulse timing solutions.
Another solution is to make the sweep width wider than the printed area so as not to print on the acceleration and deceleration ramps of a scan but only during supposed constant pen velocity periods; this causes both a throughput penalty and requirement for a larger apparatus workspace footprint.
Moreover, a further problem exists when the nozzle-to-paper spacing is not a constant. The variation in this nozzle-to-paper spacing causes the drop positioning to change non-uniformly across the width of the scan. Therefore, drop positioning will change across the page, causing drops not to hit the intended address pixel grid correctly. Thus, there is a need to calculate the firing advance dynamically to remove positioning errors which would result from changes in the nozzle-to-paper spacing during any one scan.
A further time-of-firing complication is added when a vertical column of nozzles on the printhead is broken into groups, called “primitives,” generally for use with different color inks being fired from a single printhead. In order to prevent having to fire all nozzles simultaneously, within a column and within a primitive, the nozzles are staggered horizontally in the pen scan x-axis direction by an amount slightly less than the space between print columns divided by the number of nozzles per primitive. This means that the firing from one nozzle to the next occurs at a defined spacing, known as the “stagger distance,” (or simply “stagger”) which is less than the spacing between dots on the media. The carriage must move this stagger distance between firing different nozzles of the same column (e.g., stagger time is calculated taking the time it takes the carriage to traverse the {fraction (1/150)}th inch and dividing this time by the number of stagger distances in that {fraction (1/150)}th inch). In this manner, the nozzles of each primitive can fire sequentially to create a vertical column of dots on the paper.
In order to solve these problems, there is a need for dynamically varying the ink drop fire timing as a function of pen velocity. Note that this compensation for flight time assumes pen-to-paper spacing is constant and a static flight-time value can be used when performing pen velocity compensation, while at the same time, the variation in this spacing causes the drop positioning to change across the width of the paper since the pen velocity compensation is being performed statically when a dynamic flight-time may be needed. Thus, there is a need for compensation of both factors in order to deposit ink droplets accurately on intended target pixels.
SUMMARY OF THE INVENTION
In its basic aspects, the present invention provides an ink drop fire timing control device for an ink-jet hard copy mechanism for producing dot matrix printing on print media, the hard copy mechanism including an ink-jet pen and a carriage for scanning the pen across print media along a linear axis. The device includes comprising: a mechanism for generating periodic carriage position signals as the carriage is scanning the pen across print media along a linear axis; a mechanism for producing ink drop fire timing signals based upon the periodic carriage position signals; and a flight compensation mechanism for extrapolating a value representative of expected ink drop flight time error from the pen to the print media and advancing the ink drop fire timing signals to compensate for the expected ink drop flight time error such that ink drop flight time is compensated for velocity changes of the carriage as the carriage traverses the linear axis, wherein scanning position interrupt signals are generated by comparing carriage position with a next predetermined interrupt position.
In another basic aspect, the present invention provides an ink drop fire timing control device for an ink-jet hard copy mechanism for producing dot matrix printing on print media, the hard copy mechanism including an ink-jet pen, a carriage for scanning the pen across print media along a linear axis, and mechanism for generating periodic carriage position signals representative of periodic predetermined pen scanning positions along the axis as the carriage is scanning the pen across print media along a linear axis. The timing control device includes: paper shape compensation mechanism for generating a value representative of expected flight time for each of the periodic predetermined pen scanning positions along the axis calculated from a predetermined paper shape profile; and a mechanism for adjusting ink drop fire timing based on the value representative of expected flight time such that ink drops are ejected from the pen before the carriage positions the pen at a position for firing based on the signals representative of periodic predetermined pen scanning positions along the axis.
In another basic aspect, the present invention provides an ink drop fire timing control method for an ink-jet hard copy mechanism for producing dot matrix printing on target pixels of a print media, the hard copy mechanism including an ink-jet pen having a printhead with a plurality of ink drop firing nozzles arrayed as a staggered vertical column, a carriage for scanning the pen across print media along a linear horizontal axis, and mechanism for generating periodic carriage position signals representative of periodic predetermined pen scanning positions along the axis as the carriage is scanning the pen across print media along a linear axis. The method includes the steps of:
providing a signal indicative of coarse position of the carriage during scanning;
from the indicative of coarse position, deriving a periodic ink drop firing time signal;
from the signal indicative of coarse position, extrapolating a signal indicative of fine position of the carriage during scanning, the fine position being a predetermined subdivision of the coarse position by a number equal to the plurality of ink drop firing nozzles;
providing a signal indicative of expected flight time of a drop from the printhead to the print media;
from the signal indicative of fine position and the signal indicative of expected flight time, deriving a flight time error signal; and
from the flight time error signal, advancing the periodic ink drop firing time signal such that ink drops are fired before the carriage is positioned over a target pixel.
The step of providing a signal indicative of expected flight time of a drop from the printhead to the print media includes the steps of:
programming a paper profile value for each the fine position; and
incrementing the expected flight time when the profile value indicates pen-to-paper spacing is increasing at a fine position along the axis and decrementing the expected flight time when the profile value indicates pen-to-paper spacing is decreasing at a fine position along the axis.
In still another basic aspect, the present invention provides an ink-jet paper shape compensation device for generating a value representative of expected flight time for each of the periodic predetermined pen scanning positions along the axis. The paper shape compensation device includes: a re-loadable down counter mechanism for counting at each of the periodic predetermined pen scanning positions along the axis; and connected to the counter mechanism, mechanism for changing the value representative of expected flight time such that the value representative of expected flight time is incremented when pen-to-paper spacing is increasing and decremented when pen-to-paper spacing is decreasing at each of the periodic predetermined pen scanning positions along the axis.
It is an advantage of the present invention that it improves the ink drop positioning accuracy across a print medium scan by compensating for the change in ink drop flight time during velocity fluctuations and during carriage velocity ramps.
It is an advantage of the present invention that it allows ink drop flight time changes to be implemented as a simple, adjustable, incrementer/decrementer circuit.
It is an advantage of the present invention that it provides compensation for the change in ink drop flight time during variations of printhead-to-paper distance across a print medium scan.
It is another advantage of the present invention that it provides printhead-to-paper distance variation and scanning velocity variation compensation for bi-directional ink-jet printing.
It is still a further advantage of the present invention that it automatically compensates during carriage acceleration and deceleration velocity ramps, allowing a wider print zone than constant velocity printing modes.
It is yet a further advantage of the present invention that accurate printing during velocity ramps allows a narrower carriage travel and permits a smaller workplace footprint for a hard copy apparatus.
Other objects, features and advantages of the present invention will become apparent upon consideration of the following explanation and the accompanying drawings, in which like reference designations represent like features throughout the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 (Prior Art) is a perspective view rendering of an ink-jet hard copy apparatus.
FIG. 1A (Prior Art) is a circuit block diagram for an ink drop firing encoder.
FIG. 1B (Prior Art) is a timing diagram for FIG. 1 A.
FIG. 2 is a circuit block diagram for x-axis, ink-jet carriage velocity compensation in accordance with the present invention.
FIG. 3 is a timing waveform diagram for the circuit shown in FIG. 2 .
FIG. 4 is a circuit block diagram for z-axis, printhead-to-paper distance variation compensation in accordance with the present invention, providing input to the circuit of FIG. 2 .
FIG. 5 is a flow chart for the circuit block diagram shown in FIG. 4 .
FIG. 6 is a schematic depiction of paper shape, discrete linear approximation, correction method as used in the z-axis compensation of FIGS. 4 and 5.
FIG. 7 is a timing waveform diagram comparing uncompensated and compensated fire timing pulses for a printhead scanning speed of 105 inches per second (“ips”) in accordance with the present invention as shown in FIG. 2 .
FIG. 8 is a timing waveform diagram comparing uncompensated and compensated fire timing pulses for a printhead scanning speed of 60 ips in accordance with the present invention as shown in FIG. 2 .
The drawings referred to in this specification should be understood as not being drawn to scale except if specifically noted.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Reference is made now in detail to a specific embodiment of the present invention, which illustrates the best mode presently contemplated by the inventors for practicing the invention. Alternative embodiments are also briefly described as applicable. Subtitles provided herein are for the convenience of the reader; no limitation on the scope of the invention is intended thereby nor should any be inferred therefrom.
General Operation
The present invention uses combinatorial and sequential logic as shown in FIG. 2, referred to generically hereinafter as the Velocity Compensator 200 , to vary the timing of fire pulses to compensate for variation in the x-axis velocity in a nozzle firing timing circuit. An accompanying timing waveform diagram is provided in FIG. 3 in which:
EncA is a first encoder output;
EncB is a second encoder output;
Position is a counter output based on EncB/EncA;
Edge is the pulse generated from decoding EncB with EncA in the same state;
ExtPos is the extrapolated pulse train derived from EncA and EncB;
FTP is the fire timing pulse train; and
ColumnSync is the extrapolated firing pulse including a derived flight time error.
Keeping FIG. 1 at hand, the encoder strip 113 is used to generate a series of pulses, EncA and EncB, as the carriage 109 translates back-and-forth along the x-axis. Normally in the prior art, such as taught by Majette et al. in U.S. Pat. No. 4,789,874, the encoder signal will be used to generate nozzle firing signals that occur when the carriage 109 has reached a desired position. In the present invention, use of a FLIGHT_TIME_REGISTER 203 compensation enables the production of firing signals at a programmable time before the carriage 109 reaches the target position to compensate for the time that it takes a fired ink drop to reach the print medium and the x-axis velocity imparted to a fired ink drop by the carriage 109 . An apt analogy would be the dropping of a free-fall bomb prior to the airplane actually being directly over the target. While an EXPECTED_FLIGHT_TIME (“EFT” hereinafter) as measured in system clock cycles could be used as the input signal, in order to compensate for paper shape changes, the input is dynamically derived in a Paper Shape Compensator 400 as shown in FIG. 4, with the methodology of operation shown in FIG. 5 .
Paper Shape Compensation
A piecewise linear approximation to actual paper shape is generated as schematically depicted in FIG. 6, where the view is looking into the printer along the y-axis. The paper shape compensator 400 is implemented by using the minimum time unit used to describe ink drop flight time. In general, a flight time change can be implemented as a simple, programmable incrementer/decrementer. The circuitry that determines if the flight time is updated is implemented by using a simple re-loadable, down counter that counts down at each decision interval, viz. the time it takes the carriage to move {fraction (1/150)}th inch in this exemplary embodiment. When the counter counts down to zero, the flight time is either incremented or decremented and the counter is re-loaded with the programmable value. The programmable value correlates to the rate at which the pen to paper spacing is changing. The flight time is incremented if the spacing is increasing and is decremented if the spacing is decreasing. The profile is generated as a piecewise linear approximation of actual contouring of a sheet of media on the printing station platen of the hard copy apparatus.
Before the start of a carriage sweep, all registers of the paper shape compensator 400 are initialized, step 501 , FIG. 5 . Paper shape, i.e., linear approximation segment slope and sign, parameters are then updated on Carriage_Position_Interrupts, “ExtPos,” that is, whenever the carriage passes a pre-programmed {fraction (1/150)}th inch position along the x-axis. Firmware selects the {fraction (1/150)}th-inch position of the ExtPos interrupt by writing the Position into an Interrupt Position register 230 . A comparator 231 generates an interrupt when that position is reached., Scanning_Position_Interrupt. In FIG. 3, ExtPos corresponds to Position, which changes at every Edge, viz. {fraction (1/150)}th- inch. Thus ExtPos changes at every FTP_Count. Any number of linear segments can be used. Four parameters are maintained in respective registers: Freq_Reg 401 , Mult_Reg 402 , Slope_Reg 403 , and Flight_Time_Reg 203 (preferably, the first three registers 401 , 402 , 403 are actually coded into a single register to minimize system delay), FIG. 4 . When the first three registers 401 , 402 , 403 are first set, the Expected_Flight_Time value for the start of the print zone is set in the Flight_Time_Reg 203 . Thus, the decision to perform changes and the actual changes are made as the carriage 209 passes each {fraction (1/150)}-inch position during a scan of the x-axis after the print zone is entered.
The Freq_Reg 401 determines how often the Flight_Time_Register 203 is updated once the Print-Zone has been entered, step 503 . When the carriage 209 is passed either edge of the Print-Zone, a frequency decrementer, Freq_Dec, 405 is loaded with the with content of the Freq_Reg 401 , step 505 . In the Print-zone, steps 507 , the value is decremented at every {fraction (1/150)}th inch until it reaches zero, triggering the next stage. Note that when the Freq_Dec 405 reaches zero it also causes itself to be reloaded with the value of Freq_Reg 405 again to start timing for the next update, step 509 .
The Mult_Reg 402 stage determines how much to change the flight time parameter in the Flight_Time_Reg 203 . When triggered by the preceding Freq_Reg 401 logic stage, the value of Mult_Reg 402 is loaded, step 511 , into a decrementer, Mult_Dec, 407 . The Mult_Dec 407 counts down to zero and stays there until the next trigger from the Freq_Dec 405 , step 513 . For each non-zero count of the Mult_Dec 407 (step 513 -No path), the value of the Flight_Time_Reg 203 is changed by a count of 1, steps 515 . The plus or minus determination for incrementing or decrementing the Flight_Time_Reg 203 is provided by the value programmed in the Slope_Reg 403 . The Slope_Reg 403 provides a value based on a measurement taken of the distance between a sensor and the paper. The values programmed in the Freq_Reg 401 , the Mult_Reg 402 , and the Slope_Reg 403 are based on mechanism mesurements taken of the distance sensed. [A variety of devices and techniques for the measurement of distance are known in the art. U.S. Pat. Nos. 5,262,797 and 5,289,208 and 5,414,453 and 5,448,269 include exemplary methods and apparatus assigned to the common assignee of the present invention and are incorporated herein by reference. In the present best mode, an actual paper shape profile along the x-axis is generated using test patterns as in the patents cited immediately above. This profiling can be accomplished during product testing during manufacture or, in a programmable implementation by providing each hard copy apparatus with a test mode capability whereby the end-user can generate a profile for the particular print media to be used (e.g., plain paper, photographic quality paper, transparencies, and the like) prior to an actual print job. In a more complex implementation, real time pen-to-paper distance sensing can be used during a scan. Such techniques are all known in the art and within the scope of the present invention paper shape compensation method and apparatus. It will be recognized by a person skilled in the art that a further description of such systems here is not essential to an understanding of the method and apparatus of the present invention.]
The number and position of the carriage position Interrupts is determined by the firmware programming employed for a specific implementation. In a properly designed system, these Interrupts will occur wherever there is a change in the linear approximation of paper shape. Thus, the foregoing process loops continuously until the Print-Zone is exited at which time the update process halts and the firmware can initialize the parameters for the next scan along the x-axis, shown generically as steps 517 . The Flight_Time_Register 203 is potentially updated on any carriage Position (FIG. 3) and additionally enables a Carriage_Position_lnterrupt such that it can be notified when the Freq_Reg 401 , Mult_Reg 402 , and Slope_Reg 403 parameters can be updated to approximate the next paper shape segment.
Note that the described system can be designed alternatively to run without the firmware intervention, but this would require a stack of Interrupt Position and paper shape registers having a stack height to equal the number of linear approximation segments desired. This would require more hardware and would be less flexible.
Carriage Velocity Compensation
Generally, as in the prior art such as in FIG. 1A, the velocity of the pen during scanning is measured by counting clock pulses between encoder edges. The desired spacing of the output ink drops is known based on the resolution of the printer, e.g., 300 DPI, 600 DPI, 750 DPI, et seq. Conceptually, the timing of the drop firing is calculated by dividing the drop spacing by the measured pen velocity:
t drop =DPI÷ v pen (Equation 1).
In practice, the known encoder spacing is divided by the known drop spacing to lead the same result:
EEPD =encoder edge signals/inch ÷DPI (Equation 2).
The inverse gives the number of drop spacings between encoder edges.
1 /EEPD =drops/encoder edge signal =DPEE (Equation 3).
The measured time between encoder edges, t EE , is divided by this value which give the time between dot positions.
t drop =t EE ÷DPEE (Equation 4).
Thus, this value is used to count out drop positions.
The present invention leverages the prior art calculations by dividing the flight time, t fly of the drop by the calculated time between drop positions, t drop . The resultant value represent the number of dot timings by which the current drop firing positions should be backed up to have the drops reach the paper surface at a desired encoder position rather than over-shooting the position:
N t drop =t fly ÷t drop (Equation 5).
This value can also be thought of as a velocity compensation value since the effect is to advance the drop firing by the expected flight time.
As the nozzles on the pen's printhead are actually staggered, fire timing velocity compensation is calculated using the stagger distance. In state of the art printheads, there are typically twenty stagger steps between printed output columns; the calculated flight time correction value can correct a drop position to within a significant fraction of a dot width. Fractional values of the calculation thus can be discarded with no impact on print quality.
Turning back to FIG. 2, the Flight_Time_Reg 203 is shown and is, again, receiving an Expected_Flight_Time signal at the start of each period, in this exemplary embodiment each time the carriage 209 has moved {fraction (1/150)}th inch. This input is then used to extrapolate and predetermine a Flight_Time_Error which is equivalent to the number of FTP_COUNT pulses that a fired drop will travel along the scan axis from the time it is fired until it strikes the paper. Hence, it is also the advance time of firing required to compensate for pen-to-paper distance fluctuations as well as the actual carriage velocity.
Referring to FIG. 2, as in the prior art (compare FIG. 1 A), the encoder signals, EncA and EncB, are input to a decoder 201 ; a Position Counter 205 keeps track of position in the x-axis and the Edge pulse is again used to with a Period Counter 207 , extrapolation divider, “EXTRAP_DIV,” 209 , latch 211 , counter 213 , and register 215 to derive the actual carriage velocity and an Extrapolated_Position pulse stream, “ExtPos.” In the preferred embodiment, the speed of the carriage is thus determined by measuring the number of clock cycles between each encoder edge; four separate counters are used with one each assigned to one encoder edge (EncA rise, EncA fall, EncB rise, EncB fall). When the edge occurs, the counter is reset to a start value of 0001 and the previous value is saved; the counter counts up until the next occurrence of that edge when its count is then saved. The outputs of all four period counters are added to form a continuous running average and the average saved in the Period Counter 207 during every time event. EncA and EncB “EDGE” sequence also indicates whether the current printing is occurring left-to-right or right-to-left.
In the prior art, ExtPos is simply used directly as the current position to determine when a stagged group of nozzles starts to fire in accordance with the FTP pulses. In accordance with the present invention, it is further extrapolated and corrected by the Flight_Time_Error to provide advanced firing. In other words, in the prior art the carriage motion produces firing signals that occur when the carriage has reached an indicated position. The Flight_Time-Register 203 value and its division 217 by a calculated “STAGGER_TIME”—where stagger is known for the particular printhead implementation—produces the Flight_Time_Error that is latched 219 and used in incrementing 221 the Fire Position counter 223 such that the output thereof provides a signal, “ColumnSync,” used in combination with the Fire Timing Pulses at a programmable time before the carriage reaches the indicated position. In essence, the Flight_Time_Error value is the number of printhead nozzle address times that the ink drop will travel along the x-axis from the actual moment of firing to the time it strikes the adjacent print medium. The Flight_Time_Error is also thus a velocity compensation value as encoder edge pulses are substantially instantaneously extrapolated during each scan sweep regardless of velocity fluctuations and carriage acceleration/deceleration zones at each side of the print zone.
It will be recognized by a person skilled in the art that the Expected_Flight_Time input written to the Flight_Time_Register 203 can be an average drop flight time as measure in system clocks rather than as calculated in accordance with the circuit and method disclosed in FIGS. 4-6. Thus, in a printer 101 which essentially guarantees that the print media is truly flat, the paper shape compensation logic can be bypassed in favor of a simpler predetermined, preprogrammed flight time constant.
For bidirectional printing, the Flight_Time_Error value is added to the fire position register when the carriage is printing in a first direction, e.g., left to right on the first swath scan, and is subtracted to the fire position register when the carriage is printing in a second direction, e.g., right to left scan.
Note also that as a dynamic system, compensation is automatically adjusted during velocity acceleration and deceleration ramps at each end of the Print-Zone.
FIGS. 7 and 8 are exemplary plots showing the effect of the use of Flight_Time_Error compensation. FIG. 7 is for a print speed of 107-ips and FIG. 8 is for a print speed of 60-ips. In both plots, ColumnSyncK shows where the printhead firing pulse occurs without compensation; ColumnSyncCMY shows where the printer fire with a determined 50-microsecond compensation based on the programmed value in the Flight_Time_Register 203 .
The system as explained hereinabove compensates for the time that it takes each fired drop to reach the paper, compensating for variations in pen-to-paper distance and carriage velocity changes. As the flight time compensator takes the current carriage position at, e.g., {fraction (1/150)}th inch and combines it with the extrapolated position between the {fraction (1/150)}ths of position 00 through EXTRAP_DIV minus one (see FIG. 3 where EXTRAP_DIV=99), the estimated current carriage position is accurate to one pen address time, or stagger. The ink drop thus hits the intended target pixel without any substantial offset.
The foregoing description of the preferred embodiment of the present invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form or to exemplary embodiments disclosed. Obviously, many modifications and variations will be apparent to practitioners skilled in this art. Similarly, any process steps described might be interchangeable with other steps in order to achieve the same result. The embodiment was chosen and described in order to best explain the principles of the invention and its best mode practical application, thereby to enable others skilled in the art to understand the invention for various embodiments and with various modifications as are suited to the particular use or implementation contemplated. It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents. | The present invention provides a method for compensating for the velocity variation in an ink-jet pen by dynamically varying the ink drop firing timing as a function of pen velocity. This makes it possible to print while the pen is accelerating or decelerating without affecting image quality. Scanning velocity change compensation is dynamically and continuously updated at a rate equal to or greater than an encoder edge rate. Further, the present invention provides a method for improving ink drop positioning accuracy across a print media scan by compensating for the change in ink-drop flight time as printhead-to-paper distance changes. Ink drop flight time error is dynamically compensated such that a fired droplet of ink hits its intended target pixel without any appreciable error. | 1 |
BACKGROUND OF THE INVENTION
This invention relates to a method for dispatching air passengers between their arrival in an arrival zone and the boarding of an airplane, with check-in baggage checking and transportation from the arrival zone to an aircraft standing at the ramp, and an airport installation and vehicle suitable therefor.
Air passengers are presently dispatched so that the air passengers arrive at an arrival zone at the airport building and walk with their luggage through the airport building until they arrive at the check-in window or the baggage check-in counter. Even these two facilities may be at a distance from each other. Depending on the design of the airport, passengers are given a boarding pass at the check-in window which is surrendered at the entrance to the waiting room. In more modern airports, the check-in window is directly at the entrance of the waiting room. After passing through security checks, the air passengers remain in the waiting room for a certain time and are then loaded into buses and driven to airplanes waiting at the ramp or pass via telescopically extendable, covered walkways directly from the waiting room to an aircraft which has been taxied close to the waiting room building. In the meantime, baggage is being loaded on baggage vehicles, is taken to the aircraft and is unloaded there again and loaded into the aircraft.
All these operations require separate technical facilities and premises, all of which leads to the situation that modern airport installations require an enormous amount of money and that furthermore, boarding an aircraft is a time-consuming and disagreeable activity as compared, for instance, to boarding a train.
It, thus, is an object of the present invention to accelerate and simplify the dispatching procedure.
SUMMARY OF THE INVENTION
According to the present invention, this problem is solved by the provision that the air passengers are conducted, after they arrive in the arrival zone, together with their baggage, to a vehicle which contains the facilities for checking-in and receiving the baggage; and the check-in and, if required, the security checks take place in the vehicle which transports the air passengers directly to the aircraft.
This method is a departure from the customary dispatch, in which the air passengers pass through different stations, which may be far apart, in a stationary airport building. All these stations or facilities are relocated into the vehicle, so that the air passenger, for normal dispatch, does not enter the airport building at all any more. The vehicle does not make the airport building completely unnecessary; for an extended stay at the airport which occurs due to waiting times when changing airplanes or by similar circumstances, suitable facilities will have to be provided as before. The same applies to the technical facilities which are still provided in an airport apart from those for dispatch of passengers. The long walks in the conventional airport building, however, are eliminated because the required processes take place, in compressed form, in the vehicle which contains windows for checking-in and the necessary electronic facility for checking and possibly changing of reservations, as well as cabins and equipment for security checks.
The separation of the passenger from his baggage is eliminated, which in the conventional airport installation, required extensive organizational arrangements as well as in many cases, time-consuming intermediate processes as well as identification of the baggage to be loaded directly at the aircraft in order to prevent pieces of luggage containing bombs from being smuggled into the aircraft. With the present invention, the air passenger and the baggage carried by him remain together from the time of arrival at the airport until boarding of the airplane.
The check-in and possibly, the security checks can be performed during the waiting time of the vehicle which is necessary for the boarding of the air passengers in the arrival zone, during its travel from the arrival zone to the aircraft and still even during the time of changing from the vehicle to the aircraft. These times therefore are not added to the stay of the air passengers in the vehicle as is the case in the conventional ramp transport, but run in parallel.
An important point is also the absence of a connection between the arrival zone and the air strip proper. It is frequently the case that the conventional airport building must be connected via separate feeders from a nearby traffic station. Even if passengers arrive at the airport in their own motor vehicle, the walks from the extensive parking lots for which frequently no space is available in the immediate vicinity of the airport building or the air strip, can be rather long.
With the present invention, all this does not matter. The arrival zone can be provided at any distance from the airfield. It may be located near the parking lot or at an otherwise suitable area which is not as far from the airfield itself. The air passengers can be transferred directly from there to the aircraft, having been properly dispatched, without entering an airport building itself. Of course, it is also possible to transfer the air passengers from different arrival zones so that all the passengers need no longer be funneled through the central bottle neck of a conventional airport building.
The present invention is not tied to a given size of airport installation, as far as the number of air passengers is concerned. Special advantages, however, are obtained with the present invention in smaller airports to be built because it does away with the necessity to construct extensive stationary building facilities.
The well-known ramp buses are not suitable for the purposes of the present invention because they are designed to serve exclusively for transporting already dispatched air passengers from the waiting rooms to the airplane standing at the ramp. The dispatching has taken place in the stationary airport building. Proper facilities are not found in the ramp bus.
The present invention also relates to an airport facility suitable for carrying out the dispatching method described, as well as a corresponding vehicle.
The vehicle comprises a cabin for the air passengers and the necessary facilities. In general this will be a trackless rubber-tired vehicle.
Preferably, the cabin should have a capacity for accommodating at least a substantial part of the air passengers of an airplane. Considered is for instance, a capacity of about 200 air passengers. For large airplanes, it may be necessary to operate two vehicles in series or in parallel.
The preferred embodiment of the vehicle has a cabin with two stories. The lower story has an entrance accessible from the ground, while the exit in the upper story may be brought into direct connection with the entry of the aircraft, optionally via an adjustable staircase. It makes the vehicle self-sufficient with respect of transferring the air passengers from the ground level in the arrival zone up to the aircraft entrance which is usually located at some height, i.e., no special ramp ladders or similar devices are needed any longer. The air passengers board the lower story themselves, change from the lower story to the upper story within the vehicles and leave the upper story toward the aircraft entrance substantially at the same height.
Having the check-in windows extending along the middle of the lower story, and a set-down zone for the baggage designed as a longitudinal conveyor arranged on the longitudinal outer side of the vehicle opposite the access side of the check-in windows makes it possible to save the effort of reloading the baggage from the check-in point to the airplane. The air passengers set down their baggage in the vehicle whereupon it is reloaded directly from there into the aircraft.
Advantageously, the device for checking in, provided in the cabin, contains in the usual manner, display equipment for checking the reservations and optionally, also a device for storing other reservation actions.
This equipment may be connected via radio to the central data processing installation of the airport; the radio transmission system need have only the limited range of the maximum distance of the vehicle from the airport building.
With a cabin which has two stories, and a check-in facility in the lower story and opposite the entrance a stairway or an elevator for transferring the air passengers from the lower to the upper story, the air passengers, after boarding the vehicle, pass check-in windows and subsequently move over to the upper story of the vehicle. Thus, on the second story there are only dispatched air passengers who do not have to be checked further and can board the aircraft immediately without having to overcome accident-promoting intermediate stations such as stairs or the like.
By placing the compartment for the security check of the air passengers and the carry-on baggage in the only passage to the upper story, no air passenger can therefore get to the upper story and into the aircraft without having passed through the compartment for the security check. Also, leaving the upper story is possible only via this compartment and can therefore be prevented with high certainty.
A cabin which contains the necessary facilities and can accommodate a number of passengers in the order of about 200 naturally has a certain size. A weight in the order of about 40 tons can be expected.
The use of a container transporter chassis permits designing such a cabin economically in the form of a vehicle.
Container transporters are portal-like vehicles with two lateral longitudinal girder structures, at the underside of which supporting wheels are arranged front and back, at least one pair of wheels being steerable about a vertical axis. The equipment can be self-propelled, in which case the drive is arranged on the longitudinal structures or in a transverse region located above the free portal space.
The container transporters can be driven over a container, or several such containers stacked on top of each other, located on the floor or a low-slung road or track vehicle, and can lift them by means of a lifting device. The container hanging in the free portal space is then driven to the desired point. In view of the possible weight of one or more containers with the customary dimensions, container transporters are capable of carrying considerable loads of just the order of magnitude of interest here. A cabin supported by a container transporter chassis allows making use of the available technology of these vehicles so that the remaining design effort consists only of integrating the cabin into the vehicle chassis in a suitable manner.
This goal is achieved with a cabin supported by a container transporter chassis, the supporting longitudinal girders of the container transporter chassis being bridged by transverse members which extend between the stories at the height of the ceiling or floor, and support the cabin. This arrangement allows suspending the lower story from the transverse members while the upper story is placed thereon. The transverse members therefore do not interfere because they are arranged in the region of the separation between the upper and the lower story but not transversely through one of them.
If an available container transporter is to be used without changes in design, the width remaining between the longitudinal girders or the wheels may be too small for the purposes of the present invention. In that case the cabin supported by a container transporter chassis with a part of the cabin provided in the transverse direction between the wheels of the container transporter chassis and another part laterally outside thereof may be used.
Like most container transporters, the vehicle may be self-propelled. However, a trailer pulled by an auxiliary vehicle also falls within the scope of the present invention.
In a further embodiment, the vehicle is supported on a self-supporting and self-propelled, substantially horizontal frame under which several wheel sets are arranged in a well-known manner. The wheels can rotate 360°, controlled in mutual dependence, and the frame comprises two lateral frame girders extending in the longitudinal direction. A lower story of the cabin is suspended between the frame girders while the upper story is supported on the frame girders.
Vehicles with a substantially horizontal frame, under which several individually driven wheel sets are arranged which can be rotated 360°, controlled with mutual interdependence, are known from the field of heavy-duty transport vehicles. The frame is formed here by a platform on which the load can be placed. Also the driver's cabin is mounted under the platform so that no parts of any kind protrude upwards above the platform. If the wheel sets are aligned parallel to each other in the lengthwise or transverse direction, the vehicle executes movements in these directions. However, any other curve radii can also be negotiated, the steering angles of the individual wheel sets of the vehicle being automatically adjusted by the steering mechanism depending on their distance from the respective center of the curve. Such a vehicle therefore has extraordinary maneuverability and, because of its substantially flat topside does not interfere with the design of a cabin supported thereon.
In order to save overall height, an embodiment in which the vehicle has one story and has areas extending laterally beyond the track width may be used. The frame, of course, has of necessity a certain height which, with the embodiment given, can be utilized by accommodating part of the cabin between the frame girders.
However, the vehicle need not necessarily have several stories. In some cases such a design may even be impossible, for instance, if the vehicle must travel under existing building structures or through tunnels which have limited clearance. In such cases, the vehicle may have one story and areas extending laterally beyond the track width, with the floor of the cabin disposed at so low a height above ground that it can be reached via at most three steps. Additional space is gained by parts of the air passenger cabin arranged outside of the track width. This embodiment is not tied to a given design of the chassis.
To save stairs or elevators which are always an obstacle and are inconvenient and accident-provoking for the air passengers, the cabin can have at least one seating arrangement for the air passengers which rises in several steps and comprises several rows of seats which are higher toward the outside and extend in the longitudinal direction of the vehicle at the side wall thereof. This design of the seating arrangement not only gives the air passengers a better view of the proceedings in the cabin and contributes to quieting them down, but permits, on the other hand, ready surveillance of the air passengers by the airline personnel, for instance, for counting the passengers in preparation for the start.
In a further aspect, it is an object of the present invention to decrease, in the case of trackless vehicles, the problems due to the tires, and at the same time, to simplify steering.
This problem is solved by an airport layout having track-bound vehicle and a track system for the vehicle which passes by the arrival zone as well as by the ramp in the immediate vicinity of the aircraft. By using track-bound vehicles, all expenditures for steering are eliminated which can be substantial, considering the size of the vehicles. The track installation runs from the arrival zone to the ramp along a suitable path which has the necessary stations for receiving passengers The airplanes occupy fixed positions which the track installation passes directly. Experience with the conventional terminals, in which the aircraft docks directly, shows that there are no problems if the aircraft occupy fixed positions.
This idea is embodied not only in the airport layout but also in the corresponding vehicle which can also be equipped with wheel sets which allow travelling over the track installation as well as running on a trackless travel surface, i.e., for instance, a road-like path or the ramp.
In airports, in which the airplanes roll directly to the waiting room building, towing vehicles are furthermore necessary which push the aircraft which, of course, cannot go backwards, from the position directly at the waiting room building, into a roll-off position at some distance from this building from which the aircraft can roll with its own propulsion and can continue to roll to the air strip.
It is a further object of the invention also to replace the towing vehicles by devices requiring a smaller expenditure.
According to the present invention, this problem is solved by the provision that the aircraft at the ramp is towed by the vehicle.
The vehicle provided according to the present invention therefore largely takes over not only the functions of the conventional airport building but also part of the functions of the ramp facilities.
While in general, the towing of airplanes away from waiting rooms will not be under consideration because these waiting rooms are eliminated by the system of the present invention, there are enough situations in an airport adapted to the new system especially in a smaller airport, where towing an aircraft is advisable or has advantages as compared to the case that the aircraft travels with its own propulsion which always necessitates certain turning radii and empty space behind the aircraft because of the jet.
Thus, the vehicle has a coupling device by means of which it can be coupled to the aircraft in order to tow the aircraft.
Such coupling devices are known from conventional towing vehicles They usually comprise a coupling rod attached thereto which engages the front wheel of the aircraft.
Since the vehicle according to the present invention is taller than the conventional towing vehicles and cannot travel under the nose of an airplane, the coupling rod will usually have to be longer than usual.
It is therefore advisable that the coupling rod be arranged so that it can run under the vehicle for stowage so that it otherwise does not interfere with the operation of the vehicle.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the vehicle at an angle from the front.
FIG. 2 is a side view of the vehicle with somewhat changed proportions.
FIG. 3 is a view according to FIG. 2 from the right.
FIG. 4 is a view according to FIG. 2 from the left.
FIG. 5 is a cross section according to the line V--V of FIG. 8.
FIG. 6 is a cross section according to the line VI--VI of FIG. 8.
FIG. 7 is a top view of the upper story.
FIG. 8 is a top view of the lower story.
FIG. 9 is a vertical section through a vehicle which is built on a frame with individual steerable wheel sets.
FIGS. 10a, 10b and 10c illustrate schematically the maneuverability of such a vehicle.
FIG. 11 is a top view of a single-storied vehicle.
FIG. 12 is a view of the embodiment according to FIG. 6 from below.
FIG. 13 is a vertical section through an embodiment of the vehicle with rows of seats staggered in height.
FIG. 14 is a top view of the upper story of the vehicle according to FIG. 5.
FIG. 15 is a vertical longitudinal section through the vehicle
FIG. 16 is a view of a vehicle with a coupling device.
DETAILED DESCRIPTION
The vehicle 100 in FIG. 1, comprises a cabin 10 which consists of a lower story 1 and an upper story 2. The cabin is supported by a container transporter chassis 20, of which a longitudinal girder 21 with air-tire wheels 22 mounted underneath can be seen in FIGS. 1 and 2. One set of wheels 22 is steerable. The container transporter chassis 20 has a propulsion motor 23 which is arranged on the longitudinal girder 21. The vehicle 100 is operated from a driver's cabin 3 which is mounted on the front of the vehicle. The entrance 4 to the cabin 10 is located in the lower story 1 on the back side of the vehicle 100, while the exit 5 is located in the upper story next to the driver's cabin. At the exit 5, a staircase 6 is provided, the height of which can be adapted to the different height levels of the entries of the airplanes and facilitates the passing of the air passengers from the upper story 2 directly into the entrance of the aircraft.
It can be seen in FIG. 3 that the cabin is wider than the container transporter chassis 20. For, the right-hand wheels (as seen in the travel direction) 24 of the latter are not on the right hand side of the cabin 20, but in the interior thereof, as shown in FIG. 3. Through the one-sided overhang, a relatively large additional unimpeded space is gained in the lower story in the cabin 10, as can also be seen in FIGS. 5 and 8
The door 7 on the front of the vehicle, shown in FIG. 4, is closed to the normal air pasenger traffic and is used only for discharging the baggage from the deposit area 17 (FIG. 8).
As can be seen from FIG. 5, the two longitudinal girders 21 and 25 of the container transporter chassis are bridged by transverse members 26, on which the upper story 2 is placed and from which the lower story 1 is suspended. The lower story 1 comprises a part 1' between the longitudinal girders 21 and 25 and a part 1" arranged laterally outside thereof. The wheels 24 arranged in the interior of the cabin 10 are accommodated in special fenders 27 (see also FIG. 8). The space 28 remaining between the wheels 24 under the longitudinal girders 25 can be utilized as can be seen from FIG. 6.
In FIG. 7, a top view of the upper story 2, which the air passengers reach via a staircase 8 is shown. They then arrive in an area 9 for a security check. There, the air passengers and, if required, the carry-on baggage are examined for carried-on weapons, and if necessary, passports are checked. This is done at the passages 11. The air passengers can subsequently remain in the upper story where, of course, seating, not shown, is provided. When they reach the aircraft, the air passengers can change to the aircraft immediately from the exit 5 via the stairs 6.
As shown in FIG. 8, the air passengers enter the cabin 10 at the entrance 4 and get into a hallway 12 which extends in the longitudinal direction and on the left side of which a bench 13 for sitting or setting down baggage may be provided. Along the middle of the lower story 1 the check-in windows 14, which comprise the customary data display equipment 15 or a complete reservation data terminal, extend. This equipment is connected via radio to the central data processing installation of the airport in a manner not shown. Between the check-in windows 14, baggage conveyors 16 are provided which run in the transverse direction and transport baggage from the side of the hallway 12 to the side opposite the check-in windows 14, where it is transferred to a deposit area 17 which advantageously is likewise designed as a conveyor and is capable of transporting the baggage through the door 7 in the direction of the arrow 18. The deposit area 17 can also be designed as a roller track or in a similar manner so that the baggage can be automatically pushed together tightly. The baggage transported out of the door 7 is picked up over on the outside by a further conveyor device which passes it on directly into the baggage space of the aircraft.
As mentioned, the air passengers enter the lower story of the cabin 10 at the entrance 4, are dispatched at the check-in windows 14 at which time the baggage may be transferred to the deposit area 17, change to the upper story 2 via the staircase 8, pass through the security area 9, and then gather in the upper story 2. After leaving the passages 11, the air passengers are completely processed and can move into the aircraft without further checking. They also cannot leave the upper story 2 any more because they were registered in the compartment 9. The entire dispatch and checking of the air passengers can take place during the entering time into the vehicle 100, during the latter's trip to the aircraft and even during the disembarking time of part of the passengers at the aircraft itself.
For disembarking, the travel of the air passengers is, of course, in the opposite direction.
The vehicle 200 in FIG. 9 comprises a cabin 110 which consists of a lower story 101 and an upper story 102. The cabin 110 is supported by a chassis 120 and comprises two frame girders 121 which are opposite and parallel to each in the other in the longitudinal direction in a horizontal plane, and under which individually steerable and driven wheel sets 122 are mounted. The steering excursions of the individual wheel sets 122 is accomplished via a central control which coordinates the steering excursions and coordinates, when negotiating a curve, in dependence on the distance of the individual wheel set 122 from the respective center of the curve. The steering is done by a driver in a driver's cabin 123 which is likewise attached under the platform represented by the frame girders 121.
The upper story 102 rests on the top side of the frame girders 121, while the lower story is suspended between the frame girders 121. It extends into the upper story 102 by a certain amount. The space lost thereby in the upper story 102 is regained by a corresponding inclined design of the roof 124.
The passengers enter the lower story of the vehicle 200, deposit their baggage 125 on the corresponding conveyor belts 126 extending in the longitudinal direction of the vehicle, and are processed at the windows 127. They then walk into the upper story 102 via a staircase, not shown, in the process of which the security checks are made. During the trip until entering the aircraft, which is accomplished via a bridge leading directly to the entrance door of the aircraft, the passengers stay in the upper story 102.
In FIGS. 10a, 10b and 10c, the distribution of the wheel sets 122 over the chassis 120 is shown. The vehicle 200 is indicated by its outline 128.
The wheel sets are distributed symmetrically over the underside of the frame 120. In the embodiment of FIGS. 10a, 10b and 10c, each wheel set 122 has twin tires on both sides of the vertical axes of rotation 129 (FIG. 9), while only single tires are provided in FIG. 9. A total of 6 wheel sets 122 is attached in tandem to each frame girder 121, the wheel sets of the two frame girders 121 being opposite each other in the transverse direction. The number of wheel sets is not mandatory but depends on the size of the vehicle 200 and the carrying capacity of the wheels used.
In FIG. 10a, the individual wheel sets 122 are set so that the vehicle 200 can negotiate a curve, the center of which is located below FIG. 10a. All wheel axles go through the center of the curve. The axles can be relocated anywhere, so that the vehicle 200 can negotiate very narrow curve radii and even can turn on the spot.
In the example according to 10b, the vehicle as a whole executes a movement at an angle, and in the example according to FIG. 10c, executes transverse travel. All these possibilities are set by the central control in response to operation of the steering wheel in the cabin 123. The location of the support points of the chassis 120 is not changed thereby, so that the stability of the vehicle 200 is not affected by the state of the steering.
The individual wheel sets 122 are driven electrically or hydraulically.
In the vehicle 300 of FIGS. 11 to 13, the cabin is supported by a container transporter chassis 220 and of which the longitudinal girders 221 with the air-tire wheels 222 mounted underneath can be seen in FIGS. 11 and 13. The vehicle 300 is operated from the driver's cabin 203 which is attached to the front of the vehicle 300. The entrance is located in the lower story 1, while the exit 205 is provided in the upper story 203. The exit 205 can be adapted by suitable measures to the different height levels of the entrances of the aircraft, for instance, by a ramp or bridge adjustable in height, in order to make possible the passage of the air passengers from the upper story 202 directly into the entrance of the aircraft.
The air passengers are processed at the windows 214 and arrive, if necessary, after security checks are performed, via the staircase 201, in the upper story 202, where they can be seated on rows of seats 209 which extend along one side wall of the vehicle and are staggered in height, so that the outer rows of seats are arranged highest.
The vehicle 400 of FIGS. 14 and 15 has a cabin 310 which has only one story. The floor 301 of the cabin 310 is close to the ground level 302, so that entering is possible by means of only two steps 303. Parts 306 and 307 of the cabin 310 are arranged outside of the track width defined by the wheels 322, so that the vehicle is very wide. The entrance 304 and the exit 305 are side by side at the same height. For boarding the aircraft, a separate boarding ladder is therefore required. Instead of the exit 305, a bridge or ramp rigidly connected to the vehicle 400 can, of course, also be provided for direct entrance into the aircraft.
The processing takes place at the windows 314, and the security check in the area 309. The air passengers stay in the rows of seats 315. The baggage deposit 317 is located at the side walls.
The vehicle 400 is not self-propelled but is towed by a tractor 320.
The vehicle 100 of FIG. 16 corresponds substantially to the embodiment according to FIGS. 1 to 8 and, to this extent, carries the same reference numerals. The staircase 6 is folded up in FIG. 16 because in the operating condition shown, the boarding of the air passengers is already completed.
Under the floor of the lower story 4, a coupling device 524 is attached and comprises a coupling rod 525 which can be run forward from under the vehicle 100 in the direction of the arrow 526 and can be retracted under the vehicle. At the front end, the coupling rod 525 has a coupling pin 527 which engages a corresponding device at the front wheel set 528 of the aircraft 530. In this manner the aircraft 530 can be pushed or pulled by means of the propulsion of the vehicle 100. | A method, and a vehicle for dispatching air passengers between the arrival at an arrival zone and boarding the aircraft, with check-in, baggage checking and transport from the arrival zone to the aircraft waiting at the ramp, in which the air passengers, after arriving at the arrival zone, are conducted, together with the baggage, into a cabin mounted on a vehicle, and check-in, baggage checking and, optionally, a security check are performed in the cabin which transports the air passenger directly to the aircraft. The vehicle, thus, takes over a number of functions which heretofore were performed in the stationary airport building. The dispatching takes place simultaneously with the transport of the air passengers to the aircraft. | 1 |
BACKGROUND OF THE INVENTION
The present invention relates to a method and device for assessing the viability, in other words vitality, of intact teeth, and more particularly to a device and method for assessing the amount of blood in a tooth of a patient based on the ratio of transmission of light of at least two wavelengths.
A well known problem in conventional dentistry is the determination of changes in vitality of a tooth which remains intact in the mouth of a patient. As a patient ages, a tooth can gradually or suddenly lose its circulation of blood, and at some point can essentially become a dead tooth. Although such a dead tooth can continue to function as an intact tooth indefinitely, on the other hand, problems can arise once the tooth loses its vitality and approaches the status of being dead. In any case, it is of interest to the dentist, and certainly to his patient, to be aware of any changes in tooth vitality, even when the change is occurring slowly.
A current clinical method of assessing tooth vitality is to electrically stimulate the tooth, to see if the patient can sense the stimulation. This method has two disadvantages. First, it is limited to the patient's ability to localize the sensation, and second, the presence of irritability does not necessarily indicate that the tooth has intact circulation. Other prior art has involved the use of light for detecting the condition of teeth or for detecting the presence of blood in human tissue. For instance, Alfano in U.S. Pat. No. 4,290,433 (and see also U.S. Pat. No. 4,479,499) teaches a method and apparatus for detecting caries in teeth using the relative luminescence of teeth at two wavelengths. This involves illuminating a surface of a tooth with short wavelength visible light, and collecting the light received back from the surface at longer wavelengths. The spectrum of the received light depends on the extent of the caries or decay which is present on the surface of the tooth. Wilber in U.S. Pat. No. 4,407,290 involves detecting in human tissue a pulse of a varying constituent of flowing blood. Others have sought to measure fluorescence illuminisence in tissue or in the breath of a person (U.S. Pat. Nos. 3,811,777, 3,725,658 and 4,178,917), or to measure optical density in tissue to estimate its dimensions (U.S. Pat. No. 3,648,685, 3,674,008), to map an image of the surface of an object (U.S. Pat. No. 4,564,355, 4,575,805, 4,170,987), or to measure surface color (U.S. Pat. No. 3,709,612, 2,437,916). Prior art efforts in the fields of egg-candeling have addressed the problem of detecting blood in eggs, and pulse oximetry has involved use of different wavelengths for determining relative amounts of oxyhemoglobin and reduced hemoglobin in blood. Photo-plethsmography involves techniques for assessing blood flow. Such prior art is directed to entirely different fields of use and involves determination of different physical properties using different devices and methods as compared to the present invention. None of these prior art techniques involve devices or methods which are available for or suggest assessing viability of intact teeth.
SUMMARY OF THE INVENTION
The present invention is directed to a fixturing device and method for assessing the vitality of intact teeth, based on the presence of hemoglobin in blood therein, as affecting the value of a ratio of intensity of light of at least two wavelengths traversing the tooth. Light in the context used in the present invention is meant to include electromagnetic radiation which need not be limited to the visible spectrum.
The present invention is directed to a device which is easily inserted into the mouth of a patient, to allow for convenient assessing of the viability of his teeth.
The device and method allow predicting whether a single value for the ratio indicates the tooth is viable or not.
The device and method allow establishing a baseline for each tooth of a patient, so that any changes from the baseline that are detected in successive visits by a patient to his dentist can be easily determined.
The device and method are further directed to easily and conveniently allowing a patient and his dentist to monitor the vitality of the patient's teeth.
The invention allows assessing tooth viability by simply forming the ratio of transmitted light of different wavelengths.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1a shows the absorption spectrum of deoxyhemoglobin for the region of 500 nm to 800 nm.
FIG. 1b shows the absorption spectrum of oxyhemoglobin for the region of 500 nm to 800 nm.
FIG. 1c shows the combined absorption spectra for oxyhemoglobin and deoxyhemoglobin for the region of 500 nm to 800 nm.
FIG. 2 shows an embodiment of the device of the present invention, including a fixturing device placed around a tooth, and optical fibers and analyzers.
FIG. 3 shows the absorption spectra of a tooth which is devoid of hemoglobin for the region of 500 nm to 800 nm.
FIG. 4 shows the expected percentage change in signal for a tooth which goes from havingnormal circulation to having to hemoglobin when the ratio measured is for 575 nm to wavelengths from 580 nm to 800 nm.
FIG. 5 shows the expected percentage noise of the measurements as a function of wavelength from 580 nm to 800 nm.
FIG. 6 shows the expected signal-to-noise ratio as a function of wavelength when the first wavelength is selected at 575 nm.
FIG. 7 shows the resulting change in the measured wavelength ratio for six teeth as they go from a state of normal blood content to a state of no blood.
FIG. 8 shows the general concept of a ratiometric system for measuring hemoglobin in intact teeth, wherein a wedge filter is used in determining relative intensities at two or more wavelengths.
FIGS. 9a to 9i show different embodiments of the optical fibers and fixturing device.
DESCRIPTION OF PREFERRED EMBODIMENTS
The present invention employs the relative transmittance of light through a tooth, for example in the visible and near infra-red, as a result of relative absorption by hemoglobin in blood in the tooth. FIGS. 1a and 1b show the absorption spectra in the visible and near infrared region for deoxyhemoglobin and oxyhemoglobin, respectively. FIG. 1c shows a linear combination of these absorption curves, corresponding to equal amounts of the two types of hemoglobin being present. The curves are adapted from D. L. Horecker, "The Absorption Spectra of Hemoglobin and its Derivation in the Visible and in Infra-red Regions", J. Biol. Chem, Vol. 48, pp 173-184, 1943. These are the two main constituents of normal circulating blood and are of primary significance for determining tooth vitality according to the present invention.
FIG. 2 shows an adjustable fixturing device 1 having portions on both sides of the tooth in the gum of a patient's mouth. This adjustable fixturing device 1 allows light from the light source 2 to be incident via optical fibers 3 onto the tooth. The purpose of this incident light is simply to flood the tooth with the incident light. It is not necessary that the incident light be supplied to the tooth on the opposite side from where the optical fibers 4 receive the light scattered by the tooth. The optical fibers 4 divide to provide separate inputs to respective filters 5. Each filter 5 passes a respective wavelength from the light collected from the tooth, and optical detectors 6 provide outputs corresponding to the amount of light passed by each filter. The ratio circuit 7 electronically divides one signal into the other, and outputs a signal indicating the ratio of the intensities of the received light at the two wavelengths. A broad band source can be used for the light source 2, without excessive concern for its stability, in view of the ratio of the two wavelengths from the light source that is measured as a result of the filters 5, optical detector 6 and the electronic divider 7. Collimators, not shown in FIG. 2, can be provided before the filters 5.
FIG. 1c shows a pronounced absorption peak for the combined spectra at a wavelength of approximately 585 nm. The amount of absorption in this vicinity of wavelength will depend particularly upon the presence of hemoglobin in the pulp of the tooth.
FIG. 3 shows the absorption spectra of a tooth which contains no blood. White light passing through a tooth which contains blood will be absorbed in a manner determined by a combination of the absorption spectra such as of FIGS. 1c and 3. White light passing through a tooth which contains no blood will be absorbed in a manner determined only be the absorption spectrum of FIG. 3. Thus the ratio of light at two wavelengths will be different for a tooth containing blood and a tooth without blood. The percentage change of the ratio of a tooth with blood to a tooth with no blood will be the expected signal for any given ratio of wavelengths.
FIG. 4 shows the expected signal change when the first wavelength is selected at 575 nm and the second wavelength varies from 580 nm to 800 nm. This expected signal change is based on a linear combination of the absorption spectra of FIGS. 1c and 3. Further study may reveal that a linear combination of these two spectra is not the best method for representing the absorption behavior of the tooth. While this will result in a change in the shape of FIG. 4, the method for selecting optimal wavelengths described herein will still be valid.
The path which the light takes in a tooth depends in part upon the wavelength of the light, since some optical properties of the tooth are a function of wavelength. As the difference between the two wavelengths increases, any error caused by changes in path length resulting from changes in the probe position from measurement to measurement can be generally expected to increase.
A test was conducted in which white light emitter from the light source 2 was conducted along an optical fiber 3 to the tooth. The incident white light entered the tooth, where some wavelengths of light were absorbed more than others. Light output from the tooth was collected and connected along the second set of optical fibers 4 to the pair of filters 5, one of which passed light in the vicinity of 575 nm and the other passed light of either 585 nm, or 795 nm. Fixturing device 1 was not employed, so that measurements could be made with the fibers 3 and 4 placed in arbitrary geometrical relationships. A series of ten measurements were made for each of three teeth at each of three wavelengths (585 nm, 655 nm, 795 nm). The results of these measurements are given in Table A.
TABLE A__________________________________________________________________________Experimental determination of the statisticalvariability of measured intensity ratios as a functionof wavelength of the tooth viability detector. Wavelength Ratio 575/585 nm 575/655 nm 575/795 nm M S N M S N M S N__________________________________________________________________________Tooth 1 1.018 .053 5% .470 .049 10% .508 .114A 22%Tooth 2 .983 .062 6% .412 .063 15% .402 .120 30%Tooth 3 .949 .067 7% .428 .066 15% .366 .103 28%__________________________________________________________________________ M Mean of measurements S standard deviation of measurements N S/M × 100 percent variation or noise
The ratio of the standard deviation to the mean expressed as a percentage is taken to be the noise. A curve was fitted to the data of Table A and is shown as FIG. 5. wherein the noise is shown as a function of the second wavelength employed.
The best embodiment of this device will be one in which the signal-to-noise ratio is maximized. The signal-to-noise ratio may be improved by either decreasing the noise or by increasing the signal. A variety of ways can be utilized to achieve such improvement. FIG. 6 shows the signal to noise ratio as a function of wavelength as determined from FIGS. 4 and 5. From this an optimal second wavelength to be used with a first wavelength of 575 nm may be determined. In this case an optimal wavelength is seen to be in the vicinity of 625 nm. A series of curves similar to that of FIG. 6 may be created for any set of wavelengths, so that two optimum wavelengths to be employed may be selected.
A further test was conducted, in which white light emitted from the light source 2 was conducted along an optical fiber 3 to the tooth. The incident white light entered the tooth, where some wavelengths of light were absorbed more than others. Light output from the tooth was collected and conducted along the second set of optical fibers 4 to the pair of filters 5, one of which passed light in the vicinity of 575 nm and the other passed light of 795 nm. Fixturing device 1 was employed so that measurements could be made with the fibers 3 and 4 placed at the same anatomical points on the tooth each time. In this test the noise was found to average 16%, whereas in the test whose results are given in Table A the average noise for these two wavelengths was 27%. Thus it was demonstrated that the use of fixturing device 1 can substantially reduce the noise of the measurements.
FIGS. 4 and 5 represent only the present understanding of light absorption by the tooth. Further study may reveal that curves of different shapes may better represent the nature of the signal and noise. In any case, the maximum ratio of signal to noise will still determine the optimal selection of wavelengths, as demonstrated by FIG. 6.
A further test was conducted, using 595 nm as the second wavelength. White light emitted from the light source 2 was conducted along an optical fiber 3 to be fixturing device 1. The incident white light entered the tooth, where some wavelengths of light were absorbed more than others. Light output from the tooth was collected and conducted along the second set of optical fibers 4 to the pair of filters 5, one of which passed the light with wavelength in the vicinity of 585 nm and the other passed light in the vicinity of 595 nm. The absorption by the tooth of the light near the second wavelength, namely at 595 nm, was less, as a result of absorbing a smaller part thereof. Thus, use of the ratio of the first and second wavelengths is to compensate for the total amount of light passing through the tooth which will change with the intensity of the light and the path of the light through the tooth.
The ratio of intensities of the light at the two wavelengths is a measure of the amount of hemoglobin in the tooth. The value of the ratio of the intensity of the 595 nm light to the 585 nm light is expected to decrease as the amount of hemoglobin in the tooth decreases. This trend was observed experimentally with extracted teeth, the results of the experiment being given in Table B in terms of the inverse of this ratio, namely the 595/585 less absorbtion ratio of the intensity of the 585 nm light to that of the 595 nm light. This shows the ratios of the intensities for these two wavelengths, readings #1 indicating observations on a freshly extracted tooth, and readings #2 and #3 having been made at later times after the hemoglobin had broken down.
TABLE B______________________________________Experimental ratios of tooth viability detector. Reading # #1 (8-29-85) #2 (9-10-85) #3 (9-24-85)______________________________________Tooth one 0.88 0.81 0.83Tooth two 0.94 0.85 0.87Tooth Three 0.98 0.87 0.86______________________________________
The percent change between a tooth with no blood is about 10% as determined by the results of Table B. The noise at these two wavelengths is about 5% as determined by FIG. 5. The signal-to-noise ratio for these two wavelengths would thus be about 2 as is predicted by FIG. 6.
Tests were conducted using this second set of wavelengths on extracted teeth which initially did not contain any blood. Subsequently each tooth was injected with a quantity of blood representative of that which would be found in a healthy intact tooth, and the measurements were repeated. Each measurement consisted of determining the transmitted light ratio 5 times in each of two positions for a total of 10 measurements, for each of 6 teeth. After each tooth was injected with blood, an identical set of measurements was then made, during the time that the injected blood was considered as fresh blood. Following this further set of measurements, the teeth and a sample of the blood were refrigerated, and the blood sample was checked with a spectro-photometer periodically over a period of two weeks, until it was clear that the hemoglobin had broken down into other components not having such absorption. A final set of measurements was then performed. The results are shown in FIG. 7, wherein it is clearly seen that the ratio of the 575 to the 795 nm light decreased with the presence of fresh blood as expected. An analysis indicates that these differences are statistically significant, at a level well above the 99% confidence level. The percent change between a tooth with blood and a tooth with no blood is about 80% as determined by the results of FIG. 7 and predicted by FIG. 4. The noise at these two wavelengths is about 28% as determined by FIG. 5. The signal-to-noise ratio for these two wavelengths would thus be about 2.8, consistent with a prediction based on FIG. 6.
These findings above support the general usefulness of the present invention for assessment of tooth vitality, and further as a means of quantifying change in the circulation of a given tooth over time.
There is a second factor which affects the amount of light absorbed by a tooth. This is the distance the light must travel wighin the tooth, namely from the point where the incident light is provided to where the scattered light is collected from the ratio wavelengths. In the embodiment illustrated in FIG. 2, the fiber optic bundles 3 and 4, as a result of having the relative position of their ends rigidly fixed in the fixturing device 1, deliver and collect the light at well defined points with respect to each other. Thus, the measurements can be repeated on any given tooth with acceptable experimental error, and differences in the value of the ratio between different teeth can be minimized.
A third embodiment of the present invention involves combining in the device and method a third wavelength, for instance at 660 nm. At this wavelength the absorption of oxyhemoglobin is different from the absorption of deoxyhemoglobin. Thus, the ratio of this wavelength to for instance 585 nm can also be formed, in addition to a ratio as above. Forming such a combination of ratios makes possible assessment of the relative amount of oxyhemoglobin present within an intact tooth, by discriminating between the oxyhemoglobin and the reduced deoxyhemoglobin.
The fixturing device can be provided with calibrated adjustment means for locating it in a repeatable fixed position with respect to a tooth. Thus the incident input light and the output light can be repeatedly caused to enter and exit each tooth at the same positions on the surface of the tooth, and along the same direction through a tooth, on successive visits. However, the usefulness of the present invention is not limited in this regard.
The data presented in FIG. 7 show a variability of about 20% for measurements taken on different teeth, whereas the variability expected as shown in FIG. 5 is about 23%. Thus optimal selection of wavelength by the method taught herein as shown in FIG. 6 can result in a device which can assess the viability of a tooth based on a single measurement.
Alternatively, a single wedge filter could be used. The wavelength of light passed by a wedge filter depends upon the point at which light is incident upon the filter and this position could be varied by moving the filter. In this case a single light pipe 4a for the output light is sufficient. This is in fact how the test was performed in which light was measured at 585 nm and 595 nm. A two filter design was considered faster and less sensitive to positioning of the fibers, but there are other ways to overcome these problems which would make a single wedge filter desirable.
A variety of modifications of the fixturing device and optical fiber bundle is also possible. FIG. 9a shows an angled fixturing device for arbitrary geometry of the input and output light fibers. FIG. 9b shows a fixturing device wherein the input and output light fibers are parallel and brought to nearly the same point in a surface of the tooth. FIG. 9c shows a side view of another embodiment, wherein the input optical fiber 3a is combined with the output optical fibers 4b in the vicinity of the tooth. FIG. 9d shows a cross-section of the combined optical fibers 3a and 4b of FIG. 9c where they contact the tooth, wherein an optically opaque divider 11 separates the two respective bundles. The divider 11 can advantageously be provided of a flexible material, to lie against the surface of the tooth to prevent undesired crosstalk of light between the input and output bundles. Alternatively the entrance and exit angles of the light may be arranged so as to prevent direct reflection of the incident light to the detector as shown in FIG. 9i.
