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BACKGROUND OF THE INVENTION
[0001] 1) Field of the Invention
[0002] The present invention relates to a synthetic resin laminate having both polarization characteristic and photochromism characteristic, and specifically to a synthetic resin laminate having good appearance and excellent optical characteristics which is used for glare-reducing materials such as goggle and sun glass for sport use and can be readily produced and processed.
[0003] 2) Prior Art
[0004] Goggles and sun glasses for sport use which have polarization characteristic exhibit excellent cutting characteristic against a reflected light. Thus, their usefulness in outdoor activities such as marine sport, skiing and fishing has come to be noticed widely. Recently, their demand has suddenly expanded. Particularly, when a polycarbonate resin is used for their material, the tendency is remarkable since it exhibits excellent impact resistance.
[0005] On the other hand, with rapid development of excellent photochromic pigment, the characteristic of photochromic sun glasses to change transmittance depending upon surrounding brightness also has remarkably been improved, so that they also have been rapidly enhancing popularity.
[0006] Ideas concerning a synthetic resin glare-reducing material having both a function to change transmittance depending on surrounding brightness and a function to block preferentially a reflected light have been suggested. However, in the present situation, they have not been put into practice yet, because even if a concrete constitution of a glare-reducing material with required properties was suggested, a concrete process for production thereof was practically poor or properties of a product thus obtained were insufficient in the present production process.
[0007] For example, in the production of a polycarbonate lens described in Japanese Patent Publication No.7-94154, when a process comprising adding a photochromic pigment in the production of a polycarbonate sheet to be used is applied, a lens thus obtained is insufficient in both response speed and contrast. Also in resins other than a polycarbonate, a sheet with strength usable as a glare-reducing material usually causes problems that degradation of a photochromic pigment occurs during kneading; the kneading is troublesome and contrast or response speed of a product thus obtained is small.
[0008] In a process comprising coating a surface layer of a polarizing lens to be obtained in the process described in Japanese Patent Publication No.7-94154 with a photochromic pigment-containing resin, it is difficult to form a lens with good contrast since the thickness of an applicable coating layer is limited.
SUMMARY OF THE INVENTION
[0009] The present invention is to provide a synthetic resin laminate for a glare-reducing material having both polarization characteristic and photochromism characteristic which can be readily processed.
[0010] As a result of extensive trials and studies for various methods, the inventors have found that a laminate interposed a resin layer having photochromism characteristic and a resin layer having polarization characteristic between two transparent synthetic resins exhibits not only excellent both photochromism characteristic and polarization characteristic, but also processing into curved surfaces and injection molding can be readily performed and the laminate can be produced in a very simple process, and have accomplished the present invention.
[0011] That is, the present invention provides a synthetic resin laminate having both phtochromism characteristic and polarization characteristic consisting essentially of two transparent synthetic resin layers, a resin layer having phtochromism characteristic and a resin layer having polarization characteristic interposed between said two transparent synthetic resin layers and an adhesive layer to adhere said resin layer having polarization characteristic to said one transparent synthetic resin layer, wherein said one transparent synthetic resin layer to contact said resin layer having phtochromism characteristic has a thickness of 50 μm or above and a retardation value of 150 nm or below, or 3000 nm or above.
[0012] It is preferable that said one transparent synthetic resin to contact said adhesive layer has a thickness of 100 μm or above.
[0013] It is preferable that said transparent synthetic resin is a polycarbonate resin. Also resins excellent in impact resistance, transparency and strength other than a polycarbonate resin can be used.
[0014] Further, it is preferable that said resin layer having photochromism characteristic is an urethane resin layer containing a photochromic pigment(s).
[0015] It is preferable that said resin layer having polarization characteristic is a polarizing film.
BRIEF DESCRIPTION OF THE DRAWING
[0016] [0016]FIG. 1 is a cross sectional view of the synthetic resin laminate in the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0017] The present invention will be described in detail using FIG. 1.
[0018] In FIG. 1, (A) shows a transparent synthetic resin layer (hereinafter, “(A)”); (B) shows a resin layer having photochromism characteristic (hereinafter, “(B)”); (C) shows a resin layer having polarization characteristic (hereinafter, “(C)”); (D) shows an adhesive layer (hereinafter, “(D)”) and (E) shows a transparent synthetic resin layer (hereinafter, “(E)”).
[0019] When the synthetic resin laminate of the present invention is used as a glare-reducing material such as a sun glass and a sporting goggle, the side of (A) (hereinafter, “(A) side”) is used as outside and the side of (E) (hereinafter, “(E) side”) is used as inside. For example, a user of a sun glass applied the synthetic resin laminate of the present invention sees objects from (E) side of the sun glass lens of inside through (A) side of the outside.
[0020] When the synthetic resin laminate is processed into curved surfaces, it is processed so as to form a concave shape in (A) side and a convex shape in (E) side. Further, when other resin is adhered to the synthetic resin laminate by injection molding, etc., notwithstanding a flat sheet or an article processed into curved surfaces, the other resin with low UV absorption and transparency may be adhered to (A) side or (E) side of the laminate. According to the said other resin added to UV absorption or pigment, it is preferabel that the said other resin is adhered to (A) side.
[0021] When the components, concentration and thickness of (A), (B), (C), (D) and (E) are combined as described later, the synthetic resin laminate exhibits excellent optical characteristics and it becomes possible to perform its processing into curved surfaces and injection molding.
[0022] Each layer in the synthetic resin laminate is described in detail below.
[0023] It is preferable that (A) has a thickness of 50 μm or above and a retardation value (hereinafter, “Re”) of 150 nm or below, or 3000 nm or above and substantially, (A) is a sheet to transmit a light with a wave length of 350 nm or above.
[0024] In the present invention, Re (nm) of the synthetic resin layer is defined in the following formula.
Retardation value ( Re )( nm )=Δ n×d
[0025] wherein Δn is a birefringence of the synthetic resin layer and d is a thickness (nm) of the synthetic resin layer.
[0026] When the synthetic resin laminate is used as a glare-reducing material outside the above-mentioned range of Re, it is not preferable since colored interference figure is generated.
[0027] When a polycarbonate resin is used as (A), it is required that it has a thickness of 50 to 200 μm and Re of 150 nm or below or a thickness of 300 μm to 1 mm and Re of 3000 nm or above. Outside the above-mentioned range, the following some problems occur.
[0028] (1) When the synthetic resin laminate is processed into curved surfaces, interference figure is observed.
[0029] (2) The synthetic resin laminate does not possess satisfactory strength.
[0030] (3) A processed article with good appearance cannot be obtained.
[0031] (4) Polarization characteristic is deteriorated in an injection molding.
[0032] (5) It is not practical since it is difficult to obtain a raw material.
[0033] The polycarbonate resin sheet having the above-mentioned range of Re in the present invention can be produced, for example, by the following process.
[0034] That is, the sheet having Re of 150 nm or below can be produced by a casting process or a non-stretching extrusion process. The sheet having Re of 3000 nm or above can be produced by changing a polycarbonate resin to a sheet by an extrusion process and then stretching substantially the sheet in one direction while heating to a somewhat higher temperature (e.g., about 140 to about 180° C.) than glass transition temperature. In such case, stretching magnification exerts an influence on Re.
[0035] It is preferable that (B) is an urethane resin layer containing a photochromic pigment(s) and (B) has a thickness of 50 to 250 μm. When the thickness is below 50 μm, color development is insufficient under irradiation of an ultraviolet light and contrast becomes low. When the thickness is above 250 μm, contrast is sufficient, but economy becomes bad since a large amount of high price photochromic pigment is used.
[0036] The photochromic pigment is not limited on the condition that it has compatibility with the urethane resin layer. Spiropyrane compounds, spiroxazine compounds and naphthopyran compounds are preferable.
[0037] Examples of the spiropyran compound include 1′,3′,3′-trimethylspiro(2H-1-benzopyran-2,2′-indoline), 1′,3′,3′-trimethylspiro-8-nitro(2H-1-benzopyran-2,2′-indoline), 1′,3′,3′-trimethyl-6-hydroxyspiro(2H-1-benzopyran-2,2′-indoline), 1′,3′,3′-trimethylspiro-8-methoxy(2H-1-benzopyran-2,2′-indoline), 5′-chloro-1′,3′,3′-trimethyl-6-nitrospiro(2H-1-benzopyran-2,2′-indoline), 6,8-dibromo-1′,3′,3′-trimethylspiro(2H-1-benzopyran-2,2′-indoline), 8-ethoxy-1′,3′,3′,4′,7′-pentamethylspiro(2H-1-benzopyran-2,2′-indoline), 5′-chloro-1′,3′,3′-trimethylspiro-6,8-dinitro(2H-1-benzopyran-2,2′-indoline), 3,3,1-diphenyl-3H-naphtho(2,1-b) pyran, 1,3,3-triphenylspiro[indoline-2,3′-(3H) -naphtho(2,1-b)pyran], 1-(2,3,4,5,6-pentamethylbenzyl)-3,3-dimethylspiro[indoline-2,3′-(3H)-naphtho(2,1-b)pyran], 1-(2-methoxy-5-nitrobenzyl)-3,3-dimethylspiro[indoline-2,3′-naphtho(2,1-b)pyran], 1-(2-nitrobenzyl)-3,3-dimethylspiro[indoline-2,3′-naphtho (2,1-b)pyran], 1-(2-naphthylmethyl)-3,3-dimethylspiro [indoline-2,3′-naphtho (2,1-b)pyran] and 1,3,3-trimethyl-6′-nitro-spiro[2H-1-benzopyran-2,2′-[2H]-indole].
[0038] Examples of the spiroxazine compound include 1,3,3-trimethylspiro [indolino-2,3′-[3H] naphth [2,1-b] [1,4] oxazine], 5-methoxy-1,3,3-trimethylspiro [indolino-2,3′-[3H] naphth [2,1-b] [1,4] oxazine], 5-chloro-1,3,3-trimethylspiro [indolino-2,3′-[3H] naphth [2,1-b] [1,4] oxazine], 4,7-diethoxy-1,3,3-trimethylspiro [indolino-2,3′-[3H] naphth [2,1-b] [1,4] oxazine], 5-chloro-1-butyl-3,3-dimethylspiro [indolino-2,3′-[3H] naphth [2,1-b] [1,4] oxazine], 1,3,3,5-tetramethyl-9′-ethoxyspiro [indolino-2,3′-[3H] naphth [2,1-b] [1,4] oxazine], 1-benzyl-3,3-dimethylspiro [indoline-2,3′-[3H] naphth [2,1-b] [1,4] oxazine], 1-(4-methoxybenzyl)-3,3-dimethylspiro [indoline-2,3′-[3H] naphth [2,1-b] [1,4] oxazine], 1-(2-methylbenzyl)-3,3-dimethylspiro [indoline-2,3′-[3H] naphth [2,1-b] [1,4] oxazine], 1-(3,5-dimethylbenzyl)-3,3-dimethylspiro [indoline-2,3′-[3H] naphth [2,1-b] [1,4] oxazine], 1-(4-chlorobenzyl)-3,3-dimethylspiro [indoline-2,3′-[3H] naphth [2,1-b] [1,4] oxazine], 1-(4-bromobenzyl)-3,3-dimethylspiro [indoline-2,3′-[3H] naphth [2,1-b] [1,4] oxazine], 1-(2-fluorobenzyl)-3,3-dimethylspiro [indoline-2,3′-[3H] naphth[2,1-b] [1,4] oxazine], 1,3,5,6-tetramethyl-3-ethylspiro [indoline-2,3′-[3H] pyrido [3,2-f] [1,4]-benzoxazine], 1,3,3,5,6-pentamethylspiro [indoline-2,3′-[3H] pyrido [3,2-f] [1,4]-benzoxazine], 6′-(2,3-dihydro-1H-indole-1-yl)-1,3-dihydro-3,3-dimethyl-1-propyl-spiro [2H-indole-2,3′-[3H] naphth [2,1-b] [1,4] oxazine], 6′-(2,3-dihydro-1H-indole -1-yl)-1,3-dihydro-3,3-dimethyl-1-(2-methylpropyl)-spiro [2H-indole-2,3′-[3H]-naphth [2,1-b] [1,4] oxazine], 1,3,3-trimethyl-1-6′-(2,3-dihydro-1H-indole-1-yl)-spiro [2H-indole-2,3′-[3H]-naphth [2,1-b] [1,4] oxazine], 1,3,3-trimethyl-6′-(1-piperidinyl)-spiro [2H-indole-2,3′-[3H]-naphth [2,1-b] [1,4] oxazine], 1,3,3-trimethyl-6′-(1-piperidinyl)-spiro[2H-indole-2,3′-[3H]-naphth[2,1-b] [1,4] oxazine], 1,3,3-trimethyl-6′-(1-piperidinyl)-6-(trifluoromethyl)-spiro [2H-indole-2,3′-[3H]-naphth [2,1-b] [1,4] oxazine] and 1,3,3,5,6-pentamethyl-spiro [2H-indole-2,3′-[3H] naphth [2,1-b] [1,4] oxazine].
[0039] Examples of the naphthopyran compound include 3,3-diphenyl-3H-naphtho [2,1-b] pyran, 2,2-diphenyl-2H-naphtho [1,2-b] pyran, 3-(2-fluorophenyl)-3-(4-methoxyphenyl)-3H-naphtho [2,1-b] pyran, 3-(2-methyl-4-methoxyphenyl)-3-(4-ethoxyphenyl)-3H-naphtho [2,1-b] pyran, 3-(2-furil)-3-(2-fluorophenyl)-3H-naphtho [2,1-b] pyran, 3-(2-thienyl)-3-(2-fluoro-4-methoxyphenyl)-3H-naphtho [2,1-b] pyran, 3-{2-(1-methylpyrrolidinyl)}-3-(2-methyl-4-methoxyphenyl)-3H-naphtho [2,1-b] pyran, Spiro [bicyclo [3.3.1] nonane-9,3′-3H-naphtho [2,1-b] pyran], Spiro [bicyclo [3.3.1] nonane-9-2′-3H-naphtho [2,1-b] pyran], 4-[4-[6-(4-morpholynyl)-3-phenyl-3H-naphtho [2,1-b] pyran-3-yl] phenyl]-morpholine, 4-[3-(4-methoxyphenyl)-3-phenyl-3H-naphtho [2,1-b] pyran-6-yl]-morpholine, 4-[3,3-bis(4-methoxyphenyl)-3H-naphtho [2,1-b] pyran-6-yl]-morpholine, 4-[3-phenyl-3-[4-(1-piperidinyl) phenyl]-3H-naphtho [2,1-b] pyran-6-yl]-morpholine and 2,2-diphenyl-2H-naphtho [2,1-b] pyran.
[0040] As processes for forming the urethane resin layer containing a photochromic pigment(s), the following various processes can be applied.
[0041] (1) A process comprising dissolving a polyurethane resin and a photochromic pigments(s) in a solvent, coating a solution thus obtained on (A) or (C), then evaporating the solvent and then adhering the urethane resin layer to (C) or (A) with heating.
[0042] (2) A process comprising heat melt adhering a polyurethane resin kneaded a photochromic pigments(s) to a transparent resin sheet so as to form a uniform thickness.
[0043] (3) A process comprising coating a resin solution dissolved a photochromic pigment(s) and a curing agent in a polyurethane prepolymer on (A) or (C), then evaporating a solvent (in case of containing a solvent), then adhering the urethane resin layer to (A) or (C) and then performing cure.
[0044] Although all of the above-mentioned processes can be applied in principle, it is preferable that a two-liquid type polyurethane containing a polyurethane prepolymer and a curing agent is used, considering productivity and necessary apparatus.
[0045] As the polyurethane prepolymer, a compound reacted isocyanate and polyol in a specific proportion is used. That is, the polyurethane prepolymer is a compound with an isocyanate group on both ends to be obtained from diisocyanate and polyol. It is preferable that the diisocyanate compound to be used for the polyurethane prepolymer is diphenylmethane-4,4′-diisocyanate (MDI). It is preferable that the polyol is polypropylene glycol (PPG) having a polymerization degree of 5 to 30.
[0046] The polyurethane prepolymer has a number average molecular weight of 500 to 5000, preferably 1500 to 4000 and more preferably 2000 to 3000.
[0047] The curing agent is not limited on the condition that it is a compound having two or above hydroxyl groups. Examples of the curing agent include polyurethane polyol, polyether polyol, polyester polyol, acrylic polyol, polybutadiene polyol and polycarbonate polyol. Among them, polyurethane polyol having a hydroxy group on its end to be obtained from specific isocyanate and specific polyol is preferable, and particularly it is preferable to use polyurethane polyol having a hydroxy group on at least both ends to be derived from diisocyanate and polyol. It is preferable that said diisocyanate is tolylene-diisocyanate (TDI) and said polyol is PPG having a polymerization degree of 5 to 30.
[0048] The curing agent has a number average molecular weight of 500 to 5000, preferably 1500 to 4000 and more preferably 2000 to 3000.
[0049] The ratio of isocyanate group (I) of the polyurethane prepolymer to hydroxyl group (H) of the curing agent of 0.9 to 20 and preferably 1 to 10 may be preferably applied as a standard.
[0050] Solvents such as ethyl acetate, tetrahydrofuran and toluene may be applied to the polyurethane prepolymer and the curing agent in order to adjust viscosity.
[0051] (C) may be basically any polarizing film. It is preferable that (C) has a comparatively high transmittance of 30% or above and a thickness of 10 to 100 μm. When the thickness is below 10 μm, strength becomes low and it is difficult to obtain intended polarization characteristic. When the thickness is above 100 μm, it is difficult to obtain uniformity of the thickness and ununiformity of color often occurs. An iodine type polarizing film is not so preferable and a dye type polarizing film is preferable, considering processing with heating such as injection molding.
[0052] Particularly, as described in Japanese Patent Kokai (Laid-open) No.63-311203, a film with high heat resistance produced by a process of production comprising performing particular treatment for a film with a metal ion(s) and boric acid to stabilize the film is preferable. Further, it is very preferable to use a polarizing film with UV cutting characteristic.
[0053] (D) may be any adhesive on the condition that conventional polycarbonate resin can be adhered to a polarizing film. A polyurethane resin to be used in the resin layer having photochromism characteristic of above-mentioned (B) is usually applied as the adhesive. Particularly, it is preferable to apply a two-liquid type polyurethane containing a polyurethane prepolymer and a curing agent, considering post processing. The range of thickness of (D) is preferably 5 to 100 μm and more preferably 5 to 50 μm. When the thickness is below 5 μm, it is difficult to obtain sufficient adhesive force. When the thickness is above 100 μm, the adhesive force is sufficient, but the long time is required to evaporate a solvent in the adhesive, so that productivity and economy becomes bad. It is possible to provide UV cutting potency for the laminate by adding a UV absorber to (D).
[0054] When the synthetic resin laminate is used in an injection molding, it is necessary that (E) has a thickness of 100 μm or above. When the thickness is below 100 μm, lines and crack are often generated. Further, it is necessary to select the thickness of (E) so as to make total thickness of the synthetic resin laminate 0.6 mm or above from the aspect of strength and quality except that afterwards its thickness is increased by a process such as injection molding.
[0055] Particularly, a preferable process for producing the synthetic resin laminate of the present invention is as follows.
[0056] That is, a resin solution containing a photochromic pigment(s), a polyurethane prepolymer and a curing agent is coated on a polarizing film and then standing at a temperature of 20 to 50° C. for about 5 to 60 minutes. Then, a transparent synthetic resin sheet (A) is adhered to the resin solution layer. An adhesive containing a solvent is coated on the side of the polarizing film of the laminate thus obtained and then standing for about 5 to 60 minutes at a temperature of 20 to 50° C. and the solvent is evaporated. Then, another transparent synthetic resin layer(E) is adhered to the adhesive. The laminate thus obtained is heat cured usually at a temperature of 60 to 140° C. over 2 hours to one week, whereby the synthetic resin laminate of the present invention is produced.
PREFERRED EMBODIMENTS OF THE INVENTION
[0057] The present invention will be described in more detail below, referring to examples which are not intended to limit the scope of the present invention.
[0058] Each properties was measured by the following methods.
[0059] [Transmittance]
[0060] The measurement was performed with a spectrophotometer, manufactured by Nihon Bunko k.k., in Japan. [Single Sheet Transmittance, Paralled Position Transmittance and Perpendicularly Crossing Position Transmittance]
[0061] Single sheet Transmittance, parallel position transmittance (H 0 : light transmittance where the same species of two polarizing films or two sheets to each other are overlapped so as to pose orientation direction toward the same direction to each other) and perpendicularly crossing position transmittance (H 90 : light transmittance where the same species of two polarizing films or two sheets to each other are overlapped so as to pose orientation direction toward a direction perpendicular to each other) are an average value made visible sensitivity amendment in a visible radiation of 400 to 700 nm.
[0062] [Polarization Degree]
[0063] Polarization degree was determined from the following formula
H ( % ) = H 0 - H 90 H 0 + H 90 × 100 ( % )
[0064] [Retardation Value (Re)]
[0065] The measurement was performed with a polarizing microscope, manufactured by Oak Seisakusho, in Japan, TEM-120AFT.
[0066] [Transmittance Under Irradiation of Ultraviolet Light]
[0067] A single wave length light of 360 nm was irradiated with a monochromatic light source and transmittance was measured after 5 minutes from the starting of the irradiation.
EXAMPLE 1
[0068] (1) Preparation of Photochromic Pigment-containing Resin Solution.
[0069] 15 g of a polyurethane prepolymer having a NCO group equivalent weight (equivalent weight: average molecular weight per one functional group) of 1500 prepared from diphenylmethane-4,4′-diisocyanate (MDI) and polypropylene glycol (PPG) having an average polymerization degree of 15, 3 g of a curing agent having a hydroxyl group equivalent weight of 1050 prepared from tolylenediisocyanate and polypropylene glycol having an average polymerization degree of 10, 0.25 g of a photochromic pigment {circle over (1)} [3,3-diphenyl-3H-naphtho (2,1-b) pyran], 0.08 g of a photochromic pigment {circle over (1)} [spiro (2H-indole-2,3′-(3H)-naphtho (2,1-b) (1,4) oxazine)-1,3-dihydro-1,3,3-trimethyl-6′-(1-piperidinyl)], 0.18 g of a hindered amine compound [bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate] and 12 g of tetrahydrofuran were uniformly mixed.
[0070] (2) Preparation of Polarizing Film
[0071] A polyvinyl alcohol film, manufactured by Kurare k.k., in Japan, trade name; Kurarevinylone #7500 was dyed at 35° C. for 6 minutes in an aqueous solution (dyeing solution) containing 0.37 g/L of Chlorantin fast red (C.I. (color index generic name): Direct Red 81), 0.28 g/L of Brilliant blue 6B (C.I.: Direct Blue 1), 0.28 g/L of Direct copper blue 2B (C.I.: Direct Blue 168), 0.93 g/L of Primuler blue 6 GL (C.I.: Direct Blue 202) and 0.28 g/L of Chrysophenine (C.I.: Direct Yellow 12) and then stretched 5 times in the dyeing solution to the direction of uniaxis.
[0072] Then, the above-mentioned film was immersed in an aqueous solution (treating solution) containing 0.30 g/L of nickel acetate tetrahydrate and 12.2 g of boric acid at a room temperature for 3 minutes in the state maintained stretching. Further, the film was taken out from the aqueous solution in the state maintained the tension and water washed and dried, and then subjected to heat treatment at 110° C. for 7 minutes.
[0073] The polarizing film thus obtained presented light grey and had a thickness of 30 μm and its optical characteristics were single sheet transmittance: 41.8% and polarization degree: 96.3%.
[0074] (3) Preparation of Resin Solution for Adhesive Layer
[0075] 15 g of above-mentioned polyurethane prepolymer, 3 g of above-mentioned curing agent and 27 g of ethyl acetate were uniformly mixed.
[0076] (4) Production of Laminate
[0077] The resin solution obtained by the process of above-mentioned (1) was coated with a doctor blade of coating thickness 300 μm, manufactured by Yoshimitsu Seiki k.k., in Japan on the polarizing film obtained in above-mentioned (2), and then standing for 10 minutes in the atmosphere of 45° C. Then, the surface coated with the resin liquid was adhered to a polycarbonate film of thickness 120 μm and Re 60 nm. The thickness of the laminate was 313 μm by measurement with a micrometer. It was found that the thickness of the resin layer having photochromism characteristic was 163 μm.
[0078] Then, an urethane adhesive was coated with a bar coater #24 on the side of the polarizing film in the laminate so as to form a thickness of 10 μm after evaporation of the solvent and a solvent was vaporized and then a polycarbonate sheet of thickness 300 μm was adhered thereto.
[0079] The laminate thus obtained was heat cured at 70° C. for 2 days. The total thickness of the laminate thus obtained was 620 μm.
[0080] When a light was not irradiated on the laminate, the transmittance was 41.9% and the polarization degree was 96.2%. Thus, the optical characteristics of the laminate were the same as those of the polarizing film. The color of the non-irradiated laminate was light grey.
[0081] On the other hand, when a sun light was irradiated on the laminate, the color of the laminate was changed to deep brown within 10 seconds. It was found that when the irradiation was stopped, the color reverted to original light grey in a short time of about 10 seconds.
[0082] The single sheet transmittance was 24.5% and the polarization degree was 96.4% during irradiation of an ultraviolet light. The visual observation result under a sun light was numerically confirmed. The appearance of the laminate was very good.
EXAMPLE 2
[0083] The laminate sheet obtained in Example 1 was cut into a size of 80 mm φ and then aspirated up to 50 mmHg for 1 minute simultaneously with starting of heating in the atmosphere of 147° C. and vacuum molded for 6 minutes to process into a lens of curvature radius 80 mm.
[0084] The appearance of the article obtained by processing into curved surfaces was very good and no interference figure thereof was observed. The optical characteristics of the processed article were the same as those prior to processing in both cases of light irradiation and non-irradiation.
EXAMPLE 3
[0085] In order to adhere the sheet subjected to processing into curved surfaces obtained in Example 2 to a molded article with an injection molder of clamping force 150 ton, it was in advance installed in a mold of a set temperature 110° C. with cavity of the curved form. An aromatic polycarbonate resin (trade name: IUPILON H-4000, manufactured by Mitsubish Gas Chemical Co., Inc.) put in a hot wind drier at 120° C. for 6 hours or above sufficient to satisfy the mold cavity in a molder cylinder of set temperature 260° C. was weighed. The molten polycarbonate resin was injection charged in the cavity of the closed molder installed the sheet subjected to processing into curved surfaces and then maintained for 30 seconds under a retention pressure of 700 kg/cm 2 and then the molded article was cool solidified in the mold for 120 seconds. Then, the mold was opened and the molded article was taken out from the mold.
[0086] The surface of molded article thus obtained was adhered to the sheet subjected to processing into curbed surfaces in advance installed. The molded article with good appearance was obtained. The molded article possesses both polarization characteristic and photochromism characteristic and its strain was small.
EXAMPLE 4
[0087] (1) Preparation of Photochromic Pigment-containing Resin Solution.
[0088] The preparation was performed in the same manner as in Example 1 except that the photochromic pigments were changed to 0.17 g of Reversacol Flame, manufactured by James Robinson Co.
[0089] (2) Preparation of Polarizing Film
[0090] The preparation was performed in the same manner as in Example 1.
[0091] (3) Production of Laminate
[0092] A laminate of both sides thickness 600 μm and total thickness about 1.4 mm was obtained in the same manner as in Example 1 by using two polycarbonate sheets of thickness 600 μm and Re 4000 nm.
[0093] The laminate presented deep orange under the irradiation of a sun light and light grey under the non-irradiation of a light. The transmittance was 42.1% and the polarization degree was 95.7%.
[0094] The laminate was cut into a shape of length 40 mm and width 200 mm and then subjected to processing into curved surfaces to form a spherical surface with curvature radius 85 mm under the conditions according to Example 2.
[0095] The color and brightness of the article subjected to processing into curved surfaces were the same as those prior to processing in both cases of irradiation and non-irradiation of a sun light.
[0096] Its appearance was very good without observing skewness and no interference figure was observed. Thus, it was judged that it was suitable to skiing goggle.
COMPARATIVE EXAMPLE 1
[0097] The laminate was produced in the same manner as in Example 1 except that Re of the polycarbonate film corresponding to (A) was changed from 60 nm to 1500 nm. The thickness of the laminate thus obtained was 622 μm. The laminate was subjected to processing into curved surfaces to make a lens. When a reflected light was seen through the lens, an interference figure was observed.
COMPARATIVE EXAMPLE 2
[0098] The laminate was produced in the same manner as in Example 1 except that the resin solution obtained in (1) was coated on the polarizing film obtained in (2) and then the surface coated with the resin solution was adhered to a polycarbonate sheet of thickness 300 μm and Re 1000 nm and then a urethane adhesive was coated on the side of the polarizing film in the laminate and adhered to a polycarbonate film of thickness 120 μm and Re 60 nm. The thickness of the laminate thus obtained was 614 μm.
[0099] A sun light was irradiated on the side of the polycarbonate film of thickness 120 μm and Re 60 nm in the laminate. The laminate was changed to somewhat brownish color, but so remarkable color development as in Example 1 was not observed. The transmittance under irradiation of an ultraviolet light from the same direction as that of a sun light was about 36%.
COMPARATIVE EXAMPLE 3
[0100] The laminate was produced in the same manner as in Example 1 except that the resin solution was prepared without adding the photochromic pigment {circle over (1)} and the photochromic pigment {circle over (1)}. The thickness of the laminate thus obtained was 618 μm. When the laminate was exposed to a sun light, no color development was observed and both transmittance and polarization degree in non-irradiation of an ultraviolet were the same as those in the case of non-irradiation of a light in Example 1. Glare reduction was not attained so much as in the laminate produced in Example 1 to develop color under irradiation of an ultraviolet light.
COMPARATIVE EXAMPLE 4
[0101] The photochromic pigment-containing resin solution was prepared in the same manner as in Example 1. The resin solution was coated on a polycarbonate sheet of thickness 300 μm, with a doctor blade of thickness 300 μm, manufactured by Yoshimitsu Seiki k.k., in Japan and then standing for 10 minutes in the atmosphere of 45° C. Then, the surface coated with the resin solution was adhered to a polycarbonate film of thickness 120 μm and Re 60 nm. The thickness of the laminate thus obtained was 578 μm and the thickness of the photochromic resin layer was 158 μm by measurement with a micrometer. Then, the laminate was heat cured for 2 days at 70° C. Total thickness of the laminate thus obtained was 575 μm.
[0102] The transmittance of the laminate in non-irradiation of an ultraviolet light was 83% and the transmittance under irradiation of an ultraviolet light was 64%. The laminate has no polarization characteristic and glare-reduction was not attained so much as the laminate of Example 1.
[0103] The synthetic resin laminate of the present invention, having both polarization characteristic and photochromism characteristic is suitably applicable to the use of glare-reducing materials such as sporting goggle and sun glass and a synthetic resin sun glass with magnification can be readily produced by the combination with an injection molding. | A synthetic resin laminate having both phtochromism characteristic and polarization characteristic consisting essentially of two transparent synthetic resin layers, a resin layer having phtochromism characteristic and a resin layer having polarization characteristic interposed between said two transparent synthetic resin layers and an adhesive layer to adhere said resin layer having polarization characteristic to said one transparent synthetic resin layer, wherein said one transparent synthetic resin layer to contact said resin layer having phtochromism characteristic has a thickness of 50 μm or above and a retardation value of 150 nm or below, or 3000 nm or above. | 8 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a method of making a perpendicular recording magnetic head pole tip with an etchable adhesion CMP stop layer and, more particularly, to the steps in making the perpendicular recording pole tip wherein such a layer adheres well to bottom and top layers, is commonly etchable with the bottom layer, adheres well to the pole tip during chemical mechanical polishing (CMP) to prevent delamination and indicates a stop point during the CMP for proper pole tip definition.
[0003] 2. Description of the Related Art
[0004] The heart of a computer is a magnetic disk drive which includes a rotating magnetic disk, a slider that has write and read heads, a suspension arm and an actuator arm. When the disk is not rotating the actuator arm locates the suspension arm so that the slider is parked on a ramp. When the disk rotates and the slider is positioned by the actuator arm above the disk, air is swirled by the rotating disk adjacent an air bearing surface (ABS) of the slider causing the slider to ride on an air bearing a slight distance from the surface of the rotating disk. When the slider rides on the air bearing the actuator arm positions the write and read heads over selected circular tracks on the rotating disk where field signals are written and read by the write and read heads. The write and read heads are connected to processing circuitry that operates according to a computer program to implement the writing and reading functions.
[0005] A write head is typically rated by its areal density which is a product of its linear bit density and its track width density. The linear bit density is the number of bits which can be written per linear inch along the track of the rotating magnetic disk and the track width density is the number of tracks that can be written per inch along a radius of the rotating magnetic disk. The linear bit density is quantified as bits per inch (BPI) and the track width density is quantified as tracks per inch (TPI). The linear bit density depends upon the length of the bit along the track and the track width density is dependent upon the width of the second pole tip at the ABS. Efforts over the years to increase the areal density have resulted in computer storage capacities increasing from kilobytes to megabytes to gigabytes.
[0006] The magnetic moment of each pole piece of a write head is parallel to the ABS and to the major planes of the layers of the write head. When the write current is applied to the coil of the write head the magnetic moment rotates toward or away from the ABS, depending upon whether the write signal is positive or negative. When the magnetic moment is rotated from the parallel position, magnetic flux fringing between the pole pieces writes a positive or a negative bit in the track of the rotating magnetic disk. As the write current frequency is increased, the linear bit density is also increased. An increase in the linear bit density is desirable in order to increase the aforementioned areal density which increase results in increased storage capacity.
[0007] There are two types of magnetic write heads. One type is a longitudinal recording write head and the other type is a perpendicular recording write head. In the longitudinal recording write head the flux induced into first and second pole pieces by a write coil fringes across a write gap layer, between the pole pieces, into the circular track of the rotating magnetic disk. This causes an orientation of the magnetization in the circular disk to be parallel to the plane of the disk which is referred to as longitudinal recording. The volume of the magnetization in the disk is referred to as a bit cell and the magnetizations in various bit cells are antiparallel so as to record information in digital form. The bit cell has a width representing track width, a length representing linear density and a depth which provides the volume necessary to provide sufficient magnetization to be read by a sensor of the read head. In longitudinal recording magnetic disks this depth is somewhat shallow. The length of the bit cell along the circular track of the disk is determined by the thickness of the write gap layer. The write gap layer is made as thin as practical so as to decrease the length of the bit cell along the track which, in turn, increases the linear bit density of the recording. The width of the second pole tip of the longitudinal write head is also made as narrow as possible so as to reduce the track width and thereby increase the track width density. Unfortunately, the reduction in the thickness of the write gap layer and the track width is limited because the bit cell is shallow and there must be sufficient bit cell volume in order to produce sufficient magnetization in the recorded disk to be read by the sensor of the read head.
[0008] In a perpendicular recording write head there is no write gap layer. The second pole piece has a pole tip with a width that defines the track width of the write head and a wider yoke portion which delivers the flux to the pole tip. At a recessed end of the pole tip the yoke flares laterally outwardly to its full width and thence to a back gap which is magnetically connected to a back gap of a first pole piece. The perpendicular write head records signals into a perpendicular recording magnetic disk. In the perpendicular recording magnetic disk a soft magnetic layer underlies a perpendicular recording layer which has a high coercivity H C . The thicker disk permits a larger bit cell so that the length and the width of the cell can be decreased and still provide sufficient magnetization to be read by the read head. This means that the width and the thickness or height of the pole tip at the ABS can be reduced to increase the aforementioned TPI and BPI. The magnetization of the bit cell in a perpendicular recording scheme is perpendicular to the plane of the disk as contrasted to parallel to the plane of the disk in the longitudinal recording scheme. The flux from the pole tip into the perpendicular recording magnetic disk is in a direction perpendicular to the plane of the disk, thence parallel to the plane of the disk in the aforementioned soft magnetic underlayer and thence again perpendicular to the plane of the disk into the first pole piece to complete the magnetic circuit. Accordingly, the width of the perpendicular recording pole tip can be less than the width of the second pole tip of the longitudinal write head and the height or thickness of the perpendicular recording pole tip can be less than the length of the longitudinal recorded bit cell so as to significantly increase the aforementioned areal density of the write head.
[0009] The perpendicular recording pole tip is typically constructed by frame plating in the same manner as the construction of the second pole piece in a longitudinal recording head. It is desirable that the pole tip be fully saturated during the write function. This allows an increase in the write signal frequency so as to increase the linear density of the recording. Unfortunately, when the length of the pole tip is short, it is difficult to fabricate a narrow width pole tip because of the loss of the process window of the pole tip in a region where the pole tip meets the flared portion of the second pole piece.
SUMMARY OF THE INVENTION
[0010] One approach to overcome this problem is to fabricate the perpendicular recording pole tip by a damascene process whereby a planar, homogenous dielectric layer is deposited with a carbon or diamond like carbon (DLC) hard mask thereon to serve as a chemical mechanical polishing (CMP) stop layer. The hard mask is patterned by photoresist and the dielectric is etched to form a beveled deep trench. Either deposition of a seed layer followed by plating or sputter deposition of an appropriate material with high moment can be used to fill the trench. Pole tip definition is achieved by CMP the structure back to the hard mask. A silicon adhesion layer on top and bottom of the hard mask has been required for adhesion of the hard mask to the dielectric and photoresist layers, thus increasing the number of processing steps. Silicon has excellent adhesion to DLC but does not adhere well to high moment material such as NiFe, CoNiFe and CoFe, which frequently results in delamination of the high moment material which forms the pole tip during CMP.
[0011] In order to overcome the aforementioned problems with the damascene process the present invention provides a non-silicon commonly etchable adhesion CMP stop layer (adhesion/stop layer) in the process of fabricating the second pole piece pole tip. The adhesion layer is tantalum (Ta). The improved adhesion/stop layer has several desirable attributes, namely: (1) improved adherence to a bottom pole tip forming layer which may be selected from the group consisting of Mo, W, Ta 2 O 3 , SiON X , SiO 2 and Si 3 N 4 , and to a top photoresist layer; (2) etchable by the same reactive ion etching (RIE) process that etches the forming layer; (3) adheres well to the iron alloys employed for the perpendicular recording second pole tip, such as NiFe, CoNiFe and CoFe, thereby preventing delamination of the pole tip during chemical mechanical polishing (CMP) to define the height of the pole tip; and (4) provides a stop indication during CMP so that the pole tip can be fabricated with a precise height.
[0012] A method of the invention comprises forming a second pole piece layer that is recessed from a head surface of the magnetic head assembly, forming a reactive ion etchable (RIEable) pole tip forming layer on the second pole piece layer, forming the adhesion/stop layer of Ta on the pole tip forming layer, forming a photoresist mask on the adhesion/stop layer with a first opening for patterning the adhesion/stop layer and the pole tip forming layer with a second opening, reactive ion etching (RIE) through the first opening to form the second opening, forming the second pole piece pole tip in the second opening with a top which is above a top of the adhesion/stop layer and chemically mechanically polishing (CMP) the top of the second pole piece pole tip until the CMP contacts the adhesion/stop layer. An aspect of the invention is that after forming the second pole piece layer and before forming the pole tip forming layer, alumina is formed on the second pole piece layer and in a field about the second pole piece layer and then CMP is implemented until a top of the second pole piece layer is exposed and a flat surface is formed, followed by forming the pole tip forming layer on the flat surface.
[0013] Other aspects of the invention will be appreciated upon reading the following description taken together with the accompanying drawings wherein the various figures are not to scale with respect to one another nor are they to scale with respect to the structure depicted therein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a plan view of an exemplary prior art magnetic disk drive;
[0015] FIG. 2 is an end view of a prior art slider with a magnetic head of the disk drive as seen in plane 2 - 2 of FIG. 1 ;
[0016] FIG. 3 is an elevation view of the prior art magnetic disk drive wherein multiple disks and magnetic heads are employed;
[0017] FIG. 4 is an isometric illustration of an exemplary prior art suspension system for supporting the slider and magnetic head;
[0018] FIG. 5 is an ABS view of the magnetic head taken along plane 5 - 5 of FIG. 2 ;
[0019] FIG. 6 is a longitudinal cross-sectional view of the slider taken along plane 6 - 6 of FIG. 2 showing the present perpendicular recording head in combination with a read head;
[0020] FIG. 7 is an ABS view of the slider taken along plane 7 - 7 of FIG. 6 ;
[0021] FIG. 8 is a view taken along plane 8 - 8 of FIG. 6 with all material above the coil layer and leads removed;
[0022] FIG. 9 is an isometric view of a second pole piece of FIG. 6 which includes a bottom pole piece and a top pole tip layer;
[0023] FIG. 10 is a top view of FIG. 9 ;
[0024] FIGS. 11A and 11B are a longitudinal view and an ABS view of the steps involved in fabricating the read head portion 72 of FIG. 6 ;
[0025] FIGS. 12A and 12B are the same as FIGS. 11A and 11B except the first pole piece has been planarized, the coils are fabricated, insulation is provided for the coils, a back gap has been constructed and an alumina layer has been deposited;
[0026] FIGS. 13A and 13B are the same as FIGS. 12A and 12B except the top of the partially completed head has been chemically mechanically polished (CMP) to provide a flat surface where an alumina isolation layer is formed;
[0027] FIGS. 14A and 14B are the same as FIGS. 13A and 13B except a second pole piece layer has been formed;
[0028] FIGS. 15A and 15B are the same as FIGS. 14A and 14B except an alumina layer has been deposited and CMP has been implemented to provide a flat surface;
[0029] FIGS. 16A and 16B are the same as FIGS. 15A and 15B except a hard mask has been formed;
[0030] FIGS. 17A and 17B are the same as FIGS. 16A and 16B except an adhesion/stop seed layer of Ta has been formed and a photoresist layer, which is being patterned, is formed on the Ta layer;
[0031] FIGS. 18A and 18B are the same as FIGS. 17A and 17B except reactive ion etching has been implemented into the hard mask and the adhesion/stop seed layer producing an opening for a second pole piece pole tip;
[0032] FIGS. 19A and 19B are the same as FIGS. 18A and 18B except a NiFe seed layer has been formed in the opening;
[0033] FIGS. 20A and 20B are the same as FIGS. 19A and 19B except the opening has been filled with ferromagnetic material;
[0034] FIGS. 21A and 21B are the same as FIGS. 20A and 20B except the magnetic head has been CMP until the CMP reaches the adhesion/stop seed layer;
[0035] FIGS. 22A and 22B are the same as FIGS. 21A and 21B except the hard mask has been removed by RIE;
[0036] FIG. 23 is an enlarged ABS illustration of the perpendicular recording pole tip in FIG. 22B ; and
[0037] FIG. 24 is an enlarged ABS illustration of another embodiment of the perpendicular recording second pole tip.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Magnetic Disk Drive
[0038] Referring now to the drawings wherein like reference numerals designate like or similar parts throughout the several views, FIGS. 1-3 illustrate a magnetic disk drive 30 . The drive 30 includes a spindle 32 that supports and rotates a magnetic disk 34 . The spindle 32 is rotated by a spindle motor 36 that is controlled by a motor controller 38 . A slider 42 has a combined read and write magnetic head 40 and is supported by a suspension 44 and actuator arm 46 that is rotatably positioned by an actuator 47 . A plurality of disks, sliders and suspensions may be employed in a large capacity direct access storage device (DASD) as shown in FIG. 3 . The suspension 44 and actuator arm 46 are moved by the actuator 47 to position the slider 42 so that the magnetic head 40 is in a transducing relationship with a surface of the magnetic disk 34 .
[0039] When the disk 34 is rotated by the spindle motor 36 the slider is supported on a thin (typically, 0.05 μm) cushion of air (air bearing) between the surface of the disk 34 and the air bearing surface (ABS) 48 . The magnetic head 40 may then be employed for writing information to multiple circular tracks on the surface of the disk 34 , as well as for reading information therefrom. Processing circuitry 50 exchanges signals, representing such information, with the head 40 , provides spindle motor drive signals for rotating the magnetic disk 34 , and provides control signals to the actuator for moving the slider to various tracks. In FIG. 4 the slider 42 is shown mounted to a suspension 44 . The components described hereinabove may be mounted on a frame 54 of a housing 55 , as shown in FIG. 3 .
[0040] FIG. 5 is an ABS view of the slider 42 and the magnetic head 40 . The slider has a center rail 56 that supports the magnetic head 40 , and side rails 58 and 60 . The rails 56 , 58 and 60 extend from a cross rail 62 . With respect to rotation of the magnetic disk 34 , the cross rail 62 is at a leading edge 64 of the slider and the magnetic head 40 is at a trailing edge 66 of the slider.
[0041] FIG. 6 is a side cross-sectional elevation view of a merged magnetic head assembly 40 , which includes a write head portion 70 and a read head portion 72 , the read head portion employing a read sensor 74 . FIG. 7 is an ABS view of FIG. 6 . The sensor 74 is sandwiched between nonmagnetic electrically nonconductive first and second read gap layers 76 and 78 , and the read gap layers are sandwiched between ferromagnetic first and second shield layers 80 and 82 . In response to external magnetic fields, the resistance of the sensor 74 changes. A sense current I S (not shown) conducted through the sensor causes these resistance changes to be manifested as potential changes. These potential changes are then processed as readback signals by the processing circuitry 50 shown in FIG. 3 .
[0042] As shown in FIGS. 6 and 7 , the write head portion 70 includes first and second pole pieces 100 and 102 which extend from the ABS to back gap portions 104 and 106 which are recessed in the head and which are magnetically connected to a back gap layer 108 . Located between the first and second pole pieces 100 and 102 is an insulation stack 110 which extends from the ABS to the back gap layer 108 and has embedded therein at least one write coil layer 112 . The insulation stack 110 may have a bottom insulation layer 114 which insulates the write coil from the first pole piece 100 and insulation layers 116 and 118 which insulate the write coil layer from the second pole piece 102 , respectively. An alumina layer 119 is located between the coil layer and the ABS.
[0043] Since the second shield layer 82 and the first pole piece layer 100 are a common layer this head is known as a merged head. In a piggyback head the second shield layer and the first pole piece layer are separate layers which are separated by a nonmagnetic layer. As shown in FIGS. 2 and 4 , first and second solder connections 120 and 121 connect leads (not shown) from the spin valve sensor 74 to leads 122 and 123 on the suspension 44 , and third and fourth solder connections 124 and 125 connect leads 126 and 127 from the coil 84 (see FIG. 8 ) to leads 128 and 129 on the suspension.
[0044] As shown in FIGS. 9 and 10 , the second pole piece 102 includes a bottom ferromagnetic layer 130 and a top ferromagnetic pole tip layer 132 . The layers 130 and 132 have flare points 134 and 136 where the layers first commence to extend laterally outwardly after the ABS. The pole tip layer 132 has a pole tip 138 and a yoke which is located between the pole tip 138 and the back gap 108 (see FIG. 6 ). The width of the top of the pole tip 138 is the track width (TW) of the recording head. The pole tip 138 is shown extended forward of the ABS in FIGS. 9 and 10 since this is its configuration when it is partially constructed on a wafer where rows and columns of magnetic head assemblies are fabricated. After completion of the magnetic head assemblies, which will be discussed hereinafter, the head assemblies are diced into rows of magnetic head assemblies and lapped to the ABS shown in FIG. 6 . Each row of magnetic head assemblies is then diced into individual head assemblies and mounted on the suspensions, as shown in FIG. 3 .
[0045] As shown in FIGS. 6 and 7 , an insulative pole tip forming layer (PT forming layer) 140 is located between the flare point 134 and the ABS. The PT forming layer 140 is not a write gap layer as employed in a longitudinal recording head and therefore does not determine the linear bit density along the track of the rotating magnetic disk. In contrast, the thickness or height of the pole tip 138 along with media and spacing requirements determine the linear bit density since the flux signal magnetizes the bit cells in the recording disk in a perpendicular direction with the flux from the second pole piece returning to the first pole piece 100 via a soft magnetic layer in the perpendicular recording disk.
[0046] It should be noted that when the second pole piece layer 130 is employed, as shown in FIG. 9 , the length of the head assembly 40 between the ABS and the back gap 108 can be shortened so that the write coil frequency can be increased for further increasing the linear bit density of the write head. It should also be understood that the magnetic head assembly may include multiple write coil layers which are stacked one above the other instead of a single write coil layer, as shown in FIG. 6 , and still be within the spirit of the invention. In addition, the relative location and orientation of the write and read portions of the head may also vary.
Method of Making
[0047] FIGS. 11A and 11B to FIGS. 22A and 22B illustrate various steps in the fabrication of the magnetic head assembly 40 shown in FIGS. 6 and 7 . In FIGS. 11A and 11B the first and second shield layers 80 and 82 may be fabricated by well-known frame plating techniques and the first and second read gap layers 76 and 78 and the sensor 74 may be fabricated by well-known vacuum deposition techniques.
[0048] In FIGS. 12A and 12B a thick alumina layer is deposited (not shown) and the thick alumina is chemically mechanically polished (CMP) to the first pole piece layer (P 1 ) 100 leaving alumina layers 200 and 202 on each side of the first pole piece layer as shown in FIG. 12B . Next, the insulation layer 114 , such as alumina, is deposited for insulating a subsequent write coil layer 112 from the first pole piece layer 100 . The write coil layer 112 is then formed and is insulated by insulation 116 which may be baked photoresist. After photopatterning (not shown) and ion milling down to the first pole piece layer 100 the back gap 108 is formed. This is followed by depositing a thick layer of alumina 119 . In FIGS. 13A and 13B the magnetic head is CMP flat and an isolation layer 118 , which may be alumina, is deposited and patterned so as to leave the back gap 108 exposed.
[0049] In FIGS. 14A and 14B the second pole piece (P 2 ) layer 130 is formed with a front end 134 which is recessed from the ABS and the back gap portion 106 which is magnetically connected to the back gap 108 . In FIGS. 15A and 15B a thick alumina layer is deposited (not shown) and CMP flat leaving the alumina layer 140 between the front end 134 of the second pole piece layer and the ABS. In FIGS. 16A and 16B a pole tip forming layer (PT forming layer) 204 is formed on the second pole piece layer 130 and the alumina layer 140 which provides a form for fabricating the pole tip layer 132 with the pole tip 138 which will be discussed in more detail hereinafter. The mask may be Mo, W, Ta 2 O 3 , SiON X , SiO 2 or Si 3 N 4 and is etchable by a fluorine based reactive ion etching (RIE). In FIGS. 17A and 17B an adhesion/stop layer 206 is formed on the PT forming layer 204 followed by a photoresist layer 208 which is photopatterned to define a shape of the second pole tip layer 132 which includes the perpendicular recording pole tip 138 , as shown in FIG. 6 .
[0050] The adhesion/stop layer 206 is tantalum (Ta). A Ta adhesion/stop layer provides all of the desirable attributes as described hereinabove. In FIGS. 18A and 18B a fluorine based reactive ion etch is implemented into the adhesion/stop layer and into the PT forming layer for producing a slanted profile for the pole tip 138 as shown in FIG. 7 . An aspect of this invention is that both of the adhesion/stop layer 206 and the PT forming layer 204 can be etched by the same fluorine based RIE step. As can be seen from FIGS. 18A and 18B a trench is formed for the second pole tip layer. In FIGS. 19A and 19B a seed layer 210 is sputter deposited into the trench as well as on the front and rear pedestals or the trench may be filled with a ferromagnetic material, such as CoFe, by sputtering (not shown). In FIGS. 20A and 20B plating is implemented to fill the trench to a level slightly above the front and rear pedestals. In FIGS. 21A and 21B CMP is implemented until the CMP stops on the adhesion/stop layer 206 . In FIGS. 22A and 22B , optionally, fluorine based RIE may be implemented to remove any remaining portions of the hard mask layer. A thick alumina layer may then be deposited (not shown) and the magnetic head planarized leaving an alumina layer 212 as shown in FIG. 6 . A capping layer 214 , as shown in FIG. 6 , may then be formed of any suitable material such as alumina.
Perpendicular Recording Pole Tip
[0051] The perpendicular recording pole tip 138 , as shown in FIG. 21B , is enlarged substantially in FIG. 23 . FIG. 23 shows the seed layer 210 which is employed when the pole tip 138 is plated. As shown in FIGS. 6 and 23 , the pole tip is bounded by oppositely facing ABS and back surfaces, top and bottom surfaces 216 and 218 and, with the seed layer 210 , first and second side surfaces 216 and 218 . As shown in FIG. 23 , edge surfaces of layer portions 206 of the adhesion/stop seed layer interface first and second top side surface portions 220 and 222 . Because of the good adhesion between the adhesion/stop seed layer portions 206 and the pole tip 138 there is no delamination at the interfaces 220 and 222 during the CMP step in FIGS. 21A and 21B . FIG. 24 is the same as FIG. 23 except the pole tip 138 has been sputter deposited which eliminates the need for the seed layer 210 shown in FIG. 23 .
Discussion
[0052] It should be understood that vacuum deposition may be employed in lieu of the aforementioned frame plating step. Further, in a broad concept of the invention the pole tip layer can be employed without the aforementioned bottom second pole piece layer. The materials of the various layers are optional in some instances. For instance, photoresist may be employed in lieu of the alumina layers and vice versa. Further, while the magnetic head is planarized at various steps, planarization may occur only for the second pole piece and pole tip layers. Further, the magnetic head assembly may be a merged or piggyback head, as discussed hereinabove. The pole pieces are ferromagnetic materials and are preferably nickel-iron. It should be noted that the second pole piece layer may be a different ferromagnetic material than the pole tip layer. For instance, the second pole piece layer may be Ni 45 Fe 55 and the pole tip layer may be Ni 80 Fe 20 .
[0053] Clearly, other embodiments and modifications of this invention will occur readily to those of ordinary skill in the art in view of these teachings. Therefore, this invention is to be limited only by the following claims, which include all such embodiments and modifications when viewed in conjunction with the above specification and accompanying drawings. | The method of making a magnetic head assembly includes forming a second pole piece layer that is recessed from a head surface, forming a reactive ion etchable (RIEable) pole tip forming layer on the second pole piece layer, forming an adhesion/stop layer of tantalum (Ta) on the pole tip forming layer, forming a photoresist mask on the adhesion/stop layer with an opening for patterning the adhesion/stop layer and the pole tip forming layer with another opening, reactive ion etching (RIE) through the opening to form the other opening, forming the second pole piece pole tip in the other opening with a top which is above a top of the adhesion/stop layer and chemical mechanical polishing (CMP) the top of the second pole piece pole tip until the CMP contacts the adhesion/stop layer. The invention also includes the magnetic head made by such a process. | 8 |
CROSS-REFERENCE TO A RELATED APPLICATION
[0001] The invention described and claimed hereinbelow is also described in German Patent Application DE 102005030537.7 filed on Jun. 30, 2005. This German Patent Application, whose subject matter is incorporated here by reference, provides the basis for a claim of priority of invention under 35 U.S.C. 119(a)-(d).
BACKGROUND OF THE INVENTION
[0002] The invention is based on a lubricating device, in particular a handheld power tool lubricating device, for lubricating a tool unit.
[0003] A lubricating device for lubricating a tool receptacle of a handheld power tool has already been proposed, having a lubricant tube and a means for distributing the lubricant in the tool receptacle.
SUMMARY OF THE INVENTION
[0004] The invention is based on a lubricating device, in particular a handheld power tool lubricating device, for lubricating a tool unit, having a lubricating unit.
[0005] It is proposed that the lubricating unit is intended for using a damming motion for lubricating the tool unit. An automatic lubrication of the tool unit, which is advantageous for the service life of the tool unit, can be attained by a suitable embodiment of the invention.
[0006] “Automatic” lubrication should be understood in particular to mean lubrication that can be done without intentional action on the part of a user. Moreover, a “damming motion” should be understood to mean in particular a motion by which the tool unit can be put into or out of a dammed state or into or out of a storage state, such as inserting or removing the tool unit or introducing or removing a power tool, to which the tool unit is secured, into or out of a storage unit, closing and/or opening a storage unit in which the tool unit is disposed, and so forth.
[0007] The tool unit may be formed by a tool receptacle, such as a drill chuck, clamping tongs, a clamping flange, and so forth, and/or by an insert tool, such as a drill and so forth. The term “intended” should be understood in particular to mean “equipped” and/or “designed”.
[0008] Advantageously, the lubricating device has a coupling region which is intended for coupling with the tool unit. The coupling region can advantageously be adapted to the tool unit, and in particular, effective contact lubrication of a region of the tool unit contacting the coupling region can be achieved. A readily perceptible additional use is also created.
[0009] If the coupling region is embodied as a receiving region for receiving the tool unit, then advantageous protection of the tool unit can additionally be attained, and unwanted spreading of a lubricant upon lubrication can be avoided.
[0010] It is also proposed that the lubricating unit is intended for lubricating the tool unit upon a motion of the tool unit relative to the coupling region. As a result, energy from the coupling motion can advantageously be utilized to drive the lubricating unit, and an additional drive device for the lubricating unit can be avoided. Upon coupling of the tool unit to the coupling region, a pressure force exerted by the tool unit on the lubricating unit can advantageously be utilized for driving a lubricant spray system.
[0011] Another advantageous utilization of a motion of the tool unit relative to the coupling region, specifically with a view to uniform lubrication of large regions of the tool unit, can be attained in that the coupling region includes a guide face, which is intended for guiding the tool unit and which has at least one lubrication portion. As a result, a compact design of the lubricating device is furthermore achieved, since a surface intended for guidance is advantageously utilized for lubrication purposes.
[0012] A further increase in the compactness of the lubricating device can be attained by providing that it has a lubricant conduit unit, which is intended for carrying a lubricant and has an outer face which is embodied as a coupling region. To enable lubricating an interior region of the tool unit, the lubricant conduit unit, upon coupling of the tool unit to the coupling region, can engage an interior region of the tool unit. In an embodiment of the tool unit as a tool receptacle, this is especially suitable; the lubricant conduit unit can engage an interior region of the tool receptacle that is intended to receive a tool.
[0013] In a further feature of the invention, it is proposed that the lubricating device has a securing device for securing the lubricating unit to a storage unit that is intended for storing a handheld power tool. As a result, lubrication of a tool unit secured to a handheld power tool can be achieved, and the handheld power tool can be placed in a region intended for it to be set aside in. The storage unit can advantageously be embodied as a carrying unit for the handheld power tool. The securing device makes for excellent stability of the lubricating device, for instance when the hand held power tool is being put away or removed and/or when the storage unit is being carried around.
[0014] Accessibility to the coupling region, especially upon coupling of the tool unit, secured to the handheld power tool, to the coupling region, can be enhanced in a simple way if the lubricating device has a bending element, which is intended to enable a motion of the coupling region relative to the storage unit when a lubricating unit is secured to the storage unit. The bending element can be embodied as a spring element, such as an elastic plastic part, as a metal spiral spring, and so forth, and/or as a flexible element, such as a film hinge.
[0015] To prevent damage to a coupling region that is movable in the storage unit, the lubricating device has a limiting device, which is intended to limit a relative motion between the coupling region and the storage unit when a lubricating unit is secured to the storage unit.
[0016] It is also proposed that the lubricating unit has a sponge means. As a result, especially uniform lubrication of a region of the tool unit can be attained, since the sponge means, which is for instance of felt, can because of its high absorption be saturated with lubricant, and no additional saturation operation has to be performed.
[0017] The novel features which are considered as characteristic for the present invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 shows a carrying case with a lubricating device in accordance with the present invention and a hammer drill placed in it;
[0019] FIG. 2 shows the carrying case of FIG. 1 , with the lubricating device in accordance with the present invention and a tool holder received in the lubricating device, in a sectional view; and
[0020] FIG. 3 shows the carrying case of FIG. 1 with an alternative lubricating device in accordance with the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] FIG. 1 shows a storage unit 10 , embodied as a handheld power tool carrying unit, with a lid 12 of the carrying case and a base 14 of the carrying case, in which base a handheld power tool 16 , embodied as a hammer drill, is placed. A lubricating device, embodied as a tool holder receptacle 18 , is secured to the base 14 of the carrying case, and a tool unit 20 of the hammer drill 16 , the tool unit being embodied as a tool holder, is received in this lubricating device.
[0022] The lubricating device, which is shown in further detail in a sectional view in FIG. 2 , has a lubricating unit 22 . This unit includes a securing device 24 , with a bottom plate 30 secured to the base 14 of the carrying case by securing means 26 , 28 ; a plastic bending element 32 ; a lubricant tank 34 with a lid 36 ; a lubricant conduit unit 38 , embodied as a lubricating bolt, for carrying a lubricant; and a cap 40 . An inner face of this cap 40 forms a coupling region 42 , which is embodied as a receiving region for receiving the tool unit 20 .
[0023] A further coupling region 44 is formed by an outer face of the lubricant conduit unit 38 and is coupled to an interior region 46 of the tool unit 20 . The coupling region 44 is also embodied as a guide face, which serves to guide the tool unit 20 and has a lubrication portion 48 ; the lubrication portion 48 is formed by a circumferential surface of an annular sponge means 50 embodied as a felt element. Because of this embodiment of the coupling region, a damming motion, which in this exemplary embodiment is placement of the hammer drill 6 into or its removal from the storage unit 10 , is utilized for lubricating the interior region 46 .
[0024] The bending element 32 , which is embodied as a plastic spring element, is in a tensed state and exerts a spring restoring force on the cap 40 when a tool unit 20 is being received in the cap 40 . The cap 40 , the lubricant tank 34 , and the lubricant conduit 38 , which are rotatably supported about a pivot point X, rotate by an angle a as a result of the spring restoring force into a receiving position P, when the tool unit 20 is being removed, which offers easy access to the coupling region 42 , embodied as a receiving region, the next time the handheld power tool 16 is placed in the storage unit 10 .
[0025] The lubricating unit 22 is moreover braced in the storage unit 10 by ribs 52 , 53 , which offer great stability to the lubricating unit 22 , especially if the storage unit 10 is loaded by strong pulses, such as if it falls down. To prevent damage to the lubricating unit 22 , the lubricating device is provided with a limiting device 54 . To that end, the rib 53 and the bottom plate 30 are designed such that a motion of the cap 40 relative to the base 14 of the carrying case is limited by an interlock 56 .
[0026] FIG. 3 shows the storage unit 10 with the handheld power tool 16 placed in it; this storage unit 10 is provided with an alternative lubricating device. This lubricating device has a lubricating unit 58 , which includes a spray system 60 , secured in the base 14 of the carrying case, and a bolt 62 , secured to the lid 12 of the carrying case. The spray system 60 has a pushbutton 64 , a lubricant tank 66 , and a spray conduit 68 with a coupling region 70 , which engages the interior region 46 of the tool unit 20 ( FIG. 2 ).
[0027] Because of this embodiment, a damming motion, which in this exemplary embodiment is the closure of the storage unit 10 , is utilized for lubricating the tool unit, specifically because pressing of the bolt 62 onto the pushbutton 64 causes a lubricant to be sprayed into the tool unit 20 .
[0028] It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types described above.
[0029] While the invention has been illustrated and described as embodied in a lubricating device, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.
[0030] Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention. | A lubricating device for lubricating a tool unit includes a lubricating unit, wherein the lubricating unit is configured for using a damming motion for lubricating the tool unit. | 1 |
REFERENCE TO EARLIER APPLICATIONS
This application is a continuation-in-part of two earlier applications of mine:
1. Ser. No. 577,324 Filed May 14, 1975 for MIXING DISPENSER APPARATUS now abandoned.
2. Ser. No. 577,322, Filed May 14, 1975 for DISPENSING DEVICE.
The disclosures of these two applications are hereby incorporated by reference into this disclosure.
BACKGROUND OF THE INVENTION
In the art directed to disposable syringes, it is known to provide a collapsable container for expressing medicines and the like through a needle, into humans or animals, for example. In my earlier U.S. Pat. No. 3,192,925, a previous development of mine set forth many of the parameters and utilities for devices of this type.
In administering medical injections it is frequently impossible to determine the precise location of the tip of the injection needle after it has been inserted into a patient. In many instances it is important to know whether the tip of the needle has lodged in a vein or an artery. In a conventional hypodermic syringe and needle, it has been a practice for some time for the person administering the injection to withdraw the plunger of the hypodermic syringe after the needle has been inserted into a patient to determine whether any blood wells up into the syringe. If the medication in the syringe is intended to be administered intravenously, the blood welling into the syringe indicates that the tip of the injection needle has lodged in a desired location-either an artery or a vein. If the intent was to deliver the medication into the muscle or subcutaneously, the person administering the injection would withdraw the injection needle and insert it into the patient in another location.
Prior Art disposable syringes are so constructed that it is not possible to create a negative pressure differential on the end of the injection needle to facilitate the withdraw of blood from the patient. In such syringes, the medication is expressed into the patient by squeezing a container which is configured much like the conventional toothpaste tube. Accordingly, it is not possible to manipulate the container itself to create a negative pressure within the container.
THE PRESENT INVENTION
The present invention is therefore principally addressed to providing a dispensing container of the syringe type which is adapted to facilitate determining whether the injection needle has lodged in an artery or vein of the patient to whom an injection is being administered.
To this end, a sealed chamber within the body of the syringe maintains a negative pressure differential which is applied to the end of the injection needle when said end is inserted into the chamber by penetrating a sealed orifice in the wall of the chamber. The sealed chamber has a transparent window to allow the person administering the injection to determine whether or not blood has welled up into the needle after the lower differential pressure has been applied to the open end of the needle. After the location of the tip of the injection needle has been ascertained, the needle body can be moved into communication with a container of medicant which is then expressed into the patient.
Frictional stops are provided to hold the injection needle in three specific positions during the injection procedure. In a first position, the open end of the injection needle is maintained out of communication with the sealed chamber and the container of injectible medication, while being inserted into the patient. In a second position, the open end of the injection needle is within the sealed chamber to facilitate welling up of blood into the container. In the third position, the open end of the needle is within the container of injectible medicant to allow expression of the medicant into the patient.
As has been disclosed in the earlier references cited above, there are particular advantages afforded by a disposable syringe with a collapsable container, as opposed to a hypodermic-type syringe. My present invention combines the advantages of the disposable syringe which employs a collapsable container, with the capability for determining the location of the tip of the injection needle, to provide a unique dispensing device.
Accordingly, it is a primary object of this invention to provide a novel syringe preferably of the disposable type.
It is a further object of this invention to provide a disposable syringe adapted to automatically determine whether the injection needle has been inserted into a vein or artery of a patient.
It is a further object of this invention to provide a syringe wherein the injection needle is held by frictional stops in various specific positions to facilitate the administration of medical injectibles into a patient. Other objects and advantages of the present invention will be readily apparent to those skilled in the art by a reading of the following brief descriptions of the drawings, detailed description of the preferred embodiment, and the appended claims.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective illustration of the disposable syringe;
FIG. 2 is a cross sectional view of the disposable syringe showing one of the alternate positions of this syringe in phantom;
FIG. 3 is a cross sectional view of the disposable syringe illustrated in position to dispense medicant.
FIG. 4 is a cross sectional view of the disposable syringe in communication with a mixing syringe.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings in detail, reference is first made to FIG. 1, wherein there is illustrated a disposable syringe in accordance with this invention, generally designated by numeral 100. The syringe 100 includes a flexible wall collapsable container 120, a needle housing assembly 101 with a transparent window 102, a needle carrier 150 and injection needle 151. As shown in FIGS. 2 and 3, protective end cap assembly 160, shown in phantom in FIG. 3, is threaded onto needle carrier 150.
A medicine, serum or the like 130 is provided inside the tubular container 120 as illustrated in FIG. 2. The liquid or other dispensable product 130 is normally present in the container 120 in a slight vacuum or negative pressure and is sealed against bacterial communication from outside the container 120. The overall operation of the dispensing device will now be outlined with reference to FIGS. 2 and 3.
The person administering a medical injection prepares a disposable syringe 100 for use by first removing the protective covering 160 which is threaded onto needle carrier 150. The needle carrier is at that time at its most outward position as illustrated in FIG. 2. Grasping the syringe by needle carrier 150, the needle is then inserted into the patient. The syringe assembly 100 is then moved into the configuration shown in phantom in FIG. 2. In this position, the open end of injection needle 151 has penetrated the sealed orifice 111 and is within the sealed lower pressure chamber 110. This application of a lower pressure differential to the open end of the needle allows blood to well up into the syringe and to be entrapped in sealed chamber 110, if the tip of the needle has lodged in a vein or artery of the patient. The person administering the injection can observe the result of moving the needle from position one to position two by looking through transparent opening 102.
Frictional stops are located within the needle carrier assembly, to allow for a positive fricitional engagement in specific positions. Frictional stop 104, FIGS. 2 and 3, facilitates insertion of the needle into the patient. Frictional stop 103 maintains the needle assembly in position to allow blood to well up into the syringe.
After it has been determined that the tip of the injection needle is in the desired location, needle carrier 150 is moved into the third position illustrated in FIG. 3. In this position, the open end of the needle 151 has penetrated a second sealable orifice and is within container 120. Medication 130 can then be expressed into the patient by collapsing the container, expressing the medicant through injection needle 151 into the patient. After the injection has been completed, the syringe is withdrawn from the patient and disposed of.
It will be noted that in the event the tip of the needle is not initially located properly, the process can be repeated until the person administering the injection is satisfied that the tip is properly located. Of course, after the seal to the sealed chamber has been violated, the lower presure differential within the chamber will begin to equalize, and there are a limit to the number of times that the tip of the needle can be relocated before the sealed chamber pressure is equal to atmospheric.
There are times when it may be desirable to mix the medicants to be expressed into the patient immediately before inoculation. To facilitate this as described in considerably more detail in my application Ser. No. 577,324 of which this application is a continuation-in-part, a mixing syringe can be inserted through injection needle 151 as shown in FIG. 4. As illustrated, injection needle 251 passes through neoprene or rubber seals 111 and 112 and extends into container 120. After the mixing has been completed, needle 251 is withdrawn from communication with disposable syringe assembly 100.
As illustrated, sealed chamber 110 is shown as a separate container within needle carrier assembly 101. In a preferred embodiment this sealed chamber 110 is constructed of a transparent material. But it will be appreciated that other configurations then those illustrated might be employed. For example, the sealed compartment could be manufactured as an integral unit with needle carrier assembly 101 and evacuated by some suitable means after manufacture. It will be further noted that the open end of needle 151 is adapted to pierce frangible seals 111 and 112 which may be constructed of any suitable material, such as rubber or neoprene.
As described above, transparent window 102 allows the person administering the injection to observe the contents of sealed chamber 110. Of course, it would be possible to construct sealed chamber 110 and needle housing assembly 101 entirely of transparent materials, such as glass or plastic, in which instance a transparent window would not be necessary.
Even further, it will be understood that various other constructions may be used to embody the concept of the present invention, within the spirit or scope of the claims and as is elsewhere recited as being objectives of the present invention.
It will be apparent from the foregoing that the various objectives of the present invention will be fulfilled. | A method and apparatus for the administration of medical injections. After insertion of an injection needle into a patient, a negative pressure differential is applied to the exposed end of the injection needle so that if the injection needle has been inserted into any artery or a vein, blood will be drawn up into the needle. A transparent window allows the person administering the injection to observe whether any blood has been drawn into the needle. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority from U.S. Provisional Patent Application No. 60/587,120 filed Jul. 12, 2004.
TECHNICAL FIELD
[0002] The present invention relates to a method for extending the mid load range of a gasoline direct-injection controlled auto-ignition combustion engine, and more particularly to the use of a port throttle as an alternative to external exhaust gas recirculation (EGR) to dissipate some of the thermal energy associated with the internal residuals needed for controlled auto-ignition combustion and charge dilution.
BACKGROUND OF THE INVENTION
[0003] To improve the thermal efficiency of gasoline internal combustion engines, dilute combustion, using either air or EGR, is known to give enhanced thermal efficiency and lower NOx emissions. There is, however, a limit at which an engine can be operated with a diluted mixture because of misfire and combustion instability as a result of a slow burn. Known methods to extend the dilution limit include: 1) improving ignitability of the mixture by enhancing ignition and fuel preparation; 2) increasing the flame speed by introducing charge motion and turbulence; and 3) operating the engine under controlled auto-ignition combustion.
[0004] The controlled auto-ignition process is sometimes called a Homogeneous Charge Compression Ignition (HCCI). In this process, a mixture of combusted gases, air, and fuel is created and auto-ignition is initiated simultaneously from many ignition sites within the mixture during compression, resulting in very stable power output and high thermal efficiency. The combustion is highly diluted and uniformly distributed throughout the charge. The burned gas temperature and hence NOx emissions are substantially lower than that of traditional spark ignition engines based on propagating flame front and diesel engines based on an attached diffusion flame. In both spark ignition and diesel engines, the burned gas temperature is highly heterogeneous within the mixture with very high local temperature creating high NOx emissions.
[0005] Engines operating under controlled auto-ignition combustion have been successfully demonstrated in two-stroke gasoline engines using a conventional compression ratio. It is believed that the high proportion of burned gases remaining from the previous cycle, i.e., the residual content, within the two-stroke engine combustion chamber is responsible for providing the high mixture temperature necessary to promote auto-ignition in a highly diluted mixture. In four-stroke engines with traditional valve means, the residual content is low, and controlled auto-ignition at part load is difficult to achieve. Known methods to induce controlled auto-ignition at low and part loads include: 1) intake air heating; 2) variable compression ratio; and 3) blending gasoline with ignition promoters to create a more easily ignitable mixture than gasoline. In all the above methods, the range of engine speeds and loads in which controlled auto-ignition combustion can be achieved is relatively narrow.
[0006] Engines operating under controlled auto-ignition combustion have been demonstrated in four-stroke gasoline engines using variable valve actuation with unconventional valve means. The following is a description of one such unconventional valve strategy. With this valve strategy, a high proportion of residual combustion products from previous combustion cycles is retained to provide the necessary condition for auto-ignition in a highly diluted mixture. The range of engine speeds and loads in which controlled auto-ignition combustion can be achieved is greatly expanded using a conventional compression ratio.
[0007] A method of operating a four-stroke internal combustion engine has been disclosed in which combustion is achieved at least partially by an auto-ignition process. Flow of premixed fuel/air charge and combusted gases is regulated by hydraulically controlled valve means in order to generate conditions in the combustion chamber suitable for auto-ignition operation. The valve means used includes an intake valve controlling flow of premixed fuel/air mixture into the combustion chamber from an inlet passage and an exhaust valve controlling flow of exhaust combusted gases from the combustion chamber to an exhaust passage. The exhaust valve is opened for two separate periods during the same four-stroke cycle. The exhaust valve is opened for a first period to allow combusted gases to be expelled from the combustion chamber and for a second period to allow combusted gases previously exhausted from the combustion chamber to be drawn back into the combustion chamber. The double opening of the exhaust valve during each four-stroke cycle, creates the necessary condition for auto-ignition in the combustion chamber. This is generally referred to as an exhaust re-breathing valve strategy.
[0008] A method of operating a four-stroke internal combustion engine has also been disclosed in which combustion is achieved at least partially by an auto-ignition process. Flow of air and combusted gases are regulated by hydraulically controlled valve means as detailed above. The fuel, however, is delivered by a gasoline injector directly into the combustion chamber. The gasoline injector is said to inject fuel either during the intake stroke or the subsequent compression stroke during a single engine cycle.
[0009] In general, HCCI engine operation is limited by combustion stability at low engine load and by in-cylinder pressure rise or amplitude of pressure oscillation at a mid load limit. Too large a pressure rise or amplitude of pressure oscillation results in combustion generated noise called ringing. It has been found experimentally that both internally and externally recirculated burned gas is effective in controlling the combustion rate and hence the pressure rise. The present invention describes a method for regulating the thermal energy of the internally recirculated burned gas or internal residual as an alternative to external EGR for HCCI engine combustion control in the mid load range.
SUMMARY OF THE INVENTION
[0010] The present invention provides a method for extending the mid load range of a gasoline direct-injection controlled auto-ignition combustion engine. More specifically, a port throttle is used as an alternative to external exhaust gas recirculation (EGR) to dissipate some of the thermal energy associated with the internal residuals needed for controlled auto-ignition combustion and charge dilution. The port throttle is achieved by employing a flow control valve in one branch of the intake runners for a two-intake-valve per cylinder engine. The swirl control valve that is currently used in a stratified-charge gasoline direct-injection spark ignition engine for in-cylinder air motion control is used herein for example to demonstrate its effectiveness.
[0011] The present invention works for all valve strategies. For purposes of example, only results obtained using an exhaust re-breathing valve strategy as described above are presented herein. The injection strategy used is single fuel injection during the intake stroke. An overall lean in-cylinder fuel-air mixture is generated by controlling the proportion of fuel and air mass inducted into the cylinder. With this approach, the mid load operation limit is reached around 450 kPa NMEP using a conventional compression ratio as determined by either a pressure rise or an amplitude of pressure oscillation that exceeds a prescribed threshold value.
[0012] It is found experimentally that variation of the flow control valve setting or the degree of port throttle in one branch of the intake runners has a profound effect on combustion rate of controlled auto-ignition combustion engines. In particular, the peak burning rate decreases and bum duration increases with decreasing flow control valve setting from open to close. It is further experimentally demonstrated that the observed combustion rate decrease with port throttling is not caused by changes in the in-cylinder mixture motion, i.e. the mixing process, as originally speculated. In fact, both peak burning rate and burn duration are the same for the case without the port throttle and the case with the intake valve connecting to the throttled port deactivated.
[0013] One-dimensional gas dynamic modeling analyses revealed that, for the case with the flow control valve closed, a large portion of the total recirculated burned gas in the cylinder is drawn from the cooler throttled intake port (about 440 deg K gas temperature) instead of re-breathing fully from the hotter exhaust port (about 740 deg K gas temperature). This results in a lower mixture temperature at intake valve closing (IVC), hence retarded and slower HCCI combustion. The effectiveness of using a port throttle for thermal management of the recirculated burned gas varies depending on port throttle setting. The effect is the strongest when the flow control valve is fully closed.
[0014] With the present invention, the mid load range of a gasoline direct-injection controlled auto-ignition combustion engine is expanded by closing the flow control valve to take advantage of the maximum heat dissipation of the recirculated burned gas in the throttled intake port. In particular, the mid load range is increased by more than 5% to about 475 kPa NMEP using a conventional compression ratio with acceptable pressure rise or amplitude of pressure oscillation.
[0015] These and other features and advantages of the invention will be more fully understood from the following description of certain specific embodiments of the invention taken together with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1A is a schematic view of a single cylinder direct-injection gasoline four-stroke internal combustion engine according to the present invention;
[0017] FIG. 1B is a top schematic view showing the valve arrangement of the engine of FIG. 1A ;
[0018] FIG. 2 is a graph of valve lift profiles as a function of crank angle for exhaust and intake valves of a four-stroke controlled auto-ignition combustion engine operating with an exhaust re-breathing valve strategy via use of a mechanical cam-actuated valve system;
[0019] FIG. 3 is a graph of variations in heat release rate as a function of flow control valve setting using an exhaust re-breathing valve strategy at 2000 rpm, 11 mg/cycle, and A/F=20 for fully premixed engine operation;
[0020] FIG. 4A illustrates a port deactivation intake configuration achieved by closing the flow control valve;
[0021] FIG. 4B illustrates an intake valve deactivation intake configuration achieved by removing the finger follower of the intake valve connecting to the SCV port;
[0022] FIG. 5 shows graphs of variations in heat release rate for the two intake configurations shown in FIG. 4 together with the SCV open case for both fully premixed and direct-injection engine operations at 2000 rpm, 11 mg/cycle, and A/F=20;
[0023] FIG. 6 shows graphs of variations in measured cylinder pressure during the gas exchange period for the two intake configurations shown in FIG. 4 for both fully premixed and direct-injection engine operations at 2000 rpm, 11 mg/cycle, and A/F=20;
[0024] FIG. 7 shows graphs of variations in measured (experiment) and calculated (1-D modeling) cylinder pressure during the gas exchange period for the three intake configurations examined together with the valve lift profiles for both fully premixed and direct-injection engine operations at 2000 rpm, 11 mg/cycle, and A/F=20;
[0025] FIG. 8 shows graphs of calculated (1-D modeling) gas velocity in both SCV and straight intake ports 2 cm upstream of the respective intake valves during the gas exchange period for the three intake configurations examined together with the valve lift profiles for engine operations at 2000 rpm, 11 mg/cycle, and A/F=20;
[0026] FIG. 9 shows graphs of calculated (1-D modeling) residual flow rate in both SCV and straight intake ports 2 cm upstream of the respective intake valves during the gas exchange period for the three intake configurations examined together with the valve lift profiles for engine operations at 2000 rpm, 11 mg/cycle, and A/F=20;
[0027] FIG. 10 shows graphs of calculated (1-D modeling) mass fraction of residual in both SCV and straight intake ports 2 cm upstream of the respective intake valves during the gas exchange period for the three intake configurations examined together with the valve lift profiles for engine operations at 2000 rpm, 11 mg/cycle, and A/F=20;
[0028] FIG. 11 shows graphs of calculated (1-D modeling) gas temperature in both SCV and straight intake ports 2 cm upstream of the respective intake valves during the gas exchange period for the three intake configurations examined together with the valve lift profiles for engine operations at 2000 rpm, 11 mg/cycle, and A/F=20;
[0029] FIG. 12 shows graphs of measured combustion performance as a function of fueling rate for two SCV settings (36 vs. 20 deg) at 2000 rpm and A/F=20 for direct-injection engine operation; and
[0030] FIG. 13 is a graph of variations in heat release rate as a function of flow control valve setting and fueling rate at 2000 rpm and A/F=20 for direct-injection engine operation.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0031] For simplicity, the following description will address the present invention in its application to a single cylinder direct-injection gasoline four-stroke internal combustion engine, although it should be appreciated that the present invention is equally applicable to a multi-cylinder direct-injection or port-fuel-injected gasoline four-stroke internal combustion engine.
[0032] A schematic representation of an embodiment of the present invention is a single-cylinder direct-injection four-stroke internal combustion engine 10 shown in FIG. 1A . In the Figure, a piston 12 is movable in a cylinder 14 and defines with the cylinder 14 a variable volume combustion chamber 16 . An intake passage 18 supplies air into the combustion chamber 16 . Flow of air into the combustion chamber 16 is controlled by intake valve 20 . Combusted gases can flow from the combustion chamber 16 via an exhaust passage 22 and flow of combusted gases through the exhaust passage 22 is controlled by exhaust valve 24 .
[0033] The engine 10 of the present invention as shown in FIG. 1A has a mechanical cam-actuated valve train 26 that controls the opening and closing of both the intake 20 and exhaust 24 valves. The valve train 26 is tied to the position of the engine 10 , which is measured by a rotation sensor 28 . The rotation sensor 28 is connected to a crankshaft 30 of the internal combustion engine 10 . The crankshaft 30 is connected by a connecting rod 32 to the piston 12 reciprocate in the cylinder 14 .
[0034] A gasoline direct injector 34 , controlled by an electronic controller, is used to inject fuel directly into the combustion chamber 16 . The present invention is insensitive to injector tip location. A spark plug 36 , controlled also by an electronic controller, is used to enhance the ignition timing control of the engine 10 across the engine load range. While the simple engine 10 shown above does not need a spark plug 36 for operation under controlled auto-ignition combustion, it has proven desirable to use a spark plug to complement the auto-ignition process, particularly in start-up conditions. Also, it has proven desirable to rely on auto-ignition only in part-load/low speed operating conditions and to use spark ignition during high load/high speed operating conditions.
[0035] FIG. 1A also shows a flow control valve 38 according to the method of present invention. It is located inside one branch of the intake runners 18 for a two-intake-valve per cylinder engine (see FIG. 1B ). An existing swirl control valve that was previously used for in-cylinder air motion control in a stratified-charge gasoline direct-injection spark ignition engine is used herein for example to demonstrate the effectiveness of the present invention. Closing the flow control valve 38 by way of example provides a reservoir chamber inside the intake passage 18 between the flow control valve 38 and the intake valve 20 .
[0036] Control of the motion of the intake valve 20 and exhaust valve 24 in accordance with an exhaust re-breathing valve strategy is illustrated in FIG. 2 for a four-stroke controlled auto-ignition combustion engine 10 using a mechanical cam-actuated valve system. In the figure, the exhaust valve 24 is opened twice during 720 degrees rotation of the crankshaft 30 , i.e. one engine cycle. During the first period of opening, combusted gases are expelled from the combustion chamber 16 to the exhaust passage 22 . During the second period of opening, previously exhausted combusted gases are drawn back into the combustion chamber 16 from the exhaust passage 22 at the same time as air or fuel/air charge is drawn into the combustion chamber 16 through the inlet passage 18 . Thus, mixing of combusted gases and air or fuel/air charge is achieved and promotes the correct conditions for auto-ignition.
[0037] Auto-ignition of the mixture of combusted gases, air and either premixed or direct-injected fuel occurs after compression of the mixture during the compression stroke. The combustion of the mixture then causes the gases to expand in the power stroke. The four-stroke cycle then starts again. In particular, for the engine operating conditions examined, the exhaust valve 24 is opened for the first time during an engine cycle at roughly 60 degrees before bottom dead center at the end of the expansion stroke. The exhaust valve 24 is then closed for the first time near the end of the exhaust stroke. The intake valve 20 is opened before the end of the exhaust stroke and the exhaust valve 24 is re-opened about 30 degrees after the end of the exhaust stroke. The exhaust valve 24 is closed again near the end of the intake stroke while the intake valve 20 is closed approximately 60 degrees after the end of the intake stroke.
[0038] FIG. 3 shows variations in heat release rate as a function of flow control valve setting using an exhaust re-breathing valve strategy at 2000 rpm, 11 mg/cycle, and A/F=20 for fully premixed engine operation. It is clear from the figure that the heat release rate is sensitive to flow control valve settings. In particular, the onset of ignition is more retarded and bum duration is much increased when the flow control valve 38 is closed.
[0039] Two hypotheses were proposed as to what causes later and slower combustion when the flow control valve is closed: 1) Increased heat loss due to intensified charge motion with flow control valve 38 closed; and 2) charge storage in the SCV port during a compression stroke and subsequent re-induction into the cylinder during the intake stroke of next cycle.
[0040] As shown in FIGS. 4A and 4B , two hardware configurations were examined to address the issue. FIG. 4A shows a port deactivation configuration, achieved by closing the flow control valve 38 ; and FIG. 4B shows a valve deactivation configuration, achieved by removing the finger follower of the intake valve 20 controlling communication with the SCV port.
[0041] FIG. 5 shows variations in heat release rate for the two intake configurations shown in FIGS. 4A and 4B together with the SCV open case for both fully premixed and direct-injection engine operations at 2000 rpm, 11 mg/cycle, and A/F=20. The following is clear from the figure. 1) The burn rates are identical between the case with the flow control valve 38 open (SCV 90 ) and the case with one intake valve 20 deactivated. This finding eliminates the first hypothesis from further consideration since the in-cylinder charge motion varies greatly between the two intake configurations. 2) The fact that the burn rates are very different between port deactivation (SCV 20 ) and one intake valve 20 deactivated points towards a charge storage effect in the SCV port. To fully understand the charge storage effect in the intake port, a one-dimensional gas dynamic engine cycle simulation program was used to calculate flows in and out of the engine cylinders.
[0042] FIG. 6 shows variations in measured cylinder pressure during the gas exchange period for the two intake configurations shown in FIGS. 4A and 4B for both fully premixed and direct-injection engine operations at 2000 rpm, 11 mg/cycle, and A/F=20. These data are used for one-dimensional gas dynamic model validation.
[0043] FIG. 7 shows variations in measured (experimental) and calculated (one-dimensional modeling) cylinder pressure during the gas exchange period for the three intake configurations examined together with the valve lift profiles for both fully premixed and direct-injection engine operations at 2000 rpm, 11 mg/cycle, and A/F=20. It is clear from the figure that agreement between measured and one-dimensional gas dynamic model calculated cylinder pressures is extremely good.
[0044] FIG. 8 shows calculated (one-dimensional modeling) gas velocity in both SCV and straight intake ports 2 cm upstream of the respective intake valves 20 during the gas exchange period for the three intake configurations examined together with the valve lift profiles for engine operations at 2000 rpm, 11 mg/cycle, and A/F=20.
[0045] FIG. 9 shows calculated (one-dimensional modeling) residual flow rate in both SCV and straight intake ports 2 cm upstream of the respective intake valves 20 during the gas exchange period for the three intake configurations examined together with the valve lift profiles for engine operations at 2000 rpm, 11 mg/cycle, and A/F=20.
[0046] FIG. 10 shows calculated (one-dimensional modeling) mass fraction of residual in both SCV and straight intake ports 2 cm upstream of the respective intake valves 20 during the gas exchange period for the three intake configurations examined together with the valve lift profiles for engine operations at 2000 rpm, 11 mg/cycle, and A/F=20.
[0047] FIG. 11 shows calculated (one-dimensional modeling) gas temperature in both SCV and straight intake ports 2 cm upstream of the respective intake valves 20 during the gas exchange period for the three intake configurations examined together with the valve lift profiles for engine operations at 2000 rpm, 11 mg/cycle, and A/F=20.