When the data was collected using a fixturing device, it was seen as above that the noise decreases. Thus the primary advantage of a fixturing device is to decrease the noise of the measurements and hence increase the signal to noise ratio. There are many ways in which a fixture can be implemented. It can be spring-loaded so as to grab the tooth on two particular surfaces, i.e. the front and back. FIG. 9e shows such embodiment of the fixturing device, which is divided into two parts 1a and 1b connected by an internal spring (not shown) so as to grasp the tooth to hold the fixturing device on the tooth or, it can be shaped like an arc and hooked over the tooth. FIG. 9f shows another embodiment of the fixturing device 1c of a hooking type, with internal fibers. Also, the fibers could be brought to the same side of the tooth, provided direct reflection is prevented, or the fibers could be provided at any desired geometry with respect to each other. Further technical advances or a more specialized design may permit the light source and detectors to be incorporated in the fixturing device.
A bifurcated fiber can be employed to divide the light to the two filters. This could be done with a single fiber which delivered the light to a beam splitter in front of the filters. FIG. 9g shows such an embodiment wherein a bifurcated fiber 4 is replaced with a single fiber and a beam splitter.
Another possibility for improving the noise in the device would be to use monochromatic light sources, such as lasers, for a light source which only contains the two wavelengths of interest. The light exiting the tooth might still have to be filtered, an improvement is to be expected since filters pass light in the vicinity of a given wavelength and not at a single wavelength. While such an approach might be relatively expensive at present, this might change with further technical advances. FIG. 9h shows such an embodiment wherein two monochromatic light sources 2a, 2b of different wavelengths are used with mirrors and a lens to provide the light to the input light pipe 3.
Other arrangements and modifications would be obvious to a skilled worker in the art in possession of the present disclosure. For instance, if imaging is provided for picking up the output light and for controlling the area of input of the input light is incident, then the optical fibers may not need to be in particularly close proximity to the tooth.
Also, it can be seen from the given results that the noise for repeated measurements of the same tooth and measurements of different teeth are of about the same order. This indicates that, if optimal wavelengths are selected as per the method described above, it should be possible to determine the vitality or viability of a tooth based on a single measurement. Thus the device need not be used solely to follow the progression of a tooth with time, but could be used with a single measurement to indicate the current state of a tooth. This is very significant for clinical use of the device of the present invention. | An optical technique and device for assessing tooth vitality, involving the use of trans-illumination to detect differentially the relative absence of light absorbed by hemoglobin in circulating blood inside a healthy tooth. White light received from an illuminated healthy tooth is relatively devoid of intensity at a wavelength characteristic of absorption by hemoglobin, when compared with light following the same path in the tooth but of a longer wavelength, by taking the ratio of intensities of the two wavelengths the light of one wavelength is relatively more absorbed by hemoglobin or oxyhemoglobin than the other, indicating the relative amount of blood or oxygen in the blood present in the tooth at the time of the measurement. A broad-spectrum light source is rigidly coupled to a split-beam, differentially-filtered photometer incorporating relatively narrow band filters. Vitality is assessed from the ratio of the scattered light at the two wavelengths, and in change of this ratio overtime. | 0 |
BACKGROUND OF THE INVENTION
This invention relates to an improved process for making N-alkylpyrrolidones from maleic or succinic derivatives and, more particularly, to processes which reduce maleic derivative using hydrogen to a succinic derivative, or begin with succinic derivative, which derivative is ammonolyzed-alkylated using ammonia and an alcohol to form a N-alkylsuccinimide which is then reduced with hydrogen to form the corresponding N-alkylpyrrolidone.
N-alkylpyrrolidones, in particular N-methylpyrrolidone, are liquid at reasonably low temperatures and because of their powerful dissolving properties have been employed in numerous applications as an extraction and purification solvent. N-methylpyrrolidone has been used in such processes as acetylene recovery from natural gas, butadiene recovery, the separation of aromatics from nonaromatics, sulfur removal from refinery gases, and the dehydration of gas streams. It also has found application as a polymer solvent, being used in the manufacture of resins, fibers, industrial finishes, and in household specialties to overcome incompatibility and improve product performance. Possessing no active hydrogen, it is classified as an aprotic solvent and finds use as a reaction medium in polymer syntheses, for example, alkylated acetylene preparation etc.
Commercially, N-methylpyrrolidone is produced by reacting acetylene with formaldehyde in the presence of a copper acetylide catalyst to generate butynediol. The latter is then hydrogenated to butanediol which is catalytically cyclodehydrogenated to yield 4-butyrolactone. In a final step the butyrolactone is reacted with methylamine to form N-methylpyrrolidone. This technology has several disadvantages. Methylamine and acetylene are both expensive starting materials and the latter presents handling problems as does the formaldehyde. In addition, yields in the four-step commercial process are less than desirable.
Now it has been found that an improved route to N-alkylpyrrolidones starting with a maleic or succinic derivative is available which offers a substantial improvement in process economics because of reduced starting material and processing costs. The improved process is based in part upon the ammonolysis-alkylation reaction of succinic derivatives with ammonia and an alcohol to form N-alkylated compounds.
The thermal reaction with primary amines to form N-alkylpyrrolidones is well documented in the patent literature. See, for example, U.S. Pat. No. 2,643,257, Ger. Offen. No. 2,164,350 and Brit. Pat. No. 1,367,629. In addition, the alkylation of amides and imides via an alcohol is also described. See J Am Chem. Soc 94 679 (1972) and 87, 5261 (1965). For example, phthalimide alkylation to the N-alkylimide has been accomplished in two steps by first making the potassium salt of phthalimide and subsequently reacting it with an alcohol. The use of a combination of ammonia and hydrogen to convert a diethylmaleate/ethanol solution catalytically to 2-pyrrolidone is described by Japanese authors in Y. Kogyo Kagaku Zasshi 73,545 (1970). The catalyst was a nickel or cobalt material. Pyrrolidones have been alkylated catalytically via alcohols to N-alkylpyrrolidones by Japanese workers. See, for example, Japanese Kokai No. 76-16,657. Reduction using hydrogen of succinimide and N-methylsuccinimide to pyrrolidone and the N-methyl derivative has also been extensively reported. See, for example, U.S. Pat. Nos. 3,092,639, 3,745,164 and 3,681,387. Equally, hydrogenation of maleic anhydride and its derivative to pyrrolidone and N-alkylpyrrolidones using ammonia and hydrogen is taught in U.S. Pat. Nos. 3,808,240, 3,198,808 and 3,080,377.
SUMMARY OF THE INVENTION
Described herein is a process to form an N-alkylpyrrolidone wherein said alkyl substituent is selected from the group consisting of methyl, ethyl, propyl, isopropyl and butyl substituents comprising:
converting a compound selected from the group consisting of succinic anhydride, succinic acid, and a dialkyl succinate, where said alkyl is a C 1 to C 4 alkyl group, to a N-alkylsuccinimide by contacting under reaction conditions, optionally in the presence of a catalyst, said succinic anhydride with ammonia and the corresponding alcohol selected from the group consisting of methanol, ethanol, propanol, isopropanol and butanol; and
catalytically reducing said N-alkylsuccinimide with hydrogen to form said N-alkylpyrrolidone.
Also described herein is a process to form an N-alkylpyrrolidone wherein said alkyl substituent is selected from the group consisting of methyl, ethyl, propyl, isopropyl and butyl substituents comprising:
catalytically reducing a maleic derivative selected from the group consisting of maleic acid and maleic anhydride with hydrogen to form succinic anhydride
converting said succinic anhydride to a N-alkylsuccinimide by contacting under reaction conditions said succinic anhydride with ammonia and the corresponding alcohol selected from the group consisting of methanol ethanol, propanol, isopropanol and butanol; and
catalytically reducing said N-alkylsuccinimide with hydrogen to form said N-alkylpyrrolidone.
DETAILED DESCRIPTION OF THE INVENTION
The feedstock for the instant process is maleic acid or anhydride or a succinic derivative such as succinic acid, anhydride, or dialkyl ester. If the process begins with maleic acid or anhydride, the compound, neat or dissolved in a solvent such as an alkanol, is catalytically reduced in a hydrogen atmosphere, either in a batch reactor or in a continuous type of reactor, such as a plug flow reactor. Reduction temperatures and pressures are generally held to between about 80° C. and about 300° C. at pressures of about near ambient pressure to about 500 atms. as can be understood by one skilled in the art. A number of hydrogenation catalysts are useful for this process including palladium on carbon, supported nickel, and supported cobalt materials. Supports are generally metal oxides such as alumina, silica-alumina, and silica. In particular, nickel and palladium catalysts have been found to give conversions to the reduced product of 100 percent and selectivities of over 98 percent. Reaction times depend upon temperature, pressure and catalyst used in the reactor, but in general run between about 0.5 hrs. and about 5 hrs. Beneficially, the reaction mixture is agitated to insure good contact between hydrogen and the substrate as might be expected for this heterogeneously catalysed hydrogenation reaction.
The feed for the ammonolysis-alkylation reaction is a succinic derivative such as the anhydride, acid or diester or the reduction product of maleic anhydride, succinic anhydride. The diester is a dialkyl ester of succinic acid where the alkyl group is a C 1 to C 4 alkyl group, preferably the methyl, propyl, isopropyl or butyl group. Additionally, ammonia and a C 1 to C 4 alkanol are also used in the process, the latter not being necessary in the event a diester is used which forms the corresponding C 1 to C 4 alkanol in situ during the reaction. C 1 to C 4 alkanols useful in this process include methanol, ethanol, propanol, isopropanol, and butanol. Preferred is the use of methanol, ethanol and propanol and, most preferred, is the use of methanol.
The reaction of the substrate, ammonia and the C 1 to C 4 alkanol is carried out under a pressure of about ambient pressure to about 600 atms., more preferably, about 50 atms. to about 400 atms. The reaction temperature is suitably between about 80° C. and about 400° C., more preferably, between about 100° C. and about 350° C. Reaction times depend to some extent upon the pressure and the temperature employed but generally are in the range of about 0.5 hrs. to about 8 hrs., more preferably about 1 hr. to about 4 hrs. It has been found that longer reaction times are required for N-butyl compounds than are required for N-ethyl compounds. N-methyl derivatives appear to form most rapidly under equivalent reaction conditions. The reaction is conveniently carried out batchwise with stirring although a continuous process in a tubular or plug flow reactor is possible. The substrate can conveniently be added as a solution in the alcohol or a nonreactive solvent, preferably excess of the alcohol is used. This ammonolysis-alkylation reaction can be carried out thermally or with the addition of a catalyst if required.
In the slower reactions, those where the N-alkyl group is larger, for example, where a C 2 to C 4 alkanol is used, use of a catalyst is beneficial. For example, a trace of iodine, bromine, an alkyl bromide or iodide, or an alkali metal bromide or iodide can usefully increase the speed of the ammonolysis-alkylation reaction. Transition metal catalysts can also be used.
In general, the reaction of the substrate, ammonia and alkanol can be effected with good conversion and selectivity. For example, N-methylsuccinimide can be formed from succinic anhydride with over 90 percent selectivity and 100 percent conversion.
In general, the reactants, substrate, ammonia, and alkanol, are used in about stoichiometric proportions. Too little ammonia or alkanol results in incomplete conversion, and too much ammonia is wasteful and produces undesirable by-products.
The N-alkyl products are generally easily separated from the reaction mixture because of the high conversions and selectivities. Where product separations are required they are carried out generally by distillation or crystalliztion.
Reduction of the N-alkylsuccinimide is accomplished catalytically with hydrogen, either continuously or batchwise. A variety of types of reactors can be used. The N-alkylsuccinimide is added to the reactor neat or dissolved in excess of the alkanol as a solvent. Catalysts useful for this heterogeneously catalyzed reaction are, generally, nickel supported on a metal oxide and other catalyst types such as copper chromite and cobalt supported on a metal oxide and other similar catalysts. In general, temperature and pressure ranges are those expecte by one skilled in the art for a reaction of this kind. A reduction temperature between about 100° C. and about 500° C., more preferably between about 150° C. and about 300° C., and a reduction pressure of between about 10 atms. and about 600 atms., more preferably, between about 20 atms. and about 400 atms. are used, as can be understood by one skilled in the art. Advantageously, the reaction mixture is agitated by stirring or otherwise mixed in order to improve contact between the reactants. Conversions can be as high as 100 percent with selectivities of 80 to 90 percent. Reaction times of course vary with the reduction temperature, pressure and catalyst used, as may be expected by one skilled in the art, but in general lie between about 1 hr. and about 12 hrs., more preferably, between about 1 hr. and about 6 hrs.
Reduction of the organic substrate together with the ammonolysis-alkylation reaction can be accomplished catalytically by adding hydrogen and a reduction catalyst to the reaction mix. By reduction is meant reduction of a carbonyl group. Catalysts useful for the reduction reaction are, generally, nickel supported on a metal oxide, copper chromite, cobalt supported on a metal oxide, and other similar catalysts. In general, temperature and pressure ranges are those expected for a reaction of this kind and are consistent with those required for ammonolysis-alkylation. A reduction temperature between about 100° C. and about 500° C., more preferably between about 150° C. and about 300° C., and a reduction pressure of between about 10 atms. and about 600 atms., more preferably between about 20 atms. and about 400 atms. can be used, as can be understood by one skilled in the art. Advantageously, the reaction mixture is agitated by stirring, or otherwise mixing, in order to improve contact between the reactants. Reaction times of course vary with the reaction temperature and pressure used, as may be expected by one skilled in the art, but in general lie between about 1 hr. and about 12 hrs., more preferably between about 1 hr. and about 4 hrs.
The following Examples will serve to illustrate certain specific embodiments of the herein disclosed invention. These Examples should not, however, be construed as limiting the scope of the novel invention as there are many variations which may be made thereon without departing from the spirit of the disclosed invention, as those of skill in the art will recognize.
EXAMPLES
General
All reactions were carried out in a stirred 300 cc SS autoclave. Conversions and selectivities were calculated using chromatographic analysis and are expressed in mole percent.
EXAMPLE 1
A 90 g amount of maleic anhydride (MAN) and 9 g of Harshaw Ni-5124T (65% Ni) catalyst were placed in the autoclave and 250 psi of hydrogen was pressured into the reactor after the temperature had been brought to 140° C. The reactor was stirred at 1500 RPM for 2 hrs. after which the reactor was depressurized and the contents removed, cooled and analyzed. MAN conversion was 99% with a 95% selectivity to succinic anhydride (SAN).
A 67 g amount of SAN, 62 g of methanol, and 2.53 g of ammonia were heated 5 hrs. in the autoclave at 300° C. while stirring at 900 RPM. After cooling the product was removed and the SAN was found to be 100% converted at a selectivity to N-methylsuccinimide (NMS) of 90%.
A 90 g amount of NMS was placed in the autoclave together with 9 g of Harshaw Ni 1404T catalyst, and 1600 psig of hydrogen was pressured into the reactor after the temperature had been brought to 230° C. The reactor was stirred for 2 hrs. after which the reactor was depressurized and the contents removed, cooled and analyzed. Analysis showed a 60% NMS conversion with an 89% selectivity to N-methylpyrrolidone (NMP).
The latter reduction was repeated a second time using 9 g of Harshaw Ni-5125T catalyst and a reduction time of 10 hrs. Conversion improved to 86% but the selectivity of 85% found was slightly lower than with the other catalyst.
EXAMPLE 2
A 49.2 g portion of MAN and 12.5 g of palladium on carbon was sealed in the autoclave which was then purged with argon. A 42.3 g amount of ammonium hydroxide and 24 g of methanol were added and 700 psig hydrogen was pressured in. The reactor was heated to 145° C. and held for 1.5 hrs. and then the temperature raised to 270° C. for 10.5 hrs. After cooling and removing the product, it was found that 100% of the MAN was converted and that selectivity to NMS was 80% and selectivity to NMP was 15%.
EXAMPLE 3
A 73 g portion of dimethylsuccinate (DMS), 36.6 g of ammonium hydroxide and 12 g of 5% palladium on carbon were sealed in the autoclave which was first purged with argon and then pressured with 900 psig hydrogen. The autoclave was heated to 260° C. and stirred for 16 hrs. After cooling and removal of the product, analysis gave 100% DMS conversion with a 70% NMS selectivity and a 20% NMP selectivity.
EXAMPLE 4
A 65 g portion of SAN, 41 g of methanol, 12.5 g of ammonia, 12 g of reduction catalyst were sealed in the autoclave, the reactor purged with argon, and 700 psig of hydrogen pressured in. The reactor was heated to 290° C. for 21 hours with stirring. The contents of the reactor were cooled, removed and analyzed. A 100 percent SAN conversion was found with a selectivity to NMS of 60% and a selectivity to NMP of 30%. | An improved process for making N-alkylpyrrolidones from a maleic derivative or a succinic derivative which involves catalytically reducing the maleic derivative with hydrogen to succinic anhydride, if the maleic derivative is the starting point, converting succinic anhydride to a N-alkylsuccinimide by ammonolysis-alkylation with a C 1 and C 4 alkanol and ammonia, and catalytically reducing the resulting N-alkylsuccinimide to the N-alkylpyrrolidone. | 2 |
This invention relates to fixturing to support a gas turbine component blank, and more specifically, to clamping the gas turbine component blank in the fixture and shaping the root of the gas turbine component blank.
BACKGROUND OF THE INVENTION
In the most commonly practiced approach, turbine blades for gas turbine engines are cast to approximately the final shape. Then portions of the turbine blade, such as the root and the shroud, if any, are shaped to the final desired form by a technique such as grinding. The turbine blade is thereafter processed by depositing protective coatings or by other procedures.
The finished turbine blades are assembled into a turbine disk or wheel, with a “dovetail” form on the root of each turbine blade engaging a respective conformably shaped slot on the turbine disk. The turbine disk is in turn supported on a shaft in the gas turbine engine. The turbine blades must have precisely established positions and angular orientations in the turbine disk. Any mispositioning and misorientation may lead to aerodynamic inefficiency and the introduction of unacceptable vibrations in the turbine disk and the turbine blade as the turbine disk turns during service.
Because it is the root of each turbine blade that engages the slot on the turbine disk, the root must be shaped very precisely. Two techniques have been widely used to hold the turbine blade in an exact location and orientation for the shaping of the root. In one, the airfoil of the turbine blade is cast into a matrix of a metal with a low melting point, which is used to hold the turbine blade with its root precursor positioned for grinding or other shaping. This approach, while operable, requires that the low-melting-point metal be cleaned from the surface of the airfoil after the shaping of the root is completed. Even traces of the metal remaining after careful cleaning of the surface of the airfoil may adversely affect the subsequent application of the coatings. Mechanical fixtures or jigs have been developed to hold the turbine blade. These fixtures avoid the use of the low-melting-point metal, but have not been fully satisfactory because they misposition the root precursor or because they do not hold the turbine blades sufficiently repeatably and securely so that each root is shaped the same.
There is a need for an improved approach to the shaping of the roots of turbine blades and other gas turbine components. The present invention fulfills this need, and further provides related advantages.
SUMMARY OF THE INVENTION
The present invention provides a fixture for holding a gas turbine component blank, such as a turbine blade, a compressor blade, or some types of vanes, in a specific fixed position for the shaping of the gas turbine component blank, and a method for performing the shaping. The approach does not use a molten metal whose complete removal is difficult. The fixture holds the gas turbine component blank using features of the gas turbine component blank whose positions are precisely defined. This approach allows each gas turbine component blank to be processed precisely, quickly, securely, reproducibly, without contamination, and with minimal dependence upon operator skill.
A fixture is provided for clamping a gas turbine component blank that is to be shaped into a corresponding gas turbine component. The gas turbine component blank comprises an airfoil having a direction of elongation, and a platform extending transversely to the airfoil and having a top side adjacent to the airfoil and a bottom side oppositely disposed from the top side. The gas turbine blank includes a root precursor at the first end of the airfoil and extending away from the airfoil, wherein the root precursor has a pair of oppositely disposed parallel ends, and a pair of sides which are to be shaped into a dovetail form. There is a rotating shroud located at a second end of the airfoil and extending transversely to the airfoil.
The fixture is used in conjunction with this gas turbine component blank. The fixture comprises a base lying in a base plane and having a datum locator. The datum locator includes an x-axis datum locator upon which the gas turbine component blank is supported so that the direction of elongation of the airfoil is generally parallel to the base plane. The x-axis datum locator prevents movement of the gas turbine component blank perpendicular to the base plane. A y-axis datum locator comprises a first y-axis stop and a second y-axis stop, wherein the first y-axis stop is contacted by a first one of the ends of the root precursor and the second y-axis stop is contacted by the rotating shroud. A z-axis datum locator is contacted by the gas turbine component blank and prevents movement of the gas turbine component blank parallel to the direction of elongation of the airfoil. The fixture further includes a clamp movable between an unclamped position in which the gas turbine component blank may be inserted onto the x-axis datum locator of the base, and a clamped position wherein the clamp simultaneously forces the first end of the root precursor against the first y-axis stop, the rotating shroud against the second y-axis stop, and the gas turbine component blank against the z-axis datum locator.
The clamp preferably comprises a compound mechanical movement that simultaneously forces the gas turbine component blank against the y-axis datum locator and the z-axis datum locator when the clamp is moved from the unclamped position to the clamped position. Most preferably, the clamp comprises a first link pivotably connected to the base and contacting to the root precursor and to the platform when the clamp is in the clamped position, so as to force the first end of the root precursor against the first y-axis stop and to force the platform against the z-axis datum locator, and a second link pivotably connected to the base and contacting to the rotating shroud when the clamp is in the clamped position, so as to force the rotating shroud against the second y-axis stop, the first link having a sliding and pivoting interconnection to the second link. The first link desirably includes a z-positioning spring contacting the bottom side of the platform when the clamp is in the clamped position to force the top side of the platform against the z-axis datum locator. The sliding and pivoting interconnection is preferably a mechanical knuckle. An hydraulic actuator is operable to move the clamp between the unclamped position and the clamped position.
Stated alternatively, a fixture is provided for clamping a gas turbine component blank having an airfoil, a root precursor at a first end of the airfoil, and a rotating shroud at a second end of the airfoil. The fixture comprises a base lying in a base plane and having a datum locator. The datum locator includes an x-axis datum locator upon which the gas turbine component blank is supported to prevent movement of the gas turbine component blank perpendicular to the base plane. A y-axis datum locator comprises a first y-axis stop and a second y-axis stop, with the y-axis datum locator preventing movement of the gas turbine component blank in a first direction lying in the base plane. A z-axis datum locator prevents movement of the gas turbine component blank in a second direction orthogonal to the first direction and lying in the base plane. A clamp is movable between an unclamped position in which the gas turbine component blank may be inserted onto the x-axis datum locator of the base, and a clamped position wherein the clamp simultaneously forces the root precursor against the first y-axis stop, the rotating shroud against the second y-axis stop, and the gas turbine component blank against the z-axis stop. Various modifications and preferred forms as discussed above may be used with this embodiment.
A method for shaping a gas turbine component blank comprises the steps of providing the gas turbine component blank and fixture as discussed, thereafter placing the gas turbine component blank into the fixture with the clamp in the unclamped position, thereafter operating the clamp to move the clamp to the clamped position, and thereafter shaping the gas turbine component blank. The step of shaping preferably includes the step of shaping the sides of the root precursor into the dovetail form, most preferably by grinding.
After the gas turbine component blank is cast and cleaned, the root precursor must be shaped on both its lateral sides, termed the pressure surfaces, and on its end remote from the airfoil, termed the tang. The present fixture may be used to hold the gas turbine component blank for the shaping of the pressure surfaces, while is performed first, and another fixture is used to hold the gas turbine component blank for the shaping of the tang and the final shaping of the end of the root precursor. The present approach provides a convenient fixturing approach which avoids the use of molten metal and also ensures that the gas turbine component blank is properly and securely positioned for shaping of the root precursor, particularly the pressure surfaces of the root precursor.
Other features and advantages of the present invention will be apparent from the following more detailed description of the preferred embodiment, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention. The scope of the invention is not, however, limited to this preferred embodiment.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block flow diagram of an approach for practicing the invention;
FIG. 2 is an elevational view of a turbine blade;
FIG. 3 is a top perspective view of a fixture in which the turbine blade is held for grinding, but without the turbine blade present;
FIG. 4 is a top view of the clamp;
FIG. 5 is a top view of the turbine blade mounted in the fixture, with the clamp arms in the unclamped position;
FIG. 6 is a top view of the turbine blade mounted in the fixture, as in FIG. 5 , but with the clamp arms in the clamped position; and
FIG. 7 is a detail of FIG. 6 , showing the z-positioning spring.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 depicts a method for processing a gas turbine component blank. The gas turbine component blank is provided, numeral 20 . Referring to FIG. 2 , a preferred form of the gas turbine component blank 40 is a turbine blade blank 42 that is processed into a turbine blade. The articles are referred to as “blanks” because they are furnished in a cast and cleaned form that must be given a final shaping, usually by grinding, to achieve the final required shape, and are thereafter final processed. Other gas turbine components such as compressor blades and vanes may, in appropriate cases, be processed according to the approach of FIG. 1 as well.
The turbine blade blank 42 is described in relation to an orthogonal reference system including an x-axis 44 , a y-axis 46 , and a z-axis 48 . The turbine blade blank 42 includes an elongated airfoil 50 extending generally parallel to the z-axis 48 and having an airfoil face 52 . A platform 54 extends transversely to the z-axis 48 at a first end 56 of the airfoil 50 . The platform 54 has a top side 58 adjacent to the airfoil 50 and a bottom side 60 oppositely disposed from the top side 56 . A root precursor 62 is at the first end 56 of the airfoil 50 and extends away from the airfoil 50 along the z-axis 48 . The root precursor 62 has a pair of oppositely disposed parallel ends 64 lying perpendicular to the y-axis 46 , a pair of sides 66 (only one of which is visible in FIG. 2 ) which are to be shaped into a dovetail form, and a tang 68 at an end of the turbine blade blank 42 remote from the airfoil 50 . A rotating shroud 70 is at a second end 72 of the airfoil 50 , remote from the first end 56 . The rotating shroud 70 generally extends transversely to the z-axis 48 and along the y-axis 46 . The rotating shroud 70 is fixed in relation to the airfoil 50 , and is cast integrally with the airfoil 50 . The shroud is termed a “rotating shroud” not because it rotates relative to the airfoil 50 , but because it rotates with the remainder of the turbine blade about the shaft of the gas turbine engine. The rotating shroud is contrasted to a stationary shroud that is found in the gas turbine engine but is not a part of the turbine blade.
A fixture 80 is provided to clamp and hold the gas turbine component blank 40 during subsequent processing, numeral 22 . A preferred form of the fixture 80 is illustrated in FIGS. 3-7 , with and without the gas turbine component blank 40 present. The fixture 80 includes a base 82 that lies generally in a base plane containing the y-axis 46 and the z-axis 48 . The remainder of the fixture 80 is affixed to and supported on the base 82 . The base 82 has an x-axis datum locator 84 , a y-axis datum locator 86 including a first y-axis stop 88 and a second y-axis stop 90 , and a z-axis datum locator 92 . As used herein, a “datum locator” is a feature of the base 82 that serves as a positioning and fixed locating stop and against which the gas turbine component blank 40 is pushed and held fixed by the clamping structure to be discussed subsequently. The datum locators 84 , 86 , and 92 are preferably precisely located supports, surfaces, or shoulders machined into the base 82 . Hard inserts may be affixed to the surfaces of the datum locators that are contacted by the gas turbine component blank 40 to avoid excessive wear of the datum locators. The x-axis datum locator 84 includes several, and typically at least three, x-axis stops 94 that are positioned to receive the gas turbine component blank 40 thereon with one side of the airfoil face 52 in a general facing relationship to the base 82
The fixture 80 further includes a clamp 96 ( FIG. 4 ) movable between an unclamped position ( FIG. 5 ) in which the gas turbine component blank 40 may be inserted onto the x-axis datum locator 84 of the base 82 , and a clamped position ( FIG. 6 ) wherein the clamp simultaneously forces a first end 98 of the root precursor 62 against the first y-axis stop 88 , a first end 99 of the rotating shroud 70 against the second y-axis stop 90 , and some part of the gas turbine component blank 40 , preferably the top side 58 of the platform 54 , against the z-axis datum locator 92 .
To accomplish this simultaneous clamping of the gas turbine component blank 40 against the y-axis datum locator 86 and the z-axis datum locator 92 , the clamp 96 preferably includes a compound mechanical movement 100 , most easily seen in FIG. 4 , that simultaneously forces the gas turbine component blank against the y-axis datum locator 86 and the z-axis datum locator 92 when the clamp 96 is moved from the unclamped position of FIG. 5 to the clamped position of FIG. 6. A preferred form of the compound mechanical movement 100 comprises an asymmetric Y-shaped yoke 102 that is connected to the base 82 .
A first link 104 is pivotably connected to one arm of the yoke 102 at a first pivot point 106 , which is pivotably connected to the base 82 . A contact region 108 of the first link 104 contacts to a second end 110 of the root precursor 62 when the clamp is in the clamped position, so as to force the first end 98 of the root precursor 62 against the first y-axis stop 88 with a hard metal-to-metal contact. The first link 104 further includes a z-positioning spring 112 , preferably in the form of a leaf spring integral with the first link 104 , contacting the bottom side 60 of the platform 54 when the clamp 96 is in the clamped position to force the top side 58 of the platform 54 against the z-axis datum locator 92 . This contacting is shown in detail in FIG. 7 .
A second link 114 is pivotably connected to the other arm of the yoke 102 at a second pivot point 116 , which is pivotably connected to the base 82 . A contact region 118 of the second link 114 contacts to a second end 119 of the rotating shroud 70 , which is oppositely disposed to the first end 99 , when the clamp 96 is in the clamped position of FIG. 5 , so as to force the first end 99 of the rotating shroud 70 against the second y-axis stop 90 . The contact region 118 preferably comprises a spring in the form of a leaf spring. The first link 104 has a sliding and pivoting interconnection 120 to the second link 114 . The sliding and pivoting interconnection 120 preferably comprises a mechanical knuckle 122 .
An hydraulic actuator 124 is operable to move the clamp 96 between the unclamped position of FIG. 5 and the clamped position of FIG. 6 . The hydraulic actuator 124 , which preferably is a liquid-driven actuator to generate a large clamping force but may be a gas-driven pneumatic actuator, desirably controllably generates a force between the base 82 and in this case one side of the yoke 102 , on the one hand, and the first link 104 to cause the first link 104 to pivot about the first pivot point 106 , on the other hand. The second link 114 , through the movement of the interconnection 120 , responsively pivots about the second pivot point 116 . Thus, movement of the single hydraulic actuator 124 generates all of the clamping movements and forces required to clamp the gas turbine component blank 40 in the fixture 80 .
To use the fixture 80 , the hydraulic actuator 124 is retracted so that the first link 104 pivots (counterclockwise in FIG. 4 ) and the second link 114 pivots (clockwise in FIG. 4 ) to the unclamped, open position of FIG. 5 . The gas turbine component blank 40 is placed into the fixture 80 so that the gas turbine component blank 40 rests upon and is supported by the x-axis datum locator 84 , numeral 24 . The hydraulic actuator 124 is then operated and extended so that the first link 104 pivots (clockwise in FIG. 4 ) and the second link 114 pivots (counterclockwise in FIG. 4 ) to the clamped position of FIG. 6 . As the links 104 and 114 pivot to the clamped position, three clamping actions occur. First, the z-positioning spring 112 contacts the bottom side 60 of the platform 54 and forces the gas turbine component blank 40 upwardly so that the top side 58 of the platform 54 is resiliently clamped against the z-axis datum locator 92 . Second, the contact region 118 of the second link 114 contacts the second end 119 of the rotating shroud 70 and forces the rotating shroud 70 along the y-axis 46 (in the negative y direction) so that the first end 99 of the rotating shroud 70 is resiliently clamped against the second y-axis stop 90 . A resilient clamping of the gas turbine component blank 40 against the z-axis datum locator 92 and the second y-axis stop 90 is sufficient because relatively small forces are applied through these locations during subsequent shaping of the gas turbine component blank 40 . Third, the contact region 108 contacts the second end 110 of the root precursor 62 and forces the first end 98 of the root precursor 62 hard (non resiliently) against the first y-axis stop 88 . The root precursor 62 is thus clamped held tightly and securely, with hard metal-to-metal contacts, between the first y-axis stop 88 and the contact region 108 of the first link 104 . This hard, metal-to-metal clamping of the root precursor 62 along the y-axis 46 resists the shaping (grinding) forces produced during the subsequent shaping operation.
Once the gas turbine component blank 40 is clamped into the fixture 80 , the gas turbine component blank 40 is shaped, numeral 28 of FIG. 1 . The shaping using the fixture 80 is preferably the shaping of the sides 66 of the root precursor 62 to define the dovetail form required to affix the final root, and thence the completed turbine blade, to the turbine disk in the gas turbine engine. The shaping 28 is accomplished by any operable approach, but preferably grinding using a creep feed grinder and grinding technique is used. The grinding direction is generally parallel to the y-axis 46 , which is the reason that the secure metal-to-metal clamping of the root between the first y-axis stop 88 and the contact region 108 is required. The creep feed grinder takes relatively large bites of material with each pass, typically on the order of 0.20 inches per pass, and the grinding tool moves rapidly with respect to the root precursor 62 , typically on the order of 45 inches per minute. The forces transmitted to the root precursor 62 and thence to the gas turbine component blank 40 , and the vibrations potentially introduced into the gas turbine component blank 40 , by the creep feed grinder are therefore relatively large. The root precursor 62 must therefore be clamped very securely by the fixture 80 against movement of the root precursor 62 in the y-direction 46 , and the present fixture 80 provides that secure support of the gas turbine component blank 40 . During grinding, a liquid coolant/lubricant is forced around the area of the root precursor 62 being ground. The fixture 80 serves to channel and direct the flow of the coolant/lubricant to the exact location where the grinding tool is contacting the metal of the root precursor 62 , improving the cooling and lubrication of the root precursor 62 .
After the shaping 28 is complete, the hydraulic actuator 24 is retracted to move the clamp 96 to the unclamped position, and the gas turbine component blank 40 is removed from the fixture 80 , numeral 30 . The gas turbine component blank 40 is thereafter further processed, numeral 32 , for any of several reasons and by any of several approaches. There may be further shaping of the root precursor 62 , as for example to shape the tang 68 . There may be coating of the airfoil 50 with protective coatings. Other further processing may be used as desired.
The present approach of FIG. 1 has been practiced using prototype fixturing 80 and found to be fully operable. The clamping of the root precursor 62 in the fixture 80 was found to be more secure and rigid than when the metal encapsulation approach is used, allowing faster grinding rates.
Although a particular embodiment of the invention has been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims. | A gas turbine component blank is shaped by clamping the gas turbine component blank into a fixture that accurately positions the gas turbine component blank in three dimensions. The positioning is accomplished against stops accurately machined into a base of the fixture, by first supporting the gas turbine component blank on one set of stops that prevents movement in the direction perpendicular to a plane of the base, and then operating a movable clamp to force the gas turbine component blank against other sets of stops that limit the movement of the gas turbine component blank in directions lying in the base plane. The clamp has a compound movement that simultaneously forces the gas turbine component blank against stops that prevent movement in orthogonal directions lying in the base plane. The gas turbine component blank is thereafter shaped, preferably by grinding the sides of the root precursor of the gas turbine component blank. | 1 |
This is a continuation-in-part of application Ser. No. 826,097 filed Aug. 19, 1977, now abandoned which is a continuation of application Ser. No. 664,606 filed Mar. 8, 1976 now Pat. No. 4,053,550, which is a continuation-in-part of application Ser. No. 506,386 filed Sept. 16, 1974 now abandoned.
This invention generally relates to vulcanization of flexible elastomeric or plastomeric materials or of structures comprising same. In particular, although not exclusively, the invention is directed to a method and apparatus for vulcanizing long lengths of flexible unsheathed and unvulcanized hose formed, for example, by extrusion or by helical winding or both and wherein an unvulcanized hose product is fed into a vulcanization chamber in a continuous manner while simultaneously, completely vulcanized hose product is being drawn out of the chamber at substantially the same rate.
It will be understood from the following discussion that the expression "vulcanized" means subjecting an unvulcanized product to an elevated temperature and pressure for a period of time such as to cause the development of a cross-linked integral structure.
It will further be understood that the expression "continuous" means feeding into the vulcanization atmosphere a length of material on a continuous basis such that while one portion of unvulcanized material is being fed into the chamber, another portion is within the chamber being vulcanized while still another portion of completely vulcanized material is being drawn out of the chamber.
The invention first consists in a method of vulcanizing long lengths of flexible elastomeric or plastomeric hose material in a continuous manner comprising driving an assembled unvulcanized hose product through a vulcanizing atmosphere within a closed chamber without stretching or changing any pre-established structural orientation of reinforcement within the hose, the hose product being driven in the form of a helix having convolutions which in part contact a driving member and in part contact an idler member both of which are mounted within the chamber.
The invention secondly consists in apparatus for continuously vulcanizing long lenghts of elastomeric or plastomeric hose product comprising
a horizontal pressure chamber;
means providing a vulcanization atmosphere within the chamber;
pressure retaining inlet means for feeding the hose product into the chamber at a minimum of tension such that any internal orientation of the hose structure is maintained upon entry into the chamber;
pressure retaining outlet means in spaced horizontal relationship to the inlet means for drawing out completely vulcanized hose product from the chamber in synchronism with the amount of hose product entering the chamber at the inlet means;
a driving member and at least one idler member horizontally mounted in parallel spaced-apart positions for rotation within the chamber, the relationship of the driving and idler members being such that portions of helically wound convolutions of hose product contact both members while other portions are free of any contact with either member and completely exposed to the vulcanization atmosphere, the hose product following a helical path about the driving and idler members from the inlet to the outlet;
a resilient diaphragm disposed on the surface of at least one of said members in a manner to support hose product thereon in spaced positions along the length thereof while the other of said members has a contoured surface of substantially concave positions throughout its length such as to accept helical convolutions of hose product from the other of said members and reposition said product on that member in a next successive and advanced helical position, and
means connected to said driving member to rotate said member and thus effect movement of the material through the chamber from the inlet to the outlet means.
Various objects and advantages of the invention will become apparent and better appreciated and understood from a consideration of the following description when taken in conjunction with the accompanying drawings in the several figures of which like-reference numerals indicate like-elements and in which:
FIG. 1 is a plan view, partially in section and partially diagrammatic of the apparatus comprising the invention;
FIG. 2 is a side elevational view, partially in section, of the vulcanization chamber comprising the invention;
FIG. 3 is an end view, partially in section, as taken on line 3--3 of FIG. 2;
FIG. 4 is a partial plan view taken on line 4--4 of FIG. 3;
FIG. 5 is a sectional elevational view taken on line 5--5 of FIG. 4.
DESCRIPTION OF THE INVENTION
Referring to the drawings, FIG. 1 illustrates the apparatus of the invention which generally comprises a vulcanization chamber 10, an inlet feed and tension control mechanism 12 for feeding unvulcanized material 14a into the chamber 10, an outlet control mechanism 16 for drawing out completely vulcanized material 14b, means 18 for providing a vulcanization atmosphere within the chamber 10, a primary rotating member 20 journalled for rotation within the chamber and over which the material 14 moves in a helical path from the inlet to the outlet, an idler member 30 and drive means 34 for effecting rotation of the primary member 20.
In the operation of the above described apparatus, the material to be vulcanized will be a flexible elastomeric or plastomeric hose product 14a which may be fed from a previously assembled store thereof as for example from a supply drum, or it may be a feed of unvulcanized hose product directly from apparatus for the manufacture thereof as for example from the head of an extruder or other final stage manufacturing apparatus. In either circumstance, the hose product is unsheathed, i.e., it is not encased in a lead sheath or covering as is the usual practice in the vulcanization of this type product. The hose may, however, be internally supported by a flexible rubber mandrel or it may be internally pressurized by an air or liquid pressure to resist collapse when in the influence of the vulcanization atmosphere within the chamber 10. Alternatively, the hose product's internal structure may be designed such as to resist collapse and in this case no internal support may be required upon being subjected to the vulcanization atmosphere. The unvulcanized hose product 14a is fed into the inlet feed mechanism 12 which handles it in a manner such that a minimum of tension exists or is imparted to the product as it is fed into the vulcanization chamber 10. That the hose product is fed into the chamber at a minimum of tension is important and it is well known and understood for example in the manufacture of a wire or textile reinforced hose product that the reinforcing be maintained at an approximate angle of 55° with respect to the hose axis upon being vulcanized so as to maintain dimensional stability and to obtain the optimum strength characteristics of the product. Thus, the inlet feed and tension control mechanism 12 operates to feed the unvulcanized hose product into the vulcanization chamber at a minimum of tension as determined by the type of structural reinforcing within the product. This may be accomplished by one of many known methods within the knowledge and skill of persons working in the hose manufacturing art, as for example by tension control pulleys, a caterpillar drive mechanism or the like. The exact mechanism that might be used to accomplish the inlet tension control is beyond the scope of the present invention and therefore will not be specifically described but suffice it to say that the unvulcanized hose product is fed into the chamber and laid onto the primary rotating member 20 within the chamber at a minimum of tension such that the orientation of the structural reinforcing within the product is maintained at the pre-established optimum for the product being vulcanized.
The unvulcanized hose product 14a is fed into the chamber through a pressure seal 12a at the inlet and laid onto the primary rotating member 20 in the form of a helix, the convolutions of the helix moving through the length of the chamber to the outlet that also includes a pressure seal 16a and outlet control mechanism 16. The outlet mechanism 16 may be similar to the inlet feed control mechanism 12 and its purpose is to draw out the completely vulcanized hose product 14b such that the amount of hose product being drawn out of the chamber is in synchronism with the amount of material being fed into the chamber. This synchronism is to maintain a continuous flow of material into and out of the chamber without any build-up within the chamber due to either an increased inlet feed rate or a slower outlet draw rate. Again, the manner of accomplishing synchronism and tension control at the inlet and outlet is considered a matter of preference and within the skill and knowledge of the hose manufacturing art and therefore will not be specifically described.
Referring now to FIGS. 2 through 5, the specific contents of the vulcanization chamber are shown in detail and generally comprise a primary rotating member 20 and an idler member 30. The primary rotating member 20 comprises a drum horizontally journalled within the chamber 10 which may be one of various known constructions within the art but for the purpose of this description is shown as a prefabrication of cast aluminum circular segments 20c that are fastened or welded together to form a right circular cylinder of the desired diameter. The drum has end plates 20a and 20b that support shaft segments 24a and 24b that are bearing mounted at 26 and 28 respectively. One shaft segment 24a is connected to a drive shaft 32 that effects rotation of the drum by reason of a drive motor 34.
An idler rotating member 30 is also mounted in the chamber in a substantially parallel relationship to the drum 20. The mounting of the idler is made to a carriage support generally indicated by reference numeral 40 that also mounts the drum 20 thereon by reason of upright members 42, 44. The idler member may be a series of freely rotating individual pulleys or alternatively a single cylindrical drum having a contoured surface for receiving the hose product therearound or it may be a series of guide members that operate in the manner hereinafter to be described. As clearly evident in FIGS. 2 and 3 the convolutions of the helixed hose product pass around the primary rotating drum 20 as well as the idler 30 and the helical movement of the hose product is essentially effected by the positioning of the idler member. In other words, the idler functions to pick up the hose convolutions from the drum 20 and indexes each to a new advanced and successive position on the surface of the drum. An additional horizontally mounted set of rollers or alternatively a simple bar 50 may be mounted relative to the drum and the idler to keep each of the convolutions of hose in its proper position between the time it leaves the idler and the time it is laid on the drum 20.
FIGS. 4 and 5 illustrate the particular configuration of the drum 20 such as to maintain orientation of the hose convolutions thereon. The segments that comprise the cylindrical drum structure are characterized by annular, radially extending ribs 20d that carry and support a substantially flexible elastomeric diaphragm 52 thereon. The rib spacing is chosen so that the diaphragm which may have a thickness within the range of 0.03 inches to 0.25 inches (0.076 mm to 6.35 mm) flexes inwardly toward the drum and substantially craddles the hose product 14 in a concave groove formed in the diaphragm by reason of the weight of the hose product. The diaphragm 52 covers the total surface of the drum and is fastened at each end 20a, 20b by stainless steel band clamps 54 that are tightened circumferentially about the diaphragm and drum. Compensation of the differences in expansion of the stainless steel band 54 and the aluminum drum 20 is accomplished by an additional rubber ply 56 positioned beneath the stainless band. The compound of the ply 56 is chosen such as to allow for the difference in expansion and contraction of the two metals while maintaining sufficient band pressure on the diaphragm to keep it from loosening on the drum. Of course other means may be used to fasten down the diaphragm and the invention is not considered limited to any particular type method or fastening means.
Because the diaphragm 52 is suspended across the ribs 20d, a space 58 is created between it and the drum 20. In this circumstance, a plurality of breather holes 60 are provided in the diaphragm to equalize any differences in pressure that may occur between the volume of the space 58 and the atmosphere of the chamber 10. The holes also serve to drain accumulated condensate in the space 58 that would tend to cause sagging of the diaphragm at the bottom position of the drum. The holes 60 may be punched or molded into the diaphragm at regular or random intervals across its surface and the number of such holes is a matter of choice depending on their size, the spacing of the ribs 20d, and the amount of condensate that may accumulate.
In addition and because of the large drum diameter (approximately 10 feet) and its long length (approximately 20 feet), the flexible diaphragm may be held to the drum by additional stainless steel bands mounted in the same manner as the end bands 54 or alternatively, the diaphragm may be held in place by coil springs 62 that are bound circumferentially about the diaphragm and positioned between two ribs 20d as shown in FIG. 5. It will be appreciated that the spring 62, while effectively holding the diaphragm to the drum, also provides a tensioning device as the diaphragm tends to expand and/or contract due to the chamber atmosphere while the hose product is being transported helically on its surface. Tensioning of the diaphragm also compensates for any variation in the diaphragm diameter and in any possible variations in the length of the hose convolutions in adjacent positions on the drum. It is, of course, contemplated that other tensioning means may be provided at one or both ends of the drum which impart a longitudinal tension to the diaphragm and it is also contemplated that the amount of such tension may be adjusted by a particular choice of springs 62 or any other device or means capable of being affixed to the drum 20.
The apparatus within the chamber 10 are mounted on a tracked platform or carriage 46 that may be withdrawn from the chamber by reason of an end door opening 10a and a disconnect assembly 48 on the drive shaft 24a of the drum. Thus, upon removal from the chamber, the drum may be serviced and upon an initial start up of the vulcanization process, a lead line may be threaded about the drum in the helical path to be followed by the hose product. This is necessary inasmuch as the system is obviously not self-threading or self-feeding at start up.
While certain representative embodiments and details have been shown for the purpose of illustrating the invention, it will be apparent to those skilled in this art that various changes and modifications may be made therein without departing from the spirit or scope of the invention. | Method and apparatus for continuously vulcanizing unsheathed and unvulcanized elastomeric or plastomeric material by passing the material through an enclosure, within which it is subjected to vulcanizing conditions, in the form of a helix, the helix convolutions in part contacting a drive member and idler member and in part being freely suspended. A resilient elastomeric diaphragm is disposed on the surface of one of the said members. | 1 |
EMULSION PROCESS FOR POLYMER PARTICLES
This is a continuation-in-part of patent application Ser. No. 837,390 filed Sept. 28, 1977, now abandoned, and the same is incorporated herein by reference.
BACKGROUND OF THE INVENTION
The present invention pertains to a process for synthesizing large size uniform emulsion polymer particles made from polymeric seeds onto which is added monomer polymerized in a second stage. The resultant large polymer particles may be homogeneous but normally will be of a heterogeneous nature and are particularly useful for providing improved physical properties in coatings, plastics, and adhesives. Core/shell particles can be effectively produced. Heterogeneous core/shell polymer particles wherein the core can be a rigid polymer having a high Tg relative to a resilient elastomeric shell having a lower Tg can be conveniently produced in large size without experiencing emulsion instability.
Although seeded emulsion polymerization processes and particles have been suggested in the past, in such processes said particle surface coverage by the surfactants must be less than 100% surface coverage or less than critical-micelle-concentration (CMC). However, too little surfactant or considerably less than 100% surface coverage of the polymer seed particles introduces stability problems and produces considerable excessive coagulation. For example, U.S. Pat. No. 3,657,172 and U.S. Pat. No. 3,426,101 specifically provide for high surface tension in second stage processing as well as maintaining the concentration of surfactant well below the critical-micelle-concentration (CMC) to avoid 100% surfactant coverage of the seed. More specifically, U.S. Pat. No. 3,397,165 proposes that the core surfactant surface coverage be maintained below 70% theoretical surface coverage in the second monomer addition.
It now has been found that the second stage monomer addition can be carefully controlled wherein substantially all of the second stage monomer addition effectively adds to the seed particles whereby the seed particle can be substantially increased due to utilizing excess surfactant beyond CMC or at least about 105% seed surface coverage. The second stage monomer addition can be accurately controlled in accordance with the process of this invention by using a certain balance of non-ionic surfactant and anionic surfactant at a combined surfactant coverage of between about 105% and 1000% of the polymer seed surface to provide a grown composite particle where the second stage monomer has polymerized and completely associated itself with the first stage seed particle. The process further provides a method of controlling the surfactant in the second stage monomer polymerization wherein the balanced combination of surfactants provides at least about 105% seed surface coverage and preferably between 105% and 500% seed surface coverage.
Accordingly, a primary object of this invention is to provide a process for producing stabilized large size emulsion particles formed by polymerizing all of the second stage monomer addition onto the polymer seed in the presence of a controlled combination of non-ionic and anionic surfactants. A further object is to provide a process for controlling the level of second generation new particles and provide a stabilized interdispersion of heterogeneous composite particles or core/shell particles in combination with a predetermined level of new generation particles achieved by controlling the levels of total surfactant above 105% seed surface coverage as well as controlling the balance ratio of non-ionic to anionic surfactants.
These and other advantages will become more apparent by referring to the drawings and detailed description of this invention.
SUMMARY OF THE INVENTION
The process of this invention comprises the steps of first providing substantially monodispersed polymeric seed particles in a polymerization process followed by a second stage monomer polymerization after adjustment of the seed surface coverage to a level between 105% and 1000% seed surface coverage using a controlled balance ratio of non-ionic surfactant to anionic surfactants.
IN THE DRAWINGS
FIG. 1 is a graph of percent by weight of non-ionic surfactant "N" vs. percent seed surfactant surface coverage "S" indicating by contour lines the weight fraction "y" of second stage monomer added to the first generation polymer seed;
FIG. 2 is a graph derived from FIG. 1 wherein the composite particle comprised by weight 35% seed polymer and 65% second stage polymer at a (D p /D i ) 2 =2.01 wherein the contour lines indicate the weight fraction "y" of second stage monomer added to the first stage seed; and
FIG. 3 is also a graph derived from FIG. 1 wherein the composite particle is comprised by weight 50% seed polymer and 50% second stage polymer at (D p /D i ) 2 =1.59 wherein the contour lines have the same meaning. D p is the projected diameter of the composite particle and D i is the diameter of initial seed polymer particle.
DETAILED DESCRIPTION OF THE INVENTION
The process of this invention pertains to a method of controlling the second stage polymer development wherein second stage monomer selectively associates with first stage polymer seed particles to form composite polymer particles and/or forms distinct new second stage particles to provide an in-situ latex blend of composite particles and second stage polymer particles.
The controlled second stage process of this invention is particularly effective if the first stage polymer seed particles are substantially uniform size polymer particles. The uniform seed particles are thereafter utilized in a second stage seeded polymerization process wherein second stage monomer either adds completely onto pre-existing latex polymer seed particles or simultaneously produces second generation new particles to form an in-situ blend. The suppressing or promotion of second generation new polymer particles is achieved in accordance with this invention by controlling the second stage total surfactant coverage above about 105% polymer seed surface coverage and by particularly controlling the weight fraction of non-ionic surfactant at greater than 30% of the total surfactant comprising non-ionic and anionic surfactants. Preferably, the non-ionic surfactant comprises between 30% and 98% of the total second stage surfactant which in turn provides between about 105% and 1000% theoretical polymer seed surface coverage. The second stage seeded polymerization process includes preformed seed latex, water medium, minor additives like chain transfer agents and buffers, second stage monomers, initiators, electrolyte, and surfactant as hereinafter described.
Referring first to the first stage of the process of this invention, substantially uniform polymer particle seeds are synthesized by an emulsion polymerization process to produce an aqueous dispersion of monodisperse polymer particles having substantially a uniform particle size or diameter. An advantage of uniform first stage seeds is that the amount of second stage monomer addition to the seed is uniform among all the individual seed particles to produce uniform composite latex particles. The size can be determined by disc centrifuge or electron microscopy. Since both the seed and the composite particles are uniform in size, simple size comparisons provide accurate information on second stage addition or seed growth. This allows for quality control and the change to make necessary alterations to achieve desired uniform mass production of the latex. In the particular use of core/shell composite particles, uniform seeds and, consequently, uniform core/shell particles provide uniform spacing of the cores within coatings, adhesives, and plastics where the latex polymer is the main polymeric ingredient. This provides better flexibility-hardness balance.
Substantially uniform particle seeds can be produced in accordance with U.S. Pat. No. 3,423,351 by an emulsion process of polymerizing monomers having carbon-to-carbon unsaturation. Suitable seed polymers include for example, homopolymers or copolymers of any of the monomers having at least one ethylenically unsaturated group which are well known to those skilled in the art to undergo addition polymerization under the conditions of emulsion polymerization in aqueous medium. Among these as illustrative examples are 1,3-butadiene, 2-methyl-1,3-butadiene, 2,3-dimethyl-1,3-butadiene, allylbenzene, diacetone acrylamide, vinylnaphthalene, chlorostyrene, 4-vinyl benzyl alcohol, vinyl benzoate, vinyl propionate, vinyl caproate, vinyl chloride, vinyl oleate, dimethyl maleate, maleic anhydride, dimethyl fumarate, vinyl sulfonic acid, vinyl sulfonamide, and methyl vinyl sulfonate. Particularly preferred monomers include for example, N-vinyl pyrolidone, vinyl pyridine, styrene, alpha-methyl styrene, tertiary butyl styrene, vinyl toluene, divinyl benzene, vinyl acetate, vinyl versatate, alkyl acrylates and methacrylates such as ethyl acrylate, butyl acrylate, 1,6-hexanediol diacrylate, ethylthioethyl methacrylate, methyl acrylate, isobornyl acrylate, 2-hydroxyethyl acrylate, 2-phenoxyethyl acrylate, glycidyl acrylate, 2-ethylhexyl acrylate, neopentyl glycol diacrylate, 2-ethoxyethyl acrylate, t-butylaminoethyl methacrylate, 2-methoxyethyl acrylate, methyl methacrylate, glycidyl methacrylate, benzyl methacrylate, ethyl methacrylate, acrylic acid, methacrylic acid, N-methyl methacrylamide, acrylonitrile, methacrylonitrile, acrylamide, N-(isobutoxymethyl)acrylamide, and the like. The preformed polymer seed particles are substantially monodispersed or uniform in size and this can be measured by a Joyce Loebl Disc Centrifuge using a procedure described by Provder and Holsworth in American Chemical Society Coatings and Plastics Preprints, 36,150, (1976). The diameter of the polymer particle seeds can also be determined by electron-microscopy techniques in accordance with the procedure described by S. H. Maron in the "Journal of Applied Physics", Vol. 23, page 900, August, 1952. In determining the uniformity of particle diameter or monodispersity, the average weight diameter (D w ) is divided by the average number diameter (D n ) wherein the D w /D n theoretically approaches 1.0 and preferably is within the range of 1.0 to 1.04 in accordance with this invention. D w is the polymer particle weight average diameter and D n is the polymer particle number average diameter. The values D w and D n can be determined in accordance with the procedures described by Loranger, et al, in the "Official Digest", Vol. 31, pages 482-520, particularly pages 491-2 (1959). Preferably, the seed weight average particle diameter D w is between about 500 A and about 8000 A as well as the monodispersity D w /D n ratio being broadly between 1.0 and 1.1 and preferably between about 1.0 and 1.04.
In accordance with this invention, a seed growth of finite amount can be achieved by providing a certain combination of non-ionic and anionic surfactants in the second stage monomer addition to form an enlarged latex particle from polymers and copolymers of ethylenically unsaturated vinyl monomers such as 1,3-butadiene, 2-methyl-1,3-butadiene, 2,3-dimethyl-1,3-butadiene, allylbenzene, diacetone acrylamide, vinylnapthalene, chlorostyrene, 4-vinyl benzyl alcohol, vinyl benzoate, vinyl propionate, vinyl caproate, vinyl chloride, vinyl oleate, dimethyl maleate, maleic anhydride, dimethyl fumarate, vinyl sulfonic acid, vinyl sulfonamide, methyl vinyl sulfonate, and preferably N-vinyl pyrolidone, vinyl pyridine, styrene, alpha-methyl styrene, tertiary butyl styrene, vinyl toluene, divinyl benzene, vinyl acetate, vinyl versatate, alkyl acrylates and methacrylates such as ethyl acrylate, butyl acrylate, 1,6-hexanediol diacrylate, ethylthioethyl methacrylate, methyl acrylate, isobornyl acrylate, 2-hydroxyethyl acrylate, 2-phenoxyethyl acrylate, glycidyl acrylate, 2-ethylhexyl acrylate, neopentyl glycol diacrylate, 2-ethoxyethyl acrylate, t-butylaminoethyl methacrylate, 2-methoxyethyl acrylate, methyl methacrylate, glycidyl methacrylate, benzyl methacrylate, ethyl methacrylate, acrylic acid, methacrylic acid, N-methyl methacrylamide, acrylonitrile, methalcrylonitrile, acrylamide, N-(isobutoxymethyl)acrylamide, and the like. The second stage addition of ethylenically unsaturated monomers can be added to the aqueous solution containing the preformed monodisperse polymer seeds along with surfactants and polymerizing catalysts or initiators and other minor ingredients. The amount of second stage monomer is broadly between 5 and 95 and preferably between 20 and 80 weight percent of the total of the seed polymer and the second stage monomer. Initiators can include for example, typical free radical and redox types such as hydrogen peroxide, t-butyl hydroperoxide, di-t-butyl peroxide, benzoyl peroxide, benzoyl hydroperoxide, 2,4-dichlorobenzoyl peroxide, t-butyl peracetate, azobisisobutyonitrile, ammonium persulfate, sodium persulfate, potassium persulfate, sodium perphosphate, potassium perphosphate, isopropyl peroxycarbonate, and redox initiators such as sodium persulfate-sodium formaldehyde sulfoxylate, cumene hydroperoxide-sodium metabisulfite, potassium persulfate-sodium bisulfite, cumene hydroperoxide-iron(II) sulfate, etc. The polymerization initiators are usually added in amounts between about 0.1 to 2 weight percent based on the monomer addition.
The process of this invention is dependent considerably upon the balance of non-ionic and anionic surfactant which controls the amount of available monomer which will add to the preformed polymer particle seeds. The relationship of surfactants depends upon (N) the weight percent of non-ionic surfactant as well as the (S) the seed latex surface coverage. The surface coverage (S) of the polymer seed particle is at least about 105% and advantageously between 105% and 1000%, and preferably between 105% and 500%. The surface coverage is dependent upon a certain finite concentration of surfactant referred to as critical-micelle-concentration (CMC) wherein the CMC point is theoretically 100% surfactant surface coverage of the seed particle whereupon additional soap produces very little change in surface tension and theoretically no further soap can be absorbed or accommodated as a monolayer by the latex polymer surface.
Broadly, the fraction of new particles formed in the second stage polymerization is inverse to the fraction of non-ionic surfactant and the relative amount of second stage monomer, but is proportioned to the seed surfactant surface coverage. This behavior is depicted in FIG. 1: Entirely composite particles (like core/shell) can be produced by controlled use of non-ionic and anionic surfactant mixtures. The higher above 105% seed surfactant surface coverage used, the greater the percentage of the surfactant must be non-ionic. Further, the greater the amount of next stage monomer which is used relative to the seed particles, the greater the total seed surface coverage (S) can be used at any given percentage non-ionic. This is expressed by the multiplying factor (D p /D i ) 2 where D p is the diameter of the final composite particle (assuming for calculation purposes no new particle formation) and D i is the diameter of the seed particles. All new particles can be produced to obtain an in-situ blend of seed and new particles by decreasing the percentage of non-ionic surfactant and increasing the seed surface coverage. This is aided by decreasing the relative amount of monomer being used in the next stage relative to the seed particles. Partial addition of the polymerizing monomer to form enlarged composite particles and partially new particles is obtained by selecting percentages of the seed surface coverage and the percentage non-ionic surfactant to be between the extreme values of these variables used to obtain entirely composite particles or entirely new particles. In the case of the continuous incremented addition of the second stage monomer to seed particles, the instantaneous (D p /D i ) 2 is virtually equal to one, and it is assumed for calculation purposes that all the monomer already fed has been fully polymerized and added to the seed.
The exact contours for any particle figure like FIG. 1 are obtained by mapping out the N,S area for a particular type of seed and type of second stage composition by making experimental latexes at well spaced N,S and (D p /D i ) 2 values. FIG. 1 gives the experimentally determined contours for a polystyrene seed and second stage styrene-acrylic or all acrylic copolymer. FIG. 1 is also experimentally accurate for the other compositions illustrated in the examples.
Suitable anionic surfactants include for example, salts of fatty acids such as sodium and potassium salts of stearic, palmetic, oleic, lauric, and tall oil acids, salts of sulfated fatty alcohols, salts of phosphoric acid esters of polyethylated long chain alcohols and phenols, etc. Preferred anionic surfactants include for example, alkylbenzene sulfonate salts such as sodium dodecylbenzene sulfonate and salts of hexyl, octyl, and higher alkyl diesters of 2-sulfosuccinic acid, etc. Suitable non-ionic surfactants include polyoxyethylene glycols reacted to a lyophilic compound to produce a hydrophile-lyophile balance (HLB) greater than 2 and preferably between about 10 and 15 as set forth in U.S. Pat. No. 3,423,351. Suitable non-ionic surfactants include for example, ethylene oxide condensation products reacted with t-octylphenol or nonylphenol and known as "Triton" surfactants, polymerized oxyethylene (IgepalCA), ethylene oxide reacted with organic acid (Emulfor), or organic acid reacted with polyoxyamylene ether of stearic or oleic acid esters (Tweens).
In accordance with this invention, the uniform size polymer particle seeds were dispersed in an aqueous medium containing certain surfactants and the second stage monomer added and reacted in a temperature range of about 50°-80° C. for about 4-16 hours. The water amount was fixed at between about 30%-70% level and preferably at the 50% level based on particle seed and second stage monomer whereby the resulting composite latex would be approximately a 50% by weight latex. The second stage polymerization process of providing growth of the seed to composite particles will become more apparent by referring to the following illustrative examples.
EXAMPLE 1
The following were reacted in accordance with the procedure set forth in U.S. Pat. No. 3,423,351 to produce a 5-gallon reactor batch of uniform size polymer seed particles.
______________________________________9.0 grams anionic sodium dodecyl benzene sulfonate (Siponate DS-10; 95.4% active)233.8 grams non-ionic arylalkyl ether alcohol (Triton X-100; 98.4% active)778.0 grams 0.1 Molar sodium hydroxide405.1 grams of 3% by weight water solution of K.sub.2 S.sub.2 O.sub.88617.7 grams of de-ionized water6757.9 grams Styrene16,801.5 grams total charge______________________________________
About half of the water was charged to the reactor followed by the Siponate DS-10, the Triton X-100, and the NaOH. The mixture was then stirred and sparged with N 2 for about 45 minutes. The 3% K 2 S 2 O 8 water was then added with the remainder of the water. The styrene was thereafter added to the mixture in the reactor while agitating to emulsify the solution mixture followed by upheating the mixture to about 65° C. The reaction mixture was maintained at about 65° C. for about 16 hours while agitating for complete conversion of the styrene into polystyrene seed particles. The seed particles had an average particle diameter of about 2464 A as measured by disc centrifuge; a density of about 1.057; and the latex had a non-volatile (NVM) of 41%, and the seed particles were monodisperse. The seed surface coverage was 100%. Percent surface coverage is calculated from direct tritration of the latex by a mixture of the two surfactants to obtain the CMC. This procedure is basically described by Maron in "Journal of Colloid Science," 9, 89-103 (1954), and Abbey, Erickson, and Seidewand in "Journal of Colloid and Interface Science," 66,1, 203-204 (1978).
EXAMPLE 2
The following materials were added to a 5-liter reactor and agitated while sparging with N 2 .
1096.2 grams de-ionized water
2.16 grams Siponate DS-10 (95.4% active)
38.88 grams Triton X-100
1.89 grams K 2 S 2 O 8
After the foregoing was dissolved in water, the following was emulsified therein.
1350.0 grams of the seed latex of Example 1
706.05 grams n-butyl acrylate
282.15 grams Styrene
20.25 grams methacrylic acid
The mixture was then upheated to 65° C. and maintained at 65° C. for about 12 hours with agitation to completely polymerize the second stage monomer.
The addition of the seed latex from Example 1 to the solution of the surfactants caused the seed surface coverage to jump from 100% to 314% and the N became 95%. The addition of the shown monomers gave the calculated (D p /D i ) 2 a value of 2.01. The D p is calculated from the relative weights and densities of the seed and the second stage monomers. The density of the second stage monomer used is that after polymerization. The combination of N, S, and (D p /D i ) 2 used was selected to induce all the second stage monomer to add to the seed to give entirely composite particles as required by FIG. 2. Examination of the latex of Example 2 by disc centrifuge according to the method described by Seidewand and Erickson in "Polymer Engineering and Science", 18, 15, 1182-1185 (1978), showed that all the second stage monomer added to seed to produce composite particles. The latex was clean and stable.
EXAMPLE 3
The following materials were added to a 12-ounce bottle reactor:
85.12 grams de-ionized water
0.52 grams Siponate DS-10 (95.4% active)
5.72 grams Triton X-100
0.14 grams K 2 S 2 O 8
After the foregoing was dissolved in water, the following was emulsified therein:
100.00 grams of the seed latex of Example 1
52.30 grams of n-butyl acrylate
20.90 grams styrene
1.50 grams methacrylic acid
The mixture was then upheated to 65° C. and maintained at 65° C. with rolling for 16 hours to completely polymerize the second stage monomer. The addition of the seed latex from Example 1 to the solution of surfactants caused the seed surface coverage to jump to 543% with an N equal to 93%. The calculated (D p /D i ) 2 value for the latex of Example 3 was 2.01. The N, S, and (D p /D i ) 2 selected was to obtain a latex exhibiting partial seed growth and partial new particle generation. From disc centrifuge analysis it was determined that the weight fraction, y, of second stage monomer that added to seed was 0.3 as predicted by FIG. 2. The latex was clean and stable.
EXAMPLE 4
The following materials were added to a 5-liter reactor:
741.2 grams de-ionized water
6.08 grams Siponate DS-10 (95.4% active)
0.27 grams Triton X-100
1.89 grams K 2 S 2 O 8
After the foregoing was dissolved in water, the following was emulsified therein:
1971.0 grams of the seed latex of Example 1
673.6 grams n-butyl acrylate
102.6 grams styrene
16.2 grams methacrylic acid
The mixture was then upheated to 65° C. and maintained at 65° C. while agitating for 14 hours to completely polymerize the second stage monomer. The surfactant surface coverage on the seed was 144%, N was 74%, and (D p /D i ) 2 was 1.59. These values were selected to produce entirely composite particles, i.e. y=1 as predicted by FIG. 3. The latex was clean and stable and the disc centrifuge analysis showed y=1.
EXAMPLE 5
The following materials were added to a 12-ounce bottle reactor:
65.60 grams de-ionized water
0.82 grams Siponate DS-10 (95.4% active)
9.04 grams Triton X-100
0.14 grams K 2 S 2 O 8
After the foregoing was dissolved in water, the following was emulsified therein.
146.00 grams of the seed of Example 1
49.90 grams of n-butyl acrylate
7.60 grams styrene
1.20 grams methacrylic acid
The mixture was then upheated to 65° C. and maintained at 65° C. while rolling for 16 hours to completely polymerize the second stage monomer. S was 577%, N was 93%, and (D p /D i ) 2 was 1.59. These values were selected to produce only new particles. See FIG. 3. The latex was clean and stable. Disc centrifuge analysis showed that y=0, meaning that only new particles formed as predicted.
EXAMPLE 6
The following components were reacted to form a uniform sized seed latex:
______________________________________12.9 grams Siponate DS-10 (91.1% active)256.9 grams Triton X-100552.2 grams 0.1 molar sodium hydroxide7.6 grams potassium persulfate (K.sub.2 S.sub.2 O.sub.8)8377.1 grams de-ionized water7507.5 grams styrene16,714.2 grams total charge______________________________________
All of the ingredients except the K 2 S 2 O 8 and enough water to make a 5% aqueous solution of the K 2 S 2 O 8 were added to a 5-gallon reactor, stirred and sparged with N 2 gas for 10 minutes. The sparge was removed and the mixture heated to 65° C. The 5% solution of K 2 S 2 O 8 was added. The reaction mixture was maintained at 65°-67° C. After the reaction exotherm subsided (approximately 90-95% conversion) the batch was heated to 90°-92° C. and held for 3 hours assuring high conversion. The seed particles had a density of 1.056 gram per cm 3 . The NVM was 45.6%. The average particle diameter measured by disc centrifuge was 2461 A and D w /D n was 1.02. This seed particle was used in second stage processing according to Examples 2-5 and illustrated in Table I of Example 10.
EXAMPLE 7
The following components were reacted to give a uniform sized seed latex:
______________________________________1.70 grams Siponate DS-10 (94.1% active)34.00 grams Triton X-1002266.61 grams de-ionized water1.70 grams NaHCO.sub.311.90 grams acrylamide3.40 grams K.sub.2 S.sub.2 O.sub.81700.00 grams styrene3.40 grams dodecyl mercaptan (DDM)4022.71 grams total charge______________________________________
The first 5 ingredients were charged to a 5-liter reactor, stirred and heated to 72° C. while purging with N 2 gas, then a N 2 atmosphere was maintained. The K 2 S 2 O 8 was added, followed by 27% of the styrene-DDM mixture. The reaction mixture was maintained at 72°-73° C. for approximately 1 & 1/2 hours. The addition of the remainder of styrene-DDM mixture was started and continued for 4 hours while maintaining the reaction mixture at 72°-75° C. The batch was then held for approximately 2 hours at 80°-85° C. to complete the polymerization. The NVM was 42.5%; particle density was 1.058; the average particle diameter was 2430 A. The seed particles were used in second stage processing as further illustrated in Table I in Example 10.
EXAMPLE 8
The following components were reacted according to the procedure of Example 7 to give a uniform sized seed latex.
______________________________________0.68 grams Siponate DS-10 (94.1% active)34.00 grams Triton X-1002266.61 grams de-ionized water1.70 grams NaHCO.sub.311.90 grams acrylamide3.40 grams K.sub.2 S.sub.2 O.sub.81700.00 grams styrene3.40 grams dodecyl mercaptan11.33 grams 3% aqueous K.sub.2 S.sub.2 O.sub.84033.02 grams total charge______________________________________
The final addition of K 2 S 2 O 8 solution was followed by an additional 2-hour hold to further assure complete conversion. The NVM was 43.5%; particle density was 1.058; the average particle diameter was 3890 A. The seed particles were utilized in second stage processing as illustrated in Table I in Example 10.
EXAMPLE 9
The following components were loaded into a 12-ounce bottle reactor and polymerized for 17 hours at 65° C.
______________________________________142.61 grams de-ionized water0.39 grams K.sub.2 S.sub.2 O.sub.851.05 grams methyl methacrylate25.95 grams ethyl acrylate220.00 grams total charge______________________________________
After filtering, the NVM was 33.7%; dark field microscopy at 400X revealed the sample was monodisperse. Particle density was 1.184; JLDC average particle diameter was 7454 A; D w /D n was 1.03. These seed particles were utilized in second stage processing as illustrated in Table I.
EXAMPLE 10
The following examples, 10 through 20, were prepared similarly to Examples 2-5 by utilizing the polymer seed particles prepared in Examples 6-9.
TABLE I (a)______________________________________Example 10 11 12______________________________________Seed of example 6 6 6Ingredients:Seed 367.18 419.63 419.71K.sub.2 S.sub.2 O.sub.8 -- 0.43 0.43Azobisisobutyronitrile 0.38 -- --De-ionized Water 129.18 191.29 192.97Siponate DS-10 (91.1% active) 0.68 0.80 1.29Triton X-100 1.80 2.14 0.83Methyl Methacrylate 100.00 -- 34.00Methacrylic Acid -- -- 2.00n-Butyl Acrylate -- 50.0 64.00Vinyl Acetate -- 50.0 --Reactor Size 12 oz. 12 oz. 12 oz.Polymerization Temp. (°C.) 65 65 65(D.sub.p /D.sub.i).sup.2 1.30 1.31 1.32S 140 142 140N 89 88 83Predicted y* 1 1 1Experimental y 1 0.9 1______________________________________ *Predicted from Figure 1 using the applicable (D.sub.p /D.sub.i).sup.2 value.
TABLE I (b)______________________________________Example 13 14 15 16______________________________________Seed of example 6 6 7 7Ingredients:Seed 367.18 121.67 74.19 74.19K.sub.2 S.sub.2 O.sub.8 0.38 0.23 0.21 0.21Dodecyl Mercaptan -- -- 0.20 0.20De-ionized Water 129.18 160.58 95.34 96.69Siponate DS-10 (94.1% active) -- -- 1.06 0.23Siponate DS-10 (91.1% active) 0.68 0.30 -- --Triton X-100 1.80 1.84 3.12 2.60Methyl Methacrylate 100.00 100.00 23.00 23.00Methacrylic Acid -- -- 2.00 2.00n-Butyl Acrylate -- -- 75.00 75.00Reactor Size 12 oz. 12 oz. 12 oz. 12 oz.Polymerization Temp. (°C.) 65 65 65 65(D.sub.p /D.sub.i).sup.2 1.30 1.91 2.55 2.55S 140 230 451 308N 89 93 78 93Predicted y 1 1 0.7 1Experimental y 1 1 0.8 1______________________________________
TABLE I (c)______________________________________Example 17 18 19 20______________________________________Seed of example 6 8 9 9Ingredients:Seed 121.67 170.70 98.91 98.91K.sub.2 S.sub.2 O.sub.8 0.38 0.28 0.27 0.27Dodecyl Mercaptan -- 0.20 -- --De-ionized Water 118.58 86.88 133.49 133.64Siponate DS-10 (94.1% active) -- 0.36 0.07 0.27Siponate DS-10 (91.1% active) .35 -- -- --Triton X-100 2.16 0.78 0.61 0.26Styrene 25.00 -- -- --Methyl Methacrylate -- 33.00 66.30 66.30Methacrylic Acid 2.00 2.00 -- --Ethyl Acrylate -- -- 33.70 33.70n-Butyl Acrylate 70.00 65.00 -- --1,6-Hexanediol Diacrylate 3.00 -- -- --Reactor Size 5 liter 5 liter 12 oz. 12 oz.Polymerization Temp. (°C.) 65-85 72-75 65 65(D.sub.p /D.sub.i).sup.2 2.01 1.75 2.52 2.52S 229 165 262 275N 91 86 90 50Predicted y 1 1 1 0.7Experimental y 1 1 1 0.6______________________________________ | An improved two-step process for producing large size emulsion polymer particles includes the steps of providing uniform size polymer particles in the first stage followed by a controlled second stage monomer polymerization which overcomes stability problems in large size composite emulsion polymer particle systems, and is particularly useful in coatings, adhesives, and plastics. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part application of U.S. patent application Ser. No. 14/900,605, filed on Dec. 21, 2015, entitled EQUIPMENT FOR SANITIZING THE AIR CONDITIONING SYSTEM OF VEHICLES BY MEANS OF RADIANT CATALYTIC IONIZATION (Atty. Dkt. No. DBGG-32938), which is a National Stage Entry of International Application Ser. No. PCT/IB2014/001557, filed on Jun. 19, 2014, entitled EQUIPMENT FOR SANITIZING THE AIR CONDITIONING SYSTEM OF VEHICLES BY MEANS OF RADIANT CATALYTIC IONIZATION, which claims priority from Brazil Patent Application No. 1320130154163, filed on Jun. 19, 2013, which is a Certificate of Addition of and claims priority from and/or benefit of Brazil Patent Application No. 1020120011220, filed 17 Jan. 2012, each of which is incorporated herein by reference in their entirety; and this application is also a continuation-in-part of U.S. patent application Ser. No. 14/372,637, filed on Jul. 16, 2014, entitled DEVICE FOR SANITIZING THE AIR-CONDITIONING SYSTEM OF VEHICLES USING RADIANT CATALYTIC IONIZATION (Atty. Docket No. DBGG-32219), which is a National Stage Entry of International Application Ser. No. PCT/BR2013/000020), filed Jan. 17, 2013, which claims priority from Brazil Patent Application No. 1020120011220, filed Jan. 17, 2012, and entitled EQUIPAMENTO PARA HIGIENIZAçÃO DO SISTEMA DE AR CONDICIONADO DE VEÍCULOS POR MEIO DE IONIZAçÃO RADIANTE CATALÍTICA, each of which is incorporated herein by reference in their entirety.
TECHNICAL FIELD
[0002] This invention relates to equipment for sanitizing the air conditioning system of vehicles by means of radiant catalytic ionization, in particular, to sanitizing equipment that uses the radiant catalytic ionization technology, promoting a reaction between UVX light and a noble metal alloy generating a purifying plasma, efficient in sanitizing not only the air conditioning, but also the interior environment of vehicles. Additionally, this application relates to equipment for sanitizing the air conditioning system and interior of vehicles in general through the transformation of the ambient air into a purifying plasma primarily containing hydrogen peroxide and hydroxyl radicals.
[0003] Embodiments may also include sanitizing equipment that have a field of application in the automotive sector, notably in air conditioning and the interior environment of transportation vehicles in general. Additionally, embodiments may also have a field of application in the heating, ventilation and air conditioning (HVAC) systems or equipment for sanitizing the HVAC system and the interior of vehicles in general through the transformation of ambient air into purifying plasma primarily containing hydrogen peroxide and hydroxyl radicals. Moreover , embodiments can also be applied or incorporated into the HVAC system of various transportation vehicles, including but not limited to, land, sea, or air vehicles such as, for example, trains, busses, rail vehicles, boats, submarines, airplanes, trams, or other personal or public transportation vehicles (hereinafter referred to as “vehicles” or “transportation vehicles.”
BACKGROUND
[0004] The existing solutions for sanitizing interiors and air conditioning systems of, for example, automotive vehicles are based on technologies that use various resources, among these the application of chemical products and manual mechanical intervention, vaporization/nebulization system for chemical products, oxi-sanitizing of interiors, which consists of applying ozone, among others.
[0005] Among the conventional practices used to sanitize interiors and air conditioning systems, some drawbacks stand out that deserve mention, for example:
[0006] Application of chemical products and manual mechanical intervention:
This method needs technically skilled labor, which increases the application cost; Mechanical intervention does not reach all possible contaminated spots due to its physical limitations, and takes more time for its execution; Chemical products (those that do not comply with regulatory standards) when applied can cause general discomfort to users due to possible human allergic sensitivity.
[0010] Vaporization/nebulization system for chemical products:
A deficiency of vaporization/nebulization systems is their known limitations for being able to reliably resolve and not just cover up sanitizing and odor problems, which compromises their efficiency and effectiveness; Thus, this system also compromises the final quality of the services rendered.
[0013] Oxi-sanitizing of interiors:
A deficiency of this technique is the risk that the application of ozone in interior environments can in a general way harm the health of users; In improperly measured amounts, ozone concentration in interior environments can cause respiratory discomforts, nausea, and mucous membrane oxidation, among other unwanted reactions or irritations to humans.
[0016] In the face of this situation and the deficiencies inherent in current sanitizing practices, there is a need to develop equipment capable of accomplishing in the internal environment of a vehicle significant, reliable removal of odors human irritants without the use of chemical agents. The focus of this application is to provide a device and method to help resolve the deficiencies of prior sanitizing practices.
[0017] The prior art includes some patent documents that deal with the matter in question. For example, Brazilian Patent No. PI9306305-9, titled “PROCESS AND SYSTEM FOR AIR DISINFECTION IN AIR CONDITIONING DUCTS,” is directed to a process for disinfecting air that consists of aerosol type vaporization of a deodorant that includes a quaternary ammonia compound, more specifically benzyl ammonium chloride, which is nonpoisonous and substantially nonvolatile. The benzyl ammonium chloride is mixed in water which by means of micro vaporizers goes through and is provided via the air flow in a duct.
[0018] The above solution, although appealing in order to disinfect air in air conditioning or HVAC system ducts, has a limitation factor in the matter of aerosol vaporization, which will certainly not go through the whole pipe, making its application ineffective, and also it utilizes ammonia as a disinfectant, which, although not poisonous, may not be tolerated by some organisms including humans, resulting in adverse allergic reactions.
SUMMARY
[0019] Cognizant of the prior existing solutions, including its gaps and limitations, studies and research were performed in order to develop embodiments of equipment for sanitizing the HVAC systems of vehicles by means of radiant catalytic ionization, which in general is sanitizing equipment that uses radiant catalytic ionization technology that promotes a reaction between ultraviolet or UVX light and a noble metal alloy so as to generate a purifying plasma comprised mainly of hydrogen peroxide, which is efficient in sanitizing the HVAC systems as well as the interior of transportation vehicles.
[0020] In short, invention embodiments may have one or more of the following advantages, each of which may improve the efficiency and effectiveness in sanitizing the interior, the air conditioning system, and/or HVAC systems of transportation vehicles. As such embodiments may have attributes that enable:
An embodiment to remove odors of most possible origins; An embodiment to not need skilled labor for its application; An embodiment to be directly applied or installed in the environment in the presence of people, without needing to isolate the site for any period of time; An embodiment to be incorporated into equipment that is easy to handle and operate; An embodiment having an active principle that includes hydrogen peroxide, which is an oxidant present in nature and therefore does not require any manufactured chemical products; An embodiment that during operation emits odorless and neutral smelling characteristics as perceived by a user or vehicle occupant; An embodiment that does not use chemical products, thereby reducing the incidence of possible side effects due to the use of unregulated products, even when applied in inadequate amounts; An embodiment that does not require mechanical intervention for application or removal, because such embodiments may use only air as the dissemination or carrier medium; An embodiment that does not use ozone, which, though also using air as the conducting or carrier medium, can cause health problems, in contrast to the technology utilized in various embodiments.
[0030] In some embodiments of the invention a device is provided that has a first and a second module. The first module comprises a UVX lamp configured to produce UV light. The first module also has a first and a second honeycomb structure of surfaces. Each honeycomb structure is impregnated or coated with a noble metal allow and configured to generate via a radiant catalytic ionization reaction with the UV light, a purifying plasma comprising oxidative sanitizing molecules. The first and the second honeycomb structures are each positioned in locations that are adjacent to the UVX lamp such that the UV light can impinge on a majority of the surfaces making up the honeycomb structures while air flows thereover. The first module may also include a first frame on which the UVX lamp and the first and the second honeycomb structure of surfaces are mounted. Additionally, the first module may include a cover portion the combines or attaches to the first frame to establish an enclosure that enables air to pass through the first and the second honeycomb structure of surfaces when the first module is positioned in a duct of a HVAC system of a transportation vehicle.
[0031] In some embodiments, the second module may be located remotely from the first module. The second module is electrically connected to the first module by one or more electrical connections. The second module comprises control circuitry that includes components to provide power and control functions of the UVX lamp and that connect to the transportation vehicle's control circuitry. The second module may be configured to be positioned within or proximate to a control console of the transportation vehicle while being remote from the first module.
[0032] In some embodiments the first module may also include a fan for pushing or pulling air flow over the surfaces of the first and the second honeycomb structure of surfaces.
[0033] In other embodiments, the first cover portion is integral with the duct of the HVAC system.
[0034] In some embodiments, the UVX lamp comprises a plurality of UVX LEDs.
[0035] In various embodiments, the purifying plasma comprises hydrogen peroxide and hydroxyl radicals. The purifying plasma uses air as a carrier medium.
[0036] In yet other embodiments, the duct of the HVAC system is an output duct that passes HVAC system treated air into a passenger compartment of the transportation vehicle.
[0037] In some embodiments, the first cover portion combines with the first frame to establish an exterior covering about the first module with openings that enable air to pass through the first and the second honeycomb structure of surfaces.
[0038] Additionally in some embodiments, a temperature sensor is positioned in the first module and configured to sense an output temperature of the purifying plasma from the first module, wherein the control circuitry is configured to turn off the UVX lamp if the sensed output temperature is greater than a predetermined temperature when the HVAC system of the transportation vehicle is set to cool the interior air of the transportation vehicle to a user set temperature as a maximum rate.
[0039] Also in some embodiments, an airflow sensor is positioned in the first module to sense a flow of air or plasma through the first module, wherein the control circuitry is configured to turn off the UVX lamp if the sensed output of the air flow sensor indicates that the flow of air or plasma is below a predetermined flow rate.
[0040] In another embodiment of the invention a transportation vehicle is provided that comprises an HVAC system that is integrated into the transportation vehicle. The HVAC system includes an air duct configured to distribute HVAC system conditioned air into the interior of the transportation vehicle, such as an automobile. The transportation vehicle also includes an air sanitizing device integrated into the HVAC system; the air sanitizing device may comprise a first module. The first module of the air sanitizing device comprises a UVX lamp configured to produce UV light. The first module may also include a first and a second air permeable structure, such as a honeycomb, mesh, woven, screen, louvres, slotted or other structure having a plurality of surfaces, wherein each air permeable structure has surfaces is impregnated or coated with a noble metal alloy, such as titanium dioxide, and configured to generate, via a radiant catalytic ionization reaction with the UV light, a purifying plasma comprising oxidative sanitizing molecules; the first and second air permeable structures each are positioned adjacent to the UVX lamp such that the UV light can impinge on a majority of the air permeable structure's surfaces while air flows thereabout and there over. The first module may also include a first frame on which the UVX lamp and the first and second air permeable structures having a plurality of surfaces are mounted. The first frame is configured to be positioned in the air duct such that air is enabled to pass through, and in some embodiments about, the first and second air permeable structure's surfaces. The air sanitizing device also comprises a second module positioned or located in the vehicle, yet remotely from the first module. The second module is connected to the first module by an electrical connection of one or more conductive connections the may carry power or signals between the first and second modules. The second module comprises control circuitry that includes components and circuitry that provide power to the first module and control functions associated with the UVX lamp or other devices or sensors that are part of the first module, such as temp sensors or a fan. The second module is configured to be positioned within or proximate to a control console of the transportation vehicle while being remote from the first module. The second module may connect via a second electrical connection to a vehicle control circuit.
[0041] In some embodiments, the first module further comprises a first cover portion that combines with or removably attaches to the first frame to establish an enclosure that enables passage of air through the first and the second honeycomb structure surfaces. The first cover portion may be integral with the air duct of the HVAC system. In other embodiments the first cover portion my comprise the air duct of the HVAC system to which the frame of the first module is mounted.
[0042] In another embodiment of the invention air sanitizing device is provided. The air sanitizing device is configured to be integrated with an HVAC system. The air sanitizing device comprises a first module and a second module. The first module comprises a UVX lamp configured to produce UV light. The first module also comprises at least a first air permeable structure having a plurality of surfaces, each air permeable structure having at least a portion of its surfaces impregnated or coated with a noble metal alloy, which includes titanium dioxide, and configured to generate, via a radiant catalytic ionization reaction with the UV light, a purifying plasma comprising oxidative sanitizing molecules; the at least first air permeable structure having surfaces each being positioned adjacent to the UVX lamp such that the light can impinge on a majority of the surfaces while air flows there over or thereabout. The first module may also include a first frame on which the UVX lamp and the at least one air permeable structure of surfaces are mounted. The first frame is configured to be positioned in the air duct such that air within the air duct is enabled to pass through and over the surfaces of the air permeable structure and it surfaces. The second module of the air sanitizing device is located remotely from the first module. The second module is connected to the first module by an electrical connection that may carry power or signals between the two modules. The second module comprises control circuitry that includes component circuitry configured to provide power and control functions for the UVX lamp and, in some embodiments, logic and connection circuits for integration with the HVAC system of the transportation vehicle control circuitry. The second module may be configured to be positioned within, proximate to, or remotely from a control console and/or control circuitry of the transportation vehicle while being remote from the first module. The second module may be connected to the vehicle control circuitry by an electrical cable or connections.
BRIEF DESCRIPTION OF THE DRAWINGS
[0043] For a more complete understanding, reference is now made to the following detailed description taken in conjunction with the accompanying illustrative Drawings in which:
[0044] FIG. 1 is a schematic view showing main components of an embodiment of equipment for sanitizing the air conditioning system of transportation vehicles by means of radiant catalytic ionization;
[0045] FIG. 2 is a functional schematic representation of an embodiment of the equipment for sanitizing the air conditioning system of vehicles by means of radiant catalytic ionization;
[0046] FIG. 3 is a perspective view of an embodiment of the equipment for sanitizing the air conditioning system of vehicles by means of radiant catalytic ionization;
[0047] FIG. 4 is an inverted perspective view of an embodiment of the equipment for sanitizing the air conditioning system of vehicles by means of radiant catalytic ionization;
[0048] FIG. 5 is a schematic perspective view of another embodiment of the equipment for sanitizing the air conditioning system of vehicles by means of radiant catalytic ionization;
[0049] FIG. 6 is an exploded schematic perspective view of an embodiment of the equipment for sanitizing the air conditioning system of vehicles by means of radiant catalytic ionization; and
[0050] FIG. 7 is a schematic perspective view of the an embodiment of the equipment for sanitizing the air conditioning system of vehicles by means of radiant catalytic ionization showing a use condition.
DETAILED DESCRIPTION
[0051] Referring now to the drawings, wherein like reference numbers are used herein to designate like elements throughout, the various views and embodiments of the equipment for sanitizing the air conditioning system of vehicles by means of radiant catalytic ionization are illustrated and described. In addition, other possible embodiments are also described. The figures are not necessarily drawn to scale, and in some instances the drawings have been exaggerated and/or simplified in places for illustrative purposes only. One of ordinary skill in the art will appreciate the many possible applications and variations based on the following examples of possible embodiments.
[0052] Referring to FIGS. 1-4 , the equipment for sanitizing the air conditioning system of vehicles by means of radiant catalytic ionization, relates to equipment 10 mounted in a framework 20 that is able to hold a UVX light bulb 30 surrounded at least on two sides by a beehive or honeycomb structure 40 that is impregnated or coated with a metal alloy so that the honey comb structure 40 transforms air/oxygen (A) into a purifying plasma (P) composed of hydroxyl radicals and hydrogen peroxide.
[0053] More particularly, embodiments of the sanitizing equipment 10 comprise a framework 20 with symmetrical and opposing circular cavities or openings where there is intake 50 for accepting surrounding air (A) to be drawn by a fan 60 into the equipment 10 . The intake fan 60 is equipped with a protective grating 70 between the fan 60 and the exterior of the sanitizing equipment. There is an outlet cavity or opening 75 allowing passage of purifying plasma (P), through an insufflation grating 80 , for passage out of the equipment 10 and into the surrounding air (A). Properly speaking, the air (A) inters through the intake 50 and passes by a UVX light bulb 30 located in the intermediate internal part 45 of the framework's interior. In this way, UVX light bulb 30 is surrounded by a beehive or honeycomb structure 40 having surfaces that are impregnated or coated with a noble metal alloy, which predominantly comprises titanium dioxide. In this context, upon switching on the connect-disconnect switch (ON-OFF switch) 90 , the UVX light bulb 30 is lighted and the fan 60 pulls or pushes air through the framework's interior, thus processing and transformation air into an air purifying plasma (P) comprised of hydroxyl radicals and hydrogen peroxide. The air purifying plasma (P) could be applied at two different ventilation or fan speeds as controlled by speed button 100 , as well as having an application time predetermined by a digital timer relay with hour, minutes and seconds activated by operational control 110 . The equipment is supplemented by a number of applications counter 120 and cell or control unit 130 , which comprises circuitry responsible for the operation of the UVX light bulb unit 30 .
[0054] Embodiments of the invention utilize radiant catalytic ionization technology, which, through a reaction between UVX light, a noble metal alloy and air, produces purifying plasma composed mainly of hydrogen peroxide, and may also comprise hydroxyl radicals and various other components. When air passes through a honeycomb structure 40 that has its surfaces impregnated or coated with a noble metal alloy, including titanium dioxide, while a UVX lamp 30 proximate to the honeycomb structure 40 emits UVX light that impinges on surfaces of the honeycomb structure(s) 40 . Thus, generation of the plasma (P) is achieved through radiant catalytic ionization. Furthermore, the purifying plasma uses air as it carrier medium.
[0055] The air (A) is drawn in into the sanitizing equipment 10 through an intake 50 by means of a fan 60 . In some embodiments a protective grating 70 is positioned over the intake area and adjacent to the fan 60 , such that the intake air flows through the protective grating 70 as it enters the interior of the framework 20 . The fan 60 may be activated before, after or simultaneously when the UVX lamp is turned on via the ON-Off switch 90 .
[0056] A cell or control unit 130 contains circuitry that controls the workings of the UVX bulb 30 , the fan 60 , and other electronics that control and track the workings of the sanitizing equipment 10 . In some embodiments, the control unit 130 is detachably attached to the framework 20 with an electrical connection 132 there between. The control circuitry within the control unit is connected via the electrical connection 132 to control the ON-OFF and intensity of the UVX bulb 30 , the speed of the fan 50 in accordance with how a user set up the operational control 110 of the equipment 10 . In various embodiments, the control circuitry of the control unit 130 also monitors one or more sensors 136 mounted within the framework. The one or more sensors may monitor temperature or humidity in order to provide feedback to the control circuitry in order to 1) increase or decrease the UV intensity output of the UVX bulb depending on whether the humidity is above or below a predetermined humidity range, or 2) increase the fan speed if the temperature within the equipment is above a predetermined range in order to cool the UVX bulb.
[0057] In some embodiments the UV light is produced by a plurality of UVX LEDs positioned to emit UV light onto the surfaces of the honeycomb structure(s) 40 . A honeycomb structure is used to maximize the surface area of the noble metal alloy coating that UV light can impinge on inside the limited area of the framework interior proximate to the UVX bulb or LEDs.
[0058] In other embodiments, the ON-OFF switch 90 , speed button 100 , operational control 110 and number of operations counter may be positioned on the detachable control unit 130 so that the control unit 130 can be positioned and used by a user remotely from the location of the framework 20 enclosure part of the device. For example, the framework enclosure portion 20 of the device may be positioned in a location that is out of reach of the user or perhaps within an air duct of a building, bus, train, boat or other HVAC system in a building, temporary structure or transportation vehicle. When out of the reach of a user, control unit may be remotely located or incorporated into a structure or vehicle so that a user can control the workings of the equipment 10 .
[0059] In various embodiments, the application of the plasma can be set to be performed for predetermined periods of time and/or at two different speeds selected with a control button 110 .
[0060] In various embodiments, the portability of the equipment 10 facilitates the maneuverability and positioning thereof directly on the interior of the vehicle where it takes place or in the inlet region where air is conducted or directed into the air conditioning system of the vehicle.
[0061] Using a similar, yet different configuration, other embodiments provide a more compact sanitizing equipment device. Other embodiments may provide a sanitizing device configured into two modules that can be located or positioned remotely from one another while being incorporated into the design of the vehicle. The compacting of the equipment into two modules makes integration onboard automobiles and other means of transportation easily achievable. By virtue of a more compact design, it is possible to perform the installation and of the UVX lamp module by incorporating and/or installing it at a strategic point along or directly in the path traveled by the air used in the HVAC or air-conditioning system of the vehicle.
[0062] The tables below show tests that corroborate the efficacy of an equipment embodiment when employed in a passenger vehicle in terms of the concentration of fungi and bacteria, and the measurement of direct readings for temperature, humidity, volatile organic compounds, carbon monoxide, particulate matter and formaldehydes. The tests were conducted on two vehicles—one with the equipment and one without it.
[0000]
TABLE 1
Fungi Tests
Environmental monitoring and control of possible colonization,
multiplication and dissemination of fungi in the interior ambient air.
I/E ratio
Characterization of
Sample no.
Ambient air
Outside air
Ambient
sampling (sampling
Recommended
(CFU/m 3 )
(CFU/m 3 )
air/air
Genera of fungi
plan)
rates
≦750
0
(limit ≦1.5)
isolated
Golf PXX1444 - with
31484/12
17
1734
0.0
Cladosporium sp.;
treatment
Penicillium sp.;
Rhodotorula sp.;
Phoma
sp.; Alternaria sp.
Fiesta DAI4309 -
31485/12
34
1734
0.0
Cladosporium sp.;
without treatment
Penicillium sp.;
Rhodotorula sp.
[0063] Note 1: The tests above were performed in accordance with the requirements of Resolution—RE no. 09 of MS/ANVISA of 16 Jan. 2003.
[0000]
TABLE 2
Test for Bacteria
Environmental monitoring and control of possible colonization,
multiplication and dissemination of bacteria in the interior ambient air.
Characterization of
Sample no.
Ambient air
Outside air
I/E ratio
sampling (sampling
Recommended
(CFU/m 3 )
(CFU/m 3 )
Ambient air/air
plan)
rates
≦750
0
(limit ≦1.5)
Golf PXX1444 - with
31482/12
315
331
1.0
treatment
Fiesta DAI4309 -
31483/12
772
331
2.3
without treatment
[0000]
TABLE 3
Evaluation of temperature, humidity, volatile organic compounds, carbon monoxide, particulate
matter and formaldehydes.
Carbon
Temperature
Humidity
VOCs
monoxide
Aerosols
Formaldehydes
Site
° C.
(%)
g/m 3
(ppm)
μg/m 3 )
Ppm
Recommended
0
0
500.0
See note 3
50
2 [cropped]
rates
Outside air
29.5
41.9
835.7
3.9
77.3
< [cropped]
Golf PXX1444 -
22.6
52.4
432.8
0.5
6.3
< [cropped]
with
treatment
Fiesta
24.1
52.1
624.7
1.3
62.5
50 [cropped]
DAI4309 -
without
treatment
[0064] Note 2: The tests above were performed in accordance with the requirements of the Green Building Council, IEQ Credit 3.2
[0065] Note 3: According to Green Building Council, IEQ Credit 3.2, the recommended rate must be 9 ppm and not more than 2 ppm greater than the outside concentration.
[0066] Based on the above tables, equipment embodiments employed in a passenger vehicle unexpectedly decreased the amounts of volatile organic compounds, carbon monoxide, and particulate matter by significant amounts while the passenger vehicle was parked, yet running with the windows closed when compared to another similar passenger vehicle without the equipment installed. In particular, equipment embodiments decreased fungi by about 50%; decreased bacteria by about 59%; decreased VOCs by about 30%; decreased carbon monoxide by about 61%; and decreased aerosols by about 89% within the test passenger vehicle as compared to a similar passenger vehicle operating without the aid of an equipment embodiment.
[0067] Referring now to FIGS. 5, 6 and 7 , another embodiment of equipment for sanitizing the air conditioning system of vehicles by means of radiant catalytic ionization 200 is shown. This embodiment of equipment 200 may be a result of decreasing the equipment overall size and separating it into two distinct modules 210 and 220 . The scale of the two modules 210 and 220 is small enough so as to enable installation of the modules directly in or integrated into an air conditioning or HVAC system of transportation vehicles, such as passenger vehicles or other means of transportation including trucks, busses, trains, airplanes, construction or agriculture vehicles, boats, recreation vehicles, or other vehicles.
[0068] More particularly, the equipment 200 of this compact design may be manufactured such that a first module 210 contains the UVX lamp 230 , and a second module 220 that includes a cell or control unit having respective components responsible for the powering and/or controlling the functions of the lamp 230 . The first and second modules 210 , 220 are preferably distinct and can be remotely located from each other so as to enable installation of the first module 210 with the UVX lamp 230 at a strategic point within or along the path traveled by air within a duct 222 used in the air-conditioning or HVAC system of the vehicle 300 . Thus, air moving within a duct 222 also passes by the UVX lamp 230 and through an air permeable structure 250 , shown as a honeycomb structure, and over its surfaces, which are impregnated or coated with a noble metal alloy. In some embodiments, the air moving within the duct 222 passes by the UVX lamp or bulb 230 and through an air permeable structure 250 , which may be a screen, a lattice, a woven mesh, an organization of tubes or honeycomb shapes or other are permeable structure having some all of its surfaces coated or impregnated with a noble metal alloy that predominately includes titanium dioxide. The air permeable structure 250 may be positioned adjacent to and/or about a portion of the UVX lamp 230 . The air coming from the forced ventilation of the vehicle, which passes through the first module 210 , is subjected to a radiant catalytic ionization reaction, generating purifying plasma having a high level of sanitizing power. The purifying plasma can sanitize the air conditioning system air and duct inner surfaces. Additionally, it has been determined that the purifying plasma may also sanitize the air and the inner surfaces of the entire vehicle compartment.
[0069] In some embodiments, the first module 210 comprises a frame 260 with a covering 270 that are combined or attached to each other to form and establish an interior enclosure. Lateral openings 280 are located on opposing sides of the interior enclosure formed by the frame and covering. The lateral openings 280 allow for the passage of air moving within the air duct to go through the first air permeable structure 250 into the interior enclosure past the UVX lamp 230 and out of the interior enclosure via a second air permeable structure 252 and back into the air duct 222 . In some embodiments one or more sensors 256 may be installed within the interior enclosure of the first module 210 . The one or more sensors may sense humidity, temperature, or estimate the airflow movement within the first module.
[0070] In other embodiments, the first module 210 has a UVX lamp that when turned ON produces UV light. On one longitudinal side of the UVX lamp is the first air permeable structure 250 . On another longitudinal side of the UVX lamp is a second air permeable structure 252 . Both the first and second air permeable structures 250 , 252 are impregnated or coated with a noble metal alloy that is predominantly titanium dioxide. The noble metal alloy is configured to generate by way of a radiant catalytic ionization reaction with UV light, when emitted from the UVX lamp 230 , and the air proximate thereto, a purifying plasma that includes oxidative sanitizing molecules. Such oxidative sanitizing molecules include hydroxyl radicals and hydrogen peroxide. In other embodiments, a single air penetrable structure 250 is mounted to the frame 260 such that it is about a portion of or adjacent to the UVX lamp 230 and such that air moving through the duct penetrates through the air permeable structure 250 .
[0071] A frame portion 260 and cover portion 270 may establish an exterior covering about the first module 210 and contain the UVX lamp 230 and the first and second air permeable structures 250 , 252 . The UVX lamp and first and second air permeable structures 250 , 252 may be mounted on the frame portion 260 within an interior enclosure established by the frame and, in some embodiments, the cover portion 270 . Cut-away portions or lateral openings 280 enable lateral passage of air into and out of the interior of the first module 210 by way of passing through the first and second air permeable structure 250 , 252 when the first module is positioned within an air duct or integrated into an air duct structure of an HVAC system of a transportation vehicle.
[0072] Additionally, embodiments may include a second module 220 located remotely from the first module and within the transportation vehicle. The second module 220 may be electrically connected to the first module 210 . The second module 220 includes a cell or control circuitry 240 that provides power and controls the functions of the UVX lamp 230 within the first module 210 . The control circuitry 240 may also be configured to be connected 242 to other circuitry within the transportation vehicle 300 . The cell or control circuitry 240 may be attached to a frame portion 290 of the second module 220 . A cover portion 294 may combine and attach to the frame portion 290 to establish an exterior covering of the second module such that the control circuitry is enclosed within the covering.
[0073] As shown in FIG. 7 , the second module 220 may be positioned remotely from the first module 210 . An electrical connection is provided between the first and second modules to enable the second module to provide power and to share control signals to and from the first module in order to control and monitor the workings of the UVX bulb and other sensors 256 , such as humidity, temperature (air, bulb or honeycomb structure) and the air flow rate through the first module. The control circuitry 240 may comprise a ballast or other voltage and current controlling circuitry so as to enable the control circuitry 240 to provide appropriate voltage and current to the UVX lamp or bulb 230 . The control circuitry 240 may use the sensed output from the sensors for a variety of purposes. For example, it has been found that the amount of humidity in the HVAC air affects the rate of radiant catalytic ionization reaction that occurs to create the purifying plasma. As such, if the humidity sensor indicates that the humidity is below a predetermined low humidity indication, the control circuitry may turn the UVX bulb OFF. Conversely, if the humidity sensor indicates that the humidity is above a predetermined high humidity indication, the control circuitry may lower the power to or intensity of UV light emitted by the of the UVX bulb in order to save energy, increase the life expectancy of the UVX bulb, or decrease the efficiency of the radiant catalytic ionization reaction. With respect to the temperature sensor, this sensor may be used to sense the temperature of the air and plasma output by the first module. The control circuitry may compare this output temperature with other signals or data and determine whether to turn OFF the UVX bulb. For example, if the HVAC system of the vehicle is set to high so as to cool the interior of the vehicle quickly to a predetermined cooler temperature set by a vehicle occupant, it may be advantageous to turn OFF the UVX bulb until there is an indication received by the control circuit 240 from other vehicle control circuitry 226 indicating that the interior of the vehicle is within about 2 to 10 degrees Fahrenheit of being at the predetermined cooler temperature set the vehicle occupant.
[0074] With respect to the air flow rate sensor, this sensor may provide feedback to the control circuit 240 so that the power to the UVX bulb 230 is increased or decreased in order to produce more or less UV output depending of the estimated flow rate of the air through the first module 210 . Additionally, if the flow rate sensor determines that the flow rate is below predetermined flow rate (perhaps due to a fan malfunction in the HVAC system, or if a temperature sensor senses that the temperature in or about the first module is above a predetermined safe maximum temperature, the control circuitry may turn the UVX bulb OFF.
[0075] In additional embodiments, the UVX bulb 230 may be comprised of a plurality of UVX light emitting diodes (LEDs) positioned within the first module so as to illuminate the surfaces of the air permeable structures 250 , 252 in order to generate the purifying plasma via radiant catalytic ionization.
[0076] In this context, when the air conditioning or HVAC system is switched ON, the UVX lamp 230 is lit, thus bringing about the transformation of air passing through or about the first module 210 into purifying plasma composed of hydroxyl radicals and hydrogen peroxide. The purifying plasma can be applied according to the ventilation speeds of the air conditioning system of automobiles, and its respective resources, depending on the vehicle.
[0077] Moreover, the equipment 200 can also be applied or installed to be a component of air conditioning or HVAC systems of other land, sea or air vehicles such as, for example, trains, subways, boats, airplanes, or construction or agricultural vehicles.
[0078] It will be appreciated by those skilled in the art having the benefit of this disclosure that this equipment for sanitizing the air conditioning system of vehicles by means of radiant catalytic ionization provides a system and device that can be incorporated into or used in conjunction with a HVAC system to significantly reduce the concentration of fungi, bacteria, volatile organic compounds (VOCs) carbon monoxide, and particulate matter and in effect clean the ducts, air and interior surfaces of a vehicle. It should be understood that the drawings and detailed description herein are to be regarded in an illustrative rather than a restrictive manner, and are not intended to be limiting to the particular forms and examples disclosed. On the contrary, included are any further modifications, changes, rearrangements, substitutions, alternatives, design choices, and embodiments apparent to those of ordinary skill in the art, without departing from the spirit and scope hereof, as defined by the following claims. Thus, it is intended that the following claims be interpreted to embrace all such further modifications, changes, rearrangements, substitutions, alternatives, design choices, and embodiments. | An air sanitization device is provided that utilizes radiant catalytic ionization to produce purifying plasma comprising highly oxidative molecules that greatly decrease the amount of volatile organic compounds, carbon monoxide and particulate matter within the HVAC system and the interior of transportation vehicle. The air sanitation device includes surfaces coated or impregnated with a noble alloy that comprises predominately titanium dioxide and a UV light source that directs UV light onto the surfaces of coated surfaces to generate, via the radiant catalytic ionization reaction the purifying plasma. Integration of the air sanitization device into a vehicle HVAC system greatly decreases irritant molecules within the vehicle. | 0 |
RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 13/293,985, filed Nov. 10, 2011, which is a continuation of PCT Application Serial No. PCT/US2010/035331, filed May 18, 2010, which claimed priority to U.S. Provisional Application Ser. No. 61/179,995, filed May 20, 2009, U.S. Provisional Application Ser. No. 61/218,832, filed Jun. 19, 2009, and U.S. Provisional Application Ser. No. 61/226,877, filed Jul. 20, 2009. The complete disclosure of each of these applications is hereby incorporated by reference herein.
BACKGROUND
Processing hydrocarbon-containing materials can permit useful intermediates or products to be extracted from the materials. Natural hydrocarbon-containing materials can include a variety of other substances in addition to hydrocarbons.
SUMMARY
Systems and methods are disclosed herein for processing a wide variety of different hydrocarbon-containing materials, such as light and heavy crude oils, natural gas, bitumen, coal, and such materials intermixed with and/or adsorbed onto a solid support, such as an inorganic support. In particular, the systems and methods disclosed herein can be used to process (e.g., crack, convert, isomerize, reform, separate) hydrocarbon-containing materials that are generally thought to be less easily processed, including oil sands, oil shale, tar sands, and other naturally-occurring and synthetic materials that include both hydrocarbon components and solid matter (e.g., solid organic and/or inorganic matter).
Such materials can be especially difficult to mix with liquids, e.g., with water or a solvent system during processing. For example, if the materials are low density, the materials tend to float to the surface of the liquid, or if the materials are high density they tend to sink to the bottom of the mixing vessel, rather than being dispersed. In some cases, the materials can be hydrophobic, highly crystalline, or otherwise difficult to wet. At the same time, it is desirable to process the feedstock in a relatively high solids level dispersion, for efficiency and in order to obtain a high final concentration of the desired product after processing.
The inventors have found that dispersion of a feedstock in a liquid mixture can be enhanced, and as a result in some cases the solids level of the mixture can be increased, by the use of certain mixing techniques and equipment. The mixing techniques and equipment disclosed herein also enhance mass transfer. In particular, jet mixing techniques, including for example jet aeration and jet flow agitation, have been found to provide good wetting, dispersion and mechanical disruption. By increasing the solids level of the mixture, the process can proceed more rapidly, more efficiently and more cost-effectively, and the resulting concentration of the intermediate or product can be increased.
In some implementations, the process further includes treating the feedstock to facilitate recovery of the hydrocarbon. For example, exposure of the materials to particle beams (e.g., beams that include ions and/or electrons and/or neutral particles) or high energy photons (e.g., x-rays or gamma rays) can be used to process the materials. Particle beam exposure can be combined with other techniques such as sonication, mechanical processing, e.g., comminution (for example size reduction), temperature reduction and/or cycling, pyrolysis, chemical processing (e.g., oxidation and/or reduction), and other techniques to further break down, isomerize, or otherwise change the molecular structure of the hydrocarbon components, to separate the components, and to extract useful materials from the components (e.g., directly from the components and/or via one or more additional steps in which the components are converted to other materials). Radiation may be applied from a device that is in a vault. Methods of treating hydrocarbon-containing materials are described in detail in U.S. patent application Ser. Nos. 12/417,786 and 12/417,699, both of which were filed on Apr. 3, 2009, the complete disclosures of which are incorporated herein by reference.
The systems and methods disclosed herein also provide for the combination of any hydrocarbon-containing materials described herein with additional materials including, for example, solid supporting materials. Solid supporting materials can increase the effectiveness of various material processing techniques. Further, the solid supporting materials can themselves act as catalysts and/or as hosts for catalyst materials such as noble metal particles, e.g., rhodium particles, platinum particles, and/or iridium particles. The catalyst materials can increase still further the rates and selectivity with which particular intermediates or products are obtained from processing the hydrocarbon-containing materials. Such additional materials and their use in processing are described in the above-incorporated U.S. patent application Ser. No. 12/417,786.
Many of the intermediates or products obtained by the methods disclosed herein, such as petroleum products, can be utilized directly as a fuel or as a blend with other components for powering cars, trucks, tractors, ships or trains. The hydrocarbon products can be further processed via conventional hydrocarbon processing methods. Where hydrocarbons were previously associated with solid components in materials such as oil sands, tar sands, and oil shale, the liberated hydrocarbons are flowable and are therefore amenable to processing in refineries.
In one aspect, the invention features a method that includes processing a hydrocarbon-containing feedstock by mixing the feedstock with a liquid medium in a vessel, using a jet mixer.
Some embodiments include one or more of the following features. The jet mixer may include, for example, a jet-flow agitator, a jet aeration type mixer, or a suction chamber jet mixer. If a jet aeration type mixer is used, it may be used without injection of air through the mixer. For example, if the jet aeration type mixer includes a nozzle having a first inlet line and a second inlet line, in some cases both inlet lines are supplied with a liquid. In some cases, mixing comprises adding the feedstock to the liquid medium in increments and mixing between additions. The mixing vessel may be, for example, a tank, rail car or tanker truck. The method may further include adding an emulsifier or surfactant to the mixture in the vessel.
In some instances, the vessel is or includes a conduit or other structure or carrier for the feedstock. For example, a jet mixer may be disposed in a conduit, e.g., between processing areas. In this case, the jet mixer can serve the dual purpose of mixing and conveying the mixture from one area to another. Additional jet mixers can be disposed in other areas, e.g., in one or more processing tanks, if desired. In some cases, the vessel can be a continuous loop of pipe, tubing, or other structure that defines a bore or lumen, and jet mixing can take place within this loop.
In another aspect, the invention features processing a hydrocarbon-containing feedstock by mixing the feedstock with a liquid medium in a vessel, using a mixer that produces generally toroidal flow within the vessel.
In some embodiments, the mixer is configured to limit any increase in the overall temperature of the liquid medium to less than 5° C. over the course of mixing. This aspect may also include, in some embodiments, any of the features discussed above.
In another aspect, the invention features an apparatus that includes a tank, a jet mixer having a nozzle disposed within the tank, and a delivery device configured to deliver a hydrocarbon-containing feedstock to the tank.
Some embodiments include one or more of the following features. The jet mixer can further include a motor, and the apparatus can further include a device configured to monitor the torque on the motor during mixing. The apparatus can also include a controller that adjusts the operation of the feedstock delivery device based on input from the torque-monitoring device.
All publications, patent applications, patents, and other references mentioned herein or attached hereto are incorporated by reference in their entirety for all that they contain.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram showing a sequence of steps for processing hydrocarbon-containing materials.
FIGS. 2 and 2A are diagrams illustrating jet flow exiting a nozzle.
FIG. 3 is a diagrammatic perspective view of a jet-flow agitator according to one embodiment. FIG. 3A is an enlarged perspective view of the impeller and jet tube of the jet-flow agitator of FIG. 3 . FIG. 3B is an enlarged perspective view of an alternate impeller.
FIG. 4 is a diagram of a suction chamber jet mixing nozzle according to one embodiment. FIG. 4A is a perspective view of a suction chamber jet mixing system according to another embodiment.
FIG. 5 is a diagrammatic perspective view of a jet mixing nozzle for a suction chamber jet mixing system according to another alternate embodiment.
FIG. 6 is a diagrammatic perspective view of a tank and a jet aeration type mixing system positioned in the tank, with the tank being shown as transparent to allow the jet mixer and associated piping to be seen. FIG. 6A is a perspective view of the jet mixer used in the jet aeration system of FIG. 6 . FIG. 6B is a diagrammatic perspective view of a similar system in which an air intake is provided.
FIG. 7 is a cross-sectional view of a jet aeration type mixer according to one embodiment.
FIG. 8 is a cross-sectional view of a jet aeration type mixer according to an alternate embodiment.
FIGS. 9-11 are diagrams illustrating alternative flow patterns in tanks containing different configurations of jet mixers.
FIG. 12 is a diagram illustrating the flow pattern that occurs in a tank during backflushing according to one embodiment.
FIG. 13 is a side view of a jet aeration type system according to another embodiment, showing a multi-level arrangement of nozzles in a tank.
FIGS. 14 and 14A are a diagrammatic top view and a perspective view, respectively, of a device that minimizes hold up along the walls of a tank during mixing.
FIGS. 15 and 16 are views of water jet devices that provide mixing while also minimizing hold up along the tank walls.
FIG. 17 is a cross-sectional view of a tank having a domed bottom and two jet mixers extending into the tank from above.
DETAILED DESCRIPTION
FIG. 1 shows a schematic diagram of a technique 100 for processing hydrocarbon-containing materials such as oil sands, oil shale, tar sands, and other materials that include hydrocarbons intermixed with solid components such as rock, sand, clay, silt, and/or solid organic material. These materials may be in their native form, or may have been previously treated, for example treated in situ with radiation as described below. In a first step of the sequence shown in FIG. 1 , the hydrocarbon-containing material 110 can be subjected to one or more optional mechanical processing steps 120 . The mechanical processing steps can include, for example, grinding, crushing, agitation, centrifugation, rotary cutting and/or chopping, shot-blasting, and various other mechanical processes that can reduce an average size of particles of material 110 , and initiate separation of the hydrocarbons from the remaining solid matter therein. In some embodiments, more than one mechanical processing step can be used. For example, multiple stages of grinding can be used to process material 110 . Alternatively, or in addition, a crushing process followed by a grinding process can be used to treat material 110 . Additional steps such as agitation and/or further crushing and/or grinding can also be used to further reduce the average size of particles of material 110 .
In a second step 130 of the sequence shown in FIG. 1 , the hydrocarbon-containing material 110 can be subjected to one or more optional cooling and/or temperature-cycling steps. In some embodiments, for example, material 110 can be cooled to a temperature at and/or below a boiling temperature of liquid nitrogen. More generally, the cooling and/or temperature-cycling in step 130 can include, for example, cooling to temperatures well below room temperature (e.g., cooling to 10° C. or less, 0° C. or less, −10° C. or less, −20° C. or less, −30° C. or less, −40° C. or less, −50° C. or less, −100° C. or less, −150° C. or less, −200° C. or less, or even lower temperatures). Multiple cooling stages can be performed, with varying intervals between each cooling stage to allow the temperature of material 110 to increase. The effect of cooling and/or temperature-cycling material 110 is to disrupt the physical and/or chemical structure of the material, promoting at least partial dissociation of the hydrocarbon components from the non-hydrocarbon components (e.g., solid non-hydrocarbon materials) in material 110 . Suitable methods and systems for cooling and/or temperature-cycling of material 110 are disclosed, for example, in U.S. Provisional Patent Application Ser. No. 61/081,709, filed on Jul. 17, 2008, and U.S. Ser. No. 12/502,629, filed Jul. 14, 2009, the entire contents of which are incorporated herein by reference.
In a third step 140 of the sequence of FIG. 1 , the hydrocarbon-containing material 110 can be exposed to charged particles or photons, such as photons having a wavelength between about 0.01 nm and 280 nm. In some embodiments, the photons can have a wavelength between, e.g., 100 nm to 280 nm or between 0.01 nm to 10 nm, or in some cases less than 0.01 nm. The charged particles interact with material 110 , causing further disassociation of the hydrocarbons therein from the non-hydrocarbon materials, and also causing various hydrocarbon chemical processes, including chain scission, bond-formation, and isomerization. These chemical processes convert long-chain hydrocarbons into shorter-chain hydrocarbons, many of which can eventually be extracted from material 110 as products and used directly for various applications. The chemical processes can also lead to conversion of various products into other products, some of which may be more desirable than others. For example, through bond-forming reactions, some short-chain hydrocarbons may be converted to medium-chain-length hydrocarbons, which can be more valuable products. As another example, isomerization can lead to the formation of straight-chain hydrocarbons from cyclic hydrocarbons. Such straight-chain hydrocarbons may be more valuable products than their cyclized counterparts.
By adjusting an average energy of the charged particles and/or an average current of the charged particles, the total amount of energy delivered or transferred to material 110 by the charged particles can be controlled. In some embodiments, for example, material 110 can be exposed to charged particles so that the energy transferred to material 110 (e.g., the energy dose applied to material 110 ) is 0.3 Mrad or more (e.g., 0.5 Mrad or more, 0.7 Mrad or more, 1.0 Mrad or more, 2.0 Mrad or more, 3.0 Mrad or more, 5.0 Mrad or more, 7.0 Mrad or more, 10.0 Mrad or more, 15.0 Mrad or more, 20.0 Mrad or more, 30.0 Mrad or more, 40.0 Mrad or more, 50.0 Mrad or more, 75.0 Mrad or more, 100.0 Mrad or more, 150.0 Mrad or more, 200.0 Mrad or more, 250.0 Mrad or more, or even 300.0 Mrad or more).
In general, electrons, ions, photons, and combinations of these can be used as the charged particles in step 140 to process material 110 . A wide variety of different types of ions can be used including, but not limited to, protons, hydride ions, oxygen ions, carbon ions, and nitrogen ions. These charged particles can be used under a variety of conditions; parameters such as particle currents, energy distributions, exposure times, and exposure sequences can be used to ensure that the desired extent of separation of the hydrocarbon components from the non-hydrocarbon components in material 110 , and the extent of the chemical conversion processes among the hydrocarbon components, is reached. Suitable systems and methods for exposing material 110 to charged particles are discussed, for example, in U.S. Ser. No. 12/417,699, filed Apr. 3, 2009, U.S. Ser. No. 12/486,436, filed Oct. 5, 2009, as well as the following U.S. Provisional Patent Applications: Ser. No. 61/049,406, filed on Apr. 30, 2008; Ser. No. 61/073,665, filed on Jun. 18, 2008; and Ser. No. 61/073,680, filed on Jun. 18, 2008. The entire contents of each of the foregoing applications is incorporated herein by reference. In particular, charged particle systems such as inductive linear accelerator (LINAC) systems can be used to deliver large doses of energy (e.g., doses of 50 Mrad or more) to material 110 .
In the final step of the processing sequence of FIG. 1 , the processed material 110 is subjected to a separation step 150 , which separates the hydrocarbon products 160 and the non-hydrocarbon products 170 . The separation step includes an extraction process that involves agitating the material 110 . For example, tar sands are processed using a hot water extraction process. After mining, the tar sands are transported to an extraction plant, where the hot water extraction process separates bitumen from sand, water and minerals. Hot water is added to the sand, and the resulting slurry is agitated. The combination of hot water and agitation releases bitumen from the oil sand in the form of droplets. Air bubbles attach to the bitumen droplets, causing the droplets to float to the top of the separation tank. The bitumen is then skimmed off and processed to remove residual water and solids. During this extraction process, agitation is performed using the jet mixing techniques discussed below.
A wide variety of other processing steps can optionally be used to further separate and refine the products. Exemplary processes include, but are not limited to, distillation, centrifugation and filtering.