[0048] One-dimensional modeling results presented in FIGS. 8-11 show the following. 1) The charge trapped in the SCV port has an average residual mass fraction around 38% (left graph of FIG. 10 ). 2) After intake valve opening, this trapped charge flows out of the SCV port into the combustion chamber (left graph of FIG. 9 ). 3) The temperature of this trapped charge is between 390 and 440 degree K (left graph of FIG. 11 ). This is about 300 degree K lower than the gas temperature in the exhaust port (as noted in FIG. 11 ). 4) When the exhaust valve 24 is re-opened around 390 degree ATDC combustion, the SCV port is re-charged with hotter gas from the cylinder 14 and the exhaust port. This storage and discharge of residual gas in the SCV port resulted in an overall reduction of in-cylinder mean charge temperature at the time of intake valve closing as compared to the cases with SCV open and one intake valve 20 deactivated. This causes retarded ignition timing shown in FIG. 3 for the SCV closed case.
[0049] FIG. 12 shows measured combustion performance as a function of fueling rate for two SCV settings (36 vs. 20 degrees) at 2000 rpm and A/F=20 for direct-injection engine operation. When the SCV setting is set at 36 degrees, both peak pressure and maximum rate of pressure rise increase with increasing fueling rate (top plots of FIG. 12 ). At a fueling rate of 13.75 mg/cycle, this corresponds to a load of 450 kPa NMEP, and the maximum rate of pressure rise reaches the limit of 50 bar/msec. By closing the SCV valve, both peak pressure and maximum rate of pressure rise are greatly reduced. The crank angle location of peak pressure is also retarded. This allows for addition of an additional 0.65 mg of fuel (about 25 kPa NMEP load) to the engine 10 before exceeding the maximum rate of pressure rise limit again. The mid load operation limit is thereby extended by about 5 percent.
[0050] FIG. 13 shows variations in heat release rate as a function of flow control valve setting and fueling rate at 2000 rpm and A/F=20 for direct-injection engine operation. The figure further illustrates the effects of flow control valve setting and fueling rate on controlled auto-ignition combustion rate.
[0051] The present invention applies to other engine speeds and valve strategies as well, although the effectiveness of port throttle on residual gas heat rejection, and hence HCCI combustion, may vary. In particular, the present invention should be more effective at lower engine speed due to longer time available for heat dissipation. Further, any valve strategy that renders itself towards using the SCV port for storage and release of residual gas can benefit from present invention for mid load extension.
[0052] The present invention can be extended to include active thermal management in both the intake and exhaust ports. For example, coolant passages in the head can be designed so that wall temperatures of both the SCV and exhaust ports are controlled. This will help in regulating the temperature of recirculated burned gas for HCCI combustion especially in the mid load range.
[0053] The present invention applies equally well to both premixed and direct-injection controlled auto-ignition combustion engines as demonstrated in the above embodiments.
[0054] While the intake valve 20 and exhaust valve 24 in the above embodiments are mechanically actuated, they could be actuated electro-hydraulically or electrically using electromagnetic force.
[0055] While the invention has been described by reference to certain preferred embodiments, it should be understood that numerous changes could be made within the spirit and scope of the inventive concepts described. Accordingly, it is intended that the invention not be limited to the disclosed embodiments, but that it have the full scope permitted by the language of the following claims. | A method is disclosed for expanding the mid load range of a four-stroke gasoline direct-injection controlled auto-ignition combustion engine. The engine includes at least one cylinder containing a piston reciprocably connected with a crank and defining a variable volume combustion chamber including an intake valve controlling communication with an air intake and an exhaust valve controlling communication with an exhaust outlet. A system is employed for variably actuating the intake and exhaust valves. The valve actuating system is employable to operate the intake and exhaust valves with an exhaust re-compression or an exhaust re-breathing valve strategy. A reservoir chamber in communication with the combustion chamber is provided for temporary holding of residual burned gas. Residual burned gas in the combustion chamber and the exhaust outlet enters into the reservoir chamber and then loses thermal energy while in the reservoir chamber before being drawn back into the combustion chamber. | 5 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] Priority is claimed based on U.S. Provisional Application No. 60/310,838, filed Aug. 9, 2001, the entirety of which is incorporated by reference herein.
BACKGROUND OF THE INVENTION
[0002] The present invention relates generally to voice communication systems and, more particularly, to systems for transmitting and receiving voice information over packet-switched networks.
[0003] For years, the telecommunications industry has examined ways to combine the flexibility and functionality of packet-switched networks primarily used for transmitting data (e.g., the Internet) with the accuracy and speed of conventional circuit based telephone networks (i.e., the Public Switched Telephone Network or PSTN). Conventional telephone systems differ from modern data-based computer networks in several ways. Most importantly however, are the differences in how connections between the sender and the recipient are made.
[0004] In conventional telephone systems, when a caller picks up his telephone, an OFFHOOK message is sent from the phone across the PSTN to the user's central office (CO). In response, the CO sends a dialtone back to the user's phone indicated that he is connected and can initiate a call. Next, the caller dials the phone number of the intended recipient and, through the keypad tones or pulses, this information is transmitted to the CO. In response, the CO transmits a RINGING message causing the recipient's phone to ring. If the recipient picks up the phone, the recipient's phone sends an OFFHOOK message to the CO and a dedicated circuit across the PSTN between the caller and the recipient is established, enabling voice traffic to pass between the connected parties in a smooth, seamless manner. Typically, the voice traffic is digitized at the CO and transmitted over the dedicated PSTN circuit using a technology called time division multiplexing (TDM). This dedicated circuit continuously transmits information between the parties at a rate of about 128 kilobits per second (kbps) (64 kbps each way) for the duration of the call. For a five minute telephone call, this equates to the transmission of approximately 4.7 megabytes (MB) of information.
[0005] Unfortunately, in most telephone conversations, much of the bandwidth required to enable the transmission of information between the parties is wasted. For example, because people typically do not speak while the other party is speaking, almost half of the available bandwidth is wasted during the call. Similarly, during periods of silence (even milliseconds at a time), no information needs to pass between the parties. However, because of the dedicated, physical circuit between the parties, information is passed regardless of content.
[0006] Contrary to conventional telephone systems, most data networks such as the Internet, do not transmit information across dedicated, physical circuits. Rather, information sent between two computers on a network is broken up in a series of small packets. These packets are then routed to the destination and reassembled at the recipient end. Various protocols have been developed for enabling the efficient and accurate transfer of information across computer networks, such as internet protocol (IP), asynchronous transfer mode (ATM), Ethernet, etc. Because computer networks only transmit the information which needs to be relayed, there is little wasted bandwidth.
[0007] Because of the rising need for network bandwidth and the continued need to optimize bandwidth which is already available, efforts have been made to reduce the bandwidth cost of voice traffic by routing voice traffic over packet-switched networks. This concept is generally referred to as voice over IP telephony, although various other network protocols may also be employed. In general, the concept of voice over IP telephony requires a seamless experience on the part of the user. That is, conventional telephone systems (referred to as plain old telephone systems or POTS) must be able to utilize the technology in an invisible manner. In practice, similar to conventional PSTN devices, when a POTS device (or analogous customer premises equipment (CPE) telecommunications device) goes off hook, a message is sent to a CO indicating this state. A dialed number is then received by the CO, indicating the recipient's address, and the corresponding voice traffic is digitized and packetized at the CO for transmission to the recipient's CPE device. Unfortunately, because voice transmissions generally require a smooth flow of information, the packets must be transmitted, received, and reassembled in substantially real-time. Many modern computer network protocols fail to consistently meet acceptable standards in this respect, resulting in packet loss and discard, often rendering voice communication choppy or delayed. What was needed was a network protocol which could guarantee the consistent real-time transmission of voice traffic.
[0008] In response to this need, the Telecommunications Standardization Sector of the International Telecommunication Union (ITU-T) and others have developed protocols (e.g., I.363.1 and I.366.2) for facilitating voice over ATM transmission using layers 1 and 2 of the ATM Adaptation Layer (AAL) model, as a technology capable of the high speed transfer of voice data across public packet-switched networks, such as the Internet. ATM utilizes very large-scale integration (VLSI) technology to segment data into individual packets having a fixed size of 53 bytes or octets. These packets are commonly referred to as cells. Unlike other types of networking protocols, ATM does not rely upon Time Division Multiplexing in order to establish the identification of each cell. That is, rather than identifying cells by their time position in a multiplexed data stream, ATM cells are identified solely based upon information contained within the cell header.
[0009] Further, ATM differs from system based upon conventional network architectures such as Ethernet or Token Ring in that rather than broadcasting data packets on a shared wire for all network members to receive, ATM cells dictate the successive recipient of the cell through information contained within the cell header. That is, a specific routing path through the network, called a virtual path (VP) or virtual circuit (VC), is set up between two end nodes before any data is transmitted. Cells identified with a particular virtual circuit are delivered to only those nodes on that virtual circuit. In this manner, only the destination identified in the cell header receives the transmitted cell. Further, this concept enables bandwidth to be specifically allocated to the VP or VC handling the voice communication.
[0010] The backbone of an ATM network consists of switching devices capable of handling the high-speed ATM cell streams. The switching components of these devices, commonly referred to as the switch fabric, perform the switching function required to implement a virtual circuit by receiving ATM cells from an input port, analyzing the information in the header of the incoming cells in real-time, and routing them to the appropriate destination port. Millions of cells per second are switched by a single device.
[0011] Importantly, this connection-oriented scheme permits an ATM network to guarantee the minimum amount of bandwidth required by each connection. Such guarantees are made when the connection is set-up. When a connection is requested, an analysis of existing connections is performed to determine if enough total bandwidth remains within the network to service the new connection at its requested capacity. If the necessary bandwidth is not available, the connection is refused.
[0012] In order to achieve efficient use of network resources, bandwidth is allocated to established connections under a statistical multiplexing scheme. Therefore, congestion conditions may occasionally occur within the ATM network resulting in cell transmission delay or even cell loss. To ensure that the burden of network congestion is placed upon those connections most able to handle it, ATM offers multiple grades of service, such as variable bit rate (VBR), real-time VBR, unspecified bit rate (UBR), and constant bit rate (CBR). These grades of service support various forms of traffic requiring different levels of cell loss probability, transmission delay, and transmission delay variance, commonly known as delay jitter. This system enables voice traffic to be prioritized over other, less time sensitive forms of data transmission.
[0013] Although significant advancements in Voice over ATM telephony and other forms of voice over packet-switched network technologies have been developed, significant improvements are required prior to the general adoption of this methodology. Accordingly, vendors and developers in this area must continually develop and test new applications for performing the functions required to transmit voice traffic acceptably over packet-switched networks. Unfortunately, this above described protocols, and the various software and hardware systems designed to implement them, conventionally require that a large portion of the data processing be performed at the CO location, thus resulting in an asymmetrical relay of information between parties. In this setting, all information relayed between a caller and a recipient must first be filtered through the CO. However, during design, testing and development, inclusion of a CO may be unnecessary, unavailable, expensive or even unacceptable, for confidentiality reasons. Further, it may desirable to simply carry out low-level testing to determine if the designed major hardware/software blocks work well together.
[0014] Accordingly, it is desired to provide a system and method for enabling customer devices to symmetrically transmit voice information between themselves without requiring intervention on the part of a CO.
SUMMARY OF THE INVENTION
[0015] The present invention overcomes the above-described problems and deficiencies by providing a system and method for providing symmetrical connectivity between at least two consumer premises equipment (CPE) telecommunications devices is provided. At least two consumer premises equipment telecommunications devices are operatively connected over an asynchronous transfer mode telecommunications network. The at least two consumer premises equipment telecommunications devices are configured to perform local tone generation, local tone detection and decoding, and direct transfer and decoding of dialed digits using channel associated signaling (CAS) secondary service packets and dialed digit packets to transition between various states.
[0016] In accordance with one embodiment of the present invention, CAS packets include 8 bytes of information and dialed digit packets include 9 bytes of information. Further, signaling messages transported using the CAS packets preferably include the following: TALK, TEARDOWN, RINGING, BUSY, and ERROR. The above signaling messages as well as local events trigger transitions between various states including the following: ONHOOK, OFFHOOK, DIALTONE, RINGING, RINGBACK, and TALKING.
[0017] By providing symmetrical connectivity of CPE devices, central office involvement may be eliminated.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The present invention can be understood more completely by reading the following Detailed Description of the Preferred Embodiments, in conjunction with the following drawings.
[0019] [0019]FIG. 1 is a block diagram illustrating both conventional asymmetrical and inventive symmetrical telephony systems.
[0020] [0020]FIG. 2 is a flow chart describing one exemplary exchange of messages in a conventional telephony signaling scheme.
[0021] [0021]FIG. 3 is a block diagram illustrating the transitions between various system states.
[0022] [0022]FIG. 4 is a flow chart describing a method for setting up a voice call utilizing the signaling scheme of the present invention.
[0023] [0023]FIG. 5 is a flow chart describing a method for tearing down a voice call utilizing the signaling scheme of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0024] Referring generally to figures and, in particular, to FIG. 1, there is shown a block diagram 100 illustrating both a conventional asymmetrical packet-switched telephony system as well as one embodiment of the symmetrical packet-switched telephony system of the present invention, with dashed lines indicated convention systems and the solid line indicating the system of the present invention. In particular, diagram 100 includes a first CPE device 102 and a second CPE device 104 . It should be understood that the CPE devices described herein may be or include any of the following: a telephone, a fax machine, a modem (e.g., digital subscriber line, coaxial cable, phone), private branch exchange (PBX), or any other integrated access device (IAD) for performing packetization of voice traffic and associated functionalities. In conventional packet-switched telephony systems, sending information from the first CPE device 102 to the second CPE device requires the intervention of at least one CO device 106 . Typically, multiple CO devices are required in that the respective CPE devices operate in different locations and are controlled by respective CO devices.
[0025] In operation, CO device 106 is typically operated by an incumbent local exchange carrier (ILEC) and/or a competitive local exchange carrier (CLEC) and includes, for DSL networks, at least a DSL access multi-plexer (DSLAM), a voice gateway for receiving the packetized voice traffic and formatting it for reception by a class 5 voice switch, and a class 5 voice switch for delivering the formatted voice traffic onto the PSTN. As described in detail above, traditional packet-switched telephony signaling protocols/schemes are typically based on asymmetrical messages, taking place between one of the CPE devices 102 / 104 and the CO device 106 . The purpose of these messages is to establish a (voice or analog data (e.g., fax)) connection between the caller and the callee. These messages are exchanged between the CPE and CO in order to notify each other that specific events have occurred.
[0026] Referring now to FIG. 2, there is shown a flow chart describing one exemplary exchange of messages in a conventional packet-switched telephony signaling scheme. In step 200 , a telephone goes offhook at CPE 102 , and, correspondingly, CPE 102 notifies the CO 106 with a specific offhook message. Typically, this involves packetizing the message at the CPE 102 's IAD, and relaying the packetized message through the CO's DSLAM, voice gateway, and onto the class 5 switch. In response, CO 106 typically generates, in-band, the traditional dial tone and relays it back to the CPE 102 in step 202 . Conventionally, the dial tone is generated by the class 5 switch and relayed back through the network to CPE 102 's IAD and onto the telephone which is offhook. In step 204 , the CPE 102 , in response to the user's input transmits dialed tones representative of CPE 104 's telephone number to the class 5 switch in CO 106 . In step 206 , the CO 106 receives the dialed digits, and in step 208 notifies the CPE 104 of an incoming call. In response, in step 210 the CPE 104 causes an associated telephone to ring. A typical signaling scheme well established in the market between the CO class 5 switches and the PSTN is the GR-303 set of requirements established by Telcordia Technologies, Inc. GR-303 defines (for example for the Loop Start signaling type) specific state changes: loop open and loop closure on the CPE side; loop current feed open, loop current feed and ringing on the CO side. These states, triggered by specific events, are then mapped into specific signaling messages (for example using ABCD bits) which then get notified to the peer end, which reacts accordingly.
[0027] Unfortunately, the above disclosed signaling scheme does not work in back-to-back (i.e., direct CPE to CPE) scenarios because the functionality required to facilitate the communication is not present at the CPE side. In particular, in conventional systems, signaling messages are not symmetrical. That is, information is not passed back and forth between the caller and the callee. Rather, at least one intermediary CO is necessary to decipher and route the transmitted information. Further, tones, such as the dial tone, the engaged tone and the error tone, are traditionally generated by the CO in-band (and specifically, by the class 5 switch associated with the CO), rather than directly by the individual CPE devices involved in the call. Also, conventional CPE devices are provided with limited intelligence. In addition, dialed digits received during the call are conventionally not decoded by the CPE software affiliated with the receiving party. Rather, the CO performs the decoding functions and relays necessary information to the receiving CPE if recognized.
[0028] These problems can be overcome adopting the symmetrical signaling scheme of the present invention. As stated above, in circumstances where CO involvement is either unnecessary, unavailable, or overly expensive, it may be desirable to establish a communication directly between two (or more) CPE devices directly. Returning to FIG. 1, the inventive symmetrical signaling scheme removes the CO 106 from the information pathway between CPE 102 and CPE 104 . In particular, as will be described in additional detail below, tones, such as the dial tone, are generated locally according to related state transitions, and an extended state machine is adopted. Further, dialed digits are transported between the CPE devices 102 and 104 using ITU-T I.366.2 dialed digits secondary service packets, simplifying the need in the digital signal processor to recognize tones (tone detection), and entirely delegating the host processor to handle the required state machine.
[0029] In one embodiment, the inventive symmetrical telephony signaling scheme is based on the following S signaling messages: TALK, TEARDOWN, RINGING, BUSY, and ERROR. In addition, the state machine implemented at each connected CPE device is composed of one of the following six states: ONHOOK; OFFHOOK; DIALTONE; RINGBACK; RINGING; and TALKING. The transition from one state to another is then triggered by receiving signaling messages from the connected CPE device, or triggered by local events at the individual CPE device, such as going ‘onhook’ or ‘offhook’ at the device itself.
[0030] Turning now to FIG. 3, there is shown a block diagram illustrating the transitions between the various states described above. The illustrated transitions are triggered by local events (solid arrows) or signaling messages (dotted arrows). Signaling messages are transported using channel associated signaling (CAS) secondary service packets as generally defined in ITU-T I.366.2. However, in accordance with the present invention, the size of the transmitted CAS packets is increased from the standard 5 bytes to 8 bytes (3 additional bytes) in order to carry additional information required by the new signaling scheme. Further, dialed digit packets received in-band have also been extended in size from the conventional 6 bytes to 9 bytes in order to carry the additional information required. The additional information required include values relating to the channel ID in use and the connection ID of the call originator. The channel ID of the originator determines which channel ID will be used in establishing the channel. So the call originator acts as a master, in this respect. Additionally, the connection ID is needed when the peer end (callee) posts some messages (i.e. when it's gone ONHOOK) back to caller for some event notification.
[0031] Relating now to the particular information contained within each of the CAS signaling packets, the initial 5 bytes contain information identical to that contained within traditional CAS packets formed in accordance with the ITU-T I.366.2 functional specification. However, in accordance with the present invention, the extra 3 bytes referenced above contain different information according to what kind of event they are triggered. In the conventional manner, bytes 1 - 5 contained the following information: byte 1 : redundancy[ 8 - 7 ] timestamp[ 6 - 1 ]; byte 2 : timestamp[ 8 - 1 ]; byte 3 : reserved[ 8 - 5 ],A bit[ 4 ],B bit[ 3 ],C bit[ 2 ],D bit[ 1 ]; byte 4 : message type[ 8 - 3 ],crc10[ 2 - 1 ]; byte 5 : crc10[ 8 - 1 ].
[0032] After the standard first 5 bytes definitions, the content of bytes 6 - 8 are defined by the events which result in the packet generation and transmission. The following include examples of CAS packet formation for several specific events. In particular, where the event is either a CPE telephone transition from the TALKING state to the ONHOOK state or from a RINGBACK state to an ONHOOK state, byte 6 of the CAS packet includes a peer CPE ID value; byte 7 includes a value representative of the AAL2 CPS CID (channel ID) currently in use; and byte 8 is unused.
[0033] For dialed digit packets, the six bytes are again identical to conventional ITU-T I.366.2 packets, with byte 1 relating to redundancy[ 8 - 7 ] and timestamp[ 6 - 1 ]; byte 2 relating to timestamp[ 8 - 1 ]; byte 3 relating to reserved[ 8 - 6 ] and signal level[ 5 - 1 ]; byte 4 relating to digit type[ 8 - 6 ] and digit code[ 5 - 1 ]; byte S relating to message type[ 8 - 3 ], and crc10[ 2 - 1 ]; and byte 6 relating to crc10[ 8 - 1 ]. However, as referenced above, additional bytes 7 - 9 are configured to include additional information relating channel and connection ID values. In particular, byte 7 relates specifically to the CPE id of the “sender”; byte 8 relates to the AAL2 CPS CID (channel ID) to be used; and byte 9 is unused (set to 0) and is only required as a packet size discriminator. By providing this additional information in the CAS signaling message packets and the dialed digit packets, peer CPE devices are able to responde to received signals in an appropriate manner.
[0034] Referring now to FIG. 4, there is shown a flow chart describing a method for setting up a voice call utilizing the signaling scheme of the present invention. For description purposes, the system used in performing the described method should be understood to include two CPE devices, each having 3 telephones/handsets already connected and initialized. On each board, the first telephone has a connection ID 0 and channel ID 16 , the second telephone has a connection ID 1 and channel ID 17 and the third telephone has a connection ID 2 and channel ID 18 . To further simplify the description, it should be understood that Px.y is shorthand for board X, telephone Y (i.e., P 1 . 2 means telephone 2 of board 1 ).
[0035] In step 400 , P 1 . 1 goes offhook and goes into DIALTONE state, wherein the dial tone is locally generated by the CPE device. In step 402 , P 1 . 1 dials the number belonging to P 2 . 1 , and the dial tone is stopped, wherein each dialed number is transmitted to the peer end as a dialed digit packet. In step 404 , the peer end assesses that P 2 . 1 is in an ONHOOK state, so accordingly, in step 406 , sets P 2 . 1 into a RINGING state and makes it ringing. In step 408 , the peer end sets the correct channel parameters (i.e. which channel ID to use), then transmits a CAS packet including a RINGING message back to P 1 . 1 . Upon reception of the RINGING message, P 1 . 1 goes into a RINGBACK state in step 410 and, in step 412 , a ring back tone is locally generated. When P 2 . 1 is answered, it goes off hook, and because it was in a RINGING state, its state changes into a TALKING state in step 414 . At this point a CAS packet with a TALK message is transmitted to P 1 . 1 in step 416 . In response, P 1 . 1 likewise enters a TALKING state. Due to the symmetrical nature of the inventive signaling system, no CO device is required to enable the transmission of information between P 1 . 1 and P 2 . 1 .
[0036] Referring now to FIG. 5, there is shown a flow chart describing a method for tearing down a voice call utilizing the signaling scheme of the present invention. In step 500 , it is assumed that P 1 . 1 and P 2 . 1 are connected to each other and voice traffic is exchanged between them. In step 502 , P 1 . 1 goes on hook and terminates the voice call. Accordingly, P 1 . 1 changes into an ONHOOK state in step 504 . In response, P 1 . 1 transmits a CAS packet including a TEARDOWN message to P 2 . 1 in step 506 . Upon reception of the TEARDOWN message, P 2 . 1 goes into a DIALTONE state in step 508 , and a dial tone is locally generated. At this stage, P 2 . 1 may choose to go on hook, with the state changing into an ONHOOK state in step 510 , or it can dial a new number in step 512 .
[0037] In summary, the proposed telephony signaling protocol is characterized by complete symmetry and simplicity based on a simple state machine and message set; flexibility, because it does not impose limits in terms of how many handsets can be supported; and robustness, exploiting triple redundancy and packet refresh features of I.366.2, and reducing the likelihood of messages getting lost or discarded.
[0038] While the foregoing description includes many details and specificities, it is to be understood that these have been included for purposes of explanation only, and are not to be interpreted as limitations of the present invention. Many modifications to the embodiments described above can be made without departing from the spirit and scope of the invention, as is intended to be encompassed by the following claims and their legal equivalents. | A system and method for providing symmetrical connectivity between at least two consumer premises equipment (CPE) telecommunications devices is provided. At least two consumer premises equipment telecommunications devices are operatively connected over an asynchronous transfer mode telecommunications network. The at least two consumer premises equipment telecommunications devices are configured to perform local tone generation, local tone detection and decoding, and direct transfer and decoding of dialed digits using channel associated signaling secondary service packets and dialed digit packets to transition between various states. By providing symmetrical connectivity of CPE devices, central office involvement may be eliminated. | 7 |
Several variations of continuously variable transmissions are known. With respect to belt transmission should be systems belt, preferably a push belt or a V belt or a chain, preferably a tension chain, is arranged between a drive end connected to the vehicle and an output end connected to the wheels of the vehicle. The drive end and the output end each generally have an axially displaceable V-pulley. Such systems are described, for example, in European Published Patent Application No. 451,887 and German Published Patent Application No. 44 11 628. The efficiency of such a transmission depends to a significant extent on the dimensioning of the force of the pulleys acting against the belt element so that slippage between the pulleys and the belt element is reliably prevented. This force can be dimensioned with a certain safety margin based on the largest torque to be transmitted. However, during a normal operation of the vehicle, i.e., at lower transmission torques, this generates excessively high friction forces and hydraulic losses in the gear.
One possibility of improving this situation is to adapt this force to the instantaneous transmission torque. Therefore, in European Published Patent Application No. 451,887, this force is controlled as a function of engine torque. Another possibility is to reduce this force to a level that is just sufficient to reliably prevent slipping at the prevailing transmission torque. Drive slip control is described, for example, in the German Published Patent Application No. 44 11 628. The most accurate possible knowledge of the instantaneous slip is required for such a drive slip control. It is therefore proposed in German Published Patent Application No. 44 11 628 that the speed of the belt element be detected.
ADVANTAGES OF THE INVENTION
An object of the present invention is to detect a slip in a simple accurate manner. As mentioned above, the present invention relates to a belt transmission with an adjustable transmission ratio, having a drive end and an output end. The belt means establishes an operative mechanical connection between the drive end and the output end, with the slip behavior of the connection being subject to influence, an influencing means is provided to influence the slip of the belt means.
In the present invention at least two sensor units are provided and are arranged in the area of the belt means, between the drive end and the output end. The signals of these sensor units are then sent according to the present invention to the influencing means for influencing the slip of the belt means. Due to the sensor units arranged according to the present invention, it is possible to easily determine the actual slip to a high degree of accuracy and to use it to influence the slip.
It is especially advantageous to arrange the sensor units in such a way that the sensor units detect changes in relative position between the belt means and the sensor units.
It is also advantageous that the belt means are subdivided into individual segments which move past the sensor units for establishing the operative mechanical connection between the drive end and the output end. The sensor units are then arranged so that their signals represent the segments moving past the sensor units.
As mentioned previously, the drive end and/or the output end have at least one axially displaceable element having essentially the form of a V-pulley. As the belt means, at least one belt, preferably a push belt, or a belt or chain may be stretched between pulleys representing the drive end and the output end, where the slip between the belt means and the pair of pulleys around which the belt means are wrapped can be influenced.
It is especially advantageous if one of the sensor units is arranged so that its signals represent the segments moving toward the drive end or the output end, while the other sensor units are arranged so that their signals represent the segments moving away from the drive end or output end.
The influencing means are advantageously designed so that a geometric transmission ratio is formed, depending on the difference between the two sensor signals. To determine the actual slip, first and second rpm sensing means can be provided to detect the rpm of the drive end and/or output end, where the output signals of these rpm sensing means can be sent to the influencing means. The influencing means are designed in such a way that an rpm transmission ratio is determined as a function of the output signals of these rpm sensing means. The actual slip of the belt means is determined by comparison of the geometric transmission ratio and the rpm transmission ratio.
The influencing means may be designed so that the slip is regulated to a predetermined value, with the actual slip being compared with a predetermined setpoint to control the slip.
The present invention also relates to a method of operating a belt transmission with an adjustable transmission ratio, with a drive end and an output end, as well as with a belt means for establishing an operative mechanical connection between the drive end and the output end to influence the slip behavior of this connection. Further in the present invention the parts of the belt means moving toward the drive end or the output end and the parts of the belt means moving away from the drive end or the output end are sensed, and the slip of the belt means is influenced according to the parts thus sensed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a schematic block diagram with a schematic drawing of a belt transmission according to the present invention.
FIG. 2 shows an arrangement of sensor units according to the present invention.
FIG. 3 shows a flow chart according to a method of the present invention.
FIG. 4 shows a block diagram for measuring a belt slip according to the present invention.
FIG. 5a shows a conventional push belt.
FIG. 5b shows a belt element of the push belt of FIG. 5a.
FIG. 5c shows a belt element according to an embodiment of the present invention.
DETAILED DESCRIPTION
FIG. 1 shows a sectional view of a belt transmission. Engine torque M m delivered by internal combustion engine 1 can be influenced by throttle valve 2. Throttle valve 2 is mechanically or electrically connected to the gas pedal (not shown). Internal combustion engine 1 is usually linked to the drive end (primary side) of CVT 4, usually by means of a clutch and/or a converter 3. The output end (secondary side) of CVT 4 is connected to the wheels of the vehicle via a downstream gear (not shown). The CVT has an axially displaceable V-pulley 5 and 6 on the primary and secondary sides, respectively. To adjust the transmission ratio, a suitable primary pressure P p and secondary pressure P s are built up in oil chambers 7 and 8, respectively. A suitable choice of primary pressure P p and secondary pressure P s as manipulated variables must be made to guarantee that
1. transmission ratio u corresponds to the desired ratio of primary rpm N p and secondary rpm N s , and
2. force-transmitting push belt 9 (or chain or V belt) is pressed strongly enough against the pulleys to prevent push belt 9 from slipping.
Above-mentioned point 1 is implemented by an electrohydraulic transmission or primary rpm control 10. A belt tension control 11 is used for point 2.
In the master-slave principle which is illustrated in FIG. 1 and is used frequently, secondary pressure P s serves to adjust the belt tension and primary pressure P p serves to adjust the transmission ratio or primary rpm. To regulate the belt tension, in addition to primary rpm N p and secondary rpm N s , the engine rpm N m (rpm sensor 12) and output signals N in and N out of sensor units S1 and S2 described below are sent to block 11. Depending on these signals, a secondary pressure P s to be established is determined. This is described in greater detail below with reference to FIGS. 3 and 4.
With the partner principle as a possible alternative, the belt tension control influences both the primary and secondary pressures.
As mentioned previously, the torque in such a CVT is transmitted with a belt element 9 between the two sets of pulleys shown in FIG. 1. The transmission ratio is varied by adjusting the active radii of the pulleys. The pulley sets are each composed of two truncated cones or V-pulleys which can be shifted with respect to one another. This is shown in the schematic diagram in FIG. 2. Which shows a sectional view perpendicular to the axes of the truncated cones or V-pulleys, with arrow 2 indicating the direction of rotation in the normal forward operation of the vehicle. Belt element 9 is indicated with dash-dot lines in two extreme gear positions u min and u max . The primary side on the engine end is labeled as "Prim" and the side facing the wheels is labeled as "Sek."
The active radii for the belt element, which is a push belt 9 in the present example, change due to the displacement of the V-pulleys toward one another. The radius at which belt element 9 acts on the primary side Prim., i.e., the radius at which the force is transmitted, is r p while that on the secondary side Sek is r s . These radii can be determined as theoretical quantities even if belt 9 does not run ideally on the circle segments thus determined. Length L r of belt 9 can be assumed as constant. The assumption that the path of belt element 9 is composed of two segments of a circle and two straight line segments (see FIG. 2) is correct in wide ranges of operation and can always be assumed without any great error.
As shown in FIG. 2, the axes of the pulleys have a fixed spacing a. For the idea according to the present invention, one sensor unit each S1, S2 is arranged in the middle between the two pulleys, i.e., at a/2. These sensors S1, S2 are designed to be able to count individual segments 502 or marks on the belt element. The segments or marks are applied to belt element 9 with exactly constant spacings. This will be described in more detail with reference to FIGS. 5a, 5b and 5c.
The idea according to the present invention is based on the fact that length L p of belt element 9 between sensors S1 and S2 on primary side Prim. (and naturally also on secondary side Sek.) is a direct measure of the geometric transmission ratio u geo (=r s /r p ). This is to be illustrated on the basis of the following analysis of the geometric relationships of the belt transmission.
Length L r of push belt 9 is obtained as follows:
equation 1: ##EQU1##
The geometric transmission ratio u geo is defined as follows: ##EQU2## where r s denotes the instantaneously operative secondary radius and r p is the instantaneously operative primary radius. Angle α between the push belt and the line connecting the axes is (axis spacing a):
equation 3: ##EQU3##
Length L p of belt 9 between the measurement points of sensor units S1 and S2 is obtained as follows:
L.sub.p =L.sub.up +2*L.sub.ap (4),
where L up denotes the wrap length of the primary pulley and L ap is the path between the point of contact on the primary pulley and sensor units S1 and S2.
This yields the following results for the wrap length L up of the primary pulley and for the path L ap between the point of contact on the primary pulley and sensor units S1 and S2: ##EQU4##
Thus, length L p of the push belt between sensor units S1 and S2 is a function which depends only on primary radius r p : ##EQU5##
For a known transmission, r p is a function of the geometric transmission ratio u geo =u, which depends only on the transmission parameter L r (length of the belt) and a (distance between pulley axes). ##EQU6##
When equation 8 is substituted into equation 7c, this leads to an equation for determining L p , which depends only on the geometric transmission ratio u geo =u and fixed transmission parameters. If this equation is plotted in a curve, the geometric transmission ratio u geo can be determined from length L p of belt element 9 stored on the primary side.
If the system operates without any noticeable slip between the belt and pulleys, the geometric transmission ratio u geo must be equal to the rpm transmission ratio u N =N p /N s , where N p and N s denote the rpm on the primary side and the secondary side, respectively (sensors 13, 14). If these two transmission ratios are not the same, the system operates with a certain belt slippage.
A concrete embodiment is described below with reference to FIGS. 3 and 4.
As shown in FIG. 4, the rpm transmission ratio u N =N p /N s is determined first in block 111 of slip regulator block 11 (influencing means). Block 112 to receives output signals N in and N out of sensors S1 and S2. As mentioned previously, these sensors S1 and S2 are designed to count individual segments 502 or marks on the belt element. The segments or marks are applied to belt element 9 with exactly constant spacings. If the transmission has the direction of rotation indicated by arrow 2 in FIG. 2, sensor unit S1 counts the belt segments N in or belt marks arriving on the primary side, and sensor unit S2 counts the belt segments N out or belt marks moving away from the primary side.
According to FIG. 3, which shows how block 112 (FIG. 4) functions, the current rpm transmission ratio u N is entered in step 302 after starting step 301.
In the respective end positions (at the smallest and largest transmission ratios), the number of segments or marks on the primary side and on the secondary side is known. If these operating states prevail (at the smallest transmission ratio u min and at the largest transmission ratio u max ), the measurement can be simply started. For this reason, an inquiry is performed in step 303 to determine if the operating state is currently u min or u max . However, the operating state of minimum or maximum transmission ratio can also be determined through other parameters, e.g., by input of the primary pressure and/or the secondary pressure.
Such an operating state must be achieved at least once at the beginning of the measurement. If a maximum or minimum transmission ratio is found as the operating state in step 303, then starting value L min or L max is set in step 304 as starting value L start for length L p of belt 9 on the primary side between the measurement points of sensor units S1 and S2.
Output signals N in and N out of sensors S1 and S2 which indicate the segments entering and leaving on the primary side are entered in step 305. In step 306, the actual length L p of belt 9 is determined on the primary side between the measurement points of sensor units S1 and S2 so that the number of incoming segments is added to starting value L start and the number of outgoing segments is subtracted from said starting value.
Then in step 307 the geometric transmission ratio u geo is determined from value L p obtained from the curve derived above (equations 7c and 8).
If it is found after a first start run in step 303 that an extreme transmission ratio u min or u max has not been set, then in step 308 output signals N in and N out of sensors S1 and S2 are entered; these signals indicate the segments entering and exiting, respectively, on the primary side. In step 309, the actual length L p of belt 9 is determined on the primary side between the measurement points of sensor units S1 and S2 in such a way that the number of incoming segments is added to the value L p determined previously, and the number of outgoing segments is subtracted from the value L p . The geometric transmission ratio is determined in block 307 described above.
An actual value λ B ,ist for belt slip λ B is calculated from the actual rpm transmission ratio u N determined in blocks 111 and 112 in FIG. 4 and the actual geometric transmission ratio u geo (for example, by forming the difference). This value λ B ,ist is then compared with a corresponding setpoint λ B ,soll in block 114, whereupon the belt tension is adjusted (for example, by adjusting secondary pressure P s in the master-slave principle mentioned above) depending on this comparison so that there is no slip (controller R, block 1142).
Setpoint λ B ,soll for the belt slip is determined, as mentioned above, by taking into account engine torque and engine rpm.
FIGS. 5a, 5b, and 5c show embodiments of belt segments or belt marks.
A push belt is known to comprise a number of segments 502 held together by an elastic steel ring 503. FIG. 5a shows a conventional push belt 9 with individual segments 502, and FIG. 5b shows an individual segment 502 (not including the part shown with dotted lines).
As shown in FIG. 5a, it is not necessary with conventional push belts to apply marks that can be analyzed because the segments themselves can be counted even on the basis of gaps 501 detected by suitable known magnetic sensors S1 and S2. In addition, the use of known eddy current sensors is also possible in particular.
Another possibility for even more distinct detection of segments 502 is shown in FIG. 5c, where every second segment 502 has been lengthened by a few millimeters on the outside A of the belt (see also the dotted-line portion of segment 502 in FIG. 5b). Such a mark is even simpler to detect than the gaps on the inside of the conventional belt shown in FIG. 5a. In the embodiment shown in FIG. 5c, sensor units S1 and S2 must of course be arranged on the outside of the belt. | A belt transmission having an adjustable transmission ratio and a drive end and an output end. The belt of the belt transmission establishes an operative mechanical connection where the slip can be influenced between the drive end and the output end, where an influencing device influences the slip of the belt means. At least two sensor units are provided and are arranged in the area of the belt and between the drive end and an output end. The signals of these sensor units are then sent to the influencing device to influence the slip of the belt. With the sensor units arranged in this manner, it is possible in a simple manner to detect the actual slip with a high accuracy and to use this to influence the slip. | 5 |
This is a continuation patent application based upon application Ser. No. 10/791,128 filed Mar. 2, 2004, now U.S. Pat. No. 7,369,656 which was a regular patent application based upon and claiming the benefit of provisional patent application Ser. No. 60/534,206, filed Jan. 5, 2004.
The present invention relates to a clip mount for a cellular telephone attachment system with a button mount and a method therefor.
BACKGROUND OF THE INVENTION
Many cell phone users utilize a clip mount which may be attached to his or her belt, purse or other strap. These clip mount systems coact with a clip-on structure which is removably attached to the generally rectangular body of the cellular telephone. The sub-system attachment to the cellular telephone includes a button which protrudes from the backside of the sub-system.
The present invention is a clip mount for this type of button mount.
OBJECTS OF THE INVENTION
It is an object of the present invention to provide a clip mount for a cellular telephone attachment system with a button mount.
It is another object of the present invention to provide a two piece clip mount with a movable actuator that flexes a resilient locking tongue thereby releasing the button from the locking cavity in the clip mount body.
It is a further object of the present invention to utilize first and second cam surfaces which coact together to flex the resilient locking tongue from a locking position to a button release or unlock position.
It is another object of the present invention to provide a movable actuator which, in a rest position, biases the resilient locking tongue into a locking position and, in a release position, biases the locking tongue into an unlock position.
SUMMARY OF THE INVENTION
The clip mount operates with a cellular button mount. The clip mount includes a body defining a complementary locking cavity for the button and a resilient locking tongue disposed in the locking cavity. The tongue is adapted to bias the button into a locking position in the locking cavity. The tongue includes at least one cam surface. A movable cam actuator, movably mounted on the body, includes another cam surface which coacts with the first cam surface permitting the resilient locking tongue to flex from a locking position to an unlocking position. An enhancement includes one cam and cam follower to flex the tongue from the locking the unlocking position and a second cam and cam follower to flex the tongue to the locking position. The method of mounting includes biasing the button to a locking position in the locking cavity, providing a sloped cam surface on the resilient locking tongue and moving a second cam surface over the locking tongue cam surface thereby flexing the tongue from a locked to a button release position. Another embodiment of the invention includes a tongue with two cam surfaces, one facing outboard and a second facing inboard. The cam actuator has two actuator surfaces, one coacting with the tongue's outboard surface and the other coacting with the tongue's inboard facing surface. When the actuator is at rest (biased upward), the tongue is biased outward (laterally outward from the locking cavity) by one cam surface (to achieve a locking cam action) and when the actuator is depressed downward, the tongue moves laterally inward due to the other cam surface (to achieve an unlocking cam action). Alternatively, the locking cam system (with the actuator at rest in an upward position) can be used separate from the unlocking cam system.
BRIEF DESCRIPTION OF THE DRAWINGS
Further objects and advantages of the present invention can be found in the detailed description of the preferred embodiments when taken in conjunction with the accompanying drawings in which:
FIG. 1 diagrammatically illustrates one embodiment of the clip mount showing the actuator member removed from the clip body;
FIG. 2 diagrammatically illustrates another embodiment of the present invention and particularly shows the button mount (the cellular telephone and attachment sub-structure is not shown affixed to the button mount), actuator and clip body;
FIG. 3 is a front elevational view of the clip mount primarily illustrating the resilient locking tongue and the first cam surfaces;
FIG. 4 diagrammatically illustrates a cross-sectional view primarily showing the slope of the first cam surface on the locking tongue;
FIG. 5 diagrammatically illustrates the first embodiment of the invention with a resilient nub to angularly position the phone with respect to the clip mount;
FIG. 6 diagrammatically illustrates the button mount used with the embodiment of the invention shown in FIG. 5 ; and
FIG. 7 shows the actuator member with a lower cam actuator surface (for the button release) and shows an upper cam actuator surface that, when the actuator is upwardly biased (a rest position), the upper cam actuator surface acts on an upper tab laterally extending from the tongue ( FIG. 8 ) to bias the tongue laterally outward.
FIG. 8 shows the actuator in the clip-mount body and the laterally extending tabs affected by the upper cam actuator surfaces. When the actuator is depressed down, the lower surface moves the tongue inwards thereby releasing the button from the lip lock—when the actuator is biased upward (see spring in FIG. 2 ), the actuator biases the tongue laterally outward thereby creating additional locking force or bias on the button 43 ( FIG. 2 ).
FIG. 9 diagrammatically illustrates a detail, cut-away view of the tongue with the lock cam surfaces and unlock cam surfaces.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention relates to a clip mount for a cellular telephone attachment system having a button mount and a method of mounting.
FIG. 1 shows clip mount 10 including a belt loop 12 having a belt loop cavity 14 therein. Similar numerals designate similar items throughout all the figures. Belt loop 12 , as shown in FIG. 2 , has a free end 15 that permits the user to slip a strap or a belt as shown by arrow 16 into belt or strap cavity 14 .
Although the figures show a specific manufactured embodiment for the clip mount, other structures may utilize the key portions of the present invention clip mount 10 includes three (3) basic elements which are clip body 20 , defining a locking cavity 22 , a resilient tongue 24 , an actuator 26 , and some cam surfaces. Actuator cam surfaces are located on actuator 26 and one of those cam surfaces is numerically identified as cam surface 28 . Resilient tongue 24 moves or flexes as shown by double headed arrow 30 based upon the position of actuator cam surface 28 and another cam surface complementary thereto. In FIG. 1 , a corresponding tongue cam surface 32 is illustrated. FIG. 3 shows resilient locking tongue cam surfaces 31 and 32 and actuator cam surface 28 ( FIG. 1 ) rides along and atop resilient locking tongue cam surface 31 . When the actuator cam surfaces 28 , 29 ( FIG. 2 ) ride atop the locking tongue cam surfaces 32 , 31 ( FIG. 3 ), resilient tongue 24 flexes from a locking position to a button release or unlocking position (laterally inboard flexation) thereby freeing the button from the clip mount 10 .
It should be noted that other mechanical structures could accomplish the same features described herein and FIGS. 1-6 show one working embodiment. For example, although actuator 26 is shown as substantially U-shaped with two legs and two cam surfaces, a single movable member with a user actuatable surface and a single cam could operate to move resilient locking tongue 24 from a button locking position to an unlocking position.
Clip body 20 includes a channel cavity 40 into which is movably disposed actuator member 26 . A resilient locking tongue 24 is mounted within cavity 40 . Locking tongue 24 is adopted to flex or move as shown by double headed arrow 30 in FIG. 21 . When a button, such as button 41 in FIG. 2 , is placed within locking cavity 22 , the button coacts with semi-circular rim member which, in FIG. 1 , consists of rim member 42 and rim member 44 . Essentially, button 41 includes a peripheral plate 43 and a stem 45 . Peripheral plate 43 locks beneath rim elements 43 , 44 and resilient tongue 24 includes a terminal edge 46 that coacts with either stem 45 or peripheral plate 43 to securely lock button 41 in locking cavity 22 . In general to release button 41 from locking cavity 22 , resilient tongue 30 must be flexed generally inboard into channel cavity 40 such that the tongue no longer coacts with stem 45 or plate 43 thereby permitting the removal of button 41 and any attached cell phones or cell phone structure.
Actuator member 26 includes user actuation surface 50 . Actuator member 26 is generally U-shaped consisting of a base 27 and legs 52 , 53 . The terminal ends 54 , 55 of legs 52 , 53 define stops. A resilient member, such as springs 56 , 57 coact with stop 54 , 55 to bias actuation member 26 in a direction shown by arrow 60 , that is, in a direction such that resilient locking tongue 24 is in a locking position with respect to button 41 . The user depresses surface 50 , the actuator moves downward ( FIG. 3 ), the cam surfaces engage and push the tongue laterally inward. Upon removal of the depressing force on surface 50 , springs or resilient elements 56 , 57 force the actuator back to the original position.
FIG. 2 shows that actuator 26 is positioned in channel cavity 40 and button 41 fits in locking cavity 22 .
In FIG. 1 , legs 52 , 54 are movably mounted in leg channels 64 , 66 . Further, once actuator member 26 is disposed in channel cavity 40 , actuator member 26 cannot be removed because stop 70 locks within and also moves within side cutout 72 . Removal of actuator 26 is prohibited because stop 70 cannot pass edge 74 defining one end of side cutout 72 .
FIG. 2 diagrammatically illustrates clip mount 10 in a slightly different embodiment. Rather have two rim segments 42 , 44 as shown in FIG. 1 , a substantially semi-circular rim 43 defines one side of locking cavity 22 . Edge 46 of resilient locking tongue 24 captures the opposite end of button 41 . Button 41 is shown as being insertable into locking cavity 22 and actuator 26 is shown as being insertable into channel cavity 40 (not identified in FIG. 2 ).
FIG. 3 diagrammatically illustrates clip mount 10 and shows cam surfaces 31 , 32 on resilient locking tongue 24 . Semi circular rim 43 is also shown in FIG. 3 . Arrow 80 shows the direction in which actuator 26 is inserted. Actuator 26 moves up and down in the channel cavity 40 after insertion. It should be noted that actuator 26 is utilized in conjunction with the split rim embodiment shown in FIG. 1 and in the single, substantially semi-circular rim embodiment shown in FIG. 2 .
FIG. 4 diagrammatically shows a substantially cross-sectional view of clip 10 . Particularly, resilient tongue cam surface 31 is shown as either an inclined slope or a gentle curved slope. Since actuator member 26 is inserted in the direction shown by arrow 80 , and since cam surfaces 28 , 29 ( FIG. 2 ) operate on cam surfaces 32 , 31 , the depression of actuator 26 causes tongue cam surfaces 32 , 31 to move laterally inboard in the direction of arrow 82 in FIG. 4 thereby causing inboard flexation of resilient locking tongue 24 . This inboard movement of tongue 24 causes terminal locking surface 46 ( FIG. 2 ) of tongue 24 to disengage button 41 thereby releasing button 41 and any associated structure attached to button 41 from clip mount 10 .
FIG. 5 diagrammatically illustrates clip mount 10 in the embodiment shown in FIG. 1 . Particularly, rim segments 42 , 44 are separated by a resiliently mounted knob 90 . Particularly, knob 90 is mounted on a bar 92 spanning left and right sides of clip body 20 . Bar 90 flexes and is resilient.
FIG. 6 diagrammatically shows button 101 having a top plate 102 and a stem 104 . Stem 104 includes a plurality of notches or cutouts, one of which is cutout 106 . Button 101 fits within locking cavity 22 . When the cell phone structure attached to button 101 is rotated as shown by arrow 110 in FIG. 6 , knob 90 may snap into or lock into notch 106 of button 101 . In this manner, the cell phone or clip on element for the cell phone can be rotated clockwise or counterclockwise about face 130 of clip body 20 . Button 41 shown in FIG. 2 does not have notches and rim 43 in FIG. 3 is not split and does not have a resilient knob. However, button 101 may work in conjunction with unitary rim 43 . Similarly, button 41 may work in conjunction with split rim 42 , 44 provided that knob 90 does not impede the button locking ability of button 41 . In this manner, the buttons are inter-changeable but additional functionality is noted with button 101 and resilient knob 90 in FIG. 5 .
FIGS. 1-5 diagrammatically illustrate a clip mount wherein, upon depression of actuator member 26 , cam actuator surfaces 28 , 29 coact with cam follower surfaces 32 , 31 ( FIG. 3 ) such that tongue 24 flexes or moves laterally inboard (direction 82 , FIG. 4 ) thereby releasing the button from locking cavity 22 .
In FIGS. 7 and 8 , actuator 26 includes locking cam surfaces and unlocking cam surfaces. Unlocking cams are represented by cam actuator surfaces, one of which is surface 28 , which is sometimes identified herein as the first cam actuator surface. Locking cams are provided on actuator 26 as cam actuator surfaces 152 , 154 in FIGS. 7 and 8 . Actuator surfaces 152 , 154 coact with second cam follower surfaces 162 , 164 which are, in the illustrated embodiment, found on laterally extending tabs protruding from tongue 24 . An alternative embodiments, the cam follower surfaces 162 , 164 may be formed on the tongue body 24 itself rather than on extending tabs.
FIG. 8 shows actuator 56 in a rest or a button locking position. Further, FIG. 8 shows actuator 26 in a upright or raised position. In this locking or raised position, second cam actuator surfaces 152 , 154 bias locking tongue 24 upward (laterally outward from the cavity) thereby providing additional locking force for the button mount adapted to be disposed in locking cavity 24 . When actuator 26 is moved downward as shown by arrow 170 in FIG. 8 , the locking cam systems 162 - 152 , 164 - 154 release and the unlocking cams 29 , 31 and 28 , 32 operate to laterally depress tongue 24 (in a direction 82 shown in FIG. 4 ) thereby releasing the button mount from locking cavity 22 .
FIG. 8 shows the upper and lower cams, the lower cams 29 - 31 , 28 - 32 are explained in connection with FIG. 2 and the upper cams 162 - 152 , 164 - 154 cooperate to move the tongue outward when the actuator member is at rest the common biased position.
FIG. 9 shows a detail, cut-away view of the tongue 24 , extending into locking cavity 22 . The tongue 24 has, extending transversely from its longitudinal axis, a pair of locking cam follower surfaces 154 , 152 and a pair of unlocking cam follower surfaces 32 , 31 . These follower surfaces track the cam surfaces on the movable actuator. When the actuator (not shown in FIG. 9 ) is at rest in its biased upward position, the locking cams 154 , 152 bias tongue 24 laterally outward from locking cavity 22 thereby additionally locking the button (not shown) in the locking cavity 22 . When the actuator is depressed downward, the locking cams release and the unlocking cam system is activated (see cam followers 32 , 31 ) thereby moving tongue 24 laterally inward towards cavity 22 . This releases the button from the locking cavity.
It should be noted that the locking cam-cam follower system may be employed separate from the unlocking cam-cam follower system. It should also be noted that the cam and cam followers may be deployed at different locations and on different components than shown in the preferred embodiment.
The claims appended hereto are meant to cover modifications and changes within the scope and spirit of the present invention. | The clip-mount operates with a button mount and includes a body defining a locking cavity for the button and a resilient locking tongue therein. The tongue biases the button into a locking position. The tongue includes at least one cam surface. A movable cam actuator on the body includes another cam surface which coacts with the first cam permitting the tongue to flex from a locking to an unlocking position. An enhancement includes one cam and cam follower, to flex the tongue from the locking to the unlocking position, and a second cam and cam follower to flex the tongue to a button locking position. The method includes biasing the button to a locking position, providing a sloped cam surface on the resilient locking tongue and moving a second cam surface over the tongue cam surface thereby flexing the tongue from a locked to a button release position. | 7 |
TECHNICAL FIELD
[0001] The present invention relates to a crystal form of (R)-praziquantel, the preparation method thereof, and applications thereof in the drugs treating parasitic diseases. In addition, the present invention also relates to a product that prepared by taking the crystal form of (R)-praziquantel as an active component, which includes, but not limited to, an active pharmaceutical ingredient, a formulation, a premix, a healthcare product and the like.
BACKGROUND
[0002] Praziquantel is a synthesized pyrazine isoquinoline derivative, also called cyclo-praziquantel, and a white or off-white crystalline powder and bitter in taste. It is worldwide recognized as a highly effective and broad-spectrum anti-parasite drug and widely used for treating diseases such as schistosomiasis japonica, schistosomiasis haematobium, schistosomiasis mansoni, clonorchiasis, paragonimiasis, sparganosis mansoni, fasciolopsis, echinococcosis, taeniasis, cysticercosis , etc. It has advantages such as broad anti-parasitic spectrum, high efficacy, low toxicity, short therapeutic course and easy to use, etc. In addition to human use, it is also widely used in anti-parasitic treatment of animals including poultry and livestock. The invention of praziquantel is a major breakthrough in the history of anti-parasitic chemotherapy. In the past 30 years, praziquantel has still been the first choice of drug for treating various parasitic diseases on the market.
[0003] Praziquantel is a racemic compound composed of (R)-praziquantel and (S)-praziquantel together. Scientists have separated and obtained both pure optic isomers of (R)-praziquantel and (S)-praziquantel from synthesized praziquantel, and found in preclinical studies and preliminary clinical trials that: (R)-praziquantel is the active parasiticidal component of praziquantel, while the (S)-praziquantel is inactive or even harmful; at the same dosage, the clinical efficacy of (R)-praziquantel is better than that of praziquantel, and (S)-praziquantel has little activity, bitter taste and is the major source of drug side effects; (R)-praziquantel shows lower cardiac toxicity than (S)-praziquantel. Therefore, the development of (R)-praziquantel has clinical application values of higher efficacy, less side effects, and better medical compliance.
[0004] Chinese invention patent publication number CN102786520A discloses a Form A of praziquantel and a preparation method and application thereof. The reported praziquantel Form A shows that the Height %=100 peak is at the position where 2-Theta=20.0±0.2° or d=4.4±0.2 Å and 43 diffraction peaks exist when analyzed by powder X-ray diffraction.
[0005] Chinese invention patent publication number CN102786519A discloses a state of matter of Form B praziquantel, wherein the Height %=100 peak is at the position where 2-Theta=18.7±0.2° or d=4.7±0.2 Å in powder X-ray diffraction analysis.
SUMMARY OF THE INVENTION
[0006] The present invention is intended to provide a crystal form of (R)-praziquantel and a preparation method thereof.
[0007] The present invention further provides an application of the crystal form of (R)-praziquantel and a drug composition containing the crystal form of (R)-praziquantel.
[0008] To achieve the above technical aims, the present invention employs the following technical schemes:
[0009] A crystal form of (R)-praziquantel, wherein the X-ray diffraction pattern (CuKα radiation) of the crystal format 25° C. shows the following seven diffraction peaks: 2-Theta=6.9±0.2°, 8.3±0.2°, 15.1±0.2°, 17.4±0.2°, 19.8±0.2°, 21.9±0.2°, 24.3±0.2° or d=12.74±0.20 Å, 10.61±0.20 Å, 5.87±0.20 Å, 5.09±0.20 Å, 4.48±0.20 Å, 4.06±0.20 Å, 3.66±0.20 Å.
[0010] Further, the X-ray diffraction pattern (CuKα radiation) of the crystal form at 25° C. further shows the following fifteen diffraction peaks: 2-Theta=13.4±0.2°, 14.1±0.2°, 15.7±0.2°, 16.6±0.2°, 17.9±0.2°, 18.2±0.2°, 19.0±0.2°, 20.6±0.2°, 23.8±0.2°, 27.4±0.2°, 28.5±0.2°, 29.0±0.2°, 30.9±0.2°, 33.7±0.2°, 39.5±0.2° or d=6.59±0.20 Å, 6.29±0.20 Å, 5.63±0.20 Å, 5.33±0.20 Å, 4.96±0.20 Å, 4.86±0.20 Å, 4.68±0.20 Å, 4.31±0.20 Å, 3.74±0.20 Å, 3.25±0.20 Å, 3.13±0.20 Å, 3.07±0.20 Å, 2.89±0.20 Å, 2.66±0.20 Å, 2.28±0.20 Å.
[0011] Further, the X-ray diffraction pattern (CuKα radiation) of the crystal format 25° C. further shows the following five diffraction peaks: 2-Theta=8.67±0.2°, 23.0±0.2°, 25.4±0.2°, 27.8±0.2°, 32.4±0.2° or d=10.19±0.20 Å, 3.86±0.20 Å, 3.50±0.20 Å, 3.20±0.20 Å, 2.76±0.20 Å.
[0012] According to one specific and preferred aspect, the X-ray diffraction pattern is shown in FIG. 1 .
[0013] Further, the X-ray diffraction pattern shows 36 diffraction peaks, and peak positions and peak intensities thereof are listed in Table 1, wherein, the peak positions vary within 0.2°.
[0014] Preferably, the thermogram of the crystal form measured by differential scanning calorimetry shows an absorption peak at the position of 111±3° C.; the melting point of the crystal form is 109±2° C. and the optical rotation of the crystal form [α] D ) at 20° C. is −140.12° (CH 3 OH).
[0015] According to the present invention, the infrared absorption spectrum of the crystal form shows absorption peaks at 3460 cm −1 , 3277 cm −1 , 3065 cm −1 , 3048 cm −1 , 3021 cm −1 , 3003 cm −1 , 2932 cm −1 , 2853 cm −1 , 2660 cm −1 , 1651 cm −1 , 1645 cm −1 , 1622 cm −1 , 1576 cm −1 , 1570 cm −1 , 1558 cm −1 , 1541 cm −1 , 1533 cm −1 , 1522 cm −1 , 1506 cm −1 , 1497 cm −1 , 1489 cm −1 , 1472 cm −1 , 1456 cm −1 , 1437 cm −1 , 1418 cm −1 , 1387 cm −1 , 1364 cm −1 , 1339 cm −1 , 1323 cm −1 , 1296 cm −1 , 1285 cm −1 , 1263 cm −1 , 1254 cm −1 , 1242 cm −1 , 1217 cm −1 , 1190 cm −1 , 1175 cm −1 , 1136 cm −1 , 1121 cm −1 , 1082 cm −1 , 1074 cm −1 , 1061 cm −1 , 1042 cm −1 , 1032 cm −1 , 997 cm −1 , 972 cm −1 , 962 cm −1 , 939 cm −1 , 924 cm −1 , 907 cm −1 , 893 cm −1 , 854 cm −1 , 831 cm −1 , 793 cm −1 , 756 cm −1 , 731 cm −1 , 723 cm −1 , 689 cm −1 , 648 cm −1 , 631 cm −1 , 594 cm −1 , 575 cm −1 , 546 cm −1 , 527 cm −1 , 509 cm −1 , 486 cm −1 , 473 cm −1 , 457 cm −1 , 442 cm −1 and 409 cm −1 , and the absorption peak positions vary within ±2 cm −1 . According to one specific aspect, the infrared absorption spectrum of the crystal form is shown in FIG. 5 .
[0016] Furthermore, the solubility of the crystal form of (R)-praziquantel in water and in simulated gastro-intestinal fluid at the temperature of 25° C. ranges from 0.30˜0.43 mg/mL.
[0017] Another technical scheme employed by the present invention is: the above preparation method of the crystal form of (R)-praziquantel which is obtained by using organic solvents to recrystallize (R)-praziquantel.
[0018] Further, (R)-praziquantel is added into the organic solvent and heated up to 20˜60° C. to dissolve (R)-praziquantel; the solution is filtered, and the filtrate is kept and cooled down to 10˜30° C. to crystallize, or added with an antisolvent, or the solvent is vacuum-removed to give a white solid, i.e. said crystal form of (R)-praziquantel.
[0019] The above mentioned organic solvent is selected from one or more of ethyl acetate, isopropyl acetate, methanol, ethanol, tetrahydrofuran and acetonitrile; the antisolvent is selected from one or more of water, toluene, n-heptane, cyclohexane and acetone.
[0020] According to one specific and preferred aspect of the present invention, the organic solvent is acetonitrile, and the antisolvent is acetone, toluene or a combination thereof. More preferably, the antisolvent is a combination of acetone and toluene, and the volume ratio of acetonitrile, acetone and toluene is 1:0.4˜0.6:3˜3.5.
[0021] Further, the method further includes the step of employing the following reaction to prepare (R)-praziquantel:
[0000]
[0022] the above step of preparing (R)-praziquantel specifically includes: reacting compound 4H with benzyl triethyl ammonium chloride in the presence of dichloroethane solvent, alkali atrefluxing temperature; after the end of reaction, adding water and extracting with dichloromethane, washing the organic phase with water, 4 wt %-˜6 wt % hydrochloric acid solution and NaCl saturated solution in proper order, drying over anhydrous sodium sulfate, evaporating the solvent, and purifying the residue with column chromatography on silica gel using an eluent of PE/EA=20:1˜5:1 to give a concentrated product, i.e. (R)-praziquantel.
[0023] The above alkali may be sodium hydroxide or potassium hydroxide, etc.
[0024] The present invention further provides a product for preventing and/or treating parasitic diseases, the active component of which at least contains the above crystal form of (R)-praziquantel of the present invention.
[0025] According to the present invention, the product includes, but not limited to, an active pharmaceutical ingredient, a pharmaceutical formulation, a premix, and a healthcare product. In the product, the purity of (R)-praziquantel may be 1 wt %-100 wt %. In the product, (R)-praziquantel may be the only active ingredient, and also may be combined with one or more other active ingredients to compose a multi-formula product.
[0026] The present invention further provides a drug composition for preventing and/or treating parasitic diseases, which contains an active component and a pharmaceutically acceptable carrier, wherein the active component at least contains the crystal form of (R)-praziquantel.
[0027] Furthermore, the dosage form of the drug composition is tablets (including coated tablets, sugar-coated tablets, and dispersible tablets), capsules, pills, granules, syrups, aqueous solution injections, powder injections, premix, aerosols, suspensions, solvents or drug rods.
[0028] The solubility of the crystal form of (R)-praziquantel of the present invention in water and simulated gastro-intestinal fluid at the temperature of 25° C. ranges from 0.30˜0.43 mg/mL, which are significantly higher than the solubility of praziquantel (0.19˜0.31 mg/mL). This advantage is greatly favorable for pharmaceutical formulation development of the drug composition.
[0029] In addition, the present invention studied the anti-parasitic activity of the above (R)-praziquantel, and compared the efficacy of anti- schistosomiasis japonica between the crystal form of (R)-praziquantel and a crystal form of praziquantel employing an in vitro culture method. The results showed that both the crystal forms of (R)-praziquantel and praziquantel can induce contraction and paralysis of schistosoma japonicum , however, there was obviously difference between the intensity of inhibition on worm activity of them, and IC 50 of the crystal form of (R)-praziquantel is only ⅕ of that of praziquantel crystal form (P<0.01) (Table 4). The result confirmed that the crystal form of (R)-praziquantel has an apparently higher anti-parasitic activity on schistosoma japonicum than that of praziquantel crystal form.
[0030] For further confirming the anthelmintic effect of (R)-praziquantel crystal form, the curative effect of the (R)-praziquantel crystal form was studied in SD rat disease models artificially infected with clonorchiasis sinensis . Compared to the blank control group, the treatment group of (R)-praziquantel crystal form showed significant therapeutic effect (P<0.01) with the cure rate up to 100% and no worm body found in rat feces.
[0031] For further investigating the pharmacokinetics of products of (R)-praziquantel crystal form in animals, after giving the rats with an oral single dose at 75 mg/kg, the biologic disposition was as follow: the time to reach peak plasma concentration of (R)-praziquantel was 15 minutes, the peak plasma concentration of the drug was 3132±1440 ng/mL, the terminal half life was 0.89±0.19 h, and the area under plasma concentration-time curve was 3572±1793 h·ng/mL. Further comparing the blood concentration characteristics of (R)-praziquantel crystal form and praziquantel crystal form in mice after oral administration, the result showed that: after orally giving the mice with (R)-praziquantel and praziquantel at 100 mg/kg in the two groups of animals respectively, the peak plasma concentrations of (R)-praziquantel both were 15 minutes, the peak concentrations in plasma respectively were 1290 ng/mL and 464 ng/mL, and the areas under plasma concentration-time curves respectively were 667 h·ng/mL and 208 h·ng/mL (see FIG. 6 ). It was thus evident that, after giving the mice with the same oral dose of the drugs, the exposure and the peak plasma concentration of the effective component, i.e. (R)-praziquantel, in (R)-praziquantel crystal form group were apparently higher than those in praziquantel crystal form group, which offers the possibility of safe administration and enhanced therapeutic effect.
[0032] A product containing the crystal form of (R)-praziquantel as an active ingredient has a better solubility than that containing praziquantel, and would be beneficial to prepare the various formulations mentioned above, and ensures the absorption characteristics, the effective bioavailability, the effective plasma drug concentrations as well as the sustainable duration of effective plasma exposure in biological bodies, thus taking advantages in prevention, treatment and healthcare applications and the like.
[0033] The present invention also relates to uses of the crystal form of (R)-praziquantel in preparation of products for preventing and/or treating parasitic diseases.
[0034] The said parasitic diseases include human diseases and animal (pets, livestock, birds, fish and other aquatic animals) diseases.
[0035] The said parasitic diseases include a variety of trematodiasis ( schistosomiasis, clonorchiasis , paragonimiasis, etc.) and various taeniasis.
[0036] A multi-formula product of the present invention combined with other anti-parasitic drugs also can be used for treating nematodiasis, trematodiasis, taeniasis, coccidiosis, trichinelliasis, filariasis, toxoplasmosis, malaria and the like.
[0037] Due to the implementation of the above technical schemes, the present invention has the following advantageous effects when compared to the prior art:
[0038] The present invention provides a crystal form of (R)-praziquantel which is apparently different from the already reported crystal form of praziquantel; the said crystal form of (R)-praziquantel has high purity, excellent physicochemical properties and good reproducibility, and also has stronger parasiticidal activity, better solubility and more characteristic pharmacokinetic properties than similar products of praziquantel crystal forms existing in current market, and thus provides the possibility to develop an anthelmintic drug composition and formulation product of human being and animals, which is more favorable clinically to achieve a more superior anti-parasitic efficacy and safety.
[0039] The present invention further provides a preparation technology of synthesizing (R)-praziquantel and a crystal form thereof. This technology has the advantages of green environmental protection, low cost, capable of operating under normal temperature and pressure, and easy for quality control. The crystallization method thereof can effectively improve the product quality, and can be effectively applied in drug composition preparation, and establishes a reliable foundation for large scale-up production of (R)-praziquantel.
BRIEF DESCRIPTION OF DRAWINGS
[0040] FIG. 1 is an X-ray powder diffraction spectrum of (R)-praziquantel crystal form;
[0041] FIG. 2 is an X-ray powder diffraction spectrum of praziquantel crystal form;
[0042] FIG. 3 is the (R)-praziquantel crystal form observed under polarization microscope;
[0043] FIG. 4 is the praziquantel crystal form observed under polarization microscope;
[0044] FIG. 5 is an infrared absorption spectrum of (R)-praziquantel crystal form;
[0045] FIG. 6 is a DSC thermogram of (R)-praziquantel crystal form;
[0046] FIG. 7 is a concentration-time curve in rat plasma after oral administration of (R)-praziquantel crystal form;
[0047] FIG. 8 is a comparison diagram of plasma concentration-time curves of (R)-praziquantel in mice after orally given with the same dose of (R)-praziquantel and praziquantel.
DETAILED DESCRIPTION OF EMBODIMENTS
[0048] In the following, the present invention is explained in detail combing with the specific embodiments, however, the present invention is not limited to those embodiments.
[0049] Preparation of the Crystal Form of (R)-Praziquantel
[0050] The preparation of the crystal form of (R)-praziquantel includes the following steps:
[0051] (1) Step of preparing intermediate of formula 1 from compound of formula 2a:
[0000]
[0052] in formulas 1, 2a and 2b, X + is the same, and represents counter cation portion of the carboxylic acid ions, and specifically is, for example, H + , K + , Na + or NH 4 + .
[0053] The method of preparing the intermediate of formula 1 is as follow: firstly, compound of formula 2a or 2b and oxygen generate oxidizing reaction under the existing of recombinant D-amino acid oxidase and catalase, and then, the resulted product of the oxidation reaction is reduced to give the intermediate of formula 1 under the action of borane-amine complex.
[0054] (2) Preparing (R)-praziquantel from intermediate of formula 1 according to the following route:
[0000]
[0055] In the above formulas 3 to 7, R is the same, and represents amino protection group.
Example 1
Preparation of recombinant D-amino acid oxidase
[0056] Single colonies of recombinant Escherichia coli containing D-amino acid oxidase gene were inoculated from either a glycerol-containing tube or a transformation plate to a 4 mL LB liquid culture medium containing (100 μg/mL) ampicillin, and activated at 37° C. overnight for 12-16 hours. The activated culture was transferred to 100 mL liquid LB culture medium containing (100 μg/mL) ampicillin at an inoculum size of 2%, and shaking cultured at 37° C. and at 200 rpm until OD 600 reached about 0.6. An inducer isopropyl-β-d-thiogalactopyranoside was added to reach a final concentration of 0.8 mmol/L, and cultured overnight at 30° C. The culture was centrifuged (4° C., 5000 rpm, 15 min) to collect cells which were suspended with 10 mL of phosphate buffer (100 mM, pH 7.0). The cell suspension was sonicated in ice bath for 10 minutes and centrifuged (4° C., 12000 rpm, 15 min). The supernatant liquid was precooled overnight at −20° C., and then cryodesiccated for 34˜40 hours to obtain the freeze-dried powdery and recombinant D-amino acid oxidase.
Example 2
Preparation of intermediate (R)-1,2,3,4-tetrahydroisoquinoline-1-carboxylic acid ammonium salt
[0057] 1.77 g DL-1,2,3,4-tetrahydroisoquinoline-1-carboxylic acid (0.01 mol) was dissolved in 5 mL ammonia (adjusting pH to 8.0), and 1.5 g borane-ammonia complex (0.05 mol) was added. Oxygen was inlet at a uniform speed, and 88.5 mg recombination D-amino acid oxidase and 18 mg catalase were respectively added. Under the condition of stirring, the reaction was generated at 28° C. and the extent of the reaction was detected by HPLC. HPLC showed that after about 28 hours (S)-1,2,3,4-tetrahydroisoquinoline-1-carboxylic acid ammonium salt was less than 1%. The reaction was stopped, and the solution was heated to 50-60° C. for more than half an hour to denature the enzyme protein. The heated reactant was filtered by diatomite to remove the enzyme, the filtrate was diluted by adding 2 times volume of acetone and then filtered to collect precipitated crude product solid which was recrystallized with water/acetone (volume ratio 1/2) to give 1.8 g pure white solid, i.e. compound (R)-1,2,3,4-tetrahydroisoquinoline-1-carboxylic acid ammonium salt, with 99.3% e.e. in 92.5% separation yield.
[0058] The NMR data of the resulted product were as follow: 1 H-NMR (400 MHz, D 2 O, δ ppm): 3.07-3.10 (m, 2H, H-4), 3.45-3.66 (m, 2H, H-3), 4.95 (s, 1H, H-1), 7.29-7.54 (m, 4H, Ph), and the product was confirmed to be (R)-tetrahydroisoquinoline-1-carboxylic acid ammonium salt.
Example 3
Preparation of intermediate (R)-1,2,3,4-tetrahydroisoquinoline-1-carboxylic acid potassium salt
[0059] 1.77 g DL-1,2,3,4-tetrahydroisoquinoline-1-carboxylic acid (0.01 mol) was dissolved in 5 mL K 2 HPO 4 —KH 2 PO 4 buffer solution (adjusting pH to 8.2), and 2.61 g borane-tert-butylamine complex (0.03 mol) was added. Oxygen was inlet at a uniform speed, and 35.5 mg recombinant D-amino acid oxidase and 9 mg catalase were respectively added. Under the condition of stirring, the reaction was generated at 35° C. and the extent of the reaction was detected by HPLC. HPLC showed that after about 30 hours (S)-1,2,3,4-tetrahydroisoquinoline-1-carboxylic acid potassium salt was less than 1%. The reaction was stopped, and the solution was heated to 50-60° C. for more than half an hour to denature the enzyme protein. The heated reactant was filtered by diatomite to remove the enzyme, the filtrate was extracted by toluene (3×5 mL) and the toluene phases were collected to recycle tert-butylamine (2.1 g). The extracted water phase were diluted by adding 2 times volume of acetone, and then filtered to collect precipitated crude product solid which was recrystallized with water/acetone (volume ratio 1/2) to give 1.98 g pure white solid, i.e. compound (R)-1,2,3,4-tetrahydroisoquinoline-1-carboxylic acid potassium salt, with 99.2% e.e. in 91.8% separation yield.
Example 4
Preparation of intermediate (R)-1,2,3,4-tetrahydroisoquinoline-1-carboxylic acid sodium salt
[0060] 1.77 g DL-1,2,3,4-tetrahydroisoquinoline-1-carboxylic acid (0.01 mol) was dissolved in 5 mL NA 2 HPO 4 —NaH 2 PO 4 buffer solution (adjusting pH to 8.0), and 1.77 g borane-dimethyl amine complex (0.03 mol) was added. Oxygen was inlet at a uniform speed, and 53.5 mg recombinant D-amino acid oxidase and 9 mg catalase were respectively added. Under the condition of stirring, the reaction was generated at 37° C. and the extent of the reaction was detected by HPLC. HPLC showed that after about 32 hours (S)-1,2,3,4-tetrahydroisoquinoline-1-carboxylic acid sodium salt was less than 1%. The reaction was stopped, and the solution was heated to 50-60° C. for more than half an hour to denature the enzyme protein. The heated reactant was filtered by diatomite to remove the enzyme, the filtrate was diluted by adding 2 times volume of acetone and then filtered to collect precipitated crude product solid which was recrystallized with water/acetone (volume ratio 1/2) to give 1.86 g pure white solid, i.e. compound (R)-1,2,3,4-tetrahydroisoquinoline-1-carboxylic acid sodium salt, with 99.3% e.e. in 93.1% separation yield.
Example 5
Preparation of intermediate (R)-1,2,3,4-tetrahydroisoquinoline-1-carboxylic acid ammonium salt
[0061] 1.77 g DL-1,2,3,4-tetrahydroisoquinoline-1-carboxylic acid (0.01 mol) was dissolved in 5 mL ammonia solution (adjusting pH to 8.5), and 3.45 g borane-triethylamine complex (0.03 mol) was added. Oxygen was inlet at a uniform speed, and 70.8 mg recombinant D-amino acid oxidase and 12 mg catalase were respectively added. Under the condition of stirring, the reaction was generated at 40° C. and the extent of the reaction was detected by HPLC. HPLC showed that after about 28 hours (S)-1,2,3,4-tetrahydroisoquinoline-1-carboxylic acid ammonium salt was less than 1%. The reaction was stopped, and the solution was heated to 50-60° C. for more than half an hour to denature the enzyme protein. The heated reactant was filtered by diatomite to remove the enzyme, the filtrate was diluted by adding 2 times volume of acetone and then filtered to collect precipitated crude product solid which was recrystallized with water/acetone (volume ratio 1/2) to give 1.81 g pure white solid, i.e. compound (R)-1,2,3,4-tetrahydroisoquinoline-1-carboxylic acid ammonium salt, with 99.3% e.e. in 93.3% separation yield.
Example 6
Preparation of intermediate (R)-1,2,3,4-tetrahydroisoquinoline-1-carboxylic acid potassium salt
[0062] 1.77 g DL-1,2,3,4-tetrahydroisoquinoline-1-carboxylic acid (0.01 mol) was dissolved in 5 mL K 2 HPO 4 —KH 2 PO 4 buffer solution (adjusting pH to 8.2), and 3.48 g borane-tert-butylamine complex (0.04 mol) was added. Oxygen was inlet at a uniform speed, and 47.5 mg recombinant D-amino acid oxidase and 12 mg catalase were respectively added. Under the condition of stirring, the reaction was generated at 35° C. and the extent of the reaction was detected by HPLC. HPLC showed that after about 35 hours (S)-1,2,3,4-tetrahydroisoquinoline-1-carboxylic acid potassium salt was less than 1%. The reaction was stopped, and the solution was heated to 50-60° C. for more than half an hour to denature the enzyme protein. The heated reactant was filtered by diatomite to remove the enzyme, the filtrate was diluted by adding 2 times volume of acetone, and then filtered to collect precipitated crude product solid which was recrystallized with water/acetone (volume ratio 1/2) to give 1.99 g white solid, i.e. compound (R)-1,2,3,4-tetrahydroisoquinoline-1-carboxylic acid potassium salt, with 99.1% e.e. in 92.3% separation yield.
Example 7
Preparation of (R)-1,2,3,4-tetrahydroisoquinoline-1-carboxylic acid
[0063] 1.99 g (R)-1,2,3,4-tetrahydroisoquinoline-1-carboxylic acid potassium salt prepared according to Example 6 was dissolved in 5 mL pure water, and hydrogen chloride gas was inlet into the solution until pH value reached 2-3. 10 mL acetone was added and then filtered to collect precipitated solid which was dried to give 1.59 g (R)-1,2,3,4-tetrahydroisoquinoline-1-carboxylic acid, with 99.1% e.e. in 97% yield.
[0064] The NMR data of the product of this example were as follow: 1 H NMR (DMSO-d6, 400 MHz, δ ppm): 2.87-3.11 (m, 2H, CH 2 CH 2 N), 3.35-3.76 (m, 2H, CH 2 CH 2 N), 5.3 (d, 1H, CHCOOH), 7.24-7.35 (m, 4H, ArH), 9.45 (s, 1H, COOH), and the product was confirmed to be (R)-tetrahydroisoquinoline-1-carboxylic acid.
Example 8
Preparation of (1R)-2-[(tert-butyl) oxycarbonyl]-1,2,3,4-tetrahydroisoquinoline-1-carboxylic acid (compound 4A)
[0065]
[0066] (R)-1,2,3,4-tetrahydroisoquinoline-1-carboxylic acid (80 g, 0.45 mol) dissolved in 845 mL tetrahydrofuran (THF) and Na 2 C
[0067] O 3 (191.5 g, 1.8 mol) dissolved in 845 mL H 2 O were mixed and cooled to 0° C. (Boc) 2 O (108 g, 0.5 mol) dissolved in 280 mL tetrahydrofuran was dropwise added into the solution at 0° C. and then the system was stirred overnight. After the end of reaction, the system was extracted with ethylacetate (EA), and the extracted organic layers were merged, washed with NaCl saturated solution, dried over anhydrate sodium sulfate, and vacuum-evaporated to dryness. The dried residue was purified by silica gel column chromatography with PE/EA=1:1 as the eluent to give a white solid, i.e. compound 4A (106 g, 85% yield).
Example 9
Preparation of (1R)-1-hydroxymethyl-2-[(tert-butyl) oxycarbonyl]-1,2,3,4-tetrahydroisoquinoline (compound 4B)
[0068]
[0069] Under the protection of N 2 , BH 3 (2.0 M, 377 mL, 754 mmol) dissolved in THF was dropwise added into a solution of compound 4A (70.2 g, 0.25 mol) dissolved in 975 mL THF at 0° C. After the adding, the solution was stirred for 3 hours, and NaHCO 3 solution was dropwise added. After the end of reaction, the system was extracted with ethyl acetate, and the merged organic phases were washed with NaCl saturated solution, dried over anhydrate sodium sulfate, and vacuum-evaporated to dryness. The dried residue was purified by silica gel column chromatography with PE/EA=10:1˜5:1 as the eluent, and concentrated to give a faint yellow oily product, i.e. compound 4B (53.3 g, 80% yield).
Example 10
Preparation of tert-butyl (1R)-1-[(1,3-dioxobenzo[c]azolidin-2-yl)methyl]-1,2,3,4-tetrahydroisoquinoline-2-carboxylate (compound 4C)
[0070]
[0071] DIAD (131 g, 0.65 mol) and triphenylphosphine (PPh 3 ) (170 g, 0.65 mol) were respectively added into a solution of compound 4B (85 g, 0.32 mol) dissolved in 1 L dichloromethane (DCM), and the mixture was stirred at room temperature for 30 min and then cooled to 0° C. Phthalimide (52.6 g, 0.36 mol) was added in batches, and the solution was warmed up to room temperature and stirred overnight. After the end of reaction, 1 L water was added, and the solution was extracted with EA, and the merged organic phases were respectively washed with water and saturated salt water, dried over anhydrate sodium sulfate, and vacuum-evaporated to dryness. The dried residue was purified by silica gel column chromatography with PE/EA=200:1˜20:1 as the eluent, and concentrated to give a white solid, i.e. compound 4C (90.0 g, 71% yield)).
Example 11
Preparation of tert-butyl (1R)-1-[(cyclohexylcarbonylamino) methyl]-1,2,3,4-tetrahydro isoquinoline-2-carboxylate (compound 4F)
[0072]
[0073] 60 mL hydrazine hydrate was added into a solution of compound 4C (61 g, 0.15 mol) dissolved in 360 mL ethanol. The mixture was refluxed for 40 min, cooled to room temperature, and then concentrated. 360 mL EA was added, and the solution was stirred for 30 min and filtered to remove the generated solid. The filtrate was concentrated to give a yellow oily compound 4D (41.4 g) used directly in the next step.
[0074] Compound 4D (41.4 g, 0.15 mol) was dissolved in 450 mL THF, and 2 mol/L NaOH solution (300 mL, 600 mmol) was added, and the system was cooled to 0° C. Then a solution of compound 4E (27 g, 0.18 mol) dissolved in 150 mL THF was dropwise added and the solution was stirred for 2 hours, warmed up to room temperature and stirred overnight. After the end of reaction, 600 mL water was added, and the solution was extracted with EA, and the merged organic phases were respectively washed with water and NaCl saturated solution, dried over anhydrate sodium sulfate, and vacuum-dried. The dried residue was purified by silica gel column chromatography with PE/EA=20:1˜10:1 as the eluent, and concentrated to give a white solid, i.e. compound 4F (40.5 g, 70% overall yield for two steps).
Example 12
Preparation of (R)-Praziquantel
[0075]
[0076] Compound 4F (90 g, 0.24 mol) and HCl/EA solution (1.9 L) were stirred at room temperature for 2 hours and checked by LC-MS. After the end of reaction, the solvent was evaporated off. The residue of evaporation was dissolved in DCM, and the solution was respectively washed with saturated sodium bicarbonate (NaHCO 3 ) and NaCl saturated solution, and concentrated to give a white solid 4G (66.9 g). The white solid 4G (66.9 g, 0.24 mol) was dissolved in 250 mL dichloromethane, and then chloroacetyl chloride (30.3 g, 0.26 mol) dissolved in 130 mL dichloromethane and 50% NaOH solution (77 mL) were added, respectively. After stirring for 30 min, benzyl triethyl ammonium chloride (TEBAC, 5.5 g, 0.024 mol) was added, and the mixture was heated to reflux for 2 hours. After the end of reaction, 380 mL water was added, and the mixture was extracted with dichloromethane. The merged organic phases were respectively washed with water for 2 times, with 5% hydrochloric acid solution and with saturated salt water, and dried over anhydrate sodium sulfate. After evaporating off the solvent, the residue was purified by silica gel column chromatography with PE/EA=20:1˜5:1 as the eluent, and concentrated to give a product, i.e. (R)-praziquantel.
[0077] The NMR data of (R)-praziquantel were as follow: 1 H NMR (300 MHz, DMSO-d6): δ 1.26-1.30 (m, 3H), 1.46-1.63 (m, 3H), 1.72-1.88 (m, 5H), 2.43-2.56 (m, 1H), 2.77-2.87 (m, 2H), 2.90-3.25 (m, 2H), 3.84-4.10 (m, 1H), 4.35-4.49 (m, 1H), 4.79-4.87 (m, 2H), 5.15-5.18 (d, 1H), 7.17-7.19 (d, 2H), 7.24-7.28 (d, 2H).
Example 13
Preparation of (R)-praziquantel crystal form
[0078] 0.5 g concentrated product obtained according to Example 12 was dissolved in 3 g acetonitrile (CH 3 CN) at 20° C. The solution was filtered, and the filtrate was kept. 1.5 g acetone and 10 g toluene were added into the filtrate, respectively. Let the system stand at 20° C. overnight, and then it was filtered to give 0.412 g white solid, i.e. crystal form of (R)-praziquantel. The yield was 82.4%, the purity was 99.1%, and the e.e. value was 99.5%. The XRD pattern thereof was as illustrated in FIG. 1 .
Example 14
Preparation of R-praziquantel crystal form
[0079] 0.5 g concentrated product obtained according to Example 12 was dissolved in 3.69 g tetrahydrofuran at 20° C. The solution was filtered, and the filtrate was kept. 8.47 g n-heptane was added into the filtrate, and the system was cooled to 10° C. Let the system stand overnight, and then it was filtered to give 0.466 g white solid, i.e. crystal form of (R)-praziquantel. The yield was 93.2%, the purity was 99.3%, and the e.e. value was 99.2%. The XRD pattern thereof was as illustrated in FIG. 1 .
Example 15
Preparation of (R)-praziquantel crystal form
[0080] 0.5 g concentrated product obtained according to Example 12 was dissolved in 3 g acetic acid isopropyl ester and 10 g ethanol, and the solution was heated to 60° C. and filtered, and the filtrate was kept. 8.6 g cyclohexane was added into the filtrate, and the system was cooled to 30° C. Let the system stand overnight, and then it was filtered to give 0.482 g white solid, i.e. crystal form of (R)-praziquantel. The yield was 96.4%, the purity was 99.4%, and the e.e. value was 99.3%. The XRD pattern thereof was as illustrated in FIG. 1 .
Example 16
Characterization of crystal form of (R)-praziquantel
[0081] 1. Both the crystal form of (R)-praziquantel and the crystal form of praziquantel made previously were analyzed by powder X-ray diffraction (XRPD) analysis; the crystal form of (R)-praziquantel was also analyzed by infrared absorption (IR) method, differential scanning calorimetry (DSC) and optical rotation determination, wherein:
[0082] The preparation method of praziquantel crystal form made previously was as follow: 30 mL methanol and 60 mL water were mixed at room temperature (20° C.), and 0.5 g praziquantel sample was added to the solution and fully dissolved. The solution was heated up to 40° C. and dried under the condition of vacuum to give a white solid, i.e. praziquantel crystal form.
[0083] XRPD measurement employed an EMPYREAN X-ray Diffractometer with CuKα radiation from PANALYTICAL INC. About 10 mg sample was distributed evenly onto a monocrystalline silicon sample pan, and the XRPD measurement was carried out using the parameters in the following table:
[0000]
Start Position [°2Th.]: 3.0012
End Position [°2Th.]: 39.9999
Step Size [°2Th.]: 0.0130
Scan Step time [s]: 20.4000
K-Alpha1 [Å]: 1.54060
K-Alpha2 [Å]: 1.54443
Generator Settings: 40 mA, 45 kV
[0084] Infrared absorption (IR) measurement employed an infrared detector from SHIMADZU, and employed potassium bromide-pellet technique in which blank KBr plates and sample-KBr plates were respectively prepared, and IR measurement was carried out using the parameters in the following table:
[0000]
Measuring Mode: % Transmittance
Apodization: Happ-Genzal
No. of Scans: 40
Resolution: 4 cm −1
Range: 4000-400 cm −1
[0085] DSC measurement was carried out on a TAQ 200 differential scanning calorimeter, and the test parameters were as follow:
[0000]
DSC
Sample Pan
Aluminum Pan, Lid Crimped
Temperature/° C.
25-200° C.
Scanning Rate/(° C./min)
10
Protective Gas
Nitrogen
[0086] The above-mentioned crystal form of (R)-praziquantel was characterized in that, the optical rotation at 20° C.: [α] D =−140.12° (CH 3 OH).
[0087] The differential scanning calorimeter showed that the melting point of the crystal form of (R)-praziquantel was 108.83° C.
[0088] The XRPD patterns of the crystal form of (R)-praziquantel and praziquantel were as illustrated in FIG. 1 and FIG. 2 , respectively. The XPRD diffraction peak data of (R)-praziquantel crystal form is listed in Table 1, and the XPRD data comparison of the strongest 10 diffraction peaks of the crystal forms between (R)-praziquantel and praziquantel are showed in Table 2; when observed under polarizing optical microscope, all samples of (R)-praziquantel crystal form demonstrated birefringence phenomenon in the form of tabular crystal or long rod-like crystal, referring to FIG. 3 , while praziquantel crystal form showed short and small rod-like crystal, referring to FIG. 4 ; the IR spectrum and DSC thermogram of crystal form of (R)-praziquantel are illustrated in FIG. 5 and FIG. 6 , respectively.
[0000]
TABLE 1
XRPD data of (R)-praziquantel crystal form
Angle
d value
Intensity
Intensity %
Caption
2-Theta °
Angstrom
Count
%
1
6.929
12.74616
855
39.2
2
8.329
10.60733
2151
98.6
3
8.667
10.19385
212
9.7
4
12.82
6.8995
166
7.6
5
13.421
6.59225
336
15.4
6
14.08
6.28507
444
20.4
7
15.076
5.87211
2181
100
8
15.724
5.63121
1086
49.8
9
16.611
5.33251
1347
61.8
10
17.4
5.09254
1629
74.7
11
17.875
4.95836
783
35.9
12
18.241
4.85966
373
17.1
13
18.952
4.67892
462
21.2
14
19.795
4.48152
2110
96.7
15
20.591
4.31006
330
15.1
16
21.627
4.10583
560
25.7
17
21.899
4.05534
1510
69.2
18
23.034
3.8581
207
9.5
19
23.781
3.73849
888
40.7
20
24.271
3.66415
1011
46.4
21
25.419
3.50128
136
6.2
22
25.798
3.45069
94
4.3
23
27.43
3.24889
510
23.4
24
27.822
3.20408
136
6.2
25
28.491
3.1303
173
7.9
26
29.022
3.0742
231
10.6
27
29.269
3.04888
184
8.4
28
30.266
2.95061
109
5
29
30.561
2.92283
110
5
30
30.881
2.89324
176
8.1
31
32.4
2.76103
153
7
32
33.727
2.65539
276
12.7
33
34.239
2.61683
85
3.9
34
36.379
2.46765
151
6.9
35
38.423
2.34093
113
5.2
36
39.474
2.28097
682
31.3
[0000]
TABLE 2
Data Comparison of the 10 strongest diffraction peaks of the
crystal forms between (R)-praziquantel and praziquantel
Angle
d value
Intensity
Intensity %
Caption
2-Theta °
Angstrom
Count
%
XRPD data of the strongest 10 diffraction
peaks of (R)-praziquantel crystal form
1
6.929
12.74616
855
39.2
2
8.329
10.60733
2151
98.6
7
15.076
5.87211
2181
100
8
15.724
5.63121
1086
49.8
9
16.611
5.33251
1347
61.8
10
17.4
5.09254
1629
74.7
14
19.795
4.48152
2110
96.7
17
21.899
4.05534
1510
69.2
19
23.781
3.73849
888
40.7
20
24.271
3.66415
1011
46.4
XRPD data of the 10 strongest diffraction
peaks of praziquantel crystal form
3
7.906
11.17382
1367
100
9
12.147
7.28062
514
37.6
12
14.628
6.05086
521
38.1
13
15.24
5.80895
935
68.4
14
16.316
5.42843
1136
83.1
19
18.402
4.81731
676
49.5
21
19.246
4.60806
595
43.5
23
19.958
4.44526
1110
81.2
25
21.091
4.20883
492
36
29
22.495
3.94929
683
50
Example 17
[0089] The measurement of solubility of (R)-praziquantel and praziquantel crystal forms in water and simulated gastric-intestinal fluid, which was described as below:
[0090] About 2 mg of each compound was respectively placed in several glass vials, and pure water, simulated gastric fluid (SGF), simulated intestinal fluid under fasted status (FaSSIF), and simulated intestinal fluid under fed status (FeSSIF) were respectively added to prepare a final sample concentration of 2 mg/mL. The samples were sonicated to be dispersed evenly and then rotated 360 degree-wise to equilibrate for 18 hours at room temperature (25° C.). After the equilibration, the samples were visually inspected to check whether they were completely dissolved, and then filtrated through 45 μm filter membrane. The resulted filtrate was diluted with suitable solvent for HPLC analysis. Two duplicate samples of each matrix were taken into analysis, and the results are listed in Table 3.
[0000]
TABLE 3
Comparison of solubility between (R)-praziquantel and
praziquntel crystal forms in different conditions
Average solubility (mg/mL)
Media
(R)-prazqiuantel crystal form
Praziquantel crystal form
Water
0.305
0.199
SGF
0.303
0.192
FeSSIF
0.433
0.313
FaSSIF
0.302
0.193
Example 18
[0091] Comparison of anti- schistosoma japonicum activity between the crystal forms of (R)-praziquantel and praziquantel in in vitro culture experiment, which was specifically as follow:
[0092] Raw powders of (R)-praziquantel and praziquantel were respectively dissolved in PEG-400 to prepare 2 wt % drug solution. An aliquot of the drug solution (5-50 μL) was transferred and diluted with culture medium (prepared by Tyrode's solution and calf serum at 9:1, pH 7.4, containing 100 IU/mL penicillin and 100 IU/mL streptomycin) to a desired concentration (0.0001-100 μg/mL). Japanese white rabbits and Kunming hybrid mice were infected with cercariae of schistosoma japonicum for 5-8 weeks. Under aseptic condition, mesenteric vein and liver were perfused with normal saline, and the recovered schistosomes were washed with Tyrode's solution twice and then transferred into culture medium and cultured at 37° C. for use. Intact, active and paired worms were selected and transferred at 1 pair/flask into Carlsberg's culture flasks filled with 4 mL culture solutions containing different concentrations of (R)-praziquantel and praziquantel, and cultured at 37° C. for different time periods. The worm activity and changes on body surface were observed under stereomicroscope and inverted microscope at room temperature. The active levels of worm were defined as below:
[0093] ++++ Worm twitching or rolling intensively;
[0094] +++ Worm wriggling or paroxysmally trembling frequently;
[0095] ++ Worm migrating freely with enterocinesia;
[0096] + Movement of worm weakened and enterocinesia disappeared;
[0097] ± No movement of worm was observed under stereomicroscope (×30), and slight movement of mouth and ventral suckers were observed under inverted microscope (×250);
[0098] − No movement of worm was observed under inverted microscope (×250);
[0099] wherein +++ and ++++ refer to worm excitement; ++ refers to normal worm activity; + and ± refers to inhibition of worm activity; worm was considered to death if the result was still negative after observing for 5 min. The results are shown in Table 4.
[0000]
TABLE 4
Comparsion of in vitro activity 1 against schistosoma japonicum
of (R)-praziquantel and praziquantel crystal forms
(R)-praziquantel
Praziquantel
2 IC 50 ± 3 L 95
0.008 ± 0.004
0.042 ± 0.018*
1 Activity: spasm or paralysis of schistosoma japonicum after administration were considered as active;
2 IC 50 : median inhibitory concentration, unit: μM;
3 L 95 : 95% confidence interval.
(*P < 0.01)
Example 19
[0100] Evaluation of in vivo anti-parasitic activity of (R)-praziquantel crystal form in SD rats infected with clonorchis sinensis , which was specifically as follow:
[0101] Each of total 29 SD rats with 200˜300 g of body weight were given with 30 metacercariae of clonorchis sinensis via gavage intragastrically. On Day 35 post infection, fecal smear examination was conducted, and worm eggs of clonorchis sinensis were found in all of the smears which confirmed successful modeling. Subsequently, the rats were randomly divided into (R)-praziquantel group (n=14) and blank control group (n=15). (R)-praziquantel was formulated with PEG-400 to a concentration of 2%, and the rats were dosed at 100 mg/kg via gavage twice a day for two days of continuous treatment, while the rats of the control group were given the same volume of PEG-400 only. Seven days after the end of the treatment, worms are recovered from the bile ducts under sterility condition. The averaged number of recovered worms, mean recovery rate of worms and cure rate after treatment were calculated, and the results are shown in Table 5.
[0000]
TABLE 5
Results of (R)-praziquantel crystal form
in the treatment of clonorchiasis in rat
No. of
Mean
No. of
Cure
Average of
recovery
No. of
Cured
rate,
recovered worm,
rate of
Grouping
Animal
animal
%
X ± SD
worms, %
(R)-
14
14
100
0
0
praziquantel
Blank
15
0
0
8.45 ± 9.57*
28.22*
control
(*P < 0.01)
Example 20
[0102] Investigation on characteristic of the plasma concentrations of (R)-praziquantel crystal form in rats after oral administration, which was specifically as follow:
[0103] Adequate amount of (R)-praziquantel powder was weighed and suspended in 0.5% methylcellulose (MC) solution to form a suspension of 7.5 mg/mL, and then vortexed and sonicated until mixed homogeneously. The rats (N=3) were intragastrically administrated with the drug at 10 mL/kg (i.e. 75 mg/kg). Rat blood samples were collected at predose, and 5 min, 15 min, 30 min, 1 h, 2 h, 4 h, 8 h and 24 h after dose, and the blood samples were centrifuged to obtain plasma samples for drug concentration analysis by HPLC-MS. The results are shown in FIG. 7 . After rats were given with the drug at a single oral-dose of 75 mg/kg, the biological disposition was as follow: the time to reach peak plasma concentration of the drug was 15 min, and the peak plasma concentration was 3132±1440 ng/mL, the terminal half-life was 0.89±1.9 h, and the area under plasma concentration-time curve was 3572±1793 h·ng/mL.
Example 21
[0104] Comparison of characteristics of plasma concentrations after oral administration of (R)-praziquantel and praziquantel crystal forms in mice. The specific method was as follow:
[0105] Adequate amount of (R)-praziquantel or praziquantel powder was weighed and suspended in 0.5% methylcellulose (MC) to form a suspension of 10 mg/mL, and then vortexed and sonicated until mixed homogeneously. The rats (N=3) were intragastrically administrated with the drugs at 10 mL/kg (i.e. 100 mg/kg). Mouse blood samples were collected at predose, and 5 min, 15 min, 30 min, 1 h and 2 h after dose, and the blood samples were centrifuged to obtain plasma samples for drug concentration analysis by HPLC-MS. The results showed that, after orally giving the mice with (R)-praziquantel and praziquantel respectively at 100 mg/kg in the two groups of animals, the time to reach peak plasma concentration of (R)-praziquantel both were 15 minutes, the peak plasma concentrations of the drug were 1290 ng/mL and 464 ng/mL respectively, and the areas under concentration-time curves were 667 h·ng/mL and 208 h·ng/mL respectively (see FIG. 8 ). It was thus evident that, after giving the mice with the same oral dose of (R)-praziquantel and praziquantel, the plasma exposure and the peak concentration of the active component, e.g. the (R)-praziquantel in (R)-praziquantel crystal form group were apparently higher than those in praziquantel crystal form group.
[0106] The embodiments described above are only for illustrating the technical concepts and features of the present invention, and intended to make those skilled in the art being able to understand the present invention and thereby implement it, and should not be concluded to limit the protective scope of this invention. Any equivalent variations or modifications according to the spirit of the present invention should be covered by the protective scope of the present invention. | The present invention relates to a crystal form of (R)-praziquantel and a preparation method and uses thereof. The X-ray diffraction pattern (CuKα radiation) of the crystal form of (R)-praziquantel at 25° C. shows the following diffraction peaks: 2-Theta=6.9±0.2°, 8.3±0.2°, 15.1±0.2°, 17.4±0.2°, 19.8±0.2°, 21.9±0.2°, 24.3±0.2° or d=12.74±0.20 Å, 10.61±0.20 Å, 5.87±0.20 Å, 5.09±0.20 Å, 4.48±0.20 Å, 4.06±0.20 Å, 3.66±0.20 Å. Compared to the existing crystal form of praziquantel, the crystal form of the present invention has better solubility, better drug efficacy and better pharmacokinetic characteristics. The preparation method of the present invention has the following advantages: good reproducibility, environmentally friendly, low cost, and able to operate at a normal pressure and temperature, and suitable for large-scale production. | 2 |
FIELD OF THE INVENTION
[0001] The present invention is directed to new compounds of high optical purity, a process for their preparation and their use as intermediates in the synthesis of the S- or R-enantiomer of 5-methoxy-2-[[(4-methoxy-3,5-dimethyl-2-pyridinyl)methyl]sulphinyl]-1H-benzimidazole.
BACKGROUND OF THE INVENTION
[0002] The compound 5-methoxy-2-[[(4-methoxy-3,5-dimethyl-2-pyridinyl)methyl]sulphinyl]-1H-benzimidazole, having the generic name omeprazole, and therapeutically acceptable alkaline salts thereof are described in EP 5129 and EP 124 495, respectively. Omeprazole and its alkaline salts are effective gastric acid secretion inhibitors, and are useful as antiulcer agents. The compounds, being sulphoxides, have an asymmetric center in the sulphur atom, i.e. exist as two optical isomers (enantiomers). It has been shown that the lo magnesium salt of the S-enantiomer of omeprazole has better pharmacokinetic and metabolic properties compared to omeprazole, and this is described in EP 0 652 872 B1. As a result of this the magnesium salt of the S-enantiomer of omeprazole has an improved therapeutic profile such as a lower degree of interindividual variation.
[0003] In EP 0 773 940 B1 a process for preparation of the single enantiomers of omeprazole and structurally related sulphoxides is described. In this process, a pro-chiral sulphide is oxidised with an oxidising agent in the presence of a chiral titanium complex into the corresponding sulphoxide either as a single enantiomer or in enantiomerically enriched form.
[0004] Single enantiomers of omeprazole in neutral form are difficult to obtain in crystalline state and thus these compounds are most frequently obtained as non crystalline products. In for instance WO 92/08716 the neutral form of the R enantiomer of omeprazole is obtained as an amorphous solid and in WO 94/27988 both of the enantiomers of omeprazole—in their neutral forms—are obtained in the form of syrups or oils. In WO 94/27988 is also described the preparation of alkaline salts of the single enantiomers, which are obtainable as crystalline products. These can be purified by recrystallisation resulting in products of very high optical purity. Furthermore, optically pure salts of the S-enantiomer of omeprazole are stable towards racemization both in neutral pH and basic pH.
[0005] WO 98/28294 discloses S-omeprazole in neutral form that is in a solid state.
[0006] It would be desirable to perform the oxidation of pro-chiral sulphides yielding highly crystalline sulphoxide intermediates, thus making it possible to directly recrystallise the crude sulphoxides in its neutral form in order to increase the optical purity as well as to increase the chemical purity. The purified enantiomerically enriched sulphoxide intermediates could then be converted into the S- or R-enantiomer of omeprazole and thereafter optionally into pharmaceutically acceptable salts thereof. An advantage of such a process is that a requisite chemical and optical purification step would not involve the addition of an alkaline medium to a titanium containing reaction mixture, which process is associated with problems with the formation of inorganic titanium salts that are difficult to work with. A further advantage is if the titanium catalyzed reaction step occurrs earlier in the synthesis of the enantiomerically enriched compounds thereby reducing a possible risk of contamination of the final product by titanium salts.
[0007] The present invention relates to new crystalline sulphoxides which are stable enough to be directly recrystallised, the preparation of these sulphoxides and their use as intermediates in the synthesis of S- and R-enantiomer of omeprazole.
DETAILED DESCRIPTION OF THE INVENTION
[0008] The present invention refers to new highly crystalline sulphoxides in enantiomerically enriched form which are chemically stable enough to be directly crystallised from an oxidation reaction mixture, the preparation of these sulphoxides and their use as intermediates in the synthesis of the S- and R-enantiomer of omeprazole and pharmaceutically acceptable salts thereof.
[0009] According to another aspect of the invention, the new synthetic intermediates are defined by formula I either as a single enantiomer or in enantiomerically enriched form:
wherein
Het is
and X is a leaving group such as a halogen (F, Cl, Br, I), NO 2 , N 2 + or —OSO 2 R (R is CH 3 , CF 3 , p-toluene, m-chlorobenzene, p-chlorobenzene).
[0011] According to another aspect of the invention the leaving group X is chloro or nitro as in the compounds of formula Ia, Ib, Ic and Id:
[0012] The compounds Ia-Id, and their corresponding tautomers, exist either as a single enantiomer or in an enantiomerically enriched form.
[0013] A further aspect of the invention is the preparation of compounds of formula I, which can be used as intermediates in the synthesis of the S- and R-enantiomer of omeprazole and pharmaceutically acceptable salts thereof. The preparation of the compounds of formula I may be carried out as described in EP 0 773 940 B1, and this is also illustrated in Scheme 1 below.
and X is a leaving group such as a halogen (F, Cl, Br, I), NO 2 , N 2 + or —OSO 2 R (R is CH 3 , CF 3 , p-toluene, m-chlorobenzene, p-chlorobenzene).
[0014] In this process, a pro-chiral sulphide such as II is oxidised in an organic solvent with an oxidising agent, e.g. cumene hydroperoxide, in the presence of a chiral titanium complex. The titanium complex suitable for catalysing the process of the invention is prepared from a chiral ligand and a titanium(IV) compound such as preferably a titanium(IV)alkoxide, and optionally in the presence of water. The chiral ligand used in the preparation of the titanium complex is for instance a chiral alcohol such as a chiral diol. The oxidation may be performed in the presence of a base, e.g. N,N-diisopropylethylamine.
[0015] The oxidation is carried out in an organic solvent. The solvent can be chosen with respect to suitable conditions from an industrial point of view as well as environmental aspects. Suitable organic solvents are for instance toluene, ethyl acetate, methyl ethyl ketone, methyl isobutyl ketone, diethyl carbonate, tert.butyl methyl ether, tetrahydrofurane, methylene chloride and the like. From an environmental point of view non-chlorinated solvents are preferred.
[0016] The oxidation is preferably carried out in an organic solvent at room temperature or just above room temperature, e.g. between 20-40° C. If the reaction time is varied a reaction temperature may be chosen below as well as above the preferred temperatures 20-40° C. A suitable temperature range is limited only depending on the decomposition of the compounds, and that the reaction time is dramatically shorter at room temperature than at −20° C. since the sulphides of interest are oxidised very slowly at such a low temperature.
[0017] An oxidising agent suitable for this asymmetric oxidation may be a hydroperoxide, such as for example tert.-butylhydroperoxide or cumene hydroperoxide, preferably the latter. The titanium complex suitable for catalysing the process of the invention is prepared from a chiral ligand and a titanium(IV)compound such as preferably titanium(IV)alkoxide, and optionally in the presence of water. An especially preferred titanium(IV)alkoxide is titanium(IV)isopropoxide or -propoxide. The amount of the chiral titanium complex is not critical. An amount of less than approximately 0.50 equivalents is preferred and especially preferred amount is 0.05-0.30 equivalents. Even very low amounts of complex, such as for instance 0.04 equivalents may be used in the processes according to the present invention with excellent result.
[0018] The titanium complex may also be prepared by reacting titanium tetrachloride with a chiral ligand in the presence of a base.
[0019] The chiral ligand used in the preparation of the titanium complex is preferably a chiral alcohol such as a chiral diol. The diol may be a branched or unbranched alkyl diol, or an to aromatic diol. Preferred chiral diols are esters or tartaric acid, especially (+)-diethyl L-tartrate or (−)diethyl D-tartrate are preferred.
[0020] The chiral titanium complex may be prepared in the presence of the pro-chiral sulphide or before the pro-chiral sulphide is added to the reaction vessel.
[0021] According to one aspect of the invention, the oxidation is carried out in the presence of a base. The base may be an inorganic or an organic base, such as for instance a hydrogen carbonate, an amide or an amine. Amine includes a guanidine or an amidine. Organic bases are preferred and especially suitable bases are amines, preferably triethylamine or N,N-diisopropylethylamine. The amount of base added to the reaction mixture is not critical but should be adjusted with respect to the reaction mixture.
[0022] The preparation of the chiral titanium complex is preferably performed in the presence of the pro-chiral sulphide.
[0023] Other essential features in the preparation of the chiral titanium complex is that the preparation of the complex is performed during an elevated temperature and/or a prolonged time. With an elevated temperature is meant a temperature above room temperature, such as for instance 30-70° C., preferably 40-60° C. A prolonged preparation time is a period of time longer than approximately 20 minutes, preferably 1-5 hours. A suitable period of time for the preparation step depends on the preparation temperature and of the pro-chiral sulphide, optionally present during the preparation of the chiral titanium complex.
[0024] Yet a further aspect of the invention is the conversion of compounds of formula I into the S- and R-enantiomer of omeprazole and pharmaceutically acceptable salts thereof. Scheme 2 and Scheme 3 below describe synthetic routes for converting compound I into the S-enantiomer of omeprazole. The same routes can be applied to convert compund I into the R-enantiomer of omeprazole provided that the chirality of the chiral titanium complex used in the oxidising reaction step is changed to the opposite of that used for making the corresponding S-enantiomer.
[0025] In Scheme 2, the first step is performed as described above. The obtained sulphoxide I may be recrystallised in order to enhance chemical and optical purity. Finally, a substitution reaction with methoxide, e.g. sodium methoxide, yields the S-enantiomer of omeprazole, which may be converted to a pharmaceutically acceptable salt thereof.
[0026] In Scheme 3, the first step is performed as described above. Nucleophilic substitution of the leaving group X with methoxide, e.g. sodium methoxide, is thereafter performed prior to or after reduction of the pyridine-N-oxide to pyridine.
[0027] The compounds of the invention may exist as tautomers. It is to be understood that the present invention encompasses all such tautomers.
[0028] The invention is illustrated by the following non-limiting examples.
EXAMPLE 1
Synthesis of (S)-2-[[(4-chloro-3,5-dimethy-2-pyridinyl)methyl]sulfinyl]5-methoxy-1H-benzimidazole
[0029] 1.2 g (3.6 mmol) of 2-{[(4-chloro-3,5-dimethyl-2-pyridinyl)methyl]thio}-5-methoxy-1H-benzimidazole was mixed with toluene (40 mL). The mixture was concentrated until half to the volume was left. Water (38 mg, 2.1 mmol), (S,S)-diethyl tartrate (1.85 g, 9.0 mmol) and titanium tetraisopropoxide (1.0 g, 3.6 mmol) were added in the given order while stirring. The mixture was then stirred at 50° C. for an hour and then N,N-diisopropylethylamine (0.46 g, 3.6 mmol) was added at room temperature. After 15 minutes cumene hydroperoxide (80% in cumene, 0.69 g, 3.6 mmol) was added dropwise is and stirring was then continued for 2 h at room temperature. The optical purity of crude sulfoxide turned out to be 75% ee as determined by chiral HPLC analysis of the solution. The mixture was washed with water and then evaporated. The product was purified by chromatography on silica gel using methanol/dichloromethane as eluent (gradient, 1-7% MeOH) and this afforded 1.0 g of a crude product as a solid. Recrystallisation from hot acetonitrile gave 0.35 g of a white solid with an enantiomeric excess of 51%. Next, the mother liqueur from the filtration was concentrated and this material was then also recrystallised from acetonitrile to give 0.35 g of the title compound as a crystalline product with an enantiomeric excess of 92.5%.
[0030] 1 H NMR of the most enriched fraction (92.5% ee) in chloroform-d; 2.3 (s, 3H), 2.4 (s, 3H), 3.8 (s, 3H), 4.8 (AB-system, 2H), 7.0 (dd, 1H), 7.0 (b, 1H), 7.5 (b, 1H), 8.2 (s, 1H).
EXAMPLE 2
Synthesis of (S)-2-[[(4-nitro-3,5-dimethyl-2-pyridinyl)methyl]sulfinyl]5-methoxy-1H-benzimidazole
[0031] In an analogous experiment as in Example 1—starting from 1.2 g of (S)-2-[[(4-nitro-3,5-dimethyl-2-pyridinyl)methyl]thio]5-methoxy-1H-benzimidazole—1.0 g of the title compound as a crystalline product was obtained. The enantiomeric excess of this crude product was determined to be 48% by chiral HPLC analysis. | The present invention relates to an improved method for the synthesis of the (S)- or (R)-enantiomer of omeprazole, characterized in that 2-[[(4-X-3,5-dimethylpyridin-2-yl)methyl]thio]-5-methoxy-1H-benzimidazole or 2-[[(4-X-3,5-dimethyl-1-oxidopyridin-2-yl)methyl]thio]-5-methoxy-1H-benzimidazole, wherein X is a leaving group, is oxidized into the corresponding sulphoxide which is obtained as a crystalline compound. Recrystallisation of the thus obtained sulphoxide results in a compound of enhanced chemical and optical purity, which is subsequently transformed into the (S)- or (R)-enantiomer of omeprazole. | 2 |
BACKGROUND OF THE INVENTION
The present invention relates to an imaging tube which can favorably be used to amplify and observe a diminished-light image, to a streaking tube which can favorably be used to analyze the light intensity distributions of light sources with elapsing of time, and to a method of fabricating these types of imaging and streaking tubes.
The configuration of the conventional imaging tube and the problems to be solved in accordance with the present invention will be described in relation to FIG. 1.
FIG. 1 shows a cross-sectional view of the conventional imaging tube together with the interrelation between the photoelectric layer and optical image.
One end of a vacuum envelope 3 of the imaging tube constitutes an incident window 1 upon which the optical image to be analyzed can be incident, and another end constitutes a light emitting window 2 from which the processed optical image can be emitted. Photoelectric layer 4, focusing electrode 6, aperture electrode 7, micro-channel-plate 8, and phosphor layer 9 are, in sequence, arranged in a space between incident window 1 and light emitting window 2 along the tube axis of vacuum envelope 3. A higher DC voltage is applied to focusing electrode 6 with respect to photoelectric layer 4, and another higher DC voltage to aperture electrode 7 with respect to focusing electrode 6. A DC voltage which is the same as or a little higher than that applied to aperture electrode 7 is applied to input electrode 8a of micro-channel-plate 8, and a higher DC voltage than that applied to input electrode 8a is applied to output electrode 8b of micro-channel-plate 8. A further higher DC voltage than that applied to output electrode 8b of micro-channel-plate is applied to phosphor layer 9.
We assume that optical image 4a is incident onto photoelectric layer 4 via incident window 1 in the setup not shown. Photoelectric layer 4 emits an electron image corresponding to the optical image, and the emitted electrons are accelerated and focused by focusing electrode 6. They pass through both aperture electrode 7 and micro-channel-plate 8, and arrive at phosphor layer 9 to be focused thereon.
Micro-channel-plate 8 consists of a strand of approximately 10 6 fine glass tubes each having a secondary electron emitting surface of lead oxide deposited on its inner wall. Each fine glass tube, having an inner diameter of 15 μm, is 0.9 mm long. The strand has a diameter of 25 mm.
The incident electrons are multiplied by the micro-channel-plate 8 and then the multiplied electrons are emitted from the micro-channel-plate 8. The multiplication factor depends on the voltage difference between input electrode 8a and output electrode 8b. When the voltage difference between input electrode 8a and output electrode 8b changes from 1.3 kV to 1.9 kV, the multiplication factor goes from 10 3 to 3×10 6 .
Such an imaging tube as described above can be fabricated by the following method.
At first, a glass cylinder to form the wall of vacuum envelope 3 and one end of vacuum envelope 3 are constructed. Next, a first glass disc for forming a photoelectric layer on which the optical image is incident, and the other end of vacuum envelope 3 are constructed. Materials used for the envelope, i.e., a second glass disc wherein a light emitting window used to emit the optical image therefrom is formed and whereon the phosphor layer is formed, and elements used for making such electrodes as mesh electrode 5, focusing electrode 6, aperture electrode 7, and micro-channel-plate 8 are prepared. Elements used for making the electrodes are then fastened within the glass cylinder. At that time, antimony metal contained within a tungsten coil to form an evaporation source of antimony is located against the photoelectric layer substrate.
Phosphor materials are coated on one surface of the second glass disc. First and second glass discs are located at the appropriate ends of the glass cylinder, and then the resulting envelope is exhausted to obtain a vacuum.
A branching tube is fastened to the side wall of the sealed envelope and an alkaline metal source is housed in this branching tube. Air is then exhausted from the sealed envelope via the exhausting tube attached thereto.
A current is applied to flow through the tungsten coil so that antimony metal is deposited onto the photoelectric layer substrate. Alkali metal is gradually fed from the branching tube into the envelope, while the sensitivity of the photoelectric layer is being monitored, until the maximum sensitivity can be obtained. Thereafter, the branching tube is cut off. Then, the exhausting tube is also cut away to complete the imaging tube.
It can easily be understood from the description of the fabrication method that a small amount of alkali metal necessarily adheres to each electrode while alkali metal is being fed to the sealed envelope.
When an imaging tube fabricated in accordance with this process is operated, the phosphor layer sometimes emits light due to a decrease in the work function by the alkali metal when no light is incident upon the photoelectric layer.
When a high voltage is applied to microchannel-plate 8, this mode of light emission is especially enhanced.
This mode of light emission causes the S/N ratio to decrease affecting the background noise for the image, and it makes the dynamic range low.
The inventors of the present invention found that the phosphor layer emitted light without any incident light when a voltage was applied only to the phosphor layer of the micro-channel-plate unless voltages were applied to the imaging section consisting of a photoelectric layer, a focusing electrode, and an aperture electrode. They also found that the objectionable light emission was caused by existence of the micro-channel-plate. Furthermore, they found that the background sensitivity was not increased when a set of voltage was applied to the respective electrodes after the envelope was exhausted and sealed for making a tube of the same dimensions providing no photoelectric alkali layer. The above phenomena suggests that generated electrons increase the background sensitivity due to the following reasons:
Alkali metal adheres to the inner surface of the micro-channel-plate which multiplies secondary electrons, while the photoelectric layer is being formed, and it decreases the work function of electrons at the surface. When a voltage is applied to the micro-channel-plate during operation, high electric fields are locally generated at microscopic locations of non-uniform areas on the inner surface thereof. Interaction of both the low work functon and high electric field causes the inner surface of the micro-channel-plate to emit electrons.
Electrons generated due to field emission are multiplied by the micro-channel-plate and incident upon the phosphor layer to cause the unwanted background sensitivity to increase.
The streaking tube can convert the incident light pulse with a duration of 1 ns into a length on the order of several tens of millimeters on the phosphor layer, and it has an excellent timing resolution of 2 pico seconds or less. The streaking tube is thus widely used for analyzing the waveforms of the laser pulses.
Next, the streaking tube in accordance with the present invention will be described hereafter.
The configuration of the conventional streaking tube and the problems to be solved in accordance with the present invention will briefly be described in relation to FIG. 2.
FIG. 2 shows a cross-sectional view of the conventional streaking tube together with the interrelation between the photoelectric layer and optical image.
One end of a vacuum envelope 3 of the streaking tube constitutes an incident window 1 upon which the optical image to be analyzed can be incident, and another end constitutes a light emitting window 2 from which the processed optical image can be emitted. Photoelectric layer 4, mesh electrode 5, focusing electrode 6, aperture electrode 7, deflection electrode 108, and phosphor layer 9 are, in sequence, arranged in a space between incident window 1 and light emitting window 2 along the tube axis of vacuum envelope 3. A higher DC voltage is applied to mesh electrode 5 with respect to photoelectric layer 4, another higher DC voltage to focusing electrode 6 with respect to mesh electrode 5, and a further higher DC voltage to aperture electrode 7 with respect to focusing electrode 6. A DC voltage which is the same as or a little higher than that applied to aperture electrode 7 is applied to phosphor layer 9.
We assume that linear optical image 4a which lies in the center of the photoelectric layer 4 is incident onto photoelectric layer 4 via incident window 1 in the setup not shown. Photoelectric layer 4 emits an electron image corresponding to the optical image, and the emitted electrons are accelerated by mesh electrode 5 and focused by focusing electrode 6. They pass through both aperture electrode 7 and deflection electrode 108 and arrive at phosphor layer 9 to be focused thereon.
While the linear electronic image is passing through a gap within deflection electrode 108, a deflection voltage is applied to the deflection electrode 108. The electric field caused by this deflection voltage is normal to both the tube axis and linear electronic image. (Note that the electric field is normal to the plane of the drawing in FIG. 2.) The field strength is proportional to the deflection voltage. The electron beam on phosphor layer 9 travels normal to the linear electronic image when scanned. A series of sequential linear optical images are arranged onto photoelectric layer 4 in a direction perpendicular to the linear images, and thus a streaking image is formed. Brightness changes in the direction that a series of linear optical images are arranged or that scanning is being carried out indicates a change in intensity of the optical image incident on phosphor layer 4.
Such a streaking tube as described above can be fabricated by the following method:
At first, a glass cylinder to form the wall of vacuum envelope 3 and one end of vacuum envelope 3 are constructed. Next, a first glass disc for forming a photoelectric layer on which the optical image is incident, and the other bottom of vacuum envelope 3 are constructed. Materials used for the envelope, i.e., a second glass disc wherein a light emitting window used to emit the optical image therefrom is formed and whereon the phosphor layer is formed, and elements used for making such electrodes as mesh electrode 5, focusing electrode 6, aperture electrode 7, and deflection electrode 108 are prepared. Elements used to make the electrodes are then fastened within the glass cylinder. At that time, antimony metal contained within a tungsten coil to form an evaporation source of antimony is located against the photoelectric layer substrate.
Phosphor materials are coated on one surface of the second glass disc. First and second glass discs are located at the appropriate ends of the glass cylinder, and then the resulting envelope is exhausted to obtain a vacuum.
A branching tube is then fastened to the side wall of the sealed envelope and an alkaline metal source is housed in this branching tube. Air is exhausted from the sealed envelope via the exhausting tube attached thereto.
A current is applied to flow through the tungsten coil so that antimony metal is deposited onto the photoelectric layer substrate. Alkali metal is gradually fed from the branching tube to the envelope, while the sensitivity of the photoelectric layer is being monitored, until the maximum sensitivity is obtained. Thereafter, the branching tube is cut off. Thereafter, the exhausting tube is cut away to complete the streaking tube.
It can easily be understood from the description of the fabrication method that a small amount of alkali metal necessarily adheres to each electrode while alkali metal is being fed to the sealed envelope.
When a streaking tube fabricated in accordance with this process is operated, the phosphor layer sometimes emits light due to a decrease in the work function by the alkali metal when no light is incident upon the photoelectric layer.
When an RF voltage is repetitively applied to deflection electrode 108, this mode of light emission is especially enhanced.
This mode of light emission causes the S/N ratio to decrease affecting the background noise for the streaking image, and it makes the dynamic range low.
The inventors of the present invention studied the photoelectrons, on the photoelectric layer, which were generated due to light emitted by excitation or ionization of gaseous molecules or atoms which had collided with electrons, or by collision of electrons or ions with the sealed envelope, and they found that the main reason for their generation was caused by the effect of the deflection electrode on the dynamic range.
We found that, unless a voltage was applied across a pair of deflection electrodes although a high DC voltage was applied across photoelectric layer 4 and aperture electrode 7, light emission occurring in phosphor layer 9 was diminished in intensity while enhanced by the repetitive sweep voltage applied across the deflection electrode.
SUMMARY OF THE INVENTION
An objective of the present invention is to provide an imaging tube which is free from an unwanted light emission as explained before.
In order to practice this objective of the present invention, the imaging tube provides a micro-channel-plate to multiply photoelectrons emitted from the photoelectric layer thereof and to observe the diminished light image obtained by the multiplied photoelectrons. It consists of a separation wall with a window on the tube axis, arranged at or near the crossover point of photoelectrons between the photoelectric layer and micro-channel-plate, a lid movable between the positions to close and open the window, and means to move the lid into the open position; and it is characterized in that the lid is opened to form a path along which electrons can move during operation and is closed only while the photoelectric layer is being formed.
A secondary objective of the present invention is to present a method of fabricating the imaging tube.
In order to practice the secondary objective of the present invention, the method of fabricating the imaging tube providing the micro-channel-plate to multiply photoelectrons emitted from the photoelectric layer and to observe the diminished light image obtained by the multiplied photoelectrons consists of an assembling process providing a lid to separate first a space including at least one surface, to form a photo electric layer thereon with the envelope kept in a vacuum after the envelope is exhausted, and a focusing electrode from a second space including at least a micro-channel-plate and a phosphor layer when the opening is arranged on the tube axis at or near the crossover point of photoelectrons on the separation wall of the envelope, and to close the opening during fabrication; an exhausting process to exhaust the first and second spaces; a photoelectric layer forming process to form a photoelectric layer while introducing alkali metal to form the photoelectric layer via the branching tube into the first space; an ejection process to cut the branching tube, to exhaust the envelope while the envelope is being heated, and to eject the photoelectric layer forming marterials which do not contribute to formation of the photoelectric layer; and a removing process to remove the lid from the opening after completion of exhausting operations.
The first space is designed to be filled with alkali metal vapor for forming the photoelectric layer during fabrication, and the second space is designed to protect the micro-channel-plate against covering of alkali metal vapor during this period of time.
By connecting the first space providing the photoelectric layer with a minimum opening to the second space providing the micro-channel-plate during operation, travelling of alkali metal is suppressed during operation.
The micro-channel-plate is not designed to be contaminated by residual alkali metal during operation.
Even if light emission has occurred due to ionization near the micro-channel-plate or due to collision of electrons at the inner wall of the sealed envelope, the micro-channel-plate is designed so that the incident light does not arrive at the photoelectric layer and this prevents the phosphor layer from emitting unwanted light emission.
A third objective of the present invention is to present a streaking tube which is free from unwanted light emission as described before.
In order to practice this third objective of the present invention, the streaking tube uses a deflection electrode to scan photoelectrons emitted from the photoelectric layer thereof and to observe the diminished light image obtained by the deflected photoelectrons. It consists of a separation wall with a window on the tube axis, arranged at or near the cross over point of photoelectrons between the photoelectric layer and the deflection electrode, a lid movable between the positions to close and open the window, and means to move the lid into the open position; and it is characterized in that the lid is opened to form a path along which electrons can move during operation and is closed only while the photoelectric layer is being formed.
A fourth objective of the present invention is to present a method of fabricating the streaking tube.
In order to practice this fourth objective of the present invention, the method of fabricating the streaking tube using a deflection electrode to deflect photoelectrons emitted from the photoelectric layer and to observe the diminished light image obtained by the deflected photoelectrons consists of an assembling process providing a lid to separate a first space including at least one surface, to form a photoelectric layer thereon within the envelope kept in a vacuum after the envelope is exhausted, and a focusing electrode from a second space including at least a deflection electrode and a phosphor layer when the opening is arranged on the tube axis at or near the crossover point of photoelectrons on the separation wall of the envelope, and to close the opening during fabrication; an exhausting process to exhaust the first and second spaces; a photoelectric layer forming process to form a photoelectric layer while introducing alkali metal to form the photoelectric layer via the branching tube into the first space; an ejection process to cut the branching tube, to exhaust the envelope while the envelope is being heated, and to eject the photoelectric layer forming materials which do not contribute to forming the photoelectric layer; and a removing process to remove the lid from the opening after completion of exhausting operations.
The first space is designed to be filled will alkali metal vapor for forming the photoelectric layer during fabrication, and the second space is designed to protect the deflection electrode against the covering of alkali metal vapor during this period of time.
By connecting the first space providing the photoelectric layer with a minimum opening to the second space providing the deflection electrode during operation, travelling of alkali metal is suppressed during operation.
The deflection electrode is not designed to be contaminated by residual alkali metal during operation.
Even if light emission has occurred due to ionization near the deflection electrode or due to collision of electrons at the inner wall of the sealed envelope, the deflection electrode is designed so that the incident light does not arrive at the photoelectric layer and this prevents the phosphor layer from emitting light emission.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a cross-sectional view of the configuration of the conventional imaging tube, together with the interrelation between the photoelectric layer and optical image.
FIG. 2 shows a cross-sectional view of the configuration of the conventional streaking tube together with the interrelation between the photoelectric layer and optical image.
FIG. 3 shows a cross-sectional view of the imaging tube during the process of fabricating the imaging tube in accordance with the present invention.
FIG. 4 shows a cross-sectional view of the streaking tube during the process of fabricating the streaking tube in accordance with the present invention.
FIGS. 5A and 5B are explanatory views showing the configuration of a separation wall and lid of the tube used in the embodiments shown in FIGS. 3 and 4.
FIGS. 6A, 6B and 6C are explanatory views showing another configuration of the separation wall and lid of the tube.
FIGS. 7A, 7B and 7C are views illustrating third configuration of the separation wall and lid of the tube.
FIGS. 8A, 8B, 8C and 8D are views showing a fourth configuration of the separation wall and lid of the tube.
FIGS. 9A and 9B show dynamic chacteristics of the imaging tube in accordance with the present invention as compared to that for the equivalent conventional imaging tube.
FIGS. 10A and 10B show the dynamic characteristics of the streaking tube in accordance with the present invention as compared to that for the equivalent conventional streaking tube.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 3 shows a sectional view of an imaging tube in the process of being fabricated in accordance with the present invention. In the figure, the numerals as in FIG. 1 indicate the same elements in the imaging tube.
First, the configuration of the imaging tube shown will be described.
In the imaging tube in accordance with the present invention, separation wall 30 divides a sealed vacuum envelope 3 into a space including photoelectric layer 4, mesh electrode 5, focusing electrode 6, and aperture electrode 7 and another space including micro-channel-plate 8 and phosphor layer 9.
Likewise, FIG. 4 shows a sectional view of the streaking tube in the process of being fabricated in accordance with the present invention. In this figure, the same numerals as in FIG. 2 indicate the same elements in the streaking tube.
First, the configuration of the streaking tube will be described.
In the streaking tube in accordance with the present invention, separation wall 30 divides a sealed vacuum envelope 3 into a space including photoelectric layer 4, mesh electrode 5, focusing electrode 6, and aperture electrode 7 and another space including deflection electrode 108 and phosphor layer 9.
Both in the imaging tube and the streaking tube shown in FIGS. 3 and 4, respectively, separation wall 30 provides opening 13 which can mate with a lid 14.
FIG. 5(A) shows lid 14 covering opening 13, and FIG. 5(B) shows lid 14 not covering opening 13.
Lid 14 is revolvable around pin 15 fastened to wall 30. Lid 14 covers opening 13 during fabrication, as shown in FIGS. 3 and 5(A), and lid 14 is clamped by leaf spring 16 fastened to separation wall 30 after the fabrication processes are completed. The center of opening 13 lies on the tube axis, and is arranged at or near crossover point 11 at which the photoelectron beam is focused.
Referring to FIGS. 3 and 4, the method of fabricating the imaging tube and the streaking tube will be described hereinafter.
Exhausting tube 19 leading to a vacuum pump, not shown, is provided in the first space wherein photoelectric layer 4, mesh electrode 5, focusing electrode 6, and aperture electrode 7 are arranged.
Exhausting tube 20 is provided in the second space, within a sealed vacuum envelope, wherein micro-channel-plate 8 in FIG. 3 or deflection electrode 108 in FIG. 4 and phosphor layer 9 are arranged.
The first and second spaces are separated by closing the opening 13 on the separation wall with the lid during fabrication.
Branching tube 17 to store alkali metal and branching tube 18 to store antimony evaporation sources are respectively connected together via the first space.
First, the respective spaces within the envelope are exhausted until a predetermined vacuum is obtained.
Second, the antimony evaporation source is taken out of branching tube 18 by means of a magnetic force. The antimony is heated by a current and evaporated onto photoelectric layer substrate 1.
Third, alkali metal evaporated from branching tube 17 is to reacted with the antimony on photoelectric layer substrate 1.
Fourth, branching tube 17 for storing the alkali metal is cut off when the maximum sensitivity is obtained on the photoelectric layer during monitoring operations.
Fifth, branching tube 18 for storing the antimony evaporation source is cut off.
Finally, the envelope is heated to stabilize the photoelectric layer. Excessive alkali metal is thus exhausted from envelope 3. Thereafter, exhausting tubes 19 and 20 are cut. Then, the imaging tube is completed.
When the imaging tube face is set down in the reverse direction after the tube is completed, lid 14 is automatically moved beneath opening 13 due to the force of gravity. One end of lid 14 is clamped by leaf spring 16 and fastened there. FIG. 5(B) shows the outside view of the lid when the tube face goes down.
FIG. 6 shows a second embodiment of the separation wall and lid of the imaging or streaking tube.
In this embodiment, lid 14 is fastened by bimetal 42 to a supporting rod arranged around separation wall 30. When the imaging or streaking tube is kept at room temperature, lid 14 does not cover opening 13. See FIG. 6(C) for details. While alkali metal is being fed to the photoelectric layer, bimetal 42 heated at about 200° C. is bent as shown in FIG. 6(B). Bent bimetal 42 causes lid 14 to cover opening 13.
Even though such configuration as described above is employed, lid 14 protects the alkali metal against thrusting into the second space.
FIG. 7 shows a third embodiment of the separation wall and lid of the tube.
Lid 14 is fastened in a revolvable way to rod 51 supported around rotation axis 50 on separation wall 30.
Head member 52 of a ferromagnetic material is fastened to the other end of revolvable rod 51, and is kept at the position indicated by FIGS. 7(A) and 7(B) so as to cover opening 13. Head member 52 is held at a different position where opening 13 is kept opened as shown in FIG. 7(C) by means of leaf spring 53 when an external magnetic force is applied to the head member after completion of fabrication, or when the tube is placed in a different attitude.
FIG. 8 shows a fourth embodiment of the separation wall and lid of the tube.
FIG. 8(A) and 8(B) depict the state of the lid during fabrication, and FIG. 8(C) depicts the state of the lid during use of the tube.
Lid 14 is attached to opening 13 of separation wall 30 by means of leaf spring 61 during fabrication. 60 indicates a frame to accept lid 14, and it can accept lid 14 after completion of fabrication. Leaf spring 16 has a claw at its tip 61a. The claw contacting the shoulder of lid 14 protects lid 14 against moving.
The imaging or streaking tube in accordance with the present invention is arranged and fabricated in such a manner as described above. Thus, alkali metal cannot be fed to the microchannel-plate or deflection electrode while the photoelectric layer is being formed. Light emission occurring in micro-channel-plate 8 or deflection electrode 108 seldom arrives at the photoelectric layer due to existence of separation wall 30 while the tube is being raised, and thus the problem of unwanted light emission can be solved by the technique in the present invention.
An image on the phosphor layer of the imaging tube fabricated in accordance with the present invention was compared with that on the phosphor layer of the imaging tube with the same dimensions fabricated in accordance with the prior art technique. The result of comparison will be described hereafter with reference to FIG. 9.
A voltage of 1.3 to 1.9 kV was applied across input electrode 8a and output electrode 8b of micro-channel-plate 8 unless light was incident upon photoelectric layer 4, and an electron current flowing into phosphor layer 9 was measured.
FIG. 9(B) shows a graph of dark currents for the imaging tube fabricated in accordance with the processes mentioned above, whereas FIG. 9(A) shows a graph of dark currents for the imaging tube with the same dimensions built in such a manner that the first space is not shielded from the second space.
The conventional imaging tube depicted on a graph in FIG. 9(A), had a dark current of 5×10 -10 A when a voltage of 1.4 kV was applied across input electrode 8a and output electrode 8b of micro-channel-plate 8 and it had a dark current of 2×10 -8 A when a voltage of 1.9 kV was applied.
When the dark current became 10 -9 A, a number of bright spots appeared over the entire surface of the phosphor layer. When the dark current became 2×10 -8 A, light emission over the entire surface of the phosphor layer became saturated and the light signal could not be displayed even though incident upon the photoelectric layer.
The imaging tube in accordance with the present invention, depicted on a graph in FIG. 9(B), had a dark current of 2×10 -11 A when a voltage of 1.7 kV was applied cross input electrode 8a and output electrode 8b of micro-channel-plate 8 and it had a dark current of 2×10 -10 A when a voltage of 1.9 kV was applied. The dark current was drastically decreased when compared to the conventional imaging tube.
The photoelectric layer of the streaking tube was irradiated by the light pulse source (of a mode lock dye laser emitting light at a frequency of 130 MHz). A sine wave voltage synchronized with the light pulse was repetitively applied to the deflection electrode.
FIG. 10(A) compares the output signal of the streaking tube in accordance with the present invention with that of the conventional streaking tube.
Brightness at the valley of the curve for the conventional streaking tube in FIG. 10(A), which causes the background noise, is 90% of that at its peak.
Whereas, brightness at the valley of the curve for the streaking tube in accordance with the present invention in FIG. 10(B), which causes the background noise, is 1% of that at its peak and the latter can be disregarded as compared with the former.
Although the typical imaging tube is described in the specification, the scope and spirit of the present invention covers modification of the imaging of the same type.
It is easily understood by persons skilled in the art that a two-dimensional device such as the charge coupled device (CCD) or position sensitive device (PSD) can be used in place of phosphor layer 9 to increase the S/N ratio, and that the former has the same effect on sensitivity as compared to the latter.
Furthermore, it is easily understood that alkali metal does not contaminate the internal junction of the CCD or PSD and it does not degrade its electrical performance. | An imaging tube for amplifying and observing a diminished light image and a streaking tube for analyzing the light intensity distributions of light sources with elapsing of time. In order to avoid adhesion of alkali metal to the micro-channel-plate in fabrication of the imaging tube and to avoid adhesion of alkali metal to the deflection electrode in the streaking tube, a separation wall and a lid movable on the separation wall are used. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to and has amont its objects to a novel immune serum globulin and novel methods for its production. Particularly, the invention is concerned with an immune serum globulin having a high titer of naturally occurring antibody to cytomegalovirus (CMV). Further objects of the invention will be evident from the following description wherein parts and percentages are by weight unless otherwise specified.
2. Description of the Prior Art
Hyperimmune serum globulins, i.e., immune serum globulins having high titers of a particular antibody, are thereapeutically useful in treating patients deficient or in need of that particular antibody. For example, tetanus hyperimmune globulin is useful in treating tetanus, and rabies hyperimmune globulin, rabies. It is well known that hyperimmune serum globulins can be produced from plasma or serum obtained from selected donors who have significantly higher titers for a specific antibody than is normally found in the average population. These donors have either been recently immunized with a particular vaccine (U.S. Pat. No. 4,174,388) or else they have recently recovered from an infection or disease [Stiehm, Pediatrics, Vol. 63, No. 1, 301-319 (1979)].
Although clinical disease from cytomegalovirus (CMV) is not common among the general population, it is encountered very frequently in certain susceptible groups of patients. Immumosuppressed organ transplant and cancer patients have been identified as having an unusually high risk of acquiring severe, and sometimes fatal, CMV infection.
Zaia et al in The Journal of Infectious Diseases, Vol. 137, No. 5, 601-604 (1978) disclosed a practical method for preparation of Varicella-Zoster (VZ) Immune Globulin. Outdated blood was screened for complement-fixing antibody to VZ virus. About 15% of the plasma units has a complement-fixation titer equal to or greater than 1:16, with about 7.5% greater than or equal to 1:32.
SUMMARY OF THE INVENTION
We have found that normal fresh plasma from donors who have not been vaccinated with a CMV vaccine can be screened for higher than normal titers of antibody to CMV. Those plasmas with antibody titers greater than about 1:60,000, determined by means of an enzyme-linked immunosorbent assay (ELISA), can be pooled and then fractionated to give a CMV hyperimmune serum globulin. This result is surprising because it is unexpected that plasma from normal, unvaccinated donors would have a titer of antibody to CMV high enough to yield a CMV hyperimmune globulin which would be effective in treating CMV infections.
One obvious advantage of the invention is that normal donors need not be given a CMV vaccine. Consequently, the risks inherent in such a practice are avoided. Another advantage of the invention is that the hyperimmune globulin given intravenously makes antibodies to CMV immediately available. Another advantage resides in avoiding patient discomfort associated with intramuscular administration. Other advantages are elimination of a delay of several days for CMV antibodies to reach a peak in the circulation, and elimination of local degradation. Furthermore, less product needs to be administered intravenously in order to achieve the same level of antibody obtained with an intramuscularly administered product or higher doses can be administered intravenously to provide higher titers which would otherwise be impossible to obtain by intramuscular administration.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
These and other advantages of the present invention may be obtained in the following manner.
Normal plasma from a donor is tested for naturally occurring antibody to CMV employing an ELISA or other equally sensitive screening method at equivalent titer. To be effective the plasma from such donors should have a titer of antibody to the CMV equal to or greater than about 1:60,000. We have found that about 4-8% of plasma donors in fact have such a titer. These donations may be selected from a routine donor collection by random screening. Generally, the hyperimmune serum globulin of the invention has a titer of antibody to CMV of about 1:150,000-1:1,225,000, preferably about 1:450,000-1:615,000.
The method of screening the plasma, i.e. the ELISA method, is essentially as described by Engvall and Perlmann, J. Immunol., 109, 129-135 (1972), Engvall et al, Biochemica Et Biophysica Acta, 251 (1971) 427-434, Engvall et al, Immunochemistry, 8, 871-874 (1971), which are all incorporated herein by reference. The assay is a simple method for the quantitative determination of antibodies. Microtiter plates coated with antigen are incubated with antiserum followed by an enzyme-labeled preparation of anti-globulin. The enzyme-labeled anti-globulin remaining in the wells after washing and quantitated by addition of a chromogenic substrate, provides a measure of the amount of specific antibodies in serum.
Plasma having a sufficiently high titer of antibody is pooled and fractionated to obtain an immune serum globulin. To this end one may employ any method for obtaining an intravenously injectable immune serum globulin from pooled plasma. For example, one may employ the Cohn fractionation method (referenced hereinabove, which references are incorporated herein by reference thereto) an ammonium sulphate fractionation, polyethylene glycol precipitation or the like. The aforementioned immune serum globulin comprises IgG, usually at least 90% IgG monomer. The material generally also contains other globulins such as IgA, IgM, and the like.
These high titer sera or plasmas are pooled and subjected to the Cohn fractionation method to produce Fraction II [Cohn et al, J. Am. Chem. Soc., 68, 459 (1946) and Oncley, et al, ibid., 71, 541 (1949)].
As mentioned above, the CMV hyperimmune globulin may be intramuscularly or intravenously injectable. The latter material is preferred and may be prepared, for example, according to the method of Tenold, "Intravenously Injectable Immune Serum Globulin", U.S. Ser. No. 295,916, filed Aug. 24, 1981 and/or U.S. Pat. No. 3,903,262 (which are incorporated herein by reference) or any of the methods referred to in the above-identified U.S. patent.
The modified immune serum globulin of U.S. Pat. No. 3,903,262 is adapted for intravenous injection and consists of intact immune serum globulin chains having partly intact interchain disulfide linkages. Each cleaved disulfide linkage is replaced by a pair of alkylated mercapto groups, the cleaved chains remaining united by non-covalent association so that the apparent molecular weight of the modified serum globulin in non-dissociating solvents is essentially the same as unmodified immune serum globulin. The above material is produced by reducing, in a mildly alkaline aqueous solution, immune serum globulin with dithiothreitol or dithioerythritol, alkylating the thus-reduced interchain disulfide groups, and separating the thus-modified globulin from the non-proteinaceous reaction products.
The hyperimmune globulin preparation of this invention can also include maltose as a stabilizer in accordance with the teaching of U.S. Pat. No. 4,186,192. Accordingly, the instant preparation may contain about 1-20% of maltose on a weight to volume basis.
The hyperimmune products of the invention may be manufactured as pharmaceutical preparations, usually aqueous solutions of the hyperimmune serum globulin which may be used for prophylactic and therapeutic purposes.
The pharmaceutical preparation intended for therapeutic use should allow delivery of a therapeutic amount of hyperimmune serum globulin, i.e., that amount necessary for preventive or curative health measures.
EXAMPLES
The invention is demonstrated further by the following illustrative examples.
Assay Method
The ELISA method was essentially the same as that described by Engvall and Perlmann, ibid., and used by Carlsson et al. Inf. Imm., 6 (5) 703-708 (1972) for titration of anti Salmonella immunoglobulins. The method has been previously adapted for microtiter plates Voller et al. Manual of Clinical Immunology, 1976, 506-512, where visual endpoints can be determined with good sensitivity, Poxton, J. Clin. Path., 32, 294-295 (1975), Voller et al, supra.
Round bottomed wells in polystyrene microtiter plates were sensitized by addition of 0.1 ml of CMV antigen in carbonate-bicarbonate buffer, pH 9.5, and incubated at 4° C. for approximately 18 hours. CMV antigen is obtained by infecting MCR5 cells with CMV (strain AD 169) and harvesting the viral antigen according to the procedure described by Forghani et al, "Antibody Assays for Varicella-Zoster Virus:Comparison of Enzyme Neutralization, Immune Adherence, Hemagglutination, and Complement Fixation", in J. Clin. Microbiol. 8:5, 545-552 (1978). Plates were washed once with phosphate buffered saline (PBS) containing 0.05% Tween 20 and 0.2% sodium azide (PBSTA). Five percent Bovine serum albumin (BSA), 0.1 ml was added to each well. The plates were further incubated 4-5 hours at room temperature, followed by one wash. The plates were shaken dry after the final wash. Dilutions of antisera were added to each well (0.1 ml) and incubated overnight at room temperature. Wells were washed three times as before and 0.1 ml of goat anti-human IgG conjugated to alkaline phosphatase (Miles Laboratories, Inc.) was added to each well and incubated 2 hours at room temperature. After again washing the wells, 0.1 ml of a 1.0% (w/v) solution of enzyme substrate, p-nitrophenyl phosphate, (Sigma Chemical Co.) in 10% diethanolamine buffer, pH 8.0, with 0.02% sodium azide and 1 mM Mg Cl 2 was added and incubated for 30 minutes, at room temperature. The reaction was stopped by the addition of 0.05 ml of 3N NaOH to each well. The absorbance was read at 405 nm with a Dynatech model 580 micro ELISA reader. The endpoint was taken to be the highest dilution with an absorbance ≧0.010.
Example 1
Plasma donations obtained from donors were screened for high titer of antibody to cytomegalovirus (CMV) using the ELISA method. Plasma with a CMV antibody titer of 1:60,000 or greater were pooled and fractionated to give an intravenously injectable immune serum globulin (IGIV).
The method of U.S. Pat. No. 3,903,262 was followed. Briefly, Cohn Fraction II paste was prepared from the pooled plasma (400 liters) and was suspended in an aqueous sodium chloride solution, which was warmed and mixed with a solution of dithiothreitol. Iodoacetamide was added to the mixture. Next, the mixture was diafiltered to remove residual reagents. After pH adjustment, the material is sterile filtered.
The so-prepared IGIV exhibited a titer of antibody to cytomegalovirus of about 1:448,352 as measured by ELISA.
Example 2
Prior to clinical trials of any biological product, its biological activity is usually assessed first in an animal model system. In the case of human CMV, however, no such model exists, and for this reason a study was undertaken to evaluate the biological activity of CMV-IGIV by means of a virus neutralization test.
The ability of CMV to infect human cells in culture, resulting in visible cytopathology, permitted evaluation of the neutralizing antibody content of CMV-IGIV by means of a semi-quantitative assay, the plaque reduction neutralization test. The procedure used for these tests was essentially the one reported by Schmidt et al; J. Clin. Microbiol. 4:61, 1976, with slight modifications. The important differences are:
1. MRC-5 cells were used both for the propagation of virus stocks and for the performance of the test.
2. Trypsin was included in the overlay medium, which resulted in increased plaque counts.
The basic methodology is similar to plaque assays employed with other viruses, differing primarily in the incorporation of complement (guinea pig serum), which has been shown to enhance neutralizing antibody titers.
IGIV prepared from non-selected plasma was used as a control.
Using the plasma reduction neutralization test, a comparison was made of the neutralizing antibody titers of matched plasma pools and final product for both CMV-IGIV and control IGIV. Table 1 shows a summary of the results of these tests; the antibody titers are expressed as 50% plaque reduction endpoints, determined from regression lines plotted from the probit of percent plaque reduction versus the log of the reciprocal of the antibody dilutions.
TABLE 1______________________________________Sample Neutralizing ELISAIdentification Product Type Antibody Titer Titer______________________________________Selected Plasma Plasma 1:88 1:96,764PoolHyperimmune CMV-IGIV 1:119 1:448,363GlobulinUnselected Plasma Plasma 1:28 1:11,085Pool No. 1Immune Globulin IGIV 1:32 Not DoneNo. 1Unselected Plasma Plasma 1:41 1:15,677Pool No. 2Immune Globulin IGIV 1:21 1:51,200No. 2Unselected Plasma Plasma 1:14 1:14,311Pool No. 3Immune Globulin IGIV 1:61 1:76,800No. 3Unselected Plasma Plasma 1:17 1:12,800Pool No. 4Immune Globulin IGIV 1:29 1:64,000No. 4______________________________________ The geometric mean neutralizing antibody titer of the unselected plasma pools is 1:23. The geometric mean neutralizing antibody titer of the IGIV lots is 1:33. The geometric mean ELISA titer of the unselected plasma pools is 1:13,357 The geometric mean ELISA titer of the IGIV PR lots is 1:63,135. | Normal plasma from donors who have not been vaccinated with a cytomegalovirus vaccine can be screened for higher than normal titers of naturally occurring antibody to cytomegalovirus. Those plasmas with high titers of such antibody can be pooled and fractionated to give hyperimmune serum globulin. The product may be treated to render it suitable for intravenous injection. Patients with cytomegalovirus infection or at risk to such infection, may receive the present product to raise serum titers of cytomegalovirus antibody. | 0 |
FIELD OF THE INVENTION
[0001] The present invention relates to a heat engine which generates electricity from applied buoyancy force using a thermodynamic vapor cycle, e.g., a low-temperature thermodynamic vapor cycle, to induce density changes of a working fluid within a variable volume mobile device.
BACKGROUND
[0002] Fossil fuel power generation damages the global environment and is not sustainable. However the current alternatives to fossil fuel power generation including zero-emission, renewable power systems available are prohibitively large, conspicuous, and not cost competitive with fossil fuel power generation due to high capital cost of equipment and poor energy efficiency. Existing heat engines offer cost effective power generation options in high temperature large power applications, however in low temperature, low power applications these heat engines suffer from high losses in efficiency and high capital cost per unit of power produced. Current power generation equipment is not viably applicable for the large global reserve of low temperature heat sources. These heat sources include solar thermal as well as the large amounts of waste heat arising from fossil-fuel power generation and other industrial processing. Accordingly, there exists a need to create new methods for generating electrical power from low temperature heat sources efficiently, cost effectively, and scalable for both small and large power applications.
SUMMARY
[0003] In accordance with example embodiments, this invention may offer improved energy conversion efficiency over existing turbomachinery heat engine technologies, and allow cost effective use of low power density, renewable fuel sources. Example embodiments of the present invention may provide a means to generate electrical power from low temperature heat sources. It does not require combustion to operate, and may be used in conjunction with solar thermal, for example, as a zero-emission device. The device may be cost competitive, simple to operate, and rapidly installed, converting any suitable low temperature heat source into a modular and scalable electric power supply which can be used locally as well as in conjunction with large-scale power generation, offering high operational availability. The device combines well-known thermodynamic and fluid dynamic principles with commercially available technologies in a unique and non-obvious manner, leveraging density changes occurring within a thermodynamic cycle to alter buoyancy of the heat engine device within a thermal sink fluid.
[0004] The example device generates useful work using a closed-loop vapor cycle which has been modified to incorporate two primary differences from typical heat engine applications:
1) The increase in cycle pressure on the working fluid is not induced from a compressor or pump driven by an input shaft. In addition, the reduction in cycle pressure is not induced by a turbine powering an output shaft. In this example device, cycle pressure is governed by depth of the heat engine immersed within a thermal sink fluid which has pressure differential. The entire heat engine device transitions between regions of low and high pressure thermal sink fluid, in which thermal sink fluid applies pressure force against the refrigerant working fluid via a piston or bladder within the heat engine to create pressure changes in the cycle. In this cycle, pressure difference between the working fluid and the surrounding thermal sink fluid are minimized which simplifies the design of this heat engine invention, and the absence of both compression and turbine machinery reduces capital cost of the device. 2) The shaft work used to generate power is not derived from the continuous flow of the working fluid. In this example device, there is no flow of working fluid in the cycle. Rather, an external heat source provides thermal energy to the working fluid to induce a constant pressure phase change which generates boundary work in a discrete manner. This boundary work is used to change the volume, and thus density, of the overall heat engine relative to the surrounding thermal sink fluid density, generating buoyant potential energy. The use of discrete phases rather than continuous flow phase changes improves device efficiency at the lower pressure ratios and temperatures often present in waste heat source power conversion, by avoiding flow losses that predominate in turbine devices operating under these operating conditions. In this example device, the shaft work used to generate power is generated through the conversion of this buoyant potential energy to mechanical energy through applied buoyant force which moves the entire heat engine device from high pressure region of the thermal sink fluid to the low pressure region of the thermal sink fluid. In this cycle, the effective weight of the heat engine fully immersed in thermal sink fluid is not constant due to the effect of buoyancy, which allows for net positive conversion of potential energy to mechanical energy across the cycle.
These two differences from typical vapor cycle heat engine may provide significant efficiency and cost advantages over existing heat engines operating in low temperature and low power density applications.
[0007] In accordance with example implementations, a method for generating energy using a thermal cycle is provided, the method including: heating and maintaining the temperature of a first volume of a thermal exchange fluid at a level greater than the highest temperature of the thermal cycle, the heating provided via an external heat source configured to transfer heat to the volume of thermal exchange fluid when the volume of thermal exchange fluid is disposed within an insulated heat reservoir that is stationary with respect to a thermal heat sink; maintaining a temperature of the thermal sink at a temperature lower than the lowest temperature of the thermal cycle, the thermal sink comprising a second volume of the thermal exchange fluid and having a high pressure region and low pressure region, the insulated heat reservoir being disposed in the low pressure region of the thermal sink; circulating the thermal exchange fluid between the low temperature thermal sink and the high temperature stationary heat reservoir; transferring heated heat transfer fluid from the stationary insulated heat reservoir to an insulated thermal tank of a first mobile device disposed in the low pressure region of the thermal sink; after transferring the heated heat transfer fluid to the insulated thermal tank, moving the first mobile device along a defined path to the high pressure region of the thermal sink, the movement of the first mobile device being actuated via at least one of (a) a weight of the first mobile device and (b) a corresponding countermovement of a second mobile device from the high pressure region of the thermal sink to the low pressure region of the thermal sink; after moving the first mobile device to the high pressure region of the thermal sink, transferring at least a portion of the heated heat transfer fluid from the thermal tank of the first mobile device to a heat exchanger disposed in an insulated phase-change tank of the first mobile device, thereby heating a refrigerant disposed in a variable-volume reservoir of the insulated phase-change tank, the heating of the refrigerant causing at least a portion of the refrigerant to change from a liquid phase to a vapor phase, the change of the refrigerant from the liquid phase to the vapor phase causing the volume of the variable-volume reservoir to increase, thereby reducing the density of the first mobile device to provide a buoyant force to cause the first mobile device to move from the high pressure region of the thermal sink to the low pressure region of the thermal sink; generating electrical energy from the movement of the first mobile device from the high pressure region of the thermal sink to the low pressure region of the thermal sink; transferring low temperature heat transfer fluid from the high pressure thermal sink to the thermal tank of the first mobile device prior to the first mobile device reaching the low pressure region of the thermal sink; and after the movement of the first mobile device from the high pressure region of the thermal sink to the low pressure region of the thermal sink, transferring at least a portion of the low temperature heat transfer fluid from the thermal tank of the first mobile device, in addition to some portion of low temperature heat transfer fluid from the thermal sink to the heat exchanger, thereby cooling the refrigerant to cause at least a portion of the refrigerant to change from a vapor phase to a liquid phase, the change of the refrigerant from the vapor phase to the liquid phase causing the volume of the variable-volume reservoir to decrease, thereby increasing the density of the first mobile device to facilitate movement of the first mobile device from the low pressure region of the thermal sink to the high pressure region of the thermal sink after heated heat transfer fluid is again transferred from the insulated heat reservoir into the insulated thermal tank of the first device.
[0008] In accordance with example implementations, a system configured to operate according to a thermal cycle includes: a thermal exchange fluid; a heating mechanism configured to heat and maintain a temperature of a first volume of the thermal exchange fluid at a level greater than the highest temperature of the thermal cycle, the heating mechanism including an external heat source configured to transfer heat to a volume of thermal exchange fluid stored within a stationary insulated heat reservoir; a thermal sink comprising a second volume of the thermal exchange fluid with a pressure differential maintained at a temperature lower than the lowest temperature of the thermal cycle, which encloses the stationary heat reservoir containing high temperature thermal exchange fluid within a low pressure region of the thermal sink, and is configured to allow circulation of thermal exchange fluid between the low temperature thermal sink and the high temperature stationary heat reservoir as part of a closed thermodynamic cycle; a mechanism configured to maintain an orientation of the insulated heat reservoir containing high temperature thermal exchange fluid stationary, with open bottom facing the region of higher pressure of thermal sink; a mechanism configured to limit heat transfer between the high temperature thermal exchange fluid stored in the stationary heat reservoir and the low temperature thermal exchange fluid in the surrounding thermal sink through the open bottom of the stationary heat reservoir; a mobile device configured to move within the volume of thermal sink fluid via a defined linear path through the pressure gradient between the stationary heat reservoir enclosed within the low pressure region, and some defined depth within the higher pressure region determined by the high pressure point of the thermodynamic cycle, the mobile device including an insulated thermal tank configured to carry either, (a) a volume of the high temperature thermal exchange fluid from the stationary insulated heat reservoir in the low pressure region of the thermal sink to the high pressure region in the thermal sink, or (b) a volume of low temperature thermal exchange fluid from the thermal sink in the high pressure region of the thermal sink to the low pressure region in the thermal sink, an insulated phase-change tank of fixed volume which contains a variable volume reservoir capable of minimally restrained volumetric expansion and contraction which acts as a closed boundary between (a) a fixed mass of refrigerant and a heat exchanger configured to transfer heat between a volume of circulating thermal exchange fluid and the fixed mass of refrigerant to induce phase change of the refrigerant between liquid and vapor states, and (b) a volume of low temperature thermal exchange fluid which enters and exits the phase-change tank from the thermal sink with minimal restraint in inverse proportion to the variable volume reservoir expansion and contraction, an insulated regenerator tank which captures and carries a portion of the volume of thermal exchange fluid exiting the heat exchanger within the phase-change tank between the low and high pressure regions of the thermal sink for improved efficiency, a ballast tank which is used to ensure that the mobile device has a net density equal to or greater than the surrounding thermal sink fluid when the refrigerant is in liquid state, while also ensuring that the mobile device has a net density less than the surrounding thermal sink fluid when the refrigerant is in vapor state, a transfer mechanism configured to circulate the high temperature thermal exchange fluid (a) from the stationary heat reservoir into the thermal tank in region of low pressure thermal sink, and then (b) contain high temperature thermal exchange fluid within the thermal tank as it moves from the low pressure region to high pressure region of thermal sink, and then circulate high temperature thermal exchange fluid (c) from the thermal tank into and through the heat exchanger within the phase-change tank to complete a phase change of the refrigerant from liquid to vapor, and (d) lower temperature thermal exchange fluid from the outlet of the heat exchanger to the regenerator tank, a transfer mechanism configured to circulate the low temperature thermal exchange fluid (a) from the thermal sink into the thermal tank in region of high pressure thermal sink, and then (b) contain low temperature thermal exchange fluid within the thermal tank as it moves from the high pressure region to low pressure region of thermal sink, and then circulate low temperature thermal exchange fluid (c) from the thermal tank, in addition to some portion of low temperature heat transfer fluid from the thermal sink into and through the heat exchanger within the phase-change tank to complete a phase change of the refrigerant from vapor to liquid, and (d) higher temperature thermal exchange fluid from the outlet of the heat exchanger to the regenerator tank, and a closed loop flow path which allows thermal exchange fluid to pass freely (a) between the regenerator tank of the mobile device to the low temperature thermal sink, and then (b) from the low temperature thermal sink to the high temperature stationary heat reservoir; a mechanism configured to transmit the buoyant force acting on the mobile device during ascent between region of high pressure thermal sink to the region of low pressure thermal sink to a generator configured to convert motion to electrical power; a mechanism configured to prime the system by moving the mobile device from the low pressure region of thermal sink to the high pressure region of thermal sink through application of either (a) force weight from the ballast tank, or (b) tension force provided by a second mobile device connected in tandem; and a mechanism configured to stop the ascent of the mobile device when the thermal tank is fully enclosed within the stationary heat reservoir while the phase-change and regenerator tanks remain external to the stationary heat reservoir within the low pressure region of the thermal sink.
[0009] The volume of fluid with a pressure differential may be a liquid.
[0010] The system may further include a cable-and-pulley system configured to transmit the buoyant motion of the mobile device to an input of the generator.
[0011] The tandem system mobile device may be a first mobile device, the system further comprising a second mobile device, wherein movement of the first mobile device in a first direction along the cable-and-pulley system causes movement of the second mobile device in a second direction along the cable-and-pulley system, the first second direction being opposite the first direction.
[0012] The generator may be a linear generator coupled to the mobile device.
[0013] The linear generator may surround the mobile device via a thermal sink enclosure.
[0014] The buoyant motion of the mobile device may be transmitted to the generator via at least one of a propeller and a turbine.
[0015] The generator may be disposed in the mobile device.
[0016] The generator may be connected to a pump and the generator is powered by the movement of fluid passing over the mobile device as the mobile device moves within the thermal sink.
[0017] The generator may be configured to translate relative movement between the mobile device and any stationary position into electromagnetic power generation.
[0018] The mobile device may not contain a regenerator tank, whereby the thermal exchange fluid is transferred directly from the outlet of the heat exchanger to the thermal sink.
[0019] The heat exchanger may include thermal exchange fluid contained within a tube enclosed by refrigerant.
[0020] The heat exchanger may include refrigerant contained within the variable volume reservoir surrounded by thermal exchange fluid.
[0021] The heat exchanger may contain refrigerant contained inside a tube within the variable volume reservoir surrounded by thermal exchange fluid.
[0022] The pressure differential within the thermal sink may be generated through the application of gravity in a vertical configuration of the system.
[0023] The pressure differential within the thermal sink may be generated though application of centrifugal force generated by rotating a closed volume of the thermal sink in a horizontal configuration of the system.
[0024] The transfer of thermal exchange fluid within the mobile device may be generated via at least one circulation pump contained within the mobile device.
[0025] The transfer of thermal exchange fluid within the mobile device may be generated via at least one plunger acting against at least one container wall of the thermal sink.
[0026] Multiple mobile devices may be operated together to generate a collective electrical power.
[0027] The ballast tank may be used to facilitate cold-start capability of a tandem system by ensuring the first mobile device has a net density less than the surrounding thermal sink fluid with its refrigerant is in liquid state, but maintains greater net density than the second mobile device with its refrigerant in vapor state.
[0028] In accordance with example implementations, example devices may be operated at low temperatures, slow speeds, and/or very low delta pressures, which reduces the cost of heat engine machinery and improves cycle efficiency by minimizing thermodynamic cycle irreversibilities which predominate in low temperature and low flow applications with direct coupling between circulating working fluid and power generation machinery. The relatively simple design of the example device may provide reduced capital cost of heat engine machinery and faster installation, permitting cost effective scalable application to both low and high power applications, for example.
[0029] In accordance with example implementations, example devices are hybrid and may convert any suitable type external heat source to useable work, and may offer advantages over existing turbomachinery heat engine devices when used in conjunction with low temperature heat, due to its higher efficiency of energy conversion. Any suitable thermal exchange fluid may be used to transfer heat from any external heat source to the high temperature reservoir used by the device. The device is capable, in at least some implementations, of economically utilizing solar thermal energy in a zero, or substantially zero, particulate/noise/waste emission, non-combustion application, operating with no substantial impact on the environment with water comprising both the thermal exchange and thermal sink fluid in some examples.
[0030] In accordance with example implementations, example devices may assume a functional form that allows for a very small surface footprint, while providing for a large operational volume hidden either below the surface of a body of water or below ground level within reservoirs or casings filled with fluid. This small visible size provides improved visual appeal for the example device over existing environmentally-friendly power generation equipment such as photovoltaic solar panels and wind turbines, which all require large surface area footprints to generate sufficient power from low power density energy sources. In addition, the slow operational speed in some implementations, e.g., the example device of FIG. 1 and FIG. 2 , combined with minimal machinery which operates below the surface allows for a device that is effectively silent. Silent or inaudible operation and small visible footprint may enable improved public perception, and may permit symbiotic operation among adjoining residential populations. Moreover, the small visible footprint and lack of appreciable noise may allow the device to comply with zoning regulations and/or local or community rules or residential codes.
[0031] In accordance with example implementations, example devices may integrate with currently available, existing technologies which allow the generation of electrical power from mechanical energy conversion. The example device may easily integrate with most existing power generation equipment, and may also be operated in conjunction with large utility power plants converting a portion of waste heat, which is currently exhausted to environmental heat sinks, into electrical power in a combined cycle application.
[0032] Further features and aspects of example embodiments of the present invention are described in more detail below with reference to the appended Figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] FIG. 1A shows an example heat engine device having a vertical configuration.
[0034] FIG. 1B shows a detail view of a mobile device of the heat engine device illustrated in FIG. 1A .
[0035] FIG. 1C shows a detail view of a heat source mechanism of the heat engine device illustrated in FIG. 1A .
[0036] FIG. 2 depicts a system view of the heat engine of FIG. 1A working in tandem in vertical configuration within an open body of water
[0037] FIG. 3 shows the system operation of the heat engine device of FIGS. 1A and 2 aligned with a pressure-enthalpy diagram of the vapor cycle
[0038] FIG. 4 shows the system operation of the heat engine device of FIGS. 1A and 2 aligned with a temperature-entropy diagram of the vapor cycle.
[0039] FIG. 5 shows a hierarchal chart of example implementations.
DETAILED DESCRIPTION
[0040] The term “Mobile Pod” is used interchangeably with “Mobile Device” herein to mean the enclosure of the portion of the device containing the refrigerant working fluid which changes density and volume and transitions alternately between regions of high and low pressure within the thermal sink to produce work to generate electrical power
[0041] The term “Thermal Exchange Fluid” will be abbreviated as (TEF), and is used herein to mean the fluid that comprises the thermal sink within which the mobile pod operates, used to either add or remove heat from the refrigerant working fluid to induce phase change.
[0042] The term “Thermal Tank” is used herein to mean an insulated tank within the mobile pod which contains either high or low temperature TEF.
[0043] The term “Phase-change Tank” is used herein to mean an insulated fixed volume tank containing a variable volume reservoir within the mobile pod which contains a heat exchanger and a refrigerant.
[0044] The term “Heat Reservoir” is used herein to mean an insulated reservoir of high temperature TEF which is held stationary within the thermal sink and maintained at high temperature through interface with an external heat source
[0045] The term “Density Engine” is used herein to describe the heat engine device as a whole, which converts thermal energy to potential energy to kinetic energy to electrical energy using: one or more mobile pods interfacing with an electrical generator, one or more stationary heat reservoirs interfacing with an external heat source, and a volume of thermal sink fluid with pressure differential which encloses all mobile pods, through full range of travel, and all stationary heat reservoirs.
[0046] The following description describes, inter alia, operation corresponding to a density engine 45 as illustrated in FIG. 1A , for example, the vertical configuration density engine 45 in an open water environment with a cable pulley arrangement of two mobile pods 28 and 29 operating in tandem as shown in FIG. 2 , the following stationary positions align to the thermal cycle as shown in FIG. 3 and FIG. 4 , which identify the cycle state points on both pressure/enthalpy and temperature/entropy diagrams respectively. Stations A to D are described below.
[0047] Station A: Mobile device 1 is stationary near surface in thermal sink low pressure region 22 at lowest pressure in cycle, refrigerant 4 is cold liquid within the phase-change tank 3 , with variable volume reservoir 5 contracted to minimum volume, and the density of the mobile device 1 is equal to the density of the thermal sink 7 while thermal tank 2 of the mobile pod 28 is held within the stationary heat reservoir 19 and filled with high temperature TEF 20 .
[0048] Station B: Mobile device 1 is stationary at depth in thermal sink high pressure region 23 at highest pressure in cycle, refrigerant 4 is cold liquid within the phase-change tank 3 , with variable volume reservoir 5 contracted to minimum volume, and the density of the mobile device 1 is equal to thermal sink 7 density while thermal tank 2 is within the thermal sink 7 and contains high temperature TEF 20 .
[0049] Station C: Mobile device 1 is stationary at depth in thermal sink high pressure region 23 at highest pressure in cycle, refrigerant 4 is hot vapor within the phase-change tank 3 , with variable volume reservoir 5 expanded to a larger volume, and the density of mobile device 1 is less than the density of the thermal sink 7 , while thermal tank 2 is within the thermal sink 7 and filled with low temperature TEF 24 .
[0050] Station D: Mobile device 1 is stationary near surface in thermal sink low pressure region 22 at lowest pressure in cycle, refrigerant 4 is hot vapor within the phase-change tank 3 , with variable volume reservoir 5 expanded to maximum volume, and the density of mobile device 1 is less than the density of thermal sink 7 while thermal tank 2 is held within the stationary heat reservoir 19 and contains low temperature TEF 24 .
[0051] FIG. 1B shows detail of a mobile device 1 , which corresponds to the same structure of both a first pod 28 and a second pod 29 as illustrated in FIG. 2 . FIG. 1C shows a heat source mechanism 55 . Heat source mechanism 55 is the same as the heat source mechanism 57 shown in FIG. 2 , except that the heat source 57 in FIG. 2 has two high temperature reservoirs 19 attached to external heat source 18 . FIG. 1A shows an overall view of the density engine 45 which includes both mobile device 1 and heat source mechanism 55 , as shown in FIGS. 1B and 1C respectively, aligned in assembly view.
[0052] Referring to FIG. 2 , for the illustrated example identifies how the tandem mobile pods 28 and 29 transition between these station points which allows the density engine 45 device to convert thermal energy to electrical power. The operation is described from the view of first pod 28 , however it should be noted that both first pod 28 and second pod 29 complete the cycle in the same manner but are offset by two station points at all times.
[0053] The density engine 45 , as shown in FIGS. 1A and 2 , includes a thermal sink 7 which is a large volume of low temperature TEF 24 , an external heat source 18 and electrical generator 30 , a stationary insulated heat reservoir 19 located within the thermal sink 7 which contains high temperature TEF 20 , and two mobile pods 28 and 29 , which contain refrigerant 4 working fluid, connected together via cable 26 via pulleys 25 and 27 .
[0054] The first pod 28 is connected to the second pod 29 via a cable 26 which extends around an upper pulley 25 and a lower pulley 27 allowing free movement of each pod within a thermal sink 7 between a thermal sink low pressure region 22 and a thermal sink high pressure region 23 .
[0055] Cable 26 , upper pulley 25 and lower pulley 27 transfer force between the first pod 28 , the second pod 29 , and the electrical generator 30 which may have an input shaft coupled to the upper pulley 25 . Thus, rotation of the pulley due to the action of the pods 28 and 29 pulling the cable 26 coupled to the pulley 25 causes the input shaft to rotate, thereby converting the mechanical movement of the pods 28 and 29 into electrical energy. Although the generator 30 is driven via rotation of the upper pulley 25 , it should be understood that the upper pulley 25 and/or the lower pulley 27 may be coupled to one or more generators to generate electricity. In the illustrated example, the generator is turned in alternating rotational directions as the mobile pods 28 and 29 rise, respectively.
[0056] Cable 26 , upper pulley 25 , and lower pulley 27 operate such that the pods to not contact each other as they travel between thermal sink low pressure region 22 and thermal sink high pressure region 23 .
[0057] Cable 26 , upper pulley 25 , and lower pulley 27 operate such that as the first pod 28 moves from Station A to Station B the second pod 29 moves from Station C to Station D at the same time and rate. It should be understood, however, that in some example implementations, one or more pods may be configured to move at different times and/or rates.
[0058] Cable 26 may have one or more stops to prevent the pods from contacting the pulleys 25 and 27 .
[0059] Mobile device 1 has ballast tank 16 to ensure neutral buoyancy from Station A through Station B. It should be understood, however, that in some other example implementations, one or more mobile devices 1 may be ballasted so that there is negative buoyancy from Station A through Station B due to greater pod density than surrounding thermal sink 7 fluid density.
[0060] TEF circulation pump 11 is powered by via external power transmitted through cable 26 , although any suitable power transfer mechanism may be implemented.
[0061] Stationary heat reservoir 19 is connected to the external heat source 18 through insulated piping which maintains a constant temperature of the high temperature TEF 20 within the reservoir.
[0062] Summary of 1 st stage of operation: Starting at Station A for first pod 28 , the descent from Station A to Station B primes the density engine 45 through application of tensile force from the ascent of the second pod 29 transmitted through cable 26 and lower pulley 27 to drag first pod 28 from surface in thermal sink low pressure region 22 to deepest depth in thermal sink high pressure region 23 . The first pod 28 has neutral buoyancy as it travels from Station A to Station B and is effectively weightless which reduces the force acting on second pod 29 to only drag force by first pod 28 .
[0063] Details of 1 st Stage of Operation:
[0064] The first pod 28 at Station A has its thermal tank 2 fully immersed within the stationary heat reservoir 19 , with the thermal tank 2 completely filled with high temperature TEF 20 .
[0065] The first pod 28 at Station A has its phase-change tank 3 fully immersed within thermal sink 7 .
[0066] The first pod 28 at Station A has its variable volume reservoir 5 contracted to minimum volume and filled with refrigerant 4 in liquid state isolated from thermal sink 7 fluid by the phase-change tank seal 6 .
[0067] The first pod 28 at Station A is located in the thermal sink low pressure region 22 .
[0068] The first pod 28 at Station A has neutral buoyancy and is effectively weightless in the thermal sink low pressure region 22 .
[0069] For the first pod 28 at Station A, the refrigerant 4 pressure and low temperature TEF 24 pressure equal the pressure in thermal sink low pressure region 22 .
[0070] The first pod 28 is pulled from Station A to Station B by application of tensile force from the ascent of the second pod 29 transmitted through cable 26 and lower pulley 27 as it concurrently ascends from Station C to Station D.
[0071] As the first pod 28 travels from Station A to Station B, the phase-change tank seal 6 remains stationary due to the nearly incompressible nature of both the refrigerant 4 and the surrounding thermal sink 7 fluid in liquid state, which do not change volume despite the pressure increase as the first pod 28 moves from the thermal sink low pressure region 22 to the thermal sink high pressure region 23 .
[0072] No pressure differential exists across the phase-change seal 6 or the thermal sink flow access point 17 on the phase-change tank 3 .
[0073] As the first pod 28 travels from Station A to Station B, its overall density remains constant and equal to the low temperature TEF 24 density, and therefore has approximately neutral buoyancy both at Station A and Station B locations.
[0074] As the first pod 28 travels from Station A to Station B, its remains filled with high temperature TEF 20 . The thermal tank 2 is insulated to minimize heat loss from the high temperature TEF 20 to the thermal sink 7 while the first pod 28 travels from Station A to Station B.
[0075] Summary of 2 nd stage of operation: Once first pod 28 reaches Station B the pod is held stationary as a refrigerant 4 phase change occurs between Station B and Station C. The high temperature TEF 20 is circulated from the thermal tank 2 to the refrigerant 4 , transferring heat to the refrigerant 4 , by means of a heat exchanger 13 , boiling the liquid refrigerant 4 to vapor. The refrigerant 4 expands during phase change within the variable volume reservoir 5 and increases the volume of first pod 28 . This requires an expenditure of work done on the system, by expelling thermal sink 7 fluid from the phase-change tank 3 , and first pod 28 density becomes lower than the surrounding thermal sink 7 fluid which creates positive buoyant force. TEF exiting first pod 28 through the TEF regenerator outlet 15 at lower temperature is dumped to thermal sink 7 , and low temperature TEF 24 from the thermal sink 7 replaces the high temperature TEF 20 in the first pod 28 thermal tank 2 .
[0076] Details of 2 nd Stage of Operation:
[0077] The first pod 28 at Station B is located in the thermal sink high pressure region 23 .
[0078] As the first pod 28 arrives and becomes stationary at Station B, TEF circulation pump 11 begins pumping high temperature TEF 20 from top of the thermal tank 2 via the thermal tank outlet 10 into the heat exchanger 13 .
[0079] As high temperature TEF 20 is pumped from the thermal tank 2 , a negative delta pressure acts on the thermal tank inlet and check valve 8 which opens the check valve and siphons an equivalent volume of low temperature TEF 24 from the thermal sink 7 into the bottom of the thermal tank 2 replacing the high temperature TEF 20 which was stored in the thermal tank 2 .
[0080] TEF circulation pump 11 transfers high temperature TEF 20 from the heat exchanger 13 , which transfers heat into the refrigerant 4 to complete a phase change of the refrigerant 4 at constant pressure and temperature from liquid at Station B to fully saturated vapor state at Station C.
[0081] Thermal tank 2 volume is sized to ensure sufficient high temperature TEF 20 is available to complete phase transition of the refrigerant 4 from liquid to fully saturated vapor state.
[0082] TEF pumped by the TEF circulation pump 11 through the heat exchanger 13 enters the regenerator tank 9 , pushing an equivalent volume of TEF out of the regenerator tank outlet 15 and into thermal sink 7 .
[0083] As the refrigerant 4 completes the phase change from liquid to fully saturated vapor, all high temperature TEF 20 has been removed from the thermal tank 2 and replaced with low temperature TEF 24 from the thermal sink 7 .