The processing sequence shown in FIG. 1 is a flexible sequence, and can be modified as desired for particular materials 110 and/or to recover particular hydrocarbon products 160 . For example, the order of the various steps can be changed in FIG. 1 . Further, additional steps of the types shown, or other types of steps, can be included at any point within the sequence, as desired. For example, additional mechanical processing steps, cooling/temperature-cycling steps, particle beam exposure steps, and/or separation steps can be included at any point in the sequence. Further, other processing steps such as sonication, chemical processing, pyrolysis, oxidation and/or reduction, and radiation exposure can be included in the sequence shown in FIG. 1 prior to, during, and/or following any of the steps shown in FIG. 1 . Many processes suitable for inclusion in the sequence of FIG. 1 are discussed, for example, in PCT Publication No. WO 2008/073186 (e.g., throughout the Detailed Description section).
Suitable liquids that can be added to material 110 , e.g., during extraction, include, for example, water, various types of liquid hydrocarbons (e.g., hydrocarbon solvents), and other common organic and inorganic solvents.
Agitation
Jet Mixing Characteristics
Various types of mixing devices which may be used during hydrocarbon processing are described below. Other mixing devices having similar characteristics may be used. Suitable mixers have in common that they produce high velocity circulating flow, for example flow in a toroidal or elliptical pattern. Generally, preferred mixers exhibit a high bulk flow rate. Preferred mixers provide this mixing action with relatively low energy consumption. It is also preferred in some cases that the mixer produce relatively low shear and avoid heating of the liquid medium. As will be discussed in detail below, some preferred mixers draw the mixture through an inlet into a mixing element, which may include a rotor or impeller, and then expel the mixture from the mixing element through an outlet nozzle. This circulating action, and the high velocity of the jet exiting the nozzle, assist in dispersing material that is floating on the surface of the liquid or material that has settled to the bottom of the tank, depending on the orientation of the mixing element. Mixing elements can be positioned in different orientations to disperse both floating and settling material, and the orientation of the mixing elements can in some cases be adjustable.
For example, in some preferred mixing systems the velocity v o of the jet as meets the ambient fluid is from about 2 to 300 m/s, e.g., about 5 to 150 m/s or about 10 to 100 m/s. The power consumption of the mixing system may be about 20 to 1000 KW, e.g., 30 to 570 KW, 50 to 500 KW, or 150 to 250 KW for a 100,000 L tank. It is generally preferred that the power usage be low for cost-effectiveness.
Jet mixing involves the discharge of a submerged jet, or a number of submerged jets, of high velocity liquid into a fluid medium, in this case the mixture of feedstock and liquid medium. The jet of liquid penetrates the fluid medium, with its energy being dissipated by turbulence and some initial heat. This turbulence is associated with velocity gradients (fluid shear). The surrounding fluid is accelerated and entrained into the jet flow, with this secondary entrained flow increasing as the distance from the jet nozzle increases. The momentum of the secondary flow remains generally constant as the jet expands, as long as the flow does not hit a wall, floor or other obstacle. The longer the flow continues before it hits any obstacle, the more liquid is entrained into the secondary flow, increasing the bulk flow in the tank or vessel. When it encounters an obstacle, the secondary flow will lose momentum, more or less depending on the geometry of the tank, e.g., the angle at which the flow impinges on the obstacle. It is generally desirable to orient the jets and/or design the tank so that hydraulic losses to the tank walls are minimized. For example, it may be desirable for the tank to have an arcuate bottom (e.g., a domed headplate), and for the jet mixers to be oriented relatively close to the sidewalls, as shown in FIG. 17 . The tank bottom (lower head plate) may have any desired domed configuration, or may have an elliptical or conical geometry.
Jet mixing differs from most types of liquid/liquid and liquid/solid mixing in that the driving force is hydraulic rather than mechanical. Instead of shearing fluid and propelling it around the mixing vessel, as a mechanical agitator does, a jet mixer forces fluid through one or more nozzles within the tank, creating high-velocity jets that entrain other fluid. The result is shear (fluid against fluid) and circulation, which mix the tank contents efficiently.
Referring to FIG. 2 , the high velocity gradient between the core flow from a submerged jet and the surrounding fluid causes eddies. FIG. 2A illustrates the general characteristics of a submerged jet. As the submerged jet expands into the surrounding ambient environment the velocity profile flattens as the distance (x) from the nozzle increases. Also, the velocity gradient dv/dr changes with r (the distance from the centerline of the jet) at a given distance x, such that eddies are created which define the mixing zone (the conical expansion from the nozzle).
In an experimental study of a submerged jet in air (the results of which are applicable to any fluid, including water), Albertson et al. (“Diffusion of Submerged Jets,” Paper 2409, Amer. Soc. of Civil Engineers Transactions, Vol. 115:639-697, 1950, at p. 657) developed dimensionless relationships for v(x) r=0 /v o (centerline velocity), v(r) x /v(x) r=0 (velocity profile at a given x), Q x /Q o (flow entrainment), and E x /E o (energy change with x):
(1) Centerline velocity, v(x) r=0 /v o :
v
(
r
=
0
)
v
o
x
D
o
=
6.2
(2) velocity profile at any x, v(r) x /v(x) r=0 :
log
[
v
(
r
)
x
v
o
x
D
]
=
0.79
-
33
r
2
x
2
(3) Flow and energy at any x:
Q x Q o = 0.32 20 x D o ( 10.21 ) E x E o = 4.1 D o x ( 10.22 )
where:
v(r=0)=centerline velocity of submerged jet (m/s), v o =velocity of jet as it emerges from the nozzle (m/s), x=distance from nozzle (m), r=distance from centerline of jet (m), D o =diameter of nozzle (m), Q x =flow of fluid across any given plane at distance x from the nozzle (me/s), Q o =flow of fluid emerging from the nozzle (m3/s), E=energy flux of fluid across any given plane at distance x from the nozzle (m 3 /s), E o =energy flux of fluid emerging from the nozzle (m 3 /s).
(“Water Treatment Unit Processes: Physical and Chemical,” David W. Hendricks, CRC Press 2006, p. 411.)
Jet mixing is particularly cost-effective in large-volume (over 1,000 gal) and low-viscosity (under 1,000 cPs) applications. It is also generally advantageous that in most cases a jet mixer has no moving parts submerged, e.g., when a pump is used it is generally located outside the vessel.
One advantage of jet mixing is that the temperature of the ambient fluid (other than directly adjacent the exit of the nozzle, where there may be some localized heating) is increased only slightly if at all. For example, the temperature may be increased by less than 5° C., less than 1° C., or not to any measurable extent.
Jet-Flow Agitators
One type of jet-flow agitator is shown in FIGS. 3-3A . This type of mixer is available commercially, e.g., from IKA under the tradename ROTOTRON™. Referring to FIG. 3 , the mixer 200 includes a motor 202 , which rotates a drive shaft 204 . A mixing element 206 is mounted at the end of the drive shaft 204 . As shown in FIG. 3A , the mixing element 206 includes a shroud 208 and, within the shroud, an impeller 210 . As indicated by the arrows, when the impeller is rotated in its “forward” direction, the impeller 210 draws liquid in through the open upper end 212 of the shroud and forces the liquid out through the open lower end 214 . Liquid exiting end 214 is in the form of a high velocity stream or jet. If the direction of rotation of the impeller 210 is reversed, liquid can be drawn in through the lower end 214 and ejected through the upper end 212 . This can be used, for example, to suck in solids that are floating near or on the surface of the liquid in a tank or vessel. (It is noted that “upper” and “lower” refer to the orientation of the mixer in FIG. 3 ; the mixer may be oriented in a tank so that the upper end is below the lower end.)
The shroud 208 includes flared areas 216 and 218 adjacent its ends. These flared areas are believed to contribute to the generally toroidal flow that is observed with this type of mixer. The geometry of the shroud and impeller also concentrate the flow into a high velocity stream using relatively low power consumption.
Preferably, the clearance between the shroud 208 and the impeller 210 is sufficient so as to avoid excessive milling of the material as it passes through the shroud. For example, the clearance may be at least 10 times the average particle size of the solids in the mixture, preferably at least 100 times.
In some implementations, the shaft 204 is configured to allow gas delivery through the shaft. For example, the shaft 204 may include a bore (not shown) through which gas is delivered, and one or more orifices through which gas exits into the mixture. The orifices may be within the shroud 208 , to enhance mixing, and/or at other locations along the length of the shaft 204 .
The impeller 210 may have any desired geometry that will draw liquid through the shroud at a high velocity. The impeller is preferably a marine impeller, as shown in FIG. 3A , but may have a different design, for example, a Rushton impeller as shown in FIG. 3B , or a modified Rushton impeller, e.g., tilted so as to provide some axial flow.
In order to generate the high velocity flow through the shroud, the motor 202 is preferably a high speed, high torque motor, e.g., capable of operating at 500 to 20,000 RPM, e.g., 3,000 to 10,000 RPM. However, the larger the mixer (e.g., the larger the shroud and/or the larger the motor) the lower the rotational speed can be. Thus, if a large mixer is used, such as a 5 hp, 10 hp, 20 hp, or 30 hp or greater, the motor may be designed to operate at lower rotational speeds, e.g., less than 2000 RPM, less than 1500 RPM, or even 500 RPM or less. For example, a mixer sized to mix a 10,000-20,000 liter tank may operate at speeds of 900 to 1,200 RPM. The torque of the motor is preferably self-adjusting, to maintain a relatively constant impeller speed as the mixing conditions change over time.
Advantageously, the mixer can be oriented at any desired angle or location in the tank, to direct the jet flow in a desired direction. Moreover, as discussed above, depending on the direction of rotation of the impeller the mixer can be used to draw fluid from either end of the shroud.
In some implementations, two or more jet mixers are positioned in the vessel, with one or more being configured to jet fluid upward (“up pump”) and one or more being configured to jet fluid downward (“down pump”). In some cases, an up pumping mixer will be positioned adjacent a down pumping mixer, to enhance the turbulent flow created by the mixers. If desired, one or more mixers may be switched between upward flow and downward flow during processing. It may be advantageous to switch all or most of the mixers to up pumping mode during initial dispersion of the feedstock in the liquid medium, as up pumping creates significant turbulence at the surface.
Suction Chamber Jet Mixers
Another type of jet mixer includes a primary nozzle that delivers a pressurized fluid from a pump, a suction inlet adjacent the primary nozzle through which ambient fluid is drawn by the pressure drop between the primary nozzle and the wider inlet, and a suction chamber extending between the suction inlet and a secondary nozzle. A jet of high velocity fluid exits the secondary nozzle.
An example of this type of mixer is shown in FIG. 4 . As shown, in mixer 600 pressurized liquid from a pump (not shown) flows through an inlet passage 602 and exits through a primary nozzle 603 . Ambient liquid is drawn through a suction inlet 604 into suction chamber 606 by the pressure drop caused by the flow of pressurized liquid. The combined flow exits from the suction chamber into the ambient liquid at high velocity through secondary nozzle 608 . Mixing occurs both in the suction chamber and in the ambient liquid due to the jet action of the exiting jet of liquid.
A mixing system that operates according to a similar principle is shown in FIG. 4A . Mixers embodying this design are commercially available from ITT Water and Wastewater, under the tradename Flygt™ jet mixers. In system 618 , pump 620 generates a primary flow that is delivered to the tank (not shown) through a suction nozzle system 622 . The suction nozzle system 622 includes a primary nozzle 624 which functions in a manner similar to primary nozzle 603 described above, causing ambient fluid to be drawn into the adjacent open end 626 of ejector tube 628 due to the pressure drop induced by the fluid exiting the primary nozzle. The combined flow then exits the other end 630 of ejector tube 628 , which functions as a secondary nozzle, as a high velocity jet.
The nozzle shown in FIG. 5 , referred to as an eductor nozzle, operates under a similar principle. A nozzle embodying this design is commercially available under the tradename TeeJet®. As shown, in nozzle 700 pressurized liquid flows in through an inlet 702 and exits a primary nozzle 704 , drawing ambient fluid in to the open end 706 of a diffuser 708 . The combined flow exits the opposite open end 710 of the diffuser at a circulation flow rate A+B that is the sum of the inlet flow rate A and the flow rate B of the entrained ambient fluid.
Jet Aeration Type Mixers
Another type of jet mixing system that can be utilized is referred to in the wastewater industry as “jet aeration mixing.” In the wastewater industry, these mixers are typically used to deliver a jet of a pressurized air and liquid mixture, to provide aeration. However, in the present application in some cases the jet aeration type mixers are utilized without pressurized gas, as will be discussed below. The principles of operation of jet aeration mixers will be initially described in the context of their use with pressurized gas, for clarity.
An eddy jet mixer, such as the mixer 800 shown in FIGS. 6-6B , includes multiple jets 802 mounted in a radial pattern on a central hub 804 . The radial pattern of the jets uniformly distributes mixing energy throughout the tank. The eddy jet mixer may be centrally positioned in a tank, as shown to provide toroidal flow about the center axis of the tank. The eddy jet mixer may be mounted on piping 806 , which supplies high velocity liquid to the eddy jet mixer. In the embodiment shown in FIG. 6B , air is also supplied to the eddy jet mixer through piping 812 . The high velocity liquid is delivered by a pump 808 which is positioned outside of the tank and which draws liquid in through an inlet 810 in the side wall of the tank.
FIGS. 7 and 8 show two types of nozzle configurations that are designed to mix a gas and a liquid stream and eject a high velocity jet. These nozzles are configured somewhat differently from the eddy jet mixer shown in FIGS. 6 and 6A but function in a similar manner. In the system 900 shown in FIG. 7 , a primary or motive fluid is directed through a liquid line 902 to inner nozzles 904 through which the liquid travels at high velocity into a mixing area 906 . A second fluid, e.g., a gas, such as compressed air, nitrogen or carbon dioxide, or a liquid, enters the mixing area through a second line 908 and entrained in the motive fluid entering the mixing area 906 through the inner nozzles. In some instances the second fluid is nitrogen or carbon dioxide so as to reduce oxidation of the enzyme. The combined flow from the two lines is jetted into the mixing tank through the outer nozzles 910 . If the second fluid is a gas, tiny bubbles are entrained in the liquid in the mixture. Liquid is supplied to the liquid line 902 by a pump. Gas, if it is used, is provided by compressors. If a liquid is used as the second fluid, it can have the same velocity as the liquid entering through the liquid line 902 , or a different velocity.
FIG. 8 shows an alternate nozzle design 1000 , in which outer nozzles 1010 (of which only one is shown) are positioned along the length of an elongated member 1011 that includes a liquid line 1002 that is positioned parallel to a second line 1008 . Each nozzle includes a single outer nozzle 1010 and a single inner nozzle 1004 . Mixing of the motive liquid with the second fluid proceeds in the same manner as in the system 900 described above.
FIGS. 9 and 10 illustrate examples of jet aeration type mixing systems in which nozzles are positioned along the length of an elongated member. In the example shown in FIG. 9 , the elongated member 1102 is positioned along the diameter of the tank 1104 , and the nozzles 1106 extend in opposite directions from the nozzle to produce the indicated flow pattern which includes two areas of generally elliptical flow, one on either side of the central elongated member. In the example shown in FIG. 10 , the tank 1204 is generally rectangular in cross section, and the elongated member 1202 extends along one side wall 1207 of the tank. In this case, the nozzles 1206 all face in the same direction, towards the opposite side wall 1209 . This produces the flow pattern shown, in which flow in the tank is generally elliptical about a major axis extending generally centrally along the length of the tank. In the embodiment shown in FIG. 10 , the nozzles may be canted towards the tank floor, e.g., at an angle of from about 15 to 30 degrees from the horizontal.
In another embodiment, shown in FIG. 11 , the nozzles 1302 , 1304 , and suction inlet 1306 are arranged to cause the contents of the tank to both revolve and rotate in a toroidal, rolling donut configuration around a central vertical axis of the tank. Flow around the surface of the toroid is drawn down the tank center, along the floor, up the walls and back to the center, creating a rolling helix pattern, which sweeps the center and prevents solids from settling. The toroidal pattern is also effective in moving floating solids to the tank center where they are pulled to the bottom and become homogenous with the tank contents. The result is a continuous helical flow pattern, which minimizes tank dead spots.
Backflushing
In some instances, the jet nozzles described herein can become plugged, which may cause efficiency and cost effectiveness to be reduced. Plugging of the nozzles may be removed by reversing flow of the motive liquid through the nozzle. For example, in the system shown in FIG. 12 , this is accomplished by closing a valve 1402 between the pump 1404 and the liquid line 1406 flowing to the nozzles 1408 , and activating a secondary pump 1410 . Secondary pump 1410 draws fluid in through the nozzles. The fluid then travels up through vertical pipe 1412 due to valve 1402 being closed. The fluid exits the vertical pipe 1412 at its outlet 1414 for recirculation through the tank.
Mixing in Transit/Portable Mixers
In some cases processing can take place in part or entirely during transportation of the mixture, e.g., between a first processing plant for treating the feedstock and a second processing plant for production of a final product. In this case, mixing can be conducted using a jet mixer designed for rail car or other portable use. The mixer can be operated using a control system that is external to the tank, which may include for example a motor and a controller configured to control the operation of the mixer. Venting (not shown) may also be provided.
Minimizing Hold Up on Tank Walls
In some situations, in particular at solids levels approaching a theoretical or practical limit, material may accumulate along the side wall and/or bottom wall of the tank during mixing. This phenomenon, referred to as “hold up,” is undesirable as it can result in inadequate mixing. Several approaches can be taken to minimize hold up and ensure good mixing throughout the tank.
For example, in addition to the jet mixing device(s), the tank can be outfitted with a scraping device, for example a device having a blade that scrapes the side of the tank in a “squeegee” manner. Such devices are well known, for example in the dairy industry. Suitable agitators include the side and bottom sweep agitators and scraper blade agitators manufactured by Walker Engineered Products, New Lisbon, Wis. As shown in FIG. 14 , a side and bottom sweep agitator 1800 may include a central elongated member 1802 , mounted to rotate about the axis of the tank. Side wall scraper blades 1804 are mounted at each end of the elongated member 1802 and are disposed at an angle with respect to the elongated member. In the embodiment shown, a pair of bottom wall scraper blades 1806 are mounted at an intermediate point on the elongated member 1802 , to scrape up any material accumulating on the tank bottom. These scrapers may be omitted if material is not accumulating on the tank bottom. As shown in FIG. 14A , the scraper blades 1804 may be in the form of a plurality of scraper elements positioned along the side wall. In other embodiments, the scraper blades are continuous, or may have any other desired geometry.
In other embodiments, the jet mixer itself is configured so as to minimize hold up. For example, the jet mixer may include one or more movable heads and/or flexible portions that move during mixing. For example, the jet mixer may include an elongated rotatable member having a plurality of jet nozzles along its length. The elongated member may be planar, as shown in FIG. 15 , or have a non-planar shape, e.g., it may conform to the shape of the tank walls as shown in FIG. 16 .
Referring to FIG. 15 , the jet mixer nozzles may be positioned on a rotating elongated member 1900 that is driven by a motor 1902 and shaft 1904 . Water or other fluid is pumped through passageways in the rotating member, e.g., by a pump impeller 1906 , and exits as a plurality of jets through jet orifices 1908 while the member 1900 rotates. To reduce hold up on the tank side walls, orifices 1910 may be provided at the ends of the member 1900 .
In the embodiment shown in FIG. 16 , to conform to the particular shape of the tank 2000 the elongated member includes horizontally extending arms 2002 , downwardly inclined portions 2004 , outwardly and upwardly inclined portions 2006 , and vertically extending portions 2008 . Fluid is pumped through passageways within the elongated member to a plurality of jet orifices 38 , through which jets are emitted while the elongated member is rotated.
In both of the embodiments shown in FIGS. 15 and 16 , the jets provide mixing while also washing down the side walls of the tank.
In some implementations, combinations of the embodiments described above may be used. For example, combinations of planar and non-planar rotating or oscillating elongated members may be used. The moving nozzle arrangements described above can be used in combination with each other and/or in combination with scrapers. A plurality of moving nozzle arrangements can be used together, for example two or more of the rotating members shown in FIG. 15 can be stacked vertically in the tank. When multiple rotating members are used, they can be configured to rotate in the same direction or in opposite directions, and at the same speed or different speeds.
Physical Treatment of Feedstock
In some implementations, the feedstock is physically treated, e.g., to change its molecular structure. Physical treatment processes can include one or more of any of those described herein, such as mechanical treatment, chemical treatment, irradiation, sonication, oxidation, pyrolysis or steam explosion. Treatment methods can be used in combinations of two, three, four, or even all of these technologies (in any order). When more than one treatment method is used, the methods can be applied at the same time or at different times. Other processes that change a molecular structure of a feedstock may also be used, alone or in combination with the processes disclosed herein.
Mechanical Treatments
In some cases, methods can include a mechanical treatment. Mechanical treatments include, for example, cutting, milling, pressing, grinding, shearing and chopping. Milling may include, for example, ball milling, hammer milling, rotor/stator dry or wet milling, or other types of milling. Other mechanical treatments include, e.g., stone grinding, cracking, mechanical ripping or tearing, pin grinding or air attrition milling.
In some implementations, the feedstock material can first be physically treated by one or more of the other physical treatment methods, e.g., chemical treatment, radiation, sonication, oxidation, pyrolysis or steam explosion, and then mechanically treated. This sequence can be advantageous since materials treated by one or more of the other treatments, e.g., irradiation or pyrolysis, tend to be more brittle and, therefore, it may be easier to further change the molecular structure of the material by mechanical treatment.
Feed preparation systems can be configured to produce streams with specific characteristics such as, for example, specific maximum sizes or specific surface areas.
Radiation Treatment
Irradiation can reduce the molecular weight and/or crystallinity of feedstock. In some embodiments, energy deposited in a material that releases an electron from its atomic orbital is used to irradiate the materials. The radiation may be provided by 1) heavy charged particles, such as alpha particles or protons, 2) electrons, produced, for example, in beta decay or electron beam accelerators, or 3) electromagnetic radiation, for example, gamma rays, x rays, or ultraviolet rays. In one approach, radiation produced by radioactive substances can be used to irradiate the feedstock. In some embodiments, any combination in any order or concurrently of (1) through (3) may be utilized. In another approach, electromagnetic radiation (e.g., produced using electron beam emitters) can be used to irradiate the feedstock. The doses applied depend on the desired effect and the particular feedstock. For example, high doses of radiation can break chemical bonds within feedstock components. In some instances when chain scission is desirable and/or polymer chain functionalization is desirable, particles heavier than electrons, such as protons, helium nuclei, argon ions, silicon ions, neon ions, carbon ions, phosphorus ions, oxygen ions or nitrogen ions can be utilized. When ring-opening chain scission is desired, positively charged particles can be utilized for their Lewis acid properties for enhanced ring-opening chain scission. For example, when maximum oxidation is desired, oxygen ions can be utilized, and when maximum nitration is desired, nitrogen ions can be utilized.
Ionizing Radiation
Each form of radiation ionizes the carbon-containing material via particular interactions, as determined by the energy of the radiation. Heavy charged particles primarily ionize matter via Coulomb scattering; furthermore, these interactions produce energetic electrons that may further ionize matter. Alpha particles are identical to the nucleus of a helium atom and are produced by the alpha decay of various radioactive nuclei, such as isotopes of bismuth, polonium, astatine, radon, francium, radium, several actinides, such as actinium, thorium, uranium, neptunium, curium, californium, americium, and plutonium.
When particles are utilized, they can be neutral (uncharged), positively charged or negatively charged. When charged, the charged particles can bear a single positive or negative charge, or multiple charges, e.g., one, two, three or even four or more charges. In instances in which chain scission is desired, positively charged particles may be desirable, in part due to their acidic nature. When particles are utilized, the particles can have the mass of a resting electron, or greater, e.g., 500, 1000, 1500, 2000, 10,000 or even 100,000 times the mass of a resting electron. For example, the particles can have a mass of from about 1 atomic unit to about 150 atomic units, e.g., from about 1 atomic unit to about 50 atomic units, or from about 1 to about 25, e.g., 1, 2, 3, 4, 5, 10, 12 or 15 amu. Accelerators used to accelerate the particles can be electrostatic DC, electrodynamic DC, RF linear, magnetic induction linear or continuous wave. For example, cyclotron type accelerators are available from IBA, Belgium, such as the Rhodotron® system, while DC type accelerators are available from RDI, now IBA Industrial, such as the Dynamitron®. Ions and ion accelerators are discussed in Introductory Nuclear Physics, Kenneth S. Krane, John Wiley & Sons, Inc. (1988), Krsto Prelec, FIZIKA B 6 (1997) 4, 177-206, Chu, William T., “Overview of Light-Ion Beam Therapy” Columbus-Ohio, ICRU-IAEA Meeting, 18-20 Mar. 2006, Iwata, Y. et al., “Alternating-Phase-Focused IH-DTL for Heavy-Ion Medical Accelerators” Proceedings of EPAC 2006, Edinburgh, Scotland and Leaner, C. M. et al., “Status of the Superconducting ECR Ion Source Venus” Proceedings of EPAC 2000, Vienna, Austria.
Gamma radiation has the advantage of a significant penetration depth into a variety of materials. Sources of gamma rays include radioactive nuclei, such as isotopes of cobalt, calcium, technicium, chromium, gallium, indium, iodine, iron, krypton, samarium, selenium, sodium, thalium, and xenon.
Sources of x rays include electron beam collision with metal targets, such as tungsten or molybdenum or alloys, or compact light sources, such as those produced commercially by Lyncean.
Sources for ultraviolet radiation include deuterium or cadmium lamps.
Sources for infrared radiation include sapphire, zinc, or selenide window ceramic lamps.
Sources for microwaves include klystrons, Slevin type RF sources, or atom beam sources that employ hydrogen, oxygen, or nitrogen gases.
In some embodiments, a beam of electrons is used as the radiation source. A beam of electrons has the advantages of high dose rates (e.g., 1, 5, or even 10 Mrad per second), high throughput, less containment, and less confinement equipment. Electrons can also be more efficient at causing chain scission. In addition, electrons having energies of 4-10 MeV can have a penetration depth of 5 to 30 mm or more, such as 40 mm.
Electron beams can be generated, e.g., by electrostatic generators, cascade generators, transformer generators, low energy accelerators with a scanning system, low energy accelerators with a linear cathode, linear accelerators, and pulsed accelerators. Electrons as an ionizing radiation source can be useful, e.g., for relatively thin piles of materials, e.g., less than 0.5 inch, e.g., less than 0.4 inch, 0.3 inch, 0.2 inch, or less than 0.1 inch. In some embodiments, the energy of each electron of the electron beam is from about 0.3 MeV to about 2.0 MeV (million electron volts), e.g., from about 0.5 MeV to about 1.5 MeV, or from about 0.7 MeV to about 1.25 MeV.
Electron beam irradiation devices may be procured commercially from Ion Beam Applications, Louvain-la-Neuve, Belgium or the Titan Corporation, San Diego, Calif. Typical electron energies can be 1 MeV, 2 MeV, 4.5 MeV, 7.5 MeV, or 10 MeV. Typical electron beam irradiation device power can be 1 kW, 5 kW, 10 kW, 20 kW, 50 kW, 100 kW, 250 kW, or 500 kW. The level of depolymerization of the feedstock depends on the electron energy used and the dose applied, while exposure time depends on the power and dose. Typical doses may take values of 1 kGy, 5 kGy, 10 kGy, 20 kGy, 50 kGy, 100 kGy, or 200 kGy.
Ion Particle Beams
Particles heavier than electrons can be utilized to irradiate hydrocarbon-containing materials. For example, protons, helium nuclei, argon ions, silicon ions, neon ions carbon ions, phosphorus ions, oxygen ions or nitrogen ions can be utilized. In some embodiments, particles heavier than electrons can induce higher amounts of chain scission (relative to lighter particles). In some instances, positively charged particles can induce higher amounts of chain scission than negatively charged particles due to their acidity.
Heavier particle beams can be generated, e.g., using linear accelerators or cyclotrons. In some embodiments, the energy of each particle of the beam is from about 1.0 MeV/atomic unit to about 6,000 MeV/atomic unit, e.g., from about 3 MeV/atomic unit to about 4,800 MeV/atomic unit, or from about 10 MeV/atomic unit to about 1,000 MeV/atomic unit.
In certain embodiments, ion beams can include more than one type of ion. For example, ion beams can include mixtures of two or more (e.g., three, four or more) different types of ions. Exemplary mixtures can include carbon ions and protons, carbon ions and oxygen ions, nitrogen ions and protons, and iron ions and protons. More generally, mixtures of any of the ions discussed above (or any other ions) can be used to form irradiating ion beams. In particular, mixtures of relatively light and relatively heavier ions can be used in a single ion beam.
In some embodiments, ion beams for irradiating materials include positively-charged ions. The positively charged ions can include, for example, positively charged hydrogen ions (e.g., protons), noble gas ions (e.g., helium, neon, argon), carbon ions, nitrogen ions, oxygen ions, silicon atoms, phosphorus ions, and metal ions such as sodium ions, calcium ions, and/or iron ions. Without wishing to be bound by any theory, it is believed that such positively-charged ions behave chemically as Lewis acid moieties when exposed to materials, initiating and sustaining cationic ring-opening chain scission reactions in an oxidative environment.
In certain embodiments, ion beams for irradiating materials include negatively-charged ions. Negatively charged ions can include, for example, negatively charged hydrogen ions (e.g., hydride ions), and negatively charged ions of various relatively electronegative nuclei (e.g., oxygen ions, nitrogen ions, carbon ions, silicon ions, and phosphorus ions). Without wishing to be bound by any theory, it is believed that such negatively-charged ions behave chemically as Lewis base moieties when exposed to materials, causing anionic ring-opening chain scission reactions in a reducing environment.
In some embodiments, beams for irradiating materials can include neutral atoms. For example, any one or more of hydrogen atoms, helium atoms, carbon atoms, nitrogen atoms, oxygen atoms, neon atoms, silicon atoms, phosphorus atoms, argon atoms, and iron atoms can be included in beams that are used for irradiation of hydrocarbon-containing materials. In general, mixtures of any two or more of the above types of atoms (e.g., three or more, four or more, or even more) can be present in the beams.
In certain embodiments, ion beams used to irradiate materials include singly-charged ions such as one or more of H + , H − , He + , Ne + , Ar + , C + , C − , O + , O − , N + , N − , Si + , Si + , P + , P − , Na + , Ca + , and Fe + . In some embodiments, ion beams can include multiply-charged ions such as one or more of C 2+ , C 3+ , C 4+ , N 3+ , N 5+ , N 3− , O 2+ , O 2− , O 2 2− , Si 2+ , Si 4+ , Si 2− , and Si 4− . In general, the ion beams can also include more complex polynuclear ions that bear multiple positive or negative charges. In certain embodiments, by virtue of the structure of the polynuclear ion, the positive or negative charges can be effectively distributed over substantially the entire structure of the ions. In some embodiments, the positive or negative charges can be somewhat localized over portions of the structure of the ions.
Electromagnetic Radiation
In embodiments in which the irradiating is performed with electromagnetic radiation, the electromagnetic radiation can have, e.g., energy per photon (in electron volts) of greater than 10 2 eV, e.g., greater than 10 3 , 10 4 , 10 5 , 10 6 , or even greater than 10 7 eV. In some embodiments, the electromagnetic radiation has energy per photon of between 10 4 and 10 7 , e.g., between 10 5 and 10 6 eV. The electromagnetic radiation can have a frequency of, e.g., greater than 10 16 Hz, greater than 10 17 Hz, 10 18 , 10 19 , 10 20 , or even greater than 10 21 Hz. In some embodiments, the electromagnetic radiation has a frequency of between 10 18 and 10 22 Hz, e.g., between 10 19 to 10 21 Hz.
Doses
In some embodiments, the irradiating (with any radiation source or a combination of sources) is performed until the material receives a dose of at least 0.25 Mrad, e.g., at least 1.0 Mrad, at least 2.5 Mrad, at least 5.0 Mrad, or at least 10.0 Mrad. In some embodiments, the irradiating is performed until the material receives a dose of between 1.0 Mrad and 6.0 Mrad, e.g., between 1.5 Mrad and 4.0 Mrad.
In some embodiments, the irradiating is performed at a dose rate of between 5.0 and 1500.0 kilorads/hour, e.g., between 10.0 and 750.0 kilorads/hour or between 50.0 and 350.0 kilorads/hours.
In some embodiments, two or more radiation sources are used, such as two or more ionizing radiations. For example, samples can be treated, in any order, with a beam of electrons, followed by gamma radiation and UV light having wavelengths from about 100 nm to about 280 nm. In some embodiments, samples are treated with three ionizing radiation sources, such as a beam of electrons, gamma radiation, and energetic UV light.
Sonication, Pyrolysis and Oxidation
In addition to radiation treatment, the feedstock may be treated with any one or more of sonication, pyrolysis and oxidation. These treatment processes are described in U.S. Ser. No. 12/417,840, the disclosure of which is incorporated by reference herein.
Other Processes
Any of the processes of this paragraph can be used alone without any of the processes described herein, or in combination with any of the processes described herein (in any order): steam explosion, acid treatment (including concentrated and dilute acid treatment with mineral acids, such as sulfuric acid, hydrochloric acid and organic acids, such as trifluoroacetic acid), base treatment (e.g., treatment with lime or sodium hydroxide), UV treatment, screw extrusion treatment (see, e.g., U.S. Patent Application Ser. No. 61/073,530, filed Nov. 18, 2008, solvent treatment (e.g., treatment with ionic liquids) and freeze milling (see, e.g., U.S. Patent Application Ser. No. 61/081,709).
Other Embodiments
A number of embodiments have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the disclosure.
For example, the jet mixers described herein can be used in any desired combination, and/or in combination with other types of mixers.
The jet mixer(s) may be mounted in any desired position within the tank. With regard to shaft-mounted jet mixers, the shaft may be collinear with the center axis of the tank or may be offset therefrom. For example, if desired the tank may be provided with a centrally mounted mixer of a different type, e.g., a marine impeller or Rushton impeller, and a jet mixer may be mounted in another area of the tank either offset from the center axis or on the center axis. In the latter case one mixer can extend from the top of the tank while the other extends upward from the floor of the tank. Moreover, as shown in FIG. 13 , two or more jet mixers can be mounted in a multi-level arrangement at different heights within the tank.
In any of the jet mixing systems described herein, the flow of fluid (liquid and/or gas) through the jet mixer can be continuous or pulsed, or a combination of periods of continuous flow with intervals of pulsed flow. When the flow is pulsed, pulsing can be regular or irregular. In the latter case, the motor that drives the fluid flow can be programmed, for example to provide pulsed flow at intervals to prevent mixing from becoming “stuck.” The frequency of pulsed flow can be, for example, from about 0.5 Hz to about 10 Hz, e.g., about 0.5 Hz, 0.75 Hz, 1.0 Hz, 2.0 Hz, 5 Hz, or 10 Hz. Pulsed flow can be provided by turning the motor on and off, and/or by providing a flow diverter that interrupts flow of the fluid.
While tanks have been referred to herein, jet mixing may be used in any type of vessel or container, including lagoons, pools, ponds and the like. If the container in which mixing takes place is an in-ground structure such as a lagoon, it may be lined. The container may be covered, e.g., if it is outdoors, or uncovered.
While hydrocarbon-containing feedstocks have been described herein, other feedstocks and mixtures of hydrocarbon-containing feedstocks with other feedstocks may be used. For example, some implementations may utilize mixtures of hydrocarbon-containing feedstocks with biomass feedstocks such as those disclosed in U.S. Provisional Application No. 61/218,832, filed Jun. 19, 2009, the full disclosure of which is incorporated by reference herein.
Accordingly, other embodiments are within the scope of the following claims. | Hydrocarbon-containing feedstocks are processed to produce useful intermediates or products, such as fuels. For example, systems are described that can process a petroleum-containing feedstock, such as oil sands, oil shale, tar sands, and other naturally-occurring and synthetic materials that include both hydrocarbon components and solid matter, to obtain a useful intermediate or product. | 1 |
[0001] This application is a continuation-in-part application of co-pending U.S. patent application Ser. No. 11/230,420 filed Sep. 19, 2005 which was a continuation-in-part of then co-pending U.S. patent application Ser. No. 11/165,295 filed Jun. 22, 2005 which was a continuation-in-part of then co-pending U.S. patent application Ser. No. 11/001,268 filed Nov. 30, 2004 which was a divisional of then co-pending U.S. Pat. No. 10/280,624 filed Oct. 25, 2002 which matured into U.S. Pat. No. 6,849,064.
FIELD OF THE INVENTION
[0002] The present invention relates to improvements in the field of minimal access lumbar posterior surgery and more particularly to instrumentation which allows for maximal access to the surgical field through the smallest possible incision. Greater access is allowed into the working field while enjoying the reduction of trauma and disturbance to surrounding tissues, which results in a reduced the time necessary to complete the operative procedure, increased safety of the procedure, and increased accuracy by providing an expanded working field.
BACKGROUND OF THE INVENTION
[0003] Microscopic Lumbar Diskectomy techniques were developed and championed by Dr. Robert Williams in the late 1970's and by Dr. John McCullough in the late 1980's and 1990's. For the first time since the advent of Lumbar Disc Surgery by Mixter and Barr in 1934 a method was introduced allowing Lumbar Disc Surgery to be performed through a small incision safely resulting in faster patient recovery and converting a two to five hospital stay procedure virtually to an outpatient procedure.
[0004] The special retractors developed by Drs. Williams and McCullough however were often difficult to maintain in optimum position and relied on the interspinous and supraspinatus ligaments for a counter fixation point severely stretching the structures. This stretching along with the effects of partial facectomy, diskectomy, removal of the ligamentum flavum and posterior longitudinal ligament contributed to the development of Post Diskectomy Instability. Taylor retractors were also used but were cumbersome, required larger incisions and often injured the facet joints.
[0005] Dr. William Foley in 1997 introduced a tubular system mated to an endoscope which he labeled a Minimal Endoscopic Diskectomy (MED) system. It featured sequentially dilating the Lumbar Paraspinous Muscles allowing a working channel to be advanced down to the level of operation through which nerve root decompression and Diskectomy Surgery could be performed with a small incision and less muscle trauma. Improvements were made by Dr. Foley in his second generation METRx system. However, there were several disadvantages to the MED and METRx systems.
[0006] In the MED and METRx systems, the cylindrical working channel considerably restricted visualization and passage of instruments. It also compromised the “angle of approach” necessary for safe usage of the operating instruments. This problem was proportionately aggravated with the long length of the tube. This compromised visualization contributed to the following problems, including nerve injury, dural tear, missed disc fragments, inadequate decompression of the lateral recess, increased epidural bleeding, difficulty controlling epidural bleeding, inadequate visualization of the neuroforamen, and inadequate decompression of neuroforamen.
[0007] The repetitive introduction of successively larger dilators caused skin abrasion with the potential for carrying superficial skin organisms down to the deeper tissue layers hypothetically increasing the risk of infection. The learning curve for operating in a two dimension endoscopic field proved to be arduous and contributed to the above complications.
[0008] The attempted use of the METRx system for more complex procedures such as fusion was further hazardous by inherent limitations.
[0009] Endius in September of 2000 then introduced a similar device which differed by having an expandable foot piece to allow greater coverage of the operative field. However, the enlarged foot piece was unwieldy and difficult to seat properly. Exposure of the angle of approach was also limited by having to operate through a proximal cylindrical tube with its limitations as described before. In comparison to the METRx system the working area was improved but access was again restricted by the smaller proximal cylinder.
[0010] Both systems offered endoscopic capability but many spine surgeons chose to use an operating microscope or loupes to maintain 3-Dimensional visualization rather than the depth impaired 2-Dimensional endoscopic presentation. Keeping debris off of the endoscopic lens has also proved to be a troubling challenge.
SUMMARY OF THE INVENTION
[0011] The system and method of the invention, hereinafter minimal incision maximal access system, includes a surgical operating system that allows for maximum desirable exposure along with maximum access to the operative field utilizing a minimum incision as small as the METRx and Endius systems. The minimal incision maximal access system disclosed offers advantages over the METRx and Endius systems in several respects. First, instead of multiple insertions of Dilating Tubes the Invention is a streamlined single entry device. This avoids repetitive skin surface entry. Second, the minimal incision maximal access system offers the capability to expand to optimum exposure size for the surgery utilizing hinged bi-hemispherical or oval Working Tubes applied over an introducer Obturator which is controllably dilated to slowly separate muscle tissue.
[0012] Third, the minimal incision maximal access system maximizes deeper end working and visualization area with maximum proximal access and work dimensions significantly greater than either the METRx or Endius devices and methods. Fourth, the minimal incision maximal access system provides expanded visual and working field to makes the operative procedure safer in application and shorten the surgeons's learning curve because it most closely approximates the open microdiskectomy techniques. Fifthly, the minimal incision maximal access system has a tapered ended Obturator which allows for tissue spread rather than muscle tissue tear and subsequent necrosis.
[0013] Sixth, the minimal incision maximal access system controls muscle oozing into the operative field which is controlled by simply opening the tubes further. This also thereby controls the bleeding by pressure to the surrounding tissues. Seventh, in contrast to the cylindrical tube based systems such as the METRx and Endius the minimal incision maximal access system offers a larger working area in proportion to the working depth. For the first time this allows for a minimal access technique to be applied to the large or obese patients. The enlarged footprint of the longer tubes in the minimal incision maximal access system is a major difference from any other minimal access system.
[0014] An eighth advantage of the minimal incision maximal access system is that ist expandable design allows for excellent exposure for more complex procedures such as fusion and instrumentation including TLIF, PLIF, and TFIF (Transfacet Interbody Fusion), as well as allowing application for anterolateral lumbar disc surgery. The minimal incision maximal access system can also be used for cervical surgery posteriorly (foraminotomy, lateral mass instrumented fusion) as well as anterior cervical diskectomy and fusion. The minimal incision maximal access system can also be used for anterior lumbar interbody fusion be it retroperitoneal, transperitoneal or laparoscopic.
[0015] A ninth advantage of the minimal incision maximal access system is that the medial oval cutout of the retractors, or sleeve forming the working tube, allows more central docking on the spine which is problematic for other devices. A medialized docking provides access for easier and better and safer dural retraction to address midline pathology. A tenth advantage is had by including an anti-reflective inner surface of the retractor sleeves which eliminates unwanted glare.
[0016] An eleventh advantage of the minimal incision maximal access system includes the slanted and contoured distal end of the retractor sleeve which allows minimal resistance for entry and advancement to the docking site. A twelfth advantage minimal incision maximal access system is the provision of a variety of retractor tips specific for different surgical procedures.
[0017] A thirteenth advantage of the minimal incision maximal access system is the provision of oval retractor sleeves for larger access requirements such as pedicle to pedicle exposure and especially in the case where pedicle screw instrumentation is to be applied. This minimizes unnecessary muscle spread by providing a smaller waist profile than a circular system. A fourteenth advantage of the minimal incision maximal access system is that the larger retractor sleeve also features one or two “skirts” to cover the lateral aperture created by the spread of the two retractor sleeves when opened. This prevents soft tissue and muscle ingress into the working cone. The skirts are attached to the working tube either at the hinge or on one of the two halves of the sleeve.
[0018] A fifteenth advantage of the minimal incision maximal access system is the provision of a modular design in which the retractor sleeves can be quickly removed, changed and reapplied. In this version the proximal port can also be modular and changeable to fit the needs of a specific surgical procedure. A sixteenth advantage of the minimal incision maximal access system is that the retractor sleeves can be made out of metal, ceramic or plastic, can be opaque or translucent, and can have tips of different shapes for different applications. A seventeenth advantage is the provision of snap lock connections of the major parts of the Invention provides for easy assembly and disengagement for cleaning and sterilization purposes.
[0019] Further, the Obturator is cannulated for carrying a central Guide Pin Passage. It has a Handle component which remains superficial to the skin. The obturator houses an internal hinge device which allows for spread of the two obturator tips.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The invention, its configuration, construction, and operation will be best further described in the following detailed description, taken in conjunction with the accompanying drawings in which:
[0021] FIG. 1 is a perspective view of a working tube with an angled upper section and shown in position with respect to an obturator insertable into and workable within the working tube;
[0022] FIG. 2 is a perspective assembled view illustrating the relative positions of the obturator and working tube;
[0023] FIG. 3 is a perspective assembled view illustrates the position of the obturator after it has been inserted into the working tube;
[0024] FIG. 4 is a view taken along line 4 - 4 of FIG. 2 and looking into the working tube of FIG. 1 ;
[0025] FIG. 5 is a sectional view taken along line 5 - 5 of FIG. 2 and looking into the hinge of working tube of FIG. 1 , illustrating its hinge connections;
[0026] FIG. 6 is an side end view of the working tube of FIGS. 1-5 and illustrating predominantly one of the rigidly connected halves of the invention;
[0027] FIG. 7 is a side sectional view taken along line 7 - 7 of FIG. 6 and showing the internal bearing pivot;
[0028] FIG. 8 is a side sectional view taken along line 8 8 of FIG. 5 and illustrating a option for external bevel for the working tube;
[0029] FIG. 9 is a side view of the working tube of FIGS. 1-8 shown with the lower portions in parallel alignment and the upper portions angled with respect to each other;
[0030] FIG. 10 is a side view of the working tube as seem in FIG. 9 and shown with the lower portions in an angled relationship and the upper portions in a closer angled relationship with respect to each other;
[0031] FIG. 11 is a side view of the working tube as seen in FIGS. 9 and 10 and shown with the lower portions in a maximally angled relationship and the upper portions in parallel alignment signaling maximal spread of the lower portions in bringing the upper portions into parallel alignment;
[0032] FIG. 12 is a side view of the obturator of FIG. 1 and seen in an assembled view and emphasizing a through bore seen in dashed line format;
[0033] FIG. 13 is a side view of the obturator of FIG. 11 as seen in an assembled view but turned ninety degrees about its axis and emphasizing the through bore;
[0034] FIG. 14 shows a side view of the obturator 33 of FIG. 13 with the spreading legs in an angled apart relationship;
[0035] FIG. 15 is a sectional view taken along line 14 - 14 of FIG. 12 and gives a sectional view from the same perspective seen in FIG. 14 ;
[0036] FIG. 16 is a view of the obturator similar to that seen in FIG. 15 , but turned ninety degrees along its axis and illustrates the wedge as having a narrower dimension to lend internal stability;
[0037] FIG. 17 is a closeup view of the external hinge assembly seen in FIG. 1 and illustrates the optional use of a plug to cover the exposed side of a circular protrusion;
[0038] FIG. 18 is a view taken along line 18 - 18 of FIG. 11 and illustrates the use of an optional skirt having flexible members which spread from an initial curled position to a straightened position to better isolate the surgical field;
[0039] FIG. 19 is a view of the lower tube hemicylindrical portions 65 and 69 in a close relationship illustrating the manner in which the skirts sections within their accommodation slots areas;
[0040] FIG. 20 is a cross sectional view of the a patient and spine and facilitates illustration of the general sequence of steps taken for many procedures utilizing the minimal incision maximal access system disclosed;
[0041] FIG. 21 illustrates a fascial incisor over fitting a guide pin and further inserted to cut through external and internal tissue;
[0042] FIG. 22 illustrates the assembled Working Tube—Obturator being inserted into the area previously occupied by the fascial incisor and advanced to the operative level lamina;
[0043] FIG. 23 illustrates the obturator 33 being actuated to a spread orientation to which automatically actuates the working tube to a spread orientation;
[0044] FIG. 24 is a view of the working tube 35 is in place and supported, held or stabilized in the field of view by a telescopy support arm and engagement, the opposite end of the stabilizing structure attached to the operating table;
[0045] FIG. 25 illustrates further details of the support arm seen in FIG. 24 , especially the use of a ball joint;
[0046] FIG. 26 illustrates a side view of the assembly seen in FIG. 25 is seen with an adjustable clamp operable to hold the working tube open at any position;
[0047] FIG. 27 is a top view looking down upon the adjustable clamp seen in FIGS. 25-26 and shows the orientation of the working tube and adjustable clamp in fully closed position;
[0048] FIG. 28 shows a variation on the obturator seen previously in FIG. 1 and illustrates the use of handles which are brought together;
[0049] FIG. 29 illustrates a further variation on the obturator seen previously in FIG. 1 and illustrates the use of a central ball nut;
[0050] FIG. 30 is a sectional view taken along line 30 - 30 of FIG. 29 and illustrates the use of a central support block to support the central threaded surface;
[0051] FIG. 31 is a top view of a thin, inset hinge utilizable with any of the obturators herein, but particularly obturators of FIGS. 1 and 29 ;
[0052] FIG. 32 is a sectional view of the obturator of FIG. 1 within the working tube of FIG. 1 with the wedge 51 seen at the bottom of an internal wedge conforming space;
[0053] FIG. 33 illustrates the obturator seen in FIG. 32 as returned to its collapsed state.
[0054] FIG. 34 illustrates a top and schematic view of the use of a remote power control to provide instant control of the working tube using an adjustable restriction on the upper angled hemicylindrical portions of the working tube;
[0055] FIG. 35 is a view taken along line 35 - 35 of FIG. 34 and illustrating the method of attachment of the cable or band constriction;
[0056] FIG. 36 is a mechanically operated version of the nut and bolt constriction band seen in FIG. 25 ;
[0057] FIG. 37 is an isolated view of two hemicylindrical tube sections shown joined in a tubular relationship and indicating at least a pair of pivot axes on each hemicylindrical tube section;
[0058] FIG. 38 is an isolated view of two hemicylindrical tube sections as seen in FIG. 38 which are angularly displaced apart about a shared first pivot axis on each of the hemicylindrical tube sections;
[0059] FIG. 39 is an isolated view of two hemicylindrical tube sections as seen in FIGS. 38 and 39 which are angularly displaced apart about a shared second pivot axis on each of the hemicylindrical tube sections;
[0060] FIG. 40 is a plan view of a given width supplemental side shield having a width of approximately the separation of the hemicylindrical tube sections as seen in FIG. 39 ;
[0061] FIG. 41 is a top view of the supplemental side shield of FIG. 40 ;
[0062] FIG. 42 is a pivoting thread support system in which a pair of opposing flank threaded members operate a pivoting support and are connected by a gear mechanism shown in exaggerated format to give single knob separation control;
[0063] FIG. 43 illustrates a surrounding frame system utilized to provide and enable pivoting and translation;
[0064] FIG. 44 illustrates a view looking down into the structure of FIG. 43 shows the overall orientation and further illustrates an optional securing tang;
[0065] FIG. 45 illustrates a simplified control scheme in which simplicity is emphasized over controllability with less moving parts and expense;
[0066] FIG. 46 illustrates a further embodiment of a manipulative structure which works well with the structure of FIG. 45 ;
[0067] FIG. 47 illustrates another possible realization which combines the control mechanisms of selected portions of FIGS. 37-46 , combined with other possible options;
[0068] FIG. 48 illustrates a side view of the side shield seen in FIG. 47 ;
[0069] FIG. 49 illustrates one possible configuration for a variable depth guide which is utilizable with any of the devices seen in FIGS. 37-46 or any other tubular, minimally invasive system;
[0070] FIG. 50 is a vertical plan view of an expandable frame system which uses detents to set the frame size and which uses an angular distribution system;
[0071] FIG. 51 is a top view of the system of FIG. 51 in an expanded position;
[0072] FIG. 52 is a side view of the system of FIGS. 50-52 ;
[0073] FIG. 53 illustrates a top view double pivot hinge fitting and illustrating the gear surfaces;
[0074] FIG. 54 illustrates the action of the pivot hinge which produces an even angular deflection;
[0075] FIG. 55 illustrates a top view of a bookwalter device mounted atop a central hinge box seen in FIG. 53 ;
[0076] FIG. 56 is a top view of a retractor system employing many of the components seen in FIGS. 50-52 for applying force from a distance;
[0077] FIG. 57 is a top view of a hemicylindrical retractor tube extension;
[0078] FIG. 58 is a side sectional view of the hemicylindrical retractor tube extension of FIG. 57 attached to the hemicylindrical tube seen in FIG. 52 ;
[0079] FIG. 59 is a view looking down into the inside of the hemicylindrical retractor tube extension of FIGS. 57 and 58 ;
[0080] FIG. 60 is a view looking down onto the outside of the hemicylindrical retractor tube extension of FIGS. 57-59 ;
[0081] FIG. 61 is an exploded view of a further embodiment of a frame retractor system utilizing a base frame and raised tube manipulator;
[0082] FIG. 62 is a perspective view of the frame retractor system seen in FIG. 61 ;
[0083] FIG. 63 is a perspective view of the frame retractor system from the same perspective as seen in FIG. 61 and illustrated as being fitted with a fiber optic illuminator;
[0084] FIG. 64 is a top view of the frame retractor system seen in FIGS. 61-63 ;
[0085] FIG. 65 is a bottom view of the frame retractor system seen in FIGS. 61-64 ;
[0086] FIG. 66 is a side view of the frame retractor system seen in FIGS. 61-65 ;
[0087] FIG. 67 is a perspective view of a wire retractor utilizable with the frame retractor system of FIGS. 61-67 ;
[0088] FIG. 68 is an isolated view of the ends of the wire retractor shown in an opening pattern;
[0089] FIG. 69 is an isolated view of the ends of the wire retractor shown superimposed in a crossing pattern to reduce the profile for entry into the frame retractor system of FIGS. 61-66 ;
[0090] FIG. 70 is a side view of the frame retractor system seen in FIGS. 61-63 , and illustrating portions of an optional wire guide retractor;
[0091] FIG. 71 illustrates the frame retractor system and wire retractor shown with respect to tissue; and
[0092] FIG. 72 illustrates the wire retractor being opened to an open position within the frame retractor system and within the tissue.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0093] The description and operation of the minimal incision maximal access system will be best described with reference to FIG. 1 and identifying a general system 31 . System 31 includes an obturator 33 and a working tube 35 . The orientation of the obturator 33 is in a slightly displaced from a position of alignment with the working tube 35 for entry into working tube 35 and to provide the initial carefully controlled force for spreading the working tube 35 , as will be shown.
[0094] Obturator includes an upper control housing 37 and a pair of spreading legs 39 and 41 . The spreading legs 39 and 41 are seen as coming together to form a conical tip and thus have hemi-conical end portions. The spreading legs 39 and 41 over fit the attachment leg portions 43 and 45 , respectively. At the top of the upper control housing 37 a boss 47 surrounds and supports the extension of a control shaft 49 . a knurled thumb knob 50 sits atop the control shaft 49 to facilitate controlled turning of the control shaft 49 to control the degree of spreading of the spreading legs 39 and 41 . Thus spreading can be controlled independently of pressure applied along the length of the obturator 33 .
[0095] Below the upper control housing 37 is the bottom of the control shaft 49 which operates against a wedge 51 . The wedge 51 operates within a pair of opposing slots 52 in an upper portion 53 of the overfit attachment leg portions 43 and 45 . The lower ends of the overfit attachment leg portions 43 and 45 include insertion tangs 55 which fit within insertion slots 57 of the spreading legs 39 and 41 . The overfit attachment leg portions 43 and 45 are pivotally attached to the upper control housing 37 internally by pivot blocks 59 which fit within access apertures 60 .
[0096] The working tube 35 has a first lower extending connection tang 61 and a second lower extending connection tang 63 . First lower extending connection tang 61 connects into a slot 64 of a lower tube hemicylindrical portion 65 . The first lower extending connection tang 61 is fixed to an upper angled hemicylindrical portion 67 . The second lower extending connection tang 63 connects into a slot 68 of a lower tube hemicylindrical portion 69 . Second lower extending connection tang 61 is fixed to and an upper angled hemicylindrical portion 71 . The upper angled hemicylindrical portion 67 has a reinforced wear plate 73 for applying upper pressure and force on the upper angled hemicylindrical portions 67 and 71 toward each other to cause the first and second lower extending connection tangs 61 & 63 and their connected lower tube hemicylindrical portions 65 and 69 to be urged away from each other.
[0097] At the side of the working tube 35 at the transition between the upper angled hemicylindrical portions 67 and 71 and a point just above the first and second lower extending connection tangs 61 & 63 is an external hinge assembly 77 . Hinge assembly 77 may include an optional first guide plate 79 and first circular protrusion 81 attached to upper angled hemicylindrical portions 67 , and a first slotted plate 83 positioned adjacent to first guide plate 79 and having a slot partially surrounding the circular protrusion 81 .
[0098] Upper angled hemicylindrical portion 71 has a pair of spaced apart facing surfaces facing a matching pair of facing surfaces of the upper angled hemicylindrical portion 67 , of which a dividing line 85 is seen. Upper angled hemicylindrical portions 67 and 71 are be brought together to cause the first and second lower extending connection tangs 61 & 63 and their connected lower tube hemicylindrical portions 65 and 69 to spread apart.
[0099] In the View of FIG. 1 , the first and second lower extending connection tangs 61 & 63 are shown in a spread apart relationship. a locking pin 87 is seen which can be used to engage angularly spaced apart apertures in the circular protrusion 81 to provide a detent action to hold the working tube 35 in various degrees of spread. Also seen is a slight exterior bevel 89 on the lower tube hemicylindrical portions 65 and 69 .
[0100] Note the angled separation of the upper angled hemicylindrical portions 67 and 71 and exposing opposing surfaces 91 . The angle of the opposing surfaces 91 equals the angle of spread of the first and second lower extending connection tangs 61 & 63 .
[0101] Referring to FIG. 2 , a perspective assembled view illustrates the relative positions of the obturator 33 and working tube 35 in a position for the obturator 33 to be inserted into the working tube 35 and before any spreading takes place.
[0102] Referring to FIG. 3 , a perspective assembled view illustrates the position of the obturator 33 after it has been inserted into the working tube 35 and again before any spreading takes place. Note that the pivot axes of the first and second lower extending connection tangs 61 & 63 are on par with the pivot axes of the insertion tangs 55 . The tip of the obturator 33 extends slightly beyond the bottom most part of the working tube 35 so that the completed assembly can be smoothly urged past muscle and other tissue.
[0103] Referring to FIG. 4 , a view taken along line 4 - 4 of FIG. 1 is a view looking down into the working tube 35 . Other features seen include a wear plate 93 located on the upper angled hemicylindrical portion 71 . In both of the wear plates 73 and 93 a universal port 94 is provided as a bore for insertion of a tool or lever to assist in bringing the upper angled hemicylindrical portions 67 and 71 into a tubular relationship. Further, an identical hinge assembly 77 on the side opposite that seen in FIG. 1 is shown with the same numbering as the components which were seen in FIG. 1 .
[0104] Also seen are a pair of opposing surfaces 95 on upper angled hemicylindrical portion 71 and a pair of opposing surfaces 97 on upper angled hemicylindrical portion 67 . Also seen is a central working aperture 99 .
[0105] Referring to FIG. 5 , a view taken along line 5 - 5 of FIG. 1 is a sectional view looking down into the working tube 35 . The connectivity of the structures seen in FIG. 4 are emphasized including the connection of circular protrusion 81 to the upper angled hemicylindrical portion 71 , and the connection of first slotted plate 83 to upper angled hemicylindrical portion 67 , and which is indicated by the matching section lines Further, an identical hinge assembly 77 on the side opposite that seen in FIG. 1 is shown with the same numbering as the components which were seen in FIG. 1 .
[0106] Referring to FIG. 6 , a view of one end of the working tube 35 illustrates predominantly the second angled half portion 63 . Elements seen in FIGS. 1 and 2 are made more clear in FIG. 3 .
[0107] Referring to FIG. 7 , a side sectional view taken along line 7 - 7 of FIG. 6 and shows the internal bearing pivot consisting of a slightly greater than hemispherical side bump projection 101 located on upper angled hemicylindrical portion 71 , and a slightly less than hemispherical side circular groove 103 located on upper angled hemicylindrical portion 67 . Also seen is the interconnect slots 64 and 68 as well as the first and second lower extending connection tangs 61 and 63 . In the showing of FIG. 7 an external bevel 105 is utilized Referring to FIG. 8 , a side semi-sectional view taken along line 8 - 8 of FIG. 5 illustrates the integral connectivity of circular protrusion 81 with the upper angled hemicylindrical portion 71 . Seen for the first time in isolation are a pair of pin apertures 107 for engaging the locking pin 87 .
[0108] Referring to FIG. 9 , an illustration of a side plan view and in which the lower tube hemicylindrical portions 65 and 69 are in matching straight alignment and forming a lower tube shape, while the upper angled hemicylindrical portions 67 and 71 are angled apart.
[0109] Referring to FIG. 10 , a midpoint of movement is illustrates wherein the lower tube hemicylindrical portions 65 and 69 have begun to move apart widening the lower tube shape previously formed into an angled apart opposing hemicylindrical shape, while the upper angled hemicylindrical portions 67 and 71 are brought closer together to have a closer though angled apart an angled apart opposing hemicylindrical shape.
[0110] Referring to FIG. 11 , a completed movement, with respect to the view of FIG. 4 illustrates a state where the lower tube hemicylindrical portions 65 and 69 have moved apart to their maximum extent into a maximally angled apart opposing hemicylindrical shape, while the upper angled hemicylindrical portions 67 and 71 are brought completely together to form an upper tube shape. It is the position of FIG. 6 which is the ideal working position once the lower tube hemicylindrical portions 65 and 69 are within the body, and provides an expanded working field at the base of the working tube 35 . Surgical work is ideally performed through the upper, abbreviated axial length tube shape formed by the upper angled hemicylindrical portions 67 and 71 .
[0111] Referring to FIG. 12 , a side view of the obturator 33 of FIG. 1 is seen in an assembled view and emphasizing in dashed line format a through bore 111 which extends though the obturator 33 from the knurled knob 50 through to the tip of the pair of spreading legs 39 and 41 .