[0084] Regenerator tank 9 is used to improve efficiency of the cycle by ensuring that waste heat remaining in the TEF following circulation through the heat exchanger 13 between Station B and Station C cycle transition, which occurs in thermal sink high pressure region 23 , is transferred through the heat exchanger outlet and regenerator tank inlet 14 and stored in the regenerator tank 9 . This TEF with remaining waste heat is then carried by the first pod 28 during ascent from Station C to Station D, and released through the regenerator outlet 15 between Station D and Station A cycle transition for heat recovery within the stationary heat reservoir 19 .
[0085] As the refrigerant 4 completes the phase change from liquid to fully saturated vapor it increases temperature and pressure within the variable volume reservoir 5 which moves the phase-change tank seal 6 and pushes surrounding thermal sink 7 fluid out of the phase-change tank 3 , through the thermal sink flow access point 17 , and into the thermal sink 7 located in the thermal sink high pressure region 23 .
[0086] As the refrigerant 4 of the first pod 28 completes the phase change from liquid at Station B to fully saturated vapor at Station C, variable volume reservoir 5 is expanded with the high temperature, low density refrigerant 4 vapor, and the overall mobile device 1 density is lower relative to the surrounding thermal sink 7 fluid density, which creates a positive buoyancy force on the first pod 28 at Station C acting in the direction from thermal sink high pressure region 23 to thermal sink low pressure region 22 .
[0087] Summary of 3 rd stage of operation: Once the refrigerant 4 phase change to vapor is complete at Station C, first pod 28 ascends from Station C to Station D due to positive buoyancy force which generates mechanical work by the density engine 45 through conversion of buoyant potential energy to buoyant kinetic energy. This work is used to both generate electricity and prime second pod 29 . During the ascent from thermal sink high pressure region 23 at Station C to thermal sink low pressure region 22 at Station D, the variable volume reservoir 5 within first pod 28 steadily moves the phase-change tank seal 6 and expands volume against the reducing back-pressure of the surrounding thermal sink 7 , allowing thermal sink 7 fluid to be continuously expelled from the phase-change tank 3 , steadily increasing the positive buoyant force acting on first pod 28 as it ascends, to a maximum force at Station D.
[0088] Details of the 3 rd Stage of Operation:
[0089] The first pod 28 at Station C has its thermal tank 2 fully immersed within the thermal sink high pressure region 23 , with the thermal tank 2 completely filled with low temperature TEF 24 .
[0090] The first pod 28 at Station C has variable volume reservoir 5 filled with refrigerant 4 in vapor state isolated from the surrounding thermal sink 7 fluid by the phase-change tank seal 6 .
[0091] The first pod 28 at Station C has less density than the surrounding thermal sink 7 fluid within thermal sink high pressure region 23 creating a positive buoyancy force acting on the first pod 28 in a direction from the thermal sink high pressure region 23 towards the thermal sink low pressure region 22 .
[0092] The buoyancy force acting on the first pod 28 transfers through cable 26 and lower pulley 27 and pulls the second pod 29 in a direction from the thermal sink low pressure region 22 at Station A towards the thermal sink high pressure region 23 at Station B.
[0093] For the first pod 28 at Station C, the refrigerant 4 pressure and low temperature TEF 24 pressure equal the pressure in thermal sink high pressure region 23 .
[0094] The first pod 28 travels from Station C to Station D, concurrently pulling the second pod 29 from Station A to Station B via cable 26 .
[0095] During this phase of the cycle, power is generated by the first pod 28 transmitting buoyancy force via cable 26 turning the upper pulley 25 which operates the electrical generator 30 .
[0096] As the first pod 28 travels from Station C to Station D, phase-change tank seal 6 moves unrestricted within the phase-change tank 3 , with its resting location dependent on equilibrium pressure between the refrigerant 4 in vapor state within the variable volume reservoir 5 and the surrounding thermal sink 7 fluid.
[0097] As the first pod 28 travels from thermal sink high pressure region 23 at Station C to thermal sink low pressure region at Station D, back-pressure exerted on the phase-change tank seal 6 by the surrounding thermal sink 7 fluid steadily reduces and allows the hot refrigerant 4 vapor within the variable volume reservoir 5 to expand further.
[0098] As the first pod 28 travels from Station C to Station D, its expanding variable volume reservoir 5 steadily pushes more thermal sink 7 fluid out of the phase-change tank 3 through the thermal sink flow access point 17 , continuously decreasing the density of first pod 28 while increasing positive buoyancy force to a maximum in thermal sink low pressure region 22 at Station A.
[0099] Once first pod 28 arrives at Station D, the variable volume reservoir 5 is fully expanded with refrigerant 4 vapor at equilibrium pressure with the surrounding thermal sink low pressure region 22 , leaving no thermal sink 7 fluid remaining within the phase-change tank 3 .
[0100] The first pod 28 is guided into the stationary heat reservoir 19 by cable 26 such that first pod 28 thermal tank 2 moves through stationary heat reservoir thermal barrier curtain 21 until the thermal tank inlet and check valve 8 are within the stationary heat reservoir 19 with access to the high temperature TEF 20 .
[0101] Stationary heat reservoir thermal barrier curtain 21 acts as a thermal barrier to limit transfer of high temperature TEF 20 into the thermal sink low pressure region 22 , and also limits transfer of thermal sink 7 fluid from the thermal sink low pressure region 22 into the stationary heat reservoir 19 .
[0102] Summary of 4 th stage of operation: Once first pod 28 reaches Station D the pod is held stationary as a refrigerant 4 phase change occurs between Station D and Station A. The low temperature TEF 24 is circulated from both the thermal tank 2 , and from the thermal sink 7 to the refrigerant 4 , removing heat from the refrigerant 4 , by means of a heat exchanger 13 , condensing the superheated vapor refrigerant 4 to fully liquid. The refrigerant 4 contracts during phase change increasing density within the variable volume reservoir 5 , decreasing the volume of first pod 28 . The system expends work on the density engine 45 , by filling the phase-change tank 3 with thermal sink 7 fluid. The first pod 28 density becomes equal to the surrounding thermal sink 7 fluid which creates a neutral buoyant force which makes the mobile device 1 effectively weightless. TEF exiting first pod 28 through the TEF regenerator outlet 15 at lower temperature is dumped to thermal sink 7 , and high temperature TEF 20 from the stationary heat reservoir 19 replaces the low temperature TEF 24 in the first pod 28 thermal tank 2 .
[0103] Details of 4 th Stage of Operation:
[0104] The first pod 28 at Station D is located in the thermal sink low pressure region 22 .
[0105] As the first pod 28 arrives and becomes stationary at Station D, TEF circulation pump 11 begins pumping low temperature TEF 24 from top of the thermal tank 2 via the thermal tank outlet 10 into the heat exchanger 13 .
[0106] As low temperature TEF 24 is pumped from the thermal tank 2 , a negative delta pressure acts on the thermal tank inlet and check valve 8 which opens the check valve and siphons an equivalent volume of high temperature TEF 24 from the stationary heat reservoir 19 into the bottom of the thermal tank 2 replacing the low temperature TEF 24 which was stored in the thermal tank 2 .
[0107] TEF circulation pump 11 transfers low temperature TEF 24 to the heat exchanger 13 , which removes heat from the refrigerant 4 to begin a phase change of the refrigerant 4 at constant pressure and temperature from superheated vapor at Station D to fully liquid state at Station A.
[0108] TEF circulation pump 11 continues to transfer low temperature TEF 24 from the thermal tank 2 until the entire volume of low temperature TEF 24 has been replaced by high temperature TEF 20 from the stationary heat reservoir 19 . At this time the diverter valve 12 changes the TEF circulation pump 11 low temperature TEF 24 inlet source from the thermal tank 2 to the thermal sink 7 . TEF circulation pump 11 continues to transfer low temperature TEF 24 from the thermal sink 7 until the phase transition of the refrigerant 4 from superheated vapor to fully liquid state is complete.
[0109] TEF pumped by the TEF circulation pump 11 through the heat exchanger 13 enters the regenerator tank 9 , pushing an equivalent volume of TEF out of the regenerator tank outlet 15 and into bottom of the stationary heat reservoir 19 .
[0110] As the refrigerant 4 completes the phase change from superheated vapor to fully liquid state it decreases temperature and pressure within the variable volume reservoir 5 which allows the phase-change tank seal 6 to be moved by the surrounding thermal sink 7 fluid entering the phase-change tank 3 through the thermal sink flow access point 17 from the thermal sink low pressure region 22 .
[0111] As the first pod 28 refrigerant 4 completes the phase change from superheated vapor at Station D to fully liquid state at Station A, variable volume reservoir 5 is fully contracted containing the low temperature, high density refrigerant 4 liquid, and the overall mobile device 1 density with ballast tank 16 equals the surrounding thermal sink 7 fluid density, which creates neutral buoyant force which makes the mobile device 1 effectively weightless at Station A.
[0112] The cycle repeats for mobile pods 28 and 29 as long as TEF within the stationary heat reservoir 19 continues to be maintained at highest cycle temperature, TEF within the thermal sink 7 continues to be maintained at the lowest cycle temperature, and the TEF continues to be circulated through the heat exchanger 13 between both Stations D and A, and Stations B and C.
[0113] As an example, in the vertical configuration described with regard to FIG. 2 , an optimum refrigerant available with open domain data tables is R236EA which may allow operational depth range between 25 and 615 feet within a thermal sink which is ocean water at 12 deg C. The mobile pod travel speed may be limited to approximately 1 foot per second to minimize drag force, and cycle completion for each pod may take over 20 minutes. A single pod sized approximately 3 feet in diameter by 40 feet in length, containing approximately 18 gallons of R236EA refrigerant, operating under these conditions may generate up to 170 kW-Hr/day of electrical power utilizing approximately 50% duty cycle. Approximately 300 tandem pairs of these mobile pods could operate together as a 100 MW power-plant assuming a footprint of less than ¼acre for all heat engine machinery. External heat source temperature required for the refrigerant phase transition is, e.g., 120 deg C, just below the boiling point of ocean water at the operational depth range referenced above. This external heat source temperature may be easily achievable using existing solar thermal hot water panels as well as most industrial or power generation waste heat sources.
[0114] In the example implementations, the size of the mobile pods and volume of refrigerant contained directly correlates to the amount of electrical power generated. Larger pod sizes may be used for large power generation applications with access to large external heat sources, operating within open volumes of thermal sink fluid. Smaller pod sizes may be used in small scale building, household, or mobile applications with limited accessibility to smaller external heat sources, operating within closed volumes of thermal sink fluid. Capital and operational cost factors would determine the optimum application of either large numbers of small pods operating together, or a fewer number of large pods acting independently.
[0115] In some example implementations, the pod arrangement may be configured to drive a linear generator. Each pod may act independently and in this case the pod may be ballasted to allow both negative and positive buoyancy force to drive power generation either ascending or descending or both directions. Such configuration may be used, e.g., in closed thermal sink volume applications like a drilled well with casing. In these closed thermal sink applications, it may be advantageous for the TEF to be salt brine, coolant, or oil instead of ocean water, to increase density and boiling point of the thermal sink fluid which may improve device efficiency. In addition, these smaller pod size applications may facilitate use of a mechanical plunger instead of electrical circulation pump to circulate the TEF to the refrigerant heat exchanger.
[0116] In some example implementations, for instance if device was used to generate electrical power in a mobile application using waste engine heat in the coolant or exhaust, multiple smaller tubes which each contain a mobile pod and thermal sink fluid may be grouped around a central inner axle similar to wheel spokes in a horizontal axis of rotation. These tubes may be filled with engine coolant TEF and act as both radiator and fly-wheel, utilizing the force of air-flow or water-flow acting against the moving vehicle to rotate the thermal sink tubes to both generate a pressure differential within the thermal sink fluid, and cool the thermal sink fluid to surrounding ambient temperature. In this configuration, the mobile pods would generate useful work as they transitioned between Station C on the outer rim of the wheel, towards Station D located on the inner axle due to positive buoyant force. The hot TEF coolant from the vehicle engine would enter the heat reservoir held stationary relative to each rotating tube within the inner axle, and then be carried within each of the mobile pods to the outer rim of the wheel assembly. Upon exiting the pods at the outer rim, it would be cooled and circulated back to the vehicle engine.
[0117] Referring to FIG. 5 , the example implementations of FIGS. 1 to 4 are selected from among many implementations. FIG. 5 shows some example variations in system orientation 100 , pressurization method 105 , pod configuration 110 , operational volume 115 , and system application 120 .
[0118] The two system orientations shown in FIG. 5 are a vertical configuration 130 (e.g., the system shown in FIGS. 1 to 4 ) and a horizontal configuration 170 .
[0119] As shown at 131 , an example pressurization method associated with the vertical configuration 130 is gravitational force pressure differential (e.g., where a TEF is stationary). For this pressurization method 131 , two example density engine configurations, shown at 132 and 133 respectively, are (a) paired pods with pulley(s)/cable(s)/electrical generator system and (b) one or more pods, e.g., a single individual pod, coupled to a linear generator.
[0120] In connection with, for example, density engine configuration 133 , some example operational volumes, shown at 134 and 135 respectively, are (a) open volume TEF (e.g., ocean, lake, reservoir, atmosphere) and (b) closed volume thermal exchange (e.g., vertical closed columns such as tubes contained within skyscrapers or in-ground casings).
[0121] Example system applications of the open water thermal exchange 134 may include, for example, water-based power applications (e.g., steam electric plants, hydroelectric plants, offshore platforms), as shown at 136 .
[0122] Example system applications of the closed-volume thermal exchange 135 may include, for example, land-based power applications (e.g., industrial power, building power, residential power), as shown at 137 .
[0123] As shown at 171 , an example pressurization method associated with the horizontal configuration 170 is centrifugal force pressure differential (e.g., rotating TEF). For this pressurization method 171 , and density engine configuration, shown at 172 , includes, for example, one or more pods, e.g., a single individual pod, coupled to a generator, e.g., a linear generator.
[0124] In connection with, for example, density engine configuration 172 , a example operational volume, shown at 174 , includes, for example, closed volume thermal exchange (e.g., a rotating tube configuration).
[0125] Example system applications of the open water thermal exchange 174 may include, for example, mobile power generation (e.g., for trucks, cars, trains, ships), as shown at 176 . For example, the fluid tubes may be attraction for rotation by force of movement by the vehicle (e.g., a pelton wheel bucket at end of each tube driven by air or water force acting on vehicle as it moves).
[0126] Accordingly, it should be readily apparent that the thermal cycle and fundamental principles of operation described herein may be applied to vertical configurations, horizontal configurations, slanted configurations, or any other suitable configurations. The mobile device or heat exchange apparatus may the same for, e.g., both the paired and individual vertical configurations, which may operate below the surface or above the surface, and may advantageously use salt water or brine as a TEF. The density engine machinery may be different for the horizontal configuration to allow for a smaller size to be used, for example, in mobile applications which would capture waste heat from the engine. In addition, the horizontal application may use the coolant from the engine as the TEF instead of water, and the means by which the device is attached to the electrical generator would more likely be linear generators rather than cable and pulley arrangement. In the horizontal configuration, the pressure differential may be self-generated using a mechanism to spin the horizontal thermal sink tubes and pods.
[0127] It should be understood that any pumping mechanism or other operational parameters of the example systems and implementations may be controlled by any suitable control mechanism, e.g., digital and/or analog control systems, and/or mechanical switching mechanisms, which may, for example, function automatically.
[0128] In accordance with example embodiments, the temperature and pressure states of the vapor cycle utilized by the density engine may be determined by the following factors:
[0129] The highest temperature of the heat source and the lowest temperature of the thermal sink fluid.
[0130] The density of the thermal sink fluid and the pressure gradient within this thermal sink fluid; the pressure gradient is derived from gravitational force in vertical configurations, and pressure ratio of cycle is directly correlated to the depth of descent of mobile pod. However in horizontal configurations, the pressure gradient may be generated using centrifugal force derived from rotating the thermal sink fluid around an axis, which allows optimization of the pressure ratio of cycle by controlling both rotational speed as well as the depth of descent of mobile pod.
[0131] The boiling point of the TEF at the lowest pressure in the cycle; the TEF which is used to transfer heat to the refrigerant is the same fluid as the thermal sink fluid since this fluid flows freely in a closed loop from heat reservoir through the device heat exchanger to the thermal sink. TEF remains in liquid state at all points in cycle. This requires that the boiling point of the TEF at the lowest pressure in cycle remains higher than the highest temperature point of the cycle. If fresh water is used as the TEF, peak temperature of the cycle is limited to below 100 deg C, assuming the mobile pods were allowed to return to surface of thermal sink reservoir at ambient pressure. This maximum cycle temperature can be increased by limiting the maximum ascent depth of the mobile pods to increase minimum pressure in the cycle, which serves to increase the boiling point of the TEF. There is a trade-off between limiting ascent depth versus accessibility to the high temperature stationary reservoir for the mobile pod at these increased depths. The external heat source needs to be circulated to the high temperature stationary reservoir for the mobile pods at depth, and the increased circulation distance has adverse effects on both thermal and flow losses. Increased cycle temperature can also be achieved through the use of alternative TEF mediums including salt water, brine, coolant, or oil based TEFs which have higher boiling points than fresh water.
[0132] The refrigerant type chosen as the working fluid in the cycle; the heat engine device may operate at greater efficiencies by increasing the distance traveled by the mobile pod during the ascent portion of the cycle, and although a variety of high temperature refrigerants may be used for example implementations of the device, the primary selection criteria is maximization of range of mobile pod travel during ascent. The refrigerant needs to remain in stable liquid state at the lowest pressure and lowest temperature in cycle as close as possible to the surface of thermal sink fluid. The refrigerant should be capable of changing phase from liquid to gas at the greatest possible depth of thermal sink fluid at the maximum heat source temperature, without exceeding the critical point pressure of the chosen refrigerant. It should be understood that specific refrigerant composition may be formulated to, for example, optimize device efficiency.
[0133] Although the present application describes particular examples and implementations, it should be understood that the present invention is not limited to those examples and implementations. Moreover, the features of the particular examples and implementations may be used in any combination. The present invention therefore includes variations from the various examples and implementations described herein, as will be apparent to one of skill in the art. | Systems and methods to convert low temperature solar thermal or waste heat sources for electric power generation, by integrating available technologies with a unique, efficient combined cycle. The device consists of mobile pods immersed within a thermal sink fluid reservoir. A vapor cycle converts thermal energy to buoyant potential energy by inducing density and volume changes of the mobile pods through discrete phase changes of a refrigerant working fluid. Buoyant potential energy is then converted to electrical power through motion of the entire pod within a thermal sink pressure gradient. | 8 |
FIELD OF THE INVENTION
This invention relates to a method of managing documents in an information processing system and more particularly, to a method of rapidly identifying documents having the same attributes in a shared library.
BACKGROUND OF THE INVENTION
The electronic office has resulted in the grouping of documents into relationships intended to aid in electronically storing, searching, and retrieving the documents. Use of document libraries represent one technique for meeting this need. As currently implemented, these document libraries offer functions analogous to manual filing and retrieving of paper documents, but in a far less cumbersome manner. One prior art structure which meets the need for electronically storing. Searching and retrieving documents is the Document Interchange Architecture (DIA) which is part of an office system marketed by the International Business Machines Corporation. The DIA document structure provides a set of descriptors for each document filed in a library. These descriptors are placed in document profiles and are filed with the documents. The document profiles contain parameters identifying the contents of the documents, such as the name under which it is filed, the authors, the subject it covers, and the date it was filed in the document library.
The document profiles are used in searching for documents in the document library. For example, a user can ask for all documents about a particular subject, by a certain author, that the library received between two dates. Upon completing the search, the user would be given a list of documents that met the search criteria. A user or end user may be a person, device, program, or computer system that utilizes the library for data processing and information exchange.
In addition to retrieving documents based on specific search criteria, the DIA document library service provides for the formation of relationships between documents. These document relationships were originally conceived by M. G. Macphail and disclosed in co-pending application Ser. No. 07/454,797, entitled "A Method of Filing Stapled Documents within an Application", which is incorporated herein by reference.
One example of such a document relationship is the concept of folder documents. A folder document is created when a user groups documents into a linear or hierarchical structure. Documents assume a linear structure when they are organized by placing a set of documents in a user specified position within a particular folder. Documents can assume a hierarchical structure by nesting documents that are folders, or more simply, putting a document that is itself a folder into another document that is a folder. Each document in a folder, regardless of its relationship with other documents, has separate document definitions including descriptors, access control, and document content. Therefore, access to one document contained within a particular relationship implies nothing with respect to access to other documents within the same relationship. All documents in the DIA document library have a Library Model Object, called the Document Relation Object, associated with them that describes the document relationships. Therefore, when there is a need to access a folder, each Document Relation Object for each document in a folder must be accessed to determine the complete relationship between the documents.
Another example of a document relationship allowed in a DIA library is the staple relationship. The staple relationship allows a user to attach two documents together. Staple relationships provide a tightly bound, directed, one-to-one document relationship between documents. In addition, the stapled documents can be placed within a folder document. The Document Relation Object for each of the documents as previously described for folder documents, must describe the relationship between the stapled documents as well as the relationship between the folder documents. Thus, each document within the relationship contains its own particular attributes such as language, document type, character sets and other profile information which describes the characteristics of the document itself. For example, if all documents in a relationship were composed in French, each document would have profile information specifying that the document was in French.
Any user seeking to access the documents defined by the relationship, would have to read and decipher each document's profile to determine the attributes of all documents within the relationship. Consequently, what is needed is a means to specify the attributes once, and to identify all documents within a relationship which contain those particular attributes.
SUMMARY OF INVENTION
This invention relates to a method of reducing storage requirements and complexity in a document management system when specifying attributes that occur multiple times in a plurality of documents. Document management systems store attributes such as language, document type, and character sets with the document contents. When individual documents are combined with other documents to create relationships such as folders or stapled documents, each individual document must be queried to determine its attributes. This invention discloses a Vector Relational Characteristical Object created when a relationship is defined between two or more documents. This Vector Relational Characteristical Object contains a field to identify a particular attribute for at least one document in the relationship. The Vector Relational Characteristical Object is available to document access mechanisms for rapid determination of document attributes without the need for scanning each individual document in the relationship for its attributes.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a document management system where this invention could be practiced.
FIG. 2 is a basic document model created for each document filed in the library of the system shown in FIG. 1.
FIG. 3 is a block diagram of a document relationship illustrating the concept of folder documents.
FIG. 4 is a block diagram of a folder relationship showing a folder in another folder.
FIG. 5 is a block diagram of a staple relationship.
FIG. 6 is a block diagram of stapled documents within a folder.
FIG. 7 shows the basic document model of FIG. 2 with the addition of the Vector Relational Characteristical Object in accordance with the method of the invention.
FIGS. 8 and 9 are structures for a field in the Vector-Relational Characteristical Object.
FIG. 10 is a flow diagram showing how the Vector-Relational Characteristical Object can be used within a document Interchange Management System of FIG. 1.
DETAILED DESCRIPTION
FIG. 1 shows a document management system for managing documents in an information processing system. A user 20 is permitted to store and retrieve documents from library 28. The library 28 is capable of being accessed simultaneously by other users and therefore represents a shared library. Unlike library 28, a user's personal or private documents are stored in local document storage 24. This local document storage 24 is usually not shared with other users. A user 20 accesses his local document storage 24 through the manager/requester 22. The manager/requester 22 also interfaces with the library server 26 which controls user's access to the library 28. When a user 20 files a document in the document library 28, the library server 26 must construct parameters or descriptors that describe the contents of the information being stored in the library.
Referring to FIG. 2, a basic document model is shown for information stored in the library 28 shown in FIG. 1. This document model is created by the library server 26 and is stored with each document. While it is not necessary to implement the basic document model explicitly to support DIA library service architecture, there is the requirement that a design be mapped to these models, or to a subset of them.
The User Profile Object 36 (UPO) is not part of the DIA document model, but is instead an object referred to by the DIA document model. The User Profile Object 36 is created when the users they represent are logged members of an Office System Network. It identifies a user and contains information about the user such as aliases, services authorized to the user, default accounting information, and other user-specific information.
The Document Model Object 30 is the heart of the DIA document model and is logically the first object created when a document is filed for the first time in a document library. It contains information concerning ownership and attributes of a particular document. More specifically, it contains document instance attributes, such as whether the document is editable or not-editable; the maximum number of versions; and the action to be taken if the user has attempted to edit a document that cannot be edited. In addition, the Document Model Object 30 may contain any of the following information:
1) Document level locking information indicating the user who has checked a document out of the library for updating;
2) Indications that a document contents has been removed from direct control of the library server;
3) Directions to a library administrator to remove parts or restore parts of a document to library service control;
4) Time and date information was removed from direct control of the library server;
5) Location of information removed from direct control of the library server; and
6) Optional information for archival purposes.
The Access Control Model Object 32 (ACMO) is created when a document is filed for the first time into a DIA library. The principle purpose of the Access Control Model Object 32 is to consolidate information to be used in determining non-owner access to the document. It contains access control information such as whether the document is capable of being accessed by any one (public), whether access is permitted to a limited number of explicitly specified users (private), or whether the information is shared with others. The Access Control Model Object 32 also contains information that governs the retention and disposal of the document.
The Document History Log Object 34 (DHLO) is optionally created when a document is filed in the library and the user wishes to record various activities on the document. For example, a user may wish to record the number of times the document was read and by whom.
The Document Relation Object 42 (DRO) is created when a document is first filed in the library. Its purpose is to describe the logical relationships between a document and other related or grouped documents. For example, the DIA architecture allows folder documents to be created that contain other documents. When such a relationship exists, then each document contained within the folder has a pointer entry called a Library Assigned Document Name (LADN) in the Document Relation Object 42.
The Version Control Object 40 (VCO) is created when a document is first filed into the library and contains information for several objects that may comprise a single named version of a document. It provides space for version naming, version level locks, and other version related level process controls.
The Profile Content Object 44 (PCO) is created when a document is first filed into the library and a user wishes to create sub-objects for performance or other reasons. The Profile Content Object 44 is the repository for Profile information related to the sub-objects.
The Document Content Object 46 (DCO) is created when a document is first filed into the library and provides storage for the document contents. In addition, the Document Content Object 46 provides storage for saving information concerning the actual size of the document in various units of measurement.
The Search Index Object 48 (SIO) contains entries used in searching within a document. The entries are placed in the SIO as a result of the following sequence of actions on other objects. The basis Document Model Object 30 is first created as part of processing a FILE command. The Library Server then scans the Profile Content Object 44, the Document Relation Object 42, and the Access Control Model Object 32 to find terms to be used to support a parametric SEARCH. As each search term is identified, an entry is made in the Search Index Object 48 whose name includes the parametric search term value and semantics. If no SIO 48 exists when the Library Server scans the aforementioned objects, one is created and the entries placed therein as if the Search Index Object 48 always existed.
The Reverse Search Index Object 38 (RSIO) exists to support the removal of Search Index Object 48 entries when a document is removed from the library by a DELETE command. Entries for parametric search terms are placed in the RSIO 38 at the same time they are being made in the Search Index Object 48.
Referring to FIG. 3, a document relationship representing a folder is shown. Document A (56) and document B (54) represent individual items contained in folder document 1 (50). Document A (56) is also contained in folder document 2 (52) along with document C (58). Folder document 1 (50) and folder document 2 (52) might be individual personnel jackets and document A (56) might be a document explaining a personnel policy. Only one actual copy of document A 56 is needed and that copy is always consistent across personnel jackets. The relationship between the documents and the folders are contained in the Document Relation Object (DRO). Access to the documents in each folder requires the Library Server access the Document Relation Object of each document to determine the relationship.
Turning to FIG. 4, expansion of the document in a folder concept is shown to include a folder in a folder. Document A (56) and document B (54) are items in folder document 2 (52). Folder document 2 (52) is then placed into folder document 1 (50). For example, folder document 1 (50) may be a corporate opinion survey report while document 2 (52) may be the Austin survey report. Document A (56) and document B (54) may be survey reports from two different areas in Austin. Again, each time the Library Server accesses the documents shown in this relationship, the Document Relation Object for each of the items must be examined.
Referring to FIG. 5, another document relationship is shown where one document is stapled to another. Document 1 (60) is stapled to document 2 (62) which is stapled to document 3 (64). The staple relationship allows the user to attach two documents together. The Document Relation Object (DRO) for each document contains the current state of the relationship.
Further examples of various combinations of staple and folder relationships are shown in FIG. 6. Document 1 (60) and document 2 (62) may be stapled together and placed in folder document 1 (50) along with document 4 (66). In the same manner, document 3 (64) may be stapled to document 2 (62) and placed in folder document 2 (52). Also included in folder document 2 (52) is document 5 (68). Each document within the folder contains its own particular attributes such as language, document type, character type, character sets and other profile information which describes the characteristics of the document itself. In order to access documents within the folder, the Library Server has to read and decipher each document's profile to determine the attributes of all documents within the relationship. For example, if all documents in the relationship were composed in French, each document would have profile information specifying that the document was in French. This invention eliminates the problems of having to store this attribute information in every document through the creation of a "Vector-Relational Characteristical Object" (VRCO).
Turning to FIG. 7, the basic document model for the DIA Document Library Services is shown with the Vector-Relational Characteristical Object 70 (VRCO) of this invention. The VRCO 70 contains fields to identify a particular attribute which exist for at least one of the documents in a relationship. The fields are followed by identifiers which uniquely identify the documents which possess the particular attributes.
FIGS. 8 and 9 are typical examples of how the fields appear in the VRCO 70. Referring to FIG. 8, if documents 1, 2, and 3 all possess attribute X, and documents 1, 2, and 6 attribute Y, the Vector-Relational Characteristical Object (VRCO) would contain the fields shown in FIG. 8. There is no need to specify in the profile of each of the documents attributes X and Y since the VRCO already contain the information. The occurrence of a new attribute indicates the end of all documents that possess the previous attribute.
This invention permits the Library Server to rapidly access the attributes of documents which are in relationships to each other when requested by an application by reading the VRCO. Thus, the relationship of documents to each other can be rapidly accessed when such relationships are stored in the VRCO. The concept of placing attributes/characteristics that require rapid access in a VRCO are more clearly shown in the following example. Suppose an application was only capable of understanding a particular character set for the contents of a document. The application could quickly scan the VRCO, checking for documents that possess that particular character set. The application could then present only those documents to the user for presentation and ignore or delete documents for which the application does not support. Therefore, this invention permits applications to rapidly free up resources for documents which possess characteristics for which the application can not support.
The Vector-Relational Characteristical Object (VRCO) can also contain a VECTOR-BASE value to specify if the vector is to be based off of an attribute, or off the document identifier. FIG. 9 more clearly illustrates how the fields would appear in the VRCO. The VECTOR-BASE field contains a value to indicate if the vector is based off the document identifiers or the document attributes. Document 1 has attributes X, Y, and Z and document 2 has the Y attribute. The variability of basing the vector off the document can save storage when the number of documents is relatively large in relationship to the number of attributes defined, as shown in FIG. 9.
Referring to FIG. 10, a flow diagram is shown for Vector-Relational Characteristical Object usage. In step 71, a user decides to create a relationship between document A and document B. It is first determined in step 72 if document A has a VRCO. If document A already has a VRCO, we next determine in step 74 if document B possess a VRCO. In step 76, if both documents already contain a Vector-Relational Characteristical Object, we identify any attributes in document B that are not in document A. The VRCO analysis is completed by modifying the VRCO, step 78, of document A to reflect the new relationship between the documents. Only one VRCO will exist to define the relationship between the documents.
If the user finds after deciding to form a relationship between document A and document B that no VRCO exist for document A. Step 84 requires a determination of whether a VRCO exists for document B. When document B is found to have a VRCO, profile information is extracted in step 86 from document A and placed in the VRCO of document B. Attributes from document A are also identified in step 88 and placed in the VRCO of document B. Finally, the document B VRCO is modified in step 90 to reflect the attributes in document A. This method provides for one VRCO per relationship. No matter how many documents are created in the relationship, only one VRCO exist for the relationship. This significantly reduces the amount of storage, necessary to retain attributes of a document.
In the same way, if a VRCO exists for document A and not for document B, profile information is extracted in step 82 from document B. Attributes are identified in document B, step 80 and the VRCO for document A is modified to reflect the new relationship between the documents in step 78.
Finally, if neither document has a VRCO associated with it, step 73 requires the creation of a VRCO for document A. In step 82, profile information is extracted from document B and placed in the VRCO. In step 80, attributes for document B are identified and placed in the VRCO. In step 78 the VRCO for document A is modified to reflect the new relationships between document A and document B.
In summary, this invention discloses a method of identifying document attributes when a plurality of documents are combined in unique document relationships. These document relationships include folders, staple documents, various combinations of the folder and staple concepts, or any relationship where documents within a relationship contain at least one similar attribute. A Vector Relational Characteristical Object (VRCO) is added to the set of objects forming the basic document model as implemented in the Document Interchange Architecture (DIA). The Vector Relational Characteristical Object is available to document access mechanisms and contains fields for specifying the attributes once for each document in a relationship. The VRCO reduces storage requirements by providing for storage of the attribute only once when the document relationships are created. The VRCO contains a field to identify a particular attribute which exist for at least one of the documents in the relationship. The field is then followed by an identifier which uniquely identifies the document which possess the particular attribute. Since the attribute is stored only once and in a single object, it can be rapidly accessed to determine if an attribute exist for a particular document.
While the invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and detail may be therein without departing from the spirit and scope of the invention. | This invention relates to a method of identifying attributes when documents are grouped to form document relationships within a document management system. Document groupings frequently require the identification of all documents within the relationship with a particular attribute. However, when individual documents store attributes along with document contents, individual querying of each document is required when the information is sought later. This invention provides a Vector Relational Characteristical Object, available to access mechanisms, and containing fields to identify a particular attribute. Each field in the Vector Relational Characteristical Object is followed by an identifier which uniquely identifies the document which possess the particular attribute. | 8 |
BACKGROUND OF THE INVENTION
This invention pertains to a new and improved closure operator for moving a closure which is guided for movement in a fixed path between open and closed positions and maintaining the closure in the desired position.
SUMMARY
A primary feature of the invention disclosed herein is to provide a closure operator having linkage structure operable by a handle for moving a closure between open and closed positions and securely holding the closure in either of the positions.
Another feature of the invention is to provide a closure operator having spring means associated with the linkage structure which assists in holding the linkage structure in a pre-set position and which, additionally, smooths out the action of the mechanism and retards closing of the closure when gravity acts on the closure in a closing direction.
In carrying out the foregoing features, a primary object of the invention is to provide a closure operator having a base, an opener link connectable to a closure, an operating handle movable on the base between two positions, an idler link movably mounted on the base and pivotally connected to the opener link adjacent an end thereof to control movement of the opener link relative to the base, and a driver link pivotally connected to both the handle and the opener link to impart handle movement to the opener link with the idler link partly guiding the movement of the opener link.
Additionally, the closure operator has the aforesaid linkage structure related whereby an over-center relation is obtained in both open and closed positions of the linkage structure whereby a force applied to the closure will not cause movement of the linkage structure. The idler link which guides an end of the opener link during movement thereof has a curved slot receiving a pivot means for the handle and with the ends of the curved slot limiting pivotal movement of the idler link to establish a fixed position for an end of the opener link in both open and closed positions and with the idler link being fixed at one limit position providing for a controlled, tight lock-up of the closure in response to movement of the handle. The aforesaid spring means comprises a tension spring connected between the base of the closure operator and the driver link and positioned to yieldably hold the driver link in an over-center position in both open and closed positions of the linkage structure and to exert additional opposing force as the driver link is moved between said positions by operation of the handle.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of the closure operator shown connected to a part of a closure and having parts broken away;
FIG. 2 is a view, similar to FIG. 1, showing the closure operator and closure in closed position, with parts broken away; and
FIG. 3 is a sectional view, taken generally along the line 3--3 in FIG. 1, and with the closure omitted.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The closure operator is usable primarily for operating a closure having a small degree of opening movement as, for example, an automotive vehicle sun roof. Such a closure is shown broken away at 10 in FIGS. 1 and 2. Such a closure is guided for movement in a fixed path as defined by hinge means (not shown) for the closure which cause the closure to move generally in a straight line and in an opening direction, as indicated generally by the arrow 11, and in a closing direction, as indicated generally by the arrow 12. Proper operation of the closure operator disclosed herein requires the fixed path or essentially straight-line movement of the closure.
The closure operator has a generally planar plate 15 defining a base for the closure operator and having flange elements 16 to receive fasteners 17 for mounting thereof to a support surface.
A handle 20 having a handle grip 21 fitted thereon is pivotally mounted on the base 15 by means of pivot means in the form of a rivet 22 and with an idler link 25 positioned therebetween.
The handle 20 is operable between two limit positions determined by engagement of the handle with a pair of tabs 26 and 27 turned up from the base 15. The open limit position for the handle is shown in FIG. 1 and the closed limit position for the handle is shown in FIG. 2.
An opener link 30 has one end pivotally connected to a closure bracket 31 secured to the closure. A stud 32 on the bracket passes through a hole in the opener link and is captured by a conventional type slidable keeper 33. An opposite end of the opener link 30 is pivotally connected to an end of the idler link 25 by pivot means in the form of a rivet 35. The idler link intermediate its ends is pivotally mounted on the base 15 by pivot means in the form of a rivet 36 whereby pivotal movement of the idler link 25 guides one end of the opener link 30 between the positions shown in FIGS. 1 and 2.
Rotational movement of the handle 20 is translated into movement of the opener link 30 by means of a driver link 40 having a first end pivotally connected to the opener link 30 intermediate its ends by pivot means in the form of a rivet 41 and having a second end pivotally connected to a raised part of the handle 20 offset from the pivot axis of the latter by pivot means in the form of a rivet 42.
Spring means coact with the linkage structure and, as shown, includes a tension spring 50 having an end 51 extended through an opening in the stop tab 27 and having its other end 52 fastened in an opening in the driver link 40.
The idler link 25 has a curved slot 55 near an end thereof which receives the central part of the rivet 22 defining the handle pivot whereby an end 56 of the slot defines a limit for rotation of the idler link 25 in one direction and, thus, the closed position for the idler link as shown in FIG. 2 and the other end 57 of the curved slot defines a limit position for the idler link in the open position of the closure, as seen in FIG. 1.
A decorative case encloses the operator structure and has enclosing parts 60 and 61 with a slot 62 therebetween to permit free movement of the handle 20 between the positions of FIGS. 1 and 2.
With the closure in open position, as shown in FIG. 1, the handle 20 is in a limit position against the stop tab 26 and tension spring 50 is acting in a direction to maintain the driver link 40 in the position shown. Any force applied to the closure 10 in a closing direction or downwardly, as viewed in FIG. 1, will not move the closure, since the linkage structure is in an over-center position. Such a force applied to the driver link 40 through the rivet 41 will exert a force on the rivet 42 interconnecting the driver link and the handle and urge the handle 20 in a counterclockwise direction, with such movement thereof being blocked by the stop tab 26. The idler link will not move because of engagement between slot end 57 and the rivet 22. Additionally, any force applied to the closure 10 urging the closure toward the right, as viewed in FIG. 1, is resisted by the idler link 25 having the slot end 57 positioned against the rivet 22.
Clockwise rotation of the handle 20 from the position of FIG. 1 to the position of FIG. 2 results in a pull on the driver link 40 to exert a pull on the opener link 30 and move the closure 10 to closed position. With the closure being constrained for movement in a fixed path, there is a resulting movement of the opener link 30 toward the left, as viewed in FIG. 2, as permitted by counterclockwise rotation of the idler link 25. The movement of the idler link is stopped by engagement of the end 56 of the curved slot, with the handle-pivoting rivet 22, whereby final movement of the handle against the stop tab 27 provides for a tight lock-up of the closure. Any force applied to the closure 10 tending to open it is prevented by the over-center relation of the linkage and, particularly, the relation of the two pivot connections 41 and 42 of the driver link 40 to the opener link 30 and the handle 20 to the pivot axis for the handle defined by the rivet 22. As seen in FIG. 2, an upward force applied to the opener link 30 reacts on the handle 20 in a direction attempting to cause clockwise pivoting thereof and this is prevented by the handle being engaged against the stop tab 27. The idler link 25 is blocked against counterclockwise rotation. The tension spring 50 assists in maintaining this relation.
Additionally, the tension spring 50 smooths out the action of the mechanism and assists in a controlled closing action. As the linkage structure moves from the position of FIG. 1 to the position of FIG. 2, the driver link 40 moves in a direction to stretch the tension spring 50 and the resistance imposed by the spring acts to oppose downward free fall of the closure. | A closure operator for a pivotally mounted closure, such as a vehicle sun roof or a pivoted window, having a series of pivotally interconnected links including an opener link pivoted to the closure and to an idler link which is pivotally mounted to a base. A driver link is pivotally connected between the opener link and a handle rotatable on the base whereby handle movement is imparted to the driver link for moving the opener link and the closure and with the movement of the opener link being partly guided by the idler link. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an apparatus for acquisition of an asynchronous, wideband DS/CDMA signal.
2. Description of the Related Art
An asynchronous, wideband, direct-sequence/code division multiple access (DS/CDMA) system is one of the next generation of mobile communication systems suggested in Japan and Europe. An asynchronous, wideband DS/CDMA system has an advantage that external timing information is not required, which is different from other DS/CDMA systems. In a conventional DS/CDMA system, the acquisition of code must precede the demodulation of data, however, in the case of an asynchronous system, base stations use different codes, so that it takes more time for the acquisition than in a synchronous system.
The asynchronous, wideband DS/CDMA system is a system that identifies channels or users by using a spreading code, so that its transmitter transmits signals of the modulated data multiplied by the spreading code. In the asynchronous, wideband DS/CDMA system, in order for a mobile terminal to demodulate the data transmitted from the base station, it must be preceded by an acquisition process. In a synchronous system such as the IS-95, which is now commonly used, all the base stations use the same codes and each base station is identified by a different offset, so that an acquisition process means a process for searching for the offset of the code used in the base station to which the mobile terminal belongs.
If the acquisition is not achieved, it is impossible to estimate the phases of channels. Therefore, generally a noncoherent detector, which can discriminate whether acquisition is achieved or not regardless of the phases of channels, is used in the acquisition process. FIG. 1 is a block diagram of a noncoherent detector. The noncoherent detector according to FIG. 1 includes an antenna 100 , a local oscillator (LO) 102 , a mixer 104 , a correlator 106 , a square multiplier 108 , and a discriminator 110 .
The operation according to the above structure is as follows. The antenna 100 receives a high frequency signal that has experienced fading and additive noise through radio channels. The mixer 104 multiplies the received signals by a signal produced in the local oscillator 102 and changes the received signal into a complex signal of base band. The correlator 106 correlates a real component and an imaginary component of the complex signal, respectively. The square multiplier 108 squares the correlated signal and removes a phase component induced by the channels. The discriminator 110 decides whether acquisition is achieved or not by discriminating the output values of the square multiplier 108 .
The correlator 106 can be an active correlator or a matched filter correlator. An active correlator performs a correlation by multiplying codes generated by an internal code generator by the received signal and then by integrating the multiplied values over a correlation interval. Realization of the active correlator is relatively simple but the acquisition time thereof is long. The matched filter correlator has an advantage in that it takes a shorter time for acquisition than the active correlator, since the matched filter correlator can test different phases at every chip time.
FIGS. 2 ( a ) through 2 ( e ) illustrate the correlation results of the matched filter correlator for the case where acquisition is achieved and for the case where acquisition is not achieved, when the power of the received signal is 1 and ideal channels having no noise and fading are assumed. Symbol r k illustrates samples of the received signal at each tap of the matched filter. Symbol c k illustrates tap coefficients of the matched filter, and symbol p k illustrates the product of r k and c k .
FIG. 2 ( a ) illustrates c k , the tap coefficients of the matched filter. FIG. 2 ( b ) illustrates r k , the samples of the received signals when acquisition is achieved (in-sync), and FIG. 2 ( c ) illustrates p k , the results of multiplying the values illustrated in FIGS. 2 ( a ) and 2 ( b ). According to these figures, if acquisition is achieved, all the p k values become 1 and the output value of the matched filter become 1.
FIG. 2 ( d ) illustrates r k , the samples of the received signals when acquisition is not achieved (out-of-sync), and FIG. 2 ( e ) illustrates p k , the results of multiplying the values illustrated in FIGS. 2 ( a ) and 2 ( d ). According to these figures, if acquisition is not achieved, the p k values become 1 or −1, and the sum thereof becomes much smaller than 1. In fact, due to the fading and additive noise of the channels, each of the output values of the matched filter becomes a complex number, and the outputs of the matched filter in the in-sync case can be smaller than the outputs of the matched filter in the out-of-sync case, which can result in a false lock.
In addition, if a signal-to-noise ratio is low, or the signal components are attenuated by the fading, it is impossible to make a reliable decision on whether acquisition is achieved or not only with the outputs of the matched filter of the received signal for the predetermined interval. Therefore, it can be more reliable to decide by combining the outputs of the matched filter obtained repeating for the above interval.
As a method for combining the outputs of the matched filters, there is a coherent combination method or a noncoherent combination method. The coherent combination method continuously accumulates the outputs of the matched filter during L intervals (where L is a positive integer), and then, squares the accumulated result and decides whether acquisition is achieved. However, performance of the coherent combination method is rapidly degraded if the fading or the offset of the frequency increases to more than a threshold value. The noncoherent combination method squares the outputs of the matched filter during the L intervals and linearly combines them to decide whether acquisition is achieved or not. That is, the output of the noncoherent combination method becomes the sum of the outputs of the noncoherent detector. However, performance of the noncoherent combination method is seriously degraded if the signal-to-noise ratio (SNR) worsens.
SUMMARY OF THE INVENTION
To solve the above problems, it is a feature of an embodiment of the present invention to provide an apparatus that achieves signal acquisition of an asynchronous, wideband direct-sequence/code division multiple access (DS/CDMA) signal, which decides whether acquisition is achieved or not by differentially coherently combining the i-th and the (i- 1 )-th outputs of a matched filter during the L intervals.
It is another feature of an embodiment of the present invention to provide an apparatus for acquisition, which acquires a long code from a direct-sequence/code division multiple access (DS/CDMA) control channel signal, in which a common short code and the long code are transmitted within one frame, and a group identification code indicating a code group to which a base station belongs, are combined and transmitted with the common short code. The apparatus for acquisition includes: a long code masking correlation portion for correlating common short codes generated internally and the control channel signal; a differentially coherent combining portion for deciding whether acquisition of the common short code is achieved or not by multiplying a complex conjugate value of previous output of the long code masking correlation portion by present output of the long code masking correlation portion, and by accumulating the results of multiplication during the predetermined times and by taking an absolute value of the accumulated value; a code group and frame timing acquisition portion for acquiring the code group and frame timing by correlating each group identification code, which can be generated according to the coherence of the common short code, and the received group identification codes respectively, and by combining each correlation result; and a long code acquisition portion for acquiring the long code by correlating long codes belonging to the acquired code groups and the received long code respectively.
It is an additional feature of an embodiment of the present invention to provide an apparatus for acquisition, which acquires a long code from a direct-sequence/code division multiple access control channel signal, in which a common short code, and the long code are transmitted within one frame, and a group identification code indicating a code group to which a base station belongs, are combined and transmitted with the common short code. The apparatus for acquisition includes: a long code masking correlation portion for correlating common short codes generated internally and the control channel signal; a switch for connecting each output of the long code masking correlation portion to output terminals which exist as many as the number of the common short code, and repeating this process; a differentially coherent combining portion for deciding whether acquisition of the common short code is achieved or not, by comparing values output from a means wherein the means delays a value input from the output terminal connected to the switch for a predetermined time, takes a complex conjugate of the delayed value, multiplies the complex conjugated value by the value input from the output terminal, accumulates the multiplied value for a predetermined times, and takes an absolute value of the accumulated value; a code group and frame timing acquisition portion for acquiring the code group and frame timing by correlating each group identification code which can be generated according to the coherence of the common short code, and the received group identification codes respectively, and by combining each correlation result; and a long code acquisition portion for acquiring the long code by correlating the long codes belonging to the acquired code group and the received long code respectively.
These and other features and advantages of the present invention will be readily apparent to those skilled in the art upon review of the detailed description that follows.
BRIEF DESCRIPTION OF THE DRAWINGS
The above features and advantages of the present invention will become more apparent by describing in detail a preferred embodiment thereof with reference to the attached drawings in which:
FIG. 1 illustrates a block diagram of a noncoherent detector;
FIGS. 2 ( a ) through 2 ( e ) illustrate correlation results of a matched filter correlator for the case where an acquisition is achieved and for the opposite case where a power of received signal is 1, with ideal channels having no noise and fading;
FIG. 3 illustrates a block diagram of an asynchronous, wideband direct-sequence/code division multiple access system transmitter which produces control channel and traffic channel;
FIGS. 4 ( a ) through 4 ( d ) illustrate a pattern of a CCH signal made by the direct-sequence/code division multiple access of FIG. 3 ;
FIG. 5 is a block diagram of an apparatus for acquisition of a wideband DS/CDMA signal according to the present invention;
FIG. 6 is a detailed block diagram of an LC masking interval correlation portion and a differentially coherent combining portion shown in FIG. 5 ; and
FIG. 7 is another preferred embodiment of the LC masking interval correlation portion and the differentially coherent combining portion shown in FIG. 6 .
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Korean patent application number 99-57989, filed on Dec. 15, 1999, and entitled: “Apparatus of Acquisition of Asynchronous Wideband DS/CDMA Signal,” is incorporated by reference herein in its entirety.
FIG. 3 is a block diagram illustrating an asynchronous wideband DS/CDMA system transmitter that produces a control channel (CCH) and a traffic channel (TCH). The transmitter in FIG. 3 includes a CCH data modulator 300 , a first short code generator (SC 0 ) 301 , a first multiplier 302 , a masking controller 303 , a second multiplier 304 , a third multiplier 305 , a first adder 306 , a long code generator (LC) 310 , a group identification code generator (GIC) 311 , TCH data modulators 321 through 323 , short code generators (SC 1 , SC 2 , SC M-1 ) 331 through 333 , multipliers 341 through 343 , a second adder 350 , a third multiplier 351 , and a third adder 360 .
The CCH data modulator 300 and the TCH data modulators 321 through 323 modulate respectively the input CCH data and TCH data. The first short code generator 301 and the short code generators 331 through 333 generate M short codes (SC) (where M is a positive integer), and among the SCs, SC 0 is used for the CCHs, and SC 1 through SC M-1 are used for identifying the TCH respectively. The SCs are common to all base stations, and are orthogonal to each other. Here, M is the same as a processing gain, the number of chips multiplied per data symbol, and one period of the SC is equivalent to one symbol interval. That is, a chip time is 1/M of the symbol interval. Long codes (LC) generated from the long code generator 310 are unique to each base station and used for identifying a base station. The GIC generated from the GIC generator 311 is a SC for identifying code groups to which a base station belongs, and the W LC sequences form one code group (where W is the total number of LS sequences).
The first multiplier 302 multiplies the SC 0 generated by the first short code generator 301 by the output of the CCH data modulator 300 . The masking control portion 303 controls the masking of the predetermined intervals of the outputs of the CCH data modulator 300 and the first multiplier 302 from the outputs of the long code generator 310 and the GIC generator 311 , and the second and the third multipliers 304 and 305 perform masking according to the control of the masking controller 303 . The first adder 306 adds up the outputs of the second and the third multipliers 304 and 305 , and then outputs the added result as a CCH.
The multipliers 341 through 343 multiply each output of the TCH data modulators 321 through 323 by each output of the short code generators 331 through 333 respectively, and the second adder 350 adds up the outputs of the multipliers 341 through 343 . The third multiplier 351 multiplies the output of the second adder 350 by the output of the long code generator 310 , and the outputs the added result as a TCH. The third adder 360 adds the CCH to the TCH and transmits the result.
The mobile terminal uses a CCH signal transmitted from a base station for acquisition. The CCH signal has a form that the LC inherent to a base station is masked periodically for an MTc (Tc: chip time), a period of the SC. Thus, the SC only appears for the MTc and the LC only appears for the rest. That is, the SC and the LC are time-multiplexed and transmitted.
FIGS. 4 ( a ) through 4 ( d ) illustrate the CCH signal pattern made in FIG. 3 . FIG. 4 ( a ) illustrates the LC period of one frame. FIG. 4 ( b ) is the LC formed of L slots, and the length of each slot is NTc. At each slot, the LC is masked for one period (MTc) of the SC. In the masking section, the SC is formed of the sum of two codes, which are orthogonal to each other. One of the two codes is a common short code (CSC) such as SC 0 shown in FIG. 4 ( c ), and the other code is a GIC shown in FIG. 4 ( d ).
FIG. 5 is a block diagram that illustrates the apparatus for acquisition of wideband DS/CDMA signals according to the present invention. The apparatus for acquisition according to FIG. 5 includes an LC masking interval correlation portion 500 , a differentially coherent combining portion 502 , a GIC acquisition portion 504 , and an LC acquisition portion 506 .
The LC masking interval correlation portion 500 correlates the CSC generated within the receiver and the received signal. The differentially coherent combining portion 502 combines differentially coherently the correlation results of the LC masking interval correlation portion 500 , and decides whether slot acquisition is achieved or not. The GIC acquisition portion 504 correlates the GIC and the LC masking interval, and combines the results of the matched filtering for one or more frames and chooses the GIC having the biggest combination result. The chosen GIC is determined to be the code group of the base station to which a mobile terminal belongs, and at the same time frame acquisition is achieved. The LC acquisition portion 506 match-filters W LCs, which belongs to the code group obtained in the GIC acquisition portion 504 and the other sections except the LC masking interval and chooses the LC having the biggest match-filtered result.
FIG. 6 is a block diagram that illustrates the operation of the LC masking interval correlation portion 500 and the differentially coherent combining portion 502 performed during the predetermined slot section. According to FIG. 6 , the LC masking interval correlation portion includes correlators (MF) 601 through 604 , and the differentially coherent combing portion includes conjugators 611 through 613 , multipliers 621 through 623 , adders 631 and 632 , an absolute value calculator 640 , and a discriminator 650 .
The correlators 601 through 604 correlate the received signal and the CSCs. Here, the correlators 601 through 604 are matched filters. The matched filters include M tabs, and the tab coefficients are the CSCs. The matched filters produce one output at every chip time.
The conjugators 611 through 613 output the complex conjugate values of the outputs of each of the matched filter 601 thorough 604 . The multipliers 621 through 623 multiply the complex conjugate outputs of the previous slots by the correlator outputs of the present slots. Each of the adders 631 and 632 adds up the outputs of the multipliers 621 through 623 outputted at every chip time. The absolute value calculator 640 takes the absolute value of the final results of the adding up, and the discriminator 650 detects the LC masking interval by choosing the time when the absolute value becomes the biggest.
The block diagram shown in FIG. 6 assumes that there are a plurality of correlators (MF) 601 through 604 , a plurality of conjugators 611 through 613 , a plurality of multipliers 621 through 623 , and a plurality of adders 631 and 632 in order to explain briefly the operations performed during the predetermined slot. However, in fact, a correlator, a conjugator, a multiplier, and an adder perform the operations sequentially at every chip time.
FIG. 7 is another preferred embodiment of the LC masking interval correlation portion 500 and the differentially coherent combining portion 502 shown in FIG. 6 .
According to FIG. 7 , the LC masking interval correlation portion is formed of a CSC correlator 72 , and the differentially coherent combining portion includes a switch 73 , delays 701 through 703 , complex conjugators 711 through 713 , multipliers 721 through 723 , adders 731 through 733 , absolute value calculators 741 through 743 , and a discriminator 750 . Reference numeral 70 indicates a local oscillator (LO) and reference numeral 71 indicates a converter 71 that converts received signal into base band signals by multiplying received signal by signal generated in the local oscillator 70 .
The operation is as follows. The CSC correlator 72 is a matched filter, and the matched filter coefficients are the CSC. The matched filter outputs identical code phase with period of a slot (NTc) at every chip time. Therefore, it can be decided whether acquisition is achieved or not by storing the matched filter outputs corresponding to each of the N different code phases in a memory (not shown) and differentially coherently combining values stored in memory for L slots and accumulating them and then taking the absolute value on the accumulated result. The acquisition decision value (Z n ) of the n-th code phase in the LC masking interval of each slot is obtained as follows. First, each delay 701 through 703 delays each value passing through the switch 73 for the Ntc, a duration of one slot. Each complex conjugator 711 through 713 takes the complex conjugate of the outputs of each delay 701 through 703 . Each multiplier 721 through 723 multiplies signal passing through the switch 73 at the present chip time by outputs of the complex conjugators 711 through 713 respectively. That is, the n-th output complex conjugate of the CSC correlator 72 is multiplied by the N+n-th output of the CSC correlator 72 , the N+n−th output complex conjugate of the CSC correlator 72 is multiplied by the 2N+n−th output of the CSC correlator 72 , . . . , the (L−1)N+n−th output complex conjugate of the CSC correlator 72 is multiplied by the (L)N+n-th output of the CSC correlator 72 . As a result, (Z n0 ⋆ Z n1 ), (Z n1 ⋆ Z n2 ) . . . , (Z n(L-1) ⋆ Z nL ) are output. Each adder 731 through 733 accumulates the same number of outputs of the multipliers 721 through 723 as the number of L slots. Each of absolute value calculators 741 through 743 takes the absolute value of each of the accumulated values. The discriminator 750 chooses a code phase corresponding to the biggest value among the decision values of the number N (Z n : n=1, 2, . . . , N), and decides whether acquisition is achieved. If the decision is wrong, the above process is repeated. The matched filter outputs for the L+1 slots are required in order to obtain N decision values. However, after the second decision, the matched filter outputs of the last slot used for the previous decision can be used, so that the matched filter outputs of only the L slots are required. For the differentially coherent combination, the 2N memories for storing N matched filter outputs and N accumulated values are required. Also, the L complex conjugating means and the multiplying means are required, and the L−1 adding means are required.
The differentially coherent combining means of the present invention has a higher reliability of the decision values as the number of combined slots increases. However, the acquisition receiver becomes more complicated and it takes longer to obtain a decision value. Therefore, the number of combined slots should be chosen properly, reflecting the acquisition time and complexity.
Although the present invention is explained only with the examples of the differentially coherent combination, the combining method adopting both the coherent combination and the differentially coherent combination can be used. That is, the decision value can be obtained by coherently combining combined results and the slots which are not so much influenced by fading and frequency offset and accumulating the coherently differentially coherent combining the accumulated results. Here, the number of total slots is a product of the number of slots coherently combined and the number of slots differentially coherently combined.
According to an embodiment of the present invention, first, since the differentially coherent combining outputs of the matching filters on various slots obtain a decision value having a big combination profit comparing with the asynchronous combination, and a decision of higher reliability can be given, a time for acquisition can be reduced. Second, if there is a frequency offset, a coherent combination attenuates signal components of a decision value, and a time for acquisition is increased, so that an influence of the frequency offset can be reduced through a differentially coherent detection. Third, after the combination, an influence of a fading and a frequency offset can be reduced by catching all signal energy dispersed into a real component and an imaginary component by fading and frequency offset. Fourth, it can be used for not only an asynchronous DS/CDMA system but also a synchronous DS/CDMA system or an acquisition of a system using a pilot signal.
While the present invention has been described in terms of preferred embodiments, those of ordinary skill in the art will recognize that various modifications may be made to the invention without departing from the spirit and scope thereof. | An apparatus for acquisition of an asynchronous wideband direct-sequence/code division multiple access signal, which acquires a long code from a direct-sequence/code division multiple access control channel signal, in which a common short code, and the long code are transmitted within one frame, and a group identification code indicating a code group, to which a base station belongs, are combined and transmitted with the common short code, includes: a long code masking correlation portion; a differentially coherent combining portion; a code group and frame timing acquisition portion; and a long code acquisition portion for acquiring the long code by correlating the long codes belonging to the acquired code group and the received long code, respectively. | 7 |
FIELD OF THE INVENTION
The present invention relates generally to a high bay lighting fixture using multiple self-ballasting bulbs. More specifically the invention is designed to replace a high-bay, low-bay warehouse or similar lighting fixture. The invention may include a hanging system that allows the entire assembly to be wired into a new or existing building and supply the lights, ballast and the dome. This fixture uses multiple high efficiency standard fluorescent or other high efficiency light bulbs.
BACKGROUND OF THE INVENTION
Lighting is used to provide light when it is dark or to provide supplemental lighting for a dark area. Often in large buildings, overhead lighting is provided from lights placed near the ceiling of the building and the light is directed downward. Most light bulbs used in these lighting installations are inefficient, and a portion of the energy used in these lights is expended in heat. In the summer, the heat must be cooled with the building air conditioning system. The replacement cost of these bulbs is also high due to the limited number of these bulbs that are produced. Upgrading these lighting systems has been expensive due to the cost to remove the lighting fixture and replace the entire lighting fixture. What is needed is a new lighting fixture that includes the ballast and may further include the dome. The ballast is provided with multiple high efficiency fluorescent bulbs that provide equivalent or superior illumination with improved efficiency and a reduction in the amount of heat that is generated. The invention proposed by this invention provides a solution to all the listed requirements.
U.S. Pat. No. 5,497,048 issued to Burd is for a fluorescent bulb that has multiple fluorescent elements located within the light bulb. This invention provides the equivalent energy efficiency and an equivalent amount of light, but the bulb is a custom light bulb, and the light bulb is not manufactured in high volume. The invention does not provide multiple efficient light bulbs that are cost effective and easily available.
U.S. Pat. No. 5,541,477 issued to Maya et al. is for a single fluorescent bulb that also has multiple fluorescent bulb elements that are connected into a single screw-in base. This invention provides the equivalent energy efficiency and the equivalent amount of light, but the bulb is a custom light bulb, and the light bulb is not manufactured in high volume. The invention does not provide multiple efficient light bulbs that are cost effective and easily available.
U.S. Pat. No. 4,664,465 issued to Johnson et al. is for a bulb with a clip attached that allows the bulb to be attached to a metal strip. The patent covers the clip connected to a hollow tube that can extend from a vertical or horizontal surface. This invention uses a single bulb connected to an elongated metal tube or neck. The invention is intended for wiring to an electrical power source. The invention does not include multiple light sockets that connect into a base that can be screwed into a lamp base.
U.S. Pat. No. 5,356,314 issued to Aorta is for a double-socket electric lamp that screws into an existing lamp base and converts the lamp into a standard lamp socket so a more standard bulb can be screwed into the second socket. This invention is for converting a high output light bulb into a low output light bulb. The invention replaces a single light bulb with another single light bulb. The invention is a converter for converting a light bulb socket from one size to another. The invention is not intended for converting a single light bulb socket into multiple light bulb sockets.
The ideal product would be used where high or low bay lighting would be used that would normally require a ballast for operation. Standard high efficiency light bulbs could be inserted into the multiple sockets to provide equivalent light intensity at a significant reduction in the energy being used.
BRIEF SUMMARY OF THE INVENTION
It is an objective of the present invention to provide an improved lighting system. This system is used instead of a single light bulb requiring a ballast. The lighting fixture is a single fixture configured for multiple standard higher efficiency bulbs. The invention may also include a dome or other reflector to focus the light downward. The fixture involves a multiple light socket candelabra that are wired where warehouse lighting may be used that may require a ballast.
A standard 100-watt incandescent bulb uses 100 watts of energy, a fluorescent light bulb that provides the same amount of light only requires about 25 watts of energy fluorescent light consume 70 to 75% less energy than a standard incandescent light bulb. The light from fluorescent light is similar or superior to the light from an incandescent light, and can be tinted to provide different shades of light to simulate other lighting sources. The fixture requires the installation onto the rafters or ceiling of the building where it is installed in the factory lighting system. A candelabra lighting fixture is then snapped into the existing dome. A reflector dome located in the lighting fixture helps to focus the lighting down to where the light in needed.
A warehouse typically uses a 450-465 watt incandescent, halogen or similar light bulb and ballast system. The proposed invention replaces the single 400-watt light bulb with five fluorescent lights providing the same amount of light. The standard warehouse light uses 450-465 watts to produce the light. The five fluorescent lights only require 230 to 240 watts of energy to produce the same amount of light saving 170 to 225 watts of energy that would be spent in heat. Inside an air conditioned building the 170 to 225 watts of heat would need to be cooled with the air conditioning system within the building. The savings come from two places first the more efficient lights, and second from air conditioning costs. In addition, there can be safety benefits from less ultraviolet rays, and less chance that the fluorescent bulbs will not explode.
When the invention is installed into a new or existing building where the need for a ballast or the enclosure that would normally enclose the ballast. The multiple bulbs can be as little as two to as many bulbs that are required to provide equivalent light output and voltage drop for the incoming voltage. If the lighting is 277 VAC, multiple 277VAC fluorescent bulbs can be used to achieve equivalent or superior light output.
The construction of the invention consists of ajoist or ceiling mounting system where the fixture can be suspended from a chain. The electrical wires from the building are wired into the top of the fixture, where it is wired into each of the sockets in the candelabra fixture. The candelabra arrangement consists of at least two bulb sockets that extend from a base structure. The bulbs can extend from fixed or flexible arms, goosenecks. The bulbs can be threaded into multiple sockets from the base. The sockets can be wired in a series, parallel, or combined series and parallel arrangement that keeps the voltage to a safe level for the lights screwed into the sockets.
A reflector or dome can be integrated onto the lighting fixture to eliminate the hanging fixture normally associated with high bay lighting fixtures. The reflector or dome is retained on the lighting fixture with retaining snap locks and gravity. The reflector focuses light down from the fixture, while a dome helps to defuse the light and provide more even lighting.
Various objects, features, aspects, and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments of the invention, along with the accompanying drawings in which like numerals represent like components.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric exploded view of the lighting fixture.
FIG. 2 is a cross sectional view of the lighting fixture showing the internal components.
FIG. 3 is an electrical diagram of the internal ballast of a florescent light bulb.
FIG. 4 is a schematic representation of the wiring within the lighting fixture.
FIG. 5 is a bottom view of the lighting fixture
FIG. 6 is a side view of the lighting fixture.
DETAILED DESCRIPTION
Referring first to FIG. 1 , that shows an isometric exploded view of the lighting fixture. The fixture works with store, warehouse or industrial lighting system. The lighting fixture is intended for use as high bay, low bay lighting or similar lighting fixture where incandescent, halogen, sodium, metal halide, mercury vapor or other less efficient light bulbs are used. Four tabs 15 are arranged on the upper housing of the fixture 20 for locating and retaining a dome or reflector. Four tabs (one on each wing) are shown for locating the dome. But more or less tabs can be used. It is also contemplated that a ridge can be incorporated in to the housing to retain the dome without any tabs. The reflector helps to improve the efficiency of the lighting by directing light downward. The reflector comprises an ultra-efficient surface finishes that provide optimum efficiencies. The reflective dome can provide narrow to wide distribution of the light based upon the application and the spacing of the lights. The reflective dome is attached to upper housing 20 that includes an attachment tab for a mounting chain 40 integrated or attached to the upper housing 20 . Vents 29 are shown in this figure.
The vents 29 allow naturally hot air convection to occur and vent out of the fixture. Without the vents in the fixture, the lights within the dome create heat that remains trapped within the fixture and dome. The heat can exceed several hundred degrees and cause melting, distortion, damage and ultimately failure to the fixture and lights.
The housings shown here are in two different sections, but the housing may be a single housing, or may include more than two sections where a lower section 25 includes connection means for the bulb sockets 80 and an upper section 20 that includes mounting for the dome and the hanging attachment for use with a chain 40 or similar hangar to suspend the assembly to the ceiling or a joist. The chain 40 is shown connected through loop 32 that exists on the top of the fixture. The loop 32 allows for a variety of attachment methods including but not limited to chain, wire, cable, or clips that can allow the fixture to permanently or temporarily connected. The upper and lower sections are configured as a junction box or J-box to allow the wiring to be safely enclosed within the two sections. The housings may be constructed from die-cast aluminum, which allows greater heat dissipation and provides greater corrosion resistance. To improve heat dissipation and resistance corrosion, an acrylic powder coat finishes can be applied to both the inside and outside surfaces of the housing. The housing may contain a built-in thermal venting chamber cast into the housing. In the preferred embodiment the housing is molded from a high temperature plastic material. Venting may be included to allow natural cooling of the fixture, and in the embodiment shown the openings 26 exist in the upper housing to allow air to free flow through the lighting fixture. Air movement allows operation of fixtures in higher ambient temperatures. Internal vents 27 are shown in the upper housing to allow air to exit out of the upper housing.
The hanging attachment consists of a simple structural member or loop that a chain can pass under or through to support the entire assembly from the ceiling. The body is a metal, ceramic, plastic or other type base that can support the components and operate in the temperature that the lighting fixture will operate. The body will have more than one female threaded socket 80 . In the preferred embodiment, the threaded female socket is a mogul base, but may be intermittent, medium, candelabra, bayonet or a pin type base. The Mogul base is used because the Mogul base is a very common standard commercial light bulb base that is available from a variety of sources. A number of companies make fluorescent light bulbs with Mogul male threaded bases. A tube may extend from the lower housing 25 . The tube may be straight or bent as a gooseneck. The tube may be made from multiple pieces or may be a bendable or adjustable to change the direction of the light. At the end of the tube a threaded female socket 80 . In the preferred embodiment, five bulbs are used with one bulb located in the center of the fixture and four bulbs are located around the center bulb, where each of the peripheral sockets is located 90° apart. Three bulbs can be located 120° apart. Bulbs can be added that could be spaced equally or grouped on one or more sides. A male socket 90 is shown as part of a standard fluorescent bulb 100 . The replacement bulb has an area for the ballast 105 . The ballast controls power to the fluorescent tubes 110 .
Referring now to FIG. 2 that shows a cross sectional view showing the internal components. The reflective dome 10 is shown in this figure attached to the lighting fixture. The dome is connected to the upper housing 20 with tab(s) 15 . The chain 40 is shown connecting the upper housing 20 with a hook 35 in the ceiling. A single ballast is not required with this fixture because each fluorescent light bulb installed into the fixture includes an integrated ballast. The housing in this figure is shown attached to a rafter 28 . The housing shown provides the structural support to retain the lighting fixture and the dome. The wiring 5 is shown exiting the housing. While the wiring is shown exiting the upper housing for connection to an external junction box, J-box or other connection, the wiring may be brought into the housing from the wiring of the building and connected within the light fixture in its internal junction box, j-box or other connection. The lower portion of the housing has a bulb socket member(s) 80 that has a female light socket. The standard fluorescent light bulb 100 is shown in this figure. The bulb in this figure is a flood or spotlight configuration. The base 90 , of a standard bulb is shown removed from the female threaded socket in the fixture.
Referring now to FIG. 3 that show an electrical diagram of the internal ballast of a fluorescent light bulb. In the US, the ballast is made for 120, 208, 240, 277 or 480 volts. In Canada, ballast options include 120, 277 and 347 volts. In a standard fluorescent bulb, ballast 108 is located with the base of the bulb. The ballast contains a DC pulse generation circuit 106 , and a filtering and voltage regulation portion 107 and a transformer 109 . The tip of the male bulb 43 is connected to the filtering and voltage regulation circuit. The threaded portion of the male bulb is connected to the ground point 42 . The light emitting portion of the bulb 110 may contain one or multiple bulbs 101 102 103 104 . All these components may be found in a standard replacement fluorescent light bulb that can be connected into the replacement fixture.
Referring now to FIG. 4 that show a schematic representation of the wiring within the fixture. When the fixture is wired into an existing building the ballast and the ballast junction box can be removed. The fixture has wiring that connects from the buildings electrical system to the multiple bulb fixtures. The multiple bulbs can be as little as two to as many bulbs are required to provide equivalent light output and voltage drop for the incoming voltage. If the lighting is 277 VAC, multiple 277VAC fluorescent bulbs can be used to achieve equivalent or superior light output. The most cost effective standard replacement bulb is a fluorescent bulb, but other efficient light sources such as LED's or other efficient lighting devices may be used.
The construction of the fixture consists of using electrical connectors that would be used with the existing light electrical system. An electrical connection is made with the corded connector of the fixture. The wires are then connected to a candelabra arrangement of light bulb sockets. The candelabra arrangement consists of at least two bulb sockets that extend from a base structure. The bulbs can extend on fixed, flexible arms or goosenecks. The bulbs can be threaded into the multiple sockets from the base. The sockets can be wired in a series, parallel, or combined series and parallel arrangement that keeps the voltage to a safe level for the lights screwed into the sockets.
Referring now to FIGS. 5 and 6 that shows a bottom view and side view of the lighting fixture respectively with the dome or reflector removed in FIG. 5 . One link of chain 40 is shown in FIG. 6 . This link 40 is shown connected through loop 32 that exists on the top of the fixture. The lower housing of the fixture 25 is shown connecting the male sockets 80 . In FIG. 5 the four wings of the fixture 21 , 22 , 23 and 24 can be seen with the clearance area 26 that allows air movement past the fixture. Eight vents 29 positioned around the fixture allow heat to vent from the fixture to reduce damage from the heat generated by the fluorescent lights. The venting is specifically engineered to keep multiple self-ballasting fluorescent bulbs at a constant cool operating temperature. The cooler operating temperature can significantly extend the life of self-ballasting bulbs. While eight vents are shown within the fixture, multiple other venting options are contemplated that provide a more constant operating temperature. These options may include fabricating the fixture from a wire or steel mesh with multiple holes, or fabricating the fixture from tubes or rods to suspend the dome.
Thus, specific embodiments and applications of a replacement light fixture have been disclosed. It should be apparent, however, to those skilled in the art that many more modifications besides those described are possible without departing from the inventive concepts herein. The inventive subject matter, therefore, is not to be restricted except in the spirit of the appended claims. | A lighting fixture where the lighting fixture does not require a single ballast, but instead uses the ballast incorporated in a plethora of efficient light elements. The lighting fixture is used where high bay or low bay lighting may be used, but incorporates multiple light sources to provide an equivalent light intensity. The multiple light sources can be multiple fluorescent, LED, or other efficient light sources to provide a less expensive cost of operation and installation. The higher efficiency lights could be standard socket type fluorescent bulbs that are easily available. The higher efficiency lights would also create less heat that would further reduce the air conditioning or cooling costs for the buiding. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to an apparatus for removing a surface layer from animal muscular tissue, particularly a skin-including layer from fish fillets, the apparatus comprising a skinning roller driven to rotate and having a circumferential surface designed to grip the material to be treated; a pressure pad provided with a presser surface facing the circumferential surface of the skinning roller, being mounted to be displaced resiliently relative to the circumferential surface of the skinning roller and including a knife receiving pocket; and a blade-like skinning knife received in the pocket.
2. Prior Art
Apparatuses showing these and similar structural features are widely used and are known from printed publications. For example, German Pat. No. 2 049 353 discloses an apparatus, whose structural features correspond to those described above. Use is made therein of a fixed knife blade inserted into the pressure pad, the presser surface being at a limited distance and equidistant from the skinning roller or the circumferentiaI surface thereof and the cutting edge of the skinning knife extending at a distance from the circumferential surface of the skinning roller, which distance corresponds to the thickness of the layer to be severed.
However, as has been found, a satisfactory result could only be obtained when processing the fillets of round fish, this term being used to differentiate from flat fish. The problems encountered in processing fillets of the latter fish type are due to the fact that the skin of such fish is very intimately connected to the muscular substance by a plurality of sinews or similar tendinous ligaments. It was therefore unavoidable to use a drawing cut for processing such fish. In view of this finding and the attempts made to overcome the expensive and maintenance-costly principle of band knife skinners, developments have led towards a system which is characterized by a knife driven to oscillate, as is e.g. disclosed by German Pat. No. 680 720. In this system, the knife is enabled to move from a disengaged and spaced apart basic position into the (closer) working position after the initial portions of the fillet have moved past. Thus, initial fragments are lost and this has to be accepted principally as a production loss.
This deficiency was intended to be removed by the construction in accordance with German Pat. No. 18 10 673, in particular by the embodiment according to FIG. 2 thereof. This construction has an oscillating skinning knife, whose possibilities of pivoting are adjustable and limited in such a way that it remains with a fixedly set spacing with respect to the circumferential surface of the skinning roller. A pressure pad is located below the skinning knife and is at a fixed distance from the circumference of the skinning roller. When using this apparatus, particularly when processing flat fish fillets, a disadvantage arises which is due to the basic concept of this construction. This is revealed in that the tail area splits along the spinal line, so that the skinned fillet receives a dovetail-like appearance, which is considered to be so disadvantageous and an enormous handicap from the quality standpoint that this machine has not been accepted and adopted in this field. The reason for this splitting is the transverse stressing of the fillet during skinning due to the fact that the skinned fillet portions are forced against the oscillating back surface and are accelerated in accordance with the oscillating movement thereof. This effect is supported by that part of the lower surface of the knife which is exposed upstream of the presser surface, the wedge action and the cutting resistance causing an adequately intimate friction between the knife and the fillet, so that the oscillating movement is transferred onto the fillet. In order to reduce this effect by improving the grip of the skin on the skinning roller, the circumferential surface thereof has been provided with a diamond or right-angled knurling. However, apart from a hardly noticeable improvement to the aforementioned effect, this led to a reduction of the reliability of the cutting-start, because now the spacing of the presser surface from the circumferential surface of the skinning roller had to be set at least to the skin thickness of the fillet to be skinned, to ensure that the skin entered underneath the presser surface. However, the resulting gap reduces the pressing action with respect to the skinning roller necessary for a reliable conveying or feeding. In order to enable the necessary close positioning of the presser surface, the circumferential surfaces of the skinning rollers are therefore presently provided with longitudinal grooves, in which the fillet is engaged with its tail end and can thus enter underneath the pressure surface.
Tests carried out with an apparatus according to DE-OS 21 18 164 comprising an oscillating skinning knife which had a reduced moving distance as regards the moving into the working position by the fillet entering into the gap between the skinning roller and the pressure pad also failed to solve the above problem, so that this concept has also not become commercially successful. Apart from the stressing of the fillets as a result of the oscillation, this apparatus led to an above-average unreliability in the initiation stages of the cutting. This is in accordance with the expectations from the aforementioned findings and is mainly due to the fact that the presser surface in its basic position gives the incoming fillet a greater distance from the circumferential surface of the skinning roller than in the working position. Thus, a movement of the pressure pad into the working position only takes place coincidentally, i.e. purely by chance, because for this movement it is necessary that the fillet be adequately entrained by the skinning roller. However, even when the fillet arrives at the knife cutting edge, this entrainment only takes place through friction and pushing engagement of the circumferential surface of the skinning roller roughened by (diamond) knurling or the like. However, this manner of conveying is generally not sufficient to enable the knife to achieve a cutting depth enabling the separated layer to reach the clamping point between the presser surface and the circumferential surface of the skinning roller. However, this is a prerequisite for an adequate torque to become effective on the intermediate gear, in order to bring the knife into the working position close to the circumference and to cause the positive conveying which enables the actual skinning process.
OBJECTS OF THE INVENTION
It is therefore the major object of the present invention to suggest a skinning apparatus enabling both flat and round fish to be skinned in a completely satisfactory manner, i.e. without the above-described problems. It is a further important object of the present invention to perform such skinning whilst obtaining an excellent quality.
SUMMARY OF THE INVENTION
In a skinning apparatus comprising a skinning roller driven to rotate and having a circumferential surface designed to grip the material to be treated, a pressure pad provided with a presser surface facing the circumferential surface of the skinning roller, being mounted displaceably relative to the circumferential surface of the skinning roller against the tension of a spring and including a knife receiving pocket, and a blade-like skinning knife received in said pocket, these objects are achieved in accordance with the present invention in that the knife blade is driven to oscillate and that the receiving pocket is designed as a guide slot guiding the knife blade.
The resulting advantages are in particular that the engagement possibilities of the oscillating surfaces of the knife on the fillet are decisively reduced. As a result of the rather small vibrating or oscillating mass, this concept makes it possible to increase the oscillating frequency and or the amplitude, which leads to a higher average cutting speed, which brings about a further reduction of the transverse forces stressing the fillet.
According to an advantageous development of the invention, adjustable stops are provided for adjusting the basic spacing between the presser surface from the circumferential surface of the skinning roller and/or for limiting the working clearance between these members. Thus, on the one hand, the basic position of the presser surface with respect to the circumferential surface of the skinning roller can be chosen entirely on the basis of the standpoint of reliable cutting and, on the other hand, the lifting movement of the pressure pad can be limited.
For bringing about a reliable guidance of the knife blade and for reducing the area of the knife back-surface coming into contact with the product being skinned, preferably the guide slot receiving the knife blade may, on the one hand, be formed by a back surface of the pressure pad and, on the other hand, by a cover, the latter being provided with at least one guide member which projects through the guide slot and into an elongated hole-like opening in the knife blade.
To permit a simple changing of the knife blade, it may be provided that in the region of its part projecting into the guide slot, each guide member may have chamfers on its sides facing in the oscillating direction and may be arranged to be displaceable against spring tension out of the region of the guide slot, whilst each opening may be aligned parallel to the cutting edge of the knife blade.
In view of the fact that the degree of stressing of the product being skinned is a function of the cutting pressure exerted by the knife blade, it is possible to reduce the same in that each opening is arranged at an inclination with respect to the knife blade cutting edge, so that the blade receives an additional oscillating component directed opposite to the product being skinned. A substantially transverse force-free driving of the knife blade can be obtained in that the drive producing the oscillating movement of the knife blade comprises a crank gear with two synchronously and oppositely moving crank disks, which carry crank pins each connected to a yoke by means of a crank driven rod, which yoke is arranged at one end of the knife blade.
For safeguarding a troublefree start and performance of the skinning process, the circumferential surface of the skinning roller may be provided with longitudinal grooves essentially extending along the generating lines of the circumferential surface.
BRIEF DESCRIPTION OF THE DRAWINGS
Other and further objects of the present invention will be apparent from the following description and claim and are illustrated in the accompanying drawings which by way of illustration schematically show preferred embodiments of the present invention and the principles thereof and what now are considered to be the best modes contemplated for applying these principles. Other embodiments of the invention embodying the same or equivalent principles may be used and structural changes may be made as desired by those skilled in the art without departing from the present invention and the scope of the appended claims. In the drawings
FIG. 1 shows a partial view of the complete apparatus in a simplified axonometric representation;
FIG. 2 shows a partial cross-section through the apparatus in the region of a knife blade guide member;
FIG. 3 shows a partial detail plan view of the inner surface of the cover guiding the knife blade in the region of a guide member;
FIG. 4 shows a partial detail plan view corresponding to FIG. 3 with an inclined guide member;
FIG. 5 shows a section along line V--V of FIG. 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A fish fillet skinning machine comprises a not shown frame, in which a discharge-side deflection roller 2 of an endless supply or feeding belt 1 as well as a skinning roller 3 are mounted, which rollers 2 and 3 are driven to rotate in the same rotational direction. The skinning roller 3 has a circumferential surface 4 provided with longitudinal grooves 5 in a known per se manner. In the region of its discharge side, the circumferential surface 4 of the skinning roller 3 is opposed by a pressure pad or shoe 6 defining a presser surface 7. The latter has a radius of curvature which corresponds essentially to that of the circumferential surface 4 of the skinning roller 3. The pressure pad 6 extends substantially over the entire length of the skinning roller 3 and can be displaced about an axis 8 away from the skinning roller 3 against the tension of a spring 9 and is supported in its basic position by means of an adjustable stop 10 with respect to the width of a clearance or gap between its presser surface 7 and the circumferential surface 4. A pivoting in the opposite direction is limited by a further stop 11. The pressure pad 6 is designed with a back surface 13 as its upward limitation, which back surface 13 extends parallel to the circumferential surface 4 of the skinning roller 3, while it forms an acute angle with the upper end region of the presser surface 7, the top edge 12 of said angle being blunted. The back surface 13 carries a cover 14 with a shoulder, which, together with the back surface 13, forms a guide slot 15 for guiding a knife blade 16. The surface part of the cover 14 which faces the skinning roller 3 is chamfered and, together with the top surface of the guide slot 15, forms a blunted edge 17, which opposes the top edge 12. The knife blade 16 is made from strip steel and its width is dimensioned in such a way that a cutting edge 18 formed thereon projects beyond the edge 17 and/or the top edge 12. In the region of both its ends, the knife blade 16 is provided with one longitudinally extending, elongated hole-like opening 19 each, which is engaged by a guide member 20. This guide member is guided in a corresponding recess 22 in the cover 14 and is held pressed against the back surface 13 of the pressure pad 6 via a pressure pin 24 by means of a leaf spring 23, whilst passing through the knife blade 16. The part of each guide member 20 projecting into the guide slot 15 has, on its sides facing in the oscillating direction, chamfers 21 having at least the thickness of the knife blade 16. One end thereof is secured to a yoke 25, which rests on a not shown sliding surface and is provided with two pins 26. Each one of these is engaged by one crank driven rod 27, respectively, of a double crank gear 28 formed by two synchronously and oppositely driven crank disks 29 carrying crank pins 30 driving said rods.
The function of the apparatus is as follows:
A fillet to be skinned lying on its skin side and with its tail end leading is placed on the circumferential surface 4 of the rotating skinning roller 3 by means of the feeding belt 1 and is conveyed on by the skinning roller. During its entering onto the skinning roller 3 the tail end engages in the longitudinal grooves 5 of the circumferential surface 4 and consequently enters underneath the cutting edge 18 of the knife blade 16. Shortly thereafter, it runs into the gap between the presser surface 7 and the circumferential surface 4 with the already detached parts of the skin, whereby a reliably conveying engagement occurs spontaneously on the cut-free skin. The pressure pad 6 is subject to a lifting force which, after overcoming the tension of the spring 9, effects that the presser surface 7 slides on the inner surface of the tough skin and, by entraining the knife blade 16, brings its cutting edge 18 into a distance from the circumferential surface 4 corresponding to the thickness of the skin to be severed.
In order to permit a more economical use of the knife blade 16, it can be designed as a reversible blade, in that both its longitudinal edges are provided with a cutting edge. For reversing and/or changing the knife blade 16, it is merely necessary to release the connection between the same and the yoke 25, whereupon the knife blade 16 may then be drawn out of the guide slot 15 in the direction of the crank gear 28 by displacing the guide members 20 via chamfers 21. Another knife blade 16 may be inserted correspondingly until the guide members 20 engage and/or lock in the openings 19 and may then be connected to the yoke 25. | An apparatus for skinning fish includes a pressure pad carrying an oscillating knife blade and defining a presser surface which faces the circumferential surface of a skinning roller, the pressure pad being mounted to yield against spring force. The oscillating knife blade is guided in a pocket formed in the pressure pad. This arrangement makes it possible to skin fish fillets without any splitting of the tail portion. | 0 |
BACKGROUD OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an apparatus for monitoring the progress of membrane fouling that occurs on pores as well as on the surface of a membrane by means of varaitions of zeta potential (ζ) of a hollow-fiber membrane measured according to time passage of filtration of a suspension, wherein colloid particles, biopolymers and other inorganic particles are dispersed, and the method thereof. Moreover, the present invention also relates to a method to identify the effect of concentration polarization layer and cake layer which can vary according to the axial position of a hollow-fiber and the subsequent developing progress of a membrane fouling by measuring the position-dependent zeta potential of the hollow-fiber membrane.
[0003] 2. Description of the Related Art
[0004] In conventional methods, measurements of streaming potential of a membrane have been implemented by employing either a flat-plate type or a tubular membrane and the related studies have been largely restricted to charged property of membrane surface or electrokinetic phenomena. Therefore, there is a need for the development of a technology that can interpret the fouling progress of a given membrane via changes in zeta potential according to time passage of filtration as well as measurement of streaming potential of a hollow-fiber membrane.
[0005] Zeta potential, being defined based on electrostatic and electrokinetic principles, is known to provide useful real-time information on the surface property and the interaction between membrane and particles in actual operational situations and physicochemical conditions without incurring structural change of membrane or disturbance of flow condition. That is, zeta potential can not only provide information on electrostatic field when the membrane surface is in contact with a flowing solution but can be also an important physical quantity related to a criterion of membrane fouling resulted from adsorption or deposition of particles thus determining the property and performance of a membrane.
[0006] In the present invention, electrodes were installed both inside and outside of an inlet and an outlet of a hollow-fiber membrane, respectively, to measure the streaming potential. The difference between streaming potentials perceived simultaneously at these electrodes were used to evaluate the value of zeta potential.
[0007] The conventional apparatus and methods related to the present invention are described hereunder.
[0008] Ricq et al. [ Journal of Membrane Science, 114(1996), 27-38] studied the properties of the initial virgin and the fouled membranes after filtration of a tubular inorganic membrane by measuring zeta potential and analyzing permeate flux. They installed platinum electrodes such that they penetrated the internal channel of a membrane and measured the streaming potential difference and permeate flux, however, the membrane used was not a hollow-fiber membrane but a tubular membrane and also the measurements were not made at various positions but at the inlet.
[0009] Japanese Pat. No. 62-47545 discloses a method to measure streaming potential as a way to identify the property of zeta potential inside of a hollow-shaped cylindrical tube. This method relates to the measurement of streaming potential of the internal wall of a cylindrical tube, a kind of a pipe, unlike the apparatus of the present invention which relates to a hollow-fiber having membrane pores. This method enables to measure the zeta potential of the internal wall since a given solution can flow through the cyclindrical tube, however, it cannot measure the property of membrane pores located on the radial wall of a hollow-fiber as shown in the present invention.
[0010] Japanese Published Pat. Appln. No. 11-197472 discloses a method to analyze fouling in a given separation membrane as a way to identify the fouling of a reverse osmosis membrane. This method enables to identify the fouling of a flat-plate reverse osmosis membrane by comparing the zeta potentials on membrane surface before and after the fouling and also sets up the washing conditions of the membrane. However, this method is only related to the application of the result of zeta potential to the observation of membrane fouling and is not related to the method or the apparatus of measuring streaming potential. The example 2 of the present invention also shows that the zeta potential changes according to the membrane fouling.
[0011] Szymczyk et al. conducted a study on zeta potential according to the change in ionic concentration of electrolytes by installing an Ag/AgCl electrode at each given point on both an upper and a lower region of plane inorganic membrane [ Journal of Membrane Science, 134(1997), 59-66].
[0012] Japanese Published Pat. Appln. No. 8-101158 discloses a method to measure streaming potential of porous materials and Japanese Published Pat. Appln. No. 10-38836 discloses an apparatus to measure streaming potential.
[0013] These methods and apparatus, being designed for porous materials, cannot be applied to a hollow-fiber membrane and also cannot be used in measuring zeta potentials at local positions.
SUMMARY OF THE INVENTION
[0014] It is essential to provide fine installments of electrodes which carry out measurements of minute streaming potential difference in order to obtain the membrane zeta potential. A hollow-fiber membrane is not advantageous in that it has a very narrow internal diameter unlike a flat-plate or a tubular membrane, and this results in difficulty when installing internal electrodes and also becomes liable to damage the hollow-fiber or disturb the liquid flow. Moreover, the cross-flow filtration enables to generate a concentration polarization layer as the filtration is run along the axial direction and the continued permeation results in change in particle concentrations as well as the pressure drop, according to the axial position.
[0015] The present invention installed electrodes both inside and outside of an inlet and an outlet of a hollow-fiber membrane, respectively, and also provided a device to sense the minute change of streaming potential difference generated by the minute pressure difference across the membrane pores.
[0016] The present invention succeeded in monitoring the progress of membrane fouling over time by evaluating the zeta potential of a hollow-fiber membrane by continuously measuring the streaming potential in two given positions according to time passage of filtration of a given suspension.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] [0017]FIG. 1 is a diagram that shows a concentration polarization layer as well as a cake(or gel) layer generated inside a hollow-fiber membrane by cross-flow filtration and the resulting difference in local streaming potential.
[0018] [0018]FIG. 2 is a schematic diagram of the apparatus of the present invention that enables to measure the difference in local streaming potential of a hollow-fiber membrane by cross-flow filtration.
[0019] [0019]FIG. 3 shows an exploded view of a hollow-fiber membrane module used in the apparatus of the present invention measuring streaming potential difference.
[0020] [0020]FIG. 4 is a graph that shows zeta potential at an inlet and an outlet of a hollow-fiber membrane measured according to the change of pH under a constant ion concentration of a symmetric monovalent electrolyte.
[0021] [0021]FIG. 5 is a graph that shows the change in zeta potential at an inlet and an outlet of a hollow-fiber membrane measured according to the time passage under a constant pH as well as a constant ion concentration of a symmetric monovalent electrolyte while performing filtration of a biopolymer protein solution.
[Code Explanation] 1. thermostated feed tank 2. solvent delivery pump 3. conductance meter 4. pH meter 5. connecting part of membrane module 6.main body of 7. clamping part of membrane module membrane module 8. internal electrode of a hollow-fiber membrane 9. external electrode of a hollow-fiber membrane 10. hollow-fiber membrane 11. minute flow- 12. multi-channel digital multi-meter control valve 13. computer 14. pressure gauge 15. pressure gauge connecting aperture 16. sealing ring 17. epoxy resin potting
DETAILED DESCRIPTION OF THE INVENTION
[0022] The present invention relates to an apparatus and the method of measuring local streaming potential for monitoring the progress of membrane fouling over time in the course of filtration with hollow-fiber membrane.
[0023] To achieve the above-mentioned goal, the inventors of the present invention prepared an apparatus which comprises a feed tank to reserve feed solution in a state of colloidal suspension; a membrane module with several hollow-fibers as well as a connecting part and electrodes to measure streaming potential; a means to deliver feed solution from the feed tank to the inside of the hollow-fiber membranes; a means to measure physical properties of said feed solution; a means to measure the transmembrane pressure differences between the inside and the outside of a hollow-fiber at both an inlet and an outlet of a membrane module and a means to control the transmembrane pressure differences; a means to simultaneously measure and record the differences in local streaming potential being obtained from the above electrodes; and a means to obtain the value of zeta potential (ζ) of a hollow-fiber membrane by using the physical properties, transmembrane pressure difference and the difference in streaming potential.
[0024] This invention will be better understood with the following figures.
[0025] [0025]FIG. 1 shows a diagram that depicts a concentration polarization layer as well as a cake layer generated inside a hollow-fiber membrane due to cross-flow filtration and the resulting local streaming potential difference.
[0026] [0026]FIG. 2 is a schematic diagram of the apparatus of the present invention that can measure local streaming potential difference of a hollow-fiber membrane due to cross-flow filtration. As shown in FIG. 2, the apparatus of measuring streaming potential according to the present invention comprises a thermostated feed tank 1 to reserve feed solution in a state of colloidal suspension; two means 3 and 4 to measure physical properties of said feed solution; the body of membrane module 6 equipped with electrodes 8 and 9 to measure streaming potential difference as well as a hollow-fiber membrane 10 ; a fine flow-control valve 11 to adjust transmembrane pressure difference present between the inside and outside of the hollow-fiber 10 ; a pressure gauge 14 that measures the transmembrane pressure difference both at an inlet and an outlet of a membrane module; connecting parts 5 and 7 which are parts of membrane module that link between membrane module and flow channel; two means 12 and 13 to display and record data being obtained from the above-mentioned measuring means; and a means to calculate the value of zeta potential (ζ) of the hollow-fiber membrane 10 .
[0027] [0027]FIG. 3 is an exploded view of the connecting part between membrane module and the flow channel, which shows a connecting part 15 , electrodes 8 and 9 to measure streaming potential difference, a clamping part 14 of membrane module, a sealing ring 16 to prevent fluid leakage at the connecting part, the hollow-fiber membrane 10 wherein the actual filtration takes place, a potting region 17 cured by epoxy resin to separate the permeate from the feed solution, and the body 6 of cylindrical membrane module containing the above-mentioned parts.
[0028] The relative cooperation of the respective parts of the membrane module is set forth hereunder.
[0029] An Ag/AgCl (or platinum) wire-type electrode 8 with 0.25 mm in diameter, which takes about 6% of the internal cross-sectional area of a hollow-fiber, is installed inside the hollow-fiber membrane 10 , where the actual filtration of feed solution takes place, to allow undisturbed liquid flow while a spiral electrode 9 made of the same material is installed on the corresponding external positions of the hollow-fiber so that it can sense the minute streaming potential difference according to the minute pressure difference.
[0030] The permeation of suspension due to pressure difference results in change in ionic fluid flow and charge distribution within a solution in the hollow-fiber membrane pores. Therefore, it generates a difference in streaming potential between the upper and the lower regions of membrane pores and the difference can be detected by a pair of electrodes consisting of an internal electrode 8 and the external electrode 9 . The internal electrode 8 is inserted into the inside of the hollow-fiber membrane mounted on the cylindrical membrane module by means of the clamping part 7 of the membrane module, and the varying values detected in each electrode are measured by using multi-channel digital multi-meter 12 .
[0031] The method of measuring streaming potential can be further delineated as follows. A given solution is supplied from the thermostated feed tank 1 of feed solution through the membrane module connecting part 5 to the hollow-fiber membrane 10 by means of a solvent delivery pump 2 , and subsequently the respective conductance and pH are measured by using a conductance meter 3 and a pH meter 4 .
[0032] Transmembrane pressure can be properly adjusted up to 0.3% of the maximum flow rate by using a minute flow-control valve 11 installed at an outlet of a concentrate and pressure difference can be measured by using a pressure gauge 14 .
[0033] The streaming potential (ΔV) generated between the upper and the lower regions of membrane pores at a given position of the hollow-fiber membrane is measured by using multi-channel digital multi-meter 12 via Ag/AgCl electrodes 8 and 9 installed inside and outside of the given position, respectively, and recorded in a computer 13 .
[0034] The zeta potential can be obtained by plugging the values of streaming potential ΔV, generated from a given pressure difference ΔP, dielectric constant ε, conductivity of a solution λ, viscosity of a solution η into the following Helmholtz-Smoluchowski equation (I).
Δ V Δ P = ɛζ λη ( I )
[0035] This invention is explained in more detail based on the following examples, however, they should not be construed as limiting the scope of this invention.
EXAMPLE 1
[0036] A given solution can have various pH values in the course of filtration of the hollow-fiber membrane. In measuring zeta potential according to pH change, it is usually quite essential to measure an isoelectric point. After installing several hollow-fiber ultrafiltration membranes (Model PM100, Internal diameter; 1.0 mm, KOCH Membrane System Inc., MA, USA) made of polysulfonate having asymmetric membrane pores, pH was modified in the presence of 1.0 mM aqueous solution of potassium chloride, a symmetric monovalent electrolyte. Then, streaming potential was measured at two different positions, at an inlet and at an outlet of a hollow-fiber membrane, under the pressure difference of less than 0.4 kg f /cm 2 across the membrane pores.
[0037] The results of the application of the above equation (I) were reliable when the zeta potential difference of the membrane was less than 5% between two directions, wherein one of the flow directions of permeate was directed outside from the inside of the hollow-fiber membrane while the other is directed in the opposite way. As the pH increased, according to the results, the zeta potential of a hollow-fiber membrane changed from negative to positive and the isoelectric point was formed around pH 9.4.
[0038] The absolute value of zeta potential at an outlet of a hollow-fiber membrane was lower than that at an inlet and this is ascribed to the fact that the permeation of a given solution is continued while the flow of feed solution is directed to the axial direction of the hollow-fiber membrane and thus the flow rate becomes to decrease as it goes to the outlet and also the amount of the charged ions become depleted. The results are shown in the FIG. 4.
EXAMPLE 2
[0039] As a way to monitor the change in zeta potential of a given solution according to time passage of filtration, wherein particles are suspended in feed solution, several hollow-fiber ultrafiltration membranes (Model PM100, Internal diameter; 1.0 mm, KOCH Membrane System Inc., MA, USA) made of polysulfonate having asymmetric membrane pores were installed on membrane modules. Then, an aqueous solution containing a biopolymer of 300 ppm of bovine serum albumin (BSA) was filtered and then streaming potential was measured at two different positions both at an inlet and at an outlet of a hollow-fiber membrane. The pressure difference across the membrane pores was less than 0.2 kg f /cm 2 , the concentration of potassium chloride as an electrolyte was 1.0 mM and the pH of the solution was 6.0. It is already known that, at pH 6.0, the pores of a hollow-fiber membrane are positively charged as in the example 1 while the surface of BSA is negatively charged.
[0040] The FIG. 5 shows the result of filtration progress, which reveals that the absolute value of the zeta potential was higher at the inlet than that at the outlet and this is consistent with the example 1. The zeta potential changed from positive to negative about 20 min after the start of the filtration and this indicates that the properties of the charged membrane must have been changed during the filtration process due to the adsorption or deposition of BSA particles, which were negatively charged at pH 6.0, onto the surface of the membrane. The absolute value of zeta potential decreases as the filtration proceeds and even a faster decreasing rate at the outlet; this appears to be due to the weakened electrokinetic flow resulted from the narrowed membrane pores due to the continued adsorption or deposition of BSA particles.
Comparative Example 1
[0041] The zeta potentials according to filtration progress and the location of a membrane were measured by using the apparatus in the example 1 as shown in the examples 1, 2, and FIGS. 4 and 5, however, there are no reports on these results in the prior art.
[0042] As mentioned above, the present invention provides a novel apparatus and a novel method to obtain zeta potential influenced by a concentration polarization layer and a cake (or gel) layer which can vary according to the axial position in a given hollow-fiber membrane. The ability to obtain the zeta potential in the present invention in the course of filtration of a given suspension with a hollow-fiber according to time passage can also help to identify the characteristics of physicochemical interactions on membrane pores and on membrane surface as well as to monitor the progress of membrane fouling. These are essential in studying the downstream for the highly efficient filtration with a hollow-fiber membrane. Further, the present invention can also provide critical data that can be used in studying the electrokinetic properties, charged characteristics, hydrophilicity and the level of substituted functional as well as ionic groups according to modifications. | The present invention relates to an apparatus for monitoring the progress of membrane fouling that occurs on pores as well as on the surface of a membrane by means of variations of zeta potential (ζ) of a hollow-fiber membrane according to time passage of filtration of a suspension, wherein colloid particles, biopolymers and other inorganic particles are dispersed, and the method thereof. Moreover, the present invention also relates to a method to identify the effect of concentration polarization layer and cake layer which can vary according to the axial position of a hollow-fiber and the developing progress of a membrane fouling by measuring the position-dependent zeta potential of the hollow-fiber membrane. | 8 |
TECHNICAL FIELD
This invention relates generally to the production of ultra high purity oxygen and more particularly to the production of ultra high purity oxygen from a gaseous feed stream.
BACKGROUND ART
Commercial grade high purity oxygen has a nominal purity of 99.5 percent. Generally commercial grade high purity oxygen is produced by the well known cryogenic fractional distillation of air, most often using a stacked double column arrangement. The commercially available high purity oxygen is suitable for use in a great many applications.
Commercial grade high purity oxygen contains a small amount of impurities. The impurities include both light impurities having a vapor pressure greater than oxygen, and heavy impurities having a vapor pressure less than oxygen. Occasionally oxygen is required which has significantly less impurities than the commercially available high purity oxygen. In these instances, high purity oxygen has heretofore been upgraded to ultra high purity oxygen by means of catalytic combustion.
The electronics industry requires the use of ultra high purity oxygen for many applications. However, the conventional catalytic combustion method for producing ultra high purity oxygen is not suitable because of the consequent production of particulates generated from the granulated catalyst.
It is desirable therefore to have a process and apparatus to produce ultra high purity oxygen without need for the use of catalytic combustion.
Accordingly, it is an object of this invention to produce ultra high purity oxygen without need for the use of catalytic combustion.
It is a further object of this invention to produce ultra high purity oxygen by the upgrading of high purity oxygen produced by the cryogenic fractional distillation of air.
SUMMARY OF THE INVENTION
The above and other objects which will become apparent to those skilled in the art upon a reading of this disclosure are attained by the present invention one aspect of which is:
A process to produce ultra high purity oxygen from a gaseous feed comprising:
(a) introducing gaseous feed containing oxygen, light impurities and heavy impurities into an absorbing column;
(b) passing gaseous feed up the absorbing column and absorbing heavy impurities from ascending gas into descending liquid;
(c) condensing resulting gas, passing a first liquid portion thereof into a stripping column and passing a second portion thereof down the absorbing column as said descending liquid;
(d) passing first liquid portion down the stripping column and stripping light impurities from the downflowing liquid into upflowing vapor to produce ultra high purity oxygen liquid;
(e) vaporizing ultra high purity oxygen liquid and passing resulting vapor up the stripping column as said upflowing vapor; and
(f) recovering product ultra high purity oxygen.
Another aspect of this invention is:
Apparatus to produce ultra high purity oxygen from a gaseous feed comprising:
(a) an absorbing column having feed introduction means;
(b) a stripping column;
(c) heat exchanger means;
(d) means to pass vapor from the upper portion of the absorbing column to the heat exchanger means;
(e) means to pass liquid from the heat exchanger means to the upper portion of the stripping column; and
(f) means to recover fluid from the stripping column.
The term, "column", as used herein means a distillation of fractionation column or zone, i.e., a contacting column or zone wherein liquid and vapor phases are countercurrently contacted to effect separation of a fluid mixture, as for example, by contacting of the vapor and liquid phases on a series of vertically spaced trays or plates mounted within the column or alternatively, on packing elements with which the column is filled. For a further discussion of distillation columns see the Chemical Engineers' Handbook. Fifth Edition, edited by R. H. Perry and C. H. Chilton, McGraw-Hill Book Company, New York, Section 13, "Distillation" B. D. Smith et al, page 13-3 The Continuous Distillation Process. The term, double column is used to mean a higher pressure column having its upper end in heat exchange relation with the lower end of a lower pressure column. A further discussion of double columns appears in Ruheman "The Separation of Gases" Oxford University Press, 1949, Chapter VII, Commercial Air Separation.
The term "indirect heat exchange", as used herein means the bringing of two fluid streams into heat exchange relation without any physical contact or intermixing of the fluids with each other.
As used herein, the term "tray" means a contacting stage, which is not necessarily an equilibrium stage, and may mean other contacting apparatus such as packing having a separation capability equivalent to one tray.
As used herein, the term "equilibrium stage" means a vapor-liquid contactinq stage whereby the vapor and liquid leaving the stage are in mass transfer equilibrium, e.g. a tray having 100 percent efficiency or a packing element height equivalent to one theoretical plate (HETP).
As used herein, the term "stripping column" means a column operated with sufficient vapor upflow relative to liquid downflow to achieve separation of a volatile component such as argon from the liquid into the vapor in which the volatile component such as argon becomes progressively richer upwardly.
As used herein, the term "absorbing column" means a column operated with sufficient liquid downflow relative to vapor upflow to achieve separation of a less volatile component such as methane from the vapor into the liquid in which the less volatile component such as methane becomes progressively richer downwardly.
As used herein, the term "reboiler" means a heat exchange device which generates column upflow vapor from column bottom liquid.
As used herein, the term "condenser" means a heat exchange device which generates column downflow liquid from column top vapor.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic flow diagram of one preferred embodiment of the invention wherein the invention is employed as an addition to a cryogenic distillation air separation plant.
FIG. 2 is a schematic flow diagram of a particularly preferred embodiment of the invention wherein the invention is employed standing alone utilizing liquid oxygen addition refrigeration or liquid nitrogen addition refrigeration.
FIG. 3 is a schematic flow diagram of one way to carry out certain heat exchange operations of the embodiment of FIG. 2.
FIG. 4 is a schematic flow diagram of another way to carry out certain heat exchange operations of the embodiment of FIG. 2.
DETAILED DESCRIPTION
The invention will be discussed in detail with reference to the drawings.
Referring now to FIG. 1, gaseous feed 200 is introduced into the lower portion of absorbing column 20. Feed gas 200 is comprised primarily of oxygen, generally at a concentration within the range of from 90.0 to 99.9 percent. Typically feed gas 200 is commercial grade high purity oxygen having a concentration of about 99.5 percent oxygen. Feed gas 200 also contains light impurities, such as argon, nitrogen, hydrogen and helium, which have a higher vapor pressure or volatility than oxygen, and heavy impurities such as krypton, xenon and hydrocarbons, which have a lower vapor pressure or volatility than oxygen.
In the embodiment of FIG. 1, feed gas 200 is taken directly from a cryogenic air separation plant. In the case where the cryogenic air separation plant is of the double column type, preferably the feed gas is taken from the bottom of the upper column.
The feed gas is passed up absorbing column 20 and heavy impurities are absorbed from the ascending gas into descending or wash liquid. As used herein "impurities" means both one specie of impurity as well as more than one specie. When a double column cryogenic air separation plant is employed with the embodiment illustrated in FIG. 1, it is preferred that resulting wash liquid 202 be passed to the oxygen side of the double column main condenser.
Resulting washed gas 203 is passed from the upper portion of column 20, such as by conduit means, to heat exchanger 22 wherein it is condensed by indirect heat exchange. Heat exchanger 22 could be outside absorbing column 20, as shown in FIG. 1, or could be within a structure which also houses the absorbing column. Heat exchanger 22 is driven by any suitable fluid 204. Preferably fluid 204 is liquid taken from the bottom of the higher pressure column of a double column air separation plant and the resulting vaporized fluid 205 is returned to the double column in the midsection of the lower pressure column.
A first portion 210 of resulting liquid 206 from heat exchanger 22 is passed through conduit means into the upper portion of stripping column 21 while a second portion 201 is passed down absorbing column 20 as the descending liquid.
Liquid 210 is passed down stripping column 21 and light impurities are stripped from the downflowing liquid into upflowing vapor which exits stripping column 21 as gaseous stream 212. Stream 212 is commercial grade high purity oxygen which is essentially free of hydrocarbons and other heavy impurities. As such, stream 212 may be recovered as a secondary product.
Ultra high purity oxygen liquid produced within stripping column 21 is vaporized by indirect heat exchange by reboiler 29 and the resulting vapor is passed up stripping column 21 as the upflowing vapor. Reboiler 29 is driven by any suitable fluid 207. Preferably fluid 207 is vapor taken from the upper portion of the higher pressure column of a double column air separation plant and the resulting condensed fluid 208 is returned to the double column as reflux liquid.
Product ultra high purity oxygen may be recovered from stripping column 21 as gaseous stream 211 after vaporization by reboiler 29 and/or may be recovered as liquid 213 before vaporization. When producing gaseous oxygen, reboiler 29 vaporizes substantially all of the liquid which downflows to the bottom of column 21. Some liquid may be removed through stream 213 as drainage if a significant amount of product is recovered as gas in order to ensure safe operation of reboiler 29.
FIG. 2 illustrates a particularly preferred embodiment of the invention which may be employed independent from a cryogenic air separation plant. The numerals in FIG. 2 correspond to those of FIG. 1 for the common elements.
Referring now to FIG. 2, gaseous oxygen 70 is compressed by compressor 24, cooled by cooler 40 and further cooled by indirect heat exchange in heat exchanger 25 against return streams. Resulting gaseous feed 200 is introduced into absorbing column 20 wherein it ascends and is washed of heavy impurities by descending liquid.
Absorbing column 20 is less sensitive to pressure than is stripping column 21. This lower sensitivity can be put to advantage by operating absorbing column 20 at a higher pressure than that at which stripping column 21 is operated. This enables the use of dual heat exchangers for the condensation of the washed gas, and furthermore enables one of these heat exchangers to be the reboiler of stripping column 21.
Referring back now to FIG. 2, portion 80 of washed gas 71 is passed through conduit means to heat exchanger 72 wherein it is condensed. Heat exchanger 72 is the bottom reboiler of stripping column 21 and is driven by the condensing washed gas so as to vaporize ultra high purity oxygen stripping column bottoms. First portion 210 of resulting liquid 81 from heat exchanger 72 is passed through valve 73 and into the upper portion of stripping column 21 while second portion 201 is passed down absorbing column 20 as the descending liquid. Wash liquid 202 is passed out of absorbing column 20, expanded through valve 74, vaporized in side condenser 26 and the resulting vaporized stream 46 is warmed by passage through heat exchanger 25 and passed out of the process through valve 48 as stream 50.
Portion 75 of washed gas 71 is passed to side condenser 26 wherein it is condensed and is removed as condensed stream 82. Stream 82 is combined with stream 81 and the resulting stream is divided into streams 210 and 201.
To compensate for system heat leakage, liquid oxygen 45 is passed through side condenser 26 and out of side condenser 26 as part of stream 46. Stream 52 is a drain utilized for contaminant control in side condenser 26.
As previously mentioned, liquid 210 is expanded through valve 73 and passed into and down stripping column 21. Light impurities are stripped from the downflowing liquid into upflowing vapor which exits stripping column 21 as gaseous stream 212. Stream 212 is warmed by passage through heat exchanger 25 and passed out of the process through valve 49 as stream 51.
Depending upon the value of hydrocarbon-free stream 51, streams 46 and 212 can be mixed ahead of heat exchanger 25 to reduce heat exchanger 25 to a two pass heat exchanger. Also in this embodiment, additional liquid nitrogen or other refrigeration can be utilized either directly to condense oxygen vapor from the top of the absorbing column, such as by inserting a liquid nitrogen cooling heat exchange means into side condenser 26 as illustrated in FIG. 3, or indirectly through an auxiliary oxygen condenser 27 to condense a small portion 212A of hydrocarbon free oxygen vapor stream 212 for insertion as stream 45 into side condenser 26 as illustrated in FIG. 4.
The numerals in FIG. 3 correspond to those of FIG. 2 for the common elements. Referring now to FIG. 3, liquid nitrogen addition stream 55 is vaporized to condense a portion of stream 75 from the top of absorbing column 20. Vaporized nitrogen stream 56 is warmed and exits via an extra nitrogen pass provided in heat exchanger 25.
Referring now to FIG. 4, an auxiliary oxygen condenser 27 is provided to generate liquid oxygen addition stream 45 from a portion 212A of stream 212. Liquid nitrogen stream 55 is vaporized by the indirect heat exchange with stream 212A and vaporized nitrogen stream 56 is warmed and exits via an extra nitrogen pass provided in heat exchanger 25.
The embodiments illustrated in FIG. 3 and 4 which utilize liquid nitrogen addition for purposes of heat balance and to condense oxygen are preferred ways of achieving this heat balance and condensation. However, those skilled in the art will recognize that there are many other ways to carry this out within the scope of the process of this invention. For example, it would be possible to combine heat exchangers 26 and 72 into one multipass single unit. One pass would condense stream 71, another would vaporize stream 202, another would vaporize the liquid from the bottom of column 21, and another would vaporize the liquid nitrogen addition. Such a single multipass heat exchanger would require liquid recirculation or liquid drains from the oxygen rich passes to ensure safe operation of the heat exchanger unit.
Ultra high purity oxygen liquid produced within stripping column 21 is vaporized by indirect heat exchange by reboiler 72 and the resulting vapor is passed up stripping column 21 as the upflowing vapor. As previously mentioned, reboiler 72 is driven by washed vapor from the absorbing column. Product ultra high purity oxygen may be recovered from stripping column 21 as gas 211 after vaporization by reboiler 72 and/or may be recovered as liquid 213 before the vaporization. Reboiler 72 vaporizes substantially all of the liquid which downflows to the bottom of column 21 other than the product liquid 213. Some small amount of liquid may be removed through stream 213 if a significant amount of product is recovered in gaseous form via 211 in order to ensure safe operation of reboiler 72.
The absorbing column useful with the invention operates at a pressure within the range of from 10.3 to 103 pounds per square inch absolute (psia) (0.7 to 7.0 atmospheres). The stripping column useful with the invention operates at a pressure within the range of from 10.3 to 73.5 psia (0.7 to 5.0 atmospheres) and preferably within the range of from 1 to 4 atmospheres.
Typically the product ultra high purity oxygen of this invention will have an oxygen purity of at least 99.999 percent and may have a purity of up to 99.99999 percent.
The absorbing column is operated such that methane absorbing factor A preferably exceeds 1.0 and most preferably exceeds 1.1. Methane absorbing factor A=1/kv where 1 is the liquid molar flow in the absorbing column, v is the vapor molar flow in the absorbing column, and k is the ratio of the mole fraction of methane impurity in the gas phase and the mole fraction of methane impurity in the liquid phase at thermodynamic equilibrium. When operated in this manner, the absorbing column serves to reduce the concentration of methane from that of stream 200 to that of stream 210 by about three orders of magnitude. Since methane is the most volatile of the heavy impurities, all other heavy impurities will be reduced in concentration by operation of the absorbing column by an even greater factor.
The stripping column is operated such that argon stripping factor S preferably exceeds 1.0 and most preferably exceeds 1.1. Argon stripping factor S=KV/L where V is the vapor molar flow in the stripping column, L is the liquid molar flow in the stripping column, and K is the ratio of the mole fraction of argon impurity in the gas phase and the mole fraction of argon impurity in the liquid phase at thermodynamic equilibrium. When operated in this manner, the stripping column serves to reduce the concentration of argon from that of stream 210 to that of the product ultra high purity oxygen by about three orders of magnitude. Since argon is the least volatile of the light impurities, all other light impurities will be reduced in concentration by operation of stripping column by an even greater factor.
Either of the absorbing column or the stripping column, or both, may be comprised of a series of vertically spaced trays or of column packing. Those skilled in the mass transfer art are familiar with the many types of trays and column packing available and no further detailed discussion is necessary here.
The results of a computer simulation of the invention carried out with the embodiment illustrated in FIG. 1 are presented in Table 1. The stream numbers in Table 1 correspond to those of FIG. 1. The abbreviation CFH stands for cubic foot per hour at standard conditions of 1 atmosphere and 70 degrees Fahrenheit, ° K. stands for degrees Kelvin, and PPM stands for parts per million. The stripping column operated at an argon stripping factor of 1.2 and had 34 equilibrium stages or theoretical trays and the absorbing column operated at a methane absorbing factor of 1.2 and had 31 equilibrium stages or theoretical trays. The invention was operated as an addition to a double column air separation plant. As can be seen, the argon impurity is reduced from 4000 to 5 ppm and the methane impurity is reduced from 10 to 0.04 ppm. Furthermore, as can be seen, stream 212 which is substantially free of hydrocarbons and other heavy impurities may be recovered at a flow rate of about one half that of the incoming feed. Since the product ultra high purity oxygen is recovered as liquid, gas stream 211 is not used.
TABLE 1______________________________________Flow, Pressure, Temper- Impurity, PPMStream No. CFH PSIA ature °K. Argon Methane______________________________________200-gas 7740 25.5 95.9 4000 10201-liquid 2830 23.1 94.8 4776 0.01202-liquid 2830 25.5 95.9 2653 27.3210-liquid 4910 23.1 94.8 4776 0.01211-gas 0 25.5 95.9 -- --212-gas 3910 23.1 94.8 5997 0.003213-liquid 1000 25.5 95.9 5 0.04______________________________________
A major advantage of the embodiment of the invention such as is illustrated in FIG. 1 is that there is no need for additional oxygen compression or additional heat pump compression as would also be possible if feed gaseous oxygen is available at pressure for the FIG. 2 embodiment. In such a case, compressor system components 24 and 40 shown in FIG. 2 would be omitted.
The results of a computer simulation of the invention carried out with the embodiment illustrated in FIG. 2 are presented in Table 2. The stream numbers in Table 2 correspond to those of FIG. 2. The stripping column operated at an argon stripping factor of 1.2 and had 35 equilibrium stages or theoretical trays and the absorbing column operated at a methane absorbing factor of 1.2 and had 31 equilibrium stages or theoretical trays. As can be seen, the argon impurity is reduced from 4000 to 5 ppm and the methane impurity is reduced from 10 to 0.04 ppm.
TABLE 2______________________________________Flow, Pressure, Temper- Impurity, PPMStream No. CFH PSIA ature °K. Argon Methane______________________________________70-gas 7900 37 300 4000 10200-gas 7900 33.5 99 4000 10202-liquid 2990 33 98.8 2703 26.4210-liquid 4910 30.5 97.9 4790 0.01213-liquid 1000 25.5 95.9 5 0.0445-liquid 1190 23.1 94.8 4000 1046-gas 4180 23.1 94.8 3073 21.750-gas 4180 20 292 3073 21.7212-gas 3910 23.1 94.8 6014 0.00351-gas 3910 20 292 6014 0.003______________________________________
Although the process and apparatus of this invention have been described in detail with reference to certain preferred embodiments, those skilled in the art will recognize that there are other embodiments of this invention within the spirit and scope of the claims. | A process and apparatus to produce ultra high purity oxygen comprising serially oriented absorbing and stripping columns having defined flow stream relationships. | 5 |
STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable
CROSS-REFERENCES TO RELATED APPLICATIONS
Not applicable
REFERENCE TO A “SEQUENCE LISTING,” A TABLE, OR A COMPUTER PROGRAM LISTING APPENDIX SUBMITTED ON A COMPACT DISK.
Not applicable
BACKGROUND OF THE INVENTION
This invention relates to digital packet telecommunications, and particularly to management of flow of data, that is, the volume of data per unit time across heterogeneous network boundaries. It is particularly useful in a digitally-switched packet telecommunications environment normally not subject to data flow rate control. The present invention is intended to work in an environment having a metered-release of acknowledgements and a window control mechanism.
This invention represents an augmentation of the capabilities disclosed in the work of Robert Packer, as for example described in U.S. Pat. Nos. 6,018,516; 5,802,106; 6,038,216; 6,046,980; 6,205,120; 6,285,658; 6,298,041; and 6,115,357). The Packer packet flow rate control mechanisms taught therein controlled size of the sliding window, amount of acknowledged data and timing of acknowledgement delivery.
The ubiquitous TCP/IP protocol suite intentionally omits explicity supervision of the rate of data transport over the various media which comprise a network. While there are certain perceived advantages, this characteristic of TCP/IP has the consequence of juxtaposing very high-speed packet flows and very low-speed packet flows in potential conflict for network resources, which results in inefficiencies. Certain pathological loading conditions can result in instability, overload and data transfer stoppage. Therefore, it is desirable to provide some mechanism to optimize efficiency of data transfer while minimizing the risk of data loss. Data flow rate capacity information is a key factor for use in resource allocation decisions.
The technology of interest is based largely on the TCP/IP protocol suite, where IP, or Internet Protocol, is the network layer protocol and TCP, or Transmission Control Protocol, is the transport layer protocol. At the network level, IP provides a “datagram” delivery service. By contrast, TCP builds a transport level service over the datagram service to provide guaranteed, sequential delivery of a byte stream between two IP hosts.
Conventional TCP flow control mechanisms operate exclusively at the end stations to limit the rate at which TCP endpoints emit data. However, TCP lacks explicit data rate control. In fact, until the work of Packer, there was no concept of coordination of data rates among multiple flows.
The basic TCP flow control mechanism is a sliding window superimposed on a range of bytes beyond the last explicitly-acknowledge byte. Its sliding operation limits the amount of unacknowledge transmissible data that a TCP endpoint can emit.
The sliding window flow control mechanism works in conjunction with the Retransmit Timeout Mechanism (RTO), which is a timeout to prompt a retransmission of unacknowledged data. The timeout length is based on a running average of the Round Trip Time (RTT) for acknowledgment receipt, i.e., if an acknowledgment is not received within (typically) the smoothed RTT+4* means deviation, then packet loss is inferred and the data pending acknowledgment is retransmitted.
Data rate flow control mechanisms which are operative end-to-end without explicit data rate control draw a strong inference of congestion from packet loss (inferred, typically, by RTO). TCP end systems, for example, will ‘back-off’, i.e., inhibit transmission in increasing multiples of the base RTT average as a reaction to consecutive packet loss.
While TCP rate control has significant advantages, there are certain conditions where the response time needed to adjust rate control mechanisms is less than can be provided by Packer flow rate control techniques.
SUMMARY OF THE INVENTION
According to the invention, in a packet-based communication system where acknowledgment packets are employed in the control of the flow rate of packets, packet flow rate control techniques are enhanced by the interactive and early invocation of packet queuing to control short flows of packets and to eliminate overshoot of a targeted flow rate. Packet queuing according to the invention may involve the scheduled release of packets in accordance with flow policies (priorities) to achieve a preselected outgoing target flow rate. In a specific embodiment of the invention, packets that arrive from a data source at the beginning of a flow before rate control is effective, the packets are forwarded by metering them out at the allocated bandwidth below the bandwidth capacity of the channel based on an expected capacity of the channel. The queuing of packets terminates and the queue is emptied as the feedback-based rate control mechanism using acknowledgments begins to moderate the rate of packet release from the data source. Packet rate control uses window size (TCP window size), acknowledgment rate, and number of bytes acknowledged. The combination of controlled packet queuing and network flow rate control with appropriate mechanisms for favoring one over the other improves the efficiency of data transmission.
The invention will be better understood by reference to the following detailed description in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is first flow chart of operation of an integrated packet rate control mechanism according to the invention.
FIG. 2 is a second flow chart of operation of an augmented packet rate control mechanism in FIG. 1 according to the invention.
FIG. 3 is a third flow chart of operation of a normal rate control and sizing mechanism in FIG. 1 according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1 , a flow chart is shown of overall or integrated system operation of a controller at a portal in the flow path between an arbitrary data source and an arbitrary data destination according to the invention. The invention is explained in the context of Transmission Control Protocol (TCP), which is a well-known transmission protocol used on the Internet. However, in general any network protocol or network application which employs a feedback mechanism to moderate bandwidth allocated to a source can be rate controlled through an implementation of this mechanism. Network transport protocols that fall into this category include AppleTalk ADSP, AppleTalk ATP, some sub-protocols of SNA, SNA/IP, and RTP/IP. Some applications with explicit timing feedback, such as Real Audio over UDP, can also be controlled with a specific implementation of the described mechanism.
In the protocol, a network packet arrives at the controller (Step A) and is immediately tested to determine if it is a new flow (Step B). If not, the packet is passed through, where it is subsequently check to determine if this flow is controlled or not (Step C). (A control block for this flow may be retrieved at this point to facilitate control.) It not, the packet is transmitted on in the network (Step D). The controller is thus transparent to the packet.
If the flow (Step B) is a new flow, then the controller sets up a local control block with flow information for this new flow, such as source and destination IP addresses and TCP ports of the flow, as well as the state of the flow (e.g., time of receipt of packet, time of last packet received, ACK number, Sequence number, last ACKs, and window size) (Step E), and then the controller checks to see if flow is to be controlled (Step C).
If flow is to be controlled, the controller determines whether it is a TCP flow (Step F). If not, then the flow control is passed on to other control mechanisms appropriate to the flow type (Step G), and which are not a part of this specific embodiment.
If it is a TCP flow, then the controller checks to determine if a TCP SYN (synchronization) flag or RST (reset) flag set (Step H), in which case, the packet is passed to the network. Otherwise, the packet is tested to determine whether it contains data with a new ACK number (an ACK which has not been received before) (Step I). If not, it tested for data (Step J) and if not, it is passed on for normal TCP ACK processing (Step K, FIG. 3 ).
If the packet contains both data and new ACK information, then the data and the ACK are separated (Step L). this is done as follows. A new packet is created with no data, and the new ACK information is copied into the new packet. This new packet is forwarded for normal TCP ACK processing (Step K). The data packet is stripped of the new ACK information (the acknowledgment number in the TCP is set back to the last acknowledgment number that was forwarded in this direction), and the packet, which now contains only data, is forwarded to TCP data processing (Step M, FIG. 2 ). By separating the data from the ACK, the data can be forwarded as soon as possible without regard to the timing of the forwarded ACK packets that are metering the sender's data transmission rate.
Referring to FIG. 2 , with the environment set up to take advantage of the invention, the local control block for the flow is augmented and updated (Step N) by recording the highest sequence number (SEQ) received, checking for missing data according to missing sequence numbers, and recording the time of arrival of the packet at the controller. Then in Step O, a new estimate of the flow's data rate is made. This is done by updating an Exponentially Weighted Moving Average (EWMA) with the latest flow rate measurement. The latest flow rate measurement is the number of bytes in the packet received divided by the interval since the receipt of the last received packet. This value is the measured flow rate. Thereafter the controller determines the target data rate (Step P) by making a new estimate of the flow's potential rate (whether to increase or decrease), requesting bandwidth from the distribution mechanism (not shown), and receiving from the bandwidth distribution mechanism an assignment of bandwidth or target rate in bytes per second. The target rate is acquired on every incoming packet, since the target rate information is used in subsequent control steps.
The state of the initial packet in a flow is State 0 (zero) of possible states 0 , 1 and 2 . The states indicate whether a queue is on buildup, draindown or whether the queuing mechanism is finished. This queuing process is typically not used after an initial period related to the beginning of a new flow or a restart of a flow after a pause.
If the tested packet has achieved a state equal to 2 (Step Q), then there will be no queuing, and the packet is transmitted without undue delay (Step R). If the state is zero or 1, then the controller tests to see if there is already a packet queued for this flow (Step S). If not, then the controller tests to determined whether the packet's inbound arrival rate exceeds the assigned target rate (Step T) (as determined by Step P). If not, the packet is transmitted (Step R). If its rate exceeds the target rate, then it is scheduled for delayed release (Step U), and it is released as scheduled.
If there is a data packet already queued for flow (Step S), then the state flag is again tested for State 0 or 1 , to determine the state of the queue (Step V). If the state is zero (queue buildup), then the controller tests to see if the number of packets in the queue is greater than a trigger level, as selected by the operator (Step W). (In TCP where the target rate is not more than an order of magnitude different than the incoming rate, a queue of 2–4 is expected to be sufficient). If the queue is not “full,” the packet is added to the queue (Step X), and the packet is dealt with as part of the scheduled release of the queue (the next transmission of a packet in the previous scheduling performed in of Step U). However, if the packet count exceeds the trigger, the state is set to State 1 (Step Y) before the packet is added to the queue (Step X).
If the state is State 1 (Not State= 0 , Step V), the queue is in draindown state, whether or not it is being emptied. The controller checks to see if the number of packets in the queue has fallen below a draindown trigger level (Step Z). The draindown trigger level may be different than the buildup trigger level. If not, then the packet is added to the queue (Step X). Otherwise, the state is set to 2 (Step AA) before adding the packet to the queue. State 2 indicates that the queuing is done. Packets are released from the queue in due course through the scheduling of transmission.
Referring now to FIG. 3 , the mechanism for rate control with Acknowledgment is illustrated. This process takes over from the queuing mechanism, which is the initial rate control mechanism, after the decisions of the controller outlined in FIG. 1 are completed. The ACK packet (Step K) prompts the updating of the ACK information of the flow's control block (Step AB) and tests to determine whether there is an ACK which has been queued (Step AC). If there is already an ACK for this flow that has been scheduled for future release, then the current ACK is simply deleted (Step AD), and the controllers wait for the next timed ACK transmission or release. If there is not an ACK in the system, this ACK packet is used to determine data rates and ACK rates (Step AE). This is done by dividing the number of bytes acknowledged between the time of receipt of the current ACK and time of receipt of a previous ACK. This rate may be averaged over several ACK times using the EWMA technique mentioned previously.
The ACK rate is then tested (Step AF). If the ACK rate does not exceed the assigned ACK rate as specified by the bandwidth manager (Step T, which is based on data flow rate), the window size is modified to be consistent with prior window sizes (Step AG) and the ACK is transmitted to the data source (Step AH). If the ACK rate does exceed the assigned ACK rate, then, since there is no scheduled ACK, the controller modifies the ACK to be consistent with the data rate assigned to the flow, the ACK may be modified by changing the number of bytes acknowledged by the packet (never sending an ACK that is less than previously sent ACKs), or it may reduce the advertised window size (which can be done by holding one edge of the window constant, since reducing the window from previous packets without advancing the acknowledgment number is a violation of the TCP protocol specification) (Step AI). The ACK may be and often is delayed in time. This time delay is useful in conjunction with ACK modifications to induce the data sender to send further data packets at the assigned data rate. Then the controller modifies the ACK packet according to the prior calculations (Step AJ), and schedules the ACK packet for later transmission (Step AK). After the scheduled delay, the ACK packet is transmitted (Step AL) and the controller checks to see if all bytes which have been acknowledged by the receiver have been forwarded to the sender (Step AM). If so, the process is done. Otherwise, the ACK is recycled (Step AN) and new determinations are made of delay, byte count and window size (Step AI) in according with the acknowledgment-based rate control mechanism.
The combination of initial queuing of packets and Acknowledgment-based rate control provides an effective mechanism for introduction of new flows in a bandwidth limited packet transmission environment, where speeds need to be controlled. It is most useful in an environment where fast and slow rates must be merged, and it inhibits undesired effects manifest in traffic speed oscillation.
The invention has been explained with reference to specific embodiments. Other embodiments will be evident to those of ordinary skill in the art. It is therefore not intended that the invention be limited, except as indicated by the appended claims. | Packet flow rate control techniques are enhanced by the interactive and early invocation of packet queuing to control short flows of packets and to eliminate undershoot and overshoot of a targeted flow rate. Packet queuing involves the scheduled release of packets in accordance with flow policies (priorities) to achieve a preselected outgoing target flow rate. The combination of controlled packet queuing and packet flow rate control with appropriate mechanisms for favoring one over the other improves the efficiency of data transmission. | 7 |
GOVERNMENT SUPPORT
This invention was at least partially supported by the Office of Naval Research, under Grant Numbers N00014-94-1-0963, N00014-94-1-087, and N00014-96-1-5024.
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation of provisional application number 60/024,407, Method for Measuring Nitrite and Nitrate in Aqueous Solution, filed Aug. 22, 1996, now abandoned.
FIELD OF THE INVENTION
The present invention relates to the measurement of nutrients such as nitrite and nitrate in aqueous media, and particularly to the measurement of such nutrients in those parts of natural water bodies (e.g., the upper layers of the ocean) where the concentrations of such nutrients are relatively low (i.e., in the tens of nanomoles per liter or less).
INTRODUCTION/SUMMARY OF INVENTION
Nitrate and nitrite are very important nutrients to phytoplankton, the single-celled plants that are the dominant plants in the ocean, which is the largest ecosystem on Earth. Such nutrients are depleted by phytoplankton near the ocean's surface to very low levels: nanomolar or less. Yet, phytoplankton continue to grow in these regions, and chemists, utilizing techniques based on 40-year-old chemical methods, cannot detect the detailed distributions of the nutrients that are critical to phytoplankton growth. The variations in these nutrients are often a few tens of nanomoles per liter, while conventional detection limits are 200 nanomolar or higher.
According to the present invention, the measurement of nitrite in anaqueous medium comprises the steps of:
a. treating a sample of the aqueous medium with a reagent that acidifies the sample, converts nitrite in the sample to nitrosium ion, and reacts with the nitrosium ion to yield a chemical species which fluoresces, and
b. fluorometrically analyzing the resulting sample/reagent mixture to determine the concentration of such chemical species in the mixture, and thus to determine the concentration of nitrite in the sample.
In the practice of the present invention, the reagent is preferably an acidified solution in which the active ingredient is aniline.
Further, according to the present invention, the measurement of nitrate in the aqueous medium comprises treating a first aliquot of the aqueous medium in the manner described above to determine its nitrite concentration, treating a second aliquot (e.g. either sequentially or in parallel with the treatment of the first aliquot) to reduce the nitrate in the second aliquot to nitrite and measuring the resulting nitrite in the modified second aliquot in the manner described above, and using those two measurements to determine the concentration of nitrate in the second aliquot by difference.
Still further, the method of the present invention contemplates different ways of reacting the nitrosium ion with reagent, depending primarily on whether there is expected to be dissolved organic matter in the sample. Where there is no or little dissolved organic matter in the sample, the flow injection method described in Example 1 can be used. However, where dissolved organic matter is present, or is expected to be present, in the sample, the reverse flow injection method, described in Example 2 is preferred. Reverse flow injection enables a baseline fluorescence value to be established from fluorescent dissolved organic matter in the sample and an additional fluorescence value to be determined for the sample due to chemical species yielded by the reaction of nitrosium ion with the reagent, thereby enabling determination of the concentration of nitrite in the sample from the difference between the baseline and additional fluorescence values.
Further features of the present invention will become apparent from the following detailed description and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic illustration of a system for use in performing a method according to one embodiment of the present invention, using flow injection techniques;
FIG. 2 illustrates fluorescent nitrite analysis of samples, prepared according to the principles of the present invention, and using flow injection techniques;
FIG. 3 illustrates data believed to validate the method of the present invention by demonstrating its linearity in the nanomolar concentration range;
FIG. 4 is a schematic illustration of a system for use in performing a method according to another embodiment of the present invention, using reverse flow injection techniques;
FIG. 5 illustrates fluorescent nitrite analysis of samples, prepared according to the principles of the present invention, using reverse flow injection techniques, and which samples include sea water samples with dissolved organic matter; and
FIG. 6 presents a comparison between chemiluminescence and fluorescent aniline methods for nitrite analysis.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As described, the present invention relates to a method of determining the concentrations of nitrite and nitrate in aqueous media, in a manner that is designed for near real time sampling rates, and to measure relatively low (e.g., nanomolar) concentrations of such nutrients in an aqueous medium such as seawater. The following examples describe two embodiments of the method of the present invention, utilizing flow injection techniques (Example 1) and reverse flow injection techniques (Example 2).
EXAMPLE 1 (FLOW INJECTION)
The following example, illustrated in FIGS. 1-3, demonstrates the application of fluorescence-based measuring techniques involving a reaction between dissolved nitrite and an aromatic primary amine that permits intensive, detailed, and high-sensitivity surveys of both nitrite and nitrate in the upper layers of the ocean or other natural water bodies.
With the technique described in this example, which is applied utilizing an automated approach called flow-injection, nitrate and nitrite concentration down to less than 5 nanomolar can be detected while rates of sampling and analysis remain similar to those of conventional methods (e.g., about 20 determinations per hour), which is approximately the rate at which natural waters are commonly sampled down through a water column.
Theory
Nitrite can be converted to nitrosium ion by acidifying the solution. Subsequently, a diazonium ion forms via reaction of the nitrosium ion with a primary amine. An exemplary amine selected was aniline due to its simple structure, which includes a benzene ring. The product is the benzene-diazonium ion. The conjugated double bond structure of the benzene molecule contains π-bonds, which contain π-electrons that readily fluoresce. In addition, the benzene-diazonium ion contains two π-bonds in the triple bond between the two nitrogen atoms. Thus the formation of the benzene-diazonium ion from the reaction of aniline and nitrite in acidic media yields a strong change in the fluorescence due to the formation of more π-bonds.
Nitrate can be reduced quantitatively to nitrite by passing it through a copper-activated cadmium column. Once reduced to nitrite, nitrate can be analyzed utilizing the same reaction as that for nitrite. The efficiency of the reduction depends upon the flow rate through the reduction column, the bed volume of the reduction column, and the pH of the solution.
The fluorescent wavelength of excitation for any molecule can be related to its absorbance spectrum. Some of the ultraviolet and visible wavelengths at which a given molecule exhibit absorbance maxima are the wavelengths that promote electrons within a conjugated double bond structure to the π* state. This promotion is limited to shorter wavelengths due to the energy necessary to promote electrons between the ground and excited states in such a system. Once the wavelength of maximum absorbance of the product of the reaction of an analyte, such as nitrite, with reagent, such as aniline, has been identified, that wavelength is used as the excitation wavelength for the product ion, and the wavelength of maximum emission is then determined in the same fashion as the wavelength of maximum absorbance in absorbance spectroscopy. The emission wavelength is always longer than the excitation wavelength due to loss of energy via radiationless conversions within the molecule when the electron falls to the lowest excited state. Therefore, the preferred wavelengths for detection of the nitrite-derived benzene-diazonium ion formation are obtained in the following manner. Two spectra are determined: (1) the excitation spectrum of the 1:1 (V:V) mixture of deionized water (DIW) and 50 μL of aniline dissolved in 1 μL 10% HCl, which provides the background absorbance spectrum and (2) the excitation spectrum resulting from the reaction of a 1:1 (V:V) mixture of 1000 nM nitrite in DIW and 50 μL of aniline dissolved in 1 L 10% HCl. The difference between these two spectra yields the absorbance spectrum of the reaction. The wavelength of maximum absorbance is then used for the excitation wavelength and the fluorescent emission spectra of the two different solutions are scanned and subtracted. These experiments yield the optimal wavelengths for this fluorescence based chemistry as defined below.
Reagents are degassed for two reasons. Due to the short period of time the reaction mixture is within the analytical manifold, heating is required to increase the yield of the reaction. This heating can create bubbles of dissolved gases that, if not removed, will interfere with the fluorescence signal. Also, degassing of the 10% HCl solution prior to the addition of aniline prevents baseline drift associated with the oxidation of aniline by oxygen dissolved in the solvent.
Reagents
The deionized (DI) water for all purposes is prepared by polishing DI water with a Millipore Milli-Q RG system. The aniline reagent is composed of 1 L of degassed 10% HCl and 50 μL of aniline (from Alfa Asear). The carrier solution is degassed polished DI water. The buffer solution for nitrate reduction consists of 85.0 grams of ammonium chloride, NH 4 Cl (reagent grade, Aldrich Chemical Co.) diluted to approximately 950 mL with DI water. This solution is then degassed. Following the degassing, the solution is adjusted to pH 8.5 with ammonium hydroxide and diluted to 1 L with polished DI. The solutions are degassed by bubbling helium through the solutions via polytetrafluoroethylene (PTFE) tubes inserted into the flasks for thirty minutes.
System Setup
Solution delivery is accomplished via an Ismatec sixteen-channel peristaltic pump (Cole Parmer model no. H-78001-32) operated at 25% of full speed, utilizing calibrated platinum-cured silicon autoanalysis tubing to carry the solutions. The nominal ratings for tubing inside the pump were 1.60 mL/min for the sample or standard, 0.80 mL/min for the DI carrier and aniline reagent, and 0.23 mL/min for the NH 4 Cl buffer. These rates correspond to flow rates of 3.40, 1.80. and 0.40 mL/min at 25% of pump speed, respectively. All other tubing downstream of the pump consisted of 0.8 mm I.D. PTFE. Two position Cheminert sample injection valves 12 with micro electric actuators (Valco Instrument Company Inc. model no. C12-3116EH) and 1 mL sample loops 14 were used to introduce samples and standards into the analytical manifolds 16A,16B of the system.
As seen in FIG. 1, the nitrite analytical manifold 16A is shown at the lower portion of the system, and the nitrate analytical manifold 16B is shown at the upper portion. In the nitrite analytical manifold 16A, 400 cm of PTFE tubing follow after the point 18A where the aniline reagent is injected. The tubing is coiled inside a Technicon heater 20 (model no. B-273-27), which is reengineered with two channels of the appropriate bore PTFE tubing, and set at 70° C. In the nitrate analytical manifold 16B, 8 cm of PTFE tubing come after the buffer injection point into the carrier stream 18B, followed by a 90 degree flowpath 3-port valve 22 (Hamilton 86728). This valve, and another valve of the same type 24 just downstream of the cadmium columns 26, are used for isolation of the cadmium columns when the instrument is not being used to analyze samples. 16 cm of PTFE tubing connect the flowpath valve 22 to three 24-inch cadmium columns 26 (Irama 165-0301-24) followed by 16 cm of PTFE tubing and the second flowpath valve 24. 14.5 cm of PTFE tubing connect that flowpath valve to the aniline reagent injection point 28. The solution then flows through 400 cm of PTFE tubing in the heater 20.
It should be noted that, in both the nitrate and nitrite analytical manifolds, the analyte/reagent stream leaving the heater enters a 5-cm section of high-density microporous PTFE tubing. The purpose of this tubing is to allow the escape of any bubbles that may form in the analyte/reagent stream while it is being heated. Then, in both manifolds, the outputs of the microporous tubing are connected to Hitachi L-7480 fluorescence detectors equipped with 12 μL flowcells. The detectors are set up using the following parameters: excitation, 220 nm; emission, 295 nm; time constant, 8 seconds; PMT, 1.
Analytical Processing
Samples and standards are introduced into the analytical manifolds by linking an A.I. Scientific XYZ autosampler (AIM 1250) to the manifold. In order to synchronize the injections with the sample or standard selection, the contact closure relays on the autosampler are used to signal the injection valve. Concord 2.0 software provided with the autosampler controls the process. An Ascentia 950N 90 MHz Pentium laptop computer controls the instrument and collects and analyzes data simultaneously.
The analog output of the detectors is digitized with a 24 bit DT2804 A/D board, which is installed in an AST docking station linked to the Ascentia computer. The digitized signal is then analyzed via Chromperfect 2.1 chromatography software (Justice Innovations), which determines the peak heights of the injected samples in a Windows® environment (FIG. 2). The multitasking environment of Windows® is required so that the autosampler could be controlled by the separate Concord 2.0 program, while data are being collected and analyzed. The peak heights of the standards are corrected for analyte present in the solvent (Low Nutrient Seawater, also referred to as LNSW) that is used to match the matrix of the samples by subtracting the average peak height of two nonspiked LNSW samples (peaks 12 and 13 in FIG. 2) from the peaks for spiked LNSW standards (peaks 4-11 in FIG. 2). The instrument standardization involves the injection of three seawater solutions to obtain equilibrium (FIG. 2, peaks 1-3), followed by duplicates of spiked LNSW samples corresponding to the following concentrations: 1000; 500; 250; 100; 0 nM nitrite (FIG. 2, peaks 4, 5; 6, 7; 8, 9; 10, 11; and 12,13; respectively). Directly following these injections, samples are injected (FIG. 2, peaks 14-23). The peak heights for all injections are imported into a Quattro Pro spreadsheet program in which a linear regression is generated for the corrected standards (FIG. 3). The function generated by this regression is then used to calculate the nitrite concentrations present in the samples.
Similar processing can be used to determine the concentration of nitrate in the sample. By reducing nitrate to additional nitrite and determining the overall nitrite concentration, the concentration of additional nitrite (due to nitrate) is thereby determined by difference.
Additional Comments
All samples of aqueous media are drawn into acid-washed, oven-dried 27 mL headspace vials (Fisher 03-340-71 A) sealed with 20 mm PTFE/silicon septa (Supelco 2-7374) and 20 mm aluminum crimps. In order to sample these sealed vials, the autosampler was adapted to use a stainless steel 12-inch 18-gauge Luer hub needle (Kontes H 90018-0012). These adaptations include an additional set screw for the probe and an acrylic plate with precisely machined holes that hold the sample vials in place when the probe exited the sample vial. In order to maintain a consistent flow of sample through the sample loop the sealed vials must be vented. This venting ss done by machining an aluminum block with two holes corresponding to the outer diameter of the 18-gauge needle and a stainless steel 22-gauge vent needle. The vent needle is attached just below the autosampler probe via a set screw on the 18-gauge needle, while the 22-gauge needle is fastened with another set screw. All connections within the manifold are made with zero dead volume flange fittings using 1/4-28 thread connectors, tefzel tees, and Luer-lock connections (for the autoanalysis tubing).
Linearity of the flow injection method of the present invention is considered by the applicants to be excellent over the concentration range from 0 to 1000 nanomolar (0-1 micromolar). FIG. 3 shows a typical standard curve and standardization that demonstrates this linearity (correlation coefficient=0.999572). A high degree of linearity is important for the minimization of analytical error.
EXAMPLE 2 (REVERSE FLOW INJECTION)
Theory
The basic theory underlying the measurement of the concentration of nitrite in an aqueous medium is the same as described in Example 1. However, this example uses reverse flow injection analysis (rFIA) methodology to enable correction for dissolved organic matter (DOM) background fluorescence in the aqueous medium.
Reverse flow injection analysis methodology (rFIA) involves the injection of a precise quantity of reagent into a sample stream, which acts as the carrier stream. All the fundamental principles of flow injection analysis apply to rFIA, namely reproducible timing, injection, and dispersion. rFIA is used to correct for the DOM background fluorescence in natural samples. Once a sample's natural fluorescence achieves a plateau, the reagent is injected to develop the fluorescent signal from the nitrite present. The initial plateau height of the sample provides the natural background fluorescence, which can be subtracted from the overall sample fluorescence as the DOM matrix blank. Deionized water (DIW) is used as the baseline into which the aniline reagent is injected in order to determine the contribution of the aniline reagent to all fluorescence signals; the height of these peaks are averaged to obtain the reagent blank.
Due to the short period of time the reaction mixture is within the analytical manifold, heating is required to increase the yield of the reaction. Since dissolved gases tend to come out of solution at higher temperature, reagents are preferably degassed to reduce the likelihood of bubble formation during heating.
Reagents
Deionized water (DIW) for all purposes was prepared by polishing tap water with a Milli-Q RG system. The aniline reagent is composed of 1 L of degassed 10% HCl and 500 μl, of aniline (Alfa Asear). The wash solution is degassed polished DIW. The buffer solution for nitrate reduction consists of 8.0 grams of imidazole (reagent-grade Aldrich Chemical Co) plus 45.0 mL of NH 4 Cl/CuSO 4 solution diluted to 1 L with polished DIW. The NH 4 Cl/CuSO 4 solution consists of 250 g NH 4 Cl in 1 L DIW plus 2.5 mL of 0.08M CuSO 4 . Cadmium for nitrate reduction is prepared from coarse ground cadmium for reduction reactors (CB/M manufacturing) by washing the cadmium three times with each of the following solutions: acetone, DI, 10% HCl, DI, NH 4 Cl. The cadmium is then copperized by immersion in 0.08M CuSO 4 . The remaining solution is decanted, and the cadmium is stored in the imidazole buffer. The solutions are degassed by bubbling helium through the solutions via polytetrafluorethylene (PTFE or Teflon) tubes inserted into the flasks for thirty minutes.
System Setup
Solution delivery (FIG. 4) is accomplished with an Ismatec 16-channel peristaltic pump 40 (Cole Parmer H-78001-32) operated at 25% of full speed, utilizing calibrated platinum cured silicon autoanalysis tubing to carry the solutions. The nominal pump tube ratings were: (1) 1.60 mL/min for the autosampler-to-sample selection-valve priming tube; (2) 0.80 mL/min for the sample, standard, or DIW wash and for the 10% HCl solution; (3) 0.23 mL/min for the aniline reagent; and (4) 0.03 mL/min for the imidazole buffer. At 25% of pump speed these rates correspond to flow rates of 3.40, 1.80, 0.40 , and 0.09 mL/min, respectively. All other tubing consists of 0.8 mm I.D. PTFE. Two-position six-port Cheminert injection valves 42A, 42B with micro electric actuators (Valco Instrument Company Inc. C 12-311 6EH) and 0.15 mL sample loops 44A, 44B (no additional tubing between ports 3 and 6) are used to introduce the aniline reagent into the analytical manifolds 48A, 48B. An additional two-position six-port Cheminert valve 46 is configured as a sample stream selection valve. This allows the switching of samples without introduction of an air bubble as the sample probe shifts between sample vials (i. e., when the sample is not selected, a DIW wash is).
The nitrite analytical manifold 48A consists of the tee 50, at which the 10% HCl reagent is injected into the sample stream connected directly to the aniline-reagent injection valve 42A. The outlet of the injection valve 42A is connected to 400 cm of PTFE tubing. This tubing is coiled inside a Technicon heater 54 (B-273-27), which is reengineered with two channels of the appropriate-bore PTFE tubing and set at 70° C. After heating, the analyte stream enters a 5-cm section of high-density microporous PTFE tubing (International Polymer Engineering); this arrangement removes any bubbles that might form as a result of the decrease in solubility of dissolved gases with the increase in temperature of the analyte stream. The nitrate analytical manifold 48B consists of 4 cm of PTFE tubing after the buffer injection point 52 into the sample stream, followed by a 90° flowpath 3-port PTFE valve 56 (Omnifit). This valve, and another valve 58 of the same type just downstream of the cadmium column 60, are used for isolation of the cadmium column when the instrument is not being used to analyze samples. The cadmium column 60 is constructed of a 13.1 cm length of hollow acrylic rod with a 1.272 cm o.d. and a 0.491 cm i.d (corresponding to a bed volume of approximately 2.2 mL) packed with coarse copperized cadmium powder (MC/B manufacturing) prepared as described above. Four cm of PTFE tubing connected the second flowpath valve 58 to the point, or tee 62, where the 10% HCl reagent is injected into the sample stream. The tee 62* where the 10% HCl was injected is connected directly to the aniline reagent injection valve 42B. The outlet of the injection valve 42B is connected to 400 cm of PTFE tubing in the heater 54. Following the heater, the sample stream flows through another 5-cm piece of high-density microporous PTFE tubing. The outlets of the microporous PTFE tubing in both manifolds are connected to Hitachi L-7480 fluorescence detectors equipped with 12 μL flowcells. The detectors are set up using the following parameters: 220 nm excitation, 295 nm emission, 8 second time constant, 1 PMT.
Samples and standards are introduced into the analytical manifolds by linking an A.I. Scientific XYZ autosampler (AIM 1250) to the manifolds. The contact closure relays on the autosampler are used to signal the injection valve actuators in order to synchronize the injections with the sample or standard selection. This is accomplished using the Concord software provided with the autosampler. At time equal to 0 seconds for a sample, the reagent injection valves 42A, 42B are set to the load position and the sample selection valve is set to the DIW wash position. At time equal to 60 seconds the sample selection valve is switched to the sample position (the 60 second period provides the wash between samples). At time equal to 195 seconds the reagent injection valves are switched to the inject position. The 135 sec period between the beginning of the sample and the injection of the reagent allows for the sample background fluorescence to achieve a plateau. Total time per sample is 200 seconds.
The analog output of the PMT detectors is digitized with a 24-bit DT2804 A/D board. The A/D board was installed in an AST docking station linked to a Ascentia 950N 90 MHz Pentium laptop computer, which controlls the instrument, collects data, and analyzes data simultaneously. Each digitized signal is then recorded and displayed in real time using Chromperfect 2.1 for Windows® chromatography software (Justice Innovations). The multitasking environment of Windows® allows the autosampler to be controlled by a separate program, Concord 2.0, provided with the autosampler. Raw data for each analyte channel is imported into Peak Fit software 4.1. The peak heights for reagent blanks, sample background, and analyte concentration are determined via the Gaussian Deconvolution method. The parameters applied to achieve this are:
Baseline: linear/progressive, total percentage=1%;
Deconvolution: width=0.04805, standard deviation, filter=92.9;
Peak Type: spectroscopy, Voigt amplitude approximation;
Auto Scan: amplitude %=20%, vary widths, vary shape.
The autoscan peak height determinations are then exported to a spreadsheet, where all calculations were done.
To prevent initial contamination of the aqueous medium being analyzed, samples are quickly drawn into acid-washed, oven-dried, 27 mL headspace vials (Fisher 03-340-71A) sealed with 20 mm PTFE/silicon septa (Supelco 2-7374) and 20 mm aluminum crimps. In order to extract aliquots from these sealed vials, the autosampler is modified to use a stainless steel, 12 inch, 18-gauge Luer hub needle (Kontes H90018-0012). These modifications include an additional set screw for the probe and an acrylic plate with precisely machined holes that hold the sample vials in place when the probe exits the sample vial. In order to maintain a consistent flow of sample through the sample loop, the sealed vials have to be vented. This venting is done by machining an aluminum block with two holes corresponding to the outer diameter of the 18-gauge needle and a stainless steel 22-gauge vent-needle. The vent-needle assembly is attached just below the autosampler probe with a set screw on the 18-gauge needle; the 22-gauge needle is fastened with another set screw. All connections within the manifold are made with zero-dead-volume flange fittings with 1/4-28 thread connectors, tefzel tees, and Luer-lock connections for the autoanalysis tubing.
As seen from FIG. 5, the peak heights of the samples and standards are corrected for reagent blank fluorescence by averaging the peak heights of two reagent injections into DIW (which has no DOM). The samples and standards are also corrected for background fluorescence due to any DOM present by subtracting the plateau height of each peak prior to aniline reagent injection. The standards are then corrected for analyte present in the solvent (Low Nutrient Seawater or LNSW) used to match the matrix of the samples by subtracting the average peak height of two nonspiked LNSW samples. The instrument standardization involves the introduction of two DIW samples, followed by duplicates of spiked LNSW samples corresponding to the following concentrations: 1000, 500, 250, 100, 0 nM nitrite. Directly following the injections of these solutions, actual seawater samples are introduced into the nitrite and nitrate manifolds.
Interferences
As mentioned, it was found that dissolved organic matter (DOM) in seawater fluoresces at the wavelengths specified above. In order to correct for this false signal, rFIA is implemented. In rFIA the sample acts as the carrier, while a fixed volume of reagent is injected. This allows a background signal to be established prior to the injection of the reagent, which automatically identifies and permits the removal of the contribution of the fluorescence from DOM. Since organic leachates from tygon pump tubing positively interfere with the benzenediazonium fluorescence, platinum-cured silicon pump tubes are used to carry all solutions that enter the analytical manifold.
Additional Comments
From the results of many standardizations, the applicants believe that the linearity of the fluorescent aniline reverse-flow-injection method for nitrite in aqueous media is equivalent to the linearity of the fluorescent aniline flow-injection method for nitrite in aqueous media shown in FIG. 3.
A well-established, albeit more cumbersome, technique for measuring nitrite (or nitrate) in aqueous media utilizes the chemiluminescence of the nitric oxide (NO) formed from nitrite (or nitrate) dissolved in such media. The applicants believe that the detection limits of the fluorescent flow-injection and reverse-flow injection technique of the present invention for nitrite (<5 nanomolar) are close to the nitrite detection limits of chemiluminescent techniques. FIG. 6 shows a comparison of nitrite concentrations in water samples measured by the fluorescent technique to nitrite concentrations in the same samples measured by a chemiluminescent technique. Note that the slope of the least-squares line through the data points is very close to unity (0.9996), that the correlation coefficient (0.9956) is also close to unity, and that the intercept of the line is approximately equal to the detection limit of the method. These features are all consistent with the claim that the two techniques are comparable.
Summary
Thus, as shown by the foregoing description, applicants have provided new and useful techniques for determining the concentration of nutrients, i.e., nitrites and nitrates in an aqueous medium such as seawater. With the foregoing disclosure in mind, it is believed the manner in which the principles of the present invention can be applied to determine the concentration of nutrients in other aqueous media will be apparent to those of skill in the art. | A method is provided for measuring the concentration of nutrients such as nitrite and nitrate in aqueous media, e.g. the upper layers of the ocean where the concentrations of such nutrients are relatively low (i.e. in the tens of nanomoles per liter or less). The method is believed to be capable of such measurement capabilities at near real time sampling rates. The measurement of nitrite includes (a) treating an aliquot of the aqueous medium with a reagent that acidifies the aliquot, converts nitrite in the aliquot to nitrosium ion, and reacts with the nitrosium ion to yield a chemical species which fluoresces and (b) fluorometrically analyzing the resulting aliquot/reagent mixture to determine the concentration of such chemical species in the mixture, and thus to determine the concentration of nitrite in the aliquot and the aqueous medium from whence it came. The reagent is preferably an acidified solution in which the active ingredient is aniline. The measurement of nitrate is accomplished by treating a first aliquot of the aqueous medium in the manner described above to determine its nitrate concentration, treating a second aliquot (e.g. either sequentially with, or in parallel with the treatment of the first aliquot) to reduce the nitrate in the second aliquot to nitrite and measuring the resulting nitrite in the modified second aliquot in the manner described above, and using those two measurements to determine the concentration of nitrate in the second aliquot by difference. | 6 |
CROSS REFERENCE
[0001] This non-provisional utility application claims priority to U.S. Provisional Application Ser. No. 60/715,511, by inventor Jo{hacek over (z)}e Pe{hacek over (c)}e{hacek over (c)}nik, titled Remote Live Automatic Electro-Mechanical And Video Table Gaming, filed on Sep. 9, 2005, which is incorporated herein by reference.
FIELD OF INVENTION
[0002] The present invention relates to live table gaming, and is more particularly related to an automatic electro-mechanical and video table game that can remotely played by receipt of a live video feed of table game play with table game results.
BACKGROUND
[0003] With the increasing popularity of gaming, gaming competitors increasing enter the gaming marketplace. To remain competitive, each gaming company attempts to distinguish its goods and service from those of other gaming companies. Players, in response to the attention from gaming companies for their business, feel free to be more demanding of gaming companies. These demands include a plentiful supply of games of chance, both live and computer controlled.
[0004] Some players prefer computer controlled games such as video slot machines and video poker. As stated in Practical Casino Math , Second Edition (2005), by Hannum and Cabot, at page 64, “[t]oday's computer controlled gaming devices depend upon random number generators (RNG's) to select a ‘random’ symbol combination and ensure the game's fairness.” Some players prefer live table games such as roulette and dice games, perhaps because of distrust for the concepts or workings of RNG's, or because live games are better understood by these players. Another preference for live table games of chance may be due to a player's reliance on tangible sights and sounds that the player uses to form instincts and impressions upon which wagers are considered and placed.
[0005] Despite a preference for live table games of chance, several disadvantages are common among players having this preference. A casino will often set a minimum wager amount that can be bet at a live table game. A player who has little resources to make wagers will often be precluded from spending a desirable amount of time playing the live table game. As such, the casino will be unable to realize revenue from those players who would be playing the live table game but for the requirement of a relatively high minimum wager. A casino that cannot or will not accommodate smaller wagers from players will also lose the good will and loyalty of these players because their gaming desires will go unmet.
[0006] Some players, whether making large or small wagers, would prefer to play live table games while drawing little or no public attention. If possible, these players would play alone, though they prefer to play live table games over computer controlled table games. Few casinos, however, will provide a staffed table game for just one (1) player, unless that player consistently makes relatively high wagers (e.g., a ‘high roller’). Still further, some players would prefer to play table games alone, even without any casino employees attending to the table games. For these players, little choice is available for interactive table game play, other than wagering on games of chance in an anonymous user experience over online communications using the Internet or World Wide Web.
[0007] Still other players would prefer to play a leisurely, but live, table game. These players would like to take their time and would like to play without feeling any pressure or encouragement to hurry up and play faster. These players, who do not want to feel rushed when making wagers, are not able to do so at a live table game in a casino because those games must be hurried along by a casino employee who has a duty to accommodate the speed of play desired by other players at the table or by house rules.
[0008] In order to satisfy players wanting to play a live table game, a casino must pay wages and benefits to a casino employee who is charge of and supervises the live table game. Moreover, staffed casino security for the table game and its environment is also required to be paid for by the casino. This expense can considerably lower casino profit.
[0009] Given the foregoing, it would be desirable to avoid intervention by, and control of, a live table game by a casino worker. It would further be desirable to provide unattended live table game play where the table game is played without a live casino attendant. Accordingly, a need exists for an interactive, real time, networked, unattended, and live table game. A need also exists for such a live table game that can be activated to begin play by a remote client.
[0010] A need also exists for such a live table game that can be played without a minimum wager amount, that can be played with no time limit placed upon a player to place a wager, that can be played any time of the day or night, or combinations of the foregoing game variations. By fulfilling these needs, in their various combinations, gaming companies can accommodate players desiring the same and can thereby realize income from these live table gaming arrangements.
SUMMARY
[0011] Implementations provide for an electro-mechanical and video automatic table game device from which a broadcast is made of a live video feed of play of the table game. The broadcast, which also includes table game results, is made over a network. One or more remote clients can receive the broadcast on the network. Alternative implementations provide a back channel from the remote client to the electro-mechanical and video automatic table game device to remotely initiate play of the table game.
[0012] Implementations provide for a network facilitated over satellite, cable television, the Internet, the World Wide Web, a Wide Area Network (WAN), a Local Area Network (LAW), a wireless network, a hard wired network, or combinations thereof. Live table games include roulette, dice games, the big six wheel (wheel of fortune), and board games of chance.
[0013] The electro-mechanical and video automatic table game machine plays a game of chance that produces an analog result. The analog result is converted to a digital result for communication, along with a video feed of play at the table game, to a remote client operated by a player. As a function of the player's wager at the remote client and the digital result that is communicated to the remote client, the player's winnings or losses are calculated by the remote client. As such, the remote client need not send any electronic communication to the electro-mechanical and video automatic table game machine, other than to optionally initially activate the electro-mechanical and video automatic table game machine. Rather, the remote client only needs to receive a video feed and electronic result of table game play from the electro-mechanical and video automatic table game machine via a network (e.g., satellite, Cable TV, etc.).
[0014] Alternative implementations provide for an electro-mechanical and video automatic table game device that is not remotely activated by a remote client, but is rather continuously operated while a video feed of the game play is broadcast over a channel on a network to one more remote clients. The result of game play is also broadcast over the channel to each remote client that receives the live video feed. Wagers placed at the remote client are processed with the received digital result of game play to derive there from the player's winnings and losses. This monetary derivation can take place wholly at the remote client. The remote client, for instance, can be tuned to a channel of the network to receive the communication, where the network can be a satellite entertainment system or cable television.
[0015] Multiple selections can be made of live, or computer generated, games of chance, at least one of which includes an unattended live table game that can optionally be activated by the player via a back channel or other network communication from the remote client for interactive play by the player at the remote client.
[0016] A plurality of the electro-mechanical and video automatic table game machines can be placed in one or more unattended locations (e.g., a farm of electro-mechanical and video automatic table game machines in an unoccupied building). Broadcasts are made from each location. A broadcast of respective video feeds of table games from respective electro-mechanical and video automatic table game machines are made to a plurality of remote clients. In some implementations, an option is provided such that each of the remote clients can also send a communication to remotely start up game play at one or more such electro-mechanical and video automatic table game machine. Each electro-mechanical and video automatic table game machine can be so operated by only one remote client, by a plurality of remote clients, or by both.
[0017] A plurality of remote clients can interactively play a single electro-mechanical and video roulette or dice gaming machine. To coordinate such live table game play, a user interface on each remote client can have a time clock showing the time that remains to place a wager. At the expiration of the time, the electronic submission of wagers is terminated, further electronic wagers cannot be submitted, and the live action at the table game begins (e.g., a ball is set to rolling around a periphery of the roulette wheel of the electro-mechanical and video automatic roulette gaming machine, or dice are rolled in an electro-mechanical and video automatic die or dice gaming machine). Here, the remaining time to make a wager, and the cut off time for such wages, can be received by broadcast in a transmission over a network to each remote client that is tuned to a corresponding channel on the network.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] A more complete understanding of the implementations may be had by reference to the following detailed description when taken in conjunction with the accompanying documentation, wherein:
[0019] FIG. 1 shows, in an exemplary implementation, a plurality of streaming electronic gaming (e-gaming) environments in which a plurality of clients are in real time multimedia communication over one or more networks with a plurality of electro-mechanical and video automatic table game machines, and with a plurality of computer controlled gaming devices, wherein each client has an option for the user experience of remotely activating and interactively playing: (i) at least one electro-mechanical and video automatic table game machine in live action real time; and (ii) optionally also one or more computer controlled gaming device. Alternatively, electro-mechanical and video automatic table game machines can run their respective table games continuously while continuously broadcasting respective video feeds of table game play and game results there from over a network to a plurality of remote clients that are tuned to respective channels over which these data are broadcast;
[0020] FIG. 2 shows, in an exemplary implementation, a set top box/Digital Video Recorder (DVR) which can be used as a remote client in one or more of the environments of FIG. 1 ;
[0021] FIG. 3 shows, in an exemplary implementation, a satellite/CATV network for streaming real time live e-gaming content to a remote client by broadcast over a network from (i) at least one electro-mechanical and video table game machine in live action real time; and (ii) optionally also one or more computer controlled gaming device;
[0022] FIG. 4 shows, in an exemplary implementation, functionality for a remote client used in one or more of the environments of FIG. 1 , including for receiving streamed multimedia for a real time, interactive, live e-gaming user experience;
[0023] FIG. 5 shows, in an exemplary implementation, respective video cameras capturing live play alternately at a roulette wheel and at a dice game, where table game results and video feeds are broadcast, optionally upon demand of a remote client networked with the table games, to the remote client for display simultaneously with a user interface corresponding to the live video feed, where the live video feed and user interface provide an interactive user gaming experience at the remote client such as in the environments of FIG. 1 ; and
[0024] FIG. 6 shows, for each of several exemplary implementations, one or more remote clients in one geographic location as can be situated within the environments of FIG. 1 , wherein each remote client provides a user interface corresponding to the live table game being played using an electro-mechanical and video automatic table game device.
DESCRIPTION
[0025] An electronic gaming (e-gaming) service allows to a user to operate a client. The client is remote from an electro-mechanical and video automatic table game machine. The electro-mechanical and video automatic table game machine is unattended while operating a live table game. In one implementation, the client sends a communication that remotely activates (starts up) play of the live table game of chance at the electro-mechanical and video automatic table game machine. The e-gaming service controls interactive play of the live table game at the remote client. The electro-mechanical and video automatic table game machine, the e-gaming service, and the client are in multimedia communication over one or more networks. One or more remote clients can interactively operate, both individually and cooperatively, each of one or more of the electro-mechanical and video automatic table game machines over one or more networks.
[0026] In other implementations, a remote client can be tuned to a channel that sends a broadcast over a network. The broadcast includes a live video feed from an electro-mechanical and video automatic table game machine that plays a game without an attendant and that broadcasts game results on the channel over the network along with the live video feed. The remote client receives wagers which are used with the game results to calculate winnings and loses at the remote client. One or more remote clients can tune into a network channel to receive a broadcast of both a video feed and game results from one electro-mechanical and video automatic table game machine.
[0027] One or more remote clients can be located in a retail establishment, a casino, a place of gaming, etc. For instance, remote clients can be located at a private commercial establishment at which a restricted number of gaming machines are permitted by law. One or more electro-mechanical and video automatic table game machines for unattended operation of a live table game can be located in a warehouse, a retail establishment, a casino, a place of gaming, etc. For instance, a farm of electro-mechanical and video automatic table game machine can be located in an unoccupied building, where the building is attended only by occasional maintenance workers to maintain the building and to provide routine maintenance for the electro-mechanical and video automatic table game machines. Each electro-mechanical and video automatic table game machine has a video camera focused upon the live table game, which optionally can be remotely activated and interactively played by one or more remote clients. A video feed, and optionally an audio feed, from the live table game is communicated by broadcast on a channel over a network to each remote client tuned to the same for interactive game play at the respect remote client.
[0028] One or more networks provide multimedia broadcasts (i.e., video, data, and optionally audio) from the electro-mechanical and video automatic table game machines to the remote clients. These networks include, but are not limited to satellite, cable television, the Internet, the World Wide Web, a Wide Area Network (WAN), a Local Area Network (LAW), a wireless network, a hard wired network, and combinations thereof. By way of example, and not by way of limitation, each remote client and electro-mechanical and video automatic table game machine can be networked by techniques described in US Patent Publication No. 2004/0087357 by Johnson (teaches networking computer controlled table game devices), U.S. Pat. No. 5,762,552 issued to Vuong et al., U.S. Pat. No. 6,575,834 issued to Lindo, U.S. Pat. No. 5,830,069 issued to Soltesz et al, or U.S. Pat. No. 6,846,238 issued to Wells (teaches a wireless client in communication with a computer controlled gaming device, where the client can interactively make wagers and play the computer controlled gaming device).
[0029] In one implementation, a player can begin play by operating a remote client to select a live table game that is available to be played via a network at an electro-mechanical and video automatic table game machine. Such a selection can be made, in one implementation, via user interface that tunes the remote client to a channel of a network over which game play is being broadcast.
[0030] Optionally, the player can choose to be the only player that plays at the electro-mechanical and video automatic table game machine, such as where the player wants to take all the time the player desires between each wager without being rushed by another player or by house rules. Such a choice can be made via a transmission from the remote client to the selected electro-mechanical and video automatic table game machine, such as via a separate network or via a back channel of the broadcast network. Alternatively, the player can virtually join other players that are playing a live table game being operated unattended by an electro-mechanical and video automatic table game machine.
[0031] Each player can begin making wagers at a remote client by providing funding to the client. Means for funding the remote client can be as is conventional for video slots, video poker and other such computer controlled gaming devices. Means for funding a remote client that are yet to be developed are also contemplated for use with the present invention.
[0032] A player that loses a wager will have that wager deducted from funding previously provided to the remote client. The monetary winnings or loses are derived at the remote client by using the result of table game play that is broadcast on a channel over the network with the video feed of the game play at the table game. The video feed and the result of game play, for each unattended electro-mechanical and video automatic table game machine, can be broadcast on the same channel or on different channels.
[0033] A player that wins one or more wagers can receive payment for the one or more wagers at the location of the remote client at which the player made the wager. By way of example, and not by way of limitation, a player can play a client, remote from an electro-mechanical and video automatic table game machine, and located at a casino, gaming company, retail establishment, etc. The remote client, or a printer at the retail establishment, can cause a print out to be made of a receipt or ticket showing that the player has won one or more wagers, the client at which the one or more wagers was won, the game(s) that were played by the player, the date and time of the one or more wagers, one or more globally unique identification (GUID) or transaction numbers, and the amount of the players winnings from the one or more wagers. The player of the remote client can present the printed receipt to an attendant at the retail establishment. The attendant will then pay the player according to the printed receipt. Of course, other forms of payment to the player that wins one more wagers with the remote client are also contemplated, including both conventional ways presently known as well as ways yet to be developed that could be used with the present invention.
[0034] Each remote client can be a portal for accepting payment to interactively activate and play an unattended live table game of chance at an electro-mechanical and video automatic table game machine. The remote client can accept funds for wagers from a player, and can digitally receive the analog result of the table game of chance. The digitally received result that was converted from analog can be digitally communicated to the remote client, along with the video feed and over the same network (e.g., satellite, Cable TV, etc.)
[0035] In some implementations, calculations of a player's winnings or losses can be made at the electro-mechanical and video automatic table game machine, at a server, at the remote client, or at a combinations of these. The calculation is a function of the player's wager that was accepted at the remote client and the digital result that is communicated to the remote client. The player's funds can be deducted or awarded by the remote client based on the digitally received analog result of the remote live table game play. Thus, in some implementations, the remote client can provide an interactive live gaming experience to a player without sending electronic communications to the electro-mechanical and video automatic table game machine. Rather, the remote client can tune to and receive a broadcast that is limited to a video feed and a digital result of the game being played at the electro-mechanical and video automatic table game machine. The digitized result can there after be further processed with respect to a wager that had been made at a remote client, as well as for display at a user interface of the remote client.
[0036] The analog result from the game of chance at the live table game is derived electronically by the electro-mechanical and video automatic table game machine. If the game of change at the electro-mechanical and video automatic table game machine is a roulette game, then an electronic device can be embedded in the roulette wheel to detect and transmit where the ball stops rolling within the roulette wheel. If the game of chance at the electro-mechanical and video automatic table game machine is a dice game, then an electronic device can be embedded in each die to detect and then transmit the result of a roll of the die.
[0037] By way of example, and not by way of limitation, electro-mechanical and video automatic table game machines can be provided by the Elektron{hacek over (c)}ek Group (Interblock), which is an international game development and manufacturing company. The Interblock machines can be provided with means for finding an analog result from the game of chance at the live table game such that the analog result is digitized for communication to a user interface. Interblock can provide these gaming machines through one or more of the following entities:
I. The Elektron{hacek over (c)}ek Group (Elektron{hacek over (c)}ek d.o.o.), EGorenjska cesta 23, 1234 Menge{hacek over (s)}, Slovenia, phone: +386 1 724 77 10, fax: +386 1 724 77 65, e-mail: info@elektroncek-group.com; and II. Inter Casino Products (ICP), where member companies of the ICP Family are also members of the Elektron{hacek over (c)}ek Group:
A. ICP USA L.C., 6380 S. Valley View Blvd, Suite 104-106, NV 89118, Las Vegas, USA, 1-702-228-0060; and B. Inter Casino Products California LLC, ICP California LLC, 9912 Business Park Drive, Suite 185, CA 95827, Sacramento, USA, 1-916-363-7746.
[0042] Interblock, which has developed electromechanical gaming devices, includes (I) electro-mechanical and video roulette table gaming machines and (II) electro-mechanical and video dice gaming machine, both of which are described in Section I and II, below.
[0043] Section I: Electro-Mechanical and Video Roulette Table Gaming Machine
[0044] The electro-mechanical and video roulette table gaming machine has three (3) variations, each featuring a roulette theme. These three games are the Megastar, Supernova, and Queen. All three of these devices are multi-station devices allowing from as few as 4 to as many as 16 players individual play against the device at a single time. These devices have differences in the shape of the device, the number of players who may participate, and the placement of the wheel on the device.
[0045] The device is an electromechanical gaming device with a roulette theme. It is a multi-station device with a roulette style wheel housed under a glass dome. The wheel has alternating red and black numbered spaces around its edges and each numbered space is designed to accommodate a small white ball should it come to rest in any one of the spaces. The wheel continuously rotates and the speed of the wheel is randomly changed by one of three random number generators contained within the device. The other two random number generators dictate the velocity and spin of a roulette style ball which is mechanically propelled onto the spinning wheel during the play of the game. The device may be played by a single player or it can be played by multiple players who initiate play by inserting bill(s), ticket(s) with a monetary value encoded on it, or by deducting credits already accumulated and displayed at a video player station. Players play individually against the device.
[0046] Betting patterns and odds are displayed on a player's video station and may also be displayed on the devices' table-top depending on the model of the device. Upon the initiation of play, there is a pre-determined amount of time within which a player can place a bet or bets either by using a keyboard or by touching a video display screen located in front of each individual player. Once this pre-determined time has expired, the device will accept no more bets. Either prior to, or while players are placing bets within the pre-determined time period, a small white ball is propelled from a tube located under the glass dome onto the rotating wheel. Players may not place any more bets once the white ball slows to a pre-determined velocity (although the speed and spin of the ball is randomly determined, the device has the ability to monitor the velocity of the ball so that when it slows to a certain point betting may no longer occur.) Once the ball slows to a point where it comes to rest in one of the numbered slots on the wheel the device determines the winner(s), if any, and, based upon odds and amount wagered, credits the appropriate amount to the player(s)' account(s) (credits won may either be used for additional play or may be redeemed for cash.) At this time, the ball disappears into a tube beneath the wheel and players may again begin the process of placing wagers. Each player plays individually against the device and the outcome of a game is determined solely by chance. A complete game takes approximately 60 seconds; however, game speed may be controlled in one-second intervals so that a game may play between 60 and 90 seconds.
[0047] Before a player may operate Interblock's device, the player must first place a wager by inserting bill(s), ticket(s) with a monetary value encoded on it, or deducting credits already accumulated from previous games and displayed at a video player station. It is this insertion of money, ticket or redemption of accumulated credits which causes Interblock's device to operate.
[0048] Once a bet has been placed, a small white ball is propelled out of a tube onto the spinning roulette-style wheel housed under a dome on the device. Both the speed of the wheel and the velocity and spin of the wheel are determined randomly and are out of the player's control. The outcome of the game is known once the ball slows to the point where it comes to rest in one of the colored and numbered slots on the wheel. There is no player manipulation of where or when the ball stops. The game is controlled entirely by its three random number generators.