[0112] Referring to FIG. 13 , a side view of the obturator 33 of FIG. 11 is seen in an assembled view but turned ninety degrees about its axis, and agin emphasizing in dashed line format the through bore 111 which extends though the obturator 33 from the knurled knob 50 through to the tip of the pair of spreading legs 39 and 41 . It is from this position that further actuation will be illustrated.
[0113] Referring to FIG. 14 , a side view of the obturator 33 of FIG. 13 is seen but with the spreading legs 39 and 41 in an angled apart relationship. An optional support 112 is supported by the upper control housing 37 to enable independent support and location of the obturator 33 should it be needed. Once the knurled knob 50 is turned, the wedge 51 seen in FIG. 1 is driven downward causing the spreading of the spreading legs 39 and 41 .
[0114] Referring to FIG. 15 , a sectional view taken along line 14 - 14 of FIG. 12 gives a sectional view from the same perspective seen in FIG. 14 . Pivot blocks 59 are seen as having pivot bores 113 which enable the upper portions 53 to pivot with respect to the upper control housing 37 and which enable the downward movement of the wedge 51 to translate into a spreading of the spreading legs 39 and 41 .
[0115] As can be seen, the knob 50 and control shaft 49 and the wedge 51 have the through bore 111 . In the configuration shown, the control shaft 49 includes a threaded portion 113 which engaged an internally threaded portion 115 of an internal bore 117 of the upper control housing 37 . The boss 47 is shown to be part of a larger insert fitting within a larger fitted bore 119 within the upper control housing 37 . This configuration pushes the wedge 51 downwardly against an internal wedge conforming space 123 to cause the insertion tangs 55 and upper portions 53 to spread apart. The wedge conforming space 123 need not be completely wedge shaped itself, but should ideally have a surface which continuously and evenly in terms of area engages the wedge 51 to give even control. Further, the wedge 51 can be configured to be rotatable with or independently rotationally stable with respect to the control shaft 49 . As can be seen, the through bore 111 continues below the internal wedge conforming space 123 as a pair of hemicylindrical surfaces 125 in the upper portion 53 , as well as a pair of hemicylindrical surfaces 127 in the pair of spreading legs 39 and 41 .
[0116] Referring to FIG. 16 a view of obturator 33 similar to that of FIG. 15 , but turned ninety degrees along its axis is seen. In this view, the wedge 51 is seen as having a narrower dimension to lend internal stability by narrowing the bearing area of the wedge 51 action in opening the pair of spreading legs 39 and 41 .
[0117] Referring to FIG. 17 , a closeup view of the external hinge assembly 77 seen in FIG. 1 illustrates the optional use of a plug 131 to cover the exposed side of the circular protrusion 81 .
[0118] Referring to FIG. 18 , a view taken along line 18 - 18 of FIG. 11 illustrates a view which facilitates the showing of an optional skirt, including a skirt section 133 welded or otherwise attached to lower tube hemicylindrical portion 65 , and a skirt section 133 welded or otherwise attached to lower tube hemicylindrical portion 69 . The skirts sections 133 and 135 are made of thin flexible metal and interfit within a pair of accommodation slots 137 and 139 , respectively.
[0119] Referring to FIG. 19 , a view of the lower tube hemicylindrical portions 65 and 69 in a close relationship illustrates the manner in which the skirts sections 133 and 135 fit within the accommodation slots 137 and 139 when the lower tube hemicylindrical portions 65 and 69 are brought together to a circular configuration.
[0120] Referring to FIG. 20 , a cross sectional view of the a patient 151 spine 153 is shown for illustration of the general sequence of steps taken for any procedure utilizing the minimal incision maximal access system 31 . There are several procedures utilizable with the minimal incision maximal access system 31 . Only a first procedure will be discussed using illustrative figures. Other procedures will be discussed after minor variations on the minimal incision maximal access system 31 are given below.
[0000] Procedure I: Diskectomy and Nerve Decompression
[0121] The patient 151 is placed prone on radiolucent operating table such as a Jackson Table. The patient 151 is then prepared and draped. The operative area is prepared and localized and an imaging device is prepared. A guide pin 155 is insert through the patient's skin 157 , preferably under fluoroscopic guidance. In the alternative and or in combination, the patient 151 skin can be incised with a scalpel. Other features in FIG. 20 include the dural sac 159 , and ruptured intervertebral disc 161 .
[0122] Referring to FIG. 21 , a fascial incisor 169 over fits the guide pin 155 and is further inserted to cut through external and internal tissue. The fascial incisor 169 is then removed while the guide pin 155 is left in place. Next, using the obturator 33 , the surgeon clears the multifidus attachment with wig-wag motion of the obturator 33 tip end. Next the obturator 33 is actuated to gently spread the multifidus muscle, and then closed.
[0123] Referring to FIG. 22 , next the assembled Working Tube 35 —Obturator 33 is inserted into the area previously occupied by the fascial incisor 169 and advanced to the operative level lamina and remove the obturator 33 . As an alternative, and upon having difficulty, the obturator 33 could be initially inserted, followed by an overfit of the working tube 35 . In another possibility, a smaller size of obturator 33 and working tube 35 or combination thereof could be initially utilized, followed by larger sizes of the same obturator 33 and working tube 35 . The assembled Working Tube 35 —Obturator 33 in place is shown in FIG. 22 with the working ends very near the spine.
[0124] Referring to FIG. 23 , the obturator 33 is actuated to a spread orientation, which automatically actuates the working tube 35 to a spread orientation. Spread is had to the desired exposure size. The obturator 33 is thin actuated to a closed or non-spreading position. The obturator and working tube is then again advanced to dock on the spine. The working tube 35 is then fixed to assume an open position either by utilization of the locking pin 87 or other fixation device to cause the working tube 35 to remain open. Then, once the working tube 35 is locked into an open position, the obturator 33 is actuated to a closed or non-spread position and gently removed from the working tube 35 .
[0125] Referring to FIG. 24 , the working tube 35 is in place. The working tube 35 may be secured by structure ultimately attached to an operating table. The working tube 35 may be held or stabilized in the field of view by a support 181 which may have an engagement sleeve 183 which fits onto the working tube. As can be seen, the operative field adjacent the spine area is expended even though the incision area is limited. The deeper a given size of working tube 35 is inserted, the smaller its entrance area. After the working tube 35 is stabilized, the surgeon will typically clear the remaining multifidus remnant at the working level and then set up and insert an endoscope or use operating microscope or loupes. The surgeon is now ready to proceed with laminotomy.
[0126] Referring to FIG. 25 , further detail on the support 181 and engagement sleeve 183 is shown. A base support 185 may support a ball joint 187 , which may in turn support the support 181 . The support 181 is shown as supporting a variation on the engagement sleeve 183 as a pivot point support engagement end 188 having arm supports 189 and 191 . The arm supports 189 and 191 engage the external pivot structure on the working tube 35 which was shown, for example, in FIG. 1 to be the external hinge assembly 77 .
[0127] As a further possibility, the upper angled hemicylindrical portions 67 and 71 are shown as being engaged about their outer periphery by an adjustable clamp 195 . Adjustable clamp 195 includes a band 197 encircling the upper angled hemicylindrical portions 67 and 71 . The ends of band 197 form a pair of opposing plates 199 and are engaged by a nut 201 and bolt 203 assembly.
[0128] Referring to FIG. 26 , a side view of the assembly seen in FIG. 25 is seen with the adjustable clamp 195 operable to hold the working tube 35 open at any position. Referring to FIG. 27 , a top view looking down upon the adjustable clamp 195 seen in FIGS. 25-27 shows the orientation of the working tube 35 and adjustable clamp 195 in fully closed position. When used in conjunction with the adjustable clamp 195 , the Reinforced wear plates 73 and 93 are eliminated so as to provide a smooth interface against the exterior of the upper angled hemicylindrical portions 67 and 71 .
[0129] Referring to FIG. 28 , a variation on the obturator 33 is seen. An obturator 215 has handles 217 and 219 which operate about a pivot point 221 . A working tube 222 is somewhat simplified but is equivalent to the working tube 35 and is shown as including upper angled hemicylindrical portions 67 and 71 . Handle 219 has a ratchet member 223 extending from it and a latch 227 pivotally connected about pivot point 229 to handle 217 .
[0130] Referring to FIG. 29 , a variation on obturator 33 is seen as an obturator 241 having an upper housing 243 , control shaft 245 having a threaded section 247 and operating through a ball nut 249 . A wedge 251 is extendable down through an operation space made up of a half space 253 in a leg 255 and a half space 257 in a leg 259 . Hinge structures 261 are shown attaching the legs 255 and 259 to the upper housing 243 . A through bore 111 is also seen as extending from the knob 261 through to the bottom of the wedge 251 . An access groove 263 is carried by the leg 259 while An access groove 263 is carried by the leg 259 while an access groove 265 is carried by the leg 255 .
[0131] Referring to FIG. 30 , a sectional view taken along line 30 - 30 of FIG. 29 illustrates the use of a central support block 271 to support the a central threaded surface 273 and the legs 255 and 259 .
[0132] Referring to FIG. 31 , a view of a thin, inset hinge 281 utilizable with any of the obturators, but particularly obturators 33 and 241 , is shown. In the case of obturator 33 , by way of example, upper portions 53 accommodate control shaft 49 with its through bore 111 . Inset hinge 281 may be have an inset 283 and secured with machine screws 285 . Inset hinge 281 may be made of a “living hinge” material such as a hard plastic, or it can have its operations base upon control bending of a pre-specified length of steel, since the angle of bend is slight. The connection between the upper portions 53 and the upper control housing 37 may be by any sort of interlocking mechanism, the aforementioned pivot blocks 59 or other mechanism.
[0133] Referring to FIG. 32 , a sectional view of the obturator 33 within the working tube 35 is seen. The wedge 51 is seen at the bottom of the internal wedge conforming space 123 . Once the spreading of the working tube 35 is accomplished the working tube 35 is kept open by any of the methods disclosed herein. Also seen is a pivot ball 116 to allow the control shaft 49 to turn with respect to the wedge. The pivot ball will continue to support a central aperture bore 111 . Once the working tube 35 is stabilized in its open position, the obturator 33 is returned to its collapsed state as is shown in FIG. 33 .
[0134] Provision of electro-mechanical power to the operation of the working tube 35 can provide a surgeon an additional degree of instant control. Referring to FIG. 34 , a top and schematic view of the use of a remote power control to provide instant control of the working tube 25 , similar to the view seen in FIG. 25 illustrates the use of a remote annular control cable 301 using an internal cable 303 which is closely attached using a guide 305 and which circles the upper angled hemicylindrical portion 67 and 71 , terminating at an end fitting 307 .
[0135] The annular cable 301 is controlled by a BATTERY MOTOR BOX 311 having a forward and reverse switch 313 (with off or non actuation being the middle position). This enables the surgeon to expand the surgical field as needed and to collapse the surgical field to focus on certain working areas. BATTERY MOTOR BOX 311 is configured with gears to cause the cable 303 to forcibly move axially within the annular cable 301 to transmit mechanical power to the working tube 35 .
[0136] Referring to FIG. 35 , a view taken along line 35 - 35 of FIG. 34 illustrates how the cable 303 is held in place and a closeup of the end termination 307 .
[0137] Referring to FIG. 36 , a mechanically operated version of the nut 201 and bolt 203 constriction band seen in FIG. 25 . The mechanical power linkage can be provided remotely as by a rotating annular cable, but the basic mechanical setup shown illustrates the mechanical principles. On the bolt 203 , a gear head 325 is placed, either by attachment or by the provision of a threaded member and gear head made together. A second gear head 327 is utilized to show the possibility of providing a right angle power take-off in the event that the power connection interferes with the area around the surgical field. A shaft 329 extends from a BATTERY MOTOR BOX 331 . The BATTERY MOTOR BOX 331 has a forward and reverse switch 333 ,(with off or non actuation being the middle position). Shaft 329 could be flexible and connected directly into axial alignment with the threaded member of bolt 201 or an integrally formed threaded member.
Advantages Over Existing Surgical Techniques
[0138] In terms of general advantages, there are differences between the minimal incision maximal access system 31 , and its components as described in all of the drawings herein (but which will be referred throughout herein simply as the minimal incision maximal access system 31 , or simply system 31 ) and other devices and procedures.
1. With regard to the Traditional microdiskectomy technique, the minimal incision maximal access system 31 allows for at least the same, if not better visualization access of the operative field. System 31 offers the same 3-Dimensional work ability or, if preferred, an endoscope can be utilized. System 31 minimizes muscle injury with spread versus extensive cautery dissection. System 31 has clear advantage on the challenging obese and very large patient where the traditional microdiskectomy technique is almost impossible to be applied. 2. With regard to open pedicle screw insertion procedures, system 31 offers muscle approach minimizing muscle devascularization and denervation. The traditional approach had required at least one level proximal and one level distal additional exposure causing extensive muscle injury often leading to “fibrotic” muscle changes resulting in chronic painful and stiff lower back syndrome. System 31 offers the most direct approach to the pedicle entry point selecting the avascular plane between the longissimus and multifidus muscles. 3. With regard to the Sextant Procedure, system 31 offers clear advantage over the Sextant procedure. First, the system 31 offers a procedure which is not a blind pedicle screw technique. System 31 can be applied to larger and more obese patients in which the Sextant procedure cannot be utilized. In this procedure using system 31 oosterolateral fusion can be performed along with insertion of the pedicle screws. The sextant procedure is strictly a tension band stabilization.
[0142] In general, the components of the minimal incision maximal access system 31 are very simple the hemispherical shapes used for the working tube can be round or oval. A keying system can be had to align the obturator 33 to the working tube 35 . In the case of an oval system, the alignment would be automatic.
[0143] The minimal incision maximal access system 31 is a modular system with interchangeable parts for both the working tube 35 and the obturator 33 . The guide Pin 155 is of simple construction, as is the fascial incisor 169 . The working tube 35 has a limited number of basic parts, and can be made in the simple, two main piece version of FIG. 28 , or the multi-piece version of FIG. 1 , which enables retractor-sleeve substitution. A hinge and stabilization mechanism completes the simplified construction.
[0144] The obturator 33 is also of simple construction, with upper control housing 37 , pair of spreading legs 39 and 41 , and an internal hinge, whether the pivot blocks 59 or hinge 281 and its ability to support a control shaft 49 having a bore 111 for a guide pin 155 . Guide pin 155 may preferably have a size of from about 0.3 mm to 0.40 mm diameter and 30 cm to 40 cm in length. The fascial incisor may preferably be cannulated for usage with the guide pin 155 and have a width of about 2 mm more than the associated retractor. The overall cutting head length of about 1.2 cm has a shape as indicated in the Figures and has a thickness slightly larger than that of the guide pin 155 .
[0145] The working tube 35 can have several variations and added details including the simplest shapes as dictated by intended usage. Working tube 35 can have a simple fluted hemi-tube shape or a Slanted box shape. Further, the possibility of a fluted oval shape is dictated when the approach is more angular. The working tube 35 can have an attachment for an endoscope. Working tube 35 can also have a non-symmetric appearance as by having longitudinal cross sectional shape with half of its shape being rounded and one half of its shape being rectangular or box shaped. This could also give rise to a similarly shaped obturator 33 . The working tube 35 should have an anti-reflective inner coating and may be of modular construction.
[0146] The preferred lower dimensions for the lower tube hemicylindrical portions 65 and 69 include an overall shape which is semi tubular round or oval and having a width of from about 1.6-3.0 cm and a length of from about 4.0-18 cm. Hemicylindrical portions 65 and 69 may have custom cut outs depending upon planned application.
[0147] The hinge assembly 77 may have male-female post or male-female dial lock design, as well as a hinge housing and a bias (by spring or other mechanism) to keep angular displaceable portions of the working tube 35 closed. a “universal” port provides a point of attachment of an endoscopic or stabilizer bar.
[0148] The obturator 33 may be any controlled opening device including a circular band or cable, force Plates, or a device attached to hinge assembly 77 or other hinge assembly.
[0149] All sleeve attachments including the attachable legs 39 and 41 , as well as the lower tube hemicylindrical portions 65 and 69 should be of the friction grip type or snap and lock type or other suitable connection method or structure.
[0150] Obturator 215 may have squeeze grip scissor style handles 219 and 217 and a controlled dilator. It may utilize an enclosed design with a handle cover having a no-slip surface. It may be attached to the hinge housing of the working tube or separate hinge housing. In fact, it may be of a design to be held in place solely by the working tube 35 . Ideally a cavity will be provided through the center axis to contain the shaft for the dilator mechanism if applicable.
[0151] The central bore 111 of the obturator 33 may have a diameter of from about 5-10 mm, depending upon the size of the obturator 33 utilized. Obturator 33 should be provided in various widths and length to match working tube. The working tips of the spreading legs 39 and 41 may be changeable according to surgical procedures as described in the operative procedures herein. It may have an inner chamber, or internal wedge conforming space 123 slanted in shape wider proximal and more narrow distal to accommodate the wedge 51 . The internal wedge conforming space 123 can be enclosed with expanding, contracting sleeve.
Other Procedures
[0152] Many other procedures can be facilitated with the use of the inventive minimal incision maximal access system 31 and methods practiced therewith. Procedure I, a diskectomy and nerve decompression procedure was described above with reference to the Figures. Other procedures are as follows:
[0000] Procedure II: Facet Fusion
[0153] 1. Patient prone on Jackson Table with normal lordosis preserved. This can be increased by placing additional thigh and chest support to increase lumbar lordosis.
[0154] 2. Insert percutaneous special guide pin perpendicular to the floor at a point 1 cm caudal to the Alar-Superior facet notch.
[0155] 3. Apply a flag guide to a first guide pin 155 #1.
[0156] 4. Measure skin to bone depth from the scale on guide pin 155 #1.
[0157] 5. Slide drill guide mechanism on the flag guide to match the skin bone distance.
[0158] 6. Insert guide pin 155 #2 through the drill guide to dock on the superior facet.
[0159] 7. Make a small skin incision for the obturator 33 .
[0160] 8. Working tube 35 should be small oval or round with medial cutout to maximally medialize the working tube 35 .
[0161] 9. Advance the working tube 35 to the L5-S1 joint and dock.
[0162] 10. Drill the guide pin across the joint medial to lateral, rostral to caudal. If in proper position, advance across the joint to engage the ala.
[0163] 11. Drill across the joint with a cannulated drill.
[0164] 12. Check depth flouroscopically and measure.
[0165] 13. Pick appropriate screw length.
[0166] 14. Insert specially designed facet screw and protective bracket, secure tightly.
[0000] Procedure III: Posterior Lumbar Interbody Fusion (PLIF)
[0167] 1. First half of the procedure similar to microdiskectomy (Procedure I) except for the use of a larger diameter sized working tube 35 . Use a 20-25 mm round or elliptical diameter working tube 35 with a medial cutout to allow docking as close to midline as possible.
[0168] 2. Following diskectomy enlarge the laminotomy to accommodate the tools use for the specific PLIF such as Brantigan cage or Tangent.
[0000] Procedure IV: Transfacet Interbody Fusion (TFIF)
[0169] 1. Follow the same procedure as the PLIF in terms of selecting and inserting the Working Tube 35 .
[0170] 2. Following the diskectomy, resect the facet joint.
[0171] 3. Approach the posterolateral disc space through the medial ⅔ of the facet joint. Take care not to injure the exiting root above.
[0172] 4. Proceed with Brantigan cage instruments and interbody cages.
[0000] Procedure V: Pedicle Screw Instrumentation Technique
[0173] 1. Place the patient 151 Prone position on a Jackson Table.
[0174] 2. Guide pin 155 is docked on facet joint angled 30 degree lateral to medial in the plane between the longissimus muscle longitudinally and multifidus muscle medially.
[0175] 3. Make skin incision.
[0176] 4. Fascial incisor introduction.
[0177] 5. Introduce the obturator 33 working tube 35 assembly between the longissimus and multifidus and progressively open the obturator 33 tip ends of the legs 39 and 41 , gradually reaching from the joint above and the joint below.
[0178] 6. Advance the working tube 35 and retract the obturator 33 .
[0179] 7. Use the elliptical Working Tube size 2.5 cm wide and open up to 5 cm.
[0000] Procedure IV: Anterior Lateral Lumbar Diskectomy Fusion
[0180] 1. Mid lateral decubitus position left side up. Place a “waist roll” to prevent sag of the mid lumbar spine.
[0181] 2. Identify proper level of surgery fluoroscopically.
[0182] 3. Insert a guide pin 155 #1 percutaneously into the superior facet perpendicular to the spine.
[0183] 4. Measure depth skin to joint on the scaled guide pin 155 #1.
[0184] 5. Insert cannulated flag guide over guide pin 155 #1.
[0185] 6. Slide the drill guide to match the depth.
[0186] 7. Insert a guide pin 155 #2 down to the disc space.
[0187] 8. Make skin incision and insert fascial cover.
[0188] 9. Insert the working tube 35 and Obturator 33 combination.
[0189] 10. Progressively dilate the obturator 33 .
[0190] 11. Advance the working tube 35 .
[0191] 12. Perform anterolateral diskectomy and interbody fusion as taught above.
[0192] 13. Use a round or oval shaped retractor or lower tube hemicylindrical portion 65 and 69 as inserts preferably with distal end cutouts in each.
[0000] Procedure VII: Posterior Cervical Foramenotomy and Lateral Mass Plating
[0193] 1. The patient is placed in a prone position on a Jackson table.
[0194] 2. Fluoroscopic identification of the level of surgery is had.
[0195] 3. Percutaneously insert guide pin 155 with AP and lateral fluoroscopic views.
[0196] 4. Make the initial skin incision.
[0197] 5. Apply the working tube 35 with obturator 33 into the incision.
[0198] 6. Perform slow dilation of the muscle.
[0199] 7. Advance the working tube 35 and collapse and remove the obturator 33 .
[0200] 8. Proceed with surgery. Type of sleeve or lower tube hemicylindrical portion 65 should be round or oval with slanted and to match the slanted lamina.
[0201] 9. For application for Lateral mass plating use an oval working tube 35 for a greater exposure.
[0000] Procedure VIII: Anterior Cervical Diskectomy Fusion
[0202] 1. Begin with standard anterior cervical diskectomy fusion approach with a incision on the left or right side of the neck.
[0203] 2. Blunt finger dissection is performed between the lateral vascular structures and the medial strap muscle and visceral structures down to the prevertebral fascia.
[0204] 3. Establish the correct level to be operated on fluoroscopically and the guide pin 155 inserted into the disc.
[0205] 4. Apply the working tube 35 and obturator 33 combination and dock at the proper level of the anterior spring.
[0206] 5. Open the working tube 35 and obturator 33 .
[0207] 6. Mobilize longus colli muscle.
[0208] 7. Use special Bent Homen Retractor specifically design to retract the longus colli.
[0209] 8. Proceed with surgery.
[0000] Procedure IX: Anterior Lumbar Interbody Fusion
[0210] 1. Begin with the standard approach whether it is retroperitoneal, transperitoneal or laparoscopic.
[0211] 2. Apply the special anterior lumbar interbody fusion working tube 35 and obturator 33 . This is a design with a medial lateral opening. It is oval shape and preferably with skirts 133 and 135 . The distal end of the retractor sleeve is slightly flared outward to retract the vessels safely. There is a skirt 133 or 135 applied to the cephalad side and possibly to the caudal side.
[0212] 3. With the vessels and the abdominal contents safely retracted out of harms way, proceed with diskectomy and fusion.
[0213] One of the aspects emphasized up to this point for the system 31 is structure and circumstance to minimize the upper entry point of the surgery while providing an expanded working area at the distal end of the tube. Structures which achieve this geometry have been shown, and include a flared upper end so that the aperture remains open regardless of the angle of spread.
[0214] In other applications it is permissible to expand the aperture opening at the top of the working sleeve assembly. Expansion can be for the purposes of introducing further working devices into the working tube, as well as to expand and protect the visual field. For example, further working devices may include implant tools and their held implants, tools to insert plates and screws, and tools to manipulate all of these into their final positions.
[0215] Visual field protection can be introduced where the surrounding tissue may tend to flow, move or obstruct the surgical working field. Where the bottom-most portions of the spread apart hemicylindrical tube are spread apart, tissue tends to enter the space between the bottom parts of the tube. Additional guarding structure needs to be introduced.
[0216] a description of the desired articulation of what is hereinafter referred to as a working tube assembly 417 , and including the working tube hemicylindrical portions is begun with respect to FIG. 37 . The designation of working tube assembly 417 refers to all of the tube structures seen in the earlier FIGS. 1-36 and as seen in any of the following Figures. FIG. 37 is an isolated view of two hemicylindrical tube sections shown joined in a tubular relationship and indicating at least a pair of pivot axes on each hemicylindrical tube section.
[0217] At the top of the structure shown in FIG. 37 a dashed line indicates an optional fluted structure 419 . Fluted structure is omitted from the drawings for FIGS. 37-49 in order that the views from the top will not be obscured. The optional fluted opening 419 and is often employed both to maintain the visual field upon opening, as well as to make it easier to add instrumentation into the surgical field. This structure is recommended, as well as all reasonable accommodation to facilitate its use.
[0218] a first hemicylindrical tube 421 is shown in alignment with a second hemicylindrical tube 423 . Rather than having the upper ends flared out to maintain a circular visual field on a full open position, a clearance notch 425 is provided in first hemicylindrical tube 421 , while a clearance notch 427 is provided in second hemicylindrical tube 423 .
[0219] The lowermost extent of the clearance notches 425 and 427 coincide with an upper pivot axis 431 of first hemicylindrical tube 421 and upper pivot axis 433 of first hemicylindrical tube 421 . The pivot axes 431 and 433 may include supports either derived from structures going into or out of the first and second hemicylindrical tubes 421 and 423 . In the view of FIGS. 37-39 , the structures seen facing the viewer are repeated on the opposite side. Thus, pivot axes 431 and 433 are also located on the side opposite that seen in FIGS. 37-39 . The same is true for all of the numbered structures. In this position, the simultaneous pivoting about the pivot axes 431 and 433 of the first and second hemicylindrical tubes 421 and 423 will not cause interference by portions of the first and second hemicylindrical tubes 421 and 423 which would otherwise interfere.
[0220] Further, a lower pivot axis 435 is provided below the upper pivot axis 431 of first hemicylindrical tube 421 . Similarly, a lower pivot axis 437 is provided below the upper pivot axis 433 of second hemicylindrical tube 423 . The geometry and pivot points having been identified, double headed arrows illustrate that the pivot points should be able to move toward and away from each other. Ideally, the only limitation should be the interference from the lower ends of the first and second hemicylindrical tubes 421 and 423 with each other. Where the mechanism for moving the first and second hemicylindrical tubes 421 and 423 has maximum independence, secondary considerations of interference are eliminated and only the primary interference between the first and second hemicylindrical tubes 421 and 423 will remain. Where the control mechanism for movement is lesser than that which allows maximum independence, savings can be had in terms of complexity of the mechanism at the expense of the freedom of movement.
[0221] FIG. 37 illustrates the first and second hemicylindrical tubes 421 and 423 in a closely aligned relationship where the upper pivot axis 431 is closest to the upper pivot axis 433 and where the lower pivot axis 435 is closest to the lower pivot axis 437 . This is the position expected to be used for entry into the body of the patient, especially along with a guide (to be shown) which will be located within and extending below the assembled and parallel linear tube formed by first and second hemicylindrical tubes 421 and 423 to provide a reduced insertion resistance.
[0222] Ideally, the first and second hemicylindrical tubes 421 and 423 will be inserted as shown in FIG. 37 and then manipulated to a position shown in FIG. 38 . FIG. 38 is an isolated view of two hemicylindrical tube sections as seen in FIG. 38 which are angularly displaced apart about a shared first pivot axis on each of the hemicylindrical tube sections. The position in FIG. 38 is characterized by the fact that upper pivot axes 431 and 433 have the same separation as seen in FIG. 37 , but in which the lower pivot axes 435 and 437 have moved apart. The position seen in FIG. 38 will be likely achieved just after insertion and in which the internal tissues have been pushed apart. Depending upon the surgical procedure, the first and second hemicylindrical tubes 421 and 423 will be chosen based upon length, so that the lower end will be at the correct height for the tissues to be viewed, manipulated and treated. The action can continue until the lower ends of the first and second hemicylindrical tubes 421 and 423 are sufficiently spaced apart for view and manipulation of the tissues between and adjacent the lower ends. If there is a sufficient viewing opening based upon the original distance of separation of the upper pivot axes 431 and 433 , the procedure may continue through an aperture about the same size of the tube shape seen in FIG. 37 .
[0223] Where more of an opening is needed, the first and second hemicylindrical tubes 421 and 423 upper pivot axes 431 and 433 can move more widely apart until a position such as that seen in FIG. 39 is achieved. FIG. 39 is an isolated-view of the two first and second hemicylindrical tubes 421 and 423 which are angularly displaced apart about a shared second pivot axis on each of the hemicylindrical tube sections. It should be emphasized that the position seen in FIG. 39 is a position where both the first and second hemicylindrical tubes 421 and 423 are parallel and separated from each other, but this need not be the case. From the position seen in FIG. 38 , the upper pivot axes 431 and 433 can be moved apart from each other while the lower pivot axes 435 and 437 either remain a constant distance from each other or are brought together. This range of articulation described can be used to physically manipulates the tissues in contact with the first and second hemicylindrical tubes 421 and 423 for any number of reasons, including introduction of further instruments if necessary, as well as to react to changing conditions of tissue at the lower tube.
[0224] In both FIGS. 38 and 39 a pair of opposing edges 439 can be utilized to support structures introduced between the first and second hemicylindrical tubes 421 and 423 . Other structures can be used including depressions, apertures and internal projections, such as hooks or latches. An internal structure within the first and second hemicylindrical tubes 421 and 423 would pose little risk of nick to the patient and can be designed to do nothing more than have a minimal interference effect with respect to the visual field.
[0225] As will be shown, a number of external structures can be employed to achieve the relative separation positions of the upper pivot axes 431 and 433 , as well as the lower pivot axes 435 and 437 that nearly any type of angle can exist on either side of a parallel relationship between the first and second hemicylindrical tubes 421 and 423 , but that most will be in a range of from a parallel relationship to some form of angular relationship seen in FIG. 38 , where the upper ends at the clearance notches 425 and 427 are closer together than the lower ends distal to the upper pivot axes 431 and 433 and lower pivot axes 435 and 437 .
[0226] One example of a side shield 441 is seen in FIG. 40 . FIG. 40 is a plan view of a given width supplemental side shield 441 having a width of approximately the separation of the hemicylindrical tube sections as seen in FIG. 39 , while accompanying FIG. 41 is a top view of the supplemental side shield 441 of FIG. 40 emphasizing its shape. The side shield 441 can be of any shape, but is shown in a rectangular shape to correspond with the first and second hemicylindrical tubes 421 and 423 in a parallel position as seen in FIG. 39 . The side shield 441 has a main portion which includes a first side 443 and a pair of lateral engagement portions 445 . The side shield 441 can depend from a number of other structures, but the side shield 441 seen in FIGS. 40 and 41 utilize an offset surfaces as engagement portions 445 . This geometry, will, absent any interfering structures which are attached to manipulate the first and second hemicylindrical tubes 421 and 423 , enable the side shield 441 to be introduced linearly from the top of first and second hemicylindrical tubes 421 and 423 . The introduction of side shield 441 may be guided somewhat into engagement by the clearance otches 425 and 427 . Much smaller engagement portions 445 could be used to engage the outer edges 439 of the first and second hemicylindrical tubes 421 and 423 , so long as the orientation is so as to protect the surrounding tissues. FIG. 41 emphasizes the geometry and shows a second side 447 .
[0227] In the orientation shown, the second side 447 would face toward the inside of the general tube formed in the orientation of FIG. 39 . If two of the side shields 441 were used, one on either side of the opening seen in FIG. 39 , the tube shape would be closed on both sides, and an oval viewing area would be formed. It should be emphasized that the side shield 441 can depend from any structure, and not just the opposing edges 439 seen in FIG. 39 . Structure used to manipulate the first and second hemicylindrical tubes 421 and 423 can be used to both guide and secure any side shield 443 .
[0228] In terms of a structure to manipulate the first and second hemicylindrical tubes 421 and 423 , it is preferable that the upper pivot axes 431 and 433 may be urged toward and away from each other independently of the urging of the lower pivot axes 435 and 437 toward and away from each other independently. a mechanism which would prevent all manipulations of the first and second hemicylindrical tubes 421 and 423 to a position of binding is desirable, but its complexity may obstruct the surgical field. For example, it would be good to have a mechanism which would prevent upper pivot axes 431 and 433 from moving away from each other while the lower pivot axes 425 and 437 are in their close proximity as depicted in FIG. 37 . In some cases operator knowledge and skill will probably be required.
[0229] In terms of supporting the upper pivot axes 431 and 433 and lower pivot axes 425 and 437 , the pivoting and movement may be passive with mechanisms to push or pull directly on the first and second hemicylindrical tubes 421 and 423 or structures which are mechanically attached. As an example of the use of force and movement urging at the pivot points, FIG. 42 illustrates one such system as a pivoting thread support system 551 . The gearing is shown as unduly expansive to illustrate simply the action, but in reality, several gears may be used.
[0230] Further, since the a pivoting thread support system 551 is viewed from the top, and as operating the upper pivot axes 431 and 433 , a similar arrangement would be used for the lower pivot axes 425 and 437 . a set of four pivot fittings 553 provide a threaded interior spaced apart from the first and second hemicylindrical tubes 421 and 423 , or fittings supporting the first and second hemicylindrical tubes 421 and 423 . The fittings 553 enable the first and second hemicylindrical tubes 421 and 423 to tilt while keeping the threaded apertures in alignment.
[0231] a first threaded member 555 has a pair of threaded areas in which the threads are oppose pitched. The threads engaging the fitting 553 of first hemicylindrical tube 421 are set to urge first hemicylindrical tube 421 away from second hemicylindrical tube 423 , at the same time that the same turning of the first threaded member engages fitting 553 of first hemicylindrical tube 423 set to urge first hemicylindrical tube 423 away from second hemicylindrical tube 421 . This means that the turning of first threaded member 555 in one direction urges the first and second hemicylindrical tubes 421 and 423 evenly away from each other, and alternatively, the turning of first threaded member 555 in the opposite direction urges the first and second hemicylindrical tubes 421 and 423 evenly toward each other.
[0232] Likewise, a second threaded member 557 has a pair of threaded areas in which the threads are oppose pitched. The threads engaging the fitting 553 of first hemicylindrical tube 421 are set to urge first hemicylindrical tube 421 away from second hemicylindrical tube 423 , at the same time that the same turning of the first threaded member engages fitting 553 of first hemicylindrical tube 423 set to urge first hemicylindrical tube 423 away from second hemicylindrical tube 421 , but in an oppose orientation than the threads of first threaded member 555 . This means that the turning of second threaded member 557 in the other direction (while the first threaded member 555 is turned in a first direction) urges the first and second hemicylindrical tubes 421 and 423 evenly away from each other. a pair of over sized gears, including a first gear 559 associated with the first threaded member 555 , and a second gear 561 associated with the second threaded member 557 act to cause the first and second threaded members 555 and 557 to move simultaneously and oppositely. a knob 563 is used to manipulate both the first gear 559 , which manipulates the second gear 561 . In a realization in which more gears 559 and 561 are provided, the size of the gears can be reduced and for each intermediate gear, the sense of the threaded members 555 and 557 will change from opposite to same.
[0233] Referring to FIG. 43 , a surrounding frame system 571 is seen which is utilized to provide and enable pivoting and translation. A surrounding frame 573 has an open slot 575 which accommodates a pair of pins 577 and 579 which preferably have some tracking along the slot 575 to insure that neither the first hemicylindrical tube 421 nor the second hemicylindrical tube 423 are able to turn within the frame 573 . The opposite side of the frame 573 will have a similar slot 575 . However, where the structures which engage the slot are especially over sized, or where the structural integrity is sufficient, only one slot need be used. The structural dependence on the frame 573 should be such that the two opposing first and second hemicylindrical tubes 421 and 423 will always oppose each other and cannot twist away from each other and can only pivot along their long axis.
[0234] a turn fitting 581 enables a threaded member 583 to turn while being axially fixed to the first hemicylindrical tube 421 . The threaded member 583 may be threadably engaged to an internal thread 585 at the end of the frame 573 . In this case a knob 587 is used to manually turn the threaded member 583 independently to move the first hemicylindrical tube 421 to the left or to the right. A turn fitting is a structure which holds the end of the threaded member and allows the threaded member 583 to urge the fitting forward or backward while continuing to turn.
[0235] In the alternative, knob 587 may have an internal thread, and turned with respect to the threaded member 583 draw the threaded member out of the frame 573 . In this case, a spring (as will be shown) could be used to help reverse this operation. Where the knob 587 is internally threaded, the end of the threaded member may be fixed directly to its first hemicylindrical tube 421 .
[0236] In sum, there are three ways to affect motion, preferably the internal threads 585 enable the threaded member 583 to turn to urge first hemicylindrical tube 421 in both directions with respect to the frame 573 . In the alternative, the threaded member 583 may act only to urge the first hemicylindrical tube 421 , and the tubes 421 and 423 may have another mechanism urging them apart or simply move apart based upon other forces or other structures present. Third, the threaded member 583 may have an end anchored to the first hemicylindrical tube 421 with an internally threaded surface inside knob 587 to enable the knob 587 to be turned to cause the length of threaded member 583 to be withdrawn from the frame 583 . A spring, or other fitting can be used to help reverse the direction of travel. All of the knobs and threaded members shown hereafter have the ability for all three modes of action.
[0237] Similarly, a turn fitting 591 enables a threaded member 593 to turn while being axially fixed to the second hemicylindrical tube 423 . The threaded member 593 threadably engaged to an internal thread 595 at the end of the frame 573 .
[0238] a knob 597 is used to manually turn the threaded member 593 independently to move the second hemicylindrical tube 423 to the left or to the right.
[0239] Similarly, a second surrounding frame 573 has an open slot 575 which accommodates a pair of pins 601 and 603 having expanded heads which fit outside the slot 575 to provide tracking along the slot 575 to further insure that neither the first hemicylindrical tube 421 nor the second hemicylindrical tube 423 are able to turn within either of the frames 573 .
[0240] a turn fitting 611 enables a threaded member 613 to turn while being axially fixed to the first hemicylindrical tube 421 . The threaded member 613 is threadably engaged to an internal thread 615 at the end of the frame 573 . a knob 617 is used to manually turn the threaded member 613 independently to move the first hemicylindrical tube 421 , at its lower pivot axis 435 at the center of the pin 601 . Similarly, a turn fitting 621 enables a threaded member 623 to turn while being axially fixed to the second hemicylindrical tube 423 . The threaded member 623 threadably engaged to an internal thread 625 at the end of the lower located frame 573 . a knob 627 is used to manually turn the threaded member 623 independently to move the second hemicylindrical tube 423 to the left or to the right at its lower pivot axis 437 at the center of the pin 603 .
[0241] With the configuration of FIG. 43 , the position within the upper located frame 573 and separation of the pivot axes 431 and 433 (represented by the pins 577 and 589 ) can be exactly specified. Likewise, the position within the lower located frame 573 and separation of the pivot axes 435 and 437 (represented by the pins 601 and 603 ) can be exactly specified. In typical use, the knobs 617 and 627 and will be activated after insertion to achieve the configuration seen in FIG. 38 , and then followed by the use of the knobs 587 and 597 to achieve the configuration seen in FIG. 39 , if necessary. Thereupon the optional side shield 441 may be employed. Where a lesser separation than that seen in FIG. 39 is used, a narrower side shield 441 may be employed. In a surgical kit, several such shields 441 of different size and shape may be available.
[0242] Referring to FIG. 44 , a view looking down into the structure of FIG. 43 shows the overall orientation and further illustrates an optional securing tang 629 which may be used with either of the upper located or lower located frame 573 , and may be located in any position, or extended in any direction, to better enable the surgeon to stabilize and manipulate any of the assemblies 417 , 551 and 571 seen. Any structure can be used to help secure the frame 573 and or the first and second hemicylindrical tubes 421 and 423 . FIG. 44 is an equivalent view through the lower of the frames 573 , including the knobs 617 and 627 as the two frames 573 have equivalent action. Note that having complete control over both the separation, angular relationship, and position of the first and second hemicylindrical tubes 421 and 423 within the frame 573 will enable the surgical practitioner to position the line of sight of the working tube along the frame 573 length and to generally have complete control.
[0243] Also shown in FIG. 44 is an optional spring 630 which can be used to bias the force acting upon either of the first and second hemicylindrical tubes 421 and 423 , or it can be used to bias a knob 597 away from the frame 573 . Although shown as an option, the use of a spring 639 may contribute significantly where force is to be had in one direction only, as well as to lock a threaded member such as 593 into a turn fitting by keeping a pulling bias in place.
[0244] In some cases it may be desired to reduce the number of controls to accomplish certain objectives, such as simplicity, less controllability, less moving parts, inexpense, or the critical need for space about the upper part of any of the assemblies 417 , 551 and 571 . One example of an arrangement is seen in FIG. 45 . a frame 631 has an interior having one surface which may generally match one of the first and second hemicylindrical tubes 421 and 423 , and in this case first hemicylindrical tube 421 . The frame 631 may be attached to the first hemicylindrical tube 421 by tack welding or the like, or other means. a single threaded member 633 includes a knob 635 . a structure 637 can be either an engagement turning block to enable the threaded member 633 to both push and pull on the second hemicylindrical tube 423 , or it may simply be a wear block to allow the threaded member 633 to push against it and to protect the second hemicylindrical tube 423 from wear.
[0245] Because half of the tube assembly of first and second hemicylindrical tubes 421 and 423 is supported by the frame 631 , the second hemicylindrical tube 423 is left to move only slightly and assuming that FIG. 45 is an upper view and that the pivoting of the second hemicylindrical tube 423 is accomplished at a lower level, especially at the level of lower pivot axis 437 , the frame 631 is left to control second hemicylindrical tube 423 by simply pushing, or by pushing and pulling. Where structure 637 is a turning block, there is a bulbous expansion at the end of threaded member 633 which snaps into structure 637 as a turning block and is free to turn and both push and pull second hemicylindrical tube 423 . The threaded member 633 is threadably engaged into an internal threaded bore 639 within the frame 631 .
[0246] Referring to FIG. 46 , one embodiment of a manipulative structure which works well with the structure of FIG. 45 is shown. The structure shown is a partial section taken at the lower pivot axis level and includes means for pushing and pulling, or pushing alone. Preferably, when used with the structure of FIG. 45 , it will include pushing and pulling, especially if the structure of FIG. 45 performs pushing alone. Either of the structures in FIG. 43 at either the upper or lower pivot axis levels can be substituted for either of the structures shown in FIG. 45 and 46 as the structures in FIG. 43 provide both pushing, pulling, pivoting and level support.
[0247] Where the structures of FIG. 45 provides both pushing and pulling, it can be used along with a second structures at the lower pivot axis as any structure which provides both pushing and pulling will also provide some pivoting support. Further, the structure shown in FIG. 46 is hinged to provide additional pivoting support. The structure of FIG. 46 can be used at either the upper pivot axes 431 and 433 or the lower pivot axes 435 and 437 . Both the structures of FIG. 45 and 46 demonstrate clearly that lesser control structures than are shown in FIG. 43 can be used to control the first and second hemicylindrical tubes 421 and 423 , along with lesser control inputs, and less control specificity, but also with less moving parts and a lesser mechanical complexity.
[0248] Referring again to FIG. 46 , second hemicylindrical tube 423 is seen as tack welded to a reinforcement 651 . The purpose of reinforcement 651 is to provide an expanded thickness of material so that pivoting can occur closer to the edge 439 as is possible. It is further possible to continue the extent of the reinforcement 651 and its pivot point in the direction of first hemicylindrical tube 421 if the other geometries of the other components permit. Reinforcement 651 contains a pair of threaded bores 653 , each of which accommodates one of the threaded screws or bolts 655 shown. The bolts 655 each extend through one end of a “U” shaped fitting 657 , so that the reinforcement 651 and attached second hemicylindrical tube 423 pivots with respect to the fitting 657 . a threaded member 659 engaged an internal threaded bore 671 , and has a knob 673 for ease of manual operation.
[0249] The threaded member is connected to a turn fitting 675 the first hemicylindrical tubes 421 to be moved toward and away from second hemicylindrical tube 423 . The use of the structure of FIGS. 45 and 46 may be used together to give the ability to provide control, although not as much control as is seen in FIG. 43 . Also seen is an Referring to FIG. 47 , another possible realization is seen, combining the control mechanisms of selected portions of FIGS. 37-46 , combined with other possible options. An open frame system 691 is seen as having a frame 693 which is either open on at least one side, or which has a side expanded to a distance sufficient to introduce other structures to expand in that direction. Some of the components previously seen include pins 577 and 579 extending through slot 575 . Pins 577 and 579 may have extended vertical and horizontal extent to garner additional stability from the frame 693 , especially where one side is open.
[0250] Other structures may be used to insure that neither the first hemicylindrical tube 421 nor the second hemicylindrical tube 423 are able to turn within the frame 573 . Also seen are turn fitting 581 , threaded member 583 , knob 587 , turn fitting 591 , threaded member 593 , and knob 597 . The view of FIG. 47 is from above, and thus the structures most closely correspond to the upper structures seen in FIGS. 43 and in FIG. 44 .
[0251] As can be seen in FIG. 47 , a four point retractor system can be formed with the components and structures of the foregoing Figures. The first and second hemicylindrical tubes 421 and 423 are shown in the open position. On the longer connector arm of the frame 693 , a side shield 695 is supported. The side shield 695 can derive its ability to hold tissue out of the visual field by being locked down onto the frame 693 in the same manner as a wrench fits a bolt head. In this configuration, the side shield can be inserted into the center of the surgical field and then rotated into position and moved down slightly to lock it into place. On the opposite side from side shield 695 is a retractor 697 which has a flat portion entering the surgical field and which is controlled from a point remote with respect to open frame system 691 . An angled portion 699 turns from the flat portion seen entering the surgical field and extends down into the area between the open first and second hemicylindrical tubes 421 and 423 .
[0252] Also seen are a series of small circular structures 701 about the peripheral upper surface of first and second hemicylindrical tubes 421 and 423 . These structures are at least one of embedded fiber optics and ports for accepting fiber optics. The apertures formed in the metal open at a slight angle to the inside of the first and second hemicylindrical tubes 421 and 423 to direct light into the surgical field without producing a back reflection or other scatter. In cases where the fiber optic is permanently affixed, a light ring section can simply be snapped to or placed on the first and second hemicylindrical tubes 421 and 423 . In cases where the apertures are provided, surgery can continue without fiber optics, or a fiber optics set can be added which can range from an illuminated ring (relying on low angle of incidence and snells law) to direct light through the openings which open to the inside of the first and second hemicylindrical tubes 421 and 423 at a low angle of incidence. Intermediary solutions, such as a light ring having a series of short fiber optic members for insertion into the apertures can be used. To facilitate the use of fiber optics, the hemicylindrical tubes 421 and 423 may be made from a composite material in which the fiber optic components may be present during formation of the tube structures. Other material may be used for tubes 421 and 423 , including materials that either transmit light or have portions which transmit light.
[0253] As an alternative to the three sided frame 693 , the open portion of the frame could be enclosed by an expandable member 703 which can have any manner of interlock with the three sided frame 693 . One such interlock is illustrated as simply an annular piston dependence where the expandable member 703 includes a smaller tubular insert 705 which fits closely into a matching bore 707 seen in the terminal ends of the three sided frame 693 . The expandable member 703 can be used to lend additional support to the three sided frame 693 , especially forces produced by the threaded members 583 and 593 . The expandable member 703 is also useful to help support the retractor 697 where such provision is made. The main purpose of expandable member 703 is the adjustability to give greater clearance and access. The same adjustability could be had on the side of three sided frame 693 which supports side shield 695 , especially with a more complex mechanism to enable the frame expansion to be locked into place. A locking mechanism for expandable member 703 is not shown so that the drawings may be simplified, but lock ability can be achieved in the same manner as any metal to metal frame construction known in any field of art.
[0254] Referring to FIG. 48 , a side view of the side shield 695 is seen. The clearance for locking onto the frame 693 is about the same as the width of the frame 693 so that non rotational fixation can be transmitted along the length of the side shield 695 .
[0255] Referring to FIG. 49 , one possible configuration is seen for a variable depth guide 711 which is utilizable with any of the devices seen in FIGS. 37-46 or any other tubular, minimally invasive system. Variable depth guide 711 has a handle 713 controlling a shaft 715 . Shaft 715 has a through bore 717 which is used to insert a guide line or guide pin to help insert any minimal access system seen in the earlier Figures.
[0256] a translatable detent ring 719 interacts with a series of detent indentations 721 . The position of the detent ring 719 will correspond to the lengths of the first and second hemicylindrical tubes 421 and 423 with which the variable depth guide 711 is used. Once the practitioner inserts the variable depth guide 711 into any assembly containing a first and second hemicylindrical tubes 421 and 423 , the necessary height can be adjusted so that the tip of the variable depth guide 711 extends just beyond the lower extent of the joined first and second hemicylindrical tubes 421 and 423 . The height is adjusted by forcing the detent ring 719 to the proper detent indentation 721 , and then inserting it into a closely associated first and second hemicylindrical tubes 421 and 423 to form an overall bullet shape for insertion, preferably a guide pin 155 . Once inserted, the variable depth guide 711 is removed. The detent ring 719 carries a frusto-conical surface 723 where it is used with first and second hemicylindrical tubes 421 and 423 having fluted top areas as seen in FIG. 37 and in previous figures. Any mechanism can be used to achieve a detent action, including an internal pressure ring or a spring loaded bar, or protruding ball bearings. The positional stability of the detent ring can be specified by the spring action of the detent member, and should be sufficiently stable to enable deliberate manual fixation with no inadvertent movement occurring even where significant resistance is encountered.
[0257] Referring to FIG. 50 is a vertical plan view looking down upon an expandable frame system 751 which uses detents to set the frame size and which uses an angular distribution system. A frame is used as a support and reference point to manipulate a working tube in much the same way as FIGS. 37-47 . Expandable frame system 751 enables the user to control the size of the operating theater as needed. Where the task can be accomplished with minimum opening access, such minimum opening is all that needs to be taken. Where greater access is needed, the expandable frame system 751 provides both an expanded work space, and additional surfaces for support of other instrumentation.
[0258] As before, the retractor blades are seen as a first hemicylindrical tube 753 having an upper flared portion 755 and a second hemicylindrical tube 757 having an upper flared portion 759 . Each of the first and second hemicylindrical tubes 753 and 757 have two points of variable pivoting attachment.
[0259] Hemicylindrical tube 753 has a pivot bar 781 which may be attached somewhat tangentially to the first hemicylindrical tube 753 , or may include a pair of extensions attached to the outside of the first hemicylindrical tube 753 . Likewise, hemicylindrical tube 757 has a pivot bar 783 which may be also attached somewhat tangentially to the first hemicylindrical tube 753 in the same manner.
[0260] Pivot bar 781 has circular lands 785 which fit into support fittings 787 . Likewise pivot bar 783 also has circular lands 785 which fit into support fittings 787 . The support fittings 787 , as seen from above, show the lands 785 . In this configuration the lands 785 can be dropped in from above. This is an over-simplified illustration, as some other locking mechanism can be utilized, including ball shape instead of disc shape or other. It would be preferable that the manner of pivoting engagement will firstly enable an ease of assembly and disassembly and secondly provide good stability against dislodgement with respect to any forces experienced when the expandable frame system 751 is in an operational position.
[0261] Above the point of pivot of the pivot bars 781 and 783 , each of the first and second hemicylindrical tubes 753 and 757 are fitted with a pivot bearing fitting 791 . The pivot bearing fittings 791 can depend from either the first and second hemicylindrical tubes 753 and 757 or their upper flared portions 755 and 759 . The pivot bearing fittings 791 can be hinge type of ball type, or any other type which will enable the upper part of the first and second hemicylindrical tubes 753 and 757 tp be force moved to pivot them with respect to the pivot fittings 781 and 783 in either direction.
[0262] The pivot bearing fitting 791 is engaged by a cooperating fitting 793 which enables the pivot bearing fitting 791 to pivot with respect to the cooperating fitting 793 . The cooperating fitting 793 is moved with a threaded member 795 , having a thumb control wheel as a tilt screw knob 797 . In the drawings of FIG. 50 and 51 , the fittings 791 are located above the pivot bars 781 and 783 , but they need not be.
[0263] In the embodiments of FIGS. 50 and 51 the movement of the axes of the pivot bars 783 are affected by the expansion of a frame support including a first lateral member 801 and a second lateral frame member 803 . The ends of firs and second lateral members 801 and 803 are connected to two telescoping frame members 805 and 807 . Telescoping frame member 805 has a central hinge box 811 which is positioned between a first sleeve 813 and a second sleeve 817 . The central frame section pivotally supports a pair of internal spreading bars, including a first spreading bar 821 which extends within first sleeve 813 and a second spreading bar 823 having a ratchet or detent structure (to be described) which extends within second sleeve 817 .
[0264] Although not shown in FIGS. 50 and 51 , the spreading bars 821 and 823 will preferably have an internal gear mesh so that both will preferably have an equal angular displacement with respect to the central hinge box 811 . The articulation within the central hinge box 811 will enable the selection of three angular frames of reference with regard to the surface of a patient, namely the angle of first sleeve 813 , the angle of central hinge box 811 , and the angle of second sleeve 817 . Where other objects, such as retractors, light sources etc have to be anchored, three reference angle surfaces are available.
[0265] The spreading bars 821 and 823 are thus axially fixed with respect to the central hinge box 811 , with the spreading bars 821 and 823 axially slidable within the first and second sleeves 813 and 817 . Many mechanisms can be utilized to fix the position of the spreading bars 821 and 823 within the first and second sleeves 813 and 817 . One such mechanism is show schematically in its most rudimentary form in FIG. 38 as including a pivot support 825 which supports a lever 827 . The lever 827 operates against a spring 829 and operates an engagement member 831 with respect to detent structures 833 located on the spreading bars 823 . These structures form a first ratchet stop 835 . Operational depression of the lever 827 disengages the detent structures 833 of the spreading bar 823 to slide within the sleeve 817 and releasing the lever 827 enables the spring 829 to act to cause engagement of the engagement member 831 . With this mechanism, or a similar mechanism, the expansion of the expandable frame system 751 can be controlled, with the expansion of the second lateral frame member 803 away from the central hinge box 811 . Similarly the first lateral member 801 is independently movable away from central hinge box 811 with the use of a mechanism similar to the one shown with respect to the pivot support 825 , lever 827 , spreading bar 823 engagement member 831 , and detent structures 833 .
[0266] The detent structures 833 could be made triangular shaped for sliding in one direction with hold against the other direction. A second mechanism similar to the one shown with respect to the pivot support 825 , lever 827 , spreading bar 823 engagement member 831 , and detent structures 833 is omitted from FIGS. 50 and 51 for simplicity. Regardless of the structure, the expandable frame system 751 can be exactly positioned. Other assisted mechanisms can be employed, including a threaded member or a pinion or other device which will give the user mechanical advantage in extending the expandable frame system 751 . Further, the fittings illustrated, including pivot bars 781 & 783 with circular lands 785 and slip fitting into support fittings 787 , as well as the pivot bearing fitting 791 and cooperating fitting 793 suggest that the expandable frame system 751 may be added to the operating theater after the first and second hemicylindrical tubes 753 and 757 have been employed into the surgical opening. This will free the surgeon to position the first and second hemicylindrical tubes 753 and 757 without having to handle the supporting frame members.
[0267] Between the other ends of the first lateral member 801 and second lateral frame member 803 the second telescoping frame member 807 also has a central hinge box 811 . Again, the central hinge box 811 which is positioned between a first sleeve 813 and a second sleeve 817 . The central frame section pivotally supports a pair of internal spreading bars, including the first spreading bar 821 within first sleeve 813 and the second spreading bar 823 which extends within second sleeve 817 .
[0268] The interfit between the first and second sleeves 813 and 817 and the first and second spreading bars 821 and 823 in both the first and second telescoping frame members 805 and 807 is expected to be of sufficiently tight tolerance so that both of the central hinge box 811 remain directly across from each other. If the latch mechanism supported by the second lateral frame member 803 is released the second lateral frame member 803 should move away from the central frame sections 811 . In other words, one of the central frame sections 811 should not displace to a position other than directly across from each other.
[0269] The second telescoping frame member 807 could have the same mechanism as the first telescoping frame members 805 , but a slightly different mechanism is shown in order to emphasize the variability which can be employed with respect to the expandable frame system 751 . A retention housing 837 is attached to second sleeve 817 and houses a lock pin 839 and a spring 841 which urges it int the second sleeve 817 where it lockably interfits with the detent structures 833 . These structures may be collectively referred to as a second ratchet stop 843 . The expansion of the expandable frame system 751 , if properly toleranced will enable the right and left sides to be independently controlled in movement toward and away from the away from the central hinge box 811 . The actuation of one release mechanism will enable balanced displacement of its associated first or second lateral members 801 and 803 .
[0270] Movement of the associated first or second lateral members 801 and 803 by one of the latches shown gives a parallel distance separation of the first hemicylindrical tube 753 with respect to the second hemicylindrical tube 757 , regardless of their respective angular positions (assuming no interference). However, the angularity of the first and second hemicylindrical tube 753 and 757 are set by the movement of the threaded member 795 . As such, the expandable frame system 751 enables independent angularity adjustment for the first and second hemicylindrical tube 753 and 757 and independent parallel separation for the first and second hemicylindrical tube 753 and 757 based upon expansion of the frame.
[0271] Other features seen in FIGS. 50 and 51 include a support tang 845 and a pair of manipulation sphere projections as spreader projections 847 to assist in manually manipulating the expandable frame system 751 . FIG. 51 illustrates a condition in which the expandable frame system 751 is in an expanded orientation, with first lateral member 801 and second lateral frame member 803 equally expanded from central hinge box 811 . Either of the first and second lateral members 801 and 803 could have been extended from the central hinge box 811 . This feature gives the surgeon the flexibility to adjust the positioning of the central hinge box 811 . The central hinge box 811 may also have support structures for other instrumentation, including bores 849 in the central hinge box 811 such as a bookwalter support (to be shown). Bores 849 can be used for locational registry or for threaded attachment. A bookwalter device is especially useful for supporting an additional retractor, in addition to the first and second hemicylindrical tubes 753 and 755 .
[0272] Referring to FIG. 52 , a side view of the system of FIGS. 50-51 illustrates further details. The angle of the incline of the upper flared portions 755 and 759 are illustrated. A scale 851 helps the surgeon to ascertain the depth to which the first and second hemicylindrical tubes 753 and 755 are inserted into the patient (with the additional consideration of any further extension which may be added to the first and second hemicylindrical tubes 753 and 755 ).
[0273] One possible configuration for the first and second hemicylindrical tubes 753 and 755 , include the use of an upper tube portions along with a lower extension. The scale 851 could also be utilized, in conjunction with the extension to indicate depth. A notch 853 can be used as a reference surface to engage an extension. Another surface can include a raised portion or depressed portion matched to an extension (as will be shown) in each of the first and second hemicylindrical tubes 753 and 755 .
[0274] FIG. 53 illustrates a double pivot hinge fitting within the central hinge box 811 . A pair of threaded members 861 extend into machined spaces within central hinge box 811 and hold the spreading bars 821 and 823 into a close proximate location such that the complementary gear teeth 863 located on the abutting ends of the spreading bars 821 and 823 intermesh with each other. This arrangement insures that the angular displacement of the spreading bars 821 and 823 with respect to the central hinge box 811 will be equi-angular. This is shown in FIG. 54 where the angle y on both sides indicates equi angular displacement.
[0275] Referring to FIG. 55 , a top view of the central hinge box 811 illustrates a bookwalter retractor device 871 mounted on the upper surface of the central hinge box 811 . The bookwalter device has a central through bore 873 through which a retractor rail or extension may pass. Typically the retractor extension (not shown) will have a series of detents similar to the detents 833 seen in FIG. 53 . As the detents emerge from the through bore 873 , they are engaged by a pivoting latch 875 which operates under urging force from a spring 877 . A turnbuckle or other force control structure would enable operation of a gear mechanism to move any type of “east west” retractor blades towards or away from the center.
[0276] Referring to FIG. 56 , a plan view is shown of a remote force retraction system employing many of the structures seen in FIGS. 50-55 , but with a remote force system such as disclosed and shown in U.S. Pat. No. 4,747,394, to Robert S. Watanabe, and incorporated by reference herein. The technique of application of remote force to leave the surgical field open as applied to the expandable frame system 751 is seen as an open minimally invasive expansion system 901 . At the surgical field, many of the components previously seen have the same numbering.
[0277] A pinion box 903 carries a (removable) key insertable gear 905 seen inside an aperture 907 having teeth 911 which engage a linear gear 913 on a first rack 915 , and which also engage linear gear 917 on a second rack 919 . Rack 915 is fixedly attached to a first main support 921 while rack 919 is fixedly attached to a second main support 923 . As the gear 905 is turned clockwise, the rack 915 freely feeds through an aperture 931 (seen in dashed line format) in second main support 923 , through the pinion box 903 and pushes first support 921 father away from the pinion box 903 . At the same time, the gear 905 pushes the rack 919 freely feeds through an aperture 933 (seen in dashed line format)in first main support 921 , through the pinion box 903 and pushes second support 923 farther away from the pinion box 903 .
[0278] The result is that two strong support members, namely first support 921 and second support 923 are being forced away from each other remotely, by the turning of the key insertable gear 905 . Note that the areas on either side of the first and second hemicylindrical tubes 753 and 755 are clear to enable other structures to be employed, either unsupported, or independently supported, or possibly supported from structures which support first support 921 and second support 923 .
[0279] A ratchet latch lever 935 is mounted is mounted to pivot with respect to first support 921 by the action of a spring 937 . The ratchet latch lever 935 is fork shaped to fit around the tip fixed end of rack 914 and to actuate an internal latch 939 which operates within the first support 921 between the first rack 915 and second rack 919 .
[0280] Also seen is a hinge 941 on first support 921 , and a hinge 943 on second support 923 . The hinges 941 and 943 should preferably have the same angular range and would ideally be from about zero degrees (flat) to about fifteen degrees down with the hinges 941 and 943 rising to form the apex. The hinges 941 and 943 permit the lateral force components to be angularly sloped down, or draped to provide an angled working presentation, and to take up less lateral space in the same plane as the working area. Beyond the hinges 941 , the first support 921 is connected to a first extended support 945 while the second support 923 is connected to second extended support 947 .
[0281] Both the first and second extended supports 945 and 947 include angular extensions 949 which support the support fittings 787 and other structures previously shown. The first and second extended supports 945 and 947 also support tilt screw knob 797 and manipulation sphere projections as spreader projections 847 . The support details for the first and second hemicylindrical tubes 753 and 755 is essentially the same as was shown for FIGS. 50 & 51 .
[0282] In addition, an optional pair of tilt fittings enable the first and second extended supports 945 and 947 to tilt where it may be more advantageous to locate open minimally invasive expansion system 901 over portion of a patient's body which is angled. A first tilt adjustment fitting 951 can be used to provide tilt to the main extent of first extended support 945 , while a second tilt adjustment fitting 953 can be used to provide tilt to the main extent of second extended support 947 . Typically the first and second tilt adjustment fittings 951 and 953 will be used to set the tilt before an operation begins. As to both of the first and second tilt adjustment fittings 951 and 953 , a support plate 955 is rigidly supported by the portion of the respective first and second extended supports 945 and 947 nearest the hinges 941 . The support plate 955 supports a retention housing 837 . The retention housing includes a lock pin 839 and a spring 841 which urges it through apertures of the support plate 955 and across to a selector plate 957 . As to both of the first and second tilt adjustment fittings 951 and 953 , the selector plate 957 is rigidly supported by the portion of the respective first and second extended supports 945 and 947 on the other side of the respective first and second tilt adjustment fittings 951 and 953 .
[0283] Although shown in somewhat schematic view, a tilt pin 961 joins portions of first extended support 945 rigidly while enabling the tilting of the portion of the first extended supports 945 on one side of the first tilt adjustment fitting 951 to pivot with respect to the portion of the first extended supports 945 on the other side of the first tilt adjustment fitting 951 . Likewise, a tilt pin 963 joins portions of second extended support 947 rigidly while enabling the tilting of the portion of the second extended supports 947 on one side of the second tilt adjustment fitting 953 to pivot with respect to the portion of the second extended supports 947 on the other side of the second tilt adjustment fitting 953 . In reality, in order to transmit the force rigidity, more complex internal fittings may be utilized. The support plate 955 and selector plate 957 are simple mechanical mechanisms which are located far enough off the axis of pivot to enable selection of a number of angular positions.
[0284] Other structures can be supported from the both the first and second extended supports 945 and 947 . A pair of slot openings 965 at the far ends of the first and second extended supports 945 and 947 can support additional instrumentation. In addition, the first and second extended supports 945 and 947 include structures 965 which may be apertures or projections or other structures which will enable support to be derived for other retractors. A cross support 971 supports a mechanical housing 973 through which a linear gear 975 can extend. A retractor 976 (which can be of any type) is attached to one end of the linear gear 975 . A hand wheel 977 operates a gear 979 which moves the linear gear 975 through the housing 973 . This assembly is a first cross supported retractor set 981 . A second cross supported retractor set 983 is also shown. This gives the surgical practitioner good control and leverage to operate the “north-south” retractors.
[0285] An illustration of an extension previously mentioned is illustrated in FIG. 57 which illustrates a top view of a hemicylindrical extension 991 standing alone. Hemicylindrical extension 991 may have several pair of inwardly directed members 993 (or a single large inwardly directed member 993 ) for engagement against the notches 853 seen in FIG. 52 . An inwardly directed angled “snap” protrusion 995 springs into a matching opening on either of the first and second hemicylindrical tubes 753 and 755 . The hemicylindrical extension 991 will fit on the outside of the matching first or second hemicylindrical tubes 753 and 755 and the force on the hemicylindrical extension 961 is expected to be inward at its lower extent during spreading.
[0286] Referring to FIG. 58 , a side semi-sectional view is shown. A lower portion of first hemicylindrical tube 753 having groove 853 , and a slot 997 is seen in a sectional view. Adjacent the semi section hemicylindrical tube 753 is the hemicylindrical extension 991 in an attached position. The upper end of he notch 853 fixes against up motion, and the slot 997 fixes against down motion when it engaged with inwardly directed angled “snap” protrusion 995 . A stable support relationship is shown.
[0287] Referring to FIG. 59 , a view looking down into the inside of the combination of the first hemicylindrical tube 753 and hemicylindrical retractor tube extension 99 of FIGS. 57 and 58 . It can be seen how the large inwardly directed members 993 wrap around the groove 853 and can be slid upwardly until the inwardly directed angled “snap” protrusion 995 engages.
[0288] Referring to FIG. 60 , a view looking down onto the outside of the combination of the first hemicylindrical tube 753 and hemicylindrical retractor tube extension 99 of FIGS. 57-59 is seen. In addition, the pivot bar 781 with circular lands 785 are also seen below the pivot bearing fitting 791 , for reference. The large inwardly directed member 993 is partially shown in dashed line format. The bottom of the hemicylindrical extension 991 may be of any shape.
[0289] Referring to FIG. 61 , an exploded view of a frame retractor system 1001 is seen. The articulation of the frame retractor system 1001 is achieved by using a main outer first frame section 1003 which laterally overlaps a smaller laterally inner second frame section 1005 . The frame sections 1003 and 1005 are joined and circumferentially envelop a first retractor member 1007 and a second retractor member 1009 . As seen in the earlier embodiments, each degree of motion achieved in retraction, namely separation and independent angular articulation each require a series of actuators and it may be desirable to reduce the number of actuators both for simplicity and quick controllability. In the configuration seen in FIG. 61 , the angular articulation of the second retractor member 1009 is surrendered with respect to the second frame section 1005 , but the second frame section 1005 is made limitingly pivotable with respect to the first frame section 1003 .
[0290] Beginning further discussion at the left of FIG. 61 , a threaded actuator 1111 includes a threaded shaft 1113 , an expanded diameter actuator knob 1115 , and a rotation capture fitting 1117 which will enable the threaded actuator 1111 to be captured axially and yet turn. The threaded actuator 1111 threaded shaft 1113 engages an internally threaded bore 1119 within the second frame section 1005 to enable it to be axially moved through the second retractor member 1009 .
[0291] Second frame section 1005 includes a pair of internally disposed slots 1121 , each of which is interrupted by a vertical accommodation slot 1123 . Immediately adjacent the internally disposed slots 1121 are internally threaded bores 1125 . The uppermost ends of the overall “U” shape of the second frame section 1005 includes an angled portion 1127 which is used in combination with other structures to limit the amount of pivot of the second frame section 1005 with respect to the first frame section 1003 .
[0292] Second retractor member 1009 has thickened structurally reinforced upper head portion 1131 having a pair of outwardly disposed tongues 1133 which slidably fit within the slots 1121 . Second retractor member 1009 has a lower extension member 1135 which may include an insertion accommodation slot 1137 . The insertion accommodation slot 1137 has a lower extent which curves into the lower extension member 1135 to guide the terminal end of any member inserted into the insertion accommodation slot 1137 inwardly. Insertion accommodation slot 1137 has an upper end which opens from an upper surface of the reinforced upper head portion 1131 .
[0293] A set screw 143 is seen over and insertable into a threaded bore 1145 which leads into a position to partially obstruct a bore (not seen in FIG. 61 ) and capture the rotation capture fitting 1117 within the thickened structurally reinforced upper head portion 1131 .
[0294] The first retractor member 1007 also has a thickened structurally reinforced upper head portion 1151 , but has a pair of pivot bores 1153 , one of which is visible in FIG. 61 . First retractor member 1007 also has a lower extension member 1155 which may also include an insertion accommodation slot 1157 . The insertion accommodation slot 1157 has a lower extent which also curves into the lower extension member 1155 to guide the terminal end of any member inserted into the insertion accommodation slot 1157 inwardly. Insertion accommodation slot 1157 has an upper end which opens from an upper surface of the reinforced upper head portion 1151 .
[0295] From an upper surface of the reinforced upper head portion 1151 , an upper actuation block 1161 is seen as having a key slot 1163 extending vertically throughout its length. The vertical length of the key slot 1163 enables a member to both pull and push the upper actuation block 1161 as it angularly tilts since the key slot 1163 will operate to enable pushing and pulling throughout a range of angles assumed by the first retractor member 1007 .
[0296] First frame section 1003 includes a more distal pair of frame pivot bores 1171 , which are aligned with each other and also alignable with the internally threaded bores 1125 of second frame section 1005 . First frame section 1003 also includes a less distal pair of internally threaded bores 1173 , which are aligned with each other and also alignable with the pair of pivot bores 1153 of the reinforced upper head portion 1151 of the first retractor member 1007 . A pair of internally threaded bores 1173 are engaged by a pair of externally threaded set screws 1175 to gather support to further engage pivot bores 1153 carried by the thickened structurally reinforced upper head portion 1151 of the first retractor member 1007 . Threaded set screws 1175 enable first retractor member 1007 to pivot with respect to first frame section 1003 .
[0297] Generally, the first frame section 1003 has a first level which includes the more distal pair of frame pivot bores 1171 and the less distal pair of internally threaded bores 1173 . This level may be on a corresponding first level of second frame section 1005 and a same first level on second frame section 1005 is seen to include the internally threaded bores 1125 , and the internally threaded bore 1119 . As a result, the threaded actuator 1111 acts to move the second retractor member 1009 at a level directly across from the pivoting connection of the pivoting connection of the first retractor member 1007 to the first frame section 1003 and directly across from a pivoting connection of first frame section 1003 to second frame section 1005 (as will be shown).
[0298] A second level of first frame section 1003 is seen as a raised fitting 1181 . The raised fitting 1181 is a block which supports an internally threaded bore 1183 at a second level, above the first level occupied by the more distal pair of frame pivot bores 1171 and the less distal pair of internally threaded bores 1173 .
[0299] To the right of internally threaded bore 1183 , a threaded actuator 1191 includes a threaded shaft 1193 , an expanded diameter actuator knob 1195 , and a rotation capture fitting 1197 which will enable the threaded actuator 1191 to be captured horizontally within the upper actuation block 1161 key slot 1163 . Capture of the rotation capture fitting 1197 will allow it to urge the upper actuation block 1161 forward and rearward to cause the first retractor member 1007 to pivot. The key slot 1163 will continued engagement of the rotation capture fitting 1197 regardless of the angle of the first retractor member 1007 .
[0300] A pair of main threaded members 1199 each have an externally threaded portion 1201 and a knob 1203 . The threaded portions pass through the more distal pair of frame pivot bores 1171 and threadably engage the internally threaded bores 1125 of the second frame section 1005 . The knobs 1203 of the pair of main threaded members 1199 can be tightened to fix the angle of the first frame section 1003 with respect to second frame section 1005 . Also seen is a small bevel cut 1205 on the thickened structurally reinforced upper head portion 1151 to better enable the thickened structurally reinforced upper head portion 1151 to tilt forward.
[0301] Referring to FIG. 62 , a view of the assembled frame retractor system 1001 is seen. The co-planarity of the first and second frame sections 1003 and 1005 is seen. In the assembled position, it is more readily seen that the threaded actuator 1191 can actuate the upper actuation block 1161 away from the raised fitting 1181 . It can also be seen that the co-planarity of the first and second frame sections 1003 and 1005 can be maintained even as the thickened structurally reinforced upper head portion 1131 and lower extension member 1135 move parallel to the left.
[0302] Referring to FIG. 63 , a perspective view of the frame retractor system from the same perspective as seen in FIG. 61 is illustrated as being fitted with a fiber optic illuminator seen as a length of fiber optic cable 1211 which is guided into the insertion accommodation slot 1137 . As could be noted from FIGS. 61 and 62 , the slot is a key-type slot having an opening into the inside of the lower extension member 1135 . The fiber optic cable 1211 can thus be set to emit at a terminal end 1213 , any point near the terminal end, or along the length of the lower extension member 1135 through the portion of the slot along the length of the lower extension member 1135 .
[0303] Also noted in FIG. 63 is the upward angular displacement of the second frame section 1005 with respect to the first frame section 1003 . Note that the pivot axis is about a line between the knobs 1203 , and through the more distal pair of frame pivot bores 1171 and pair of pivot bores 1153 which were better seen in FIG. 61 . Turn arrows are shown around the knobs 1203 as they can be slightly loosened or tightened to control the tension and capability to hold or change the angle of the second frame section 1005 with respect to the first frame section 1003 .
[0304] Also note that regardless of the angular position of the second frame section 1005 with respect to the first frame section 1003 seen in FIGS. 61 and 62 that the threaded actuator 1111 can be independently manipulated to increase or decrease the distance the lower extension member 1135 occupies with respect to the lower extension member 1155 . Independently of this, threaded actuator 1191 can be used to determine the angle which lower extension member 1155 takes with respect to first frame section 1003 . The angular separation of the lower extension member 1135 occupies with respect to the lower extension member 1155 seen in FIG. 63 is due to the angular position of the second frame section 1005 with respect to the first frame section 1003 . Further separation of the lower extension member 1135 occupies with respect to the lower extension member 1155 can be achieved by actuation of the expanded diameter actuator knob 1195 .
[0305] FIG. 64 is a top view of the frame retractor system 1001 seen in FIGS. 61-63 . Also seen an anchoring structure 1221 held in by a threaded member 1223 . The dashed line portions of the drawing of FIG. 64 illustrate the action in moving the thickened structurally reinforced upper head portion 1131 and lower extension member 1135 along the second frame section 1005 by using the pair of outwardly disposed tongues 1133 within the pair of internally disposed slots 1121 .
[0306] Referring to FIG. 65 , a bottom view of the frame retractor system 1001 seen in FIGS. 61-64 illustrates the nature of the insertion accommodation slots 1137 & 1157 .
[0307] Referring to FIG. 66 a plan view of the frame retractor system 1001 is seen. An additional structural connector 1227 is seen connected to the anchoring structure 1221 .
[0308] Referring to FIG. 67 , a wire retractor 1251 is seen. Wire retractor 1251 has a scissors rear portion 1253 which is shown in a horizontal position and a generally vertical front portion 1255 . As shown, the scissors rear portion may have a ratchet mechanism 1257 for helping to hold the scissors portion 1253 in a closed position which will hold generally vertical front portion 1255 in an open position.
[0309] Generally vertical front portion 1255 includes a pair of relatively thin members 1261 and 1263 , which are connected to scissor arms 1265 and 1267 , respectively. Thin member 1261 , after an angular change 1271 from scissor arm 1265 , includes a somewhat square inward detour as an accommodation portion 1273 . Likewise, thin member 1263 , after an angular change 1275 from scissor arm 1265 , includes a somewhat square inward detour as an accommodation portion 1277 .
[0310] Below and beyond the accommodation portions 1273 and 1277 each of the thin members 1261 and 1263 have a pair of wing extensions 1279 . The wing extensions 1279 limit the ability of the relatively thin members 1261 and 1263 to move past one another, and limit the amount that the accommodation portions 1273 and 1277 actually do move past each other as will be seen.
[0311] Below the wing extensions 1279 the relatively thin members 1261 and 1263 each turn outward and taper to a point 1281 . The point 1281 is used to penetrate muscle and to further stabilize the operational field. Referring to FIG. 68 , the relatively thin members 1261 and 1263 are shown in a position separated from each other, with the accommodation portions 1273 and 1277 being separated. The outwardly directed parts of the accommodation portions 1273 and 1277 are shown in a position to fit within the rounded upper opening of the frame retractor system 1001 . This enables the practitioner to perform lateral retraction while “locking” the wire retractor 1251 into a stable position with respect to the frame retractor system 1001 .
[0312] Referring to FIG. 69 , an isolated view of the generally vertical front portion 1255 illustrates the wire retractor shown superimposed in a crossing pattern to reduce the width profile for entry into the frame retractor system 1001 of FIGS. 61-66 even when the retractor system 1001 is in a position where the lower extension member 1135 is closest to lower extension member 1155 .
[0313] Referring to FIG. 70 , a side view of the frame retractor system 1001 illustrates the position in which the wire retractor 1251 takes within the frame retractor system 1001 . The lower extension member 1135 need only be slightly separated from the lower extension member 1155 to accommodate the wire retractor 1251 . The wire retractor 1251 is simply used to hold back tissue which is already stressed below the bottom of the lower extension members 1135 and 1155 and need only transmit some retention forces to be effective.
[0314] Referring to FIG. 71 illustrates the frame retractor system 1001 and wire retractor 1251 shown with respect to tissue 1285 and which is positioned over deeper tissues 1287 . Note that the pair of wing extensions 1279 are positioned close together. This is the position which the generally vertical front portion 1255 assumes upon insertion into the lower extension members 1135 & 1155 when lower extension members 1135 & 1155 are in close proximity to each other.
[0315] Referring to FIG. 72 , a view illustrating the wire retractor 1251 being opened to a stable open position within the frame retractor system 1001 is seen. The tissue 1285 to the sides are held back even where lower extension members 1135 & 1155 are separated from each other.
[0316] While the present system has been described in terms of a system of instruments and procedures for facilitating the performance of a microscopic lumbar diskectomy procedure, one skilled in the art will realize that the structure and techniques of the present system can be applied to many appliances including any appliance which utilizes the embodiments of the instrumentation of the system or any process which utilizes the steps of the inventive system.
[0317] Although the system of the invention has been derived with reference to particular illustrative embodiments thereof, many changes and modifications of the system 31 may become apparent to those skilled in the art without departing from the spirit and scope of the inventive system. Therefore, included within the patent warranted hereon are all such changes and modifications as may reasonably and properly be included within the scope of this contribution to the art. | A minimal incision maximal access system allows for maximum desirable exposure along with maximum access to the operative field utilizing a minimum incision as small as the METRx and Endius systems. Instead of multiple insertions of dilating tubes the design is a streamlined single entry device to avoid repetitive skin surface entry. The system offers the capability to expand to optimum exposure size for the surgery utilizing hinged bi-hemispherical or oval working tubes applied over an introducer obturator which is controllably dilated to slowly separate muscle tissue. Deeper end working and visualization areas with maximum proximal access and work dimensions are provided to makes the operative procedure safer in application and shorten the surgeons's learning curve because it most closely approximates the ability to use open microdiskectomy techniques. a dual frame system enables full or partial spreading of a working tube set, while an open frame facilitates a four point retraction system. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a U.S. national phase application under 35 U.S.C. §371 of International Appl. No. PCT/US2013/072351, filed on Nov. 27, 2013, which claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Application No. 61/732,252, filed on Nov. 30, 2012, which is hereby incorporated herein by reference in its entirety for all purposes.
FIELD
[0002] The present invention relates to methods of preventing, inhibiting, delaying, and/or mitigating seizures by administration of a steroid, e.g., a neurosteroid, e.g., allopregnanolone.
BACKGROUND
[0003] Steroids, including neurosteroids (e.g., allopregnanolone) are highly insoluble in aqueous solution. Various approaches are used to enhance aqueous dissolution, including the use of cyclodextrin solutions. However, even with cyclodextrin as a solvation aid, solubility is not sufficient to permit systemic delivery for the treatment of medical conditions.
SUMMARY
[0004] In one aspect, methods of preventing, treating, reducing, and/or mitigating one or more symptoms associated with and/or caused by traumatic brain injury, Alzheimer's disease, epilepsy, anxiety, fragile X syndrome, post-traumatic stress disorder, lysosomal storage disorders (Niemann-Pick type C disease), depression (including post-partum depression), premenstrual dysphoric disorder, alcohol craving, and smoking cessation in a subject in need thereof are provided. In some embodiments, the methods comprise administering to the subject a steroid.
[0005] In another aspect, methods of preventing, treating, reducing, and/or mitigating symptoms associated with and/or caused by epilepsy, in a subject in need thereof are provided. In some embodiments, the methods comprise administering to the subject a steroid.
[0006] In a further aspect, methods of accelerating the termination or abortion of an impending seizure in a subject in need thereof are provided. In some embodiments, the methods comprise administering to the subject a steroid.
[0007] With respect to embodiments of the methods, in some embodiments, the steroid is a neurosteroid. In some embodiments, the neurosteroid is selected from the group consisting of allopregnanolone, allotetrahydrodeoxycorticosterone, ganaxolone, alphaxolone, alphadolone, hydroxydione, minaxolone, and Althesin. In some embodiments, the neurosteroid is allopregnanolone. In some embodiments, the steroid is formulated in a cyclodextrin. In various embodiments, the steroid is formulated in hydroxypropyl-beta-cyclodextrin or sulfobutylether-beta-cyclodextrin sodium salt. In some embodiments, the subject is experiencing aura. In some embodiments, the subject has been warned of an impending seizure. In some embodiments, the subject is experiencing a seizure. In some embodiments, the subject has status epilepticus. In some embodiments, the subject has myoclonic epilepsy. In some embodiments, the subject suffers from seizure clusters. In some embodiments, the seizure is a tonic seizure. In some embodiments, the seizure is a clonic seizure. In some embodiments, the subject is a human. In some embodiments, the steroid is administered intramuscularly, intravenously or subcutaneously. In some embodiments, the methods entail treating, reducing, and/or mitigating symptoms associated with and/or caused by epilepsy by intramuscularly (i.m.), subcutaneously (s.c.) or intravenously (i.v.) administering allopregnanolone formulated in a sulfobutylether-beta-cyclodextrin sodium salt. In some embodiments, the epilepsy is status epilepticus. In some embodiments, the steroid or neurosteroid (e.g., allopregnanolone) is administered at a dose in the range of about 0.25 mg/kg to about 15 mg/kg, e.g., about 0.25, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 mg/kg. In some embodiments, the steroid or neurosteroid (e.g., allopregnanolone) is self-administered by the subject. In some embodiments, the steroid or neurosteroid (e.g., allopregnanolone) is administered by a caregiver who is not the subject.
[0008] In a further aspect, compositions comprising or consisting essentially of a steroid and a cyclodextrin are provided. In some embodiments, the steroid is a neurosteroid. In some embodiments, the neurosteroid is selected from the group consisting of allopregnanolone, allotetrahydrodeoxycorticosterone, ganaxolone, alphaxolone, alphadolone, hydroxydione, minaxolone, and Althesin. In some embodiments, the steroid is allopregnanolone. In some embodiments, the cyclodextrin is hydroxypropyl-beta-cyclodextrin, sulfobutylether-beta-cyclodextrin sodium salt, or mixture thereof. In some embodiments, the composition comprises allopregnanolone and sulfobutylether-beta-cyclodextrin sodium salt.
[0009] In some embodiments, the steroid or neurosteroid (e.g., allopregnanolone) is administered or formulated for administration via an inhaler. In some embodiments, the steroid or neurosteroid (e.g., allopregnanolone) is nebulized or aerosolized. In some embodiments, the steroid or neurosteroid (e.g., allopregnanolone) is nebulized or aerosolized without heating. In some embodiments, the nebulized or aerosolized steroid or neurosteroid (e.g., allopregnanolone) particles have a mass median aerodynamic diameter (“MMAD”) of about 5 μm or smaller. In some embodiments, the nebulized or aerosolized steroid or neurosteroid (e.g., allopregnanolone) particles have a mass median aerodynamic diameter (“MMAD”) of about 2-3 μm. In some embodiments, the steroid or neurosteroid (e.g., allopregnanolone) is delivered to the distal alveoli.
DEFINITIONS
[0010] As used herein, “administering” refers to local and systemic administration, e.g., including enteral, parenteral, pulmonary, and topical/transdermal administration. Routes of administration for steroid or neurosteroids (e.g., allopregnanolone) that find use in the methods described herein include, e.g., oral (per os (P.O.)) administration, nasal, inhalation or intrapulmonary administration, administration as a suppository, topical contact, transdermal delivery (e.g., via a transdermal patch), intrathecal (IT) administration, intravenous (“iv”) administration, intraperitoneal (“ip”) administration, intramuscular (“im”) administration, or subcutaneous (“sc”) administration, or the implantation of a slow-release device e.g., a mini-osmotic pump, a depot formulation, etc., to a subject. Administration can be by any route including parenteral and transmucosal (e.g., oral, nasal, vaginal, rectal, or transdermal). Parenteral administration includes, e.g., intravenous, intramuscular, intra-arterial, intradermal, subcutaneous, intraperitoneal, intraventricular, ionophoretic and intracranial. Other modes of delivery include, but are not limited to, the use of liposomal formulations, intravenous infusion, transdermal patches, etc.
[0011] The terms “systemic administration” and “systemically administered” refer to a method of administering a compound or composition to a mammal so that the compound or composition is delivered to sites in the body, including the targeted site of pharmaceutical action, via the circulatory system. Systemic administration includes, but is not limited to, oral, intranasal, rectal and parenteral (e.g., other than through the alimentary tract, such as intramuscular, intravenous, intra-arterial, transdermal and subcutaneous) administration.
[0012] The term “co-administration” refers to the presence of both active agents in the blood at the same time. Active agents that are co-administered can be delivered concurrently (i.e., at the same time) or sequentially.
[0013] The phrase “cause to be administered” refers to the actions taken by a medical professional (e.g., a physician), or a person controlling medical care of a subject, that control and/or permit the administration of the steroid or neurosteroid (e.g., allopregnanolone) to the subject. Causing to be administered can involve diagnosis and/or determination of an appropriate therapeutic or prophylactic regimen, and/or prescribing particular steroid or neurosteroid (e.g., allopregnanolone) for a subject. Such prescribing can include, for example, drafting a prescription form, annotating a medical record, and the like.
[0014] The term “effective amount” or “pharmaceutically effective amount” refer to the amount and/or dosage, and/or dosage regime of one or more steroid or neurosteroid (e.g., allopregnanolone) necessary to bring about the desired result e.g., an amount sufficient prevent, abort or terminate a seizure.
[0015] As used herein, the terms “treating” and “treatment” refer to delaying the onset of, retarding or reversing the progress of, reducing the severity of, or alleviating or preventing either the disease or condition to which the term applies, or one or more symptoms of such disease or condition.
[0016] The terms “reduce,” “inhibit,” “relieve,” “alleviate” refer to the detectable decrease in the frequency, severity and/or duration of seizures. A reduction in the frequency, severity and/or duration of seizures can be measured by self-assessment (e.g., by reporting of the patient) or by a trained clinical observer. Determination of a reduction of the frequency, severity and/or duration of seizures can be made by comparing patient status before and after treatment.
[0017] The term “mitigating” refers to reduction or elimination of one or more symptoms of that pathology or disease, and/or a reduction in the rate or delay of onset or severity of one or more symptoms of that pathology or disease (e.g., seizures), and/or the prevention of that pathology or disease.
[0018] As used herein, the phrase “consisting essentially of” refers to the genera or species of active pharmaceutical agents (e.g., neurosteroid, e.g., allopregnanolone) and excipient (e.g., hydroxypropyl-beta-cyclodextrin or Captisol (sulfobutylether-beta-cyclodextrin sodium salt)) included in a method or composition. In various embodiments, other unmentioned or unrecited active ingredients and inactive are expressly excluded. In various embodiments, additives (e.g., surfactants, acids (organic or fatty), alcohols, esters, co-solvents, solubilizers, lipids, polymers, glycols) are expressly excluded.
[0019] The terms “subject,” “individual,” and “patient” interchangeably refer to a mammal, preferably a human or a non-human primate, but also domesticated mammals (e.g., canine or feline), laboratory mammals (e.g., mouse, rat, rabbit, hamster, guinea pig) and agricultural mammals (e.g., equine, bovine, porcine, ovine). In various embodiments, the subject can be a human (e.g., adult male, adult female, adolescent male, adolescent female, male child, female child) under the care of a physician or other healthworker in a hospital, psychiatric care facility, as an outpatient, or other clinical context. In certain embodiments the subject may not be under the care or prescription of a physician or other healthworker.
[0020] The term “neuroactive steroid” or “neurosteroid” refers to steroid compounds that rapidly alter neuronal excitability through interaction with neurotransmitter-gated ion channels. Neurosteroids act as allosteric modulators of neurotransmitter receptors, such as GABA A , NMDA, and sigma receptors. Neurosteroids find use as sedatives for the purpose of general anaesthesia for carrying out surgical procedures, and in the treatment of epilepsy and traumatic brain injury. Illustrative neurosteroids include, e.g., allopregnanolone, Ganaxolone, alphaxolone, alphadolone, hydroxydione, minaxolone, and Althesin (a mixture of alphaxolone and alphadolone).
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 illustrates a time course for protection by allopregnanolone (5α,3α-P) administered i.v. at a doses of 1.5 and 0.5 mg/kg respectively in the 6-Hz electrical-stimulation (32 mA, 3 s) model. The interval between the steroid injection and the electrical stimulus is plotted on the abscissa and the percentage of animals protected against seizures is plotted on the ordinate. Each point represents eight mice.
[0022] FIG. 2 illustrates a time course for protection by allopregnanolone (5α,3α-P) administered i.m. at a doses of 6, 3, 1.5 mg/kg in the 6-Hz electrical stimulation (32 mA, 3 s) model. The interval between the steroid injection and the electrical stimulus is plotted on the abscissa and the percentage of animals protected against seizures is plotted on the ordinate. Each point represents at least eight mice.
[0023] FIG. 3 illustrates a time course for protection by allopregnanolone (5α,3α-P) administered s.c. at a doses of 6 and 1.5 mg/kg in the 6-Hz electrical stimulation (32 mA, 3 s) model. The interval between the steroid injection and the electrical stimulus is plotted on the abscissa and the percentage of animals protected against seizures is plotted on the ordinate. Each point represents eight mice.
[0024] FIG. 4 illustrates a time course for protection by allopregnanolone (5α,3α-P) administered p.o. at a dose of 300 and 200 mg/kg (double volume of 150 mg/kg and 100 mg/kg suspended/diluted in Canola oil) in the 6-Hz electrical-stimulation (32 mA, 3 s) model. The interval between the steroid injection and the electrical stimulus is plotted on the abscissa and the percentage of animals protected against seizures is plotted on the ordinate. Each point represents at seven to eight mice.
[0025] FIG. 5 illustrates the effect of i.v. administration of allopregnanolone (5α,3α-P) (0.1-1.5 mg/kg) on the onset of myoclonic jerk, generalized clonus, and tonic extension in response to PTZ (80 mg/kg, i.p.) injection in mice. 5α,3α-P was administered i.v. 1 min before PTZ injection. Bars indicate mean S.E.M. of values from eight mice. p<0.05 compared with vehicle control group (ANOVA followed by Dunnett's test).
[0026] FIG. 6 illustrates the effect of i.v. administration of allopregnanolone (5α,3α-P) (0.1-1.5 mg/kg) on the onset of myoclonic jerk, generalized clonus, and tonic extension in response to PTZ (80 mg/kg, i.p.) injection in mice. 5α,3α-P was administered i.v. 2 min before PTZ injection. Bars indicate mean S.E.M. of values from eight mice. p<0.05 compared with vehicle control group (ANOVA followed by Dunnett's test).
[0027] FIG. 7 illustrates the effect of i.v. administration of allopregnanolone (5α,3α-P) (0.25-1.5 mg/kg) on the onset of myoclonic jerk, generalized clonus, and tonic extension in response to PTZ (80 mg/kg, i.p.) injection in mice. 5α,3α-P was administered i.v. 30 min before PTZ injection. Bars indicate mean S.E.M. of values from eight mice. p<0.05 compared with vehicle control group (ANOVA followed by Dunnett's test).
[0028] FIG. 8 illustrates the effect of i.m. administration of allopregnanolone (5α,3α-P) (0.25-1.5 mg/kg) on the onset of myoclonic jerk, generalized clonus, and tonic extension in response to PTZ (80 mg/kg, i.p.) injection in mice. 5α,3α-P was administered i.m. 2 min before PTZ injection. Bars indicate mean S.E.M. of values from at least seven mice. p<0.05 compared with vehicle control group (ANOVA followed by Dunnett's test).
[0029] FIG. 9 illustrates the effect of i.m. administration of allopregnanolone (5α,3α-P) (0.25-1.5 mg/kg) on the onset of myoclonic jerk, generalized clonus, and tonic extension in response to PTZ (80 mg/kg, i.p.) injection in mice. 5α,3α-P was administered i.m. 30 min before PTZ injection. Bars indicate mean S.E.M. of values from eight mice. p<0.05 compared with vehicle control group (ANOVA followed by Dunnett's test).
[0030] FIG. 10 illustrates a Time-concentration profile for plasma allopregnanolone (5α,3α-P) after single i.v. injection in rats. Rats bearing indwelling jugular catheters received single i.v. injection of 5α,3α-P or vehicle and serial blood samples were withdrawn at 1, 2, 10, 15, 30, 60 and 120 min after injection. Plasma was assayed for 5α,3α-P by LC-MS. Each point represents at least 4 animals.
DETAILED DESCRIPTION
[0031] 1. Introduction
[0032] Treatment of status epilepicus requires rapid administration of anti-seizure agents, which are typically delivered either by the intravenous (IV) or intramuscular (IM) routes. Allopregnanolone (3α-hydroxy-5α-pregnan-20-one; 5α,3α-P), an endogenous progesterone-derived steroid that is a positive allosteric modulator of GABA A receptors, is a powerful anti-seizure agent with potential in the treatment of status epilepticus. The present study determines and demonstrates the dosing of allopregnanolone to protect against seizures when delivered intravenously (i.v.), intramuscularly (i.m.), subcutaneously (s.c.) or orally (p.o.).
[0033] 2. Subjects Who Can Benefit
[0034] In various embodiments, the subject has a condition that can be treated or mitigated by administration of a neurosteroid, e.g., allopregnanolone. Allopregnanolone has many medical uses, including the treatment, reduction, and/or mitigation of symptoms associated with and/or caused by traumatic brain injury, Alzheimer's disease, epilepsy, anxiety, fragile X syndrome, post-traumatic stress disorder, lysosomal storage disorders (Niemann-Pick type C disease), depression (including post-partum depression), premenstrual dysphoric disorder, alcohol craving, and smoking cessation. The subject may or may not be exhibiting symptoms.
[0035] Accordingly, the invention also contemplates methods of treating, reducing, and/or mitigating symptoms associated with and/or caused by traumatic brain injury, Alzheimer's disease, epilepsy, anxiety, fragile X syndrome, post-traumatic stress disorder, lysosomal storage disorders (Niemann-Pick type C disease), depression (including post-partum depression), premenstrual dysphoric disorder, alcohol craving, and smoking cessation by administration of a steroid or neurosteroid (e.g., allopregnanolone) dissolved or suspended in a vehicle suitable for systemic administration (e.g., intramuscular, intravenous, subcutaneous), as described herein.
[0036] In some embodiments, the subject has epilepsy, has a history of suffering from epileptic seizures or is suffering from epileptic seizures. In various embodiments, the patient may be experiencing an electrographic or behavioral seizure or may be experiencing a seizure aura, which itself is a localized seizure that may spread and become a full blown behavioral seizure. For example, the subject may be experiencing aura that alerts of the impending onset of a seizure or seizure cluster.
[0037] Alternatively, the subject may be using a seizure prediction device that alerts of the impending onset of a seizure or seizure cluster. Implantable seizure prediction devices are known in the art and described, e.g., in D'Alessandro, et al., IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING, VOL. 50, NO. 5, May 2003, and U.S. Patent Publication Nos. 2010/0198098, 2010/0168603, 2009/0062682, and 2008/0243022.
[0038] The subject may have a personal or familial history of any of the epileptic conditions described herein. The subject may have been diagnosed as having any of the epileptic conditions described herein. In some embodiments, the subject has or is at risk of suffering a myoclonic seizure or myoclonic epilepsy, e.g., juvenile myoclonic epilepsy. The PTZ seizure model demonstrated herein is predictive of utility and/or activity in counteracting myoclonic seizures or myoclonic epilepsy in humans.
[0039] In various embodiments, the subject may be at risk of exposure to or may have been exposed to a nerve agent or a pesticide that can cause seizures. Illustrative nerve agents that can cause seizures include, e.g., organophosphorus nerve agents, e.g., tabun, sarin, soman, GF, VR and/or VX. Illustrative pesticides that can cause seizures include, e.g., organophosphate pesticides (e.g., Acephate (Orthene), Azinphos-methyl (Gusathion, Guthion), Bensulide (Betasan, Lescosan), Bomyl (Swat), Bromophos (Nexion), Bromophos-ethyl (Nexagan), Cadusafos (Apache, Ebufos, Rugby), Carbophenothion (Trithion), Chlorethoxyfos (Fortress), Chlorfenvinphos (Apachlor, Birlane), Chlormephos (Dotan), Chlorphoxim (Baythion-C), Chlorpyrifos (Brodan, Dursban, Lorsban), Chlorthiophos (Celathion), Coumaphos (Asuntol, Co-Ral), Crotoxyphos (Ciodrin, Cypona), Crufomate (Ruelene), Cyanofenphos (Surecide), Cyanophos (Cyanox), Cythioate (Cyflee, Proban), DEF (De-Green), E-Z-Off D), Demeton (Systox), Demeton-S-methyl (Duratox, Metasystoxl), Dialifor (Torak), Diazinon, Dichlorofenthion, (VC-13 Nemacide), Dichlorvos (DDVP, Vapona), Dicrotophos (Bidrin), Dimefos (Hanane, Pestox XIV), Dimethoate (Cygon, DeFend), Dioxathion (Delnav), Disulfoton (Disyston), Ditalimfos, Edifenphos, Endothion, EPBP (S-seven), EPN, Ethion (Ethanox), Ethoprop (Mocap), Ethyl parathion (E605, Parathion, thiophos), Etrimfos (Ekamet), Famphur (Bash, Bo-Ana, Famfos), Fenamiphos (Nemacur), Fenitrothion (Accothion, Agrothion, Sumithion), Fenophosphon (Agritox, trichloronate), Fensulfothion (Dasanit), Fenthion (Baytex, Entex, Tiguvon), Fonofos (Dyfonate, N-2790), Formothion (Anthio), Fosthietan (Nem-A-Tak), Heptenophos (Hostaquick), Hiometon (Ekatin), Hosalone (Zolone), IBP (Kitazin), Iodofenphos (Nuvanol-N), Isazofos (Brace, Miral, Triumph), Isofenphos (Amaze, Oftanol), Isoxathion (E-48, Karphos), Leptophos (Phosvel), Malathion (Cythion), Mephosfolan (Cytrolane), Merphos (Easy Off-D, Folex), Methamidophos (Monitor), Methidathion (Supracide, Ultracide), Methyl parathion (E601, Penncap-M), Methyl trithion, Mevinphos (Duraphos, Phosdrin), Mipafox (Isopestox, Pestox XV), Monocrotophos (Azodrin), Naled (Dibrome), Oxydemeton-methyl (Metasystox-R), Oxydeprofos (Metasystox-S), Phencapton (G 28029), Phenthoate (Dimephenthoate, Phenthoate), Phorate (Rampart, Thimet), Phosalone (Azofene, Zolone), Phosfolan (Cylan, Cyolane), Phosmet (Imidan, Prolate), Phosphamidon (Dimecron), Phostebupirim (Aztec), Phoxim (Baythion), Pirimiphos-ethyl (Primicid), Pirimiphos-methyl (Actellic), Profenofos (Curacron), Propetamphos (Safrotin), Propyl thiopyrophosphate (Aspon), Prothoate (Fac), Pyrazophos (Afugan, Curamil), Pyridaphenthion (Ofunack), Quinalphos (Bayrusil), Ronnel (Fenchlorphos, Korlan), Schradan (OMPA), Sulfotep (Bladafum, Dithione, Thiotepp), Sulprofos (Bolstar, Helothion), Temephos (Abate, Abathion), Terbufos (Contraven, Counter), Tetrachlorvinphos (Gardona, Rabon), Tetraethyl pyrophosphate (TEPP), Triazophos (Hostathion), and Trichlorfon (Dipterex, Dylox, Neguvon, Proxol).
[0040] 3. Steroids
[0041] The compositions generally comprise or consist essentially of a steroid, e.g., a neurosteroid, suspended or dissolved in vehicle appropriate for systemic administration, e.g., a cyclodextrin, e.g., hydroxypropyl-beta-cyclodextrin or sulfobutylether-beta-cyclodextrin sodium salt, or mixtures thereof.
[0042] In various embodiments the neurosteroid is allopregnanolone (ALP). Allopregnanolone, also known as 3α-hydroxy-5α-pregnan-20-one or 3α,5α-tetrahydroprogesterone, IUPAC name 1-(3-Hydroxy-10,13-dimethyl-2,3,4,5,6,7,8,9,11,12,14,15,16,17-tetradecahydro-1H-cyclopenta[a]phenanthren-17-yl)ethanone, and referenced as CAS number 516-54-1, is a prototypic neurosteroid present in the blood and also the brain. It is a metabolite of progesterone and modulator of GABA A receptors. While allopregnanolone, like other GABA A receptor active neurosteroids such as allotetrahydrodeoxycorticosterone (3α,21-dihydroxy-5α-pregnan-20-one; THDOC), positively modulates all GABA A receptor isoforms, those isoforms containing δ-subunits exhibit greater magnitude potentiation. Allopregnanolone has pharmacological properties similar to other positive modulators of GABA A receptors, including anxiolytic and anticonvulsant activity. Allopregnanolone is neuroprotective in many animal models of neurodegenerative conditions, including, e.g., Alzheimer's disease (Wang et al., Proc Natl Acad Sci USA . 2010 Apr. 6; 107(14):6498-503), cerebral edema (Limmroth et al., Br J Pharmacol . 1996 January; 117(1):99-104) and traumatic brain injury (He et al., Restor Neurol Neurosci . 2004; 22(1):19-31; and He, et al., Exp Neurol . 2004 October; 189(2):404-12), Mood disorders (Robichaud and Debonnel, Int J Neuropsychopharmacol . 2006 April; 9(2):191-200), Niemann-Pick type C disease (Griffin et al., Nat Med . 2004 July; 10(7):704-11) and acts as an anticonvulsant against chemically induced seizures, including the pentylenetetrazol (PTZ) model (Kokate et al., J Pharmacol Exp Ther . 1994 September; 270(3):1223-9). The chemical structure of allopregnanolone is depicted below in Formula I:
[0000]
[0043] In various embodiments, the compositions comprise a sulfate, salt, hemisuccinate, nitrosylated, derivative or congener of allopregnanolone.
[0044] Other neurosteroids that can be formulated in vehicle suitable for systemic administration, include without limitation allotetrahydrodeoxycorticosterone (3α,21-dihydroxy-5α-pregnan-20-one; THDOC), 3α,21-dihydroxy-5b-pregnan-20-one, pregnanolone (3α-hydroxy-5β-pregnan-20-one), Ganaxolone (INN, also known as CCD-1042; IUPAC name (3α,5α)-3-hydroxy-5-methylpregnan-20-one; 1-R3R,5S,8R,9S,10S,13S,14S,17S)-3-hydroxy-3,10,13-trimethyl-1,2,4,5,6,7,8,9,11,12,14,15,16,17-tetradecahydrocyclopenta[a]phenanthren-17-yl]ethanone), alphaxolone, alphadolone, hydroxydione, minaxolone, and Althesin (a mixture of alphaxolone, alphadolone, tetrahydrodeoxycorticosterone, pregnenolone, dehydroepiandrosterone (DHEA), 7-substituted benz[e]indene-3-carbonitriles (see, e.g., Hu, et al., J Med Chem . (1993) 36(24):3956-67); 7-(2-hydroxyethyl)benz[e]indene analogues (see, e.g., Han, et al., J Med Chem . (1995) 38(22):4548-56); 3 alpha-hydroxy-5 alpha-pregnan-20-one and 3 alpha-hydroxy-5 beta-pregnan-20-one analogues (see, e.g., Han, et al., J Med Chem . (1996) 39(21):4218-32); enantiomers of dehydroepiandrosterone sulfate, pregnenolone sulfate, and (3alpha,5beta)-3-hydroxypregnan-20-one sulfate (see, e.g., Nilsson, et al., J Med Chem . (1998) 41(14):2604-13); 13,24-cyclo-18,21-dinorcholane analogues (see, e.g., Jiang, et al., J Med Chem . (2003) 46(25):5334-48); N-acylated 17a-aza-D-homosteroid analogues (see, e.g., Covey, et al., J Med Chem . (2000) 43(17):3201-4); 5 beta-methyl-3-ketosteroid analogues (see, e.g., Zeng, et al., J Org Chem . (2000) 65(7):2264-6); 18-norandrostan-17-one analogues (see, e.g., Jiang, et al., J Org Chem . (2000) 65(11):3555-7); (3alpha,5alpha)- and (3alpha,5beta)-3-hydroxypregnan-20-one analogs (see, e.g., Zeng, et al., J Med Chem . (2005) 48(8):3051-9); benz[f]indenes (see, e.g., Scaglione, et al., J Med Chem . (2006) 49(15):4595-605); enantiomers of androgens (see, e.g., Katona, et al., Eur J Med Chem . (2008) 43(1):107-13); cyclopenta[b]phenanthrenes and cyclopenta[b]anthracenes (see, e.g., Scaglione, et al., J Med Chem . (2008) 51(5):1309-18); 2beta-hydroxygonane derivatives (see, e.g., Wang, et al., Tetrahedron (2007) 63(33):7977-7984); Δ16-alphaxalone and corresponding 17-carbonitrile analogues (see, e.g., Bandyopadhyaya, et al., Bioorg Med Chem Lett . (2010) 20(22):6680-4); Δ(16) and Δ(17(20)) analogues of Δ(16)-alphaxalone (see, e.g., Stastna, et al., J Med Chem . (2011) 54(11):3926-34); neurosteroid analogs developed by CoCensys (now Purdue Neuroscience) (e.g., CCD-3693, Co2-6749 (a.k.a., GMA-839 and WAY-141839); neurosteroid analogs described in U.S. Pat. No. 7,781,421 and in PCT Patent Publications WO 2008/157460; WO 1993/003732; WO 1993/018053; WO 1994/027608; WO 1995/021617; WO 1996/016076; WO 1996/040043, as well as salts, hemisuccinates, nitrosylated, sulfates and derivatives thereof.
[0045] In various embodiments, the steroid or neurosteroid is not a sex hormone. In various embodiments, the steroid or neurosteroid is not progesterone.
[0046] As appropriate, the steroid or neurosteroid (e.g., allopregnanolone) may or may not be micronized. As appropriate, the steroid or neurosteroid (e.g., allopregnanolone) may or may not be enclosed in microspheres in suspension in the oil.
[0047] 4. Formulation and Administration
[0048] In varying embodiments, the steroid and/or an analog thereof can be administered systemically, e.g., intramuscularly (IM), or depo-IM, subcutaneously (SQ), and depo-SQ), as appropriate or desired. In varying embodiments, the dosage form is selected to facilitate delivery to the brain (e.g., passage through the blood brain barrier). In this context it is noted that the steroids or neurosteroids (e.g., allopregnanolone) described herein can be readily delivered to the brain. Dosage forms known to those of skill in the art are suitable for delivery of the steroid.
[0049] Compositions are provided that contain therapeutically effective amounts of the steroid or neurosteroid (e.g., allopregnanolone). The steroids or neurosteroids (e.g., allopregnanolone) are preferably formulated into suitable pharmaceutical preparations such as tablets, capsules, or elixirs for oral administration or in sterile solutions or suspensions for parenteral administration. Typically the steroids or neurosteroids (e.g., allopregnanolone) described above are formulated into pharmaceutical compositions using techniques and procedures well known in the art.
[0050] These steroids or neurosteroids (e.g., allopregnanolone) or analogs thereof can be administered in the “native” form or, if desired, in the form of salts, esters, amides, prodrugs, derivatives, and the like, provided the salt, ester, amide, prodrug or derivative is suitable pharmacologically effective, e.g., effective in the present method(s). Salts, esters, amides, prodrugs and other derivatives of the active agents can be prepared using standard procedures known to those skilled in the art of synthetic organic chemistry and described, for example, by March (1992) Advanced Organic Chemistry; Reactions, Mechanisms and Structure , 4th Ed. N.Y. Wiley-Interscience.
[0051] Methods of formulating such derivatives are known to those of skill in the art. For example, the disulfide salts of a number of delivery agents are described in PCT Publication WO 2000/059863 which is incorporated herein by reference. Similarly, acid salts of therapeutic peptides, peptoids, or other mimetics, and can be prepared from the free base using conventional methodology that typically involves reaction with a suitable acid. Generally, the base form of the drug is dissolved in a polar organic solvent such as methanol or ethanol and the acid is added thereto. The resulting salt either precipitates or can be brought out of solution by addition of a less polar solvent. Suitable acids for preparing acid addition salts include, but are not limited to both organic acids, e.g., acetic acid, propionic acid, glycolic acid, pyruvic acid, oxalic acid, malic acid, malonic acid, succinic acid, maleic acid, fumaric acid, tartaric acid, citric acid, benzoic acid, cinnamic acid, mandelic acid, methanesulfonic acid, ethanesulfonic acid, p-toluenesulfonic acid, salicylic acid, orotic acid, and the like, as well as inorganic acids, e.g., hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid, and the like. An acid addition salt can be reconverted to the free base by treatment with a suitable base. Certain particularly preferred acid addition salts of the active agents herein include halide salts, such as may be prepared using hydrochloric or hydrobromic acids. Conversely, preparation of basic salts of the active agents of this invention are prepared in a similar manner using a pharmaceutically acceptable base such as sodium hydroxide, potassium hydroxide, ammonium hydroxide, calcium hydroxide, trimethylamine, or the like. In certain embodiments basic salts include alkali metal salts, e.g., the sodium salt, and copper salts.
[0052] For the preparation of salt forms of basic drugs, the pKa of the counterion is preferably at least about 2 pH lower than the pKa of the drug. Similarly, for the preparation of salt forms of acidic drugs, the pKa of the counterion is preferably at least about 2 pH higher than the pKa of the drug. This permits the counterion to bring the solution's pH to a level lower than the pHmax to reach the salt plateau, at which the solubility of salt prevails over the solubility of free acid or base. The generalized rule of difference in pKa units of the ionizable group in the active pharmaceutical ingredient (API) and in the acid or base is meant to make the proton transfer energetically favorable. When the pKa of the API and counterion are not significantly different, a solid complex may form but may rapidly disproportionate (e.g., break down into the individual entities of drug and counterion) in an aqueous environment.
[0053] Preferably, the counterion is a pharmaceutically acceptable counterion. Suitable anionic salt forms include, but are not limited to acetate, benzoate, benzylate, bitartrate, bromide, carbonate, chloride, citrate, edetate, edisylate, estolate, fumarate, gluceptate, gluconate, hydrobromide, hydrochloride, iodide, lactate, lactobionate, malate, maleate, mandelate, mesylate, methyl bromide, methyl sulfate, mucate, napsylate, nitrate, pamoate (embonate), phosphate and diphosphate, salicylate and disalicylate, stearate, succinate, sulfate, tartrate, tosylate, triethiodide, valerate, and the like, while suitable cationic salt forms include, but are not limited to aluminum, benzathine, calcium, ethylene diamine, lysine, magnesium, meglumine, potassium, procaine, sodium, tromethamine, zinc, and the like.
[0054] In various embodiments preparation of esters typically involves functionalization of hydroxyl and/or carboxyl groups that are present within the molecular structure of the active agent. In certain embodiments, the esters are typically acyl-substituted derivatives of free alcohol groups, e.g., moieties that are derived from carboxylic acids of the formula RCOOH where R is alkyl, and preferably is lower alkyl. Esters can be reconverted to the free acids, if desired, by using conventional hydrogenolysis or hydrolysis procedures.
[0055] Amides can also be prepared using techniques known to those skilled in the art or described in the pertinent literature. For example, amides may be prepared from esters, using suitable amine reactants, or they may be prepared from an anhydride or an acid chloride by reaction with ammonia or a lower alkyl amine.
[0056] Determination of an effective amount for administration in a single dosage is well within the capability of those skilled in the art, especially in light of the detailed disclosure provided herein. Generally, an efficacious or effective amount of the steroid or neurosteroid (e.g., allopregnanolone) is determined by first administering a low dose or small amount of the agent and then incrementally increasing the administered dose or dosages, adding a second or third medication as needed, until a desired effect of is observed in the treated subject with minimal or no toxic side effects. Applicable methods for determining an appropriate dose and dosing schedule for administration of a combination of the present invention are described, for example, in Brunton, et al., Goodman and Gilman's The Pharmacological Basis of Therapeutics, 12th Edition, 2010, McGraw-Hill Professional; in a Physicians' Desk Reference (PDR), 66 th Edition, 2012; in Loyd, et al., Remington: The Science and Practice of Pharmacy, 22 st Ed., 2012, Pharmaceutical Press; in Martindale: The Complete Drug Reference , Sweetman, 2005, London: Pharmaceutical Press., and in Martindale, Martindale: The Extra Pharmacopoeia, 31st Edition., 1996, Amer Pharmaceutical Assn, each of which are hereby incorporated herein by reference. In various embodiments, the compositions are formulated, e.g., for oral administration, at a dose in the range of about 5 mg/kg to about 250 mg/kg of the steroid or neurosteroid (e.g., allopregnanolone), e.g., about 5 mg/kg, 10 mg/kg, 15 mg/kg, 20 mg/kg, 25 mg/kg, 30 mg/kg, 35 mg/kg, 40 mg/kg, 45 mg/kg, 50 mg/kg, 75 mg/kg, 100 mg/kg, 125 mg/kg, 150 mg/kg, 200 mg/kg, or 250 mg/kg.
[0057] About 1 to 1000 mg of a steroid or neurosteroid (e.g., allopregnanolone), or a physiologically acceptable salt or ester is compounded with a physiologically acceptable vehicle, carrier, excipient, binder, preservative, stabilizer, flavor, etc., in a unit dosage form as called for by accepted pharmaceutical practice. The amount of active substance in those compositions or preparations is such that a suitable dosage in the range indicated is obtained. The compositions are preferably formulated in a unit dosage form, each dosage containing from about 1-1000 mg, 2-800 mg, 5-500 mg, 10-400 mg, 50-200 mg, e.g., about 5 mg, 10 mg, 15 mg, 20 mg, 25 mg, 30 mg, 35 mg, 40 mg, 45 mg, 50 mg, 60 mg, 70 mg, 80 mg, 90 mg, 100 mg, 200 mg, 300 mg, 400 mg, 500 mg, 600 mg, 700 mg, 800 mg, 900 mg or 1000 mg of the active ingredient. In varying embodiments, the steroid or neurosteroid (e.g., allopregnanolone) is administered systemically (e.g., intramuscularly, intravenously, subcutaneously) at a dose in the range of about 0.25 mg/kg to about 15 mg/kg, e.g., about 0.25 mg/kg to about 15 mg/kg, e.g., about 0.25, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 mg/kg. The term “unit dosage from” refers to physically discrete units suitable as unitary dosages for human subjects and other mammals, each unit containing a predetermined quantity of active material calculated to produce the desired therapeutic effect, in association with a suitable pharmaceutical excipient.
[0058] In varying embodiments, the steroids or neurosteroids (e.g., allopregnanolone) are formulated for intrapulmonary administration. In various embodiments, the steroids or neurosteroids (e.g., allopregnanolone) are formulated for delivery via an inhaler.
[0059] In various embodiments, the steroids or neurosteroids (e.g., allopregnanolone) are nebulized. Methods and systems for intrapulmonary delivery of steroids or neurosteroids (e.g., allopregnanolone) are known in the art and find use. Illustrative systems for aerosol delivery of steroids or neurosteroids (e.g., allopregnanolone) by inhalation are described, e.g., in U.S. Pat. Nos. 5,497,763; 5,660,166; 7,060,255; and 7,540,286; and U.S. Patent Publication Nos. 2003/0032638; and 2006/0052428, each of which are hereby incorporated herein by reference in their entirety for all purposes. Preferably, the steroids or neurosteroids (e.g., allopregnanolone) are nebulized without the input of heat.
[0060] For administration of the nebulized and/or aerosolized steroids or neurosteroids (e.g., allopregnanolone), the size of the aerosol particulates can be within a range appropriate for intrapulmonary delivery, particularly delivery to the distal alveoli. In various embodiments, the aerosol particulates have a mass median aerodynamic diameter (“MMAD”) of less than about 5 μm, 4 μm, 3 μm, for example, ranging from about 1 μm to about 3 μm, e.g., from about 2 μm to about 3 μm, e.g., ranging from about 0.01 μm to about 0.10 μm. Aerosols characterized by a MMAD ranging from about 1 μm to about 3 μm can deposit on alveoli walls through gravitational settling and can be absorbed into the systemic circulation, while aerosols characterized by a MMAD ranging from about 0.01 μm to 0.10 μm can also be deposited on the alveoli walls through diffusion. Aerosols characterized by a MMAD ranging from about 0.15 μm to about 1 μm are generally exhaled. Thus, in various embodiments, aerosol particulates can have a MMAD ranging from 0.01 μm to about 5 μm, for example, ranging from about 0.05 μm to about 3 μm, for example, ranging from about 1 μm to about 3 μm, for example, ranging from about 0.01 μm to about 0.1 μm. The nebulized and/or aerosolized steroids or neurosteroids (e.g., allopregnanolone) can be delivered to the distal alveoli, allowing for rapid absorption and efficacy.
[0061] In various embodiments, the steroids or neurosteroids (e.g., allopregnanolone) is formulated in a solution comprising excipients suitable for aerosolized intrapulmonary delivery. The solution can comprise one or more pharmaceutically acceptable carriers and/or excipients. Pharmaceutically acceptable refers to approved or approvable by a regulatory agency of the Federal or a state government or listed in the U.S. Pharmacopoeia or other generally recognized pharmacopoeia for use in animals, and more particularly in humans. Preferably, the solution is buffered such that the solution is in a relatively neutral pH range, for example, a pH in the range of about 4 to 8, for example, a pH in the range of about 5-7. In some embodiments, the steroids or neurosteroids (e.g., allopregnanolone) is formulated in a buffered solution, for example, phosphate-buffered saline.
[0062] In various embodiments, the steroids or neurosteroids (e.g., allopregnanolone) is prepared as a concentrated aqueous solution. Ordinary metered dose liquid inhalers have poor efficiency for the delivery to the deep lung because the particle size is not sufficiently small (Kim et al., 1985 Am Rev Resp Dis 132:137-142; and Fan et al., 1995 Thorax 50:639-644). These systems are therefore used mostly for local delivery of drugs to the pulmonary airways. In addition, metered doses inhalers may not be able to deliver sufficient volumes of even a concentrated steroids or neurosteroids (e.g., allopregnanolone) solution to produce the desired rapid antiseizure effect. Accordingly, in various embodiments, a metered doses inhaler is not used for delivery of the steroids or neurosteroids (e.g., allopregnanolone). In one embodiment a nebulization system with the capability of delivering <5 μm particles (e.g., the PARI LC Star, which has a high efficiency, 78% respirable fraction 0.1-5 μm. see, e.g., pari.com) is used for intrapulmonary administration. Electronic nebulizers which employ a vibrating mesh or aperture plate to generate an aerosol with the required particle size can deliver sufficient quantities rapidly and find use (See, e.g., Knoch and Keller, 2005 Expert Opin Drug Deliv 2: 377-390). Also, custom-designed hand-held, electronic nebulizers can be made and find use.
[0063] Aerosolized delivery of steroids or neurosteroids (e.g., allopregnanolone) allows for reduced dosing to achieve desired efficacy, e.g., in comparison to intravenous or intranasal delivery. Appropriate dosing will depend on the size and health of the patient and can be readily determined by a trained clinician. Initial doses are low and then can be incrementally increased until the desired therapeutic effect is achieved with little or no adverse side effects. In various embodiments, the steroids or neurosteroids (e.g., allopregnanolone) are administered via the intrapulmonary route at a dose that is about 10%, 15%, 25%, 50% or 75% of established doses for their administration via other routes (e.g., via oral, intravenous or intranasal administration). In some embodiments, the steroids or neurosteroids (e.g., allopregnanolone) are administered via the intrapulmonary route at a dose in the range of about 0.05 mg/kg to about 1.0 mg/kg, for example, about 0.2 mg/kg to about 0.8 mg/kg, for example, about 0.05 mg/kg, 0.08 mg/kg, 0.1 mg/kg, 0.2 mg/kg, 0.3 mg/kg, 0.4 mg/kg, 0.5 mg/kg, 0.6 mg/kg, 0.7 mg/kg, 0.8 mg/kg, 0.9 mg/kg, or 1.0 mg/kg. In some embodiments, the steroids or neurosteroids (e.g., allopregnanolone) are administered via the intrapulmonary route at a dose in the range of about 10 μg/kg to about 80 μg/kg, for example, about 20 μg/kg to about 60 μg/kg, for example, about 25 μg/kg to about 50 μg/kg, for example, about 10 μg/kg, 15 μg/kg, 20 μg/kg, 25 μg/kg, 30 μg/kg, 35 μg/kg, 40 μg/kg, 45 μg/kg, 50 μg/kg, 60 μg/kg, 70 μg/kg, or 80 μg/kg. In some embodiments, the steroids or neurosteroids (e.g., allopregnanolone) are administered via the intrapulmonary route at a dose in the range of about 0.3 μg/kg to about 3.0 μg/kg.