[0049] Players who play against Interblock's device do so for the opportunity to win money or credits that may be used for future play or redeemed for cash. Once the ball slows to a point where it comes to rest in one of the numbered slots on the wheel, the device determines the winner(s), if any, and, based upon odds and amount wagered, credits the appropriate amount to the player(s)' account(s).
[0050] Interblock's device is designed with video display graphics allowing a player to observe a virtual roulette betting layout including the odds for a bet. The video display also permits a player to review, among other things, the rules of play, results of a game, amount wagered, amount won or lost, and remaining credits, if any. Interblock's device provides a method for viewing the outcome and other information regarding the playing of games thereon or therewith.
[0051] Section II: Electro-Mechanical and Video Dice Gaming Machine
[0052] The electro-mechanical and video dice gaming machine features a theme of the Asian game known as Sic Bo. Sic Bo is a multi-station device allowing 5, 6 or 8 players to engage in individual play against the device at a single time in each game played. This is a multi-station device with three cubes on a circular 50 centimeter surface housed under a glass dome. Each cube has numbers on each side ranging from one to six. One cube is black and the other two cubes are white. The cubes are shaken by an automated platform in the center of the device. The platform is operated by random number generators contained within the device. The device may be played by a single player or it can be played by multiple players who initiate play by inserting bill(s), ticket(s) with a monetary value encoded on it, or by deducting credits already accumulated and displayed at a video player station. Players play individually against the device. Betting patterns and odds are displayed on a player's video station and may also be displayed on the device table top depending on the model of the device. To begin play, the player places a wager from the player station on one or more of the possible results. After all bets are made, the game is initiated by the device computer that puts the plate on which the three cubes are resting into a vibrating motion. The vibrating plate, or table, causes the cubes to shake and roll around the table for thirty seconds. When the table ceases vibrating and the cubes come to rest, there is an array of electronic sensors that read the cubes to determine cube location and value. The sensors can read the cubes since each side of each cube has a contactless card that represents the number on that side. This data is sent to the device computer and presented to the player on the player station LCD screen. The pays for the winning results range from 1 to 180 times the amount wagered.
[0053] Before a player may operate Interblock's device, the player must first place a wager by inserting bill(s), ticket(s) with a monetary value encoded on it, or deducting credits already accumulated from previous games and displayed at a video player station. It is this insertion of money, ticket or redemption of accumulated credits that causes Interblock's device to operate.
[0054] Once a bet has been placed, the platform in the center of the table commences to vibrate which causes the cubes to roll about the platform. The movement and speed of the platform are determined randomly and are out of the player's control. The outcome of the game is known once platform ceases its movement and the three cubes come to rest with one of each cube's six sides face up. There is no player or operator manipulation of where or when the cubes stop. The game is controlled entirely by its random number generators. The operation of Interblock's device is controlled by its computer program and is unpredictable and governed by chance.
[0055] Players who play against Interblock's device do so for the opportunity to win money or credits that may be used for future play or redeemed for cash. Once the cubes come to rest on the platform, the device determines the winner(s), if any, and, based upon odds and amount wagered, credits the appropriate amount to the player(s)' account(s).
[0056] Interblock's device is designed with video display graphics allowing a player to observe the odds for a bet. The video display also permits a player to review, among other things, the rules of play, results of a game, amount wagered, amount won or lost, and remaining credits, if any. Interblock's device provides a method for viewing the outcome and other information regarding the playing of games thereon or therewith.
[0057] Whether the electro-mechanical and video gaming features a dice or roulette table game, each can be modified, in a further implementation, to make a video image of live action at the table game in real time. Rather the using electronic devices to detect the result of game play, the video images of the game play can be analyzed, in real time, to derive from the video images the result of the game of chance. The derived result can be broadcast, along with the video feed, on a channel to which a remote client is tuned. The remote client can then further process the result to derive winnings and loses with respect to one or more wagers placed at the remote client by the player, and a visual display of the received result can be rendered upon a user interface at the remote client. A display of winnings and loses can also be displayed.
[0058] In still further implementations, in contrast to the foregoing, a system can be implemented to permit data to flow bi-directionally over one or more networks between remote clients and an e-gaming service that operates one or more electro-mechanical and video automatic table game machines. In such implementations, calculations of winnings and loss can occur at the e-gaming service, at the remote client, or at both places. This flow of data can include data for a player's choice of a table game, placement of a bet, digital receipt of an analog result of a live table game, multimedia streaming of the live table game action including video and optionally audio of electro-mechanical placements and movements of the elements and objects of the table game of chance (dice, ball, wheel, etc.).
[0059] A remote client, in addition to facilitating game play, can also accommodate computer controlled games of chance to be played, if so chosen by the player. Here, funding, wagers, and winnings can be handled at the remote client as has been described above.
[0060] Other forms of multi-media entertainment can be offered by the e-gaming service at the remote client, including movies, television, advertisements, and Internet and World Wide Web access. The remote client can also accept payment for order in an e-commerce application, such as ordering food, beverages, goods, and services for delivery anywhere including by room service at a hospitality establishment. Here, the e-commerce application can deliver to the remote client various product descriptions, images, and pricing, can facilitate building an electronic shopping cart filled with items electronically ordered at the remote client. The e-commerce application at the remote client can also initiate and completing a checkout process for the player's electronic shopping cart. The player can add additional products and services to the electronic shopping cart, change quantities, and remove items using the e-commerce component of the e-gaming service.
[0061] Privacy, security, and accessibility are provided to each player at a remote client via the inventive e-gaming service, which can be interoperable with conventional and future operating systems, platforms, open and proprietary software systems, and World Wide Web browser application software (e.g., Internet Explorer, Firefox, America Online, personal computers and Apple Macintosh, etc.).
[0062] A variety of electro-mechanical and video automatic table game machines are contemplated, each of which can be altered to accommodate the functionality as described herein. Such alternations include, but are not limited to, removing all or none of the user interface functionality physically located at the electro-mechanical and video automatic table game machine, and adding the previously described broadcast, network, or both broadcast and network communications with one or more remote clients each having a user interface for playing a live table game performed unattended at one of more electro-mechanical and video automatic table game machines. Functionality at the electro-mechanical and video automatic table game machine can optionally include communications capability to receive a remote activation demand from a remote client to begin interactive unattended live table play (e.g., to start up the game). The remote client can receive, and an electro-mechanical and video automatic table game machine can send, a live video feed and an optional audio feed over a network to the remote client.
[0063] FIG. 1 shows, in an exemplary implementation, a plurality of streaming e-gaming environments. Each environment can have a plurality of clients that are in real time multimedia communication over one or more networks with a plurality of electro-mechanical and video automatic table game machines. A plurality of computer controlled gaming devices are also seen in FIG. 1 . Each client is remote (not at the same physical, geographic location) from an electro-mechanical and video automatic table game machine with which it is in communication through one or more networks.
[0064] Each client, through a user interface having an input device, has an option to provide the user experience of remotely activating upon demand and interactively playing one or more electro-mechanical and video table game machines in live action real time game play. Alternatively, each client can also have the option to play one or more computer controlled gaming devices, which can also be remote from the client. By way of example, and not by way of limitation, such multiple games can be offered for play at each remote client by various techniques, including but not limited to the techniques described in US Pat Pub No 2004/0087357 by Johnson.
[0065] The user interface, thickness or thinness, form factor, and general functionality of the remote client can be as illustrated in FIG. 1 . By way of example, and not by way of limitation, the form factor and functionality can include a set top box, a wired or wireless personal digital assistant (PDA), a cellular telephone compatible of receiving multimedia streams (e.g., including but not limited to G2 through G4 telecommunications functionality), a bar top video gaming machine (video poker, video slot machines, etc.), a wired or wireless personal computing device (PC, laptop, palmtop, desktop, etc.), a game console platform in wired or wireless communication with a display device, and the like.
[0066] Each remote client, as seen in FIG. 1 , receives, but need not send, communications from an e-gaming service over one or more networks, including but not limited to broadcasts upon channels via satellite, cable television, the Internet, the World Wide Web, a Wide Area Network (WAN), a Local Area Network (LAN), a wireless network, a hard wired network, and combinations. In some implementations, the communications to the remote client are ‘one-way’. This one-way communication that is received by each remote client includes at least a video feed from an electro-mechanical and video automatic table game device and an digital result from game play at the electro-mechanical and video automatic table game device. By way of example, the remote client be tuned to a satellite or cable TV channel over which both the video feed and the digital result from game play is broadcast for processing at the remote client.
[0067] Each electro-mechanical and video automatic table game device, and optionally one or more computer controlled gaming devices, can communicate with the remote clients through one or more content providers associated with one or more head end(s) of a satellite or cable television service provider. A messaging server can optionally be used to deliver messages via networked communications between remote clients and electro-mechanical and video automatic table game machines.
[0068] FIG. 2 shows, in an exemplary implementation, a set top box (STB) as a remote client for receiving a video feed and table game results by broadcast from a satellite or cable television service provider. The STB has one or more options for providing a user interface with input device(s), including but not limited to a keyboard, an input pointing device, and a remote controller apparatus, each of which can be in wired or wireless communication with the STB and optionally with the illustrated network. A further option is a bi-directional communication capability between STB and one or more an electro-mechanical and video automatic table game devices. One such bi-directional capability can be provided by a back channel in a broadcast network. As such, the remote client can be useful in one or more of the environments seen in FIG. 1 .
[0069] FIG. 3 shows, in an exemplary implementation, further detail of one or more remote clients in a satellite/CATV network for streaming real time live e-gaming content from an electro-mechanical and video automatic table game device for the interactive playing of a table game of chance, and optionally also for the interactively activating and playing of a computer controlled game of chance. Both the electro-mechanical and video automatic table game device and the computer controlled game of chance are in communication, wired or wirelessly, with a means for providing streaming of program content. A transcoder encodes a binary stream of the program content, which includes multi-media streaming content from the electro-mechanical and video automatic table game device. One or more head-ends make a transmission of the binary stream via the satellite/CATV network. Each remote client that receives the transmitted binary stream will decodes the content for display and interactive use in the e-gaming application being executed at the remote client.
[0070] FIG. 4 shows, in an exemplary implementation, functionality provided by components of a remote client. The remote client illustrated in FIG. 4 can be used in one or more of the environments of FIG. 1 , including for receiving streaming multimedia so as to provide a real time, live e-gaming, interactive user experience.
[0071] FIG. 5 shows, in an exemplary implementation, two (2) video cameras. Each camera captures live play at a table game. One camera captures live play of a roulette wheel and the other captures live play at a dice game. Both the roulette wheel and the dice game are unattended and function as an electro-mechanical and video automatic table game device. One of the video feeds is communicated or broadcast to a remote client, as shown, when requested by the client (e.g., by the client tuning to the broadcast). By way of illustration, and not by way of limitation, the video feed can be accomplished by techniques described in U.S. Pat. No. 6,575,834 issued to Lindo or U.S. Pat. No. 6,908,385 issued to Green (teaches making video and audio recordings of live table games for a casino video security system that is provided where a camera is focused upon live table games in a casino environment).
[0072] A request for a live video feed is made using an user interface at a remote client. The client can request a video feed from either table game, as shown in FIG. 5 . In some implementations, the player at the client can initiate game play and then and experience live interactive play at the table game as facilitated by the player-selected electro-mechanical and video automatic table game device. As such, the remote client is networked with an e-gaming service to provide bi-directional communications. With the player-selected live video feed, a display of the video feed is made at the client.
[0073] A user interface can include a touch sensitive screen, keyboard, or other input device that is provided for interactive play of a player. Various user interfaces can be provided for various remote clients. Each user interface is adapted, and provides functionality, for playing a live table game of chance, such as roulette, dice games, the big six wheel or wheel of fortune (not shown), and board games of chance. As such, the user interface at the remote client will preferably correspond to the type of table game of chance being captured in the demand live video feed. The player sees a display of the live video feed and uses the user interface to place wagers at the remote client. Results of game play corresponding to the live video feed are broadcast to the remote client, so as to provide an interactive user experience of playing a table game of chance, such as is illustrated in one or more of the environments seen in FIG. 1 .
[0074] FIG. 6 shows, for each of several exemplary implementations, a suggested form factor, respectively, for various remote clients. Each remote client seen in FIG. 6 is in one geographic location that can be within one or more of the environments seen in FIG. 1 . A user interface is provided at each remote client for use in an implementation with respect to FIG. 2 . One or more remote clients can be embedded into a bar top. Each such remote client, whether standalone or clustered together and embedded into a single bar top surface, can be played by a patron of the bar while the patron is being attended by a bar tender. The bar tender can also attend to paying winnings to the patron when a wager by the patron at the remote client results in winnings. As such, the bar top, the bar establishment, or each client can have a printer (not shown) to print out a hardcopy of a receipt or ticket (not shown) that memorializes and provides evidence of the winnings, as described elsewhere herein. Another printer, or other internal controls providing similar functionality, can be provided at the geographic location so as to provide a similar receipt or like indicia of winnings. These two receipts can then be compared for accuracy and precision, thereby mitigating opportunities for the counterfeiting of receipts and/or other incidents of transactional fraud. In one implementation, there are a plurality of remote clients that are embedded into a bar top in a tavern or other retail establishment, where the establishment is a geographic location at which the number of gaming machines is restricted by gaming regulations.
[0075] A plurality displays can be clustered together, as shown in FIG. 6 , each of which corresponds to a separate user interface for a separate player. The user interface is used to remotely play the e-gaming service as described herein, where the video feed from the electro-mechanical and video automatic table game machine is displayed upon a corresponding display in the cluster of displays.
[0076] In a still further implementation, remote clients can be clustered together. Such a clustering, as seen in FIG. 6 , would be as is convention with slot machines, video poker machines, video slot machines, etc. in an unrestricted location such as a casino or other geographic location at which the number of gaming machines is unrestricted by gaming regulations.
[0077] The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope. | Electro-mechanical and video table games of chance send video feeds of game play and digital representations of results of game play by network communications to remote clients that receive wagers placed upon the result of the game play and derives a winning or a loss from both the wager and the digital representation of the result of the game play. The table game can include a roulette wheel, a roulette style ball, a device for rotating the roulette wheel at randomly changing rotational speeds, and a device for mechanically propelling the roulette style ball onto the rotating wheel at randomly changing velocities and spins. Also included can be a platform for supporting a die having a plurality of surfaces each bearing indicia unique to that on the other surfaces, and a device for randomly changing the movement and speed of the platform relative to the die. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2002-199915, filed Jul. 9, 2002, the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a non-volatile semiconductor memory device and a method of manufacturing the same. More particularly, the present invention relates to a NAND-type flash memory, which includes a floating gate electrode and two or more gate oxide films having a different thickness in peripheral and cell sections.
[0004] 2. Description of the Related Art
[0005] Recently, the development of a NAND-type flash memory has been made. The NAND-type flash memory is formed by gate pre-forming (or gate oxide film pre-forming) process. According to the gate pre-forming process, trench isolation is employed, and several gate oxide films having different thickness are separately formed.
[0006] However, in the NAND-type flash memory, gate oxide films 101 a and 102 a on a silicon (Si) substrate 103 are different in their thickness between a cell/Vcc section 101 and a Vpp section 102 , as shown in FIG. 5A. For this reason, a step (a) is formed in the upper surface of SiN films (stopper SiN films) 101 c and 102 c on gate electrodes 101 b and 102 b . For example, the step (a) is a factor of causing the following disadvantage in shallow-trench isolation (STI) formation. As illustrated in FIG. 5B, a difference is made in the thickness of SiN films when the upper surface of a buried insulator 104 is removed by chemical mechanical polishing (CMP) using SiN films 101 c and 102 c as a stopper. More specifically, the SiN film 102 c of the Vpp section 102 is thinner than the SiN film 101 c of the cell/Vcc section 101 . The excess thickness reduction of the SiN film 102 c is a factor of reducing the a height (h) to the gate oxide film 102 a . As a result, the gate oxide film 102 a is easily damaged by etching (e.g., wet etching) after CMP. The gate oxide film 102 a being damaged is a factor in causing failure such as gate leakage.
[0007] In particular, the NAND-type flash memory has a high-voltage row decoder circuit 111 . As shown in FIG. 6, the row decoder circuit 111 is arranged in a peripheral region (corresponding to Vpp section 102 ) adjacent to a cell array region (Cell Array) 110 corresponding to the cell/Vcc section 101 . Normally, the row decoder circuit 111 is formed using a gate oxide film for Vpp system (Vpp oxide film 102 a ). In other words, a high-voltage transistor exists in the row decoder circuit 111 of the NAND-type flash memory.
[0008] Conversely, a Vcc oxide film 101 a is used, in general, in the cell array region 110 , a guard ring 112 arranged between the cell array region 110 and the row decoder circuit 111 and a dummy AA pattern 113 near the row decoder circuit 111 . For this reason, when a film to make a buried insulator 104 is subjected to CMP in STI formation, the SiN film 102 c of the row decoder circuit 111 is excessively reduced in thickness as compared with the SiN film 101 c . This is a factor in causing the foregoing failure.
[0009] In the conventional case, it is possible to readily realize the NAND-type flash memory having several gate oxide films of different thicknesses according to the gate pre-forming process. However, the stopper SiN film of the row decoder circuit is greatly reduced in thickness by CMP in the STI formation. As a result, the gate oxide film under the stopper SiN film is easily damaged; for this reason, there is a problem that failure such as gate leakage occurs.
BRIEF SUMMARY OF THE INVENTION
[0010] According to a first aspect of the present invention, there is provided a non-volatile semiconductor memory device comprising: a semiconductor substrate; a memory cell array formed on the semiconductor substrate, and including a first gate insulator having a first thickness; a high-voltage transistor circuit formed on the semiconductor substrate, and including a second gate insulator having a second thickness greater than the first thickness; and a peripheral circuit formed on the semiconductor substrate, and including the second gate insulator.
[0011] According to a second aspect of the present invention, there is provided a method of manufacturing a non-volatile semiconductor memory device, comprising: successively depositing a first gate insulator having a first thickness, a first gate electrode film and a first mask insulator on a semiconductor substrate; leaving the first gate insulator, the first gate electrode film and the first mask insulator in only array region; separately forming the following gate insulators in a peripheral region excepting the array region, that is, forming a second gate insulator having a second thickness greater than the first thickness in a first region of a peripheral region, and forming a third gate insulator having a thickness the same as the first thickness in a second region of the peripheral region; successively depositing a second gate electrode film and a second mask insulator thicker than the first mask insulator on each of the first mask insulator, the second gate insulator and the third gate insulator; removing the second mask insulator and the second gate electrode film on the first mask insulator; forming an isolation trench on a surface of the semiconductor substrate to correspond to each position between the array region and first and second regions of the peripheral region; depositing a buried insulator on the entire surface; and polishing an upper surface of the buried insulator so that the upper surface can be planarized.
[0012] According to a third aspect of the present invention, there is provided a method of manufacturing a non-volatile semiconductor memory device, comprising: successively depositing a first gate insulator having a first thickness, a first gate electrode film and a first mask insulator on a semiconductor substrate; leaving the first gate insulator, the first gate electrode film and the first mask insulator in only an array region and a first peripheral region; forming a second gate insulator having a second thickness greater than the first thickness in a second peripheral region excepting the array region and the first peripheral region; successively depositing a second gate electrode film thinner than the first gate electrode film and a second mask insulator on each of the first mask insulator and the second gate insulator; removing the second mask insulator and the second gate electrode film on the first mask insulator; forming an isolation trench on a surface of the semiconductor substrate to correspond to each position between the array region and first and second regions of the peripheral region; depositing a buried insulator on the entire surface; and polishing an upper surface of the buried insulator so that the upper surface can be planarized.
[0013] According to a fourth aspect of the present invention, there is provided a method of manufacturing a non-volatile semiconductor memory device, comprising: previously forming a recess in a first peripheral region on a semiconductor substrate; forming a first gate insulator having a first thickness in the recess; forming a second gate insulator having a second thickness less than the first thickness in an array region and a second peripheral region on the semiconductor substrate; successively depositing first and second gate electrode films and first and second mask insulators on each of the first and second gate insulators; forming an isolation trench on a surface of the semiconductor substrate to correspond to each position between the array region and the first and second regions of the peripheral region; depositing a buried insulator on the entire surface; and polishing an upper surface of the buried insulator so that the upper surface can be planarized.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0014] [0014]FIG. 1A is a plan view showing a NAND-type flash memory according to a first embodiment of the present invention, and FIG. 1B is a cross-sectional view taken along a line IB-IB of FIG. 1A;
[0015] [0015]FIG. 2A to FIG. 2D are process cross-sectional views to explain a method of manufacturing a NAND-type flash memory according to a second embodiment of the present invention;
[0016] [0016]FIG. 3A to FIG. 3D are process cross-sectional views to explain a method of manufacturing a NAND-type flash memory according to a third embodiment of the present invention;
[0017] [0017]FIG. 4A to FIG. 4C are process cross-sectional views to explain a method of manufacturing a NAND-type flash memory according to a fourth embodiment of the present invention;
[0018] [0018]FIG. 5A and FIG. 5B are cross-sectional views showing the process of manufacturing a NAND-type flash memory to explain the prior art and the problem; and
[0019] [0019]FIG. 6 is a plan view showing a conventional a NAND-type flash memory.
DETAILED DESCRIPTION OF THE INVENTION
[0020] Embodiments of the present invention will be described below with reference to the accompanying drawings.
[0021] (First Embodiment)
[0022] [0022]FIG. 1A and FIG. 1B show the structure of a NAND-type flash memory formed by gate pre-forming (or gate oxide pre-forming) process according to a first embodiment of the present invention. FIG. 1A is a plan view showing principal parts of the NAND-type flash memory, and FIG. 1B is an enlarged view showing the sectional structure substantially corresponding to line IB-IB of FIG. 1A.
[0023] In the NAND-type flash memory, a cell array 21 is formed in an array region on a Si substrate 11 . A high-voltage row decoder circuit (high-voltage transistor) 31 is formed in a peripheral region adjacent to the cell array 21 . A guard ring 41 functioning as a peripheral circuit is formed between the cell array 21 and the row decoder circuit 31 . The peripheral region is formed with a dummy AA pattern (peripheral circuit) near the row decoder circuit 31 .
[0024] In the cell array 21 , an N-well region (Cell N-well) 21 A is formed on the surface of the Si substrate 11 . In the N-well region 21 A, a P-well region (Cell P-well) 21 B is formed. A plurality of memory cells (not shown) are formed on the surface of the P-well region 21 B. Each memory cell has a structure in which a poly gate electrode (first gate electrode film) 21 b and a SiN film (first mask insulator) 21 c are stacked on a Vcc gate oxide film (Vcc oxide film) 21 a . The poly gate electrode includes such as poly silicon, polycide and the like. The gate oxide film 21 a is a first gate insulator having a first thickness. The SiN film 12 c functions as the stopper in CMP.
[0025] Conversely, the row decoder circuit 31 , guard ring 41 and dummy AA pattern 51 are formed using high breakdown voltage (Vpp) gate oxide films (Vpp oxide film) 31 a , 41 a and 51 a , respectively. Each of the gate oxide films 31 a , 41 a and 51 a is a second gate insulator having a second thickness greater than the first thickness of the gate oxide film 21 a . In other words, the row decoder circuit 31 includes a high-voltage transistor (not shown) formed on the surface of the Si substrate 11 . The high-voltage transistor has a structure in which a poly gate electrode (second gate electrode film) 31 b and a SiN film (second mask insulator) 31 c are stacked on the Vpp gate oxide film 31 a . The SiN film 31 c functions as the stopper in CMP. The guard ring 41 is formed on each surface of well regions 21 A, 21 B and N-well (NW) 41 A. Each guard ring 41 has a structure in which a poly gate electrode (second gate electrode film) 41 b and a SiN film (second mask insulator) 41 c are stacked on the Vpp gate oxide film 41 a . The SiN film 41 c functions as the stopper in CMP. The dummy AA pattern 51 is formed on the surface of the Si substrate 11 adjacent to the row decoder circuit 31 . The dummy AA pattern 51 has a structure in which a poly gate electrode (second gate electrode film) 51 b and a SiN film (second mask insulator film) 51 c are stacked on the Vpp gate oxide film 51 a . The SiN film 51 c functions as the stopper in CMP.
[0026] An STI isolation region 12 burying insulator is formed between regions ( 21 and 41 , 41 and 31 , 31 and 51 ).
[0027] Conventionally, the guard ring and dummy pattern in the periphery of the row decoder circuit have been formed using a Vcc oxide film. The guard ring and dummy pattern are formed in a high-breakdown-voltage oxide film region. Namely, the guard ring 41 and the dummy AA pattern 51 are formed using Vpp oxide films 41 a and 51 a , respectively. In this way, it is possible to offset the step (global step shown by “a” in FIG. 5A) on the upper surface of the stopper SiN film 31 c around the high-voltage transistor of the row decoder circuit 31 . As a result, the SiN film 31 is prevented from being excessively reduced in thickness, so that a sufficient height (h) to the Vpp oxide film 31 a can be secured.
[0028] The structure described above is employed, and thereby, the following effect is obtained. It is possible to prevent only residual film thickness of the SiN film 31 c from being greatly reduced between the guard ring 41 and the row decoder circuit 31 and between the row decoder circuit 31 and the dummy AA pattern 51 . Therefore, it is possible to solve the conventional problem of reducing a margin for CMP when gate pre-forming process is employed because the NAND-type flash memory has the high-voltage transistor in the row decoder section. As a result, the Vpp oxide film 31 a of the row decoder circuit 31 is prevented from being easily damaged, and failure such as gate leakage is prevented.
[0029] (Second Embodiment)
[0030] [0030]FIG. 2A to FIG. 2D show a method of manufacturing a NAND-type flash memory formed by gate pre-forming process according to a second embodiment of the present invention. Here, the cell section formed with the cell array has a different structure with the Vcc section formed with a guard ring and a dummy AA pattern.
[0031] As shown in FIG. 2A, the following films are formed in the array region (cell section) on the Si substrate 11 . The films are Vcc oxide film (first gate insulator 21 a having the first thickness, poly gate electrode (first gate electrode film) 21 b and stopper SiN film (first mask insulator) 21 c . In this case, various materials are deposited on the Si substrate 11 , and thereafter, patterning is carried out. The Vcc oxide film 21 a , poly gate electrode 21 b and stopper SiN film 21 c formed in peripheral regions (Vpp section/Vcc section) other than the array region are removed. In this way, the Si substrate 11 of the peripheral region is exposed.
[0032] As illustrated in FIG. 2B, one region (Vpp section) of the peripheral regions on the Si substrate is formed with the Vpp oxide film (second gate insulator) 31 a having a second thickness greater than the first thickness of the Vcc oxide film 21 a . The other region (Vcc section) of the peripheral regions is formed with Vcc oxide films (third gate insulator) 41 a ′ and 51 a ′ having a thickness the same as the first thickness of the Vcc oxide film 21 a . Thereafter, a poly gate electrode material 61 b and stopper SiN film material 61 c are successively deposited on the stopper SiN film 21 c , Vpp oxide film 31 a and Vcc oxide films 41 a ′ and 51 a ′. In this case, the thickness of the stopper SiN film material 61 c is made greater than that of the stopper SiN film 21 c.
[0033] As depicted in FIG. 2C, the poly gate electrode material 61 b and stopper SiN film material 61 c formed on the cell section is removed. In this way, the poly gate electrode (second gate electrode film) 31 b and the stopper SiN film (second mask insulator) 31 c are stacked on the Vpp oxide film 31 a of the Vpp section. The poly gate electrodes (second gate electrode film) 41 b , 51 b and the stopper SiN film (second mask insulator) 41 c , 51 c are stacked on the Vcc oxide film 41 a ′ and 51 a ′ of the Vcc section, respectively.
[0034] As seen from FIG. 2D, an isolation trench 71 is correspondingly formed on the surface of the Si substrate 11 between the cell section and peripheral regions, that is, Vpp section/Vcc section (STI formation). A buried insulator 72 is deposited, and thereafter, planarizing by CMP is carried out, and thus, a STI-structure isolation 12 is formed.
[0035] Thereafter, memory cell, row decoder circuit (high-voltage transistor), and guard ring and dummy AA pattern are formed with respect to cell section, Vpp section, and Vcc section, respectively (although these formations are not shown). In this manner, a NAND-type flash memory is realized.
[0036] In the embodiment, the SiN film material 61 c ( 31 c , 41 c , 51 c ) of the peripheral regions (i.e., Vcc and Vpp sections) is formed to be thicker than the SiN film material 21 c of the cell section. In this way, it is possible to prevent the thickness of the SiN film 31 c from being reduced by CMP. In addition, it is possible to make large enough the height h1 to the Vpp oxide film 31 a and the height h2 to Vcc oxide film 41 a ′, 51 a ′. Therefore, this serves to prevent gate oxide film (Vpp oxide film 31 a ) from being damaged in the process after CMP; as a result, a sufficient margin for CMP can be achieved.
[0037] As described above, the SiN film used as the stopper in CMP for STI formation is formed separately in its thickness in the cell section and the peripheral regions. More specifically, the SiN film of the Vpp section is formed to be thicker than that of the cell section. In this way, it is possible to increase the residual film thickness of the SiN film of the high-voltage transistor in process. As a result, a sufficient margin for CMP can be achieved.
[0038] In addition, the second embodiment has the following advantage, unlike the first embodiment. Namely, Vcc oxide films 41 a ′ and 51 a ′ of the guard ring 41 and the dummy AA pattern 51 formed in the Vcc section need not be formed to have the same thickness as the Vpp oxide film 31 a.
[0039] (Third Embodiment)
[0040] [0040]FIG. 3A to FIG. 3D show a method of manufacturing a NAND-type flash memory formed by gate pre-forming process according to a third embodiment of the present invention. Here, the cell section formed with the cell array and the Vcc section formed with the guard ring and the dummy AA pattern have the same structure.
[0041] As shown in FIG. 3A, the following films are formed in the array region (cell section) and Vcc section (first peripheral region) on the Si substrate 11 . The films are Vcc oxide films (first gate insulator) 21 a , 41 a ′ and 51 a ′ having the first thickness, poly gate electrodes (first gate electrode film) 21 b , 41 b and 51 b and stopper SiN films (first mask insulator) 21 c , 41 c and 51 c . In this case, various materials are deposited on the Si substrate 11 , and thereafter, patterning is carried out. The Vcc oxide films 21 a , 41 a ′ 51 a ′, poly gate electrodes 21 b , 41 b , 51 b and stopper SiN films 21 c , 41 c , 51 c formed in a Vpp section (second peripheral region) other than the array region and the Vcc section are removed. In this way, the Si substrate 11 of the Vpp section is exposed.
[0042] As illustrated in FIG. 3B, the Vpp section on the Si substrate is formed with the Vpp oxide film (second gate insulator) 31 a having the second thickness thicker than the Vcc oxide film 21 a . Thereafter, a poly gate electrode material 61 b and stopper SiN film material 61 c are successively deposited on the stopper SiN films 21 c , 41 c , 51 c and the Vpp oxide film 31 a . In this case, the thickness of the poly gate electrode material 61 b is made thinner than the poly gate electrodes 21 b , 41 b and 51 b . In addition, the stopper SiN film material 61 c is deposited to be flush with the upper surface of the stopper SiN films 21 c , 41 c and 51 c.
[0043] As depicted in FIG. 3C, the poly gate electrode material 61 b and stopper SiN film material 61 c formed on the cell and Vcc sections are removed. In this way, the poly gate electrode (second gate electrode film) 31 b and the stopper SiN film (second mask insulator) 31 c are stacked on the Vpp oxide film 31 a of the Vpp section.
[0044] As seen from FIG. 3D, an isolation trench 71 is correspondingly formed on the surface of the Si substrate 11 between the cell section and the Vpp/Vcc section (STI formation). A buried insulator 72 is deposited, and thereafter, planarizing by CMP is carried out, and thus, a STI isolation 12 is formed.
[0045] Thereafter, memory cell, row decoder circuit (high-voltage transistor) and guard ring and dummy AA pattern are formed with respect to cell section, Vpp section and Vcc section, respectively (these formations are not shown). In this way, a NAND-type flash memory is realized.
[0046] In the embodiment, stopper SiN films 31 c and 21 c of the row decoder circuit and the cell section are readily formed in a state their upper surfaces are flush with each other. In this way, it is possible to prevent an extra reduction of the thickness of the SiN film 31 c in CMP, and to sufficiently take the height to the Vpp oxide film 31 a . Therefore, this serves to prevent the gate oxide film (Vpp oxide film 31 a ) from being damaged in the process after CMP; as a result, a sufficient margin for CMP can be achieved.
[0047] As described above, the SiN film used as the stopper in CMP for STI formation is formed separately in its thickness in the cell section and the Vpp section. More specifically, stopper SiN films of the Vpp section and the cell section are readily formed in the state that their upper surfaces are flush with each other. In this way, it is possible to increase the residual film thickness of the SiN film of the high-voltage transistor in process. As a result, a sufficient margin for CMP can be achieved.
[0048] In addition, according to the third embodiment, only Vpp oxide film 31 a can be formed to be thicker than Vcc oxide films 41 a ′ and 51 a ′, like the second embodiment described before.
[0049] (Fourth Embodiment)
[0050] [0050]FIG. 4A to FIG. 4C show a method of manufacturing a NAND-type flash memory formed by gate pre-forming process according to a fourth embodiment of the present invention. Here, the cell section formed with the cell array and the Vcc section formed with guard ring and dummy AA pattern have the same structure.
[0051] As shown in FIG. 4A, the surface of the Si substrate 11 is selectively etched using a photo engraving process (PEP) and dry etching techniques. In this way, the Vpp section (first peripheral region) is formed with a recess 81 , which has a height lower than the cell and Vcc sections. In this case, the depth of the recess 81 is approximately the same as the thickness of the Vpp oxide film (first gate insulator) formed therein.
[0052] As illustrated in FIG. 4B, a Vpp oxide film 31 a having a first thickness is formed in the recess 81 formed at the Vpp section on the Si substrate 11 . Vcc oxide films (second gate insulator) 21 a , 41 a ′ and 51 a ′ having a second thickness less than that of the Vpp oxide film 31 a are formed in the array region (cell section) and the Vcc section (second peripheral region) on the Si substrate 11 . Thereafter, a poly gate electrode material 61 b and stopper SiN film material 61 c are successively deposited on the Vcc oxide films 21 a , 41 a , 51 a and the Vpp oxide film 31 a . In this way, poly gate electrodes (second gate electrode film) 21 b , 41 b , 51 b and stopper SiN films (second mask insulator) 21 c , 41 c , Sic are stacked on the Vcc oxide films 21 a , 41 a ′ and 51 a ′ of the cell and Vcc sections. The poly gate electrode (first gate electrode film) 31 b and the stopper SiN film (first mask insulator) 31 c are stacked on the Vpp oxide film 31 a of the Vpp section. In this case, the Vpp oxide film 31 a is formed in the recess 81 , and thereby, the surface of the stopper SiN film 31 c is approximately flush with that of the stopper SiN films 21 c , 41 c and 51 c.
[0053] As depicted in FIG. 4C, an isolation trench 71 is correspondingly formed on the surface of the Si substrate 11 between the cell/Vcc section and the Vpp section, that is, Vpp section/Vcc section (STI formation). A buried insulator 72 is deposited, and thereafter, planarizing by CMP is carried out, and thus, a STI isolation 12 is formed.
[0054] Thereafter, a memory cell, row decoder circuit (high-voltage circuit) and guard ring and dummy AA pattern are formed with respect to the cell section, Vpp section and Vcc section, respectively (these formations are not shown). In this way, a NAND-type flash memory is realized.
[0055] In the embodiment, the silicon surface of the Vpp section is positioned lower than the cell section by the film thickness of the Vpp oxide film 31 a . Thus, the upper surface of the SiN film 31 c is readily flush with that of the SiN film 21 c of the cell section. In this way, it is possible to prevent an excess reduction of thickness of the SiN film 31 c by CMP, and to achieve a sufficient height to the Vpp oxide film 31 a . Therefore, this serves to prevent gate oxide film (Vpp oxide film 31 a ) from receiving damage in process after CMP; as a result, a sufficient margin for CMP can be achieved.
[0056] As described above, the SiN film used as the stopper in CMP for STI formation is formed separately in its thickness in the cell section and peripheral regions. More specifically, the stopper SiN film of the Vpp section is formed to have the same thickness as that of the cell section. In this way, it is possible to increase the residual film thickness of the SiN film of the high-voltage transistor in process. As a result, the margin for CMP can be sufficiently obtained.
[0057] In addition, according to the fourth embodiment, only Vpp oxide film 31 a can be formed to be thicker than Vcc oxide films 41 a ′ and 51 a ′, like the second and third embodiment described before.
[0058] Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents. | A non-volatile semiconductor memory device includes a semiconductor substrate, a memory cell array formed on the semiconductor substrate, and including a first gate insulator having a first thickness. The device further includes a high-voltage transistor circuit formed on the semiconductor substrate, and including a second gate insulator having a second thickness greater than the first thickness, and a peripheral circuit formed on the semiconductor substrate, and including the second gate insulator. | 7 |
RELATED APPLICATIONS
This application is the U.S. National Phase under 35 U.S.C. §371 of International Application No. PCT/GB2007/000898, filed Mar. 14, 2007, designating the U.S. and published in English on Sep. 20, 2007 as WO 2007/104985, which claims priority under 35 U.S.C. §119(a)-(d) to United Kingdom Patent Application No. GB0605376, filed Mar. 16, 2006. The content of these applications is incorporated herein by reference in their entireties.
The present invention relates to preparations and compositions for the treatment or relief of disease; for example, diseases where excessive mucous is a problem, diseases where abnormal quantities of mucous are (or may be) problematic, and/or inflammatory disease (such as inflammatory respiratory diseases, for example asthma and/or allergic airways disease).
Chronic obstructive pulmonary disease (COPD) is characterised by a range of pathological changes of the respiratory system, including airflow limitation, inflammation, ciliary dysfunction, and increased mucous production. COPD also has significant systemic consequences. Although improving lung function and disease systems have been the main focus of COPD management, these parameters alone do not reflect the full burden of the disease. The term COPD encompasses a mixture of disease processes, the composition of which varies between individuals: these may include chronic bronchitis, small airway disease (for example, chronic bronchiolitis, laryngitis, pharyngitis), emphysema, and large airway disease (for example tracheitis). As COPD progresses, disruption of gas exchange can result in chronic hypoxia and cor pulmonale.
Cystic fibrosis (CF) causes the exocrine glands (which produce sweat and mucus) to produce abnormal secretions—unusually thick, sticky mucus that clogs the lungs and leads to chronic respiratory problems. The mucus also obstructs the ducts in the pancreas, preventing digestive enzymes from reaching the intestines and helping to properly digest food. As a result, people with cystic fibrosis have trouble breathing and absorbing nutrients and as well as eliminating non-digested food.
Other diseases or conditions that are associated with increased mucous production include inflammatory bowel disease such as irritable bowel syndrome, bowel parasite infections, mucoid enteritis, Crohn's colitis, vaginitis, ulcerative colitis, and post-operative gastrointestinal surgery symptoms or complications.
Asthma is recognized as a chronic inflammatory disorder of the airways in which many cells and cellular elements play a role (for example, mast cells, eosinophils, T lymphocytes, neutrophils, and epithelial cells). In susceptible individuals, this inflammation causes recurrent episodes of wheezing, breathlessness, chest tightness, and cough, particularly at night and/or in the early morning. These episodes are usually associated with widespread but variable airflow obstruction that is often reversible either spontaneously or with treatment. The inflammation also causes an associated increase in the existing bronchial hyper responsiveness to a variety of stimuli. The airway inflammation may be variably associated with changes in airway hyper responsiveness, airflow limitation, respiratory symptoms, and disease chronicity. The airway inflammation may be acutely and chronically associated with the development of airflow limitation as the result of bronchoconstriction, airway oedema, mucus secretion, and, in some patients, airway wall remodelling.
Aspergillosis is the name given to a wide variety of diseases caused by the genus of fungi Aspergillus . The most common forms are allergic bronchopulmonary aspergillosis, pulmonary aspergilloma and invasive aspergillosis. Compromised immune systems often allow Aspergillus to colonize.
There is a need for medicaments which may be used to treat or ameliorate (or prevent in at risk groups) disease by reduction of excessive mucous production (e.g. bringing mucous production back to normal levels), for example, excessive pulmonary mucous production. For example, there is a need for medicaments which treat or ameliorate the symptoms of COPD and CF, for example by reducing mucous production—e.g. by reducing excessive mucous production such as excessive pulmonary mucous production (and, for example, the consequent production of phlegm (sputum), which results in bouts of productive coughing). There is a need for medicaments to treat respiratory disease, for example inflammatory respiratory diseases such as asthma and/or allergic airways disease, and other inflammatory diseases such as Aspergillosis ( Aspergillus ). There is a need for medicaments to treat disease by treating abnormal (e.g. treating by reduction of) mucous production (for example pulmonary mucous production, abnormal mucous production in the gut, mucous production caused by allergic and/or immune reaction). There are an increasing number of people who are not able to use conventional pharmaceuticals (for example, due to allergies, side-effects or for ethical reasons). Thus, there is an increasing need for medicaments which are made of components from natural ingredients such as plant extracts, rather than conventional pharmaceutical compounds.
According to the present invention there is provided a composition comprising: ginkgo biloba , or extract (e.g. standardized extract) or component thereof; apocynin; and a gingerol. The composition may comprise ginkgo biloba or extract or component thereof; apocynin; and a gingerol; wherein at least 3.9% by weight of the composition is gingerol; and at least 0.05% by weight of the composition is apocynin.
The applicant has found that compositions according to the invention may have a remarkable effect in treating abnormal (e.g. reducing excessive) mucous production, especially excessive pulmonary mucous production. The applicant has found that compositions according to the invention may have a remarkable effect in treatment of inflammatory disease.
The applicant has surprisingly found that the use of a gingerol (or gingerols) in combination with ginkgo biloba (or extract or component thereof) and apocynin provides a substantial clinical improvement; and especially a substantial reduction in excessive mucous production. It is apparent that there is a beneficial, e.g. synergistic, clinical outcome when a gingerol (or gingerols) is added to a preparation comprising ginkgo biloba (or standardised extract or component thereof), and apocynin.
Herein, the term “gingerol” includes compounds such as 4-gingerol, 6-gingerol, 7-gingerol, 8-gingerol, 9-gingerol, 10-gingerol, 12-gingerol, 14-gingerol, 16-gingerol, dihydrogingerol(s), methyl-gingerol, and/or pharmaceutically acceptable salts thereof. The term “gingerol” includes these (and other) compounds, for example 6-gingerol, 8-gingerol, present as part of an unresolved mixture of compounds in the form of an unpurified plant or root extract. The term “gingerol” includes these (and other) compounds, for example 6-gingerol, 8-gingerol, which are present or used in a purified or synthetic form (e.g. a gingerol compound such as those mentioned above which has been synthesized, or which has been extracted from a plant, root etc. and purified). Further, the term gingerol also includes heat or transformation (or other) products such as mixtures of phenolic compounds with carbon side chains consisting of 7 or more carbon atoms, gingerdiones, gingerdiols, shogaols, paradols and zingerone, either in the form of plant extracts, or in purified or synthetic form. If a gingerol is present in compositions according to the invention as a direct extract from a plant (that is, as part of an unresolved mixture of compounds in the form of an unpurified plant or root extract), it may be referred to as a gingerol or gingerols “in the natural form” or “natural gingerol”. For example, gingerol present in compositions according to the invention in the form of Zingiber Officinale (and other members of the Zingiberaceae family such as Languas galangal or Alpinia galangal commonly known as Galangal), other gingerol(s) containing plants such as Aframomum melegueta , phytochemical constituents of, for example, the Zingiberaceae family, and/or standardised extract(s) thereof, may be referred to as “natural gingerol”. Alternatively or additionally, the gingerol may be used in the composition or preparation in a purified or synthetic form, and this may be referred to as “isolated gingerol”. For example, if gingerol is present in compositions according to the invention as purified 6-gingerol and/or 8-gingerol or synthetic 6-gingerol and/or 8-gingerol (or other gingerol phytochemical or phytochemicals) this may be referred to as isolated gingerol. The term gingerol includes mixtures of two or more gingerols, as set out above.
The gingerol (or gingerols) may be present in the natural form, for example as Zingiber officinale or an extract thereof. The gingerol (or gingerols) in the natural form may be an extract which is standardised based on a standard amount of gingerols; such nomenclature is well known in the art. Thus, gingerol in the natural form (natural gingerol(s)) may comprise Zingiber officinale standardised to a gingerol fraction of between 1% and 10%, for example Zingiber officinale standardised to contain 5% gingerol. The gingerol in the natural form (e.g. Zingiber officinale standardised to 5% gingerol) may include one or more of 6-gingerol, 8-gingerol, 10 gingerol, and shogaols). In the Examples below, the natural gingerol (when present) is in standardised form and comprises Zingiber officinale standardised to 5% gingerol.
The gingerol (or gingerols) may be present in the isolated form, for example as 6-gingerol and/or 8-gingerol (present or used in a purified or synthetic form).
The compositions according to the invention may include at least 3.9% by weight of the gingerol (or gingerols). For example at least 5% by weight of the total composition may be gingerol (or gingerols), for example at least 10% by weight of the total composition may be gingerol (or gingerols), for example at least 15%, 20%, 25% or 30% by weight of the total composition may be gingerol (or gingerols).
The compositions according to the invention include apocynin. Apocynin is the plant-phenol 4-hydroxy-3-methoxyacetophenone.
Apocynin interferes with the arachidonic acid cascade, increases glutathione synthesis, and is a neutrophil oxidative burst agonist. The compositions (and preparations) of the invention may include an “isolated apocynin”, which is apocynin which has been synthesized, or which has been extracted from plants and purified. The apocynin may be in isolated form (e.g. apocynin). The apocynin may be in the form of a precursor, for example the dimer, a Glucoside (for example androsin), a glycone, or in the form of acetovanillone). Apocynin may also (alternatively or additionally) be present in preparations or compositions according to the invention as direct extracts from apocynin containing plants such as Picrorrhiza kurroa, Apocynum cannabinum, Apocynum venatum , or Apocynum androsaemifolium , for example an extract from Picrorrhiza kurroa (for example as part of an unresolved mixture of compounds in the form of an unpurified plant or root extract); these extracts from apocynin-containing plants will be referred to as apocynin “in the natural form” or “natural apocynin”. For example, apocynin present in preparations according to the present invention in the form of Picrorrhiza kurroa (or extract thereof) may be referred to as “natural apocynin”. Natural apocynin or apocynin in the natural form may include androsin, glycosides of apocynin, and/or other iridoid glucosides, for example.
The apocynin may be used in the preparation as “isolated apocynin” and also as “natural apocynin”. The use of the active entity in the natural form in combination with the “isolated” active entity may lead to a further beneficial, e.g. synergistic, effect between the isolated form (e.g. purified or synthetic apocynin) and the natural form (the apocynin contained in, for example, Picrorrhiza kurroa ).
The natural apocynin may be Picrorrhiza kurroa in standardised form, such as is well known. The natural apocynin may be Picrorrhiza kurroa standardised to a total amount (by weight) of apocynin and/or androsin of between 1% and 60%, for example Picrorrhiza kurroa standardised to contain 5% apocynin and/or androsin, 10% apocynin and/or androsin, 15% apocynin and/or androsin, 20% apocynin and/or androsin, 25% apocynin and/or androsin, 30% apocynin and/or androsin, 50% apocynin and/or androsin. In the examples below, the Picrorrhiza kurroa is Picrorrhiza kurroa standardised to a total amount (by weight) of apocynin of 10%. It will be understood that other forms of natural apocynin may be used instead of or in addition to Picrorrhiza kurroa ; such other forms may also be standardised to a total amount (by weight) of apocynin and/or androsin of between 1% and 60%, e.g. 10%.
The natural apocynin may be Picrorrhiza kurroa in standardised form based on standardised iridoid glucoside fractions such as are well known. The Picrorrhiza kurroa in standardised form may comprise standardised iridoid glucoside fractions collectively known as “Kutkin min 4%”. Standardised iridoid glucoside fractions between Kutkin min 2% and Kutkin min 8% are also preferred. Kutkin is obtained by crystallisation and comprises the glucosides picroside I and kutoside in a ratio of 1:2 and other minor glycosides (Sing and Rastogi, 1972, Ansan et al., 1988).
At least 0.05% by weight of the composition may be apocynin. If the composition comprises apocynin in the form of Picrorrhiza kurroa , at least 0.5% by weight of the composition may be Picrorrhiza kurroa . The composition may include apocynin in an amount which is at least 1% by weight of the total composition. For example, at least 5% by weight of the composition may be apocynin, for example, at least 10%, 15%, 20%, 25% or 30% by weight of the composition may be apocynin.
The composition includes ginkgo biloba ; or extract or component thereof. The ginkgo biloba may be in concentrated standard form, such as is well known in the art. For example, the ginkgo biloba may be a concentrated extract which is equivalent to four times the concentration of ginkgo biloba in the natural form, such as ginkgo biloba tablets sold by MediHerb of Australia (500 mg tablets containing ginkgo biloba concentrated extract equivalent to 2.0 g dry leaf ginkgo biloba standardised to contain 22-26% Ginkgo flavone glycosides). The composition may include a component of ginkgo biloba , for example a Ginkgolide or bilobalide. The component of ginkgo biloba may be one or more of Ginkgolide A, Ginkgolide B, Ginkgolide C, Ginkgolide J or Ginkgolide M. The composition may include Ginkgo biloba; or extract or component therof in an amount which is at least 1% by weight of the total composition. For example, at least 5% by weight of the composition may be ginkgo biloba ; or extract or component therof, for example, at least 10%, 15%, 20%, 25% or 30% by weight of the composition may be ginkgo biloba ; or extract or component therof.
The composition may comprise ginkolide B, apocynin and gingerol-6. The composition may comprise ginkolide A, apocynin and gingerol-6. The composition may comprise ginkolide B, apocynin and gingerol-8. The composition may comprise ginkolide A, apocynin and gingerol-8.
The composition (or preparation) may further comprise an agent which enhances lipid solubility and/or lipid miscibility of the preparation. This may give rise to better absorption—e.g. intestinal absorption—and hence better bioavailability, especially by the oral route. The agent which enhances lipid solubility and/or lipid miscibility of the preparation may be a source of pharmaceutically acceptable surfactants and/or fatty acids, and/or a “gastroprotective agent”. The agent which enhances lipid solubility and/or lipid miscibility of the preparation may be for example phosphatidylcholine (lecithin). Lecithin is mostly a mixture of glycolipids, triglycerides, and phospholipids (e.g. phosphatidylcholine, phosphatidylethanolamine, and phosphatidylinositol). However, in biochemistry, lecithin is usually used as a synonym for pure phosphatidylcholine, a phospholipid which is the major component of a phosphatide fraction which may be isolated from either egg yolk or soy beans from which it is mechanically or chemically extracted using hexane. It will be appreciated that the agent which enhances lipid solubility and/or lipid miscibility of the preparation may be pure phosphatidylcholine, or a mixture or mixtures of glycolipids, triglycerides and/or phospholipids (e.g. phosphatidylcholine, phosphatidylethanolamine, and phosphatidylinositol).
The preparations (or compositions) may further comprise additional components such as pharmaceutically conventional carriers, diluents, flavourings, emulsifiers and stabilisers. They may comprise additional components (for example carriers or diluents) which are “conventional” in herbal remedies.
The preparation may comprise one or more taste masking agents, for example yoghurt, fruit juice, honey and syrup.
The compositions and preparations may be suitable for oral administration. The methods of formulation of the compositions for oral administration are well known in the art. For example, the composition for administration may be prepared using a pharmaceutically acceptable carrier in a form suitable for administration. Such a composition can be prepared as a tablet, a pill, a sugar-coated agent, a capsule, a liquid, a gel, a syrup, a slurry, a suspension, etc. The carrier may be a herbal binder such as Glycyrrhiza glabra or one or more pharmaceutically acceptable carriers such as liposomes, lactose, trehalose, sucrose, mannitol, xylitol, crystalline cellulose, chitosan, calcium carbonate, talc, titanium oxide, or silica (silicon oxide) or the like.
The composition may be obtained, for example, by combining the active ingredients with a solid excipient, pulverizing the mixture (if necessary) and inserting into a capsule, for example, a soft sealed capsule consisting of a gelatin capsule, gelatin and coating (e.g., glycerol or sorbitol) or a capsule composition suitable for vegetarians. In the soft capsule, the composition may be dissolved or suspended in an appropriate liquid, such as a fatty oil, liquid paraffin or liquid polyethylene glycol, with or without a stabilizer.
The formulation (composition or preparation) may also be in the form of a standardised liquid extract. Standardised liquid extracts may in some circumstances have advantages when compared to the solid dose forms (tablets and hard shell capsules). They may involve minimal processing during manufacture and may reflect the true spectrum of the original herb (or plant etc.), in a compact and convenient form. There is also the possibility of superior bioavailability as the preparation is already in the liquid form. The prescribed dose may then be easily diluted (water, fruit juice, adding ice etc.) so as to minimise the experience of any unpleasant taste thus increasing the likelihood of patient compliance.
It will be appreciated that the preparations are suitable for other means of administration, for example mucosal delivery routes (for example rectal, nasal, vaginal) and also topical administration. The methods of formulation of the compositions for use in these methods are well known in the art.
The compositions, preparations and methods according to the invention are useful as (or in the manufacture of) pharmaceutical preparations for the treatment of human patients, and/or as (or in the manufacture of) veterinary preparations for the treatment of non-human animals, because they demonstrate activity as discussed below. The compositions may be used as (or in the manufacture of) veterinary preparations for the treatment of non-human animals, for example dogs, pigs, equine species (for example horses), poultry and reared game birds such as pheasants.
According to the present invention there is also provided a method of treatment or amelioration of a disease (or prevention of disease in at-risk groups or patients) in a human or animal subject comprising the step(s) of administering to the subject a composition comprising Ginkgo biloba , or extract or component thereof; apocynin; and a gingerol (or gingerols). The present invention also provides the use of ginkgo biloba , or extract or component thereof; apocynin; and a gingerol (or gingerols) in the manufacture of a medicament (composition) for the treatment or amelioration of a disease (or prevention of disease in at-risk groups or patients).
The method of treatment or amelioration (or prevention) of disease (or use) may be by reduction of excessive mucous production, e.g. reduction of excessive pulmonary mucous production. The method of treatment or amelioration (or prevention) of disease (or use) may (alternatively or additionally) be by treatment of abnormal (e.g. reduction of excessive) mucous production in one or more elements of the common mucosal system (such as the gastro intestinal tract and the vagina). The method or use may be for the treatment (or amelioration or prevention) of chronic obstructive pulmonary disease, CF, inflammatory disease, inflammatory respiratory disease and/or recurrent airway obstruction. The method or use may be for the treatment (or amelioration or prevention) of one or more of COPD, CF, chronic bronchitis, small airway disease, chronic bronchiolitis, laryngitis, pharyngitis, emphysema, large airway disease and/or tracheitis, asthma and/or asthma syndrome, recurrent airway obstruction, inflammatory bowel disease such as irritable bowel syndrome, bowel parasite infection, mucoid enteritis, Crohn's colitis, vaginitis, ulcerative colitis, post-operative gastrointestinal surgery, and Aspergillosis. The medicament or composition may further comprise an agent which enhances lipid solubility and/or lipid miscibility of the medicament/composition [for example phosphatidylcholine (lecithin)]. The method or use may be for the treatment (or amelioration or prevention) of disease in a human subject. The method or use may be for the treatment (or amelioration or prevention) of disease in an animal subject.
The composition may be administered to a human at a concentration, per daily dose, of Gingko biloba (standardised to gingko flavone glycosides—24%) of 1 mg/kg body weight—25 mg/kg body weight, preferably 2 mg/kg body weight—5 mg/kg body weight.
The composition may be administered to a human at a concentration, per daily dose, of a gingerol or gingerols of 60 μg/kg body weight—25 mg/kg body weight, preferably 1 mg/kg body weight—5 mg/kg body weight.
The composition may be administered to a human at a concentration, per daily dose, of apocynin of 60 μg/kg body weight—20 mg/kg body weight.
The method may further comprise the step of administering a natural form of apocynin, as described above, for example Picrorrhiza kurroa , for example, together with isolated apocynin. If Picrorrhiza kurroa is included, the preparation is administered at a concentration, per daily dose, of Picrorrhiza kurroa of 1 mg/kg body weight—35 mg/kg body weight, based on Picrorrhiza kurroa standardised to contain 10% by weight apocynin and/or androsin. If natural apocynin is included, the preparation is administered at a concentration, per daily dose, of natural apocynin of 1 mg/kg body weight—35 mg/kg body weight, based on a natural apocynin plant extract standardised to contain 10% by weight apocynin and/or androsin.
The daily dose may be provided as a single capsule, tablet or other solid or liquid form known to those skilled in the art, or may be provided in divided doses (for example 1 to 3 doses) to make up the full daily dose. The doses of gingko biloba, apocynin, and a gingerol or gingerols, may be provided together in the capsule, tablet etc, or the three may be provided as separate capsules or tablets (e.g. a capsule containing a dose or partial dose of gingko biloba, a separate capsule containing a dose or partial dose of apocynin, and a capsule containing a dose or partial dose of a gingerol or gingerols) for sequential administration.
For a veterinary preparation for treatment of allergic airways disease in a horse the composition may be administered at a daily dose, of Gingko biloba (standardised to gingko flavone glycosides—24%) of 0.5 to 5 g, for example 2 g. The composition may be administered at a daily dose, of apocynin of 0.5 to 5 g, for Example 2 g. The composition may be administered to a horse at a daily dose of gingerol (e.g. Zingiber Officinale) between 0.5 and 3 g, for example 1.5 g. The composition may be administered to a horse at a daily dose of Picrorrhiza kurroa between 4 and 10 g, for example 6 g, based on Picrorrhiza kurroa standardised to contain 10% by weight apocynin and/or androsin.
According to the invention there is provided a unit dosage form comprising between 70 and 3500 mg (for example between 100 and 200 mg) apocynin; between 70 and 3500 mg (for example between 200 and 300 mg) ginkgo biloba or extract or component thereof; and between 70 and 3500 mg (for example between 100 and 200 mg) gingerol. In a further aspect of the invention there is provided a unit dosage form comprising between 17.5 mg and 1050 mg (for example between 250 and 400 mg) natural apocynin (based on a natural apocynin [such as Picrorrhiza kurroa ] which is standardised to contain 10% by weight apocynin and/or androsin); between 8.75 mg and 525 mg (for example between 100 and 200 mg) isolated apocynin; between 70 and 3500 mg (for example between 200 and 300 mg) ginkgo biloba or extract or component thereof; and between 70 and 3500 mg (for example between 100 and 200 mg) gingerol. The unit dose may be provided as a single capsule, tablet or other solid or liquid form known to those skilled in the art.
The present invention also provides the use of a gingerol in the manufacture of a medicament for the treatment of disease (such as CF or COPD). The treatment may be by the reduction of excessive mucous production, for example excessive pulmonary mucous production. The treatment may be by the reduction of excessive allergenic mucous production, for example excessive allergenic pulmonary mucous production. The present invention also provides a method of treatment or amelioration of a disease (such as CF or COPD) comprising the step(s) of administering to the subject a composition comprising a gingerol or gingerols. The treatment may be by the reduction of excessive mucous production, for example excessive pulmonary mucous production.
According to the present invention in a further aspect there is provided a composition including (% by weight) 5-25% (for example 15 to 20%) apocynin, 10-50% (for example 30-40%) Picrorrhiza kurroa, 10-45% (for example 20 to 30%) ginkgo biloba and 10-30% (for example 15 to 25%) Zingiber officinale. The ginkgo biloba may be a standardised 24% Ginkgo flavone glycoside extract.
According to the present invention in a further aspect there is provided a composition including (% by weight) 5-25% (for example 15 to 20%) apocynin; 5 to 50% (for example 10 to 20%) component of ginkgo biloba (e.g. Ginkgolide A, B, C, J or M); and 10 to 30% (for example 15 to 25%) gingerol (e.g. 6-gingerol, 8-gingerol).
The composition may further comprise an agent which enhances lipid solubility and/or lipid miscibility (for example lecithin).
The Zingiber officinale may be a standardised 5% gingerols extract. The composition may include apocynin, Picrorrhiza kurroa , ginkgo biloba and Zinziber officianale in the ratios (% by weight), for example 18: 36: 26: 20.
The compositions (and preparations) of the invention may be used as a sole treatment. They may also be used alongside conventional medicines (e.g. anti-allergics such as steroids and antihistamines which have unwanted side effects); this may lead to a reduction in the dose of conventional medicine required and thus a reduction in likelihood/occurunce of the side effects. A reduction of side effects of a therapeutic agent (for example the side effects of anti-allergic agents) during treatment of human or animal patients being treated is known as “dose sparing”. Thus, according to the invention in a further aspect there is provided a method of dose sparing a therapeutic agent comprising the step of administering to the patient a composition comprising ginkgo biloba , or extract or component thereof; apocynin; and a gingerol (or gingerols) The composition may be administered at the same time as the therapeutic agent (for example the anti-allergic agent) or at a different time, by the same administration route, or by a different administration route. The medicament or composition may further comprise an agent which enhances lipid solubility and/or lipid miscibility of the medicament/composition [for example phosphatidylcholine (lecithin)].
DETAILED DESCRIPTION OF THE INVENTION
Examples of the present invention will now be described. In the following Picrorrhiza kurroa is obtained from SAMI Labs Limited, of Bangalore, India; apocynin (acetovanillone) is obtained from Sigma-Tau (Aldritch); ginkgo biloba and Ginger obtained from MediHerb (see above) and/or Cambridge Commodities Limited. These, lecithin, androsin, gingerols etc., and the other reagents are also widely available elsewhere.
EXAMPLE 1
The following reagents were mixed:
apocynin 180 mg Picrorrhiza kurroa 360 mg (The above mixture of isolated and natural apocynin might also be described as: Picrorrhiza kurroa 540 mg enriched to contain a minimum of 33.33% apocynin—to do so would then combine both the Picrorrhiza and apocynin) ginkgo biloba (standardised to contain 24% Ginkgo flavone glycosides) 260 mg Zingiber Officinale (standardised to contain a minimum of 5% gingerols) 200 mg The mixture was divided and prepared in a form suitable for dosing, for example, in a capsule form for oral dose.
EXAMPLE 1A
The following reagents were mixed:
apocynin 162 mg Picrorrhiza kurroa 324 mg (The above mixture of isolated and natural apocynin might also be described as: Picrorrhiza kurroa 540 mg enriched to contain a minimum of 33.33% apocynin—to do so would then combine both the Picrorrhiza and apocynin) ginkgo biloba (standardised to contain 24% Ginkgo flavone glycosides) 234 mg Zingiber Officinale (standardised to contain a minimum of 5% gingerols) 180 mg Lecithin 100 mg The mixture was divided and prepared in a form suitable for dosing, for example, in a capsule form for oral dose.
EXAMPLE 1B
The following reagents were mixed:
Apocynin: 180 mg Ginkgolide A: 60 mg 6-Gingerol: 10 mg Sodium carbonate (filler): 650 mg Lecithin: 100 mg The mixture was divided and prepared in a form suitable for dosing, for example, in a capsule form for oral dose.
EXAMPLE 1C
The following reagents were mixed:
Apocynin: 180 mg Ginkgolide B: 60 mg 6-Gingerol: 10 mg Calcium carbonate (filler): 650 mg Lecithin: 100 mg The mixture was divided and prepared in a form suitable for dosing, for example, in a capsule form for oral dose.
EXAMPLES 1D, 1E, 1F, 1G
These examples correspond with Examples 1, 1A, 1B, 1C, with the same weight of androsin substituted for the apocynin in each formulation.
The dose for adults and mature children for the reduction of excessive mucous production is 1,000 mg (two 500 mg capsules) in the morning and 1,000 mg (two 500 mg capsules) in the evening.
Administration of the above mixtures to patients with clinical histories, allergic or non-allergic, of chronic pulmonary disorders and subsequent chronic cough-related problems and which include patients with diagnosed COPD and asthma has provided significant clinical improvements which included reduction in excessive pulmonary mucous production, and reduction in coughing (both productive and non-productive). This is illustrated by the Examples, Case Studies, and Clinical Trial, below.
Concurrent with this significant reduction in excessive bronchial mucous production and subsequent reduction in coughing is a marked improvement in the reduction of breathlessness which enabled the resumption of normal daily activities such as shopping, walks and housework. A marked improvement in exercise tolerance has been reported by these patients. An improved nocturnal sleeping pattern has also been reported with minimal, if any, sleep disruption due to the need to cough and/or ‘clear the throat’ as a result of the ongoing excessive pulmonary mucous production. Increasing breathlessness and disability produces psychosocial consequences such as loss of confidence, loss of self esteem, increased dependency, social isolation, anxiety and depression. Patients after administration of the above mixture consistently report improvement in the ‘quality-of-life’ including an improved ability to socially-interact with others (‘I can now go to clubs and cafes without worry’; ‘I can walk without worry for as long as I wish’; ‘I think I might go to the gym now—thanks to these capsules’).
When patients have taken apocynin/ Picrorrhiza kurroa and ginkgo biloba in the absence of Zingiber Officinale (gingerols) there has been some clinically observed relief. A substantial clinical improvement has been observed and reported when the combination of a gingerol or gingerols with the apocynin and ginkgo biloba is used.
The remarkable increase in effect which results from the combination suggests that a synergistic clinical outcome may be obtained by the combinations.
There now follow specific case studies and a description of a clinical trial:
EXAMPLE CS1
A 23 y.o. (year old) female presented with a long term history of chronic asthma complicated by sinusitis and bronchiolitis. The patient reported consistent productive production of thick stringy mucous production requiring removal by constant productive coughing. After taking the orally administered mixture of Example 1 the patient reported a much improved quality of life with much less excessive mucous production. The patient has a nearly normal respiratory system function with minimal, if any, excessive pulmonary mucous production. Whenever the patent stops taking this orally administered mixture the historical clinical symptoms reappear.
EXAMPLE CS2
A 70 y.o. male patient presented with a confirmed diagnosed chronic COPD and a long term history of taking daily inhaled corticosteroids and bronchodilators providing a minimal clinical benefit. After several days taking the orally administered mixture of Example 1 the patient reported some improvement (within 72 hours he reported no further coughing and no further excessive pulmonary mucous production). At the end of 30 days the patient reported that at long last he felt that he was now much better with far less coughing (as a result of less excessive pulmonary mucous production). Subsequently the patient now reports a much much improved quality of life with his COPD symptoms abated.
EXAMPLE CS3
A 16 y.o. female presented with diagnosed bronchiolitis—excessive pulmonary mucous production and constant nocturnal coughing. When the patient took Zingiber officinale standardised to contain a minimum of 5% gingerols (alone) some reduction of the mucous production and coughing was observed. However the clinical problem was not resolved and the clinical improvement was thought to be marginal. When the orally administered mixture according to Example 1 was administered a marked and dramatic clinical improvement was noted.
EXAMPLE CS4
A 92 y.o female with long term COPD inadequately managed with inhaled beta agonists and corticosteroids with a history of coughing excessive sputum (excess mucous production). Example 1A was instituted into her therapeutic regime by her attending physician and a marked positive clinical improvement was observed within the first 7 days. The patient—by her own request—continues to include Example 1A into her daily COPD therapeutic regime .
EXAMPLE CS5
An 80 y.o. male with long term COPD inadequately managed with inhaled beta agonists and corticosteroids with a history of coughing and sputum production (excess mucous). Example 1A was instituted into his therapeutic regime by his attending physician and a marked positive clinical improvement was observed. The patient—by his own request—continues to include Example 1A into his daily COPD therapeutic regime.
EXAMPLE CS6
An 84 y.o. female with long term bronchiolitis (COPD) inadequately managed with inhaled beta agonists and corticosteroids and antibiotics with a history of nocturnal sputum coughing (excess mucous) and respiratory embarassment. Example 1A was instituted into her therapeutic regime. A marked positive clinical improvement was observed within the first 14 days. The patient—by her own request—continues to include Example 1A into her daily therapeutic regime.
EXAMPLE CS7
An 80 y.o. female with long term COPD inadequately managed with inhaled beta agonists and corticosteroids with a history of sputum production (excessive mucous). Example 1A was instituted into her therapeutic regime by her attending physician and a marked positive clinical improvement was observed within the first 7 days. The patient—by her own request—continues to include Example 1A into her daily COPD therapeutic regime.
EXAMPLE CS8
A 72 y.o. male with COPD syndrome stated that “Now that I've been taking the AKL III [Example 1A] for just over two weeks [. . . ] I thought you might be interested in my reactions. Within three days my chest began to feel “clearer” ie less tightness and little or no phlegm. My wife tells me I also sleep more quietly! Generally I feel better and although the chest is not quite normal (I am still a bit throaty but that may just be catarrh) I would say that there was a real improvement without doubt.”.
EXAMPLE CS9
74 y.o. female with long term COPD inadequately managed with inhaled beta agonists and corticosteroids and antibiotics with a history of non-productive coughing (excessive mucous production). Example 1A was instituted into her therapeutic regime and a marked positive clinical improvement was observed within the first 7 days. The patient—by her own request—continues to include Example 1A into her daily COPD therapeutic regime. On the occasions when she lowers the recommended dosage she notes a return of the coughing.
EXAMPLE CS10
A 28 yo Female with persistent long-term bronchitis and bronchiolitis with excessive diurnal and nocturnal sputum production (excess mucous) stated(translated direct from Spanish): “AKLIII [Example 1A] continues to work well. I can now work without problems. It appears that my body reacts very positively with respect to my respiratory functioning. Could you please continue to send me more AKL III (Example 1A) so that I might continue this fantastic path that returns me to good health.”
EXAMPLE CS11
A 74 y.o female with pulmonary Aspergillus (IgE of 950/l) inadequately clinically managed with cortisone at 8 mg per day which is elevated to 40 mg for 3 days, 32 mg for 5 days and down to 8 mg during severe outbreaks. After 7 days including Example 1A in this therapeutic regime the patient observed that her clinical symptoms (breathlessness and persistent coughing) had much improved.
EXAMPLE 2
Clinical Trial
The effectiveness of Example 1A was assessed using a randomised placebo controlled double-blinded cross-over trial (University of Aberdeen—UK).
The purpose of the study was to provide scientific evidence regarding the efficacy and safety of Example 1A, a herbal mixture, as a therapy for adult patients whose asthma remains uncontrolled on standard medication.
Methods: 32 asthmatics (7 male, median (range) age 40.5 (22-73) yrs., median (range) FEV1% predicted 87.5 (33-93)%, median (range) daily ICS dose 800 (0-4000) mcg beclomethasone) completed a 36 week randomised double blinded placebo controlled cross-over trial consisting of: four week baseline, twelve-week treatment with Example 1A or identical placebo, eight week washout and further twelve-week cross-over treatment period. The change occurring over treatment periods was observed for lung function, Asthma Control Questionnaire (ACQ), Asthma Quality of Life Questionnaire (AQLQ), Leicester Cough Questionnaire (LCQ) scores. The mean (95% Confidence Interval) individual patient changes between active and placebo periods was calculated.
Results: Trends to clinical improvements favouring active treatment were consistently seen in the patient-centred
outcomes: ACQ mean difference (active−placebo)=−0.35 (−0.78 to 0.07, p=0.10, AQLQ difference 0.42 (−0.08 to 0.93, p=0.09), LCQ difference 0.49, (−0.12 to 1.16, p=0.15). A change in ACQ and AQLQ score of 0.5 signified clinically relevant changes in asthma control or health status. On the ACQ, 28% were unchanged, 22% better on placebo and 50% better on Example 1A. On the AQLQ 29% had no change, 29% were better on placebo and 42% better on Example 1A. No significant differences in lung function were found (FEV1: (active−placebo) mean (95% CI) difference=0.01 (−0.12 to 0.14) L, p=0.9. PEF: −3 (−22 to 28) L/min, p=0.9). Nine exacerbations occurred during placebo treatment and five whilst on Example 1A. No significant treatment associated adverse events were noted.
Conclusions: The treatment was well tolerated. It is now well established that asthma symptoms correlate poorly with the level of airway obstruction as determined by the FEV1 and PEF. Following treatment, subjective improvement in asthma symptoms may occur without improvement in the level of airway obstruction. Example 1A provided consistent trends to symptom and quality of life improvements. When these were taken together a statistical significance with a 99.9% certainty was shown.
EXAMPLE 3
Study in Horses
The purpose of this study was to assess the ability of a dietary antioxidant supplement to prevent or delay the onset, decrease the magnitude of response and/or speed the recovery of lung dysfunction, clinical signs of disease, airway inflammation, and pulmonary oxidative stress in horses with recurrent airway obstruction (RAO) on exposure to organic dust.
Materials and Methods
The test horses were studied in a crossover design such that each horse received a placebo and an active supplement (Appendix 1) for 52 days with a 2-week washout-period in between. The placebo and supplement were assigned to each horse in a randomized order. The investigators were blinded to the identity of the treatments (labeled LC1 and LC2—one of which was a placebo supplement and as such a negative control and the other was the putative active supplement). After 6 weeks of supplementation horses were exposed to organic dust by stabling with straw bedding and hay for up to 3 days.
The performance of the placebo and active supplement was judged on the basis of responses in lung function, clinical examination, airway inflammation and pulmonary oxidative stress following organic dust challenge compared to responses on the placebo diet. Lung dysfunction was assessed by measuring airway reactance and airway responsiveness to histamine by forced oscillation mechanics. Clinical signs were assessed by assigning scores for respiratory rate, nasal discharge, abdominal lift/expiratory effort, nasal flaring, lung sounds and cough. Airway inflammation was determined by cytological analyses of tracheal wash and bronchoalveolar lavage fluid (BALF) samples, and by measuring the concentration of hydrogen peroxide in exhaled breath condensate (EBC). Oxidative stress was assessed by measuring the concentrations of reduced ascorbic acid, dehydroascorbate (DHA, oxidised ascorbic acid), reduced glutathione and oxidised glutathione in tracheal wash and BALF (See FIG. 1).
Results
All horses exposed to the organic dust challenge developed lung dysfunction, airway inflammation and pulmonary oxidative stress. There were no statistically significant differences between the first and second challenges for 23 of the 32 variables examined at the end-challenge time point. For the remaining variables there was an increase in BALF neutrophil numbers, EBC hydrogen peroxide concentration, end of challenge total clinical score and tracheal epithelial lining fluid (ELF) ascorbic acid redox ratio (ARR, ratio of DHA to total ascorbic acid), but a decrease in BALF mast cell numbers, and BALF and tracheal ELF concentrations of reduced ascorbic acid and total ascorbic acid, between the ends of the first and second challenges, irrespective of the order of treatment allocation.
Results of statistical analyses demonstrated that BALF ascorbic acid concentrations were higher after challenge in horses when fed LC2 compared to LC1 (FIG. 2) and that BALF DHA and ARR were lower after challenge in horses fed LC2 compared to LC1. All other parameters were not statistically significantly different between horses when fed LC1 compared to LC2.
Discussion
On the basis of these results there is evidence that when supplemented with LC2 horses had significantly less pulmonary oxidative stress than when supplemented with LC1 after exposure to organic dust. This suggests that (1) the supplement, administered in the diet, has a pulmonary effect and (2) that the LC2 supplement decreases the production or increases the consumption of reactive oxygen species. Despite significantly decreasing the severity of pulmonary oxidative stress induced by organic dust exposure, the LC2 supplement did not fully prevent pulmonary oxidative stress following organic dust exposure, which may explain the absence of significant differences between the supplements on lung function, airway inflammation or clinical examination scores. A higher dose of supplement may therefore be required to impact on these parameters. Inflammatory airway disease is a very common condition in the equine population, particularly racehorses. The LC2 supplement may have a beneficial effect on horses with this condition by decreasing pulmonary oxidative stress without contravening doping regulations.
Composition of Supplements.
EXAMPLE LC2
Active Supplement
The following table shows a list of the ingredients:
ginkgo biloba (standardized extract: Ginkgo flavone glycosides—24%) @ 2 g/day Acetovanillone @ 2 g/day Picrorrhiza kurroa @ 6 g/day Zingiber officinale (standardized extract: gingerols—5%) @ 1.5 g/day Lysoforte (lecithin) @ 1.5 g/day Molasses meal @2 g/day Lucerne meal @ 6 g/day Orange peel @ 3.5 g/day Supplement Dose/day: 25 g/day LC1 (placebo—negative control (“Comparative Example”)) Soya meal Supplement Dose/day: 25 g/day | A composition comprising ginkgo biloba or extract or component thereof; apocynin; and a gingerol. The composition may be used to treat diseases such as CF and COPD. | 0 |
BACKGROUND OF THE INVENTION
This invention pertains generally to optical seekers, and more particularly to seekers of such type having improved resolution characteristics through extended ranges of gimbal angles.
The numerical advantages in armored vehicles enjoyed by potential enemy forces and the concomitant threat of a massive armor attack has led to the development of so-called "smart" anti-armor projectiles that are capable of distinguishing between targets and are then automatically guided to a selected target. One known type of smart projectile, incorporating an infrared (IR) seeker, is launched from a cannon or howitzer removed from the forward edge of the battle area. In the terminal phase of the flight of such a projectile the IR seeker searches for, and acquires, a single target even though countermeasures may have been taken by the enemy. Obviously, then, the IR seeker must be adapted (i.e. "g-hardened") to survive the large acceleration (the high-g environment) associated with launching from a cannon.
One known type of g-hardened IR seeker, generally referred to as an optical "free gyro" (meaning free gyroscope) seeker, employs a hard coated spherical gas bearing to survive the high-g environment at launch. While the hard coated spherical gas bearing enables the optical free gyro seeker to survive high-g loads, it restricts the gimbal angle freedom to 15 degrees, thereby unduly limiting the field of view of the seeker. Furthermore, in such a seeker the refrigerated detector unit is "body-fixed" (meaning it moves relative to its associated mirrors or lenses) with the result that resolution is degraded as the gimbal angle is increased.
Obviously, in a stand-off weapon system the effects of ballistic dispersion as well as other environmental conditions, as, for example, wind and rain, will have an adverse impact on the circular error of probability (CEP) of the system. It follows, therefore, that the effectiveness of such a stand-off weapon system will be enhanced if the total field of view and resolution of the projectile seeker are augmented to permit the search for and acquisition of targets over a broader area.
SUMMARY OF THE INVENTION
With this background of the invention in mind it is therefore an object of this invention to provide a g-hardened IR seeker having an improved field of view.
It is another object of this invention to provide a g-hardened IR seeker having improved optical resolution.
These and other objects of this invention are generally attained by providing a g-hardened IR seeker wherein a g-hardened two-axis rate gyro is utilized for platform stabilization. The g-hardened two-axis rate gyro is an annular device, thereby allowing part of the optical system to be mounted within it. Mounting a portion of the optical system within the g-hardened two-axis rate gyro reduces the overall length of the seeker head, thereby allowing 30 degree gimbal angles to be realized. Small diameter journal bearings are provided on each of the gimbal axes to survive the high-g loads. Additional length reduction is achieved by modifying the conventional gimbal assembly by using the projectile housing itself as the pedestal. Diametrically opposed D.C. torque motors provided on the inner gimbal axis drive the inner gimbal with respect to the outer gimbal. The outer gimbal is driven with respect to the projectile body by means of a D.C. servo torque motor. The motor axis of the D.C. servo torque motor is concentric to the projectile axis and the outer gimbal is driven through a step-up miter or bevel gear train. The inner gimbal houses the optical system, the detector unit, and the high-g two-degree of freedom rate gyro. Because the optics and the detector unit move with the inner gimbal, the degradation of optical resolution with gimbal angle is avoided.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of this invention, reference is now made to the following description of the accompanying drawings, wherein:
FIG. 1 is a partial cross-sectional view of a g-hardened IR seeker according to this invention; and
FIG. 2 is a partial rear view of the g-hardened IR seeker of FIG. 1 but rotated 90° with respect to FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIGS. 1 and 2, a g-hardened IR seeker 10 according to this invention is shown to include an inner gimbal 11 and an outer gimbal 13. The latter is affixed to the projectile body 15 by means of a pair of journal bearings 17 and the inner gimbal 11 is attached to the outer gimbal 13 by means of journal bearings 19. The journal bearings 17, 19 enable the outer gimbal 13 and the inner gimbal 11, respectively, to survive the high-g cannon launch environment. A zinc sulfide IR dome 21 is bonded, in any convenient manner, to a mounting ring 23 which is threaded onto the projectile body 15.
A catadioptric optical system (not numbered), including a zinc sulfide corrector lens 25, a primary mirror 27, a secondary mirror 29, and a refrigerated detector unit (RDU) 31, is mounted within the inner gimbal 11. The primary mirror 27 is supported in the inner gimbal 11 and is restrained by a ring 35. The light shield 33 prevents sunlight or other extraneous energy from entering the RDU 31.
Also packaged within the inner gimbal 11 is a two-degree of freedom rate gyro (not numbered). The latter includes a motor rotor 37, having a permanent magnet 39 affixed thereto, and a stator 41. The rotor 37 and the stator 41 have complementary spherical surfaces to form a kind of universal joint. Pressurized gas from a source (not shown) is forced between the complementary spherical surfaces in a conventional manner, here through ports (not numbered), to form a hydrostatic gas bearing. The RDU 31 is contained within the stator 41 which is affixed to the inner gimbal 11. The permanent magnet 39 reacts with motor rotating coils 43 in a conventional manner so that the rotor 37 forms a gyroscopic mass whose spin axis is coincided with the longitudinal axis of the projectile body 15. The rotor 37 is spring-restrained via a spring mechanism 45 disposed between the rotor 37 and the inner gimbal housing 11. Spring decoupling bearings 47 are provided to isolate the spring mechanism 45 from the spin of the rotor 37. It will be appreciated that the spinning rotor 37 acts as an elastically restrained gyroscopic mass and therefore any angular rotation of the gyroscopic mass about its input axis, which is orthogonal to the spin axis and is in the plane of the paper, will ultimately cause a precessional movement of the rotor 37. A precessional movement of the rotor 37 appears as a rotational movement of the rotor 37 about the output axis of the two-degree of freedom rate gyro (not numbered), which is mutually orthogonal to both the spin axis and the input axis. Two axes orthogonal to each other and to the spin axis act simultaneously as input and output axes for the two-degree of freedom rate gyro (not numbered). Angle sensing coils 49 are provided to sense the position of the rotor 37 in a conventional manner.
As mentioned briefly hereinabove, the inner gimbal 11 is supported on journal bearings 19 and is driven by a pair of D.C. torque motors 50, only one of which is shown, located on opposite sides of the inner gimbal axis. The stator 51 of the torque motor 50 is affixed to the outer gimbal 13 by means of screws 53, while the rotor 55 is coupled to the inner gimbal 11. The D.C. torque motors 50 will drive the inner gimbal 11 through a gimbal angle of ±30 degrees with respect to the outer gimbal 13. An annular gimbal stop 57 is provided on the inner surface of the mounting ring 23 to engage the inner gimbal 11 at its limits.
It should be noted here in passing that as the catadioptric optical system (not numbered) and the RDU 31 are housed within the inner gimbal 11 there is no degradation in resolution with gimbal angle.
The outer gimbal 13 carries or supports the inner gimbal 11 and is driven with respect to the projectile body 15 by a D.C. servo torque motor 60 that is mounted to the projectile body 15 concentric with the projectile axis. The motor stator 61 is secured to the projectile body 15. The motor rotor 63 has attached thereto a shaft 65. Bearings 67 are provided to enable the shaft 65 and the rotor 63 to rotate relative to the projectile body 15. The other end of the shaft 65 has an angular bevel gear 69 provided thereon which engages a corresponding gear 71 provided on the outer gimbal 13. Thus, the latter is controlled by command signals applied to the D.C. servo torque motor 60 which causes the shaft 65 to rotate with respect to the projectile body 15 and results in the outer gimbal 13 being gimballed about the journal bearing 17.
It should be recognized that although the inner gimbal 11 and the outer gimbal 13 are mounted on journal bearings 17, 19, respectively, for the purposes of g-hardening, the spin decoupling bearings 47 and the bearings 67 are both ball bearings. The use of such ball bearings does not compromise the g-hardening as the loads that both the spin decoupling bearings 47 and the bearings 67 support are minimal.
Having described a preferred embodiment of this invention, it will now be apparent to those of skill in the art that many modifications may be made without departing from our inventive concepts. Thus, for example, although a catadioptric optical system was described, a refractive optical system could just as well be utilized without departing from our novel concept of utilizing a "see through" g-hardened two degree of freedom rate gyro that allows the optical system to pass directly through it. It is felt, therefore, that this invention should not be restricted to its disclosed embodiment, but rather should be limited only by the spirit and scope of the appended claims. | A gyroscopically stabilized optical seeker for use in a cannon-launched projectile is shown to include a gimbal arrangement wherein a two-axis rate gyroscope and associated torque motors are utilized to attain the requisite stabilization however such seeker is oriented with respect to such projectile, the two-axis rate gyroscope being arranged so that the complete optical system, including the detector unit, may be mounted on the inner gimbal. | 5 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the priority of U.S. Provisional Patent Application No. 62/132,795 filed on Mar. 13, 2015, the entirety of which is incorporated by reference.
BACKGROUND
[0002] The present disclosure relates generally to pencil sharpeners, and more particularly, to automatic pencil sharpeners that operate on electrical power.
[0003] Conventional automatic pencil sharpeners typically sharpen a pencil that is inserted and removed at the user's discretion. It is common for a user to leave the pencil in the sharpener longer than necessary. As a result, the pencil continues to sharpen and the pencil sharpener removes material beyond what is necessary, shortening the life of the pencil and putting unnecessary wear on the pencil sharpener. It would be advantageous to provide an automatic pencil sharpener that provides a notification to the user when the pencil reaches a desired sharpness.
SUMMARY
[0004] Briefly stated, the present invention is directed to an automatic pencil sharpener having a notification light that informs a user when a pencil reaches a predetermined sharpness. The preferred pencil sharpener is a type which contains a pencil sharpener mechanism responsive to a sharpening switch accessible within a receiver of the pencil sharpener. The pencil sharpener mechanism contains a rotary blade assembly. The rotary blade assembly automatically sharpens a received pencil to a desired sharpness.
[0005] A sharpening switch is disposed within a pencil sharpening housing and is activatable by a pencil that is inserted through an access opening into the receiver. When the pencil activates the switch, the pencil sharpener mechanism starts operating and the notification light is activated. The notification light emits a dramatic illumination in a first frequency or color. Upon a subsequent operational event, the notification light is fully illuminated at a second frequency or color to indicate to the user that the pencil is completely sharpened. The illuminations can be a constant state, or flashed or pulsed in various patterns. In one embodiment, the notification light employs LEDs that illuminate in green and then illuminate in red.
[0006] In one embodiment, the pencil sharpener comprises a housing assembly having a pencil receiver extending from a first end at an exterior access opening to a second end. The access opening accommodates a pencil. A pencil sharpening mechanism is disposed in the housing assembly proximate the second end. A sharpening switch is disposed in the housing assembly and positioned to detect the presence of a pencil in the receiver. A notification light module is disposed in the housing assembly and, upon illumination, is configured to emit light visible exteriorly from the housing assembly. A control unit is operably connected to the sharpening mechanism, the sharpening switch and the notification light module, wherein when a pencil is inserted into the receiver and engages the sharpening switch, the control unit powers the pencil sharpening mechanism and causes the notification light module to illuminate.
[0007] The notification light module comprises an LED and the housing assembly has a light transmissive portion wherein light emitted from the LED is transmitted through the portion. The notification light module is preferably disposed for emitting light in the vicinity of the access opening. The pencil sharpener also comprises a switch which is activatable upon sharpening the pencil at a second position indicative of a substantially completely sharpened pencil. The notification light module comprises at least two LEDs, one LED being illuminated upon activation of the first sharpening switch and a second LED being illuminated upon activation of the second switch. The first LED emits at a first frequency which is preferably in the green range, and the second LED emits at a second frequency which is preferably in the red range. The first LED may be pulsed and the second LED may emit radiation at a steady state. The illumination from the first LED and the illumination from the second LED are generally disposed for transmission about the access opening.
[0008] The pencil sharpener may further comprise a blade guard having an upper portion, and LEDs are mounted to the circuit board disposed at an upper portion of the blade guard assembly. The blade guard assembly further includes an axial conduit which extends from the lower portion to the upper portion. A wire extends through the conduit for connecting an LED circuit board assembly to a second circuit board assembly disposed in the housing assembly.
[0009] In another embodiment, the pencil sharpener comprises a housing assembly having a receiver adjacent a first end at an exterior access opening and extending to a second end. The access opening accommodates a pencil. The housing assembly has a notification light which, upon activation, is visible exteriorly of the housing assembly. A pencil sharpener mechanism is mounted to the assembly proximate the second end. A sharpener control circuit is operatively connected to a sharpening switch and the sharpening mechanism. When a pencil is inserted in the receiver and the sharpening switch is activated, the sharpening control unit powers the pencil sharpener mechanism to sharpen a pencil and illuminates the notification light in a first color and at a subsequent time when the pencil sharpener mechanism is operating and the pencil is substantially completely sharpened, the sharpening control unit illuminates the notification light in a second color.