[0064] To prepare compositions, the steroid or neurosteroid (e.g., allopregnanolone) is mixed with a suitable pharmaceutically acceptable carrier. Upon mixing or addition of the compound(s), the resulting mixture may be a solution, suspension, emulsion, or the like. Liposomal suspensions may also be suitable as pharmaceutically acceptable carriers. These may be prepared according to methods known to those skilled in the art. The form of the resulting mixture depends upon a number of factors, including the intended mode of administration and the solubility of the steroid or neurosteroid (e.g., allopregnanolone) in the selected carrier or vehicle. The effective concentration is sufficient for lessening or ameliorating at least one symptom of the disease, disorder, or condition treated and may be empirically determined.
[0065] Pharmaceutical carriers or vehicles suitable for administration of the steroids or neurosteroids (e.g., allopregnanolone) provided herein include any such carriers known to those skilled in the art to be suitable for the particular mode of administration (e.g., cyclodextrins). In addition, the active materials can also be mixed with other active materials that do not impair the desired action, or with materials that supplement the desired action, or have another action. The steroids or neurosteroids (e.g., allopregnanolone) may be formulated as the sole pharmaceutically active ingredient in the composition or may be combined with other active ingredients.
[0066] Where the steroids or neurosteroids (e.g., allopregnanolone) exhibit insufficient solubility, methods for solubilizing may be used. Such methods are known and include, but are not limited to, using cosolvents such as dimethylsulfoxide (DMSO), using surfactants such as Tween™, and dissolution in aqueous sodium bicarbonate. Derivatives of the steroids or neurosteroids (e.g., allopregnanolone), such as salts or prodrugs may also be used in formulating effective pharmaceutical compositions.
[0067] The concentration of the steroid or neurosteroid (e.g., allopregnanolone) is effective for delivery of an amount upon administration that lessens or ameliorates at least one symptom of the disorder for which the compound is administered and/or that is effective in a prophylactic context. Typically, the compositions are formulated for single dosage (e.g., daily) administration.
[0068] The steroids or neurosteroids (e.g., allopregnanolone) may be prepared with carriers that protect them against rapid elimination from the body, such as time-release formulations or coatings. Such carriers include controlled release formulations, such as, but not limited to, microencapsulated delivery systems. The active steroid or neurosteroid (e.g., allopregnanolone) is included in the pharmaceutically acceptable carrier in an amount sufficient to exert a therapeutically useful effect in the absence of undesirable side effects on the patient treated. The therapeutically effective concentration may be determined empirically by testing the steroids or neurosteroids (e.g., allopregnanolone) in known in vitro and in vivo model systems for the treated disorder. A therapeutically or prophylactically effective dose can be determined by first administering a low dose, and then incrementally increasing until a dose is reached that achieves the desired effect with minimal or no undesired side effects.
[0069] In various embodiments, the steroids or neurosteroids (e.g., allopregnanolone) and/or analogs thereof can be enclosed in multiple or single dose containers. The enclosed compounds and compositions can be provided in kits, for example, including component parts that can be assembled for use. For example, a compound inhibitor in lyophilized form and a suitable diluent may be provided as separated components for combination prior to use. A kit may include a compound inhibitor and a second therapeutic agent for co-administration. The inhibitor and second therapeutic agent may be provided as separate component parts. A kit may include a plurality of containers, each container holding one or more unit dose of the compounds. The containers are preferably adapted for the desired mode of administration, including, but not limited to depot products, pre-filled syringes, ampules, vials, and the like for parenteral administration
[0070] The concentration and/or amount of steroid or neurosteroid (e.g., allopregnanolone) in the drug composition will depend on absorption, inactivation, and excretion rates of the steroid or neurosteroid (e.g., allopregnanolone), the dosage schedule, and amount administered as well as other factors known to those of skill in the art.
[0071] The active ingredient may be administered at once, or may be divided into a number of smaller doses to be administered at intervals of time. It is understood that the precise dosage and duration of treatment is a function of the disease being treated and may be determined empirically using known testing protocols or by extrapolation from in vivo or in vitro test data. It is to be noted that concentrations and dosage values may also vary with the severity of the condition to be alleviated. It is to be further understood that for any particular subject, specific dosage regimens should be adjusted over time according to the individual need and the professional judgment of the person administering or supervising the administration of the compositions, and that the concentration ranges set forth herein are exemplary only and are not intended to limit the scope or practice of the claimed compositions.
[0072] 5. Monitoring Efficacy
[0073] In various embodiments, administration of a steroid or neurosteroid (e.g., allopregnanolone) to a subject results in the prevention or mitigation of one or more symptoms of the disease condition being treated (e.g., traumatic brain injury, Alzheimer's disease, epilepsy, anxiety, fragile X syndrome, post-traumatic stress disorder, lysosomal storage disorders (Niemann-Pick type C disease), depression (including post-partum depression), premenstrual dysphoric disorder, alcohol craving, and smoking cessation). Symptoms of disease can be compared before and after administration of a steroid or neurosteroid (e.g., allopregnanolone) to the subject. Administration of the steroid or neurosteroid (e.g., allopregnanolone) to the subject is considered to be effective if the symptoms no longer occur after administration (e.g., seizures), or if the symptoms are reduced, alleviated and/or mitigated after administration.
[0074] In various embodiments, administration of a steroid or neurosteroid (e.g., allopregnanolone) to a subject results in the prevention of the occurrence of an impending seizure and/or the termination or abortion of a seizure in progress.
[0075] In various embodiments, efficacy can be monitored by the subject. For example, in a subject experiencing aura or receiving a warning from a seizure prediction device, the subject can self-administer a dose of the steroid or neurosteroid (e.g., allopregnanolone). If the steroid or neurosteroid (e.g., allopregnanolone) is administered in an efficacious amount, the sensation of aura should subside and/or the seizure prediction device should no longer predict the imminent occurrence of an impending seizure. If the sensation of aura does not subside and/or the seizure prediction device continues to predict an impending seizure, a second dose of steroid or neurosteroid (e.g., allopregnanolone) can be administered.
[0076] In other embodiments, the efficacy is monitored by a caregiver. For example, in a subject experiencing the onset of a seizure or in situations where a seizure has commenced, the subject may require administration of the steroid or neurosteroid (e.g., allopregnanolone) by a caregiver. If the steroid or neurosteroid (e.g., allopregnanolone) is administered in an efficacious amount, the seizure, along with the subject's symptoms of the seizure, should terminate or abort. If the seizure does not terminate, a second dose of the steroid or neurosteroid (e.g., allopregnanolone) can be administered.
EXAMPLES
[0077] The following examples are offered to illustrate, but not to limit the claimed invention.
Example 1
Anticonvulsant Activity of Intravenous and Intramuscular Allopregnanolone
Rationale:
[0078] Treatment of status epilepicus requires rapid administration of antiseizure agents, which are typically delivered either by the intravenous (i.v.) or intramuscular (i.m.) routes. Allopregnanolone (3α-hydroxy-5α-pregnan-20-one; 5α,3α-P), an endogenous progesterone-derived steroid that is a positive allosteric modulator of GABA A receptors, is a powerful antiseizure agent with potential in the treatment of status epilepticus. The objective of this study was to determine the dosing of allopregnanolone to protect against seizures when delivered i.v. and i.m.
Methods:
[0079] The mouse 6 Hz and pentylenetetrazol seizure models were used. Solutions of 5α,3α-P were made in 6% (0.5 and 1.5 mg/ml) sulfobutylether-β-cyclodextrin sodium salt (Captisol®) in 0.9% saline. The solutions were injected i.v. or i.m. (1, 2 and 30 min or 2 and 30 min, respectively) prior to administration of the 6 Hz electrical stimulus or PTZ (80 mg/kg, i.p.). In case of the PTZ model, animals were observed for 30 min and times to myoclonic jerks and clonic and tonic seizures were recorded. Anticonvulsant activity was assessed by the delay in onset of seizure signs. Allopregnanolone plasma levels in rats were determined by LC-MS.
Results:
[0080] 5α,3α-P exhibited protective activity in the 6 Hz test 1-15 min after i.v. infusion (1.5 mg/kg) but was inactive at 30 min. In contrast, with i.m. administration (3 mg/kg) the onset of protective activity was slower (within 2 min) and lasted <2 h. At a dose of 0.1 mg/kg i.v. 5α,3α-P failed to significantly delay seizure onset in the PTZ model at all pretreatment times (1, 2 and 30 min) whereas a dose of 0.5 mg/kg administered 1 min before PTZ caused a marked delay for myoclonic jerks and clonic seizures and in 62.5% of animals prevented tonic seizures and mortality that invariably accompanies tonic seizures. When injected 2 min before PTZ 5α,3α-P (0.5 mg/kg) caused a similar increase in time to onset of seizures signs and prevented tonic seizures in 25% of animals.
[0081] 5α,3α-P at a dose of 1.5 mg/kg completely prevented tonic seizures and mortality when injected i.v. 1 and 2 min before PTZ. When injected i.m. 2 min before PTZ, 0.25, 0.5 and 1.5 mg/kg 5α,3α-P protected 0%, 50% and 100%, respectively, of animals from tonic seizures. 5α,3α-P at the dose of 1.5 mg/kg i.m. provided significant protection against tonic seizures when injected 30 min before PTZ; the same dose injected i.v. 30 min before PTZ was inactive. In rats, an i.v. bolus dose of 0.5 and 1.0 mg/kg 5α,3α-P caused mean peak plasma levels (2 min) of 337 and 746 ng/ml, respectively; for both doses, the pooled mean two component halftimes were 2 and 22 min.
Conclusions:
[0082] Our results demonstrate that i.v. 5α,3α-P provides very rapid but transitory anticonvulsant activity. When injected i.m., 5α,3α-P acts comparably quickly and has a longer duration of action. Parenteral 5α,3α-P may be useful for the acute treatment of seizures.
Detailed Methods
[0083] Animals.
[0084] Male NIH Swiss mice (22-30 g) served as subjects, and all procedures used in these studies were conducted in accordance with the University of California, Davis, Institutional Animal Care and Use Committee the Animal Care and Use policies in strict compliance with the Guide for the Care and Use of Laboratory Animals of the National Research Council (National Academy Press, Washington, D.C.; on the internet at nap.edu/readingroom/books/labrats/).
[0085] Test Substances and Drug Administration.
[0086] Allopregnanolone (3α-hydroxy-5α-pregnan-20-one; 5α,3α-P) was synthesized by a SAFC Pharma Inc, Madison, Wis., USA and Captisol (sulfobutylether-beta-cyclodextrin sodium salt) was provided by Ligand Pharmaceuticals, Inc. La Jolla, Calif., USA. Solutions of 5α,3α-P were made in 6% (0.5 and 1.5 mg/ml) or 24% (6 mg/kg) sulfobutylether-β-cyclodextrin sodium salt (Captisol®) in 0.9% saline. The volumes used for all injections were 10-20 ml/kg of body weight. In order to establish time courses for protection by 5α,3α-P in the 6-Hz electrical-stimulation (32 mA, 3 s) model, 5α,3α-P (0.5-6 mg/kg) was administered intravenously (i.v.), intramuscularly (i.m.), subcutaneously (s.c.) or orally (p.o.) before electrical stimulation. In the PTZ seizure test, 5α,3α-P or vehicle were administered i.v. or i.m. 1, 2 or 30 min before PTZ.
Seizures Models
[0087] 6-Hz Seizure Test
[0088] (Kaminski, et al., Epilepsia (2004) 45:1-4): 3-s corneal stimulation (200-μs duration, 32-mA monopolar rectangular pulses at 6 Hz) was delivered by a constant-current device (ECT Unit 5780; Ugo Basile, Comerio, Italy). After the stimulation, the animals exhibited a “stunned” posture associated with rearing and automatic movements that lasted from 60 to 120 s in untreated animals. The experimental end point was protection against the seizure: an animal was considered to be protected if it resumed its normal exploratory behavior within 10 s of stimulation.
[0089] Pentylenetetrazol Seizure Test
[0090] (Kokate, et al., J Pharmacol Exp Ther (1994) 270:1223-9): mice were injected intraperitoneally with PTZ (80 mg/kg) and were observed for a 30-min period. The time of onset of myoclonic jerks, clonus and tonic extension was recorded.
[0091] Surgery and Blood Collection.
[0092] Male rats were implanted with indwelling jugular catheters as described (Baumann, et al., J Neurosci . (1998) 18: 9069-77). Animals were allowed to recover for at least one week. Experiments were carried out while the animal resided in its home cage. Rats received i.v. injection of vehicle or 5α,3α-P and serial blood samples were withdrawn into chilled tubes at 1, 2, 10, 15, 30, 60 and 120 min after i.v. injection. 5α,3α-P and D4-5α,3α-P (internal standard) were extracted with SPE method from rat's plasma. The extracted 5α,3α-P and D4-5α,3α-P were quantified with ultra-performance liquid chromatography (UPLC)/Atmospheric-pressure chemical ionization (APCI)/tandem mass spectrometry (MS/MS).
[0093] Data Analysis.
[0094] Results are expressed as mean±S.E.M.; the significance of the difference in the responses of treatment groups with respect to control is based on one-way analysis of variance (ANOVA) followed by specific post hoc comparisons using Dunnett's test. Differences were considered statistically significant when the probability of error was less than 0.05 (p<0.05).
[0095] Results are shown in FIGS. 1-10 . Our results demonstrate that i.v. 5α,3α-P provides very rapid but transitory anticonvulsant activity. When injected i.m., 5α,3α-P acts comparably quickly and has a longer duration of action. Low bioavailability of 5α,3α-P after oral administration prolongs the time of the peak effect and duration of action. Parenteral 5α,3α-P is useful for the acute treatment of seizures.
[0096] It is understood that the examples and embodiments described herein are for illustrative purposes only and that various modifications or changes in light thereof will be suggested to persons skilled in the art and are to be included within the spirit and purview of this application and scope of the appended claims. All publications, patents, and patent applications cited herein are hereby incorporated by reference in their entirety for all purposes. | The present invention relates to methods of preventing, inhibiting, delaying, and/or mitigating seizures by administration of a steroid, e.g., a neurosteroid, e.g., allopregnanolone. | 0 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a divisional of U.S. Ser. No. 14/300,640, filed Jun. 10, 2017.
FIELD OF THE INVENTION
[0002] The invention relates generally to row-crop planters or seeders and, in particular, to seed meters of planters for planting multiple varieties of seed.
BACKGROUND OF THE INVENTION
[0003] Modern farming practices strive to increase yields of agricultural fields. Technological advances of planters allow for better agronomic characteristics at the time of planting, such as providing more accurate seed depth, improved uniformity of seed depth across the planter, and improved accuracy of in-row seed spacing. However, a single field can have performance inconsistencies between different areas. That is because a field can have a wide variety of soil types and management zones such as irrigated and non-irrigated zones in different areas. Seed companies are developing multiple varieties of each of their seed product types, with the different varieties offering improved performance characteristics for different types of soil and management practices. Efforts have been made to plant multiple varieties of a particular seed product type in different areas of fields with different soil types or management zones. These efforts include planters that have different bulk fill hoppers and require the reservoir for each seed meter to be completely cleaned out or planted out before a different seed variety can be delivered to the seed meters. Some planters allow for planting two varieties and include two separate and distinct seed meters at every row unit.
SUMMARY OF THE INVENTION
[0004] The present invention is directed to a seed meter that allows for absolute and instantaneous switching seed types being planted during a single planting pass, without requiring multiple seed meters at every row unit or emptying out or planting out a first seed type before switching to a different seed type. The seed meter has more than one seed disk in its housing for selectively planting one of multiple seed types. The seed meter is configured to activate a single seed disk and deactivate the others so that only seeds conveyed by the activated seed disk are delivered out of the seed meter for planting at a given time. By on-the-move synchronizing of activating and deactivating of the different seed disks within the seed meter, an absolute and instantaneous switching of the seed type being planted within a single row is achieved.
[0005] According to one aspect of the invention, a seed meter is provided for planting multiple types of seed in a single planting pass during row-crop planting of an agricultural field. The seed meter has a housing supported relative to a row unit of a planter. A first seed disk is rotatable within the housing for conveying seeds of a first type through the housing and out of the seed meter. A second seed disk is rotatable within the housing for conveying seeds of a second type through the housing and out of the seed meter. The first and second seed disks may be parallel to or angled with respect to each other. A seed disk drive system activates and deactivates the first and second seed disks for selectively delivering a corresponding one of the first and second seed types out of the housing for planting of an agricultural field. This allows a producer to plant multiple varieties of seed within the same field in a single planting session and even during a single planting pass without having to add additional row units or seed meters.
[0006] According to another aspect of the invention, the seed meter has a seed meter reservoir with a first seed chamber storing seeds of the first type within the housing for receipt by the first seed disk when the first seed disk is activated. A second seed chamber stores seeds of the second type within the housing for receipt by the second seed disk when the second seed disk is activated. A separator wall within the seed meter reservoir may separate the first and second seed chambers from each other. The separator wall may be arranged transversely between the first and second seed disks with the first seed chamber between the separator wall and the first seed disk and the second seed chamber between the separator wall and the second seed disk. Separate primary seed conduits may direct separately stored seed types from bulk storage into the seed chambers of the seed meter, which may include delivery of the seed from bulk storage into compartments of an on-row storage system which may be defined by a vented mini-hopper(s) that feeds the seed chambers of the seed meter. In another embodiment, a seed gate system(s) is arranged to selectively direct seeds of different types through a single primary seed conduit into different seed chambers of the seed meter, for example, by way of the compartments of the mini-hopper(s). In yet another embodiment, the on-row compartments provide the bulk storage of the different types of seed which are gravity-fed into the seed chambers of the seed meter.
[0007] According to another aspect of the invention, the first and second seed disks are arranged generally parallel to each other. A single seed tube may receive seeds released from both the first and second seed disks for delivery onto the agricultural field. This provides a single unitary seed meter of relatively simple construction that can offer on-the-move absolute and instantaneous switching of the seed type being planted during a single planting pass.
[0008] According to another aspect of the invention, the first and second seed disks are arranged at an angle with respect to each other. This provides a seed meter housing that encloses multiple seed disks that each releases seed at substantially the same seed release location within the seed meter housing for delivery out of a seed tube, which reduces seed bounce within the seed tube.
[0009] According to another aspect of the invention, the housing of the seed meter has a first side portion and a second side portion. A first seed disk assembly is arranged within the first side portion of the housing for rotatably conveying individual seeds of a first type through the housing and out of the seed meter for individually planting the seeds of the first variety during row-crop planting of an agricultural field. A second seed disk assembly is arranged within the second side portion of the housing for rotatably conveying individual seeds of a second type through the housing and out of the seed meter for individually planting the seeds of the second variety during row-crop planting of the agricultural field. This allows for planting multiple varieties of seed within the same field without having to add additional row units or seed meters.
[0010] According to another aspect of the invention, each of the first and second seed disk assemblies includes a seed disk rotatable within a cavity defined by the respective one of the first and second side portions of the housing. A seed disk drive system may selectively rotate the seed disks of the first and second seed disk assemblies independently with respect to each other. This allows for quick switching or changeovers from planting seeds of a first seed type to planting seeds of a second seed type.
[0011] According to another aspect of the invention, the seed disk drive system includes a clutch arranged with respect to each of the first and second seed disk assemblies. Each clutch selectively engages/disengages transmission of a rotation driving power to the respective seed disk for permitting/preventing rotation of the corresponding seed disk of the first and second seed disk assemblies. The clutch may be an air clutch or an electromechanical clutch. This allows for a seed meter capable of delivering multiple types of seed by activating and/or deactivating multiple seed disks within the seed meter.
[0012] According to another aspect of the invention, the seed disk drive system includes a motor drive at each of the first and second seed disk assemblies. A controller controls the motor drive(s) to permit/prevent transmission of a rotation driving power to the seed disks. In this way, rotation of one of the seed disks, a deactivated seed disk, can be stopped while the other seed disk, an activated seed disk, is rotated. The motor drive may be a pneumatic motor or an electric motor. This allows for a seed meter capable of delivering multiple types of seed by activating and/or deactivating multiple seed disks within the seed meter.
[0013] According to another aspect of the invention, the seed meter has a seed tube that receives seeds released from both the first and second seed disk assemblies for delivery onto the agricultural field. This allows for sequentially delivering different types of seed from a single seed meter into a single seed bed.
[0014] According to another aspect of the invention, a method of planting multiple types of seed in a single planting pass during planting of an agricultural field is provided. The method includes rotating a first seed disk in a seed meter to convey seeds of a first type through the seed meter and deliver the seeds of the first type onto a first location of an agricultural field. A second seed disk is rotated in the seed meter to convey seeds of a second type through the seed meter and deliver the seeds of the second type onto a second location of the agricultural field. The first seed disk may be arranged within a housing of the seed meter to rotate past a first seed chamber storing seeds of the first type within the housing of the seed meter. The second seed disk may be arranged within the housing to rotate past a second seed chamber storing seeds of the second type within the housing of the seed meter. An instantaneous switchover can be made from planting seeds of the first type to planting seeds of the second type. This can be done by deactivating the first seed disk and activating the second seed disk seed-type switching event. During the seed-type switching event, release of a final seed of the first seed type is sequentially followed by an initial seed of the second seed type. This can be done within a single row without creating a skip event. This provides maintaining a constant in-row seed spacing through the seed-type switching event, whereby an in-row seed spacing at a transition between the first and second seed types is the same as the in-row seed spacing within each of the first and second seed types.
[0015] According to another aspect of the invention, each seed meter of a planter may be individually controlled to control switching from delivering seeds of the first seed type to delivering seeds of the second seed type on a per-row basis. Different groups of seed meters corresponding to different sections of a planter may be separately controlled to control switching from delivering seeds of the first type to delivering seeds of the second seed type from the planter on a per-section basis. All seed meters of the planter may be simultaneously controlled to control switching from delivering seeds of the first seed type to delivering seeds of the second seed type on a whole-planter basis. This allows for different versions of seed variety switchover control based on the amount of precision or pinpoint control needed for different seed variety placements within different fields or based on producer/operator preference.
[0016] Other aspects, objects, features, and advantages of the invention will become apparent to those skilled in the art from the following detailed description and accompanying drawings. It should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the present invention, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the present invention without departing from the spirit thereof, and the invention includes all such modifications.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Preferred exemplary embodiments of the invention are illustrated in the accompanying drawings in which like reference numerals represent like parts throughout.
[0018] FIG. 1 illustrates a pictorial view of a planter incorporating a seed meter in accordance with the present invention;
[0019] FIG. 2A illustrates a simplified schematic view of the planter of FIG. 1 and cross-sectional representation of a seed meter in accordance with the present invention;
[0020] FIG. 2B illustrates a variant of the seed meter of FIG. 2A ;
[0021] FIG. 2C illustrates another variant of the seed meter of FIG. 2A ;
[0022] FIG. 3 illustrates an exploded pictorial view of a variant of the seed meter of FIG. 2A ;
[0023] FIG. 4 illustrates a simplified schematic view of a variant of the seed meter shown in FIG. 2A ;
[0024] FIG. 5 illustrates a simplified side elevation view of a variant of the seed meter shown in FIG. 2A ; and
[0025] FIG. 6 illustrates a screen shot showing a seed-type prescription map for use with the planter incorporating the seed meter(s) in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] Referring now to the drawings and specifically to FIG. 1 and the simplified schematic representations of FIGS. 2A-2C , seed meters 5 of row units 7 of a planter 9 are configured for planting multiple types or varieties of seed. As explained in greater detail elsewhere herein, each seed meter 5 can switch, for example, absolutely, instantaneously, and automatically, between planting of different types or varieties of seed during a single planting pass of row-crop planting of an agricultural field with the planter 9 . Planter 9 may be one of the EARLY RISER® series planters available from Case IH and is typically pulled by a traction device such as a tractor 11 . The planter 9 has a frame 13 that supports the multiple row units 7 that are substantially identical. Each row unit 7 includes a respective seed meter 5 and various support components for supporting the seed meter 5 and corresponding ground-engaging components.
[0027] Referring now to FIG. 1 , such support components include a sub-frame 15 that is connected to the frame 13 of the planter 9 by way of a parallel linkage system 16 ( FIG. 5 ) and supports the seed meter 5 and furrow opening 17 and closing mechanisms 19 toward front and back ends of the row unit 7 . The opening and closing mechanisms 17 , 19 may include opener disks and closing disks, respectively, or other ground-engaging tools for opening and closing a furrow. Each row unit 7 may include a gauge wheel 21 configured for adjusting furrow depth by limiting soil penetration of the furrow-opening mechanism 17 while creating a furrow, and a press wheel 23 may be arranged to roll over the closed furrow to firm the soil over the seed to further close the furrow and promote favorable seed-to-soil contact.
[0028] Referring now to FIGS. 2A-2C , in these embodiments, seeds 25 are held in bulk storage in a bulk storage system 27 with at least one bulk fill hopper 29 , shown here in each of FIGS. 2A-2C as having two central bulk fill hoppers 29 supported by the frame 13 of the planter 9 . The bulk storage system 27 has multiple compartments 31 , shown here as spaces within each of the bulk-fill hoppers 29 that are separated by divider walls or partitions 33 . In another embodiment, the compartments 31 are defined by separate and discrete containers themselves, such as the bulk fill hoppers 29 . In another embodiment, such as that shown in FIG. 5 , at least some of the bulk fill hoppers 29 are not centrally located with respect to the planter 9 and remote from the row units 7 , but are mounted on the row units 7 themselves in a gravity-feed relationship with the respective seed meters explained in greater detail elsewhere herein. Regardless of where the hoppers 29 are located, the different compartments 31 of the hoppers 29 may hold seeds 25 of a common plant type but different varieties or types 25 a , 25 b for planting in different type or variety zones of an agricultural field defined at least in part by characteristics relating to at least one of soil type and management type. Although the seed 25 may be described elsewhere herein as different types 25 a , 25 b , it is understood that the description of the different types includes different varieties. In other words, the different types 25 a , 25 b of seed 25 include not only different varieties of the same plant species, but also different seed products. Different seed products can include seeds of different species, coated and uncoated seeds, such as insecticide coated and non-insecticide coated seeds. The different seed products can also include refuge in a bag seed and non-refuge in a bag seed, plant-parasite resistant seed and non-plant-parasite resistant seed such as cyst nematodes resistant seeds and non-cyst nematodes resistant seeds, herbicide-tolerant seed and non-herbicide tolerant seed, or other different products.
[0029] Still referring to FIGS. 2A-2C , three exemplary arrangements of seed meters 5 are shown in the three row units 7 as seed meters 5 a , 5 b , and 5 c , in FIGS. 2A, 2B, and 2C , respectively, each of which can plant multiple types or varieties of seed. Each seed meter 5 has a pair of metering assemblies 26 for singulating and selectively delivering different types 25 a , 25 b of seed 25 from the seed meter 5 . The seed meter 5 a of FIG. 5A and the seed meter 5 b in FIG. 2B have transversely arranged metering assemblies 26 . The seed meter of FIG. 2C has longitudinally arranged metering assemblies 26 . Regardless of whether the metering assemblies 26 are arranged transversely or longitudinally and referring again to FIGS. 2A-2C , each seed meter 5 is operably connected to an airflow system 34 ( FIG. 4 ) that includes a positive air pressure source and a vacuum source for establishing positive and vacuum pressures and corresponding air flows for delivery seed 25 to the seed meters 5 and for moving the seeds 25 through the seed meter 5 . The positive air pressure source and vacuum sources can be known pumps, fans, blowers, and/or other known airflow system components. Each seed meter 5 has a housing 35 defining the first and second side portions 37 , 39 shown as including a left-hand cover (LH) and a right-hand cover (RH). In the seed meters 5 a , 5 b of FIGS. 2A-2B with the transversely arranged metering assemblies 26 , each of the left-hand and right-hand covers LH, RH has a vacuum inlet (VI) for connecting the first and second side portions 37 , 39 to the vacuum source. In the seed meter 5 c of FIG. 2C with the longitudinally arranged metering assemblies 26 , the left-hand cover LH is shown with two vacuum inlets (VI) for connecting the first side portion 37 to the vacuum source at two locations. An intermediate portion 41 of the housing 35 is arranged between the first and second side portions 37 , 39 . A seed meter reservoir 43 defining a multiple chamber or split reservoir is arranged within the intermediate portion 41 of the housing 35 . In the seed meter 5 c of FIG. 2C with the longitudinally arranged metering assemblies 26 , the reservoir 43 extends from the intermediate portion 41 into the second side portions 39 of the housing 35 . In the seed meters 5 a , 5 b of FIGS. 2A-2B with the transversely arranged metering assemblies 26 , a separator wall 45 within the seed meter reservoir 43 separates the seed meter reservoir into a first seed chamber 47 storing seeds of the first type 25 a and a second seed chamber 49 storing seeds of the second type 25 b within seed meter housing 35 .
[0030] Referring now to FIGS. 2A, 2B, and 3 , in the seed meters 5 a , 5 b with the transversely arranged metering assemblies 26 , one of the metering assemblies 26 includes a first seed disk assembly 51 having a first seed disk 53 arranged within the first side portion 37 of the seed meter housing 35 . The other metering assembly 26 includes a second seed disk assembly 55 having a second seed disk 57 arranged within the second side portion 39 of the seed meter housing 35 . Inwardly facing surfaces 59 , 61 of the first and second seed disks 53 , 57 face toward and define transverse outer peripheries of the first and second seed chambers 47 , 49 . Outwardly facing surfaces 63 , 65 of the first and second seed disks 53 , 57 face toward and are spaced from the left-hand and right-hand covers LH, RH of the first and second side portions 37 , 39 . This provides vacuum pressure chambers 67 between the outwardly facing surface 63 and the left-hand cover LH in between the outwardly facing surface 65 and right-hand cover RH as imparted by the negative pressure airflow through vacuum inlets VI of the left-hand and right-hand covers LH, RH of the seed meter housing first and second side portions 37 , 39 . The vacuum pressure in the vacuum pressure chamber 67 allows seeds 25 to be drawn and held against the seed pockets and/or holes 69 ( FIG. 3 ) of the seed disks 53 , 57 to rotatably convey the seeds 25 through the seed meter housing 35 to be released from the seed disk(s) 53 , 57 within a discharge segment 71 ( FIG. 2A-2B ) at release locations 73 in the seed meter housing 35 . The discharge segment 71 is defined between a forward facing wall 75 of the seed meter housing 35 , the inwardly facing surfaces 59 , 61 of the seed disks 53 , 57 , and a divider wall 77 . The divider wall 77 extends in a transverse direction through the interior of the housing 35 , across a front of the seed meter reservoir 43 , and between the seed disks 53 , 57 .
[0031] Referring now to FIG. 2C , the above description of the seed meters 5 a , 5 b of FIGS. 2A-2B with the transversely arranged metering assemblies 26 applies to the seed meter 5 c of FIG. 2C with the longitudinally arranged metering assemblies 26 , while differing in the following ways. In the seed meter 5 c with the longitudinally arranged metering assemblies 26 , there is no separator wall 4 and the left-hand cover LH has two vacuum inlets VI aligned with the first and second seed disk assemblies 51 , 55 . The first and second seed chambers 47 , 49 are spaced from each other at front and back ends of the seed meter 5 c , respectively, with a pair of divider walls 77 and the discharge segment 71 , longitudinally separating the first and second seed chambers 47 , 49 .
[0032] Referring again to FIG. 2 , the seed meter 5 a has its seed disk assemblies 51 , 55 and seed disks 53 , 57 transversely aligned and arranged parallel to each other. As shown in FIG. 2B , the seed meter 5 b has its seed disk assemblies 51 , 55 and seed disks 53 , 57 transversely aligned and arranged at an angle with respect to each other, whereby axes of rotation of the seed disks 53 , 57 intersect to define an included angle of less than 180°. This embodiment shows the axis of rotation of the seed disks 53 , 57 of seed meter 5 b with an angle of about 30°, and the seed meter housing 35 defining a tapering width providing a generally V-shaped cross-sectional configuration. When comparing the two embodiments of the seed meters 5 a , 5 b of FIG. 2A-2B with the transversely arranged metering assemblies 26 , the V-shaped seed meter 5 b ( FIG. 2B ) with the angled seed disks 53 , 57 , has release locations 73 that are longitudinally aligned and transversely spaced and relatively closer to each other than the longitudinally aligned and transversely spaced release locations 73 of the seed meter 5 a ( FIG. 5A ) with the parallel seed disks 53 , 57 . The seed meter 5 c of FIG. 2C with the longitudinally arranged metering assemblies 26 has release locations 73 that are transversely aligned and longitudinally spaced with respect to each other. Regardless, and referring again to FIGS. 2A-2C , the release locations 73 are arranged to allow for dropping the seed 25 from the respective disk(s) 53 , 57 through an outlet 79 of the seed meter housing 35 of the seed meter 5 and into an inlet 81 of a common single seed tube 83 ( FIG. 3 ) that delivers the seed 25 onto the agricultural field, which allows for selective release of one of the seed types 25 a , 25 b at a given time and/or a given area of an agricultural field, as controlled by a control system 85 .
[0033] Referring now to FIGS. 2A-2C and 4 , the control system 85 controls selective delivery of the seed types 25 a , 25 b out of the seed meters 5 and initial delivery of the seed types 25 a , 25 b from the compartments 31 of the bulk fill hoppers 29 to the first and second seed chambers 47 , 49 of the seed meter reservoir 43 . Control system 85 includes a planter controller 87 and a tractor controller 89 that operably communicate with each other, for example, by way of an ISOBUS connection, for coordinating controls of planter 9 such as the seed meters 5 and tractor 11 ( FIG. 1 ) based on the type or variety zones VZ 1 , VZ 2 , VZ 3 of the agricultural field, which may correspond to a seed type or variety prescription map PM as shown in FIG. 6 .
[0034] Referring again to FIGS. 2A-2C , the planter controller 87 is shown including a controller 91 and a power supply 93 . The controller 91 of the planter controller 87 can include an industrial computer or, e.g., a programmable logic controller (PLC), along with corresponding software and suitable memory for storing such software and hardware including interconnecting conductors for power and signal transmission for controlling electronic, electro-mechanical, and hydraulic components of the seed meter 5 and other components of the planter 9 . The tractor controller 89 is configured for controlling operations of the tractor 11 such as controlling steering, speed, braking, shifting, and other operations of the tractor 11 . The tractor controller 89 is shown as including a controller 95 and power supply 97 . The tractor controller 89 is configured for controlling the functions of the tractor 11 by controlling the various GPS steering, transmission, engine, hydraulic, and/or other systems of the tractor 11 . Like the controller 91 of the planter controller 87 , the controller 95 of the tractor controller 89 can include an industrial computer or, e.g., a programmable logic controller, along with corresponding software and suitable memory for storing such software and hardware including interconnecting conductors for power and signal transmission for controlling electronic, electro-mechanical, and hydraulic components of the tractor 11 . A tractor interface system 99 is operably connected to the tractor controller 89 and includes a monitor and various input devices to allow an operator to see the statuses and control various operations of the tractor 11 from within the cab of the tractor 11 . The tractor interface system 99 may be a MultiControl Armrest™ console available for use with the Maxxum™ series tractors from Case IH.
[0035] Referring now to FIG. 4 , the control system 85 controls the loading of the seed types 25 a , 25 b and the first and second seed chambers 47 , 49 of the seed meter reservoir 43 by controlling a primary feed system 101 , which allows for use of a single primary seed conduit 103 to selectively direct the different seed types 25 a , 25 b into the different seed chambers 47 , 49 . Primary feed system 101 includes seed metering rollers 105 which may be calibrated fluted rollers arranged at outlets 107 of the bulk fill hoppers 29 , or the separate compartments 31 of a single bulk fill hopper 29 that holds both of the seed types 25 a , 25 b in its separate compartments 31 . The rollers 105 are driven to rotate by electric, pneumatic, or hydraulic motors (not shown) as controlled by the control system 85 to control release of the seed varieties 25 a , 25 b from the respective compartments 31 into a conduit segment 109 that connects to the primary seed conduit 103 . As shown in FIG. 4 , in this embodiment, the primary seed conduit 103 connects to an inlet 111 of an on-row storage system 113 that includes a vented mini-hopper 115 . The mini-hopper 115 has a separator wall 117 that divides its interior space to split compartments, shown as first and second mini-hopper chambers 119 , 121 which feed into and are connected with the first and second seed chambers 47 , 49 of the seed meter reservoir 43 . The control system 85 selectively fills and maintains seed pool level of the first and second mini-hopper chambers 119 , 121 by controlling a gate 123 of the primary feed system 101 arranged in the inlet 111 of the on-row storage system 113 . Gate 123 is shown as a pivoting blade that can be actuated by an actuator (not shown) controlled by the control system 85 to permit or prevent flow through the inlet 111 into the first and second mini-hopper chambers 119 , 121 by blocking or leaving uncovered corresponding openings 125 , 127 . Seed level sensors 129 are arranged in the first and second mini-hopper chambers 47 , 49 , 119 , 121 to provide signals allowing the control system 85 to evaluate how much seed 25 of the seed types 25 a , 25 b is in the first mini-hopper chamber 119 and second mini-hopper chamber 121 . In this way, the compartments 3 of the centrally located bulk fill hopper(s) 29 feed and maintain adequate fill level(s) of the seed varieties 225 a and 25 b in the first and second mini-hopper chambers 119 , 121 , as controlled by the control system 85 .
[0036] Referring now to FIG. 5 , this is a variation of the system described above with respect to FIG. 4 that includes both remote centrally located bulk storage and on-row bulk storage of seed 25 . Instead of storing all of the seed types 25 a , 25 b in centrally located bulk fill hoppers 29 , FIG. 5 shows a variation in which only a seed type with a greater required use-volume seed type(s), shown as seed type 25 a corresponding to a primary seed type, is stored in a compartment 31 of the centrally located bulk fill hopper(s) 29 represented as seed type 25 a stored in bulk fill hopper 29 a . A relatively lesser required use-volume seed type(s), shown as seed type 25 b as a secondary seed type, is stored in bulk on-row in the compartment 31 of the on-row bulk fill hopper 29 , represented as bulk fill hopper 29 b . In this embodiment, within each seed meter 5 , one of the seed disk assemblies 51 , 55 is fed the primary seed type 25 a from the mini-hopper 115 , which itself pneumatically receives the primary seed type 25 a from the remote and centrally located storage of the bulk fill hopper 29 a . The other one of the seed disk assemblies 51 , 55 is gravity-fed the secondary seed type 25 b from the on-row bulk fill hopper 29 b.
[0037] Referring again to FIGS. 2A-2C , regardless of the particular location(s) of bulk storage of the seed 25 , the control system 85 is configured to control each seed meter 5 to switch, for example, absolutely, instantaneously, and automatically, between planting of different types or varieties of seed during a single planting pass of row-crop planting of an agricultural field with the planter 9 . This may be done according to predetermined criteria, for example, based on the variety zones VZ 1 , VZ 2 , VZ 3 of the agricultural field provided by the seed type or variety prescription map PM ( FIG. 5 ), to accommodate selectively planting the seed types 25 a , 25 b based at least in part by characteristics relating to the soil type(s) and management type(s) of the variety zones VZ 1 , VZ 2 , VZ 3 . The control system 85 can absolutely and instantaneously switch which one of the seed types 25 a , 25 b is being planted by activating and/or deactivating the seed disk assemblies 51 , 55 to shut off half of the seed meter 5 and only deliver seed 25 from the half of the seed meter 5 that is not shut off, in a precisely synchronized manner.
[0038] Still referring to FIGS. 2A-2C , each seed meter 5 has a seed disk drive system 131 that is controlled by the control system 85 for selectively activating and/or deactivating the seed disk assemblies 51 , 55 . As shown in FIG. 2A , the seed meter 5 a with the parallel and transversely aligned seed disks 53 , 57 is shown with mechanical chain drives 133 that deliver rotating driving power from a rotating shaft 135 through clutches 137 and chains 139 , which rotate sprockets that are attached to spindles 141 that drive rotation of the seed disks 53 , 57 . Clutches 137 may be, for example, air clutches or electromechanical clutches, noting that the corresponding drives may include pneumatic motors or electric motors. Regardless, the control system 85 is operably connected to each of the clutches 137 to either disengage and prevent transmission of the rotation driving power from the shaft 135 or engage and permit transmission of the rotation driving power from the shaft 135 to each of the seed disks 53 , 57 . This selectively rotates the seed disks 53 , 57 in a direction toward the forward facing wall 75 to convey the seed 25 a , 25 b from the first and second seed chambers 47 , 49 for release into the seed tube 83 . As shown in FIG. 2B , in the seed meter 5 b with the transversely aligned and angled seed disks 53 , 57 , the seed disks 53 , 57 are also rotated in a direction toward the forward facing wall 75 to convey the seeds 25 a , 25 b from the first and second seed chambers 47 , 49 for release into the seed tube 83 . As shown in FIG. 2C , in the seed meter 5 c with the longitudinally aligned seed disks 53 , 57 , the seed disk 53 is rotated away from the forward facing wall 75 and the seed disk 57 is rotated toward the forward facing wall 75 to respectively convey seeds 25 a , 25 b from the first and second seed chambers 47 , 49 toward the seed tube 83 in a central portion of the seed meter 5 c . In FIGS. 2B-2C , each of the seed meters 5 b , 5 c is respectively shown with a direct drive-type seed disk drive system 131 having motor drives 143 . The motor drives 143 may include pneumatic motors or electric motors that rotate the spindles 141 , driving rotation of the seed disks 53 , 57 . It is understood that the motor drives 143 may instead rotate the seed disks 53 , 57 by rotating hubs, outer peripheries, or other portions of the seed disks 53 , 57 . Regardless, the control system 85 is operably connected to each of the motor drives 143 to either disengage and prevent transmission of the rotation driving power from the motor drives 143 or engage and permit transmission of the rotation driving power from the motor drives 143 to each of the seed disks 53 , 57 .
[0039] Referring now to FIGS. 2A-2C and 6 , during use, an operator first displays the seed type or variety prescription map PM ( FIG. 6 ) on the computer display or monitor of the tractor interface system 99 , which would typically be inside the tractor cab. The prescription map PM displays which type or variety zones VZ 1 , VZ 2 , VZ 3 are where in the agricultural field and which seed types 25 a , 25 b can be planted in the variety zones VZ 1 , VZ 2 , VZ 3 . As shown in FIG. 6 , in this embodiment, seed type 25 a is shown as acceptable for use in variety zones VZ 1 and VZ 3 , corresponding to recommended varieties A and C. Seed type 25 b is shown as acceptable for use in variety zone VZ 2 , corresponding to a recommended variety B. The operator inputs which seed type 25 a , 25 b is stored in compartments 31 of the bulk storage system 27 through the tractor interface system 99 . The prescription map PM may also contain the seed population that is to be planted for each type or variety 25 a , 25 b . The seed population could also be varied within the field based on soil type, organic matter, etc. The size of the seeds can also be input into the tractor interface system 99 . This information could also be made available in the database that is built from the desktop software when the prescription map PM was created.
[0040] Referring again to FIG. 4 , the control system 85 then determines seed level in each of the first and second mini-hopper chambers 119 , 121 based on a signal(s) from the corresponding seed level sensors 129 . If the seed level in the first and second mini-hopper chambers 119 , 121 is below a certain predetermined level corresponding to an amount needed for making at least one planting pass or starting planting, then the control system 85 sends a signal to rotate the metering roller(s) 105 of the compartment 31 holding the seed type 25 a , 25 b that was determined to be low. This releases the particular low seed type(s) 25 a , 25 b through the primary seed conduit 103 . The control system 85 also sends a signal to actuate the gate 123 at the inlet 111 of the on-row storage system 113 to ensure that the seed type 25 a , 25 b released from the bulk storage system 27 is directed to the correct one of the first and second mini-hopper chambers 119 , 121 of the mini-hopper 115 .
[0041] Referring again to FIGS. 2A-2C , by way of the GPS of the tractor controller 89 , the control system 85 is able to determine which seed type 25 a , 25 b is to be planted by each of the seed meters 5 based on the prescription map PM ( FIG. 6 ). For example, if seed type 25 a is to be planted from a particular row unit 7 of the planter 9 , the control system 85 activates the seed disk drive system 131 that activates the seed disk assembly 51 and rotates and delivers seed 25 of seed type 25 a from the seed disk 53 and deactivates the seed disk drive system 131 that deactivates the seed disk assembly 55 and prevents rotation of and delivery of seed 25 of seed type 25 b from the seed disk 57 at that particular row unit 7 . This synchronized activating and deactivating of the seed disk assemblies 51 , 55 provide a seed-type switching event. During the seed-type switching event, which may correspond to the planter 9 and/or tractor 11 crossing from one variety zone to another according the prescription map PM ( FIG. 5 ) and detected by the GPS of the tractor controller tractor controller 89 , release of a final seed 25 of the previously planted type is sequentially followed by an initial seed 25 of a subsequent or currently planted seed type. This can be done within a single row without creating a skip event, maintaining a constant in-row seed spacing through the seed-type switching event, whereby an in-row seed spacing at a transition between the first and second seed types is the same as the in-row seed spacing within each of the first and second seed types 25 a , 25 b.
[0042] Still referring to FIGS. 2A-2C , the control system 85 can be configured to individually control each of the seed meters 5 in this way to control switching from delivering seeds 25 of the first seed type 25 a to delivering seeds 25 of the second seed type 25 b on a per-row basis. In another embodiment, the control system 85 is configured to control groups of seed meters 5 in the same way within the same section of the planter 9 , for example, by giving common commands to all of the seed meters 5 within the same outer wing section(s) and/or inner or middle sections. This allows the control system 85 to control switching from delivering seeds 25 of the first type 25 a to delivering seeds 25 of the second seed type 25 b from the planter on a per-section basis. In yet another embodiment, the control system 85 is configured to control all of the seed meters 5 of the planter 9 in the same way. This allows for controlling switching from delivering seeds 25 of the first seed type 25 a to delivering seeds 25 of the second seed type 25 b on a whole-planter basis.
[0043] Many changes and modifications could be made to the invention without departing from the spirit thereof. The scope of these changes will become apparent from the appended claims. | A seed meter is provided for planting multiple types of seed and rapidly switching between the types being planted in a single planting pass of a planting session of row-crop planting. The seed meter has a split seed meter reservoir with a pair of seed meter chambers flanked by or next to a pair of seed disks. Activation and deactivation of the seed disks within the seed meter are synchronized to selectively deliver one type of seed from one of the seed meter chambers for delivery out of a single seed tube of the seed meter, which may provide absolute and instantaneous on-the-go seed switching within a single row from each seed meter. | 0 |
RELATED APPLICATIONS
[0001] None.
TECHNICAL FIELD
[0002] The present invention relates to implantable artificial joint assemblies and, more particularly, to a joint assembly that allows a predetermined amount of desired motion to a joint and that is particularly well suited for use in restructuring a spinal disc section of a spine including, but not limited to, the cervical region.
BACKGROUND OF THE INVENTION
[0003] In orthopedics it is known to use various types of reconstruction assemblies to repair bone joints that have become deteriorated, damaged or degenerative, such as due to trauma or disease. Some reconstructions involve the use of various components such as bone screws, plates, bone grafts, fusion implants and other components. Depending on the type and method of reconstruction selected, complete stabilization with no movement may be selected, or a predetermined amount of controlled movement may be selected. In one technique of spinal reconstruction, for example, fusion of adjacent vertebrae is achieved using one or more plates fastened to adjacent vertebral segments in order to join the vertebral segments in a predetermined relationship for stabilization, sometimes installing a fusion device such as an implant or bone graft.
[0004] While complete fusion and, thus, resultant loss of movement between adjacent vertebrae is sometimes prescribed, fusion does limit movement and in the long term may adversely affect the disc adjacent to the fused joint by imposing heightened stress and wear. An alternative to fusion using motion preservation devices restore significant motion and disc space height which minimizes stress concentrations and pain.
[0005] The various known systems for allowing controlled movement of joint reconstructions have shortcomings. Such shortcomings include lack of versatility so as to require multiple configurations and sizes of hardware on hand during surgery; prohibitively complex or expensive components; lack of anatomical correspondence with resultant poor fit; high stress concentrations and unnatural load forces on adjacent or fused bone segments; and other shortcomings. Known motion preservation devices are generally restricted to only very stable constructs and degenerative disc disease cases, which is only 5%-10% of all cases.
[0006] Known designs include an insert that is positioned between adjacent vertebrae and that contacts the vertebrae only on the end plates, where the load is transferred in an axial direction parallel to the axis of the vertebral column. Such designs do not provide adequate initial stability and thus are subject to, for example, lateral slide out of the insert. In some cases this problem could be addressed by implementing additional components such as plates or artificial ligaments, thereby increasing cost, complexity, surgery time, and invasiveness.
[0007] Other known designs include structures having sections that overlap end faces of adjacent vertebrae, but do not transfer axial load from the end faces. Instead, they have additional sections that are fastened to anterior or other portions of the vertebrae using bone screws or similar means, thereby supporting the load via the screws and the interior sections. This type of system not only causes high stress concentrations in and around the bone screws and their anchoring points in the vertebrae that are at risk for failure under load, but such a system prevents or shields axial load transfer through the end plates. By preventing load through the end plates, bone on-growth is significantly prevented.
[0008] Various known assemblies require a variety of sized sets to be on hand during surgery so that a surgeon can make a determination during the procedure as to which size will be best suited for a patient. This adds to the cost or reduces the versatility of the known assemblies.
[0009] Various known assemblies require a relatively large amount of surface area of a vertebra to the extend that constructing multiple, adjacent levels of reconstructed vertebrae (i.e., spanning two or more adjacent vertebral disc spaces) is prohibited simply because there is not enough space to install all of the components required. Other known designs include keel sections that are placed into channels cut into vertebral end faces. Such keel designs are subject to increased risk of cross-fracture of the vertebrae because they require channels to be cut which remove bone material crucial to structural integrity, and they often leave no room for additional implants such as on the opposite side of a vertebra.
OBJECTS OF THE INVENTION
[0010] It is an object of the present invention to provide a joint reconstruction system that overcomes the above-mentioned shortcomings and that achieves additional, inherent objectives apparent from the description set forth below.
[0011] It is a further object of the present invention to provide a joint reconstruction system particularly well suited, as described with respect to the preferred embodiments, for cervical spinal reconstruction where assemblies are constructed across more than one adjacent, or successive, vertebral spaces. These and other objects are described below or are inherent with respect to the present invention.
SUMMARY OF THE INVENTION
[0012] The present invention is described in the preferred embodiments as directed to a system of reconstruction for a spinal joint. It is understood, however, that the present invention is not limited to spinal reconstruction and, as understood by one skilled in the art,m may be adapted for application to other types of joints.
[0013] A preferred embodiment is directed to a three-piece, modular implant assembly that includes an upper part, a lower part, and a center core. The upper part and the lower part are identical in size and shape, though they could differ somewhat if desired or necessary. Each of the upper and the lower parts comprise a unitary body having an approximately ninety degree bend in it defining vertical and horizontal sections. The vertical section is preferably offset to one side of the vertical centerline (for reasons discussed below) and has at least one fastener hole to accommodate a fastener such as a bone screw. The hole may be slotted to allow predetermined sliding relative to a bone-screw and/or it may be shaped to allow pivoting relative to a bone-screw in instances where resultant freedom of movement of adjacent vertebrae is desired. This may be altered to a desired degree. The horizontal section has on its side facing toward the vertical section a vertebral end-face contacting surface that may be contoured and/or have projections to engage and hold securely to vertebral end faces, as well as to transfer axial load from the end faces. It may have a convex shape to it that fits and mates with the natural anatomy of the end faces to maximize surface contact area and to maximally distribute load. The side of the horizontal section facing away from the vertical section has a generally concave surface that is adapted to pivotally engage a center core of generally spherical shape. The lower part is preferably an inverted copy of the upper part so that its surfaces engage the center core and the lower adjacent vertebrae in a manner as described above with respect to the upper part. The vertical sections of each of the upper and lower parts have at least one fastener hole to enable a fastener such as a bone screw to fasten the respective part to a respective vertebra. The hole may be oversized, slotted or otherwise configured to allow relative movement of the screw and the part, thereby facilitating controlled movement of adjacent vertebrae.
[0014] An alternate preferred embodiment is directed to utilizing one of either the upper part of the lower part in a configuration as described above, but combining the center core with the other part for a total of two parts instead of three.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a front, perspective view of a preferred embodiment of the present invention.
[0016] FIG. 2 is a side view of the preferred embodiment as shown in FIG. 1 .
[0017] FIG. 3 is a front view of the preferred embodiment of FIG. 1 shown assembled to adjacent vertebrae.
[0018] FIG. 4 is a side view of the preferred embodiment of the present invention shown assembled to adjacent vertebrae.
[0019] FIG. 5 is a front view of a second preferred embodiment of a component of the present invention.
[0020] FIG. 6 is a side, cross-sectional view of a third embodiment of the present invention.
[0021] FIG. 7 is a side, cross-sectional view of a fourth embodiment of the present invention.
[0022] FIG. 8 is a perspective view of another preferred embodiment of a component of the present invention.
[0023] FIG. 9A is a top, partial cross-section view of a component according to an other embodiment of the present invention.
[0024] FIG. 9B is an exploded view of the component shown in FIG. 9A .
[0025] FIG. 10 is a bottom, schematic view of another component according to the present invention.
[0026] FIG. 11A is a cross-sectional, side view of another preferred embodiment assembly according to the present invention.
[0027] FIG. 11B is a side view of the assembly shown in FIG. 11A .
[0028] FIG. 12A is a schematic, side view of an assembly according to the present invention.
[0029] FIG. 12B is a schematic, front view of the assembly shown in FIG. 12A .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0030] A first embodiment assembly according to the present invention is described with respect to FIGS. 1-4 . An implant assembly ( 10 ) according to the present invention comprises an upper part ( 12 ), a lower part ( 14 ), and a center core ( 16 ). The upper part ( 12 ) comprises a vertical section front face ( 18 ), a vertical section rear face ( 20 ), a horizontal section top face ( 22 ), and a horizontal section bottom face ( 24 ). The lower part ( 14 ) comprises a vertical section front face ( 26 ), a vertical section rear face ( 28 ), a horizontal section top face ( 30 ), and a horizontal section bottom face ( 32 ). Each of the vertical sections of the upper part ( 12 ) and the lower part ( 14 ) comprise at least one fastener hole ( 34 , 36 ). Each hole ( 34 , 36 ) is adapted to receive a fastener ( 38 , 40 ) such as a bone screw.
[0031] The horizontal top face ( 22 ) of the upper part ( 12 ) and the horizontal bottom face ( 32 ) of the lower part ( 14 ) are each preferably convex in shape to match the anatomical shape of the end faces of adjacent vertebrae ( 42 , 44 ) for optimal load distribution. One or more teeth ( 46 , 48 ) or similar protrusions are provided to enhance grip of to bite into the end faces of the vertebrae. The opposite sides of the horizontal sections, namely the horizontal bottom face ( 24 ) of the upper part ( 12 ) and the horizontal top face ( 30 ) of the lower part ( 14 ), face each other and are generally concave shaped to privotally engage a center core ( 16 ) that is convex on upper and lower surfaces and, as such, may be generally spherically shaped. Depending on the specific dimensions of the concave and convex portions, as well as on any raised circumferential rims (not shown) that may be provided on the faces ( 24 , 30 ) or a flange (not shown) that may be provided on the center core ( 16 ), pivotal movement may be controlled to a certain degree. Similarly, predetermined sliding movement of the center core ( 16 ) relative to the upper and lower parts ( 12 , 14 ) may be introduced if desired by adjusting such dimensions and flange or rim features.
[0032] The bone screws ( 38 , 40 ) or fasteners may be of a known type having heads that are sized to adequately hold the parts ( 12 , 14 ) to adjacent vertebrae but that allow predetermined sliding movement within the holes ( 34 , 36 ) and/or that allow relative pivoting within the holes ( 34 , 36 ). These features allow predetermined movement or dynamization of an assembled vertebral section using the present invention system. As shown in the preferred embodiment, the holes ( 34 , 36 ) are oversized relative to the screw shafts to allow sliding and pivoting, and the screws ( 38 , 40 ) have semi-spherical heads. By selecting hole size and/or head shape, one or both of sliding and pivoting movement can be controlled or eliminated if desired.
[0033] As shown in FIG. 4 , more than two adjacent vertebrae ( 42 , 44 , 50 ) may receive adjacent assemblies ( 52 , 54 ) according to the present invention. This in because the offset allows a single vertebra to receive two assembly parts, thereby enabling the present invention assemblies to bridge adjacent vertebral spaces separated by only one vertebra. This is attributable to the offset or asymmetrical characteristic of positioning a vertical portion ( 56 ) offset from a vertical centerline of the assembly to have its vertical portion ( 56 ) be nested relative to the recessed portion ( 58 ). This is a significant advantage over known designs which do not leave adequate space to attach adjacent assemblies to a sequence of adjacent vertebrae. Such known designs cannot be installed to bridge successive vertebral spaces separated only one vertebra.
[0034] Implant assemblies according to the present invention are installed using procedural steps and techniques that are similar to current procedures and techniques used in implanting known cervical plates. Thus, an advantage of the present invention is that spine surgeons are already familiar with and skilled in the procedures and techniques needed to install the present invention system. The center core ( 16 ) can be made available in a variety of sizes and geometries that can be used with one or a few standard size upper and lower parts ( 12 , 14 ) thereby enabling the present invention to be presented as a modular system and minimizing inventory requirements. This provides advantages of versatility and cost efficiency not attained by known devices.
[0035] A second embodiment of the present invention assembly ( 100 ) is shown in FIG. 5 having an upper part ( 102 ) and a lower part ( 104 ) in which respective fastener holes ( 106 , 108 ) are elongated. Such elongation of the holes ( 106 , 108 ) may b e used for relieving stress by allowing relative movement of the upper or lower part ( 102 , 104 ) with respect to a fastener (not shown) which attaches the assembly ( 100 ) to bone structures. The elongated holes ( 106 , 108 ) may also provide versatility in positioning with respect to limited fastener positions during installation. It is understood that such elongated or slotted holes ( 106 , 108 ) may be provided on one or on both parts ( 104 , 106 ) in any of the preferred embodiments described herein.
[0036] Another embodiment of the invention, shown in FIG. 6 , is directed to an assembly ( 200 ) having an upper part ( 202 ) and a lower part ( 204 ). The upper part ( 202 ) is generally similar to the upper part ( 12 ) in the first preferred embodiment. The lower part ( 204 ) is comprised of a vertical front face ( 206 ), a vertical rear face ( 208 ), a horizontal lower face ( 210 ), and a horizontal upper face( 212 ). The horizontal upper face ( 212 ) has a convex or dome portion ( 214 ) which, effectively, combines the lower part ( 14 ) and center core ( 16 ) of the first embodiment. The upper part ( 202 ), the lower part ( 204 ), or both, may be of various sizes, preferably interchangeable for compatibility with a variety of other parts, to allow versatility in mating parts.
[0037] Another embodiment of the present invention, shown in FIG. 7 , is directed to an assembly ( 300 ) having upper and lower parts ( 302 , 304 ) generally similar to the upper and lower parts described in the earlier embodiments, but with flat, horizontal, opposing surfaces ( 306 , 308 ). The flat surfaces ( 306 , 308 ) are adapted to receive in a fixed manner inserts ( 310 , 312 ) which cooperate to form a moveable joint. For example, the upper insert ( 310 ) has a concave surface for receiving a dome ( 312 ) portion of the lower insert ( 312 ). Variations of the specific insert geometries are contemplated.
[0038] In each embodiment of the present invention described herein, while the upper are lower parts are presented as identical in the above embodiments, except for one having a concave surface adapted to mate with a corresponding concave surface, it is conceivable that in some circumstances, such as those described below, non-like upper and lower parts can be utilized together in a system. Thus, with respect to FIGS. 8-9 , another preferred embodiment is described herein and a component is referred to as a “first part” which could be used in a system with an identical “second part” or a non-like second part. Either part could be the upper or lower part depending on preference and conditions.
[0039] Thus, referring to FIGS. 8-9 ( 9 A and 9 B), a first part ( 400 ) has a generally vertical outward facing surface ( 402 ), a generally vertical inward facing surface ( 404 ), a generally horizontal interior surface ( 406 ), a generally horizontal exterior surface ( 408 ), a fastener hole ( 410 ), an approximately ninety degree bend region ( 412 ), an anterior side ( 414 ), a posterior side ( 416 ), a keel ( 418 ), and a sliding part ( 420 ). In the embodiment of FIGS. 8-9 , the first part ( 400 ) is installed as part of a spinal implant assembly in a manner such as that described above with respect to the upper and lower parts of the preferred embodiments previously described. The horizontal surfaces ( 406 , 408 ) are positioned in and intervertebral space and the vertical inward facing surface ( 404 ) contacts the anterior side of a vertebra. A bone faster or bone screw ( 422 ) passes through the hole ( 410 ) to secure the part ( 400 ) to the vertebra. Preferably, the bone screw ( 422 ) has a back-out prevention feature of any known type or of the type shown in FIG. 9 where a captive ring ( 424 ) resides in the hole ( 410 ) and is adapted to receive the head ( 426 ) of the bone screw ( 426 ) in a manner that causes the bone screw ( 424 ) to be held therein by an interference fit. The hole ( 410 ) may be slotted as shown in FIG. 8 to allow adjustment or to allow dynamic movement. The hole ( 410 ) and the screw head ( 426 ) may, as preferred, be provided with features (generally known) that enable pivotal movement or that restrict pivotal movement, depending on the desired application. The horizontal interior surface ( 406 ) may be provided with a keel ( 418 ) having a sharp edge ( 428 ) adapted to cut into the surface of a vertebral end face for stability. In the horizontal exterior surface ( 408 ), a sliding part ( 420 ) is provided. The sliding part ( 420 ) is one of a complementing pair of concave and convex surfaces. For illustration, in FIG. 8 there is shown a concave surface ( 430 ) which would slidingly and rotatably engage a complementing convex surface (not shown) on a second part (not shown) adapted to be mounted in the same intervertebral space and in contact with the opposing vertebra.
[0040] FIG. 10 is a view of a part ( 500 ) of the type that could be used in combination with the first part ( 400 ) of FIGS. 8-9 . The part ( 500 ) is like first part ( 400 ) in all respects except that it has as its sliding part ( 520 ) a convex surface ( 532 ) adapted to slidingly and rotatably engage the concave surface ( 430 ) of first part ( 400 ). Below when reference to a feature is made as “not visible in FIG. 10 ” it means, in this context, that a different view than FIG. 10 is needed to see that feature. Since the part is the same as that illustrated in FIGS. 8-9 but for the “sliding part ( 520 )”, additional views are not shown because they would be redundant. The part ( 500 ) has a generally vertical outward facing surface ( 502 ), a generally vertical inward facing surface (not visible in FIG. 10 ), a generally horizontal interior surface (not visible in FIG. 10 ), a generally horizontal exterior surface ( 508 ), a fastener hole (shown in dotted lines as 410 , but otherwise not visible in FIG. 10 ), an approximately ninety degree bend region ( 512 ), an anterior side ( 514 ), a posterior side ( 516 ), a keel (not visible in FIG. 10 ), and a sliding part ( 520 ). When selecting mating parts such as first part ( 400 ) and part ( 500 ) to be used together it would be preferable to select them with the vertical parts (i.e., 402 and 502 ) being offset to the same side so that they can nest as shown in and described with respect to FIG. 4 .
[0041] Another preferred embodiment is shown in FIGS. 11A-11B , FIG. 11A is shown in cross-section. In this embodiment, an assembly ( 600 ) of the type and for the purpose as described above with respect to preceding embodiments, has a first part ( 600 ) having a generally vertical outward facing surface ( 602 ), a generally vertical inward facing surface ( 604 ), a generally horizontal interior surface ( 606 ), a generally horizontal exterior surface ( 608 ), a fastener hole ( 610 ), an approximately ninety degree bend region ( 612 ), an anterior side ( 614 ), a posterior side ( 416 ), a keel ( 618 ), and a sliding part ( 620 ). A second part ( 601 ) has a generally vertical outward facing surface ( 603 ), a generally vertical inward facing surface ( 605 ), a generally horizontal interior surface ( 607 ), a generally horizontal exterior surface ( 609 ), a fastener hole ( 611 ), an approximately ninety degree bend region ( 613 ), an anterior side ( 615 ), a posterior side ( 617 ), a keel ( 619 ), and a sliding part ( 621 ).
[0042] The first part's sliding part ( 620 ) has a concave surface ( 622 ) adapted to slidingly and rotatably mate with a convex surface ( 621 ) on the second part ( 601 ). The first part's sliding part ( 620 ) has an angled sidewall first portion( 624 ) and an angled sidewall second portion ( 626 ) providing a geometry that blocks over-rotation among the first part ( 600 ) and second part ( 601 ) relative to each other, but that allows more freedom of rotation in the posterior direction than in the anterior direction, in accordance with natural movements of a patient's spinal column, particularly in the cervical region.
[0043] FIG. 12 illustrates, schematically, how a first part ( 700 ) intervertebral implant component according to present invention, can be used in cooperation with a non-like intervertebral component ( 702 ) of any type generally known that engages or cooperates with the first part ( 700 ) in a desirable and sufficient manner. For example, when two intervertebral assemblies ( 714 , 716 ) are applied to adjacent intervertebral spaces defined by three successive vertebrae ( 708 , 710 , 712 ), a first part ( 700 ) according to any one of the above-described present invention embodiments is paired with a non-like intervertebral component ( 702 ) such as one generally known or one that does not have a vertical component ( 718 , 720 ) of the type according to the present invention. This could be for any of a variety of reasons as determined by a surgeon. Likewise, a third part ( 704 ) according to the present invention is paired with a non-like fourth part ( 706 ). Due to the novel, offset vertical components ( 718 , 720 ) of the present invention parts ( 700 , 704 ), the vertical components nest as described with respect to the embodiment of FIG. 4 , thereby making optimal use of limited space on the anterior face ( 722 ) of the vertebra ( 710 ) in the middle of the three-vertebrae sequence.
[0044] The upper parts, lower parts and center core from any of the above-identified embodiments may be made from any one of or a combination of known materials of sufficient strength and surgical compatibility for surgical implants. These materials include, but are not limited to, titanium, steel, ceramic, Teflon®, nylon, polyethylene, and Cobalt Chromium Moly.
[0045] While the preferred embodiments of the present invention have been described, various modifications can be made without departing from the scope of the invention. | A system of reconstruction for a spinal joint is directed to a modular implant assembly that includes an upper part and a lower part. The upper and lower parts each comprise a unitary body having an approximately ninety degree bend defining vertical and horizontal components. Each vertical component has a fastener hole for attaching it to a bone segment using a bone fastener. The horizontal sections each have a complementary contact surfaces in order to transmit compressive load therebetween and to accommodate sliding and pivoting relative movement therebetween. The vertical sections of each of the upper and lower part are offset with respect to a vertical centerline so that successive assemblies bridging more than one adjacent vertebral space can have an upper part and a lower part according to the present invention coexist on a single vertebra in a space-efficient manner wherein the vertical sections nest spatially. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
Not Applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
Not Applicable
BACKGROUND OF THE INVENTION
1. Field of the Invention
In some embodiments this invention relates to implantable medical devices, their manufacture, and methods of use. More particularly some embodiments of this invention relate to delivery systems for intravascular stents, such as catheter systems of all types, which are utilized in the delivery of such devices.
2. Description of the Related Art
A stent is a medical device introduced to a body lumen and is well known in the art. Typically, a stent is implanted in a blood vessel at the site of a stenosis or aneurysm endoluminally, i.e. by so-called “minimally invasive techniques” in which the stent in a radially reduced configuration is delivered by a stent delivery system or “SDS” to the site where it is required.
In some circumstances however, a stent or other medical device which is tracked through body vessels ultimately is not implanted and needs to be removed. Non-implantation may result from a number of causes including but not limited to lack of success in reaching the intended target lesion. When the stent will not be implanted its removal becomes necessary. Stent removal can involve both pulling the stent back in the opposite direction of its insertion as well as possibly pushing the stent further into a body vessel. The already tracked device at this point however could have experienced flexing which can cause flaring at one or more ends of the stent. This can result in the flared end(s) of the stent catching on portions of the body vessel upon further movement in either direction and thus cause embolization or vessel damage.
The art referred to and/or described above is not intended to constitute an admission that any patent, publication or other information referred to herein is “prior art” with respect to this invention. In addition, this section should not be construed to mean that a search has been made or that no other pertinent information as defined in 37 C.F.R. §1.56(a) exists.
All US patents and applications and all other published documents mentioned anywhere in this application are incorporated herein by reference in their entirety.
Without limiting the scope of the invention a brief summary of some of the claimed embodiments of the invention is set forth below. Additional details of the summarized embodiments of the invention and/or additional embodiments of the invention may be found in the Detailed Description of the Invention below.
A brief abstract of the technical disclosure in the specification is provided as well only for the purposes of complying with 37 C.F.R. 1.72. The abstract is not intended to be used for interpreting the scope of the claims.
BRIEF SUMMARY OF THE INVENTION
Some embodiments of the invention are directed to features that can be incorporated into catheters in general, and particularly stent delivery systems (SDS) to facilitate proximal and distal (if desired) edge protection to the stent in the event of aborting stent delivery and/or deployment. This invention contemplates a number of embodiments where any one, any combination of some, or all of the embodiments can be incorporated into a stent delivery system and/or a method of use.
At least one of the embodiments of the inventive concept is directed to an SDS having an outer neck which extends distally into the balloon cone or distally into the balloon working region. The inventive concept also contemplates at least one embodiment directed to an SDS having a tapered outer neck. At least one embodiment encompassed by the inventive concept is directed to an SDS having one or more aperture extending through the side walls of the outer neck. In at least one embodiment these apertures facilitate the inflation or deflation of a balloon.
One or more embodiments of the inventive concept are directed to a second reinforcing member located at the distal end of the SDS which protrudes into the distal cone of the balloon, protrudes into the distal side of the working region of the balloon, has one or more inflating or deflating apertures, has a tapered shape, or any combination thereof.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
The invention is best understood from the following detailed description when read in connection with accompanying drawings, in which:
FIG. 1 is an image of a Stent Delivery System (SDS) in which the region immediately proximal to the crimped stent has been edge protected to facilitate easy removal from a body vessel.
FIG. 2 is an image of an SDS in which the region immediately proximal to the crimped stent has been edge protected and has longitudinal slots.
FIG. 3 is an image of an SDS in which the region immediately proximal to the crimped stent has been edge protected and the outer lumen has circumferential slots.
FIG. 4 is an image of an SDS in which both the region immediately proximal to the crimped stent and the region immediately distal to the crimped stent have been edge protected.
FIG. 5 is an image of an SDS in which the region immediately proximal to the crimped stent has been edge protected and the outer lumen has a plurality of apertures.
FIG. 6 is an image of an SDS in which the region immediately proximal to the crimped stent has been edge protected and the outer lumen has a plurality of longitudinally displaced slots.
FIG. 7 is an image of an SDS in which the region immediately proximal to the crimped stent has been edge protected, the outer lumen has a plurality of apertures, and the outer lumen has a distally widened conical shape.
FIG. 8 is an image of an SDS in which the region immediately proximal to the crimped stent has been edge protected, the outer lumen has a plurality of apertures, and the outer lumen has a proximally widened conical shape.
FIG. 9 is an image of an SDS after the balloon has been inflated in which both the region immediately proximal to the crimped stent and the region immediately distal to the crimped stent have been edge protected.
FIG. 10 is an image of an SDS with a common circumferential surface.
FIG. 11 is an image of an SDS with an outwardly protruding balloon.
FIG. 12 is an image of an SDS with an outwardly folded balloon.
DETAILED DESCRIPTION OF THE INVENTION
The invention will next be illustrated with reference to the figures wherein the same numbers indicate similar elements in all figures. Such figures are intended to be illustrative rather than limiting and are included herewith to facilitate the explanation of the apparatus of the present invention. For the purposes of this disclosure, like reference numerals in the figures shall refer to like features unless otherwise indicated. Depicted in the figures are various aspects of the invention. Elements depicted in one figure may be combined with, or substituted for, elements depicted in another figure as desired.
Referring now to FIG. 1 there is shown a stent delivery system (SDS) ( 1 ) in an unexpanded configuration. The SDS ( 1 ) comprises an unexpanded stent ( 4 ) crimped about a catheter or shaft ( 3 ). The stent ( 4 ) has a proximal edge ( 5 ) and a distal edge ( 11 ) and is constructed to have a tubular structure with a diameter ( 20 ). The diameter ( 20 ) has a first magnitude which permits intraluminal delivery of the tubular structure into the body vessel passageway, and a second expanded and/or deformed magnitude (as shown in FIG. 9 ) which is achieved upon the application of a radially, outwardly expanding force.
The SDS ( 1 ) also comprises an outer tube or shaft ( 34 ) which defines an outer lumen. Within the outer tube ( 34 ) is a portion of an inner tube ( 14 ). The inner tube ( 14 ) defines an inner lumen. A portion of the inner tube ( 14 ) extends beyond the outer tube ( 34 ) and the crimped stent ( 4 ) is disposed about at least a portion of the inner tube ( 14 ). Sandwiched between the stent ( 4 ) and the portion of the inner tube ( 14 ) extending out of the outer tube ( 34 ) is a portion of an expansion balloon ( 6 ). The expansion balloon ( 6 ) extends longitudinally beyond both edges ( 5 , 11 ) of the stent ( 4 ) and is functionally engaged to both the outer tube ( 34 ) and the inner tube ( 14 ) forming a substantially fluid tight seal between the outer and inner lumens. The portion of the balloon ( 6 ) engaged to the outer tube ( 34 ) is the waist ( 7 ) of the balloon. At times, positioned at or near the longitudinal position on the SDS ( 1 ) adjacent to the proximal end of either the balloon ( 6 ) or the stent ( 4 ) are one or more marker bands ( 9 ). The marker band ( 9 ) can contain a radiopaque material used for following the progress of the SDS ( 1 ) through the body vessel and/or can be used to block off unwanted longitudinal movement of the stent ( 4 ) along the catheter ( 3 ). Although FIGS. 1-12 illustrate the marker bands ( 9 ) as cylindrically trapezoidal, it is contemplated by the inventive concept that they be rectangular or in any other shape.
The SDS ( 1 ) of FIG. 1 is shown in its expanded state in FIG. 9 . During a stent implantation, the SDS ( 1 ) is positioned adjacent to an implantation site of a body vessel and fluid is injected through the outer lumen ( 34 ) into the balloon ( 6 ). The injected fluid causes the balloon ( 6 ) to radially expand. A balloon ( 6 ) will typically have a proximal end region ( 15 ), a distal end region ( 17 ) and a working region ( 19 ) extending between the proximal end ( 15 ) and distal end ( 17 ) regions. As the balloon ( 6 ) expands, the working region ( 19 ) in turn expands the stent ( 4 ) which when fully expanded to the second magnitude diameter ( 20 ), is then implanted at the implantation site.
In at least one embodiment, the proximal and distal end regions ( 15 , 17 ) are respectively proximal and distal cones ( 15 , 17 ). The proximal and distal cones ( 15 , 17 ) comprise those portions of the balloon ( 6 ) which longitudinally spans from the waist ( 7 ) to a portion of the working region ( 19 ) which is both closest to the waist ( 7 ) and most distant from the inner lumen ( 14 ) when in the second expanded state. The cones ( 15 , 17 ) are so named because when expanded, those portions of the balloon ( 6 ) progressively expand away from the catheter ( 3 ) in a tapered or conical manner.
On some occasions however, the stent implantation will be aborted and the stent ( 4 ) must be removed from either the implantation site or from whichever body vessel the SDS ( 1 ) has tracked the stent ( 4 ) within. FIG. 1 illustrates at least one embodiment of the present invention where the end ( 5 ) of the stent ( 4 ) is reinforced by the extension of the outer neck ( 35 ) to a position considerably within the proximal balloon cone ( 15 ). The outer neck ( 35 ) comprises a portion of the outer tube ( 34 ) immediately proximal to the crimped stent ( 4 ). The outer neck ( 35 ) has two regions, a second region ( 22 ) and a third region ( 23 ) which is distal to the second region ( 22 ). The outer neck ( 35 ) is engaged to the balloon waist ( 7 ) at the second region ( 22 ). Both regions of the outer neck ( 35 ) are narrower than the main portion or first region ( 21 ) of the outer tube ( 34 ).
As illustrated in FIG. 1 , the protrusion of the outer neck ( 35 ) into the balloon cone ( 15 ) provides reinforcement to the SDS ( 1 ) by limiting the flexibility of the unexpanded balloon ( 6 ). This decrease in balloon ( 6 ) flexibility reduces the amount the stent ( 4 ) can be bent when being tracked in any direction through body vessels while disposed about the balloon ( 6 ). By reducing the amount that the stent ( 4 ) can bend, it becomes less likely that the ends ( 5 , 11 ) of the stent ( 4 ) will flex and flare outwards and snag or catch onto a wall of a body vessel and potentially cause damage or embolization. The reinforcement also makes it less likely that compressive forces encountered while tracking the SDS ( 1 ) through body vessels would deform the balloon and prevent proper inflation
The protrusion of the outer neck ( 35 ) into the cone ( 15 ) has other benefits as well. The reinforcement provided by the protrusion, helps the SDS ( 1 ) resist bending in response to torque from levering forces applied along the length of the SDS ( 1 ) by movements of the mass at the end of the guide tip ( 29 ). By reducing bending of the SDS ( 1 ), misaligning of the balloon ( 6 ) and increased the flaring of the stent ( 4 ) is avoided. In addition, the protrusion of the outer neck ( 35 ) into the cone ( 15 ) also facilitates balloon ( 6 ) inflation. This is because the inflating fluid fed into the balloon ( 6 ) exits the third region ( 23 ) much closer to the working region ( 19 ) of the balloon preventing excessive accumulation of fluid in the cone ( 15 ) and providing more inflating pressure against the working region ( 19 ). The protrusion also protects the balloon material while it is folded onto the SDS ( 1 ) and while the stent ( 4 ) is crimped to the SDS ( 1 ). Lastly, the reinforcement makes the balloon ( 6 ) better able to avoid deformation in response to interacting with the force of the impact between the expanding stent ( 4 ) and the walls of the body vessel at the site of the stenosis.
There are a number of embodiments according to which the outer neck ( 35 ) can protrude into the cones ( 15 ). In at least one embodiment as shown in FIG. 4 , the outer neck ( 35 ) extends radially past the marker band ( 9 ). In at least one embodiment, the outer neck ( 35 ) extends longitudinally past the marker band ( 9 ) to a position longitudinally closer to the stent ( 94 ). Alternatively the marker band ( 9 ) can be closer to the stent than the outer neck ( 35 ). In at least one embodiment as shown in FIGS. 4 and 9 a second reinforcing member ( 40 ) analogous to the protruding outer neck ( 35 ) can also be positioned adjacent to the distal end of the stent ( 11 ) and protrude into the distal cone ( 17 ) providing similar reinforcing properties at the distal end of the SDS ( 1 ).
In at least one embodiment as illustrated in FIG. 12 , the outer neck ( 35 ) can longitudinally protrude so far into (or past) the cone ( 15 ) that it longitudinally extends to a position substantially flush with the edge of the stent ( 4 ). In at least one embodiment, the flush positioning causes a balloon bulge ( 24 ) to abut the stent end ( 5 ) which extends further radially than the stent end ( 5 ). This more radial extension causes the bulge ( 24 ) to block any radially vectored impacts or interactions between the stent edge ( 5 ) and body vessels. In addition, positioning the outer neck ( 35 ) almost flush against the stent end ( 5 ) can wedge the stent ( 4 ) into place and pinion the stent to resist any outward flaring caused by torque being applied to the stent ( 4 ).
Referring now to FIG. 10 there is shown at least one embodiment of the inventive concept directed to an SDS ( 1 ) which can remove a non-implanted stent ( 4 ). In this SDS ( 1 ), the main portion ( 21 ) of the outer tube ( 34 ), the balloon waist ( 7 ) about the second region ( 22 ), and the crimped stent ( 4 ) are all sized such that their outer surfaces share a substantially similar circumference ( 12 ) relative to an axis ( 16 ) extending longitudinally through the center of the SDS ( 1 ). This common circumference ( 12 ) provides the SDS ( 1 ) a generally uniform surface facing the body vessel the SDS is tracked through. This uniform surface limits the likelihood of a portion of the SDS ( 1 ) becoming snagged against a portion of the body vessel whether the SDS is being moved in a proximal or distal direction.
As shown in FIG. 1 , the inventive concept also contemplates at least one embodiment in which a gap ( 8 ) between the proximal edge ( 5 ) of the stent ( 4 ) and the distal end of the third region ( 23 ) of the outer neck ( 35 ) helps protects against harmful contact between the SDS ( 1 ) and a body vessel it is being tracked through. Within this gap ( 8 ), the material of the balloon ( 6 ) flows radially and longitudinally outward from beneath the stent ( 4 ) to a position outside of the outer neck ( 35 ). The folded balloon material within the gap will have a diameter smaller than that of the stent ( 4 ). This outward flowing balloon material wraps a portion of the balloon ( 6 ) around the proximal edge ( 5 ) of the stent ( 4 ) reducing the exposure of any irregular surface of the stent edge ( 5 ) to the body vessel the SDS ( 1 ) is being tracked through.
The gap ( 8 ) is properly spaced to accommodate balloon materials of a specific thickness such that the outer surface of the balloon ( 6 ) curves or arcs along an optimal path. In at least one embodiment illustrated in FIG. 1 , the balloon material curves out from beneath the stent ( 4 ) to a position which is substantially flush and smooth with the common circumferential perimeter ( 12 ) without any bulging of either the stent ( 4 ) or the balloon ( 6 ).
In at least one embodiment illustrated in FIG. 11 , the gap ( 8 ) is spaced such that it causes the outer surface of the balloon ( 6 ) to have an outward bulge ( 24 ) which protrudes beyond the circumferential perimeter ( 12 ) of the stent ( 4 ). Because the outward bulge ( 24 ) protrudes further in a radial direction than the stent end ( 5 ), the bulge ( 24 ) prevents the stent end ( 5 ) from coming into contact with any of the body vessels when the SDS ( 1 ) impacts against body vessels it is being tracked through. As illustrated in FIG. 4 , at least one embodiment of the inventive concept is directed to a distal gap ( 8 ) between the distal end of the stent ( 11 ) and the proximal side of a second reinforcing member ( 40 ). The inventive concept contemplates a distal gaps as that of FIG. 4 in which there is no bulge protruding further in a radial direction than the stent end ( 5 ) as well as a spaced distal gap ( 8 ) allowing for an arced bulge similar to that of FIG. 11 at the distal side of the stent ( 4 ).
Referring now to FIGS. 7 and 8 there is shown an SDS ( 1 ) with a tapered outer neck ( 35 ). As FIG. 7 shows, at least a portion of the outer neck is tapered or conically shaped with a wider proximal area. In the alternative as shown in FIG. 8 , at least a portion of the outer neck ( 35 ) is tapered with a wider distal area. The inventive concept also contemplates non-linear outer necks ( 35 ) including but not limited to outer necks ( 35 ) which are arced, slanted, waved, irregularly shaped, or which have one or more angled portions between distal and proximal ends with substantially similar or the same circumferences, and any combination thereof. In at least one embodiment, the angling of the tapering in the outer neck ( 35 ) reinforces the stent edge(s) by being directed opposite to the flare causing flexing that the stent ( 1 ) encounters. In at least one embodiment, a second reinforcing member at the distal side of the SDS ( 1 ) is similarly tapered.
FIGS. 2 , 3 , 5 , 6 , 7 , and 8 illustrate SDSs ( 1 ) in which there are one or more cavities or apertures ( 18 ) extending through the wall of the outer necks ( 35 ). Because these illustrations disclose details of at least the outer surface of the outer neck ( 35 ), they do not explicitly show the inner tube ( 14 ) or guide wire ( 33 ) passing through the outer neck ( 35 ). It would be clear however, to practitioners of ordinary skill in the art however that these illustrations disclose embodiments in which one, both, or none, of the guide wire ( 33 ) and the inner lumen ( 14 ) pass through the outer neck ( 35 ) of the outer tube ( 34 ). Similarly, the inventive concept contemplates embodiments in which the various apertures ( 18 ) of FIGS. 2 , 3 , 5 , 6 , 7 , and 8 are also present on the distal side of the SDS ( 1 ) positioned on a second reinforcing member (such as ( 40 ) in FIG. 4 ) analogous to the outer neck ( 35 ).
Sometimes an SDS ( 1 ) having an already inflated or partially inflated balloon ( 6 ) needs to be removed. FIG. 2 illustrates at least one embodiment in which an SDS ( 1 ) has at least one aperture ( 18 ) through which the fluid which previously inflated the balloon ( 6 ) can be drained or suctioned through. These apertures ( 18 ) can be one or more rectangular slots (as shown in FIG. 2 ) as well as circles, ellipse, squares, or any other known shape in the art. Similarly the apertures 15 can have their opening extend in a longitudinal manner (as in FIG. 2 ), in a circumferential manner (as in FIG. 3 ), diagonally, or in any possible combination of longitudinal, diagonal, or circumferential extension.
The number of the apertures ( 18 ), their size, and their distribution across the outer neck ( 35 ) can vary depending on the desired rate of fluid flow. In at least one embodiment, at least one aperture ( 18 ) extends longitudinally across a majority of the length of the outer neck ( 35 ). Similarly, in at least one embodiment, at least one aperture ( 18 ) extends circumferentially across a majority of the circumference of the outer neck ( 35 ). Also, in at least one embodiment one or more of the apertures ( 18 ) have one way openings or valves which reduce or prevent fluid flow while the balloon ( 6 ) is either being inflated or deflated, but allows fluid flow when the balloon ( 6 ) is being respectively deflated or inflated. Embodiments in which the end of the aperture ( 18 ) facing the outer lumen may have a different width or circumference than the end of the aperture ( 18 ) on the outer surface of the outer neck ( 35 ) and/or of any point along the length of the aperture ( 18 ) between these two ends are contemplated by this inventive concept. In addition, embodiments in which the apertures ( 18 ) facilitate a balloon ( 18 ) to be inflated more rapidly or easily than to be deflated or vice versa are contemplated by this inventive concept.
The apertures ( 18 ) can be of particular utility during the deflation of a balloon ( 6 ). During deflation, because the apertures ( 18 ) are positioned within the cones ( 15 , 17 ) they can directly drain or suction fluid from the cones ( 15 , 17 ). This helps to remove fluid that otherwise does not drain well from the narrow confines of the proximal and distal tips of the cones ( 15 , 17 ). The drainage or suction provided by the apertures combined with the drainage or suction that the distal end of the third region ( 23 ) applies to the working region ( 19 ) assures that fluid is effectively drained from all portions of the balloon ( 6 ).
In at least one embodiment, as illustrated in FIG. 3 , at least one aperture ( 18 ) is positioned on the outer neck ( 35 ) longitudinally adjacent to the tip of the proximal cone ( 15 ) which is located at the waist-cone transition point ( 39 ). Because the tip of the cone ( 15 ) is so narrow it is a harder location to apply a suction force to and it retains fluid with a greater surface tension. The positioning of at least one aperture ( 18 ) at the waist-cone transition point ( 39 ) allows for targeted drainage from the tip of the cone. In at least one embodiment, there are at least two apertures located on opposite sides of the outer neck ( 35 ).
In some embodiments the stent, the SDS, or other portion of an assembly may include one or more areas, bands, coatings, members, etc. that is (are) detectable by imaging modalities such as X-Ray, MRI, ultrasound, etc. In some embodiments at least a portion of the coating of the stent and/or adjacent assembly is at least partially radiopaque.
In addition, any coating can also comprise a therapeutic agent, a drug, or other pharmaceutical product such as non-genetic agents, genetic agents, cellular material, etc. Some examples of suitable non-genetic therapeutic agents include but are not limited to: anti-thrombogenic agents such as heparin, heparin derivatives, vascular cell growth promoters, growth factor inhibitors, Paclitaxel, etc. Where an agent includes a genetic therapeutic agent, such a genetic agent may include but is not limited to: DNA, RNA and their respective derivatives and/or components; hedgehog proteins, etc. Where a therapeutic agent includes cellular material, the cellular material may include but is not limited to: cells of human origin and/or non-human origin as well as their respective components and/or derivatives thereof. Where the therapeutic agent includes a polymer agent, the polymer agent may be a polystyrene-polyisobutylene-polystyrene triblock copolymer (SIBS), polyethylene oxide, silicone rubber and/or any other suitable substrate. It will be appreciated that other types of coating substances, well known to those skilled in the art, can be applied to the stent as well.
In some embodiments at least a portion of the stent is configured to include one or more mechanisms for the delivery of a therapeutic agent. Often the agent will be in the form of a coating or another layer (or layers) of material placed on a surface region of the stent, which is adapted to be released at the site of the stent's implantation or areas adjacent thereto.
This completes the description of the preferred and alternate embodiments of the invention. The above disclosure is intended to be illustrative and not exhaustive. This description will suggest many variations and alternatives to one of ordinary skill in this art. The various elements shown in the individual figures and described above may be combined, substituted, or modified for combination as desired. All these alternatives and variations are intended to be included within the scope of the claims where the term “comprising” means “including, but not limited to”.
Further, the particular features presented in the dependent claims can be combined with each other in other manners within the scope of the invention such that the invention should be recognized as also specifically directed to other embodiments having any other possible combination of the features of the dependent claims. For instance, for purposes of claim publication, any dependent claim which follows should be taken as alternatively written in a multiple dependent form from all prior claims which possess all antecedents referenced in such dependent claim if such multiple dependent format is an accepted format within the jurisdiction (e.g. each claim depending directly from claim 1 should be alternatively taken as depending from all previous claims). In jurisdictions where multiple dependent claim formats are restricted, the following dependent claims should each be also taken as alternatively written in each singly dependent claim format which creates a dependency from a prior antecedent-possessing claim other than the specific claim listed in such dependent claims below. | A system to deliver or remove an inflation expandable stent in a body vessel. The system avoids causing damage or embolisms to a body vessel it is traversing by restraining the edges of the stent from scraping against the walls of the body vessel. The edges are restrained by balloon folds, compressive wedging, and angled reflective resistance. In addition the device can also inflate or deflate the balloon more efficiently. | 0 |
FIELD
This disclosure pertains to reflective elements (reflective mirrors) that are especially suitable for use in “X-ray” optical systems. By “X-ray” is meant not only the conventional “hard” X-ray wavelengths of the electromagnetic spectrum but also the so-called “soft X-ray” (also termed “extreme ultraviolet” or EUV) wavelengths. More specifically, the disclosure pertains to multilayer-film-coated mirrors that can be used in any of various X-ray optical systems such as X-ray microscopes, X-ray analysis equipment, and X-ray exposure (microlithography) apparatus.
BACKGROUND
As the density of active-circuit elements in microelectronic devices (e.g., integrated circuits, displays, and the like) has continued to increase with corresponding decreases in the size of active-circuit elements in such devices, the resolution limitations of optical microlithography have become apparent. To obtain better resolution of circuit elements, especially such elements having a width of 0.15 micrometer or less, increasing attention has been directed to the development of a practical “next generation” microlithography technology.
A key candidate for next-generation microlithography exploits the short wavelengths of X-ray radiation. For example, EUV radiation is in the wavelength range of 11 to 14 nm, which is substantially shorter than the 157-nm wavelength representing the shortest achievable wavelength used in the deep UV radiation used in conventional optical microlithography. These shorter wavelengths in the X-ray portion of the electromagnetic spectrum offer tantalizing prospects of substantially improved pattern-element resolution (e.g., 70 nm or less) in microlithography. See, e.g., Tichenor et al., Transactions SPIE 2437:292 (1995).
The complex refractive index “n” of substances in the wavelength range of X-rays is expressed as n=1−δ−ik (wherein δ and k are complex numbers). The imaginary part k of the refractive index expresses X-ray absorption. Since δ and k are both considerably less than 1, the refractive index in this wavelength range is extremely close to 1. Consequently, optical elements such as conventional lenses cannot be used. Reflective optical elements, on the other hand, are practical and currently are the subject of substantial research and development effort.
From most surfaces, X-rays exhibit useful reflection only at oblique angles of incidence. In other words, the reflectivity of X-rays is extremely low at angles of incidence less than the critical angle θ c of total reflection, which is about 20° at a wavelength of 10 nm. Angles greater than θ c exhibit total reflection. Hence, many conventional X-ray optical systems are so-called “oblique-incidence” systems in which the X-radiation is incident at angles greater than θ c to the reflective surfaces in the optical systems. (The angle of incidence is the angle formed by the propagation axis of an incident beam relative to a line normal to the surface at which the propagation axis is incident.)
It has been found that multilayer-film mirrors exhibit high (albeit not total) reflectivity to X-radiation. The multilayer coating typically comprises several tens to several hundreds of layers. The layers are of materials exhibiting the highest available boundary-amplitude reflectivity. The thickness of each layer is established based on light-interference theory so as to achieve alignment of the phases of light waves reflected from the various layers. Multilayer-film mirrors are formed by alternately laminating, on a suitable substrate, a first substance of which the difference between its refractive index in the X-ray wavelength band to be used and its refractive index (n=1) in a vacuum is relatively large and a second substance of which this difference is relatively small. Conventional materials satisfying these criteria and exhibiting good performance are tungsten/carbon and molybdenum/carbon composites. These layers are usually formed by thin-film-formation techniques such as sputtering, vacuum deposition, CVD, etc.
Since multilayer-film mirrors also are capable of reflecting X-radiation at low angles of incidence (including perpendicularly incident X-radiation), these mirrors can be incorporated into X-ray optical systems exhibiting lower aberrations than exhibited by conventional oblique-incidence X-ray optical systems.
A multilayer-film mirror exhibits a wavelength dependency in which strong reflection of incident X-radiation is observed whenever Bragg's equation is satisfied. Bragg's equation is expressed as 2d sin(θ′)=nλ, wherein d is the period length of the multilayer coating, θ′ is the angle of incidence measured from the incidence plane (i.e., π/2−θ), and λ is the X-ray wavelength. Under conditions satisfying Bragg's equation, the phases of the reflected waves are aligned with each other, thereby enhancing reflectivity of the surface. For maximal reflectivity, the variables in the equation are selected so that the equation is fulfilled.
Whenever the multilayer coating of an X-ray mirror comprises alternating layers of molybdenum (Mo) and silicon (Si), the mirror exhibits high reflectivity at the long-wavelength side of the L-absorption end of silicon (i.e., at 12.6 nm). Thus, a multilayer-film mirror exhibiting high reflectivity (over 60% at direct incidence, θ=0°) at λ≈13 nm can be prepared with relative ease. As a result, Mo/Si multilayer-film mirrors are the currently most promising mirror configuration for use in reduction/projection microlithography performed using soft X-ray (EUV) radiation. This type of microlithography is termed extreme ultraviolet lithography (EUVL).
Whereas Mo/Si multilayer-film mirrors exhibit high reflectivity, as discussed above, their performance depends upon the wavelength of incident radiation and upon the angle of incidence, as indicated by Bragg's equation. Especially with curved multilayer-film-coated mirror surfaces, the angle of incidence of an X-ray beam differs at various points on the surface of such a mirror used in an illumination-optical system or a projection-optical system of an EUVL system. The difference in incidence angle over the mirror surface can range from several degrees to several tens of degrees. Consequently, whenever a multilayer film is formed with a uniform thickness over the entire surface of the mirror substrate, differences in reflectivity at the mirror surface will be evident as a result of the differences in the angle of incidence.
FIG. 6 is a graph showing a theoretical relationship of reflectivity to the angle of incidence of a multilayer-film mirror having a period length of 69 Å, a lamina count of 50 layer pairs, and an incident-light wavelength of 13.36 nm. The abscissa is angle of incidence and the ordinate is reflectivity. The solid-line curve denotes reflectivity of s-polarized light and the dotted line denotes reflectivity of non-polarized light. The period length is the total thickness of one pair of layers (i.e., in the case of a Mo/Si multilayer coating, one Mo layer with its adjacent Si layer). The ratio of the thickness of a single Mo layer to the period length is denoted Γ; in this example Γ is constant at 0.35. As can be seen from FIG. 6, reflectivity changes with the angle of incidence. Reflectivity is nearly 74% at a 0° angle of incidence, and decreases to less than 60% at a 110° angle of incidence. This represents a greater than 10% drop in reflectivity.
A conventional countermeasure to the reflectivity drop noted above involves providing the thickness of the multilayer coating with a distribution that changes over the mirror surface in a manner serving to offset the change in reflectivity. Thus, light of a specified wavelength is reflected with high reflectivity at the various angles of incidence characteristic of various respective points on the reflective surface.
For example, FIG. 7 is a graph showing the relationship of the period length and of total film thickness (period length×number of layer pairs) at which reflectivity is highest for an incident λ=13.36 nm versus the angle of incidence. The abscissa is angle of incidence, the left-hand ordinate is period length, and the right-hand ordinate is total film thickness (Γ=0.35). As can be seen in FIG. 7, the period length and total film thickness at which reflectivity is highest are approximately 68.28 Å and 3413 Å (50 layer pairs), respectively, whenever the angle of incidence is 0°. Whenever the angle of incidence is 10°, the period length and total film thickness at which reflectivity is highest are approximately 69.31 Å and 3466 Å (50 layer pairs), respectively. Consequently, in order for reflectivity to be at its highest at the various angles of incidence, it is necessary to make the period length approximately 1 Å larger, at points at which the angle of incidence is about 10°, than at points at which the angle of incidence is about 0°. Now, Mo/Si multilayer coatings on EUV-reflective multilayer-film mirrors generally comprise 50 layer pairs. Locally increasing the period length on a multilayer coating as summarized above would create a difference of 4.7 nm in the total film thickness of the multilayer coating, which would impose a corresponding change in the surface profile of the multilayer-film mirror. Since the magnitude of this change exceeds what can be tolerated from the standpoint of wavefront aberration of light reflected from the mirror, such changes can significantly deteriorate the optical performance of an EUV optical system including such a mirror.
SUMMARY
In view of the shortcomings of conventional multilayer-film mirrors as summarized above, the present invention provides, inter alia, multilayer-film mirrors that exhibit high reflectivity to incident X-radiation, independently of the angle of incidence and without deteriorating optical performance of the mirror. The invention also provides X-ray optical systems including such multilayer-film mirrors.
According to a first aspect of the invention, multilayer-film mirrors are provided that comprise a mirror substrate and a multilayer film on a surface of the mirror substrate. An embodiment of the multilayer film is configured so as to render the surface reflective to one or more selected wavelengths of incident X-ray light (e.g., hard X-ray light or “soft” X-ray light such as extreme ultraviolet (EUV) light). The multilayer film is formed of alternating superposed layers of a first and a second material arranged as multiple layer pairs superposed on the surface. The first material has a relatively large difference between its refractive index for X-ray light and its refractive index in a vacuum, and the second material has a relatively small difference between its refractive index for X-ray light and its refractive index in a vacuum. Each layer of the first material in the multilayer film has a respective thickness. In at least one of the layer pairs, a ratio (Γ) of the thickness of the respective layer of the first material to a thickness of the layer pair has a variable distribution over at least a portion of the surface.
In the multilayer-film mirror summarized above, Γ can vary with changes in angle of incidence of incident radiation over at least a portion of the surface. By varying Γ in this manner, maximal reflectivity can be obtained at each point on the reflective surface, corresponding to the respective angle of incidence at each point. For example, Γ can decrease with corresponding increases in angle of incidence of incident radiation over at least a portion of the surface. Generally, the angle of incidence is greater at the perimeter of a mirror than at the center of the mirror. Hence, by decreasing F at regions where the angle of incidence is great, high reflectivity can be achieved at such regions as well as at, for example, the center of the mirror.
By way of example, the first material can comprise molybdenum, which is especially suitable for a multilayer-film mirror reflective to incident EUV light. For certain wavelengths of EUV light, the first material can include ruthenium. Also for EUV light, the second material can comprise silicon.
In another embodiment the distribution of Γ is stepped over at least a portion of the surface. In this configuration, each step corresponds to a respective range of angle of incidence of radiation incident to the surface.
In another embodiment the distribution of Γ is continuous over at least a portion of the surface. In this distribution, Γ varies with respective angles of incidence of radiation incident to the surface. Typically, the layer pairs have a period length. The distribution of Γ can be continuous over a first portion of the surface in which angle of incidence of light incident to the surface is within a respective range and the period length is constant. In a second portion of the surface outside the first portion, Γ can be constant while the period length is increased. Alternatively, the distribution of Γ can be continuous over the surface, wherein the period length changes continuously over the surface.
According to another aspect of the invention, optical systems are provided that comprise any of the various embodiments of multilayer-film mirrors such as those summarized above. The optical systems can be configured as, for example, X-ray optical systems such as EUV optical systems.
According to yet another aspect of the invention, optical elements are provided that are reflective to incident X-ray light. An embodiment of such an optical element comprises a mirror substrate and a multilayer film on a surface of the mirror substrate. The multilayer film is configured as summarized above. The optical element can be, for example, a multilayer-film mirror or a reflective reticle. One or more such optical elements can be incorporated into, for example, an X-ray optical system such as an X-ray lithography tool.
According to yet another aspect of the invention, methods are provided for producing a multilayer-film mirror. In an embodiment of such a method, a surface of a mirror substrate is configured to be a reflective surface. On the reflective surface, a multilayer-film coating is formed by applying alternating superposed layers of a first and a second material arranged as multiple layer pairs superposed on the reflective surface. The first material has a relatively large difference between its refractive index for X-ray light and its refractive index in a vacuum, and the second material having a relatively small difference between its refractive index for X-ray light and its refractive index in a vacuum. Each layer of the first material in the multilayer film has a respective thickness. In at least one of the layer pairs, a ratio (Γ) of the thickness of the respective layer of the first material to a thickness of the layer pair has a variable distribution over at least a portion of the surface.
The multilayer-film coating can be formed such that Γ varies with changes in angle of incidence of incident radiation over at least a portion of the surface. Alternatively, the multilayer-film coating can be formed such that Γ decreases with corresponding increases in angle of incidence of incident radiation over at least a portion of the surface. Further alternatively, the multilayer-film coating can be formed such that the distribution of Γ is stepped over at least a portion of the surface, wherein each step corresponds to a respective range of angle of incidence of radiation incident to the surface. Yet further alternatively, the multilayer-film coating can be formed such that the distribution of Γ is continuous over at least a portion of the surface, wherein, in the distribution, Γ varies with respective angles of incidence of radiation incident to the surface.
Typically, the multilayer-film coating is formed such that the layer pairs have a period length. The distribution of Γ can be continuous over a first portion of the surface in which angle of incidence of light incident to the surface is within a respective range and the period length is constant. In a second portion of the surface outside the first portion, Γ can be constant while the period length is increased. Alternatively, the distribution of Γ can be continuous over the surface, wherein the period length changes continuously over the surface.
According to yet another aspect of the invention, X-ray lithography tools are provided that comprise an X-ray light source, and illumination-optical system, and a projection-optical system. The X-ray light source is situated and configured to produce an X-ray illumination beam. The illumination-optical system is situated downstream of the X-ray light source and is configured to guide the illumination beam to a reticle, so as to form a patterned beam of X-ray light reflected from the reticle. The projection-optical system is situated downstream of the reticle and is configured to guide the patterned beam from the reticle to a sensitive substrate. At least one of the illumination-optical system, the reticle, and the projection-optical system comprises a multilayer-film mirror. The multilayer-film mirror comprises a multilayer film on a surface of a mirror substrate. The multilayer film is configured so as to render the surface reflective to one or more selected wavelengths of incident X-ray light. The multilayer film is formed of alternating superposed layers of a first and a second material arranged as multiple layer pairs superposed on the surface, the first material has a relatively large difference between its refractive index for soft-X-ray light and its refractive index in a vacuum. The second material has a relatively small difference between its refractive index for soft-X-ray light and its refractive index in a vacuum. Each layer of the first material in the multilayer film has a respective thickness, and, in at least one of the layer pairs, the ratio (Γ) of the thickness of the respective layer of the first material to a thickness of the layer pair has a variable distribution over at least a portion of the surface.
The foregoing and additional features and advantages of the invention will be apparent from the following detailed description, which proceeds with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 (A) is an elevational section schematically showing overall structure of a multilayer-film mirror according to a first representative embodiment, and FIG. 1 (B) is an elevational section schematically showing an exemplary layer pair of the mirror of FIG. 1 (A).
FIG. 2 is a schematic diagram of the overall structure of an embodiment of an X-ray lithography tool including a multilayer-film mirror such as that shown in FIG. 1 (A).
FIG. 3 is an elevational section schematically depicting a single layer pair in a multilayer-film mirror according to a second representative embodiment.
FIG. 4 (A) is an elevational section schematically showing overall structure of a multilayer-film mirror according to a third representative embodiment, and FIG. 4 (B) is an elevational section schematically showing an exemplary layer pair of the mirror of FIG. 4 (A).
FIG. 5 is an elevational section schematically depicting a single layer pair in a multilayer-film mirror according to a fourth representative embodiment.
FIG. 6 is a graph showing a theoretical relationship of reflectivity to angle of incidence in a multilayer-film mirror having a period length of 69 Å, a lamina count of 50 layer pairs, and an incident-light wavelength of 13.36 nm.
FIG. 7 is a graph showing the relationship of the period length and of total thickness of the multilayer film (period length×number of layer pairs) at which reflectivity is highest for an incident λ=13.36 nm versus the angle of incidence.
FIG. 8 shows curves exhibiting the relationship between incident wavelength and reflectivity of a multilayer-film mirror.
FIG. 9 is a series of plots of reflectivity versus angle of incidence at selected values of Γ.
DETAILED DESCRIPTION
Whenever the period length of a multilayer-flim-coated minor is changed in accordance with Bragg's equation, described above, the wavelength at which the reflectivity of the mirror is highest also changes. On the other hand, due to differences in the refractive indices of materials constituting the multilayer coating, the wavelength at which the mirror exhibits maximal reflectivity changes with corresponding changes in Γ, even while keeping the period length constant.
An exemplary relationship between incident wavelength and reflectivity is depicted in FIG. 8 . This graph shows the reflectivity, of light incident at 0° angle of incidence, of a Mo/Si multilayer coating having a period length of 69 Å. The abscissa is wavelength of incident light, and the ordinate is reflectivity. The various curves depict respective results observed as Γ is changed from 0.30 to 0.50 in increments of 0.05. As can be seen in FIG. 8, the wavelength of maximal reflectivity changes as Γ is changed, while keeping the period length constant. In other words, whenever Γ=0.50, a peak reflectivity of approximately 72% is observed at λ≈13.4 nm. Whenever Γ=0.30, a peak reflectivity of approximately 72% is observed at λ≈13.6 nm. Consequently, by changing F while keeping the period length of the multilayer film constant, the peak-reflectivity wavelength of the multilayer-film surface changed relative to a fixed angle of incidence, thus giving the same result as changing the period length of the multilayer film. Meanwhile, as was seen in FIG. 7, whenever the incident wavelength (λ) is fixed, the angle of incidence at which reflectivity is maximal changes with corresponding changes in the period length of the multilayer film. Consequently, if Γ is changed while keeping the period length constant, the angle of incidence, at which reflectivity is maximal, changes relative to a fixed incident wavelength. By exploiting these results, even if the period length of the multilayer film is kept constant relative to a fixed incident wavelength, Γ can be selected so that the angles of incidence at various points on the mirror surface are respective angles at which reflectivity is maximal.
FIG. 9 is a graph of reflectivity versus angle of incidence while changing Γ. The abscissa is angle of incidence and the ordinate is reflectivity. The graph is of data obtained when light of λ=13.36 nm was incident on a 50 layer-pair Mo/Si multilayer film having a period length of 69 Å. The various curves depict respective results of changing Γ.
It can be seen from FIG. 9 that the angle of incidence exhibiting maximal reflectivity changes according to Γ. In other words, the angle of incidence exhibiting maximal reflectivity is approximately 4° whenever Γ is 0.5, and is approximately 10° whenever Γ is 0.3. Hence, the smaller the value of Γ, the greater the difference, at which reflectivity is maximal, of the angle of incidence from 0°. Consequently, high reflectivity at various angles of incidence is obtained by selecting Γ at each angle of incidence so as to provide maximal reflectivity.
For example, Γ=0.45 exhibits the highest reflectivity at angles of incidence from 0° to 5°, while Γ=0.4 exhibits the highest reflectivity at angles of incidence from 5° to 8°, and Γ=0.35 exhibits the highest reflectivity at angles of incidence from 8° to 10°. To obtain the highest peak reflectivity over the surface of the multilayer-film mirror, it is desired that Γ appropriately range from 0.3 to 0.5 over the surface.
In FIG. 9, Γ was changed in increments of 0.05. It is especially desirable that Γ be changed in a continuous (non-stepped) manner to provide greater optimization of the reflectivity of the reflective surface. In order to select optimal values of Γ, θ and Γ desirably are correlated with each other by tracing the respective high-reflectivity envelope of each of the curves in FIG. 9 . Thus, whenever the wavelength of the incident light is 13.6 nm and the period length is constant at 69 Å, reflectivity changes from approximately 72% to approximately 74% at angles of incidence ranging from 0° to 10°. This allows the maximum decrease in reflectivity to be limited to approximately 1%.
To change Γ while keeping the period length of the multilayer film constant, both the film-thickness distribution of the Mo layer and the film-thickness distribution of the Si layer are changed simultaneously. Thus, a desired thickness of the multilayer film is achieved while Γ is locally changed as required to provide a desired distribution over the surface so that maximal (or nearly maximal) reflectivity is obtained. This can be accomplished by controllably varying the distribution of sputtered atoms as sputtering is being performed. Controllably varying the distribution of sputtered atoms is achieved by changing one or more film-formation parameters such as the sputtering condition and/or the angle of inclination of the film-formation substrate (mirror) during sputtering. Alternatively, controllably changing Γ over the surface can be accomplished by using a film-formation-correction mask for controlling the concentration of sputtered atoms actually reaching specific regions on the surface of the mirror. In any event, a desired distribution of Γ over the mirror surface is achieved.
FIGS. 1 (A)- 1 (B) depict the structure of a multilayer-film mirror according to a first representative embodiment. FIG. 1 (A) is an elevational section showing overall structure, and FIG. 1 (B) is an elevational section showing an exemplary layer pair in the multilayer film. FIG. 2 is a schematic diagram of the overall structure of an X-ray lithography tool including the multilayer-film mirror of FIGS. 1 (A)- 1 (B) and/or any of various other embodiments of the multilayer-film mirror.
Turning first to FIG. 2, the lithography tool 1 is a projection-exposure apparatus that performs a step-and-scan lithographic exposures using light in the soft X-ray band, having a wavelength of λ≈13 nm (EUV light), as the illumination light used for making lithographic exposures. A laser light source 3 is situated at the extreme upstream end of the tool 1 . The laser light source 3 produces laser light having a wavelength in the range of infrared to visible. For example, the laser light source 3 can be a YAG or excimer laser employing semiconductor laser excitation. The laser light emitted from the laser light source 3 is focused and directed by a condensing optical system 5 to a laser-plasma light source 7 . The laser-plasma light source 7 is configured to generate EUV radiation having a wavelength of λ≈13 nm.
A nozzle (not shown) is disposed in the laser-plasma light source 7 , from which xenon gas is discharged. As the xenon gas is discharged from the nozzle in the laser-plasma light source 7 , the gas is irradiated by the high-intensity laser light from the laser light source 3 . The resulting intense irradiation of the xenon gas causes sufficient heating of the gas to generate a plasma. Subsequent return of Xe molecules to a low-energy state results in the emission of EUV light from the plasma. Since EUV light has low transmissivity in air, its propagation path must be enclosed in a vacuum environment produced in a vacuum chamber 9 . Also, since debris tends to be produced in the environment of the nozzle from which the xenon gas is discharged, the chamber 9 desirably is separate from other chambers of the apparatus 1 .
A paraboloid mirror 11 , provided with a surficial multilayer Mo/Si coating, is disposed immediately upstream of the laser-plasma light source 7 . EUV radiation emitted from the laser-plasma light source 7 enters the paraboloid mirror 11 , and only EUV radiation having a wavelength of λ≈13 nm is reflected from the paraboloid mirror 11 as a coherent light flux in a downstream direction (downward in the figure). The EUV flux then encounters a pass filter 13 that blocks transmission of visible wavelengths of light and transmits the EUV wavelength. The pass filter 13 can be made, for example, of 0.15 nm-thick beryllium (Be). Hence, only EUV radiation having a wavelength of λ≈13 nm is transmitted through the pass filter 13 . The area around the pass filter 13 is enclosed in a vacuum environment inside a chamber 15 .
An exposure chamber 33 is situated downstream of the pass filter 13 . The exposure chamber 33 contains an illumination-optical system 17 that comprises at least a condenser-type mirror and a fly-eye-type mirror. EUV radiation from the pass filter 13 is shaped by the illumination-optical system 17 into a circular flux that is directed to the left in the figure toward an X-ray-reflective mirror 19 . The mirror 19 has a circular, concave reflective surface 19 a , and is held in a vertical orientation (in the figure) by holding members (not shown). The mirror 19 comprises a substrate made, e.g., of quartz or low-thermal-expansion material such as Zerodur (Schott). The reflective surface 19 a is shaped with extremely high accuracy and coated with a Mo/Si multilayer film that is highly reflective to 13 nm-wavelength X-rays. Whenever X-rays having wavelengths of 10 to 15 nm are used, the multilayer film on the surface 19 a can include a material such as ruthenium (Ru) or rhodium (Rh). Other candidate materials are silicon, beryllium (Be), and carbon tetraboride (B 4 C).
A bending mirror 21 is disposed at an angle relative to the mirror 19 to the right of the mirror 19 in the figure. A reflective reticle or mask 23 , that defines a pattern to be transferred lithographically to a sensitive substrate 29 , is situated “above” the bending mirror 21 . Note that the mask 23 is oriented horizontally with the reflective surface directed downward to avoid deposition of any debris on the surface of the mask 23 . X-rays emitted from the illumination-optical system 17 are reflected and focused by the X-ray reflective mirror 19 , and reach the reflective surface of the mask 23 via the bending mirror 21 .
The mask 23 has an X-ray-reflective surface configured as a multilayer film. Pattern elements, corresponding to pattern elements to be transferred to the sensitive substrate (“wafer”) 29 , are defined on or in the X-ray-reflective surface. The reflective mask 23 is mounted on a mask stage 25 that is movable in at least the Y-direction in the figure. Hence, X-rays reflected by the bending mirror 21 are incident at a desired location on the X-ray-reflective surface of the mask 23 .
A projection-optical system 27 and the wafer 29 are disposed downstream of the reflective mask 23 . The projection-optical system 27 comprises several X-ray-reflective mirrors. An X-ray beam from the reflective mask 23 , carrying an aerial image of the illuminated portion of the mask 23 , is “reduced” (demagnified) by a desired factor (e.g., ¼) by the projection-optical system and focused on the surface of the wafer 29 , thereby forming an image of the illuminated portion of the pattern on the wafer 29 . The wafer 29 is mounted by suction or other appropriate mounting force to a wafer stage 31 that is movable in the X-direction, Y-direction, and Z-direction.
A pre-exhaust chamber 37 (load-lock chamber) is connected to the exposure chamber 33 by a gate valve 35 . A vacuum pump 39 is connected to the pre-exhaust chamber 37 and serves to form a vacuum environment inside the pre-exhaust chamber 37 .
During a lithographic exposure performed using the apparatus shown in FIG. 2, EUV light is directed by the illumination-optical system 17 onto a selected region of the reflective surface of the mask 23 . As exposure progresses, the mask 23 and wafer 29 are scanned synchronously (by their respective stages 25 , 31 ) relative to the projection-optical system 27 at a specified velocity ratio determined by the demagnification ratio of the projection-optical system. Normally, because not all the pattern defined by the reticle can be transferred in one “shot,” successive portions of the pattern, as defined on the mask 23 , are transferred to corresponding shot fields on the wafer 29 in a step-and-scan manner. By way of example, a 25 mm×25 mm square chip can be exposed on the wafer 29 with a 0.07 μm line spacing IC pattern at the resist on the wafer 29 .
Turning now to FIGS. 1 (A)- 1 (B), the depicted mirror 50 can be used, for example, as the X-ray-reflective mirror 19 and/or the X-ray-reflective mirror 11 in the lithography tool 1 shown in FIG. 2 . The multilayer-film mirror 50 comprises a substrate 55 defining a concave surface on which is formed a multilayer film comprising 50 layer-pairs of Mo and Si having a 69 Å period length. Each period comprises one respective layer of Mo 56 and one respective layer of Si 57 comprising a respective “layer pair.” The angles of incidence of light impinging on the multilayer-film mirror 50 are 0° to 5° in the central region 51 in the figure, 5° to 8° in the intermediate regions 52 , and 8° to 10° in the outer regions 53 .
In one layer pair of this multilayer film, the respective thicknesses of the Mo layer 56 and the Si layer 57 are established so that Γ=0.45 in the region 51 , Γ=0.40 in the region 52 , and Γ=0.35 in the region 53 . Thus, in the depicted layer pair, Γ exhibits a “stepped” distribution over the reflective surface of the mirror. The values for Γ are obtained from FIG. 9, discussed above. This multilayer film is produced by ion-beam sputtering, using individual sputtered-atom correction plates for Mo and for Si when forming each respective layer. By configuring the multilayer film in this manner, decreases in reflectivity of the multilayer-film surface can be limited to about 1% for angles of incidence in the range from 0° to 10°.
FIG. 3 is an elevational section of a single layer pair in a multilayer-film mirror according to a second representative embodiment. The multilayer film in this embodiment has a structure in which the angles of incidence of light impinging on the mirror are distributed continuously from 0° to 10° from the center of the mirror toward the perimeter of the mirror. The respective thicknesses of the Mo layer 56 and the Si layer 57 in the depicted layer pair are established such that Γ is distributed continuously from 0.45 to 0.35 from the center of the mirror toward the perimeter of the mirror. Γ at each point on the substrate is selected so that reflectivity is maximized at the angle of incidence at that point. This multilayer film is produced by ion-beam sputtering, using individual sputtered-atom correction plates for Mo and for Si when forming each respective layer. By forming the multilayer film in this manner, decreases in reflectivity are limited to about 1% for angles of incidence ranging from 0° to 10°.
A third representative embodiment of a multilayer-film mirror 80 is shown in FIGS. 4 (A)- 4 (B), wherein FIG. 4 (A) is an elevational section schematically showing the overall structure, and FIG. 4 (B) is an elevational section schematically depicting an exemplary layer pair of the multilayer film. The multilayer-film mirror 80 has a structure similar to the multilayer-film mirror in FIGS. 1 (A)- 1 (B), wherein Mo layers 86 and Si layers 87 are alternately laminated on the curved surface of a substrate 85 . The angles of incidence of light impinging on this multilayer-film mirror 80 vary from 0° to 20° from the center of the substrate 85 to the perimeter of the substrate, respectively. I.e., the angles of incidence in the region 81 range from 0° to 10°, and the angles of incidence in the region 82 are 10° and greater.
In a single layer pair of this multilayer film, the respective thicknesses of the Mo layer 86 and the Si layer 87 are established such that r varies continuously from 0.45 to 0.35 from the center toward the edge of the region 81 in which the angles of incidence range from 0° to 10°, as in the embodiment of FIG. 3 . If Γ were to continue to diminish in the region 82 (from the edge contacting the region 81 to the edge of the mirror) in which the angle of incidence is 10° and greater, then the reflectivity would decrease as Γ drops below 0.35. To prevent such a decrease in reflectivity, a conventional compensation scheme (in which the thickness of the multilayer film is changed) is utilized in the region 82 . In other words, while maintaining Γ=0.35 in the region 82 , the period length is increased.
Thus, according to this embodiment, and with respect to mirrors in which a certain area has a broad range of angles of incidence that cannot be compensated for only by varying the distribution of Γ, a conventional scheme of changing the thickness of the multilayer film (i.e., changing the period length) can be applied locally. Thus, the magnitude of change in distribution of film thickness is smaller than when variations of the film-thickness distribution were performed in the conventional manner over the entire surface of the mirror. As a result, deterioration of the optical performance of the mirror is reduced compared to conventional methods.
In this embodiment the multilayer film was produced by ion-beam sputtering using individual sputter-correction plates for Mo and for Si when forming each respective layer. Alternatively, the distribution of Γ and the distribution of the multilayer-film thickness for a given region could be achieved using a single sputter-correction plate.
A fourth representative embodiment of a multilayer-film mirror 90 is shown in FIG. 5, providing an elevational section of an exemplary layer pair of the mirror. The multilayer-film mirror 90 has a structure similar to the multilayer-film mirror in FIGS. 1 (A)- 1 (B), wherein Mo layers 96 and Si layers 97 are alternately laminated onto the surface of a substrate 95 . In this embodiment, while continuously changing Γ from the center of the mirror toward the perimeter in a single layer pair, the period length also is changed continuously. In this case, the reflectivity is slightly lower than in situations in which corrections of the distribution of film thickness are performed by changing only the period length over the entire surface. However, in this embodiment, deterioration of optical performance of the mirror can be suppressed well for many uses. This embodiment is more desirable, from a practical standpoint, than the embodiment of FIGS. 4 (A)-(B).
Selecting maximal reflectivity by changing Γ, while maintaining constancy of the period length, as described above, is especially suitable for angles of incidence ranging from 0° to 10°. At angles of incidence greater than 10°, the multilayer film can be formed with Γ being relatively high (e.g., 0.4 to 0.45 at angles of incidence near 0°). The coating can be formed with Γ being lower (e.g., 0.3 to 0.35) at locations more off-axis by changing the period length.
As is clear from the foregoing, multilayer-film mirrors are provided that exhibit high reflectivity without having to change the period length of the multilayer film. Also, X-ray exposure apparatus are provide that include such multilayer-film mirrors, in which apparatus the multilayer-film mirrors exhibit high reflectivity without significant deterioration of optical performance.
Whereas the invention has been described in connection with multiple representative embodiments, the invention is not limited to those embodiments. On the contrary, the invention is intended to encompass all modifications, alternatives, and equivalents as may be included within the spirit and scope of the invention, as defined by the appended claims. | Multilayer-film mirrors are disclosed that exhibit high reflectivity to incident X-radiation independently of the angle of incidence and without significantly compromising optical performance. Also disclosed are X-ray optical systems and microlithography apparatus comprising such mirrors. In an embodiment a multilayer-film mirror is formed by alternately laminating Mo layers (a material in which the difference between its refractive index in the weak X-ray band and its refractive index in a vacuum is great) and Si layers (a material in which said difference is small) on a substrate. The ratio (Γ) of the thickness of the Mo layer to the total of the thickness of the Mo layer and the thickness of the Si layer has a distribution based on the distribution of angles of incidence of X-radiation on the mirror surface. By providing Γ with a distribution that corresponds with the distribution of the angles of incidence in the mirror surface, maximum reflectivity can be obtained at the angles of incidence at various points within the mirror surface. Because there is no need to change the period length in this case, there is no deterioration in the optical performance of the mirror. | 1 |
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