[0010] The notification light is preferably disposed adjacent the access opening. When the pencil is withdrawn from the receiver, the notification light ceases illumination.
[0011] In various embodiments, the notification light can sequentially illuminate two distinct frequencies or colors, can illuminate an arcuate section and effectively rotate the section along the circumference of the notification light over time, and can fully illuminate at a pre-established event or time.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a perspective view, partly in schematic, of a pencil sharpener incorporating a notification light;
[0013] FIG. 2 is a front elevational view of the pencil sharpener of FIG. 1 ;
[0014] FIG. 3 is a rear elevational view of the pencil sharpener of FIG. 1 ;
[0015] FIG. 4 is a top plan view of the pencil sharpener of FIG. 1 ;
[0016] FIG. 5 is a perspective view, partly in schematic, of the pencil sharpener of FIG. 1 with the cover removed;
[0017] FIG. 6 is a perspective view of the pencil sharpener of FIG. 1 with the cover removed and partially exploded;
[0018] FIG. 7 is a schematic circuit diagram for a control circuit for the pencil sharpener of FIG. 1 ;
[0019] FIG. 8 is a schematic circuit diagram for a second embodiment of a control circuit for the pencil sharpener of FIGS. 1 ; and
[0020] FIG. 9 is an enlarged sectional view, partly in schematic and portions removed, of an interior portion of the pencil sharpener of FIG. 1 .
DETAILED DESCRIPTION
[0021] Referring to FIGS. 1-4 , wherein like numerals indicate like elements throughout, there is shown a representative embodiment of an automatic pencil sharpener 10 . The pencil sharpener 10 , in accordance with the present disclosure, automatically sharpens a pencil 12 to a predetermined sharpness and illuminates a notification light (schematically illustrated in FIGS. 1 and 5 ) at a pre-established operational time to inform the user that the pencil is at the predetermined sharpness. The pencil sharpener is preferably adapted to be positioned on a desktop or other horizontal surface in an upright orientation for use as needed.
[0022] Referring to FIG. 1 , an embodiment of the pencil sharpener 10 includes an upright housing assembly 20 with a removable cover 21 . The housing assembly 20 has a generally vertical central receiver 22 having a first end 24 and a tapered second end 26 . The receiver 22 receives a pencil to be sharpened. The receiver 22 is configured to receive a pencil 12 through access opening 28 at the first end 26 . The housing assembly 12 contains a pencil sharpener mechanism 30 with a rotatable blade assembly 32 having at least one rotatable helical blade driven by a motor 34 operatively responsive to a sharpening switch 36 ( FIGS. 4, 8 and 9 ). The pencil sharpener mechanism 30 is disposed for operation at the second end 26 of the receiver 22 and is configured to sharpen the pencil to a desired sharpness. An illuminatable notification light module 40 is disposed at an upper location. Power for the pencil sharpener is preferably supplied by a wall socket-mounted, power supply cord connecting at socket 29 .
[0023] The rotary blade assembly 32 has a plurality of cutting surfaces, which may be straight or curved. The rotary blade assembly 32 is supported at an angle obliquely oriented relative to the central axis of receiver 22 and functions to produce the sharpened point configurations of the pencil. The central axis of the receiver 22 is vertical in the disclosed embodiment, but may have a different orientation in other embodiments. In one embodiment, the pencil sharpener mechanism 30 is supported by a safety spring (not depicted) to prevent damage to the pencil sharpener 10 due to excessive or improper use.
[0024] With reference to FIGS. 5 and 6 , the cover 21 which retains the shavings from the sharpened pencils has been removed to reveal the blade assembly 32 and certain features of the notification light module 40 . A platform 42 supports a stepped cylindrical case 44 which encloses at least some portions of the motor 34 and the linkage/mechanical connections with the blade assembly 32 . A blade housing 50 which has angularly spaced, inverted U-shaped openings 52 is supported on the top edge 46 of the case. The top of the housing has an integral quasi-cylindrical coupler neck 60 . A light transmissive cap 70 , which may be translucent and/or transparent, includes a central opening defining access opening 28 for the pencil access to the receiver 22 . The light transmissive cap 70 includes a reduced generally cylindrical side 72 with a resilient snap tab 74 . The snap tab 74 is received in a complementary recess 64 at the interior of the coupler neck 60 to secure the cap 70 to the blade housing 50 . In some embodiments, the cap 70 may be partially or completely transparent.
[0025] An LED printed circuit board assembly 80 is located at an upper location of the blade housing interior and has a central opening to accommodate the inserted pencil. The circuit board 80 mounts at least one LED. When the cap 70 is snapped in place on the blade housing 50 , the printed circuit board assembly is located under the light transmissive cap 70 so that at least one LED is positioned to emit light through the cap.
[0026] A tunnel-like conduit 56 extends from the interior of the sharpener base axially to the top of the blade housing. Electrical wires 82 connect the main printed circuit board assembly 90 located in the housing base with the LED printed circuit board 80 . The cap 70 has a radially projecting brim 76 which projects to cover the end of the conduit when the cap is snapped into place.
[0027] The LED circuit board assembly 80 preferably includes at least two LEDs 84 and 86 which emit at different frequencies. When the LEDs are energized, they illuminate at preferably different frequencies, such as, for example, in the green range for LED 84 and the red range for LED 86 . The LEDs illuminate through the top of the translucent and/or transparent cap 70 to provide the notification light which is readily visible exteriorly of the pencil sharpener.
[0028] Various LED configurations and illumination patterns may be provided. Three pairs of angularly spaced LEDs may be provided as schematically illustrated in FIG. 7 for LED circuit board assembly 81 .
[0029] In one embodiment (not illustrated), the three different LEDs are provided; a green LED, a red LED and a yellow LED. In some embodiments, the LEDs illuminate in a steady state illumination pattern. In other embodiments, one or more of the LEDs are pulsed. In other embodiments three angularly spaced pairs of LEDs are provided and a sequential illumination pattern is provided.
[0030] In one preferred operation, a green LED flashes during sharpening as detected by switch 36 . A red LED illuminates in a steady state when the motor keeps rotating and the completed sharpening has been detected by switch 38 . Naturally, other LED frequencies and patterns and sequences may be provided.
[0031] A sharpener control circuit 90 selectively connects via switches 36 and 38 with the motor 34 for the blade assembly 32 . A green LED 84 and a red LED 86 are disposed in parallel. When the first switch 36 is tripped by inserting the pencil into the sharpener, a microprocessor 88 causes the green LED 84 to pulse. When the second switch 38 is tripped by virtue of the pencil being sufficiently sharpened and the motor continues operating, the red LED 86 is illuminated. Upon removal of the sharpened pencil from the sharpener, both the green LED 84 and the red LED 86 cease illumination.
[0032] When the switch 36 is depressed by the tip of a pencil (not depicted), the sharpener control circuit 90 also begins to operate the pencil sharpener mechanism 30 and illuminates the notification light module 40 at the first color. Upon activation of switch 38 , the sharpener control circuit 90 switches the notification light to the second LED color 86 . The pencil sharpener mechanism 32 continues to operate as long as the switch 38 is depressed. When the pencil is removed from contact with the switch 38 the switch 38 , returns to its original “off” position and the notification light module 40 ceases illumination and the pencil sharpening mechanism 30 ceases operating.
[0033] In one embodiment, a notification light module generates an illumination annulus coaxially surrounding the access opening 28 and sequentially illuminates in two distinct colors. Initially, the notification light module partially illuminates a first color along an arcuate section when the pencil engages the pencil sharpener mechanism switch 36 . If the pencil remains engaged with the pencil sharpener mechanism switch, the notification light module continues illuminating the first color, and the arcuate section rotates about the access opening 28 in the circumferential direction over time until the entire annulus of the notification light is illuminated in the first color. At a set time or when switch 38 is activated, the entire annulus of the notification light is illuminated in a second color. Naturally, multiple LEDs are required.
[0034] In the preferred depicted embodiments, the first color is green and the second color is red. The set time may be adjusted by the user to ensure that a desired sharpness of pencil is consistently achieved. In one embodiment, two separate notification lights are used in which each is illuminated in one of the two colors.
[0035] While preferred embodiments have been set forth for purposes of illustration, the foregoing descriptions should not be deemed a limitation of the invention herein. Accordingly, various modifications, adaptations and alternatives may occur to one skilled in the art without departing from the spirit and the scope of the present invention. | An automatic pencil sharpener includes a pencil sharpening mechanism and a sharpening switch within a central receiver configured to receive a pencil through an access opening. The pencil sharpening mechanism and sharpening switch are operatively connected to a sharpener control unit. When a pencil actuates the sharpening switch, the sharpening control unit powers the pencil sharpening mechanism and the notification light illuminates in a first color. At a subsequent event or time when the pencil is substantially fully sharpened, the notification light illuminates in a second color. The illumination is preferably produced by at least one green LED and one red LED. | 1 |
RELATED APPLICATION
The present application claims the benefit of U.S. Provisional Application No. 61/761,043, filed Feb. 5, 2013 entitled “HIDEOUT UTILITY TEST STATION AND MARKER,” which is incorporated herein in its entirety by reference.
FIELD OF THE INVENTION
The invention relates generally to marker posts and more specifically to a marker post disposed below the ground with a top metal plate that is easily locatable, and a removable cap that provides access to a tracer station.
BACKGROUND OF THE INVENTION
Traditionally, marker posts are used to place as an above the ground warning that an underground pipe or electric line is buried in the soil. The marker post must be somewhat visually and physically unobtrusive, yet be able to warn a person that an underground utility exists at the particularly marked location. In addition, the marker post must be able to withstand the environment for an extended period of time. The marker post should also be able to remain embedded at the location of the underground utility in order to continue to convey a warning message of the existence of an underground hazard to those who may be in the proximity of the underground hazard.
One problem with traditional marker posts is that once embedded, those marker posts stand a good chance of being up-lifted due to a variety of reasons such as by individuals who are in the proximity of the marker post or by nature, such as due to severely windy storms. In addition there is a need for a marker that contains a tracer or test station.
SUMMARY OF THE INVENTION
The invention substantially addresses the aforementioned needs of the industry. The post system of the present invention is formed from a cap and a base. The cap sits flush with the ground while base system extends into the ground towards the underground hazard. The cap is removable to access a tracer station or similarly-mounted integrated steel plate. The cap includes a superior disk, a cap housing, and a locking mechanism. The base includes an anchor system and two telescoping assemblies nested within the base so as to raise the test station or steel plate above ground level.
The superior disk includes a top surface, a bottom surface, a lip, a first aperture, and second apertures. It should be understood that the superior disk can be customized, as required by application, including shape, or thickness. The superior disk can embody a circular, oval, or other closed curve shape. The superior disk can embody a triangular, square, or other polygonal shape. The superior disk can embody a variety of profiles including flat, concavo-convex, a convex-convex, or a concavo-concave shape. In addition, the top surface of the superior disk can be customized to include proper labeling for applications including but not limited to use of the post system with water, gas, and fiber optic utilities. The first aperture of the superior disk can be used for operably coupling the locking mechanism. The second apertures of the superior disk can be used for operably coupling the superior cap to the receiving disk.
The cap housing includes a receiving disk and a casing. The receiving disk includes a first aperture and second apertures. It should be understood that the receiving disk can be customized, as required, including, shape or thickness. The receiving disk can embody a circular, oval, or other closed curve shape. The receiving disk can embody a triangular, square, or other polygonal shape. The receiving disk can embody a variety of profiles including flat, concavo-convex, a convex-convex, or a concavo-concave shape. The first aperture of the receiving disk can be used for operably coupling the locking mechanism. The second apertures of the receiving disk can be used for operably coupling the receiving disk to the superior disk. The casing may be customized to embody a closed curve, or polygon tube structure.
It is further envisioned that the receiving disk and the superior disk could be a singular unit disk molded on to the casing unit. A warning label could then be affixed to the uppermost surface of the disk.
The locking mechanism includes a bolt and a locking assembly. It should be understood that the locking assembly can be customized as required depending upon application. The bolt of the locking mechanism may be any standard bolt suitable for use with the cap of the post system. The locking assembly can include a first washer, a first nut, a second washer, a locking arm, and a final nut. In assembly the cap of the bolt rests upon the top surface of the superior disk, with the thread portion of the bolt extended downward into the casing. The washers, nuts, and locking arm may then be assembled onto the bolt.
The base includes a base housing, an anchor, a first internal telescoping arm, and a second internal telescoping arm. The base housing, first internal telescoping arm, and second internal telescoping arm may be customized, as required by application, to embody a closed curve, or polygon tube structure. The cap fits about the top end of the base unit thus sealing off the interior passage of the base from the elements.
The base housing includes a lower internal stop, anchoring wings, and an aperture. The lower internal stop acts as a catch or safety that prevents the internal telescoping arms from sliding out of the bottom of the housing. The base housing may include an upper internal lip or stop that acts as a catch or safety that prevents the internal telescoping arms from sliding out of the top of the housing. The anchoring wings act as a security feature for the post system. In use the anchoring wings are hinged to the housing at the bottom of the wing and extend outward from the housing. When the housing is pulled upwards the anchoring wings engage the surrounding environment and prevent removal of the post system. It should be understood that the anchoring wings may be of any shape or form as the application may require. The aperture of the base housing allows the locking arm of the locking mechanism to pass through the base thereby securing the cap to the base.
The first internal telescoping arm include may include a lower internal stop, a lower external lip, and an upper internal lip. The lower internal stop acts as a catch or safety that prevents the second internal telescoping arms from sliding out of the bottom of the housing. Alternatively, the base housing lower internal stop may act as a catch of safety for the second internal telescoping arm as well. There may also be a lower external lip that acts as a catch or safety that prevents the internal telescoping arms from sliding out of the top of the housing. The upper internal lip acts as a catch or safety that prevents the second internal telescoping arm from sliding out of the top of the housing.
The first internal telescoping arm may be of two piece construction having a first element with a smaller perimeter than the second element, i.e. in a wedding cake design. Conversely, the first internal telescoping arm may be a single molded piece.
The second internal telescoping arm sits within the first internal telescoping arm. The second internal telescoping arm includes a terminal board and anchoring holes. It may also include a lower external lip that acts as a catch or safety that prevents the internal telescoping arms from sliding out of the top of the housing. The terminal or tracer board functions as a location where the user may anchor, as an example, tracer wires for underground utilities by way of the anchoring holes.
In use, the post system described herein allows the user access to the tracer lines of underground utilities for testing continuity and integrity of the utilities. The cap is removed by loosening a fastener which rotates the lock mechanism. The cap is then removed from the housing. The tracer board or steel plate can be lifted axially from the housing due to the telescoping arms.
BRIEF DESCRIPTION OF THE DRAWINGS
The embodiments of the present invention may be more completely understood in consideration of the following detailed description of various embodiments in connection with the accompanying drawings, in which:
FIG. 1 is a perspective view of post system according to an embodiment.
FIG. 2 is a top view of the post system.
FIG. 3 is a perspective view from the base of the post system.
FIG. 4 is a perspective view showing the interior of the base housing and telescoping arms, of an embodiment.
FIG. 5 is a perspective view of the cap.
FIG. 6 is a plan view showing the lock bolt, the receiving disk and the superior disk of the cap.
FIG. 7 is a sectional view of a locking mechanism of a cap, of an embodiment.
FIG. 8 is a perspective view of the housing base with cap attached, of an embodiment.
FIG. 9 is a perspective view of the internal telescoping arms with cap removed.
FIG. 10 is a perspective view of the internal telescoping arms.
FIG. 11 is a perspective view of the present invention placed in the ground.
While the present invention is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail herein. It should be understood, however, that the intention is not to limit the present invention to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present invention.
DETAILED DESCRIPTION
Referring to FIGS. 1-10 , a post system 100 comprises, in an embodiment, cap 102 and base 104 , wherein cap 102 operably couples to base 104 . In an embodiment, cap 102 generally comprises superior disk 106 , cap housing 108 , and a locking mechanism 110 . Superior disk 106 includes aperture 112 configured to operably couple locking mechanism 110 . Superior disk 106 further comprises one or more apertures 114 for operably coupling superior disk 106 to cap housing 108 . Superior disk 106 further comprises top surface 116 wherein top surface 116 can comprise any suitable contour, including, but not limited to, the central portion of top surface 116 being superior to, or inferior to, the outer portion of top surface 116 creating a concave or convex disk. Superior disk 106 further comprises bottom surface 118 , wherein bottom surface 118 can comprise any suitable contour, including, but not limited to, the central portion of bottom surface 118 being superior to, or inferior to, the outer portion of bottom surface 118 creating a concave or convex disk. In an embodiment bottom surface 118 is flat. In another embodiment, bottom surface 118 matches top surface 116 .
Superior disk 106 further comprises lip 120 wherein lip 120 can embody any suitable height and may be in any suitable form such that superior disk 106 can comprise a disc of varying thickness, depending on the application or embodiment. In an embodiment, lip 120 is a closed curve wherein superior disk 106 forms a circular, oval, or other like disk. In a further embodiment lip 120 is a polygon wherein disk 106 forms a triangle, square, rectangle, or other like disk.
Referring specifically to FIGS. 5 and 6 , cap housing 108 comprises receiving disk 122 and casing 124 , wherein receiving disk 122 is configured to receive superior disk 106 , and casing 124 is configured to receive elements of base 104 . In an embodiment, receiving disk 122 can include an aperture configured to operably couple locking mechanism 110 . Receiving disk 122 further comprises one or more openings 125 configured to operably couple cap housing 108 to superior disk 106 . Receiving disk 122 further comprises top surface 127 wherein top surface 127 can comprise any suitable contour, including, but not limited to, the central portion of top surface 127 being superior to, or inferior to, the outer portion of top surface 127 creating a concave or convex disk. Receiving disk 122 further comprises bottom surface 126 , wherein bottom surface 126 can comprise any suitable contour, including, but not limited to, the central portion of bottom surface 126 being superior to, or inferior to, the outer portion of bottom surface 126 creating a concave or convex disk. In an embodiment, bottom surface 126 is flat. In a further embodiment, bottom surface 126 matches top surface 127 .
Receiving disk 122 further comprises lip 128 wherein lip 128 can comprise any suitable height and may be in any suitable form. In an embodiment lip 128 is a closed curve wherein receiving disk 122 forms a circular or other like disk. In a further embodiment lip 128 is a polygon wherein superior disk 106 forms a triangle, square, rectangle, or other like disk. In an embodiment, surfaces 118 , 127 , and 128 are flat.
Casing 124 comprises aperture 136 , and channel 140 . Aperture 136 is configured to receive locking arm 150 . In an embodiment casing 124 is a closed curve wherein casing 124 forms a circular, oval, or other like tube. In a further embodiment casing 124 is a polygon wherein casing 124 forms a triangular, square, rectangular, or other like tube. The circumference, in the case of a closed curve, or the perimeter, in the case of a polygon, of casing 124 is such that channel 140 configured to receive components of base 104 , as will be described.
Referring to FIG. 7 , locking mechanism 110 comprises bolt 142 , bolt cap 143 , washer 144 , nut 146 , washer 148 , locking arm 150 , and nut 152 . Locking mechanism 110 is assembled by passing bolt 142 through aperture 112 and the aperture of receiving disk 122 so that bolt cap 143 rests of top surface 116 . Washer 144 is then placed onto bolt 142 , followed by nut 146 , washer 148 , locking arm 150 , and finally nut 152 . Locking mechanism 110 is configured to allow a user to fasten cap 102 to base 104 by allowing user to manipulate or turn bolt cap 143 thereby causing locking arm 150 to pass through aperture 136 and aperture of base 104 , as will be described.
Referring to FIG. 7 , locking mechanism 110 comprises bolt 142 (not shown), bolt cap 143 , washer 144 , nut 146 , washer 148 , locking arm 150 , and nut 152 . Locking mechanism 110 is assembled by passing bolt 142 through aperture 112 and the aperture of receiving disk 122 so that bolt cap 143 rests of top surface 116 . Washer 144 is then placed onto bolt 142 , followed by nut 146 , washer 148 , locking arm 150 , and finally bolt 152 . Locking mechanism 110 is configured to allow a user to fasten cap 102 to base 104 by allowing user to manipulate or turn bolt cap 143 thereby causing locking arm 150 to pass through aperture 136 and aperture of base 104 , as will be described.
Referring generally to FIG. 8-10 , base 104 generally comprises base housing 154 , first internal telescoping arm 162 , and second internal telescoping arm 170 .
Referring specifically to FIG. 8 , in an embodiment base housing 154 can comprise aperture 155 , anchoring wings 156 , channel 158 , and aperture 163 . Aperture 155 is configured to accept locking arm 150 when post system 100 is locked. Anchoring wings 156 are elements of base housing 154 articulated at joint 157 and free of base housing 154 throughout their perimeter 161 , so that anchoring wings 156 are rotated distal to housing 154 . When in use, as illustrated in FIG. 10 , anchoring wings 156 function as a security feature and are configured to prevent post system 100 from being pulled from the ground. As post system 100 is pulled in an upward direction using, as an example, cap 102 , anchoring wings 156 engage their surrounding, as an example, soil, and prevent post system 100 from being pulled from the environment in which post system 100 has been installed. Though depicted as curved in FIG. 5 anchoring wings 156 can comprise any suitable shape or configuration depending upon the application or use of post system 100 . Base housing 154 may also include access holes 190 for tracer wire or utilities.
Channel 158 is configured to accept first internal telescoping arm 162 . Lower internal stop 159 is internal to housing 154 . In an embodiment lower internal stop 159 may be a single flange or other protuberance that partially block aperture 163 . In the alternative, internal stop 159 maybe a lip that runs the circumference, in the case of a closed curve, of aperture 163 . Lower internal stop 159 is configured to provide a stop for first internal telescoping arm 162 so that when installed or in transport first internal telescoping arm 162 will not slide through aperture 163 . It is envisioned that other stops could be inserted into aperture 163 to prevent internal telescoping arms from being removed out of the top of the base housing.
In an embodiment, base housing 154 is a closed curve wherein base housing 154 forms a circular, oval, or other like tube. In a further embodiment housing 154 is a polygon wherein housing 154 forms a triangular, square, rectangular, or other like tube. The circumference, in the case of a closed curve, or the perimeter, in the case of a polygon, of housing 154 is such that channel 158 is configured to receive first internal telescoping arm 162 .
Referring specifically to FIGS. 9 and 10 , first internal telescoping arm 162 includes channel 165 , lower section 164 , and upper section 166 .
In an embodiment, first internal telescoping arm 162 is a closed curve wherein first internal telescoping arm 162 forms a circular, oval, or other like tube. In a further embodiment first internal telescoping arm 162 is a polygon wherein first internal telescoping arm 162 forms a triangular, square, rectangular, or other like tube. In an embodiment the circumference, in the case of a closed curve, 162 is such that channel 165 is configured to accept second internal telescoping arm 170 . In another embodiment the perimeter, in the case of a polygon, of first internal telescoping arm 162 is such that channel 165 is configured to accept second internal telescoping arm 170 . Lower section 164 is fastened to upper section 166 . Lower section 164 has a greater cross sectional area then upper section 166 so that there is a staggered outside dimension to first internal telescoping arm 162 .
Second internal telescoping arm 170 in includes channel 173 , terminal board 174 , and anchoring slots 176 . Second internal telescoping arm 170 slidingly engages first internal telescoping arm 162 . Second internal telescoping arm 170 is disposed within channel 165 of the first internal telescoping arm.
In an embodiment, terminal board 174 is mounted to second internal telescoping arm 170 at a first end and extends axially from second internal telescoping arm 170 . In an embodiment, terminal board 174 is an exposed internal flat, in the case of a polygon, surface of second internal telescoping arm 170 wherein anchoring slots 176 are located. Anchoring slots 176 serve to provide a location for connecting, in one embodiment, a tracer wire to terminal board 174 , and may be in any shape or diameter depending on the application or embodiment.
In an embodiment, second internal telescoping arm 170 is a closed curve wherein internal second internal telescoping arm 170 forms a circular, oval, or other like tube. In a further embodiment first internal telescoping arm 162 is a polygon wherein second internal telescoping arm 170 forms a triangular, square, rectangular, or other like tube. The circumference, in the case of a closed curve, is such that channel 165 is configured to accept second internal telescoping arm 170 . The perimeter, in the case of a polygon, of second internal telescoping arm 170 is such that channel 165 is configured to accept second internal telescoping arm 170 .
In operation, assembly of post system 100 can comprise, inserting first internal telescoping arm 162 into aperture 155 of base housing 154 , inserting second internal telescoping arm 170 into aperture 167 of first internal telescoping arm 162 thereby forming base 104 , operably coupling superior disk 102 to receiving disk 122 , operably coupling internal locking mechanism 110 to superior disk 102 and receiving disk 122 thereby forming cap 102 , and operably coupling cap 102 to base 104 wherein base 124 of cap 102 is inserted into aperture 155 of base housing 154 thereby forming post system 100 .
In operation, installation of post system 100 can comprise, forming a void by, as an example, digging hole in the ground, inserting base 104 into the void, securing base 104 within the void by, as an example, packing dirt around base 104 , coupling cap 102 to base 104 as described above, and locking cap 102 to base 104 as described above. | The post system of the present invention is formed from a cap and a base. The cap sits flush with the ground while the base system extends into the ground towards the underground hazard. The cap is removable to access a tracer station or similarly-mounted integrated steel plate. The cap includes a superior disk, a cap housing, and a locking mechanism. The base includes an anchor system and two telescoping assemblies nested within the base so as to raise the test station or steel plate above ground level. | 6 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application is a divisional of and claims the benefit of U.S. patent application Ser. No. 09/967,923, filed Oct. 2, 2001, the entire disclosure of which is incorporated by reference herein.
STATEMENT OF GOVERNMENT SUPPORT
[0002] This invention was made with U.S. Government support under Grant Number NOI-LM6-3544 awarded by the National Institutes of Health and Grant Number DAMDI7-94-V-4015 awarded by the Department of Defense. The U.S. Government has certain rights in the invention.
BACKGROUND OF THE INVENTION
[0003] 1. Field of Invention
[0004] The invention generally relates to using a distributed network to clinically manage chronic illnesses.
[0005] 2. Description of Related Art
[0006] Managing chronic illnesses is both costly and difficult. Both patients and healthcare practitioners wish to decrease costs and inconvenience by reducing unnecessary clinic visits. However, the management quality of a chronic illness increases with the frequency that the clinical data obtained from the patient is updated. Automated and manual medical devices may be operated by a patient to provide the updated clinical data. However, the patient can operate the device improperly or has little opportunity to supply the clinical data to the healthcare practitioner.
[0007] For example, U.S. Pat. No. 6,039,688 to Douglas et al. describes a therapeutic behavior modification program, compliance monitoring and feedback system. This system provides a series of milestones for patients to achieve to maintain good health. Patients may access the system over the Internet to review compliance data and to receive motivation. This system is designed around a community support motif that allows the patient to access various graphic representations of a community to access different parts of the system.
SUMMARY OF THE INVENTION
[0008] However, patients with chronic illnesses often resist using such systems as that described in the 688 patent because such systems often feel impersonal. Patients also often fail to supply the clinical data through the conventional automated and manual medical devices, again due to the impersonal nature of the systems used to supply such data to the healthcare practitioner. Thus, while such systems provide the ability to manage a chronic illness using a distributed network to supply the necessary clinical data from the patient to the healthcare practitioner and to communicate information to and from the patient, patients with chronic illnesses often tend to avoid using such systems.
[0009] Rather, patients with chronic illnesses often strongly tend to prefer actually visiting a clinic dedicated to managing the healthcare of patients with such chronic illnesses. At such actual clinic visits, the patient interacts with various nurses and other healthcare management staff members and, most importantly, with a personal healthcare practitioner with whom the patient has developed a relationship. However, such actual clinic visits are expensive for healthcare insurers and are burdensome for patients with chronic illnesses to make at the needed frequency.
[0010] This invention provides systems and methods that provide a graphical user interface-based clinical management that simulates an actual visit to a physical clinic directed to managing a chronic illness.
[0011] This invention separately provides systems and methods that increase patient compliance by replicating the experience of the patient visiting an actual clinic directed to managing a chronic illness.
[0012] In various exemplary embodiments of the systems and methods according to this invention, the patient interacts with the clinical management system via a series of graphical user interface screens accessed over a distributed network. Various initial graphical user interface screens replicate the experience of actually visiting a clinic directed to a particular chronic illness. Additional graphical user interface screens allow the patient having a chronic illness to submit updated clinical information to the clinical management system. Various other graphical user interface screens allow the patient having a chronic illness to communicate with that patient's personal healthcare practitioner as well as various staff members of the clinic that are involved with that patient in managing that patient's chronic illness. Various other graphical user interface screens provide management information to the patient usable to aid the patient in managing that patient's chronic illness, such as warnings, information and care reminders.
[0013] Still other various exemplary graphical user interface screens allow a patient having a chronic illness to access current and archived information regarding that chronic illness, such as new findings, management advice and the like.
[0014] In various exemplary embodiments, the clinical management system may be used to manage a plurality of different chronic illnesses. As is well known in the art, patients having one chronic illness often develop one or more additional chronic illnesses. In this case, the patient having multiple chronic illnesses can use a single clinical management system to manage all of that patient's chronic illnesses using a consistent metaphor for the various chronic illnesses. In various exemplary embodiments, while different specific information may be provided depending on the type of chronic illness, the information is provided using a consistent look and feel to the graphical user interface screens. However, to distinguish between different types of chronic illnesses, in various exemplary embodiments, when dealing with a particular chronic illness, the graphical user interfaces have at least one appearance characteristic that is modified to visually indicate the particular chronic illness to which that screen currently applies. For example, in various exemplary embodiments, the appearance of the graphical user interface screens can be color coded depending on the particular chronic illness.
[0015] In various exemplary embodiments, to allow a patient who has multiple chronic illnesses to easily determine which chronic illness is being managed, an elevator metaphor is used that replicates the organization of an actual clinic into separate floors for each different chronic illness.
[0016] These and other features and advantages of this invention are described in, or are apparent from, the following detailed description of various exemplary embodiments of the systems and methods according to this invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Various exemplary embodiments of this invention will be described in detail, with reference to the following figures, wherein:
[0018] FIG. 1 is a block diagram of one exemplary embodiment of a chronic illness management system according to this invention;
[0019] FIG. 2 is a block diagram showing in greater detail one exemplary embodiment of the clinic system of the chronic illness management system of FIG. 1 ;
[0020] FIG. 3 shows one exemplary embodiment of a screen of a graphical user interface showing a virtual clinic according to this invention;
[0021] FIG. 4 shows one exemplary embodiment of a screen of a graphical user interface representing a lobby of the virtual clinic of FIG. 3 ;
[0022] FIG. 5 shows one exemplary embodiment of a screen of a graphical user interface representing an open door to a public library of the virtual clinic of FIG. 3 ;
[0023] FIG. 6 shows various exemplary embodiments of portions of a graphical user interface screen representing bulletin board notices according to this invention;
[0024] FIG. 7 shows one exemplary embodiment of a screen of a graphical user interface representing a clipboard of the lobby of FIG. 4 ;
[0025] FIG. 8 shows one exemplary embodiment of a screen of a graphical user interface representing an elevator metaphor according to this invention;
[0026] FIG. 9 shows one exemplary embodiment of a screen of a graphical user interface representing an opened elevator door showing a virtual clinic for a specific chronic illness according to this invention;
[0027] FIG. 10 shows a first exemplary embodiment of a main patient data screen of a graphical user interface according to this invention for a patient having diabetes;
[0028] FIG. 11 shows one exemplary embodiment of an on-screen contextually relevant message displayed over information displayed on the main patient data screen of FIG. 10 ;
[0029] FIG. 12 shows one exemplary embodiment of an update patient information form screen according to this invention;
[0030] FIG. 13 shows one exemplary embodiment of a screen of a graphical user interface usable to access an educational article according to this invention;
[0031] FIG. 14 shows one exemplary embodiment of a screen of a graphical user interface usable to display a tabular representation of hypoglycemic and/or hyperglycemic events according to this invention;
[0032] FIG. 15 shows one exemplary embodiment of a patient supplied data screen of a graphical user interface usable to display a blood sugar log according to this invention;
[0033] FIG. 16 shows one exemplary embodiment of a screen of a graphical user interface usable to display a date selection graphic according to this invention;
[0034] FIG. 17 shows one exemplary embodiment of a screen of a graphical user interface usable to display a linear graph according to this invention;
[0035] FIG. 18 shows one exemplary embodiment of a screen of a graphical user interface usable to display histograms according to this invention;
[0036] FIG. 19 shows one exemplary embodiment of a screen of a graphical user interface usable to display a pie chart according to this invention;
[0037] FIG. 20 shows one exemplary embodiment of a screen of a graphical user interface usable to display multiple pie charts according to this invention;
[0038] FIG. 21 shows one exemplary embodiment of a screen of a graphical user interface usable to display a table of laboratory results according to this invention;
[0039] FIG. 22 shows one exemplary embodiment of a screen of a graphical user interface usable to display medication tables according to this invention;
[0040] FIG. 23 shows one exemplary embodiment of a screen of a graphical user interface usable to display a data entry table for medication according to this invention;
[0041] FIG. 24 shows one exemplary embodiment of a screen of a graphical user interface usable to display an exercise log according to this invention;
[0042] FIG. 25 shows one exemplary embodiment of a screen of a graphical user interface usable to display a blood pressure log according to this invention;
[0043] FIG. 26 shows one exemplary embodiment of a sere-en of a graphical user interface displaying a tabular data summary and patient and healthcare practitioner comments according to this invention;
[0044] FIG. 27 shows one exemplary embodiment of a screen of a graphical user interface usable to enter patient comments into a tabular summary according to this invention;
[0045] FIG. 28 shows one exemplary embodiment of a screen of a graphical user interface displaying a date selection graphic according to this invention;
[0046] FIG. 29 shows one exemplary embodiment of a screen of a graphical user interface displaying educational information according to this invention;
[0047] FIG. 30 shows one exemplary embodiment of a screen of a graphical user interface displaying a particular educational information according to this invention;
[0048] FIG. 31 shows one exemplary embodiment of a screen of a graphical user interface displaying a contacts page according to this invention,
[0049] FIG. 32 shows a second exemplary embodiment of the main patient data screen of the graphical user interface according to this invention for a patient having a chronic kidney illness;
[0050] FIG. 33 shows the main patient data screen of FIG. 30 displaying another educational article according to this invention;
[0051] FIG. 34 shows a second exemplary embodiment of the patient supplied data screen of the graphical user interface according to this invention displaying an automated cycler flow sheet;
[0052] FIG. 35 shows a second exemplary embodiment of the screen of a graphical user interface usable to display linear graphs according to this invention;
[0053] FIG. 36 shows a second exemplary embodiment of the screen of the graphical user interface usable to display a table of laboratory results according to this invention;
[0054] FIG. 37 shows a second exemplary embodiment of the screen of the graphical user interface usable to display medication tables according to this invention;
[0055] FIG. 38 shows a second exemplary embodiment of the screen of the graphical user interface displaying an educational page according to this invention for patients having a chronic kidney illness;
[0056] FIG. 39 shows one exemplary embodiment of a screen of a graphical user interface usable to display recipes available to patients according to this invention;
[0057] FIG. 40 shows the graphical user interface screen of FIG. 34 displaying an educational article on kidney disease;
[0058] FIGS. 41A-B show the graphical user interface of FIG. 34 displaying an educational article about peritoneal dialysis having selectable links according to this invention;
[0059] FIG. 42 shows one exemplary embodiment of a screen of a graphical user interface displaying an abstract of an educational article for patients having a chronic kidney illness according to this invention;
[0060] FIGS. 43 and 44 show various exemplary embodiments of screens of a graphical user interface displaying procedure instructions to a patient;
[0061] FIGS. 45A-45C and 46 A- 46 E show various exemplary embodiments of screens of a graphical user interface usable to display specific procedure instruction and troubleshooting information for performing the procedure illustrated in FIGS. 43 and 44 ;
[0062] FIGS. 47A-47I show one exemplary embodiment of a screen of a graphical user interface usable to display daily routine information for peritoneal dialysis patients according to this invention;
[0063] FIG. 48 shows another exemplary embodiment of a screen of the graphical user interface according to this invention usable to display on-screen contextually relevant messages;
[0064] FIG. 49 shows one exemplary embodiment of a screen of a graphical user interface that enables access to the patient's healthcare practitioners over a distributed network according to this invention;
[0065] FIG. 50 shows one exemplary embodiment of a screen of a graphical user interface usable by a healthcare practitioner to access a patient's healthcare records according to this invention,
[0066] FIGS. 51A and 51B show various exemplary embodiments of a practitioner screen of a graphical user interface usable to display various exemplary embodiments of alerts, messages and reminders according to this invention;
[0067] FIGS. 52 , 54 and 55 show various exemplary embodiments of screens of a graphical user interface displaying medication tables to a practitioner according to this invention;
[0068] FIG. 53 shows one exemplary embodiment of a screen of a graphical user interface displaying insulin pump information to a practitioner according to this invention;
[0069] FIG. 56 shows one exemplary embodiment of a screen of a graphical user interface displaying tabular data summary and healthcare practitioner comments to a patient according to this invention;
[0070] FIG. 57 shows one exemplary embodiment of a screen of a graphical user interface usable to add a new patient or practitioner according to this invention;
[0071] FIG. 58 shows one exemplary embodiment of a screen of a graphical user interface usable to submit practitioner registration information;
[0072] FIG. 59 shows one exemplary embodiment of a screen of a graphical user interface usable to submit patient registration information according to this invention;
[0073] FIGS. 60-62 show various exemplary embodiments of the screens of a graphical user interface usable to submit patient lab data according to this invention;
[0074] FIGS. 63-65 show various exemplary embodiments of screens of a graphical user interface usable to input patient reminder information according to this invention;
[0075] FIG. 66 shows one exemplary embodiment of a main visitor data screen of a graphical user interface according to this invention;
[0076] FIGS. 67A-67G show one exemplary embodiment of a screen of a graphical user interface displaying project description information according to this invention;
[0077] FIG. 68 shows one exemplary embodiment of a patient message list screen of a graphical user interface according to this invention;
[0078] FIG. 69 shows one exemplary embodiment of a patient message list screen of a graphical user interface according to this invention;
[0079] FIG. 70 shows one exemplary embodiment of a screen of a graphical user interface usable to add a message according to this invention;
[0080] FIG. 71 shows one exemplary embodiment of a healthcare practitioner message list screen of a graphical user interface according to this invention;
[0081] FIG. 72 shows one exemplary embodiment of a healthcare practitioner message list window of a graphical user interface according to this invention;
[0082] FIG. 73 shows a first exemplary embodiment of a healthcare practitioner message list screen of a graphical user interface according to this invention after a patient has been selected by a healthcare practitioner, and
[0083] FIG. 74 shows one exemplary embodiment of a healthcare practitioner message list window of a graphical user interface according to this invention after a patient has been selected by a healthcare practitioner.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0084] FIG. 1 shows one exemplary embodiment of a chronic illness management system 100 that is usable to manage one or more chronic illnesses. As shown in FIG. 1 , the chronic illness management system 100 according to this invention includes one or more healthcare practitioner data terminals 130 , one or more patient data terminals 120 , and zero, one or more visitor data terminals 140 , that are connected by a network 110 to a clinic system 200 that implements a virtual clinic. The network 110 may be a local area network (LAN), a wide area network (WAN), the Internet, an intranet, an extranet, or any other known or later-developed type of distributed network 110 usable to connect patients, healthcare practitioners and/or visitors to the clinic system 200 .
[0085] Thus, the chronic illness management system 100 connects patients, healthcare practitioners and/or visitors to the virtual clinic over a distributed network. Access and privileges of the chronic illness management system 100 are determined by a user's status as a patient, a healthcare practitioner, or a visitor. Patient users may provide quantitative clinical data, based on the operation of a medical device 122 , and/or comments to their healthcare practitioner over one of the one or more patient data terminals 120 . The chronic illness management system 100 uses the network 110 to connect patients having one or more chronic illnesses, healthcare practitioners of various occupations, for example, specialized healthcare practitioners. primary care healthcare practitioners, nurses, and the like, and visitors to the clinic system 200 .
[0086] In various exemplary embodiments, each patient data terminal 120 , each healthcare practitioner data terminal 130 , and/or each visitor data terminal 140 can be implemented using standard personal computers, laptop computers, handheld computers, and/or personal digital assistants, or the like, having one or more of a network interface, a data display device, such as a video monitor, one or more input devices, such as a keyboard and/or a mouse, and a network browser software program, or any other known or later-developed hardware elements, any other known or later-developed software components, or any known or later-developed combination of such hardware components and software components that may provide equivalent functionality. Each patient data terminal 120 may also have an input/output interface to which the medical device 122 can be connected to allow clinical data to be directly downloaded from the medical device 122 and sent over the network 110 to the clinic system 200 .
[0087] FIG. 2 shows in greater detail one exemplary embodiment of the clinic system 200 of FIG. 1 . In the exemplary embodiment of the system 200 shown in FIG. 2 , the clinic system 200 shows a network interface 210 , an (optional) firewall 212 , a memory 230 , a controller 220 , a control/data bus 240 and a database 232 that stores at least some of the information described below. The network interface 210 can, in various exemplary embodiments, provide system security by encrypting and transmitting through a secure portion by using, for example, hypertext transfer protocol secure (HTTPS) running over a secure socket layer (SSL) or by any other known or later-developed security mechanism. The optional firewall 212 , if implemented, uses a combination of hardware elements and/or software components that moderates the communication of the clinic system 200 with systems external to the clinic system 200 and vice versa. The optional firewall 212 , if implemented. uses, for example, an external proxy server that decides whether communications are safe to pass through to the clinic system 200 .
[0088] In general, the memory 230 can include one or more of random access memory, read only memory, hard disks, writeable optical disks, flash memory or the like. In general, the controller 220 receives data from and generates instructions to the other components of the clinic system 200 , and reads, writes and processes data. The database 232 stores at least information concerning patients and healthcare practitioners, clinical data received from patients, laboratory test results, information concerning medications that will be or have been prescribed to and/or used by one or more patients, educational information, and general information concerning the chronic illness management system 100 .
[0089] It should he appreciated that the following discussion is generally equally directed to standard windowed graphical user interfaces and graphical user interfaces using web-based implementations, where each graphical user interface “screen” is a distinct web page written in HTML, XML or any other known or later-developed web page authoring language. As a result, in various exemplary embodiments, the selectable icons of the following description are implemented as hypertext links to related web pages or to distinct regions of a current web page. However, it should be appreciated that any other known or later-developed graphical user interface implementation technique could be used to implement the graphical user interface screens and/or graphical user interface elements described herein.
[0090] Thus, it should also be appreciated that this graphical user interface can be implemented as a Windows-based system, rather than as a web-based system. In this case, the graphical user interface screens are distinct portions of the graphical user interface that is accessed by specific Windows events that are associated with particular selectable icons or other interactive elements or widgets. As a result, the selectable icons and other interactive elements of these graphical user interface screens can be implemented as Windows widgets or the like.
[0091] It should also be appreciated that, in the following discussion of the graphical user interfaces and screens according to this invention, selecting a selectable icon or other interactive element can include activating any feature of the graphical user interface that generates a new screen or allows the patient to enter data, for example, by using a drop-down list box, a dialog box, an option button, or the like. An on-screen indicator usable to select a feature of the graphical user interface may be, for example, a mouse pointer, a cursor, or any other known or later-developed on-screen indicator used in conjunction with, for example, a mouse, a touch pad, a touch screen, a light pen, a joystick, a trackball or any other known or later-developed on-screen location input device.
[0092] As shown in FIG. 3 , when a patient or a visitor logs onto the chronic illness management system 100 from one of the data terminals 120 , 130 or 140 via the network 110 , the clinic system 200 presents a graphical user interface screen 300 having a graphic representation of a clinic 304 of the outside of a clinic building. In some exemplary embodiments, this graphic representation of the clinic 304 shows, for example, an entrance door 302 to the clinic, and one of mote of a name of the clinic or the building, reflections of the sky in the clinic windows, surrounding walkways and flowerbeds, and a name of the clinic program to which the patient belongs. This graphic representation of the clinic 304 provides the patient with a feeling that the patient is effectively visiting an actual clinic, which is both familiar and assuring.
[0093] In various exemplary embodiments, the graphic representation of the clinic 304 further elicits a feeling of timeliness by changing aspects of the graphic representation of the clinic 304 to reflect the time of day and time of year when the patient logs onto the system. For example, if the patient logs on during a summer day, the graphic representation of the clinic 304 shown in FIG. 3 shows the clinic during a summer day with blue skies reflected in the clinic windows and blossoming flowerbeds outside the clinic entrance. Other graphic representations of the clinic 304 are automatically displayed on the screen corresponding to the different seasons and time of day. For example, a graphic representation for a winter day may show blue skies reflected in the clinic windows, snow piled on the flowerbeds and ledges of the clinic, and snowflakes drifting down from the sky. The graphic representation of the clinic 304 for both summer and winter nights may, for example, show darkened clinic windows that reflect night skies and stars. Aspects of the graphic representation of the clinic 304 can be altered based on holidays and/or other calendar events.
[0094] The graphic representation of the clinic 304 shown in FIG. 3 is part of a graphical user interface that allows the patient and others to access various screens of the chronic illness management that generally mimic activities that could normally have been pursued during an actual visit by the patient to the clinic. Various clinical data and information elements can also be displayed to the patient using these graphical user interface screens. When the patient selects the entrance door icon 302 of the graphic representation of the clinic 304 shown in FIG. 3 , in various exemplary embodiments, the entrance door icon 302 opens using animation. In any case, a graphical user interface screen 400 , as shown in FIG. 4 , of the graphical user interface is displayed in place of the screen 300 .
[0095] FIG. 4 shows one exemplary embodiment of the graphical user interface screen 400 . The screen 400 includes a graphic representation of a clinic lobby 402 . When used, the animated graphic representation of opening the entrance door icon 302 to enter the clinic lobby 402 invokes the feeling of an actual clinic visit. By mimicking an actual clinic visit, the patient's familiarity with the clinical monitoring program can be enhanced, as can be the patient's compliance with the monitoring program. As shown in FIG. 4 , the graphical representation of the clinic lobby 402 includes, for example, furniture and rugs, a smiling receptionist standing behind a counter, a sign-in clipboard icon 408 located on a counter 407 . a door icon 404 leading to a public access library area, and a bulletin board icon 410 usable to access a bulletin board system. Again, the graphic representation of the clinic lobby 402 shows a scene that the patient would expect to encounter during an actual clinic visit.
[0096] In various exemplary embodiments, when the clipboard icon 408 is initially indicated, such as by hovering the cursor over the clipboard 408 , (or is initially selected), the clipboard icon 408 rises by animation above the counter 407 . This rising of the clipboard icon 408 invites the patient to sign into the clinic, just as the patient would do in an actual clinic visit. In response to the user selecting the raised clipboard icon 408 , a graphical user interface screen 500 , as shown in FIG. 7 , is displayed in place of the graphical user interface screen 400 .
[0097] When the door icon 404 to the public access library area of the clinic lobby 402 of FIG. 4 is selected, the door icon 404 opens by animation to the position shown in FIG. 5 . This open door icon 405 invites not only patients. but other visitors who have accessed the chronic illness management system 100 to access public information about the chronic illness management system 100 .
[0098] The bulletin board 410 of FIG. 4 displays various monthly notice icons 420 that may be characterized by graphic designs corresponding to the respective content of the notice. For example, one type of notice may be a holiday notice that contains a graphic design corresponding to the respective holiday for the current month. For example, as shown in FIG. 6 , a January holiday notice 421 may display a party hat, while the other graphics 422 - 425 for the holiday notices may be displayed during the appropriate month. Other graphic designs may readily correspond to other holidays or events. Selecting a different bulletin board notice icon 412 of the bulletin board 410 shown in FIG. 4 may provide access to educational information on chronic illnesses managed by the clinic system 200 . This information may be provided, for example, by links to other network sites, such as Internet sites or worldwide web sites that provide educational information about particular chronic illnesses. For example, during January, a link to the website of the American Diabetes Association may warn diabetics to watch for freezing of their extremities.
[0099] The bulletin board icon 410 shown in FIG. 4 also displays a news item icon 412 concerning chronic illnesses managed by the clinic system 200 . When the news item icon 412 is selected, the graphical user interface screen 1100 , as shown in FIG. 13 , is displayed in place of the graphical user interface screen 400 .
[0100] As shown in FIG. 7 , the graphical user interface screen 500 includes a graphic representation of a clipboard 502 . The patient enters the patient's name or a username and a password into the clipboard 502 , for example, by using a pair of data entry input boxes 504 and 506 . Data is entered into these data entry boxes 504 and 506 by the patient using the keyboard or other data entry device of the patient's data terminal 120 . Access to other screens of the clinic system 200 , which would otherwise be open to an authorized patient, would be denied to a patient or other person who lacks an authorized password. The patient may change an authorized password by selecting the change password icon or hypertext link 508 shown on the clipboard 502 in FIG. 7 .
[0101] The graphical user interface screen 500 shown in FIG. 7 , and various other data entry screens displayed by the clinic system 200 , frequently show two buttons: a submit button 510 and a reset button 512 . The submit button 510 , when selected, sends the data entered by the user, such as the patients name and password entered into the data entry boxes 504 and 506 to the clinic system 200 . The reset button 512 allows the patient to reset the data in the data entry boxes 504 and 506 when an error is made. Of course, it should be appreciated that the submit and reset functions associated with the submit and reset buttons 510 and 512 , respectively, may also be implemented by enabling the enter and backspace keys of a keyboard. It should also be appreciated that data entry in the various screens of the chronic illness management system 100 described herein is not limited to buttons, but may also include, for example, dropdown list boxes, data entry input boxes, dialog boxes and the like, and/or commercial voice recognition software programs that recognize data entry commands and entered data.
[0102] Once the patient has gained authorized access to the clinic system 200 , the clinic system 200 recognizes that patient's chronic illness from its patient records stored in the database 232 . However, the clinic system 200 may be used to manage more than one chronic illness of a patient. As shown in FIG. 8 , in various exemplary embodiments, when such a patient, for example, a patient suffering from both diabetes and kidney disease, signs into the clinic on the clipboard 502 shown in FIG. 7 , the graphical user interface screen 500 is automatically replaced with the graphical user interface screen 600 , as shown in FIG. 8 . In various exemplary embodiments, the screen 600 includes a graphic representation of an elevator 602 having a control panel 610 . By selecting, for example, the second floor elevator button icon 612 , which is labeled “My Kidney Team”, the patient signals that patient's intention to visit the kidney disease clinic portion of the clinic system 200 . Similarly, by selecting the third floor elevator button icon 614 , labeled “My Diabetes Team”, the patient signals that patient's intention to visit the diabetes clinic portion of the clinic system 200 .
[0103] As shown in FIG. 9 , in various exemplary embodiments, in response to the user indicating or activating the second floor elevator button 612 , such as, for example, by putting the cursor over the second floor elevator button icon 612 , an animation of the elevator door 620 opening onto a graphical representation of the kidney disease clinic 630 is displayed. Once the elevator door 620 is shown in the fully open position and the user selects the second floor elevator button icon 612 , the screen 600 is replaced with the particular exemplary embodiment of a main patient data screen that is appropriate for the kidney clinic portion of the chronic illness management system, i.e., the kidney clinic main patient data screen 3200 , as shown in FIG. 32 . Similarly, in various exemplary embodiments, in response to the user indicating or activating the third floor elevator button 614 , such, for example, by putting the cursor over the elevator button icon 614 , an animation of the elevator door 620 opening onto a graphical representation of the diabetes clinic is displayed. Again, once the elevator door 620 is shown in the fully open position and the user selects the third floor elevator button icon 614 , the screen 600 is replaced with the graphical user interface screen 700 , as shown in FIG. 10 . It should be appreciated that the number of clinics and the number of clinic floors accessed by the elevator 602 will depend upon the number of distinct chronic illnesses managed by the chronic illness management system 100 .
[0104] Alternatively, the animation of the elevator door 620 opening can occur in response to the user selecting one of the elevator floor button icons 612 - 616 . In this case, after the elevator door 620 reaches the fully open state, the screen 600 is immediately replaced with the screen of the graphical user interface that is associated with the selected elevator floor button 612 - 616 .
[0105] The patient suffering from multiple chronic illnesses may also return to the clinic lobby 402 after visiting a particular clinic by selecting the lobby elevator button icon 616 . In response to the user indicating or activating the lobby floor elevator floor button icon 616 , such as. for example, by putting the cursor over the lobby elevator button icon 616 , the elevator door 620 is, in various exemplary embodiments, animated to show the elevator 602 opening onto the graphical representation of the clinic lobby floor. After the elevator door 620 opens onto a graphical depiction of the clinic lobby floor and the user selects the lobby floor elevator button icon 616 , the screen 600 is automatically replaced with the screen 400 shown in FIG. 4 . This graphical representation of elevator movement between floors to reach various clinics again mimics the experience the patient would expect to undergo during an actual clinic visit.
[0106] As shown in FIG. 10 , after an authorized patient signs into the clinic system 200 using the screen 500 , and depending on whether the elevator paradigm underlying the screen 600 is used to select a particular clinic for one of a number of chronic illnesses experienced by the patient, the screen 500 or the screen 600 is replaced with a main patient data screen 700 . In the particular exemplary embodiment shown in FIG. 10 , a patient suffering from diabetes has accessed the main patient data screen 700 . Thus, the particular content of the main patient data screen 700 shown in FIG. 7 is that for a patient suffering from diabetes.
[0107] Of course, it should be appreciated that the particular contents of the main patient data screen 700 will depend on the particular chronic illness that the patient who has accessed the main data screen 700 is suffering from and may also depend upon whether the patient has used the elevator control panel 610 to select from multiple chronic illnesses. However, it should be appreciated that, in various exemplary embodiments of the chronic illness management system 100 according to this invention, the various main patient data screens, such as the screens 700 and 3200 , maintain a consistent look and feel for the various icons, data portions and other elements, other than disease-specific data. between the various chronic illnesses that may be managed using the chronic illness management system 100 .
[0108] In particular, it should be appreciated that the main patient data screen, such as the screens 700 and 3200 , is the initial screen shown to patients after the patients sign into any one of the one or more different disease-specific clinics that may be implemented in the chronic illness management system 100 . In various exemplary embodiments, to maintain the consistent look and feel between such different chronic illness clinics, the main patient data screen 700 includes, for example, a frame 800 and a central display area 710 . To maintain the consistent took and feel of the main patient data screen 700 , the frame 800 and the central display area 710 are maintained in consistent locations, shapes and relative proportions. In various exemplary embodiments; the frame 800 is displayed above and to the left of the central display area 710 . However, it should be appreciated that the frame 800 can be positioned in any desired location within the main patient data screen 700 .
[0109] However, because a consistent look and feel for the main patient data screen is maintained regardless of the particular chronic illness clinic that is being accessed, it is possible that a patient suffering from multiple chronic illnesses could have difficulty remembering which particular chronic illness is currently being accessed. Accordingly, in various exemplary embodiments, to help identify which particular chronic illness clinic is being accessed through the main patient data screen, such as the screens 700 or 3200 , the background 810 of the frame 800 or of a frame 3202 of the screen 3200 , can be color coded based on the particular chronic illness clinic that the user is visiting using the main patient data screen 700 . For example, the background 810 for the diabetes clinic main data screen 700 could be blue, while the background 810 for the frame 3202 of the kidney disease clinic main data screen 3200 could be green. Thus, any graphical user interface screen having a frame 800 having a blue background 810 has been accessed through the diabetes clinic portion of the clinic system 200 and/or is displaying diabetes-related data, clinical information, and/or educational information.
[0110] In various exemplary embodiments, the frame 800 may include, for example, a selectable icon or hypertext link 820 displaying the user's name, a date indicator 822 , a selectable icon or hypertext link 824 that is linked to another screen of the graphical user interface, and a selectable icon or hypertext link 826 that is linked to a website for a sponsor of the clinic system 200 , such as a university that is associated with the virtual clinic. In various exemplary embodiments, the frame 800 may also include, for example, a selectable messages icon or hypertext link 832 , a selectable clinical data icon or hypertext link 834 , a selectable education icon or hypertext link 836 , a selectable contact icon or hypertext link 838 and/or a selectable logout icon or hypertext link 840 . Each of the selectable icons or hypertext links 832 - 840 is usable to change the information displayed in the central display area 710 of the main patient data screen 700 .
[0111] As indicated above, each of the elements 832 - 840 can be a selectable icon or a hypertext link. To simplify the following detailed description, the term icon will be used interchangeably with the terms selectable icon and hypertext link.
[0112] In response to selecting the messages icon 832 of the frame 800 , a messages screen 900 is displayed in the central display area 710 of the main patient data screen 700 . In contrast, selecting the clinical data icon 834 causes various types of clinical information and clinical data to be presented to the patient in the central display area 710 of the main patient data screen 700 using the screens 1500 - 2100 and 6800 . In response to selecting the education icon 836 , the diabetes education screen 2200 shown in FIG. 29 is displayed in the central display area 710 of the main patient data screen 700 .
[0113] Selecting the contact icon 838 causes one of a number of contact screens to be displayed, such as the diabetes contact screen 2400 shown in FIG. 31 or a contact screen for the kidney clinic. It should be appreciated that the particular contact screen accessed using the contact icon 838 will depend on a particular chronic illness clinic that the patient is currently visiting. Finally, selecting the logout icon 840 logs the patient out of the currently selected chronic illness clinic and displays the clinic lobby screen 400 or the elevator screen 600 , depending on whether the patient has one or more chronic illnesses, in place of the main patient data screen 700 .
[0114] As shown in FIG. 10 , in various exemplary embodiments, when the main patient data screen 700 is first displayed during any given session, the messages screen 900 is also automatically displayed in the central display area 710 . The messages screen 900 includes a patient greeting 910 , appropriately addressed and based on the time of day (i.e., “Good Morning,” “Good Afternoon,” or “Good Evening”) followed by the patient's name, a selectable icon or hypertext link 920 to a screen that displays the latest news, a dropdown list 930 that allows the patient to access archived news items on various subjects, and alerts portion 940 , a messages portion 950 and a reminders portion 960 .
[0115] In various exemplary embodiments, the information presented to the patient concerning the alert portions 940 , the messages portion 950 and/or the reminders portion 960 of the messages screen 900 is automatically extracted or derived from the data stored in the relational database 232 when the patient initially accesses the main patient data screen 700 by analyzing the data stored in the relational database 232 in real time. The information presented to the patient in the alerts portion 940 , the messages 950 and/or the reminders portion 960 of the message screen 900 is the type of information that a healthcare practitioner or other healthcare practitioner would emphasize to a patient during an actual clinic visit.
[0116] When the amount of information to be displayed in any one of the alerts portion 940 , the messages portion 950 or the reminders portion 960 , or in total in the messages screen 900 , exceeds the size of the central display area 710 , a vertical and/or horizontal scroll bar (not shown), as is well known in the art, can be implemented to allow the patient to view any information that could not initially be displayed in the central display area 710 . Of course, it should be appreciated that this technique will be usable for all of the following screens that can be displayed in the central display area 710 . Thus, use of scroll bars will not be further described.
[0117] As shown in FIG. 10 , the alerts portion 940 , the messages portion 950 and/or the reminders portion 960 of the messages screen 900 may contain medical terms that have embedded hypertext links or graphical user interface widgets, such as the hypertext link or graphical user interface widget 954 shown in FIG. 10 . These hypertext links or graphical user interface widgets allow the patient to access additional screens, separate windows, and/or windows elements of the graphical user interface that provide information about such medical terms.
[0118] Thus, as shown in FIG. 11 , when the patient selects or hovers over or otherwise indicates the hypertext link or graphical user interface widget associated with such a medical term, such as the graphical user interface widget or hypertext link 954 associated with the medical term “HbAIC” in FIG. 10 , contextually relevant information 1000 may be displayed, for example, in a pop-up dialog box 1000 . The information contained within the pop-up dialog box 1000 defines and/or further explains the medical term, symbol or icon associated with the selected or indicated hypertext link or graphical user interface widget. Alternatively, rather than using the pop-up dialog box 1000 , selecting and/or indicating the hypertext link or graphical user interface widget could result in a glossary screen (not shown) being displayed.
[0119] As shown in FIG. 11 , in various exemplary embodiments that use the pop-up dialog box 1000 , selecting or indicating the graphical user interface widget or hypertext link 954 associated with the medical term “HbAlC” in the messages portion 950 results in the pop-up dialog box 1000 being displayed and containing a contextually relevant message providing a definition for this medical term. Similarly, in various exemplary embodiments, hovering over or indicating, but not selecting, the education icon 836 of FIG. 10 also causes a contextually relevant message (not shown) to be displayed that may further characterize the education icon 836 as “a diabetes educational site”.
[0120] The messages portion 950 can also optionally include a hypertext link or graphical user interface widget (not shown) that allows a patient to provide comments when the patient has entered new clinical data, such as blood glucose values, into the clinic system 200 . In this case, selecting the hypertext link or graphical user interface widget associated with the newly entered clinical data, such as, for a diabetes patient, blood glucose levels, results, in various exemplary embodiments, in a text entry box (not shown) being displayed to the patient. Alternately, in various other exemplary embodiments, this results in the message screen 900 being replaced with a clinical data comments screen (not shown). In either case, in response to selecting the hypertext link or graphical user interface widget associated with the new clinical data, the patient is able to enter comments about the new clinical data from that patient's data terminal 120 ,
[0121] As shown in FIG. 12 , when the patient selects the patient's name icon 820 in the frame 800 , the main patient data screen 700 is replaced with an update patient information screen 1200 . The update patient information screen 1200 may include a number of data entry boxes 1201 - 1206 usable, for example, to update the patient's personal information, such as the patient's name, address, telephone numbers, marital status, employment, and/or e-mail or message address. The update patient information screen 1200 can also include a number of data entry boxes 1210 - 1212 usable to update the patient's medical information, such as the name and/or telephone number of that patient's primary care healthcare practitioner, and/or that patient's allergies. Finally, the update patient information screen 1200 can include a number of data entry boxes 1220 - 1223 usable to update the patient's emergency information such as the name, address, relationship and/or telephone number of that patient's emergency contact.
[0122] As shown in FIG. 13 , in response to the patient selecting the hypertext link or graphical user interface widget 920 , the messages screen 900 displayed in the central data area 710 of the main patient data screen 700 is replaced with a news screen 1100 . The news screen 1100 displays one or more recent news articles that are relevant to the particular chronic illness that the patient was managing at the time the hypertext link or graphical user interface widget 920 was selected. As described above with respect to the messages screen 900 , when the news article displayed in the news screen 1100 exceeds the size of the central display area 710 , the entire news article may be viewed by using vertical and/or horizontal scroll bars (not shown). Using the archives news dropdown list box 930 allows archival news to be selected for display in the news screen 1100 .
[0123] As shown in FIG. 10 , the alerts portion 940 of the messages screen 900 displays information to the patient that is derived from the clinical data supplied, or often, not supplied, by the patient to the clinic system 200 over the patient's data terminal 120 and the network 110 . For a diabetic patient, the information displayed in the alerts portion 940 is derived from an automated, real-time analysis by the clinic system 200 of the measured blood glucose values that the patient has sent to the clinic system 200 and which has been stored in the relational database 232 _ The alerts portion 940 summarizes those events, and activities and/or inactivities, which may be detrimental to the patient.
[0124] Data is analyzed by the clinic system 200 to inform patients, using the alerts portion 940 , about various clinical parameters that have reached an indicated alert level, In the data illustrated in the exemplary embodiment shown in FIG. 10 , the latest HbAlC value is greater than the site/patient configurable value. As a result, the value of the patient's latest HbAlC value is printed in red and an appropriate message is attached and displayed in the alerts portion 940 . Similarly, if the patient's Average Blood Glucose value over the last 2 weeks is greater than the site/patient configurable value, the patient's Average Blood Glucose value is printed in red and an appropriate message is attached and displayed in the alerts portion 940 . If the number of hypoglycemic events and/or hyperglycemic events exceeds the corresponding site/patient configurable value, then the stored clinical data is analyzed to show when these hypoglycemic and/or hyperglycemic events occurred. As shown in FIG. 14 , these hypoglycemic events and/or hyperglycemic can be organized by the day of week in the table portion or tabular chart 1410 and/or by the time of day in a table portion or tabular chart 1412 of an events screen 1400 . Similarly, if more than a site/configurable time period has past since receiving new blood glucose data, then the number of days is printed in red and a message is attached and displayed in the alerts portion 940 .
[0125] Additionally, in the data illustrated in the exemplary embodiment shown in FIG. 10 , data is analyzed to inform a patient about positive results in the patient's data in the messages portion 950 . If the patient's Average Blood Glucose value over the previous two weeks is less than site/patient configurable value, then that value is printed in green, with a smiley face 952 and message attached and displayed in the messages portion 950 . If the patient's latest HbAlC value is less than site/patient configurable value and has decreased by a site/patient configurable amount, then that value is printed in green, with a smiley face 952 and message attached and displayed in the messages portion 950 . Finally, if a patient has sent new blood glucose data without attaching a comment, the patient is prompted to do so at that time by displaying an appropriate message in the messages portion 950 . Of course, it should be appreciated that the particular alerts and messages displayed in the alerts portion 940 and the messages portion 950 will depend on the particular chronic illness the patient is suffering from
[0126] In the exemplary embodiment illustrated by the data shown in FIG. 10 , the clinic system 200 has analyzed the blood glucose values submitted by the patient and has determined from the clinical data and/or other information stored in the relational database 232 that this patient has not reported blood glucose data (BO data) in 696 days. In performing its analysis, the clinic system 200 compares the number of days for which blood glucose values were not reported to a threshold value. When this threshold value is exceeded the clinic system 200 causes an appropriate alert message to be displayed in the alerts portion 940 . The number of days a blood glucose value has not been received may also be emphasized to the patient by color coding the number of days, in this case 696 , displayed in the alerts portion 940 , depending on the urgency and/or importance of the message.
[0127] In the exemplary embodiment illustrated by the data shown in FIG. 10 , the clinic system 200 also summarizes the number of hypoglycemic and hyperglycemic events present in the information and clinical data stored in the relational database 232 . The clinic system 200 causes the generated summary information to be displayed in the alerts portion 940 as well. The clinic system 200 determines these types of events by comparing the clinical data stored in the relational database 232 to one or more threshold values. The threshold values have been entered into the clinic system 200 by a healthcare practitioner via one of the healthcare practitioner data terminals 130 . Each event, or each set of events, is associated with a hypertext link or a graphical user interface widget, as shown in the alerts portion 940 .
[0128] When the patient selects the hypertext link or graphical user interface associated with such an event listed in the alerts portion 940 , the messages screen 900 displayed in the central data portion 710 is replaced with the events screen 1400 shown in FIG. 14 . As shown in FIG. 14 , the events screen 1400 shows various organizations of the events associated with the selected hypertext link or graphical user interface widget. For example, when the hypertext link or graphical user interface widget 942 regarding hypoglycemic and/or hyperglycemic events shown in FIG. 10 is selected, the events screen 1400 shows various hypoglycemic and/or hyperglycemic events associated with that hypertext link or graphical user interface widget organized by day of week in a first tabular chart 1410 and by time of day in a second tabular chart 1412 .
[0129] The information displayed in the messages portion 950 may also be provided by the clinic system 200 . The messages that may be displayed in the messages portion 950 include, for example, that MAX and/or average blood glucose are in target. The real-time analysis by the clinic system 200 of the patient's blood glucose values that are stored in the relational database 232 , when compared to a clinical target range provides information about the number of times the patient's blood glucose values either fall below or exceed the normal range. Based on the number of times the patient's blood glucose values are not normal, the messages displayed in the messages portion may indicate whether the patient is properly managing his or her diabetes. For example, good management of the patient's diabetes may be indicated by animated yellow smiting faces 952 , while poor management may be indicated by blue frowning faces (not shown). A green blood glucose value or clinical test value in a message may indicate a normal value, indicating good clinical management of the diabetes. Messages are the type of information that a clinician is likely to emphasize to a patient during a clinical visit.
[0130] In FIG. 10 , the patient's healthcare practitioners have entered reminders to the patient, for medical tests, exams and visits, into the clinic system 200 , These reminders are stored in the relational database 232 . Data is mined to determine and/or generate reminders of lab tests, clinic visits, etc. for the patient. These reminders are then displayed in the reminders portion 960 . The status of the reminders, such as, whether the patient has properly responded to the reminder, can be color-coded. In various exemplary embodiments, such as that shown in FIG. 10 , a patient is prompted, at a site/patient configurable time prior to the event, to schedule an appointment. For example, the days past due for an appointment to have been scheduled, or a missed appointment, may be emphasized by setting the appearance of some or all of that text string to red. In the exemplary embodiment shown in FIG. 10 , the number of days the appointment is past due is displayed in red.
[0131] Selecting the clinical data icon 834 when accessing the diabetes clinic changes the information displayed in the central display area 710 to one of a set of interlinked clinical data screens 1500 - 2100 and a message list screen 6800 . In particular, in the exemplary embodiments shown in FIG. 15 , the clinical data screen initially displayed upon selecting the clinical data icon 834 is a patient supplied data screen 1500 . However, it should be appreciated that any of the clinical data screens 1500 - 2100 or the messages list screen 6800 could be initially displayed.
[0132] The patient supplied data screen 1500 displays the clinical data that has been submitted to the system by the patient using the medical device 122 , such as, an automated or manual blood glucose meter. For a diabetic patient, the clinical data are the patient's blood glucose values, displayed as a blood sugar log 1510 in the patient supplied data screen 1500 , as shown in FIG. 15 . The blood sugar log 1510 is a chart with summary data. An explanatory legend 1512 is located beneath the chart, as shown in FIG. 15 .
[0133] The patient supplied data screen 1500 also includes a tool bar 1520 that includes a number of icons usable to change the type of graphing used to display the patient supplied data and a tool bar 1501 that includes a number of icons usable to switch between the various clinical data screens 1500 - 2100 and 6800 . It should be appreciated that the patient supplied data screen 1500 can also be accessed through the icon 1503 of the toolbar 1501 .
[0134] The blood sugar log 1510 displays blood glucose (BG) values by date and time of day in the chart. A single row of the chart may display the date, blood glucose values at specific time intervals during the day, the number of blood glucose values obtained in a day (# Readings), and the average value of the blood glucose readings for the day (Avg. Reading). At the bottom of the blood sugar log 1510 , the average values of blood glucose for a specific daily time interval and the average number of readings per time frame (not shown) may be displayed. Additional rows at the bottom of the chart may display the number of hypoglycemic events and hyperglycemic events (not shown) that occur in a specific daily time interval for the displayed dates.
[0135] In the blood sugar log 1510 , a blood glucose value having an associated graphical user interface widget or hypertext link may indicate that more than one blood glucose reading was taken during a time interval. When multiple blood glucose readings occur within a time interval, only the first blood glucose value is displayed in the chart. However, when the graphical user interface widget or hypertext link associated with such a blood glucose value is selected, an on-screen contextual message (not shown) displays all the blood glucose values submitted during that interval.
[0136] Beneath the blood sugar log 1510 , the average blood glucose value for all time intervals over the displayed dates is shown, along with a statistical standard deviation of all the blood glucose values and the range of blood glucose values, indicating maximum and minimum blood glucose values (not shown). Additionally, the legend 1512 beneath the blood sugar log 1510 explains the color coding of the blood glucose values in the chart, which may represent hypoglycemic values in blue, hyperglycemic values in red, and normal blood glucose values in green Hypoglycemic and hyperglycemic values may, alternatively, be displayed with an associated minus sign or plus sign, respectively.
[0137] In particular, in various exemplary embodiments of the systems and methods according to this invention, the values in the log book are color coded and/or are preceded by a + sign or a − sign, depending on their value. If the values in the log book arc greater than a site/patient configurable value, then the values are displayed in red and preceded by a +. If the values in the log book are less than a site/patient configurable value, the values are displayed in blue and preceded by a − If the values in the log book are greater than a site/patient minimum configurable value and less than a site/patient maximum configurable value, the values are displayed in green. Additionally, if multiple readings for a given day and a given time slot are available, the first reading for that day and time slot is displayed, but the other values are available by moving the mouse over the first reading. In response, a pop-up window is displayed that includes some or all of the readings for that day and time slot.
[0138] By selecting the date hypertext link or graphical user interface widget 1514 in the upper left corner of the blood sugar log 1510 of FIG. 15 , the screen changes to that of a date interval selection screen or window 1570 , as shown in FIG. 16 . In the date interval selection screen or window 1570 , the patient may select the dates for which the blood sugar log 1510 is to display blood glucose values. The patient may select either the last 14 days entered in the blood sugar log book by an option button 1572 or a “Start Date/End Date” option by selecting a second option button 1574 . If the “Start Date/End Date” option is selected, the patient may enter the start and end dates into, for example, standard data entry input boxes 1576 , as shown in FIG. 16 .
[0139] The graphing icons in the toolbar 1520 located on the clinical data screen 1500 may change the presentation of the blood sugar log 1510 . For example, if the patient selects the animated line chart icon 1522 , the tabular blood sugar log 1510 is replaced with a linearly plotted graph 1530 , as shown in FIG. 17 . This linearly plotted graph 1530 plots blood glucose values against time during the date interval that is displayed above the graph. Similarly, selecting the animated “Histograms” icon 1524 displays the data contained in the blood sugar log 1510 as two histograms 1540 and 1542 , shown in FIG. 18 . The first histogram 1540 plots blood glucose values against days of the week, and the second histogram 1542 plots blood glucose values against the daily time intervals.
[0140] These different data presentations may help the patient to understand any daily or weekly patterns of changes in blood glucose values. Such patterns would usually be discussed in an actual clinic visit to explore activities surrounding the time during which such changes of blood glucose values occur, so as to avoid possible hypoglycemic or hyperglycemic events
[0141] When the pie chart icon 1526 of FIG. 15 is selected, the data contained in the blood sugar log 1510 is shown as percentages of blood glucose readings above, below and within the target range of clinically desired blood glucose values in a pie chart 1550 , as shown in FIG. 19 . Sectors of the pie chart may also be color coded to reflect the percentage of blood glucose readings above, below and within a clinical target range as explained in the legend 1552 . For example, a sector of the pie indicating the percentage of blood glucose readings that are above the target blood glucose range may be colored red, while those that are within the target range are colored green and those below the target range are colored blue. Alternatively, various shadings or graphics may be used to distinguish between the pie chart sectors.
[0142] Selecting the multiple pie chart icon 1528 results in a pie chart 1560 - 1564 for each specific daily interval of the blood sugar log 1510 , as shown in FIG. 20 . Each pie chart 1560 - 1564 indicates the percentage of blood glucose readings that were above, below or within the target blood glucose range for a particular time interval. Again, sectors of each pie may be color coded to reflect the percentage of blood glucose readings above, below and within a clinical target range as explained in the color-coded legend 1566 , or indicated by pluses or minuses (not shown). When no blood glucose readings correspond to a particular daily time interval, a message 1568 , for example, “No data for this timeslot”, may be presented, as shown in FIG. 20 . The line charts 1530 shown in FIG. 17 , the histograms 1540 and 1542 shown in FIG. 18 , and the pie charts shown in FIGS. 19 and 20 are tied to the data range and the data displayed in the blood sugar log 1510 . If the date range is changed in the log book, then the date range on the graphs also changes.
[0143] Selecting the lab results icon 1502 of the toolbar 1501 changes the displayed one of the clinical data screens 1500 - 2100 or 6800 to the laboratory test results screen 1600 . FIG. 21 shows one exemplary set of such laboratory test results displayed in the laboratory test results screen 1600 . The laboratory test results screen 1600 presents laboratory test results of for example HbAIC, cholesterol, HDL, LDL, triglycerides, and urine microalbumin in a table 1610 , indicating the laboratory test and the month the laboratory test was taken. When any of the laboratory tests having an associated hypertext link or graphical user interface widget is selected, an on-screen contextual message (not shown) may appear to explain what the laboratory test measures, its clinical significance and the acceptable clinical range of test values.
[0144] In FIG. 21 , the patient has HbA1C test results that fall within the acceptable clinical range for the month of May. In this case, a simple comparison of the laboratory results with acceptable clinical values stored in the relational database 232 by the clinic system 200 is performed in real-time to determine whether the value is acceptable. For example, in various exemplary embodiments, if the HbAlC value is less than a site/patient configurable value, then a text message and/or an audio message is presented to the user in a message portion 1620 . As shown in FIG. 21 , the illustrated test results are below a site/patient configurable value. As a result, because the test results are acceptable, the clinic system may present in the message portion 1620 a congratulatory comment from the patient's healthcare practitioner, such as “Great Ale this month-Keep it up”, possibly accompanied by the sound of applause. This message and sound of applause provide motivation to the patient, when the patient has done well in managing his or her blood glucose values and are meant to reflect the feedback a patient would normally receive during a clinic visit from his or her healthcare practitioner.
[0145] Selecting the medication icon 1504 of the toolbar 1501 changes the displayed one of the clinical data screens 1500 - 2100 or 6800 to a medications screen 1700 . The medications screen 1700 shows the medications used by the chronic illness patient. In the particular exemplary embodiment shown in FIG. 22 , the medications screen 1700 is one that is appropriate for a diabetic patient. It should be appreciated that the contents of the medications screen will change depending on the particular chronic illness, as illustrated by the second exemplary embodiment of the medications screen 3700 shown in FIG. 37 .
[0146] In the prescription portion 1710 , the date and time of the current prescription for insulin, which has been prescribed by clinic healthcare practitioners, may be displayed. In the prescription portion 1710 of the medication screen 1700 displayed for a diabetic patient, an insulin medication table 1712 may indicate that both long and short acting insulin are currently prescribed for the patient. display the common or trade names of the prescribed insulin, and the dosage values and time of day that the prescribed type of insulin is to be taken. Previous prescription orders for insulin may be viewed by selecting the previous prescription hypertext link or graphical user interface widget 1714 . The previous prescription order date is then displayed above the insulin medication table 1712 , which now contains information about the previous prescription order. After reviewing the previous order, the patient may advance the prescription order to the current prescription date and order by selecting a next prescription graphical user interface widget or hypertext link (not shown), which will be displayed if the currently displayed prescription information is not that for the latest insulin prescription.
[0147] For diabetic patients who have an insulin pump, the insulin prescription information may be presented in a separate table (not shown) that includes, for example, the insulin pump prescription showing time versus basal rate, bolus information by meal including grams of carbohydrate, bolus size, insulin to carbohydrate ratio, prescribed supplemental insulin and information explaining how insulin converts various foods to carbohydrates.
[0148] In an oral medication portion 1720 of the medication screen 1700 , the date of the current prescription of oral prescription drugs other than insulin, which has been prescribed by clinic healthcare practitioners, and an oral medication table 1722 is shown that may indicate the type of oral medication, its name, the dosage and number of tablets per dose, and the frequency with which the medication is to be taken. As described above, previous oral medication prescription orders and information concerning the previous prescription orders may be reviewed by selecting a previous prescription hypertext link or graphical user interface widget 1724 located above the oral medication table. Similarly, after reviewing a previous oral medication prescription order, selecting a next prescription hypertext link or graphical user interface widget (not shown) advances the oral medication prescription date and prescription order.
[0149] In another medication portion 1730 of the medications screen 1700 , non-prescription medications and other prescription medications, prescribed by a non-clinic healthcare practitioner, may be displayed. These other medications are entered into a displayed other medication table 1732 by the patient when he or she selects the add other medication icon 1740 . Selecting the add other medication icon 1740 changes the medications screen 1700 to the add medications screen 1800 shown in FIG. 23 . As shown in FIG. 23 , the add medications screen 1800 includes a data entry table 1810 comprising a number of data entry input boxes 1812 and drop down list boxes 1814 , in which the patient enters the information about other medications. The patient enters into the appropriate data entry input box 1812 via the patient data terminal 120 , the name of the medication, when it was taken, its dosage, and the purpose of the medication. The frequency with which the medication is taken may be entered by accessing one of the drop list boxes 1814 that list once, twice and three times per day, or the like.
[0150] Information concerning the various medications taken by the patient may be communicated to other computerized clinical systems that analyze the information for possible adverse drug interactions. If such a system discovers a possible adverse drug interaction, this information may then be communicated to the clinical management system for chronic illnesses for inclusion in, for example, an alert displayed in the alerts portion 940 . Alternatively, such information may be sent to a clinic healthcare practitioner, who in turn informs the patient.
[0151] Selecting the animated exercise log icon 1505 changes the displayed one of the clinical data screens 1500 - 2100 or 6800 to an exercise data screen 1900 . The exercise data screen 1900 includes an exercise log 1910 , as shown in FIG. 24 , and an exercise event entry portion 1920 . The exercise event entry portion includes a number of drop down list boxes 1922 - 1926 in which the patient may enter the date, type of exercise, and duration of exercise, and a data entry input box 1928 for entering the patient's comments. Entering the date of a log entry may be facilitated by a set of standard drop down list box 1922 that allows the patient to select a particular month, date, and year. Similarly, a type of exercise drop down list box 1924 may provide for the selection of, for example, biking, jogging or running, swimming, walking or hiking, golfing, arm chair exercising, other sports, gardening, housework, and other activities. The duration of an exercise may be entered by a drop down list box 1926 that provides for the selection of 15, 30, 45 and 60 minutes or an “other” time interval. The data entry input box 1924 permits the patient to enter the patient's comments, via the patient's data terminal 120 , which the patient feels will be relevant to the healthcare practitioner or may more fully describe an exercise activity or its duration. Comments from a healthcare practitioner may also be displayed in the exercise data screen 1900 , indicating to the patient that the healthcare practitioner is reviewing and evaluating the level of the patient's physical activity.
[0152] Selecting the blood pressure icon 1506 of the toolbar 1501 changes the displayed one of the clinical data screens 1500 - 2100 or 6800 to a blood pressure data screen 2000 . The blood pressure data screen 2000 includes a patient blood pressure log 2010 , as shown in FIG. 25 . The blood pressure log 2010 is a table that displays blood pressure values by date, that are obtained from an automated or manual medical device 122 that the patient may connect to the patient's data terminal 120 and/or directly to the network 110 . The blood pressure log 2010 allows for patient-entered comments. The blood pressure data screen 2000 also includes a manual entry portion 2020 that includes a number of data entry boxes 2022 - 2028 . The patient may enter the date using drop down list boxes 2022 , while systolic and diastolic blood pressures and comments may be entered into, for example, by the data entry input boxes 2024 , 2026 and 2028 , respectively. Comments (not shown) from the healthcare practitioner about the patient's blood pressure may be displayed in the blood pressure data screen 2000 . It should be appreciated that, if the clinic system 200 is able to accept data from an electronic blood pressure device as the medical device 122 , the manual entry portion 2020 may be omitted.
[0153] Selecting the data summary and healthcare practitioner comments icon 1507 changes the displayed one of the clinical data screens 1500 - 2100 or 6800 to the summary screen 2100 . The summary screen 2100 includes a tabular summary 2110 , as shown in FIG. 26 . In FIG. 26 , the tabular summary 2110 presents by date, for example, the average blood glucose value, the standard deviation of the blood glucose values, the number of hypoglycemic and hyperglycemic events, the percentage of blood glucose readings within the desired target range, the average number of blood glucose readings per day, and the number of days for which the clinical data is summarized. When reviewing the tabular summary 2110 of FIG. 26 , the patient may enter comments regarding his or her latest blood glucose values, for example, by a standard data entry box 2120 as shown in FIG. 27 , to which the healthcare practitioner may reply.
[0154] By selecting the date icon 2112 in the upper left corner of the tabular summary 2110 of FIG. 26 , a data selection screen or window 2800 is displayed, as shown in FIG. 28 . The data selection screen or window 2800 shows two options, a “Last 30-Day Summary” option button 2810 or a “Start Date/End Date” second option button 2820 . A “Cancel” button 2840 may cancel the dates' selection screen and return the patient to the summary screen 2100 shown in FIG. 26 .
[0155] Selecting the patient message list icon 1508 of the toolbar 1501 changes the displayed one of the clinical data screens 1500 - 2100 displayed in the central data area 710 to the patient message list screen shown 6800 in FIG. 68 . The patient is presented with a list of messages sent by the patient's healthcare practitioner or by the patient, as shown in FIG. 68 . Information, such as the date a message was sent. to whom the message was sent, who sent the message, and the subject/title of the message may be presented. In various exemplary embodiment, all unread messages in the list are preceded by a red asterisk.
[0156] When the patient selects one of the underlined subject/titles, the clinical management system retrieves the selected message for the patient, as shown in FIG. 69 . A message list screen 6900 appears with information such as the date the message was sent, to whom the message is addressed, who sent the message, the subject/title of the message and the message itself. If the entire message does not fit within the message list screen 6900 horizontal and/or vertical scroll bars are presented for the patient to scroll through the message (not shown). At the end of the message there is a reply button 6910 and a close button 6920 . When selected, the reply button 6910 allows the patient to send a response message to whomever sent the message (not shown). The close button 6920 allows the patient to exit the message list screen 6900 and return the patient to the patient message list screen 6800 of FIG. 68 (not shown). The patient may also exit from the message list screen 6900 by selecting the standard window exit icon (not shown) in the top right hand corner of the message list screen 6900 to return to the patient message list screen 6800 .
[0157] The patient may also create and add a new message to the messages displayed in the patient message list screen 6800 . The patient selects a “Select a CareTeam Member” drop down list box 6810 . The “Select a CareTeam Member” drop down list box 6810 provides a list of the healthcare practitioners in the chronic illness management system 100 . The patient then selects the healthcare practitioner the patient wishes to address the message to (not shown). The patient may also provide a subject/title for the message, but this is not required. The patient does this by simply typing in the subject/title in the “Subject” data entry box 6820 in FIG. 68 .
[0158] If the patient decides to discard the message, has made an error, or wants to change to whom the message is addressed to and/or the subject/title of the message, the patient can select the reset button 6830 . When selected, the reset button 6830 clears to whom the message is addressed to and clears the “Subject” data entry box 6820 The function of the reset button 6830 can also be accomplished by selecting a different individual from the “Select a CareTeam Member” drop down list box 6810 for whom the message is addressed and by backspacing over the incorrect data entry and then typing the correct data in the “Subject” data entry box 6820 .
[0159] After the patient has selected the healthcare practitioner to whom the message is addressed and typed a subject/title for the message (optional), the patient selects the “Add Message” button 6840 . When the patient selects the “Add Message” button 6840 , the patient message list screen changes to the add message screen shown in FIG. 70 . The add a message screen 7000 displays the patient's name as who the message is from, the name of the healthcare practitioner to whom the message is addressed and the subject/title, if provided by the patient. Additionally, there is a message data entry box 7010 , a submit button 7020 , a reset button 7030 , and a cancel button 7040 . The patient then enters his or her message into the message data entry box 7010 by using the keyboard or some other data entry device. Once finished, the patient selects the submit button 7020 to send the message. If the patient is unsatisfied with the inputted message and wishes to discard all of its contents, the patient simply selects the reset button 7030 or backspaces over the undesired portions of the message. However, if the patient wishes to disregard sending a message all together, the patient can select the cancel button 7040 . This returns the patient to the patient message list screen 6800 of FIG. 68 .
[0160] When a diabetic patient selects the education icon 836 of the main patient data screen 700 shown in FIG. 10 or included in any other screen having a blue color-coded frame 800 , the screen displayed in the central display area 710 changes to a diabetes education screen 2200 , as shown in FIG. 29 . The diabetes education screen 2200 includes a number of icons 2210 - 2250 that cause screens providing more detailed information on a particular subject to be displayed. The patient may then select one of the icons 2210 - 2250 , for example, the icon 2210 labeled “What Is Diabetes?”. In response, as shown in FIG. 30 , a second education screen 2300 for the selected topic will be displayed in the central display area 710 .
[0161] The displayed educational topics may include, for example, hypertext links or graphical user interface widgets associated with various words or phrases 2310 , or Web sites 2320 , as shown in FIG. 30 . Selecting such a word or phrase 2310 may result in an on-screen contextually relevant message being displayed that explains or identifies the selected word or phrase. Selecting such a Web site 2320 causes the system to access the associated Web site. Upon leaving the accessed Web site, the patient returns to the displayed educational topic.
[0162] When a diabetic patient selects the contacts icon 838 of the main patient data screen 700 shown in FIG. 10 or included in any other screen having a blue color-coded frame 800 , the screen displayed in the central data area 710 changes to a healthcare practitioner contact screen 2400 . The healthcare practitioner contact screen 2400 includes a graphic and pictorial representation of the clinic's diabetes treatment and monitoring team, as shown in FIG. 31 . A hypertext link or graphical user interface widget 2410 - 2440 is associated with each team member. An email access icon 24122442 is also associated with each team member. If the patient selects the hypertext link or graphical user interface widget 2410 - 2440 of a team member, a short biographical sketch (not shown) of the team member is displayed in a separate window or a separate screen. This biographical sketch helps to familiarize the patient with the clinicians handling the patient's case. If the email access icon 2412 - 2462 is selected, a dialog box containing the corresponding email or message address of the selected team member where that team member can be reached is displayed. if the patient selects the Support Group Message icon (not shown), a dialogue box (not shown) containing the support group's e-mail or message address where the patient may chat with others having the same chronic illness. By selecting the Technical Support Email icon 2462 , the screen may show a dialogue box (not shown) containing the technical support group's e-mail or message address to assist the patient with technical problems associated with communicating with the system and using it properly.
[0163] It should be appreciated that the screens shown in FIGS. 29-31 are the diabetes education screens 2200 and 2300 and the contact screen 2400 as displayed to a healthcare practitioner. The various icons used when displaying these screens to the healthcare practitioner are described in greater detail below with respect to FIG. 50 . That is, the diabetes education screen 2200 and 2300 and the contact screen 2400 display the same information in the central data area 710 to both patients and to healthcare practitioners. The only significant difference when displaying these screens is that the particular tool bar icons displayed in the frame 800 depends on whether these screen are being displayed to a health care practitioners, as shown in FIGS. 29-31 , or to a patient. In that later case, the frame 800 shown in FIGS. 10-28 would be displayed.
[0164] When an authorized kidney disease patient signs on to the clinic system 200 using the clipboard of FIG. 7 , the screen changes to show the kidney main patient data screen 3200 , shown in FIG. 32 , that is appropriate for a patient to manage the patient's kidney disease. The kidney main patient data screen 3200 includes a frame 3202 with upper and left-side borders, and a central display area 3210 , as shown in FIG. 32 . The background 810 of the upper and left-side borders of the frame 3202 of the main patient data screen 3200 may be colored green to signify a kidney disease patient. The background 810 of the upper border of the frame 3202 includes the underlined patient's name 3220 , the date of birth 3222 , an icon 3224 linked to another screen of the graphical user interface and a selectable icon or hypertext link 3226 linked to, for example, a Web site for the associated with the clinic. Selecting the underlined patient's name 3220 changes the screen to the “Patient Information Update” screen, as discussed above and shown in FIG. 12 . The left border of the frame 3202 may include, for example, icons for “messages” 3232 , “clinical data” 3234 . “education” 3236 , and “contact” 3238 that change the information displayed in the central display area 3210 and a “logout” 3239 icon that accesses the screen for the clinic lobby 400 . Among the icons in the left border of the frame 3202 , only the “education” 3236 icon has changed its appearance from that of the frame 800 shown in FIG. 10 , showing, instead, a pair of kidneys. By selecting the “education” 3236 icon for the kidney patient, an on-screen contextually relevant message may read “dialysis education site”.
[0165] The initial screen presented to the kidney disease patient upon entering the kidney disease clinic is the main patient data screen 3200 with “ALERTS:” 3250 , “MESSAGES:” (not shown) and “REMINDERS:” (not shown) displayed in the central display area 3210 of FIG. 32 . In FIG. 32 , the underlined “What's New?” 3242 and the drop down list box 3244 labeled “Kidney Disease News Archive” are connected to information stored in the relational database 232 of the clinic system 200 concerning kidney disease. For example, selecting “What's New?” 3242 displays the latest news concerning kidney disease and peritoneal dialysis, as shown in FIG. 33 . If the amount of information in the news of FIG. 33 exceeds the size of the central display area 3210 , a vertical and/or horizontal scroll bar located at the right border of the screen (not shown) allows the patient to view the entire news
[0166] In FIG. 32 , the information concerning “ALERTS:” 3250 derives from the clinic system's 200 analysis of quantitative clinical data submitted by the patient using a medical device 122 for at-home peritoneal dialysis, blood pressure and weight measures submitted by the patient, and laboratory test results entered into the clinic system 200 by the patient's healthcare practitioner. The information presented to the patient concerning “ALERTS:” 3250 , “MESSAGES:” and “REMINDERS:” is automatically analyzed in real-time by the clinic system 200 from data stored in the relational database 232 when the patient initially accesses the main patient data screen shown in FIG. 32 . The “ALERTS:” 3250 summarize those events and activities, which may be detrimental to the patient and may include, for example, the date of the last PD, that is, peritoneal dialysis data received, weight gain or loss, changes in blood pressure, and clinical laboratory results including creatinine, potassium, albumin, glucose and phosphate levels, and Kt/V, that is, a measure of the quantity of dialysis delivered. In FIG. 32 , for example, the system has determined that the patient has not submitted PD data, that is, peritoneal dialysis data, for 26 days. The “ALERTS:” 3250 may also emphasize the number of days a peritoneal dialysis datum has not been received by using a red color for the number, corresponding to the color of “ALERTS:” 3250 . Additionally, by selecting underlined laboratory tests or medical terms in “ALERTS:” 3250 , an on-screen contextually relevant message (not shown) may be displayed to further explain the laboratory test or medical term.
[0167] The information concerning “MESSAGES:” for a kidney disease patient in the main patient data screen 3200 may include, for example, that Kt/V or other laboratory test values are in a clinically acceptable range, thus, indicating good management of the kidney disease by the patient. Good and poor management of the patient's kidney disease may be indicated to the patient by various messages, including animated smiling or frowning faces (not shown) and accompanying sounds.
[0168] The information concerning “REMINDERS:” for a kidney disease patient in the main patient data screen of 3200 may include reminders entered into the clinic system 200 and stored in the relational database 232 by the patient's healthcare practitioners about upcoming medical visits, medical exams and laboratory tests, and health care tips.
[0169] Selecting the “clinical data” icon 3234 of FIG. 32 or any other patient screen having a green ft − ante, changes the information displayed to that of FIG. 34 , showing a peritoneal dialysis prescription 3404 and the clinical data submitted by the patient to the system, that is, the “Automated Cycler Flow Sheet” 3410 . The “Lab Results” icon 3430 and the “Medication” icon 3434 located above the current peritoneal dialysis prescription table 3404 changes the type of information displayed in the central display area 3405 of FIG. 34 . The “Automated Cycler Flow Sheet” 3432 icon of all patient screens having the green frame displays the “Automated Cycler Flow Sheet” 3410 of FIG. 34 . In FIG. 34 , the current peritoneal dialysis prescription shows the date and time of the prescription above a peritoneal dialysis prescription table 3404 including prescription information relating to, for example, therapy time, dwell time, number of cycles, total volume, fill volume, and Last fill volume. The clinical data of the “Automated Cycler Flow Sheet” 3410 are the date and time of the peritoneal dialysis, the percentage concentrations of the dextrose solutions used, the volume of initial drain, the volume of total UF, that is ultrafiltrate, blood pressure, and body weight, as shown in FIG. 34 .
[0170] Selecting any of the icons 3420 located above the Total UF, BP or WT columns of the “Automated Cycler Flow Sheet” of FIG. 34 changes the presentation of the clinical data of the column to a linear graph of that column's variable versus the Automated Cycler Flow Sheet's time period. For example, FIG. 35 shows, respectively, the changes in Total Ultrafiltrate, Blood Pressure and Weight over the time period of the Automated Cycler Flow Sheet as linearly plotted graphs.
[0171] Selecting the “Lab Results” icon 3430 of FIG. 34 or any other patient screen having a green frame 3202 changes the type of clinical data displayed to that of laboratory test results, as shown in FIG. 36 . FIG. 36 may present twelve dates on which laboratory test results may be displayed in a table 3610 , with rows corresponding to a particular type of laboratory test and columns corresponding to a test date_ The clinic system 200 may display more than twelve test dates with additional table displays. The laboratory test results displayed may include, but are not limited to, for example, Kt/V, albumin, calcium, creatirune, ferritin, glucose, HGB×3 (Hemoglobin times 3), iron, phosphate, potassium, PT1 − 1 (parathyroid hormone), TIBC (total iron binding capacity), TSH (thyroid stimulation hormone), T3, T4, T7 (thyroid studies), cholesterol, HDL (high density lipids), LDL (low density lipids), triglycerides, HBSAG, HBSAB (hepatitis B surface antigens), 1-{EPCAP (hepatitis C surface antigen) and Hb I AC (hemoglobin A I C)
[0172] When any of the laboratory tests of FIG. 34 is selected, an on-screen contextual message (not shown) may appear to explain what the laboratory test measures, its clinical significance to managing the illness and the acceptable range of clinical test values. When laboratory test results indicate that the patient is managing his or her illness well, the clinic system 200 may present a congratulatory message above the table 3610 (not shown). Laboratory test results may be color coded to represent values above, below and within acceptable clinical ranges. For example. red values may represent high results, blue values may represent low results and green values may indicate those within a clinically acceptable range. Alternatively, pluses and minuses may indicate high and low values, respectively.
[0173] Selecting the “Medication” icon 3434 of FIG. 34 or of any other patient screen having a green frame 3202 changes the type of clinical data displayed to that of a “Medications” table 3710 and an “Other Medications” table 3720 , as shown in FIG. 37 . The medications prescribed by the clinic healthcare practitioners are entered into a “Medications” table 3710 for review by the healthcare practitioner and patient. The “Medications” table 3710 may include, for example, the medication name, its dosage, its units, its frequency taken, its route of administration, the prescription start and stop dates, and instructions to the patient.
[0174] The “Other Medications” table 3720 of FIG. 37 includes information about non-prescription medications and other prescription medications, prescribed by non-clinic healthcare practitioners for the patient Thus, the “Other Medications” table 3720 of FIG. 37 provides the patient with a mechanism to enter outside medications the patient may be taking that the healthcare practitioner may not know about. This information is entered into the “Other Medications” table 3720 by the patient when he or she selects the “Add other medication” 3735 icon in the upper right corner of FIG. 37 . The other medications arc added to the table by the data entry tables discussed above in relation to the diabetic patient, as shown in FIG. 23 .
[0175] When a kidney disease patient selects the “education” icon 3236 of FIG. 32 or any other patient screen having a green frame, the upper border of the frame 3202 displays Pager and Clinic telephone numbers, while the central display area 3210 displays the main education page for kidney patients, as shown in FIG. 38 . In the main education page of FIG. 38 , the patient may select among the three underlined educational topics for display: “Kidney Disease and YOU”; “PD-Doing It Right!, Plus: Problems and What YOU should know”; and “Daily Life, Food, Fluids, Meds and FUN”. The main education page of FIG. 38 may also display a “PD News” 3802 icon that when selected displays the latest news about kidney disease and/or peritoneal dialysis. A drop down list box 3804 , labeled “Kidney Disease News Archive”, may allow patients to access archival articles stored in the relational database 232 of the clinic system 200 for display. Additionally, the central display area may display a “Recipes” icon 3806 that when selected displays a current recipe. A drop down list box 3808 , labeled “Recipes”, may allow patients to access other recipes for display in the central display area, as shown in FIG. 39 .
[0176] Selecting the underlined topic of “Kidney Disease and YOU” in FIG. 38 changes the screen to that shown in FIG. 40 . Selecting an underlined word or phrase in the educational article of FIG. 40 may provide an on-screen contextually relevant message (not shown) that defines the word or phrase. By selecting the underlined, quoted article, “ How the Kidney Works ” of FIG. 40 , the system accesses a link to a Web site, for example, nephron.com, that explains the workings of the kidney to the patient. Selecting the underlined phrase “Return to Main Education Page” allows the patient to return to the display of FIG. 38 .
[0177] Selecting the underlined topic of “PD Doing It!, Plus: Problems and What YOU should know” in FIG. 38 changes the information displayed in the central display area to that shown in FIGS. 41A and 41B . Selecting an underlined word or phrase in the educational article shown in FIGS. 41 A and 4 IB may provide an on-screen contextually relevant message (not shown) that defines the word or phrase. When other underlined sentences, such as, “Washing AND drying your hands—read about why it's so important here”, of FIG. 41A arc selected, an abstract of the article, “Washing AND drying your hands—read about why it's so important here”, may be displayed, as shown in FIG. 42 .
[0178] The section “PD INFORMATION” of FIG. 41A , entitled “How to do a SAFE EXCHANGE”, may contain a drop down list box 4105 , labeled “Your Unopened Dialysate Bag is”, that provides a checklist 4310 for a patient to follow when checking his or her unopened dialysate bag to assure proper dialysis technique, as shown in FIG. 43 . Similarly, selecting the drop down list box 4110 , labeled “Your area is”, provides a checklist 4410 for the area the patient selects for his or her peritoneal dialysis, as shown in FIG. 44 .
[0179] The section of “PD INFORMATION” of FIG. 41A , entitled “3 Steps to a SAFE Exchange”, shows three underlined terms, that is, “DRAIN” 4120 , 'PILL″ 4122 and “DWELL” 4124 in a horizontal row. Selecting an underlined term changes the screen to show the information concerning the selected underlined term, as shown for “DRAIN” 4120 , “MU” 4122 and “DWELL” 4124 , in FIGS. 45A-45C , respectively. After reading any of the “3 Steps to a SAFE Exchange” in FIGS. 45A-45C , the patient may return to section entitled “3 Steps to a SAFE Exchange” of FIG. 41A by selecting the phrase, “Click here to dose window”.
[0180] The section of “PD INFORMATION” of FIG. 41B , entitled “Problem List”, shows five underlined phrases, that is, “Cloudy Bag” 4150 , “Unclear but not Cloudy Bag” 4152 , “Leaking Equipment” 4154 , “Cramps” 4156 and “Exit Site Infection” 4158 in a horizontal row. Selecting an underlined phrase changes the screen to show the information concerning the underlined phrase, as shown for “Cloudy Bag” 4150 , “Unclear but not Cloudy Bag” 4152 , “Leaking Equipment” 4154 , “Cramps” 4156 , and “Exit Site Infection” 4158 , in FIGS. 46A-46E , respectively. After reading about any of the problems of peritoneal dialysis, the patient may return to the section entitled “Problem List” of FIG. 4113 by selecting the phrase, “Click here to close window”.
[0181] Selecting the underlined topic of “Daily Life, Food, Fluids, Meds and FUN” of FIG. 38 changes the information displayed in the central display area to that shown in FIGS. 47A-471 . The underlined topics presented under the “Daily Routines” of FIG. 47A may include but are not limited to “Fluids”, “What you eat”. “Your weight”, “Blood Pressure”, “Medications”, “Eating Out”, “Exercise”, “Travel”, “Socializing”, and “Learn More”. In FIG. 47A , selecting any of the underlined topics listed presents an on-screen contextually relevant message between the two columns of under lined topics. For example, FIG. 48 shows the contextually relevant message of “Here are some Tips” 4810 when the underlined topic of “Eating Out” is selected. Additionally, on-screen contextually relevant messages may be displayed for underlined words and phrases within the displayed texts of the underlined topics, shown in FIGS. 47A-47L Links to other web sites, concerning kidney disease, may also be located within the texts of the underlined topics, shown in FIGS. 47A-471 . At the bottom of the text of each underlined topic, shown in FIGS. 47A-471 is an underlined phrase “Return to Top” that when selected returns the patient to the top of “Daily Life, Food, Fluids, Meds and FUN” shown in FIG. 47A .
[0182] When a kidney disease patient selects the “contacts” icon 3238 of FIG. 32 or any other patient screen having a green frame 3202 , the screen changes to that of a graphic and pictorial representation of the clinic's kidney disease treatment and monitoring team, as shown in FIG. 49 . If the patient selects a team member's picture icon 4920 - 4940 , a short biographical sketch (not shown) of the team member may appear on the screen. This biographical sketch helps to familiarize the patient with the clinicians handling the patient's case. If the email access icon 4922 - 4942 is selected, a dialog box containing the corresponding email or message address of the selected team member where that team member can be reached is displayed. If the patient selects the “Support Group” 4910 icon, the screen may show a dialogue box (not shown) containing the support group's e-mail or message address where the patient may chat with others having the same chronic illness.
[0183] When an authorized healthcare practitioner of the clinic signs into the clinic by entering his or her name and a password on the clipboard shown in FIG. 7 , the screen automatically changes to display information concerning the practitioner's patient selection in the central display area 5010 of the main practitioner data screen's 5000 , as shown in FIG. 50 . Information concerning the practitioner's patient selection may also be displayed by selecting the animated “alerts and reminders” 5032 icon. The background 810 of the left side border of the frame 5002 may be, for example, blue, indicating that the practitioner's patient selection is for those patients enrolled in the diabetes clinic, green, indicating that the practitioner's patient selection is for those patients enrolled in the kidney disease clinic, or another color for some other chronic illness or related clinic. In FIG. 50 , for the practitioner's patients within the diabetes clinic, the main practitioner data screen 5000 can include a message list icon 5031 , while the left side border of the frame 5002 may include, for example, icons for “alerts and reminders” 5032 , “register patients or practitioners” 5033 , “enter patient's lab results” 5034 , “patient reminders” 5035 , “On-line chatroom” 5036 , “education” 5037 , “contacts” 5038 , and “logout” 5039 , that change the information displayed in the central display area of the main practitioner data screen. When selected, each of the icons 5031 - 5039 may be identified by an on-screen contextually relevant message when the on-screen indicator is placed over that icon. Additionally, a cumulative count of new messages for the healthcare practitioner from all of the patients of that healthcare practitioner can be presented on this screen, for example, located on the message list. A link to the messaging screen 7100 is provided by the message list icon 5031 attached to the count.
[0184] The central display area 5010 of the main practitioner data screen 5000 is used by a healthcare practitioner to select a patient whose data the healthcare practitioner would like to review. As shown in FIG. 50 , there are three lists of patients the healthcare practitioner can select a patient from. A first, an all patients list box 5024 lists all patients. A second, or alerts list box 5020 , lists only those patients to whom alerts have been sent. A third, or new data list box 5022 , lists only those patients that have submitted new data, such as, for example, blood glucose data, peritoneal dialysis data or clinical data from other chronic illness monitor device.
[0185] Selecting a patient's records for review by the healthcare practitioner may be prioritized by allowing the healthcare practitioner to choose patient records listed in, for example, the alerts list box 5020 , that contains a list of those patients to whom alerts have been sent. For example, in various exemplary embodiments, such as that shown in FIG. 50 , patients are prioritized based on those requiring attention and among all patients. Those patients requiring higher priority attention include those with active alerts and those with new data. The patients with active alerts and/or new data appear in the alerts list box 5020 or new data box 5022 and the label for the alerts list box 5020 is presented in red. New data, for example, includes blood glucose data (for a diabetic patient) sent in that has not been reviewed by a healthcare practitioner and lab data that has not been reviewed. Selecting a patient from the list contain in the alerts list box 5020 or new data box 5022 brings up the messages screen 5100 , shown in FIG. 51 , for that patient, displaying the alerts contained in the alerts list box 5020 , any messages, and reminders sent to that patient. This also removes that patient from the list contained in the alerts list box 5020 and the new data box 5022 .
[0186] In various exemplary embodiments, the reasons for alerts may include, for example, one or more of the average blood glucose level being greater than site/patient configurable value, the number of days since receiving new data being greater than site/patient configurable value, the HbAIC value being greater than site/patient configurable value, more than 3 hypoglycemic events having occurred within site/patient configurable time frame, and/or more than 6 hyperglycemic events having occurred within site/patient configurable time frame.
[0187] Additionally, patients are prioritized based on new data and appear in the new data list box 5022 with the label for the box presented in green. Selecting a patient from this list brings up the messages screen 5100 , shown in FIG. 51A , for that patient. The messages screen 5100 displays that patient's alerts, messages, and reminders and removes that patient from the alert list box 5020 and the new data list box 5022 . All patients assigned to the healthcare practitioner appear in the all patients list box 5024 and the label for all patients list the box is 5024 presented in blue. Selecting a patient from this list brings up the patient's log book as the initial screen, but does not remove that patient from the list contained in the alerts list box 5020 or the new data list box 5022 if that patient is contained in that list.
[0188] After selecting a patient's name from the list of patients contained in the alerts list box 5020 or the new data list box 5022 , information concerning “ALERTS:” 5150 , “MESSAGES:” 5160 and “REMINDERS:” 5170 for the selected patient is displayed. as shown in FIG. 51A for a diabetic patient, and for “ALERTS:” 5190 , as shown in Fig. SIB for a kidney disease patient. Alternatively, the healthcare practitioner may select patient records from, for example, the all patients list box 5024 , as shown in Fig SO.
[0189] In FIG. 51A , the upper border of the frame 5102 for diabetic patients may include a patient's picture 5101 , the patient's underlined name 5105 , date of birth 5107 , and icons accessing the diabetic patient's “Lab Results” 5130 (see FIG. 21 ), “Blood Sugar Log” 5132 (see FIG. 15 ), “Medication” 5134 (see FIG. 22 ), “Blood Pressure Log” 5138 (see FIG. 25 ), “Exercise Log” 5136 (see FIG. 24 ), “Data Summary and Healthcare practitioner Comments” 5139 (see FIG. 26 ) and “Message List” 5140 (see FIG. 68 ) as described above for information displayed for diabetic patients. In FIG. 51B , the icons access the kidney patient's “Lab Results” 5158 (see FIG. 36 ), “Automated Cycler Flow Sheet” 5152 (see FIG. 34 ), and “Medications” 5154 (see FIG. 37 ) and the message list 5156 . Selecting the patient's picture 5101 automatically presents a screen that allows the healthcare practitioner to send a message to the patient. When the on-screen indicator is placed over the primary care healthcare practitioner's icon 5170 , the patient's primary care healthcare practitioner is identified by name. Selecting the primary care healthcare practitioner's icon 5170 may connect the clinic healthcare practitioner to the patient's primary care healthcare practitioner by automatically providing a screen which allows the clinic healthcare practitioner to send a message to the patient's primary care healthcare practitioner.
[0190] Selecting the “Medication” icon 5134 for the diabetic patient of FIG. 5 IA automatically changes the information displayed to an insulin prescription table 5210 , a number of icons located above the insulin prescription table 5210 and the date the medication is being prescribed, as shown in FIG. 52 . These icons include an insulin medication icon 5235 , an oral medication icon 5237 and an other medications icon 5239 . The date insulin is prescribed and the insulin prescription table 5210 is also displayed by selecting the insulin medication icon 5235 , which is identified by an on-screen message when the on-screen indicator is placed over the insulin medication icon 5235 . The patient's clinic healthcare practitioner may review previous insulin prescriptions by selecting the left-facing arrow 5215 , which is identified by the on-screen message of “previous prescription” when the on-screen indicator is placed over the arrow 5215 . After reviewing a previous insulin prescription, the healthcare practitioner may advance the prescription date and the insulin prescription table 5210 by selecting a right-facing arrow (not shown), which is identified by the on-screen message of “next prescription” when the on-screen indicator is placed over the right-facing arrow.
[0191] The healthcare practitioner enters a new insulin prescription for the diabetic patient into the insulin prescription table 5210 of FIG. 52 by entering data into, for example, data input entry boxes 5250 , from the healthcare practitioner's data terminal 130 . After entering data for a new prescription into the insulin prescription table 5210 , the healthcare practitioner may select the “Update” button 5255 to create the new prescription table, which is automatically dated and timed at the time of the updated entry.
[0192] For diabetic patients having an insulin pump, the information displayed upon selection of the insulin medication icon 5235 automatically shows a basal infusion data table 5310 , a meal/bolus table 5320 , and information relating to supplemental insulin and extra food convergence, as shown in FIG. 53 The healthcare practitioner enters the new insulin pump prescription data into the basal infusion data table 5310 and meal/bolus table 5320 by, for example, drop down list boxes 5315 or data entry input boxes 5325 , and the data relating to supplemental insulin and extra food convergence into their, for example, data entry boxes 5335 . To create a new insulin pump prescription, the healthcare practitioner may select the “Update” 5355 button at the bottom of the display of FIG. 53 .
[0193] Selecting the oral medications 5237 icon, for diabetic patients, located above the insulin prescription table 5210 of FIG. 52 , automatically changes the information displayed to a prescription date for oral medications and an oral medication prescription table 5410 , as shown in FIG. 54 . The healthcare practitioner may review previously prescribed oral medications by selecting the left-facing arrow 5415 and after review may return to the current oral medication prescription table 5410 by selecting the right-facing arrow (not shown), as described above. Entry of the new oral prescription information may be facilitated by prescribing drugs that are categorized by their function, for example, drugs which enhance insulin secretion, a drug which decreases glucose production by the liver, drugs which slow the absorption of sugars, and glitazones. Entry of data into the oral prescription table 5410 may also be facilitated by allowing the healthcare practitioner to rapidly select a particular drug within a functional category of drugs and to enter prescription information, for example, dosage, tablets per dose and frequency taken into an appropriate, for example, drop down list box 545 , as shown in FIG. 55 For example, a 500 mg dose of the drug, Glucophage, may be entered into the drop down list box 5450 , as shown in FIG. 54 .
[0194] Selecting the Medications icon 5154 for kidney disease patients, of FIG. 5113 , automatically changes the information displayed to a “Medications” table 3710 and “Other Medications” table 3720 , as described above and shown in FIG. 37 . The healthcare practitioner may enter new prescriptions for medications by entering the appropriate data into the “Medications” table 3710 by, for example, a number of data entry input boxes (not shown), corresponding to the “Medications” table's 3710 data. The healthcare practitioner may, similarly, view the appropriate data entered by the patient into the “Other Medications” table 3720 .
[0195] Selecting the “Other medications” icon 5239 of FIG. 52 automatically changes the information displayed to the “Other medications” table 5450 , which corresponds to the diabetic patient's “Other medications” table 1730 or 1732 , shown in FIG. 22 , for a practitioner selected diabetic patient and to the kidney disease patient's “Other medications” table 3720 , shown in FIG. 37 , for a practitioner selected kidney disease patient. These other medications may be non-prescription medications or they may be medications that have been prescribed by other healthcare practitioners for medical conditions not related to the patient's chronic illnesses. The clinic healthcare practitioner may wish to review these medications for possible adverse drug interactions with those drugs the healthcare practitioner has prescribed, for possible side effects, or for other medical reasons.
[0196] Selecting the animated “Exercise Log” icon 5136 of FIG. 51A for the diabetic patient automatically changes the information displayed to a patient exercise log, as described above and shown in FIG. 24 . The healthcare practitioner may view comments that the patient may have entered into the exercise log using, for example, a data entry input box, that is displayed above the patient's Exercise Log 1910 or 1928 of FIG. 24 .
[0197] Selecting the “Blood Pressure” icon 5138 of FIG. 51A for the diabetic patient, automatically changes the information displayed to a patient's Blood Pressure Log 2010 , as described above and shown in FIG. 25 . The healthcare practitioner may view comments that the patient may have entered into the blood pressure log using, for example, a data entry input box, that is displayed above the patient's Blood Pressure Log 2010 of FIG. 25 .
[0198] Selecting the “Data Summary and Healthcare practitioner Comments” icon 5139 shown in FIG. 51A for any data screen of the diabetic clinic portion of the clinic system 200 automatically changes the information displayed to a table 5610 , as shown in FIG. 56 , corresponding to the patient's tabular summary 2610 of the blood glucose values for a range of dates, as described above and shown in FIG. 26 . The clinic healthcare practitioner may enter comments into the “Healthcare practitioner Comments” column of the table 5610 by, for example, a data input entry box 5650 , via the keyboard of the healthcare practitioner data terminal 130 , as shown in FIG. 56 . In various exemplary embodiments, if a healthcare practitioner writes a comment to the patient in the table 5610 , then the record appears with a yellow background in the healthcare practitioner's view until the patient views the comment. Such communication between the healthcare practitioner and patient enhances the patient's compliance in the monitoring program and reflects the type of communication between healthcare practitioner and patient that would occur during an actual clinic visit.
[0199] The healthcare practitioner may also review the data presented in the table 5610 of FIG. 56 that corresponds to the data of the patient's blood sugar log 1510 of FIG. 15 , by selecting the data presentation icons 5620 - 5626 above the table 5610 .
[0200] The “Line Chart” icon 5620 allows the blood sugar log data to be presented as a linear graph; the “Histograms” icon 5622 as histograms; the “Pie Chart” icon 5624 as a pie chart; and the “Multiple pie charts” icon 5626 as multiple pie charts, as described above and shown in FIGS. 17-20
[0201] Selecting the healthcare practitioner “Message List” icon 5140 of FIG. 51A changes the display to the healthcare practitioner message list screen 7100 as shown in FIG. 71 . The healthcare practitioner is presented with a list of messages sent by the healthcare practitioner's patients or by the healthcare practitioner, as shown in FIG. 71 . Information, such as the date a message was sent, to whom the message was sent, who sent the message, and the subject/title of the message may be presented. However, if the healthcare practitioner has selected a particular patient to review that patient's records using one of the list boxes 5020 - 5024 , only those messages concerning that particular patient are presented in a patient-specific healthcare message list screen 7100 , as shown in FIG. 73 . Additionally, in various exemplary embodiments, to distinguish unread from read messages, the unread messages in the list can be preceded by an asterisk, which can be color coded to increase its visibility.
[0202] When the healthcare practitioner selects one of the underlined subject/titles, the clinical management system retrieves the selected message for the healthcare practitioner, as shown in FIG. 72 . A message screen 7210 appears with information such as the date the message was sent, to whom the message is addressed, who sent the message, the subject/title of the message and the message itself. If the entire message does not fit within the message screen 7210 , horizontal and/or vertical scroll bars are presented for the healthcare practitioner to scroll through the message (not shown). At the end of the message there is a “Reply” button 7220 and a “Close” button 7230 . When selected, the “Reply” button 7220 allows the healthcare practitioner to send a response message to whomever sent the message. The “Close” button 7230 allows the healthcare practitioner to exit the message list screen 7210 and return the healthcare practitioner to the healthcare practitioner message list screen 7100 of FIG. 73 .
[0203] The healthcare practitioner may also create and add a new message using the healthcare practitioner message list screen 7100 . The healthcare practitioner can use this screen to create a message directed to any patient that is assigned to that healthcare practitioner. The healthcare practitioner selects a “Select a Patient” drop down list box 7110 . The “Select a Patient” drop down list box 7110 provides a lists of the patients in the clinical management system for chronic diseases 100 assigned to that healthcare practitioner. The healthcare practitioner then selects the patient that the healthcare practitioner wishes to address the message to using the list box 7110 . However, if the healthcare practitioner has already selected a particular patient using one of the list boxes 5020 - 5024 , the message is automatically addressed to that patient and the patient-specific healthcare practitioner message list screen 7100 is displayed, as shown in FIG. 73 . The healthcare practitioner does not need to provide this information. Accordingly, the “Select a Patient” drop down list box 7110 does not need to be shown in the patient-specific healthcare practitioner message list screen 7100 shown in FIGS. 73 and 74 . The healthcare practitioner may also provide a subject/title for the message, but this is not required. The healthcare practitioner does this by simply typing in the subject/title in the “Subject” data entry box 7120 .
[0204] If the healthcare practitioner decides to discard the message, has made an error, or wants to change to whom the message is addressed to and/or the subject/title of the message, the healthcare practitioner can select the “Reset” button 7130 . When selected, the “Reset” button 7130 clears to whom the message is addressed to as selected from the “Select a Patient” drop down list box 7110 and clears the “Subject” data entry box 7120 . The function of the “Reset” button 7130 can also be accomplished by selecting a different individual from the “Select a Patient” drop down list box 7110 for whom the message is addressed and by backspacing over the incorrect data entry and then typing the correct data in the “Subject” data entry box 7120 .
[0205] After the healthcare practitioner has selected the patient to address the message and typed a subject/title for the message (optional), the healthcare practitioner selects the “Add Message” button 7140 . When the healthcare practitioner selects the “Add Message” button 7140 , the display changes to the “Add a Message” screen, which is similar to that shown in FIG. 70 . The healthcare practitioner's “Add a Message” screen displays the healthcare practitioner's name as who the message is from, the name of the patient to whom the message is addressed and the subject/title, if provided by the healthcare practitioner. Additionally, there is a message data entry box 7010 , a “Submit” button 7020 , a “Reset” button 7030 , and a “Cancel” button 7040 . The healthcare practitioner then enters his or her message into the message data entry box 7010 by using the keyboard or some other data entry device. Once finished, the healthcare practitioner selects the “Submit” button 7020 to send the message. If the healthcare practitioner is unsatisfied with the inputted message and wishes to discard all of its contents, the healthcare practitioner simply selects the “Reset” button 7030 or backspaces over the undesired portions of the message. However, if the healthcare practitioner wishes to disregard sending a message all together, the healthcare practitioner can select the “Cancel” button 7040 . This returns the healthcare practitioner to the healthcare practitioner message list screen 7100 shown in FIGS. 71-74 .
[0206] Selecting the “register patients or practitioners” icon 5033 of FIG. 50 of the main practitioner data screen automatically changes the display to that shown in FIG. 57 . When the healthcare practitioner selects the underlined “Practitioners” 5710 of FIG. 57 , the display automatically changes to a “Practitioner Registration” form, as shown in FIG. 58 . The “Practitioner Registration” form 5800 may include data entry input boxes 5810 for the entry of, for example, enrollment date, last name, first name, address, city, state, zip code, home and cell phones, pager, and c-mail or message address. The “Practitioner Registration” form 5800 may also include drop down list boxes 5820 for the entry of, for example, the healthcare practitioner's specialty and the occupation of the healthcare practitioner, for example, healthcare practitioner, nurse, etc. The specialty and the occupation of the healthcare practitioner dictate which patients they will interact with through the system and their permissions, for example, viewing types of patient data, and privileges, for example, entering new prescriptions for medications, on the system.
[0207] When the healthcare practitioner selects the underlined “Patients” icon 5720 shown in FIG. 57 , the display automatically changes to a “Patient Registration Form”, as shown in FIG. 59 . The “Patient Registration Form” 5900 may include data entry input boxes 5910 for the entry of, for example, last name, first name, medical record number, address, city, state, zip code, home phone number, work phone number, cell phone number, e-mail or message address, emergency contact, relationship, address. phone number, date of birth, race, gender, educational level, and employment. The “Patient Registration Form” 5900 may also include drop down list boxes 5920 for the entry of, for example, marital status, primary care healthcare practitioner, specialist, nurse, primary disease, comorbidities, and allergies_Selecting the underlined phrases of “Add Physician”, “Add Specialist”, and “Add Nurse” may allow these healthcare practitioners to be added to their respective drop down list boxes 5920 for entry into the “Patient Registration Form” 5900 . A dialogue box 5930 may also be available to add comments. Selection of a specialist dictates which healthcare practitioner and associated healthcare practitioners are responsible for the patient's care.
[0208] Selecting the “enter patient's lab results” icon 5034 of FIG. 50 of the main practitioner data screen 5000 automatically changes the display to that shown in FIG. 60 for diabetic patients, and to that shown in FIG. 61 for kidney disease patients. The “Lab Values Entry for Diabetes Patients” screen 6000 shown in FIG. 60 may include, for example, drop down list boxes 6010 , usable to enter the date for which the lab values are being entered, and usable to select the patient whose lab values are being entered. Additionally, the “Lab Values Entry for Diabetes Patients” display 6000 may include, for example, data entry input boxes 6020 , for the entry of tab values, such as, HbAIC, cholesterol, HDL, LDL, triglyceride and urine microalbumin, as described above in relation to the patient's “Lab Results” table 2110 shown in FIG. 21 .
[0209] In the “Lab Values Entry for Dialysis Patients” screen 6100 shown in FIG. 61 , the healthcare practitioner may also enter the date for which the lab values are being entered using, for example, drop down list boxes 6110 , and may select the patient whose lab values are being entered using, for example, a drop down list box 6120 . Additionally, a first option button 6130 indicates that no hospitalization is required for the test and a second option button 6134 indicates that hospitalization is required for the test. After selecting the “Go” button 6138 , the screen changes to display the continued “Lab Values Entry for Dialysis Patients” screen 6200 .
[0210] As shown in FIG. 62 , the “Lab Values Entry for Dialysis Patients” screen 6200 shows, for example, multiple data entry input boxes 6210 , by which laboratory test results may be entered by the healthcare practitioner. The entered laboratory test results may include but are not limited to, for example, Kt/V, albumin, calcium, creatinine, ferritin, glucose, HGB×3, iron, phosphate, potassium, PTH, TIBC, TSH, T3 uptake. T4 total, T7/Ffl, cholesterol—FIDL, LDL, triglycerides, HBSAG, HBSAB, HEPCAB, and HgbA1C. The entered laboratory results are then displayed to the kidney disease patient in the “Lab Results” table 3610 , discussed above and shown in FIG. 36 .
[0211] Selecting the “patient reminders” icon 5035 of FIG. 50 of the main practitioner data screen 5000 automatically changes to that shown in FIG. 63 for diabetic patients, and to that shown in FIG. 64 for kidney disease patients.
[0212] The “Patient Reminders” screen 6300 shown in FIG. 63 for the diabetic patient may include the current date and data which is to be entered by the healthcare practitioner including, but not limited to, for example, the selected patient, the date of the patient's visit and when the next visit is scheduled, the date of requested lab work and when the next lab work is scheduled, the date of requested HbAlC test values and when the next HbAlC test is scheduled, the date of a foot exam and the next scheduled foot exam, the date of an eye exam and the next scheduled eye exam. Selecting the patient and entering scheduled dates for visits, tests and exams may be facilitated by, for example, drop down list boxes 6310 that provide selections for the month, date and year, as shown in FIG. 63 . Selecting the next scheduled date for visits, tests and exams may be facilitated by, for example, option buttons 6340 or data entry input boxes 6320 , as also shown in FIG. 63 . The entered patient reminders are displayed to the patient in the main patient data screen for diabetic patients 700 , as described above and shown in FIG. 10 .
[0213] The “Patient Reminders” screen 6400 shown in FIG. 64 for the kidney disease patient may include the current date and, for example, a drop down list box 6410 for selecting the patient to whom the reminder is to be addressed. After selecting a patient, the main practitioner data screen changes to that shown in FIG. 65 . The continued “Patient Reminders” screen 6500 shown in FIG. 65 may include the current date and the selected patient's name, and a number of, for example, drop down list boxes 6510 , that facilitate entries of month, date and year for various reminders. The reminder dates that are entered for the kidney disease patient may include, but are not limited to a clinic visit, Kt/V test, lab work, chest X-ray, EKG, PPD/TB risk appraisal, a home visit, gynecology/mammogram exam, patient continuing education, medical history and physical, nursing assessment, long term care plan/conference, short term care plan/conference, and transfer set change. The entered patient reminders are displayed to the patient in the main patient data screen 3200 for kidney disease patients, as described above but not shown in FIG. 32 .
[0214] Selecting the “On-line chatroom” icon 5036 of FIG. 50 of the main practitioner data screen 5000 automatically changes the screen to that of a message dialogue box (not shown) including the e-mail or message address of the patient support group for the particular chronic illness that the healthcare practitioner is managing. The healthcare practitioner may then interact with the patient support group, offering suggestions for daily living, explaining medical procedures, correcting misunderstandings, etc.
[0215] When a visitor logs on to the system, he or she may enter the clinic lobby 400 of FIG. 4 and proceed to open the door icon 404 of the public library, as shown in FIG. 5 . Selecting the door icon 404 changes the screen to that of the main visitor data screen 6600 , as shown in FIG. 66 . The main visitor data screen 6600 includes, for example, a frame 6602 along its upper and left-side borders that has a light green background 810 and a central display area 6610 .
[0216] The upper border of the frame 6602 may include the name of the project and an icon 6640 that, when selected, connects the visitor to another screen (not shown) that is accessible to visitors. The left side of the border of the frame 6602 may include, for example, icons for “Description” 6630 , “Diabetes” 6631 , “Kidney Disease” 6632 , “News Items” 6633 , “Public” 6634 , and “Main Page” 6635 . The central display area 6610 may include the latest news items concerning the chronic illnesses that the clinic manages. For example, if the underlined “Diabetes News” 6620 is selected, the screen will change to display the latest diabetes news in the central display area 6610 , corresponding to that news displayed in the patient's education site, as shown in FIG. 13 . The visitor may also select archival news by selecting the archival article from, for example, a drop down list box 6625 , labeled “Diabetes Archive”. The visitor may similarly access the latest news item and archival news items by selecting the underlined “Kidney Disease News” 6630 or the drop down list box 6635 , labeled “Kidney Disease Archive”.
[0217] Selecting the “Description” icon 6630 of FIG. 66 changes the screen to display a project description screen 6700 , as shown in FIGS. 67A-67G . The project description may include multiple pictures 6705 which are sequentially displayed while the project description is displayed. The project description may also include links to other sites within the clinic system 200 , Internet sites or World Wide Web sites for further description of the project.
[0218] Selecting the “Diabetes” icon 6631 of FIG. 66 changes the screen to display the diabetes education site, as described above and shown in FIG. 29
[0219] Selecting the “Kidney Disease” icon 6632 of FIG. 66 changes the screen to display the PD education information, as described above and shown in FIG. 38 .
[0220] Selecting the “News Item” icon 6633 changes the screen to display the main visitor data screen 6600 of FIG. 66 .
[0221] By selecting the “Main Page” icon 6635 of FIG. 66 , the visitor returns to the clinic lobby 400 of FIG. 4 .
[0222] While this invention has been described in conjunction with the specific embodiments outlined above, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, the preferred embodiments of the invention, as set forth above, are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit and the scope of the invention. | Patients with chronic illnesses resist using conventional automated healthcare management systems to supply necessary clinical data because such systems feel impersonal, preferring to actually visit a clinic where the patient interacts with various healthcare practitioners. In this invention, the patient interacts with a clinical management system via a series of initial GUI screens that replicate the experience of actually visiting the clinic. Additional screens allow the patient to submit clinical information, to communicate with that patient's healthcare practitioner and other healthcare practitioners, to access management information that aids the patient in managing that patient's chronic illness, and to access educational information regarding that chronic illness. The clinical management system may be used to manage a plurality of different chronic illnesses while providing a consistent look and feel to the screens. At least one appearance characteristic can be altered to indicate the particular chronic illness to which a screen applies. | 6 |
RELATED APPLICATIONS
[0001] The present application claims the benefit of U.S. Provisional Patent Application No. 61/676,774, filed on Jul. 27, 2012, which is herein incorporated by reference in its entirety.
BACKGROUND
[0002] 1. Field of the Invention
[0003] The present invention relates to non-explosive mining techniques for mining operations.
[0004] 2. Description of the Related Art
[0005] Non-explosive mining techniques offer an alternative to the increasing costs associated with explosive excavation. Explosive excavation is a cyclic process requiring several steps: blast holes are drilled into a rock face, explosive charges are loaded into the blast holes, the surrounding area is evacuated, the explosives are detonated, and the area is ventilated and cleared. Explosive excavation incurs significant costs associated with security and environmental damage, such as the generation of toxic gases.
[0006] Mechanized non-explosive mining may be carried out with fewer personnel and reduce the security and environmental costs of high explosives. This approach also increases processing efficiency by allowing selective mining of the ore veins. Mechanical impact hammers can be used to excavate hard rock, but the process is slow; the hammers and support equipment are very heavy and the impact tools wear out quickly.
[0007] Another example of mechanized non-explosive mining is an impact piston water cannon, in which compressed air drives a heavy piston that impacts and pushes a quantity, or slug, of water. The water slug impacts the rock face to cause erosion and excavation. While impact piston devices have been shown to generate high pressures, their use in commercial excavation work has been limited due to the significant wear on the pistons and cylinders of the devices. Further, the mechanical system that must be maneuvered at the rock face is prohibitively bulky.
[0008] As an alternative to an impact piston cannon, a compressed water cannon designed for hard rock mining is described in “A Hydraulic Pulse Generator for Non-Explosive Excavation,” by Kolle, J. J., in Mining Engineering , July 1997, pg. 64-72, which is herein incorporated by reference in its entirety. The compressed water cannon comprises a heavy pressure vessel charged to very high pressures (100-400 MPa, or 14,500-60,000 psi). At these pressures, the water is substantially compressed and stores a considerable amount of energy. After charging, the water is discharged through a fast-opening valve, which causes the resulting pulse of water to impact the rock face. Discharge of a 100 to 400 MPa pulse onto the face of hard rock will have little or no effect in rock fragmentation. To perform rock fragmentation, the compressed water cannon nozzle must be inserted and discharged into a pre-drilled blast hole. Discharge of the pulse into the blast hole generates tensile stresses in the rock and allows effective excavation. The productivity and flexibility of this approach, called bench blasting, is limited because drilling is the most time-consuming aspect of the operation.
[0009] As reported by Mauer, W. C. in Advanced Drilling Techniques , pg. 302-348, Petroleum Publishing Inc., 1980, hyper-pressure pulses that are over 1 GPa, or 145,000 psi, have been shown to efficiently excavate hard rock by cratering, eliminating the need for a pre-drilled blast hole. Accordingly, it would be desirable to enable a compressed water cannon to be employed without the need for a pre-drilled blast hole.
SUMMARY OF THE INVENTION
[0010] In accordance with the present invention, the problems above are addressed with a hyper-pressure water cannon. The hyper-pressure water cannon, or pulse excavator, is able to discharge fluid pulses at extremely high velocities to fracture a rock face in excavation applications. A compressed water cannon can be used to generate hyper-pressure pulses by discharging the pulse into a straight nozzle section which leads to a convergent tapered nozzle. The water cannon design is relatively compact, and the pulse generator can readily be maneuvered to cover the face of an excavation as part of a mobile mining system. As an alternative, the pulse could be generated by a propellant gun.
[0011] Hyper-pressure pulse excavation, or cratering, is an application of the water cannon that eliminates the need for drilling a blast hole. The high-velocity water pulse is discharged into a combination straight and tapered nozzle that can amplify the peak pulse pressure by a factor of 10 or more.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Various aspects and attendant advantages of one or more exemplary embodiments and modifications thereto will become more readily appreciated as the same becomes better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:
[0013] FIG. 1A illustrates a cross-sectional schematic view of a complete hyper-pressure pulse excavator 100 including an electrical trigger, vent valve assembly 150 , pressure vessel 110 , and two-part nozzle assembly ( 120 and 132 );
[0014] FIGS. 1B-1E illustrate the hyper-pressure pulse excavator 100 in various stages of preparing to fire a water pulse;
[0015] FIGS. 2A-2C illustrate exemplary measurements for various sizes of the hyper-pressure pulse excavator 100 ;
[0016] FIGS. 3A-3C show nozzle inlet pulse measurement charts based on a 230 MPa discharge from the exemplary embodiment shown in FIG. 2A ;
[0017] FIG. 4 illustrates the process of unsteady flow acceleration of a water pulse through straight and tapered nozzle sections;
[0018] FIG. 5A-5C illustrate the hyper-pressure outlet pulse measurement charts; and
[0019] FIG. 5D shows a chart displaying an exemplary exponentially convergent tapered nozzle profile.
[0020] FIG. 5E shows a chart displaying the internal pressure profiles inside an exponentially tapered nozzle at three locations of the fluid pulse.
DETAILED DESCRIPTION
[0021] It is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless limited otherwise, the terms “connected,” “coupled,” and “mounted,” and variations thereof herein are used broadly and encompass direct and indirect connections, couplings, and mountings. In addition, the terms “connected” and “coupled” and variations thereof are not restricted to physical or mechanical connections or couplings.
[0022] FIG. 1A illustrates a schematic of an exemplary hyper-pressure pulse excavator 100 , shown after firing a water pulse. The pulse excavator 100 includes a pressure vessel 110 and a two-part nozzle assembly, which includes a straight nozzle section 120 and a tapered nozzle section 132 within a nozzle housing 130 . The pressure vessel 110 includes a supply tube 112 , a poppet sleeve 114 , a sleeve port 116 , and a poppet 118 . When poppet 118 is closed, it sits against poppet seat 119 at the end of pressure vessel 110 . When the poppet 118 is opened, or pushed away from the poppet seat 119 , the poppet 118 and poppet seat 119 together act as a dump valve, and pressurized fluid in the pressure vessel 110 is discharged into the straight nozzle section 120 . The junction of the pressure vessel 110 and the straight nozzle section 120 includes an opening connected to an air compressor 126 and a second opening connected to a metering pump 122 and a gel supply 124 . The electrical subsystem of the pulse excavator 100 includes a push button switch 170 , arm light 172 , arm switch 174 , relay switch 176 , and the solenoid valve 180 (including battery power for the solenoid).
[0023] Fluids within the hyper-pressure pulse excavator 100 build to extremely high pressures and must be discharged very quickly to effectively crater rock. Additionally, an excavating tool such as the pulse excavator 100 should not be so unwieldy and large as to prevent moving the tool around the rock face. Off-the-shelf valve systems offering suitable performance in both size and speed for such operation are typically not available. Instead, as shown in FIG. 1A , a series, or system, of cascading valves leading to the pressure vessel 110 can be used. Each subsequent stage the handles progressively larger volumes and pressures, and the final stage opens the poppet 118 in the pressure vessel 110 . While FIG. 1A shows an exemplary series of cascading valves, different types and arrangements of valves may be used to operate the poppet 118 in the pressure vessel 110 .
[0024] The series of cascading valves includes the solenoid valve 180 , the hydraulic pump return valve 146 , the pressurized water supply valve 184 , and the vent valve assembly 150 . In operation, the accumulator 140 , return tank 142 , and hydraulic pump 148 , and isolator piston 144 serve to maintain a pressure on the vent valve assembly 150 until the solenoid valve 180 can open. In the discharged state after firing, the hydraulic pump return valve 146 is open, resulting in water pressure from pressurized water supply 182 moving the isolator piston 144 to its upper position. The hydraulic pump 148 is also shown with a return tank 142 and an accumulator 140 . Additionally, the pressurized water supply valve 184 is open, and the solenoid valve 180 to the tank 178 is closed and unarmed. Additional details of the valve operation can be seen in U.S. Pat. No. 5,000,516 to Kolle, entitled “Apparatus for rapidly generating pressure pulses for demolition of rock having reduced pressure head loss and component wear,” issued Mar. 19, 1991, which is incorporated herein in its entirety.
[0025] In a preferred embodiment of the invention, the pulse excavator 100 further includes a vent valve assembly 150 . The vent valve assembly 150 includes a vent valve housing 158 with vent valve vents 160 . Although the pressurized water supply valve 184 is open, the vent valve piston 156 in the vent valve housing 158 is not pressurized to a sufficient level to tightly hold the poppet 154 against its seat 152 . The vent valve assembly 150 is connected to the supply tube 112 of the pressure vessel 110 . An ultra-high pressure pump 162 with a water inlet 164 is also coupled to the vent valve assembly.
[0026] FIG. 1B shows the system ready to fire a water, or water-based, pulse. The pressurized water supply valve 184 is closed. The hydraulic pump return valve 146 of the hydraulic pump 148 is closed, and the hydraulic pump 148 has been actuated, pressurizing the top of the isolator piston 144 with oil, water, or another fluid. The other side of the isolator piston 144 contains water. When the top of the isolator piston 144 is pressurized, the left side of the vent valve piston 156 is pressurized, causing the vent valve piston 156 to push against and hold the vent valve poppet 154 against the vent valve poppet seat 152 . The ultra-high pressure pump 162 is then actuated and used to charge the pressure vessel 110 through the supply tube 112 into the cavity between the poppet sleeve 114 and poppet 118 within the pressure vessel 110 . This pressurization pushes the poppet 118 against its seat 119 at the outlet of the pressure vessel 110 , closing the fluid path to the straight nozzle section 120 . With the poppet 118 seated against the straight nozzle section 120 , the sleeve port 116 is exposed, allowing water to flow into the pressure vessel 110 through the supply tube 112 . As more water is pumped into the pressure vessel 110 , the pressure within the pressure vessel 110 builds, typically to 100 to 400 MPa.
[0027] In parallel, the air compressor 126 may supply compressed air to the straight nozzle section 120 . This helps to empty the straight nozzle section 120 and tapered nozzle section 132 of any residual water (for example, from the previous water pulse firing). In one embodiment, a small volume of a gelled fluid 125 such as agar, polyacrylamide, or bentonite gel may be metered using the metering pump 122 from into the straight nozzle section 120 immediately below the poppet seat 119 . This precharges the straight nozzle section 120 with the gelled fluid 125 , allowing the gelled fluid 125 to be on the leading edge of the fluid pulse when the pulse excavator 100 fires. This gelled fluid may also be weighted with a substance such as salt to increase its density. The arm switch 174 electrical circuit is then armed, the air valve of the air compressor 126 is closed, and the system 100 is ready to fire.
[0028] FIG. 1C illustrates the start of the firing sequence. The push button switch 170 is closed or depressed, causing the relay switch 176 to close and the solenoid valve 180 to open. As the solenoid valve 180 opens, the isolator piston 144 moves down at constant pressure. The opening time of the solenoid valve 180 is preferably very short, such as on the order of 100 milliseconds so, but there is a limit to the opening speed of solenoid valves. The isolator piston 144 and accumulator 140 assembly give the solenoid valve 180 time to open fully by maintaining pressure on the vent valve poppet 154 before the isolator piston 144 reaches the end of its travel. As soon as the isolator piston 144 reaches the end of its travel, the left side of the vent valve piston 156 is depressurized, and the ultra-high pressure on the face of the vent valve poppet 154 causes it to open.
[0029] FIG. 1D illustrates the continuation of the firing sequence, with the vent valve poppet 154 fully open. This depressurizes the water in the supply tube 112 and the volume of water in the cavity between the poppet 118 and poppet sleeve 114 in the pressure vessel 110 . Because the section area of the poppet 118 is larger than the seal area of the poppet seat at the base of the straight nozzle section 120 , a large force lifts the poppet 114 from its seat. The poppet 118 opens very quickly, acting like a fast-opening dump valve and discharging the compressed water from the body of the pressure vessel 110 . Once the poppet 118 is open, the water contained in the pressure vessel 110 begins accelerating through the straight nozzle section 120 . As mentioned above, if gel has been metered out into the straight nozzle section 120 , the gel slug is also pushed by the accelerating water pulse. The gel slug and water slug are pushed through the straight nozzle section 120 as well as the nozzle housing 130 , as shown in FIG. 1E . The nozzle housing 130 contains a tapered nozzle section 132 , which tapers from the diameter of the opening of the straight nozzle section 120 .
[0030] Due to the unsteady flow phenomenon, the gel and water slugs are extruded though the tapered nozzle section 132 at extremely high velocities. The process of unsteady flow acceleration is illustrated in FIG. 4 . When a fluid pulse moving at uniform velocity, U o , enters a tapered nozzle, the leading edge of the pulse accelerates (U e ), while the trailing edge of the pulse slows (U b ). The velocities can be calculated for a given nozzle profile based on the principles of continuity of momentum and volume. If no gel is used, then the water will be at the leading edge of the pulse. In a preferred embodiment of the invention, the tapered section 132 is exponential.
[0031] Due to the extreme pressures generated in employing this technique, nozzle wear and fatigue of the cannon body are concern for long-term operation. The tapered nozzle section 132 is preferably fabricated from a hard erosion-resistant material such as hardened steel or carbide. This material may be held by a nozzle housing 130 made of high strength steel. The two part construction of the tapered nozzle allows the use of hard, erosion-resistant materials that may have low tensile strength. Conversely, the tapered nozzle can be fabricated from one part if a sufficiently high strength steel is used.
[0032] FIGS. 2A-2C illustrate exemplary dimensional measurements for various sizes of the hyper-pressure pulse excavator 100 . The productivity of hyper-pressure pulse excavation can be expressed in terms of specific energy, which is the ratio of the pulse energy to the volume of rock removed. Increasing the scale of the system increases efficiency substantially, since the specific energy required for breaking is inversely proportional to the rock fragment size. As described above, impact piston cannons provide a means of generating hyper-pressure pulses, but the mechanism for these devices is very bulky and generates large reaction forces. Further, as also described above, their use in commercial excavation work has been limited due to the significant wear on the pistons and cylinders of the devices. The compressed water cannon as described herein can provide the similar pressure levels more efficiently. As described above, the pulse excavator 100 uses the system of cascaded valves to build to sufficient pressure levels. In a smaller embodiment, such as the one seen in FIG. 2A , alternate valve systems, such as a hand valve or a large solenoid valve, may be used. This may allow the pulse excavator 110 to be operated with a single- or dual-level valve system. For larger embodiments, such as the ones seen in FIGS. 2B and 2C , single- or dual-level valve systems will likely not provide the performance required for operation. Additionally, the cascaded valve system allows for smaller valves to be used at the various stages, further allowing for the use of smaller batteries to actuate the solenoid valve 180 .
[0033] The specifications for the exemplary embodiment shown in FIG. 2A of the compressed water cannon for use in hyper-pressure pulse excavation are as follows:
1.8-liter internal volume; 15 kJ @ 240-MPa charge pressure; and 12.7-mm-diameter discharge nozzle.
[0037] The operating pressure of the pressure vessel 110 alone is limited by practical considerations to 100-400 MPa (14,500-60,000 psi). However, the pressure required to effectively break harder rock requires fluid pulses with stagnation pressures above 2 GPa (300,000 psi). As mentioned above, the straight nozzle section 120 and tapered nozzle section 132 are used to amplify the velocities of fluid pulses to achieve the stagnation pressures required to effectively break rock. The diameter of the straight nozzle section 120 may be equal to the diameter of the discharge valve of the pressure vessel 110 . The diameter of the straight nozzle section 120 is smaller than the diameter of the pressure vessel 110 bore—typically, around 20% to 30% of the bore is preferred, though the range could be 10% to 50%.
[0038] The length of the straight nozzle section 120 is determined by observing the discharge characteristics of the pressure vessel 110 without the nozzle section attached. FIG. 3A shows the observed stagnation pressure from a water pulse discharged from the exemplary embodiment shown in FIG. 2A (without the attached nozzle) when the pressure vessel 110 is charged to 230 MPa versus time. Note that the peak stagnation pressure is substantially less than the charge pressure of 230 MPa. Further, the rise time of the pressure release is very fast, on the order of 1-2 ms. The fast rise time is facilitated by the presence of the fast-opening dump valve, such as the poppet valve 118 . FIG. 3B shows the velocity of the pulse as a function of pulse length as calculated from the stagnation pressure profile. A uniform-velocity slug of water is needed to generate a hyper-pressure pulse in a tapered nozzle section 132 . In practice, the velocity of water exiting the cannon valve varies continuously, however a pulse of about 0.5 m length with a velocity of over 500 m/s is generated. The kinetic energy of the pulse rises linearly up to around 0.5 m and then increases at a lower rate. The velocity is slow as the valve opens, peaks after the valve is opened, and then drops as the cannon decompresses. A straight nozzle section 120 accumulates the water in the leading edge of the pulse and allows the higher-velocity fluid to catch up, forming a uniform-velocity slug. Once the slug velocity starts to drop, the slug will stretch and break up.
[0039] Based on a measurement of the discharge pressure of the pressure vessel 110 at 230 MPa, the velocity of the water pulse can be measured against the length of the pulse. To reach efficiencies, pulse velocity and length should be maximized. For the pressure vessel 110 of the exemplary embodiment shown in FIG. 2A , a pulse length of 0.5 meters was chosen based on the chart shown in FIG. 3B . The point representing the pulse length of 0.5 meters in FIG. 3B was selected as maximizing both pulse velocity and length because the pulse velocity begins to decrease more substantially after the pulse length of 0.5 meters. Accordingly, the length of the straight nozzle section 120 was set at 0.5 meters. The final volume of the straight nozzle section 120 may be preferably between 2-10% of the volume of the pressure vessel 110 .
[0040] Given a 20 inch long (i.e., roughly 0.5 meter) slug with a diameter of 0.5 inch, the tapered nozzle parameters may be determined. As mentioned above, the tapered nozzle section 132 accelerates the leading edge of the pulse to hyper velocity through unsteady flow dynamics. Given a convergent tapered nozzle 132 with an arbitrary profile, it is possible to calculate the velocity of the slug of water everywhere as the slug is extruded though the taper by solving the equations for continuity of volume and momentum. This may be determined using a numerical simulation of these continuity equations for various nozzle profiles. The internal pressure along the length of the nozzle can also be calculated from the local acceleration. The details of this calculation are described in Glenn, Lewis A. (1974) “On the dynamics of Hypervelocity liquid jet impact on a flat rigid surface,” Journal of Applied Mathematics and Physics ( ZAMP ), vol. 25.
[0041] A numerical analysis indicates that the exemplary compressed water cannon tool from FIG. 2A can produce a compressed water pulse that is 300-mm in length, traveling at a velocity of about 520 m/s, as shown FIG. 5A . The theoretical profile agrees reasonably well with the observed profile shown in FIG. 3B . The theoretical velocities of the leading and trailing edges (shown as U e and U b , respectively) of this water slug as it moves through the tapered nozzle are shown in FIG. 5B . The leading edge accelerates to over 2000 m/s, while the trailing edge decelerates. The peak velocity drops rapidly, to under 1000 m/s after 200 μsec. In this time the leading edge of the pulse will travel 0.4 m (16 in.). The nozzle should be located at a fraction of this distance from the target to maximize effectiveness. The velocity profiles may be calculated by assuming that the water is an incompressible fluid, although water is compressible at such velocities. The peak velocity of the discharged jet may be limited by the speed of sound in water (around 1500 m/s), which may limit the peak velocities to values lower than those shown in FIG. 5B . The compressed water pulse will convert to a 2-GPa pressure spike in a 150-mm-long convergent tapered nozzle, as shown in FIG. 5B , with 80% energy conversion above 1 GPa, as shown in FIG. 5C .
[0042] An example of the internal pressure profiles inside an exponentially tapered nozzle at three locations of the pulse is provided in FIG. 5E . The internal pressure builds as the pulse enters the tapered section. The peak pressure occurs at the moment that the pulse reaches the exit of the nozzle. The peak internal pressure is less than 1 GPa (145,000 psi) which is within the capacity of the nozzle materials available. In a preferred embodiment of the invention, the nozzle comprises a carbide inner section that is pressed into a sleeve to provide a preload on the carbide. Those skilled in the art will understand that a composite nozzle of this type provides higher internal pressure capacity than a monobloc nozzle.
[0043] The cross-sectional area of the tapered nozzle section 132 is denoted as A(x), and it decreases exponentially along the length of the tapered nozzle section 132 , which is denoted as x. The relationship between the length and cross-sectional area of the tapered nozzle section 132 is shown according to the following exponential equation:
[0000]
A
(
x
)
=
A
i
exp
(
-
x
ln
(
R
)
l
t
)
[0000] In this equation, R is the inlet/outlet area ratio; and I t is the total length of the tapered nozzle section 132 . An example of a nozzle profile is as shown in FIG. 5D , which is derived from the data in the following Table 1.
[0000]
Length, in.
Diameter, in.
Straight
20
0.500
Taper
0
0.500
2
0.429
4
0.369
6
0.316
8
0.272
10
0.233
12
0.200
[0044] An exponential tapering is used for the tapered nozzle section 132 , as opposed to a linear tapering, to prevent the tapered section from being blown off from the pressure release during a firing. An external nut may be used to clamp the tapered nozzle section 132 to the straight nozzle section 120 . This nut may be attached with a torque of about 2000 ft-lbf. Based on the configuration of the straight nozzle section 120 and tapered nozzle section 132 , a water cannon may be converted into the hyper-pressure water cannon 100 suitable for use in excavation applications.
[0045] Although the concepts disclosed herein have been described in connection with the preferred form of practicing them and modifications thereto, those of ordinary skill in the art will understand that many other modifications can be made thereto. Accordingly, it is not intended that the scope of these concepts in any way be limited by the above description. | A hyper-pressure water cannon, or pulse excavator, is able to discharge fluid pulses at extremely high velocities to fracture a rock face in excavation applications. A compressed water cannon can be used to generate hyper-pressure pulses by discharging the pulse into a straight nozzle section which leads to a convergent tapered nozzle. The hyper-pressure water cannon design is relatively compact, and the pulse generator can readily be maneuvered to cover the face of an excavation as part of a mobile mining system. | 4 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to a transflective LCD device, more particularly to a transflective LCD device using different common voltages in the transmissive and reflective regions to present the same gray scale performance on the transmissive and reflective regions.
[0003] 2. Description of the Prior Art
[0004] A color liquid crystal display (LCD) panel comprises two transparent substrates and a liquid crystal layer interposed therebetween. Normally, the commonly used liquid crystal of the TFT LCD device is TN (Twisted nematic) liquid crystal, which is nematic. The liquid crystal molecules are arranged with regularity in one-dimension. All the long axes of the clubbed liquid crystal molecules are correlatively arranged in parallel according to a specific direction. The nematic liquid crystal easily flows due to its low viscosity because this molecule easily flows along the direction of its long axis.
[0005] As the structure of liquid crystal molecule is anisotropic, the induced photo-electronic effect will differ according to its arranging direction. In other words, the photo-electronic properties of liquid crystal molecule such as the dielectric permittivity or the refractive constant are anisotropic, too. Thus, the different gray scales displayed on the LCD can be formed by using the above matters to change the intensity of the incident light. For example, the dielectric permittivity can be divided into two vectors: ε∥ (in parallel with the long axis of liquid crystal molecule)and ε⊥ (vertical to the long axis of liquid crystal molecule). If ε∥>ε⊥, the dielectric anisotropy of the liquid crystal is called as positive and If ε∥<ε⊥, the dielectric anisotropy of the liquid crystal is called as negative. When a voltage is applied on the liquid crystal molecule, which will rotate parallel to or vertical to the electric field due to the positive or negative value of the dielectric anisotropy for permitting the light rays to pass through the liquid crystal or not. Now, the dielectric anisotropy of the TN type liquid crystal used in the TFT-LCD is almost positive.
[0006] FIG. 1A shows the arrangement of the positive type liquid crystal that is not applied the voltage. Presently, the pixel electrode 12 and the common electrode 13 are not applied voltage or the voltage difference on the liquid crystal layer 11 is zero so that the liquid crystal molecules 14 are arranged parallel to each other. Thus, the light can passes through not only the transmissive region but also the reflective region so as to be displayed on the screen of LCD. On the contrary, when a voltage is applied to the liquid crystal layer 11 , the liquid crystal molecules 14 begin to rotate and are not arranged parallel to each other. Then the liquid crystal molecules 14 will arrange vertically to the pixel electrode 12 and the common electrode 13 until the voltage achieves a specific value V 1 as shown in FIG. 1B . Thus, the light cannot pass through not only the transmissive region but also the reflective region, so it cannot be displayed on the screen of LCD.
[0007] FIG. 2A shows a transmissive rate to applied voltage curve (T-V Curve )and a refractive rate to applied voltage curve (R-V Curve). As shown in FIG. 2A , we can understand that the transmissive rate or the refractive rate is decreased while the applied voltage is increased. Therefore, the intensity of incident light rays can be varied by means of the above properties in order to display different gray scales on the screen of LCD. The conventional transflective liquid crystal display device is described with reference to FIG. 2B . The pixel electrode comprises a transmissive electrode 21 and a reflective electrode 22 that are connected electrically each other. The common electrode 23 is a transparent conductive layer formed in the transmissive and reflective regions. When a voltage is applied to the pixel electrode and the common electrode, the external voltage applied in the transmissive region is the same as that in the reflective region. As the T-V curve does not overlap the R-V curve as shown in FIG. 2A , the measured transmissive rate and the reflective rate are different when a fixed applied voltage is provided. It causes the gray scale displayed in the transmissive region is different from the gray scale displayed in the reflective region. In other words, the gray scale displayed on the screen of LCD by interior light source through the transmissive region (transmissive mode) is different from the gray scale displayed on the screen of LCD by exterior light source through reflective region (reflective mode). For example, the, LCD presents blue under transmissive mode, while the LCD presents pale blue under reflective mode. The users will query the quality of the product.
SUMMARY OF THE INVENTION
[0008] In the light of the state of the art described above, it is an object of the present invention to provide a transflective LCD device which is immune to the problems of the conventional transflective LCD device described above.
[0009] It is another object of this invention to provide a transflective LCD device using different common voltages in the transmissive and reflective regions to present the same gray scale performance on the transmissive and reflective regions.
[0010] In view of the above and other objects which will become apparent as the description proceeds, there is provided according to a general aspect of the present invention A liquid crystal display device which comprises a first substrate including a plurality of transmissive regions and a plurality of reflective regions; a transmissive electrode formed on at lest one of the said transmission regions; a reflective electrode formed on at least one of the said reflective regions and connected electrically with said transmissive electrode; a second substrate including a plurality of first common electrodes and a plurality of second common electrodes, wherein said first common electrodes are formed over said transmissive regions, said second common electrodes are formed over said reflective regions, and said first common electrodes are not connected electrically with said second common electrodes; and a liquid crystal layer interposed between said first substrate and said second substrate.
[0011] Base on the idea described above, wherein said first and second substrates are transparent.
[0012] Base on the aforementioned idea, wherein said transmissive electrode is a transparent conductive layer.
[0013] Base on the idea described above, wherein said transparent conductive layer is selected from the group consisting of ITO and IZO.
[0014] Base on the aforementioned idea, wherein said reflective electrode is a metal layer.
[0015] Base on the idea described above, wherein said metal layer is selected from the group consisting of Al, Ag, and AlNd.
[0016] Base on the idea described above, wherein said first and second common electrodes are transparent conductive layers.
[0017] Base on the aforementioned idea, wherein said transparent conductive layer is selected from the group consisting of ITO and IZO.
[0018] Base on the idea described above, wherein the distance between said first common electrode and said second substrate is equal to the distance between said second common electrode and said second substrate.
[0019] Base on the aforementioned idea, wherein the distance between said first common electrode and said second substrate is shorter than the distance between said second common electrode and said second substrate.
[0020] Base on the idea described above, wherein the distance between said first common electrode and said second substrate is longer than the distance between said second common electrode and said second substrate.
[0021] In view of the above and other objects which will become apparent as the description proceeds, there is provided according to a general aspect of the present invention A liquid crystal display device which comprises a first substrate including a plurality of transmissive regions and a plurality of reflective regions; a transmissive electrode formed on at least one of the said transmission regions; a reflective electrode formed on at least one of the said reflective regions and connected electrically with said transmissive electrode; a second substrate including a plurality of first common electrode regions and a plurality of second common electrode regions, wherein said first common electrode regions are formed over said transmissive regions, and said second common electrode regions are formed over said reflective regions; a first common electrode formed over said first and second common electrode regions; a second common electrode formed over said second common electrode regions and isolated from said first common electrode by a dielectric layer; and a liquid crystal layer interposed between said first substrate and said second substrate.
[0022] Base on the idea described above, wherein said first and second substrates are transparent.
[0023] Base on the aforementioned idea, wherein said transmissive electrode is a transparent conductive layer.
[0024] Base on the idea described above, wherein said transparent conductive layer is selected from the group consisting of ITO and IZO.
[0025] Base on the aforementioned idea, wherein said reflective electrode is a metal layer.
[0026] Base on the idea described above, wherein said metal layer is selected from the group consisting of Al, Ag, and AlNd.
[0027] Based on the idea described above, wherein said first and second common electrodes are transparent conductive layers.
[0028] Based on the aforementioned idea, wherein said transparent conductive layer is selected from the group consisting of ITO and IZO.
[0029] In view of the above and other objects which will become apparent as the description proceeds, there is provided according to a general aspect of the present invention A liquid crystal display device which comprises a first substrate including a plurality of transmissive regions and a plurality of reflective regions; a transmissive electrode formed on at least one of the said transmission regions; a reflective electrode formed on at least one of the said reflective regions and connected electrically with said transmissive electrode; a second substrate including a plurality of first common electrode regions and a plurality of second common electrode regions, wherein said first common electrode regions are formed over said transmissive regions, and said second common electrode regions are formed over said reflective regions; a first common electrode formed over said first and second common electrode regions; a second common electrode formed over said first common electrode regions and isolated from said first common electrode by a dielectric layer; and a liquid crystal layer interposed between said first substrate and said second substrate.
[0030] Based on the idea described above, wherein said first and second substrates are transparent.
[0031] Based on the aforementioned idea, wherein said transmissive electrode is a transparent conductive layer.
[0032] Based on the idea described above, wherein said transparent conductive layer is selected from the group consisting of ITO and IZO.
[0033] Based on the aforementioned idea, wherein said reflective electrode is a metal layer.
[0034] Based on the idea described above, wherein said metal layer is selected from the group consisting of Al, Ag, and AlNd.
[0035] Based on the idea described above, wherein said first and second common electrodes are transparent conductive layers.
[0036] Based on the aforementioned idea, wherein said transparent conductive layer is selected from the group consisting of ITO and IZO.
BRIEF DESCRIPTION OF THE DRAWINGS
[0037] The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same becomes better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:
[0038] FIG. 1A shows the arrangement of positive type liquid crystal that is not applied the voltage;
[0039] FIG. 1B shows the arrangement of positive type liquid crystal that is applied the voltage V 1 ;
[0040] FIG. 2A shows the figure of transmissive and reflective rates of liquid crystal that is applied the voltage;
[0041] FIG. 2B schematically illustrates a cross-sectional view of conventional transflective liquid crystal display device;
[0042] FIG. 3 schematically illustrates a cross-sectional view of transflective liquid crystal display device according to the first embodiment of the present invention;
[0043] FIG. 4 schematically illustrates a cross-sectional view of transflective liquid crystal display device according to the second embodiment of the present invention;
[0044] FIG. 5 schematically illustrates a cross-sectional view of transflective liquid crystal display device according to the third embodiment of the present invention;
[0045] FIG. 6 schematically illustrates a cross-sectional view of transflective liquid crystal display device according to the fourth embodiment of the present invention; and
[0046] FIG. 7 schematically illustrates a cross-sectional view of transflective liquid crystal display device according to the fifth embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0047] Some sample embodiments of the present invention will now be described in greater detail. Nevertheless, it should be recognized that the present invention can be practiced in a wide range of other embodiments besides those explicitly described, and the scope of the present invention is expressly not limited except as specified in the accompanying claims.
[0048] Please refer to FIG. 3 , a cross-sectional view of transflective liquid crystal display (LCD) device according to the first embodiment of the present invention is shown. Each pixel of the transflective LCD device can be divided into the transmissive region II and the reflective region I. The process of manufacturing the device will be described. First, a thin film transistor (TFT) 31 and a transparent dielectric layer 321 are sequentially formed on the transparent substrate 301 . The transparent dielectric layer 321 can be a silicon oxide (SiO x ) layer, a silicon nitride (SiN x ) layer, or their stacked layers. Subsequently, a pad dielectric layer 322 with bumps is formed on the surface of reflective region I. The pad dielectric layer 322 can be photosensitive resin or other dielectric materials. When the material of pad dielectric layer 322 is photosensitive resin, it can be directly coated on the transparent substrate 301 , then the transmissive region II and the reflective region I are patterned with the photolithography process. Then, the transmissive electrode 34 in the transmission electrode region II can be formed with ITO or IZO by the sputtering process. Similarly, the reflective electrode 33 in the reflection electrode region I can be formed with Al, Ag, or AlNd by the sputtering process. As mentioned above, the transmissive electrode 34 and the reflective electrode 33 are electrically connected each other for forming a pixel electrode. Besides, the pixel electrode is electrically connected with the TFT 31 .
[0049] After the color filter 35 formed on the transparent substrate 302 , a reflective common electrode 36 in the reflective region I and a transmissive common electrode 37 in the transmissive region II are formed. First, an ITO or IZO layer is coated on the color filter 35 with the sputtering process, and then the ITO or IZO layer are patterned and isolated by the photolithography and etching processes to form the reflective and transmissive common electrodes 36 , 37 that are not connected electrically each other. Finally, the transparent substrate 301 and the transparent substrate 302 are sealed with electrodes 33 , 34 , 36 , 37 face to face and vacuumed, and liquid crystal is injected into the space between the transparent substrate 301 , 302 to form a liquid crystal layer 39 . Hence, we can apply the different voltages to the reflective common electrode 36 in the reflective region I and the transmissive common electrode 37 in the transmissive region II in order to achieve a perfect gray scale presented on the screen of transflective LCD device.
[0050] Please refer to FIG. 4 , a cross-sectional view of transflective liquid crystal display (LCD) device according to the second embodiment of the present invention is shown. Each pixel of the transflective LCD device can be divided into the transmissive region II and the reflective region I. The process of manufacturing the device will be described. First, a thin film transistor (TFT) 41 and a transparent dielectric layer 421 are sequentially formed on the transparent substrate 401 . The transparent dielectric layer 421 can be a silicon oxide (SiO x ) layer, a silicon nitride (SiN x ) layer, or their stacked layers. Subsequently, a pad dielectric layer 422 with bumps is formed on the surface of reflective region I. The pad dielectric layer 422 can be photosensitive resin or other dielectric materials. When the material of pad dielectric layer 422 is photosensitive resin, it can be directly coated on the transparent substrate 401 , then the transmissive region II and the reflective region I are patterned with the photolithography process. Then, the transmissive electrode 44 in the transmission electrode region II can be formed with ITO or IZO by the sputtering process. Similarly, the reflective electrode 43 in the reflection electrode region I can be formed with Al, Ag, or AlNd by the sputtering process. As mentioned above, the transmissive electrode 44 and the reflective electrode 43 are electrically connected each other for forming a pixel electrode. Besides, the pixel electrode is electrically connected with the TFT 41 .
[0051] After the color filter 45 formed on the transparent substrate 402 , a reflective common electrode 46 in the reflective region I and a transmissive common electrode 47 in the transmissive region II are formed. First, a transparent dielectric layer 48 is coated on the color filter 45 with the deposition process, and the transparent dielectric layer in the transmissive region II is removed by the photolithography and etching processes. Next, an ITO or IZO layer is coated with the sputtering process, and the ITO or IZO layer are patterned and isolated by the photolithography and etching processes to form the reflective and transmissive common electrodes 46 , 47 that are not connected electrically each other. Finally, the transparent substrate 401 and the transparent substrate 402 are sealed with electrodes 43 , 44 , 46 , 47 face to face and vacuumed, and liquid crystal is injected into the space between the transparent substrate 401 , 402 to form a liquid crystal layer 49 . Hence, we can apply the different voltages to the reflective common electrode 46 on the reflective region I and the transmissive common electrode 47 on the transmissive region II in order to achieve a perfect gray scale presented on the screen of transflective LCD device.
[0052] Please refer to FIG. 5 , a cross-sectional view of transflective liquid crystal display (LCD) device according to the third embodiment of the present invention is shown. Each pixel of the transflective LCD device can be divided into the transmissive region II and the reflective region I. The process of manufacturing the device will be described. First, a thin film transistor (TFT) 51 and a transparent dielectric layer 521 are sequentially formed on the transparent substrate 501 . The transparent dielectric layer 521 can be a silicon oxide (SiO x ) layer, a silicon nitride (SiN x ) layer, or their stacked layers. Subsequently, a pad dielectric layer 522 with bumps is formed on the surface of reflective region I. The pad dielectric layer 522 can be photosensitive resin or other dielectric materials. When the material of pad dielectric layer 522 is photosensitive resin, it can be directly coated on the transparent substrate 501 , then the transmissive region II and the reflective region I are patterned with the photolithography process. Then, the transmissive electrode 54 in the transmission electrode region II can be formed with ITO or IZO by the sputtering process. Similarly, the reflective electrode 53 in the reflection electrode region I can be formed with Al, Ag, or AlNd by the sputtering process. As mentioned above, the transmissive electrode 54 and the reflective electrode 53 are electrically connected each other for forming a pixel electrode. Besides, the pixel electrode is electrically connected with the TFT 51 .
[0053] After the color filter 55 formed on the transparent substrate 502 , a reflective common electrode 56 in the reflective region I and a transmissive common electrode 57 in the transmissive region II are formed. First, an ITO or IZO layer is coated on the color filter 55 with the sputtering process, a transparent dielectric layer 58 is coated on the ITO or IZO layer with the deposition process, and the transparent dielectric layer in the transmissive region II is removed by the photolithography and etching processes. Next, another ITO or IZO layer is coated with the sputtering process, and the ITO or IZO layer are patterned and isolated by the photolithography and etching processes to form the reflective and transmissive common electrodes 56 , 57 that are not connected electrically each other. Finally, the transparent substrate 501 and the transparent substrate 502 are sealed with electrodes 53 , 54 , 56 , 57 face to face and vacuumed, and liquid crystal is injected into the space between the transparent substrate 501 , 502 to form a liquid crystal layer 59 . Hence, we can apply the different voltages to the reflective common electrode 56 on the reflective region I and the transmissive common electrode 57 on the transmissive region II in order to achieve a perfect gray scale presented on the screen of transflective LCD device.
[0054] Please refer to FIG. 6 , a cross-sectional view of transflective liquid crystal display (LCD) device according to the fourth embodiment of the present invention is shown. Each pixel of the transflective LCD device can be divided into the transmissive region II and the reflective region I. The process of manufacturing the device will be described. First, a thin film transistor (TFT) 61 and a transparent dielectric layer 621 are sequentially formed on the transparent substrate 601 . The transparent dielectric layer 621 can be a silicon oxide (SiO x ) layer, a silicon nitride (SiN x ) layer, or their stacked layers. Subsequently, a pad dielectric layer 622 with bumps is formed on the surface of reflective region I. The pad dielectric layer 622 can be photosensitive resin or other dielectric materials. When the material of pad dielectric layer 622 is photosensitive resin, it can be directly coated on the transparent substrate 601 , then the transmissive region HI and the reflective region I are patterned with the photolithography process. Then, the transmissive electrode 64 in the transmission electrode region II can be formed with ITO or IZO by the sputtering process. Similarly, the reflective electrode 63 in the reflection electrode region I can be formed with Al, Ag, or AlNd by the sputtering process. As mentioned above, the transmissive electrode 64 and the reflective electrode 63 are electrically connected each other for forming a pixel electrode. Besides, the pixel electrode is electrically connected with the TFT 61 .
[0055] After the color filter 65 formed on the transparent substrate 602 , a reflective common electrode 66 in the reflective region I and a transmissive common electrode 67 in the transmissive region II are formed. First, a transparent dielectric layer 68 is coated on the color filter 65 with the deposition process, and the transparent dielectric layer in the reflective region I is removed by the photolithography and etching processes. Next, an ITO or IZO layer is coated with the sputtering process, and the ITO or IZO layer are patterned and isolated by the photolithography and etching processes to form the reflective and transmissive common electrodes 66 , 67 that are not connected electrically each other. Finally, the transparent substrate 601 and the transparent substrate 602 are sealed with electrodes 63 , 64 , 66 , 67 face to face and vacuumed, and liquid crystal is injected into the space between the transparent substrate 601 , 602 to form a liquid crystal layer 69 . Hence, we can apply the different voltages to the reflective common electrode 66 on the reflective region I and the transmissive common electrode 67 on the transmissive region II in order to achieve a perfect gray scale presented on the screen of transflective LCD device.
[0056] Please refer to FIG. 7 , a cross-sectional view of transflective liquid crystal display (LCD) device according to the fifth embodiment of the present invention is shown. Each pixel of the transflective LCD device can be divided into the transmissive region II and the reflective region I. The process of manufacturing the device will be described. First, a thin film transistor (TFT) 71 and a transparent dielectric layer 721 are sequentially formed on the transparent substrate 701 . The transparent dielectric layer 721 can be a silicon oxide (SiO x ) layer, a silicon nitride (SiN x ) layer, or their stacked layers. Subsequently, a pad dielectric layer 722 with bumps is formed on the surface of reflective region I. The pad dielectric layer 722 can be photosensitive resin or other dielectric materials. When the material of pad dielectric layer 722 is photosensitive resin, it can be directly coated on the transparent substrate 701 , then the transmissive region II and the reflective region I are patterned with the photolithography process. Then, the transmissive electrode 74 in the transmission electrode region II can be formed with ITO or IZO by the sputtering process. Similarly, the reflective electrode 73 in the reflection electrode region I can be formed with Al, Ag, or AlNd by the sputtering process. As mentioned above, the transmissive electrode 74 and the reflective electrode 73 are electrically connected each other for forming a pixel electrode. Besides, the pixel electrode is electrically connected with the TFT 71 .
[0057] After the color filter 75 formed on the transparent substrate 702 , a reflective common electrode 76 in the reflective region I and a transmissive common electrode 77 in the transmissive region II are formed. First, an ITO or IZO layer is coated on the color filter 75 with the sputtering process, a transparent dielectric layer 78 is coated on the ITO or IZO layer with the deposition process, and the transparent dielectric layer in the reflective region I is removed by the photolithography and etching processes. Next, another ITO or IZO layer is coated with the sputtering process, and the ITO or IZO layer are patterned and isolated by the photolithography and etching processes to form the reflective and transmissive common electrodes 76 , 77 that are not connected electrically each other. Finally, the transparent substrate 701 and the transparent substrate 702 are sealed with electrodes 73 , 74 , 76 , 77 face to face and vacuumed, and liquid crystal is injected into the space between the transparent substrate 701 , 702 to form a liquid crystal layer 79 . Hence, we can apply the different voltages to the reflective common electrode 76 on the reflective region I and the transmissive common electrode 77 on the transmissive region II in order to achieve a perfect gray scale presented on the screen of transflective LCD device.
[0058] Although the specific embodiment has been illustrated and described, it will be obvious to those skilled in the art that various modifications may be made without departing from what is intended to be limited solely by the appended claims. | This invention relates to a transflective LCD device using different common voltages in the transmissive and reflective regions to present the same gray scale performance on the transmissive and reflective regions. The liquid crystal display device includes a first substrate including a plurality of transmissive regions and a plurality of reflective regions; a transmissive electrode formed on said transmission electrode region; a reflective electrode formed on said reflective regions and connected electrically with said transmissive electrode; a second substrate including a plurality of first common electrodes and a plurality of second common electrodes, wherein said first common electrodes are formed over said transmissive regions, said second common electrodes are formed over said reflective regions, and said first common electrodes are not connected electrically with said second common electrodes; and a liquid crystal layer interposed between said first substrate and said second substrate. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This case is related to a co-pending application, U.S. Ser. No. 09/661,101 entitled “TERMINAL SERVER DATA FILE EXTRACTION AND ANALYSIS APPLICATION”, which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
In the situation involving networks where numerous client terminals are connected to a test server, it is desirable to obtain information as to the actual execution times for accessing programs, and also for example, accessing information about the time required for executing different parts of available programs.
Thus, a performance and measurement system for defining and measuring user-relevant response times to remote client stations which are serviced by a terminal server, is of great importance to evaluate the status of a network of users and terminal servers.
Performance data produced by the interaction of the client-users and the terminal server is collected and subsequently logged. Once the data is logged, the data may then be accessed and collected by an Administrator in order to evaluate the system responses involved in the network.
Performance tools are used to measure the performance of the test server in regard to its availability of servicing the various and multiple clients. A resultant state of the system may be accomplished in order to evaluate the total resource utilization of the system. Such a determination may eventually discover which resources cause slowdowns or bottlenecks in system performance, and once identified, these resources can be upgraded to improve system performance.
Another useful purpose for evaluating computer performance may be for what is called “application tuning” in order to focus on particular user applications or situations in order to determine how to improve system performance regarding a particular application.
Another use for performance tools is for the purpose of troubleshooting and to help determine why system performance may be degrading without any immediately apparent reason.
In many situations, so-called performance tools have generated too much information making it difficult for an operator-user to fully comprehend the nature of what is happening. If a system gathers and logs huge amounts of information, this requires large memory sources for data logging and is often very difficult to analyze, in addition to taking a lot of processing power to generate this information and then to try to present this data into a form that is useful to a user.
It is always a problem to identify when the performance of a system has been degraded beyond acceptable limitations. Many of the earlier attempts for such analysis provided only indirect information regarding the end-user's performance expectations in addition to requiring extraordinary administration and management efforts in the system to develop the required information. Many of the earlier systems were influenced by the test environment characteristics and did not provide feedback for the actual client sessions under test. As a result, this necessitated the opening of additional terminal server connections which were administratively time-consuming and caused significant additional CPU overhead.
FIG. 5 is an illustration of one type of earlier performance measurement which was only partially useful as it only provided very limited information regarding processor utilization which limited the user's ability to evaluate the conditions of operation.
The presently described system and method will be seen to measure and collect the response times for any variety of designated actions initiated by terminal server scripts. The method will be seen to call a timer utility before and after each designated action, such as logging on, opening applications, and typing of characters.
Then, by noting the response times involved during a sequence of different operating conditions (small number of concurrent client-users over to a large number of concurrent client-users) it is then possible to determine what are the acceptable and non-acceptable operating limits for the entire system.
SUMMARY OF THE INVENTION
In a system where multiple client-users are connected via hubs and switches to a back-end server, there is provided a method whereby a program is provided to measure, collect, and analyze the response times for any variety of designated actions initiated by terminal server scripts, and whereby the calling of a timer utility, before and after designated actions, will provide information on the resulting response times.
Because the timing components are added to existing client scripts, rather than adding new scripts, the timing components are minimally intrusive to the load on the server under test. The timing component provides data for all the sessions involved in any given test and the timer is integrated into sessions that are already part of the test environment.
Actions can be designated for measurement such that the resulting data can be analyzed and is directly relevant to the end-user's real world performance expectations. The resulting data is minimally influenced by any test environment characteristics. To achieve this, the administrator modifies existing scripts by adding commands that execute strictly on the Remote Client PC.
The accumulated response times are saved to the Client PC-User terminals.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a drawing of a system network showing multiple simulated clients connected through a switching device to a set of back-end servers, monitor and control servers, and a test server;
FIG. 2 is a sketch showing relationships between two typical Client-Personal Computers (x,y) in the multitude of Terminal Server Clients, as related to the Control Server and Test Server;
FIG. 3 is a flow chart showing the steps involved for executing applications on each simulated client;
FIG. 4 is a flow chart of the timer function program to calculate response times and record results on the timer log file;
FIG. 5 is a graph showing the number of simulated client users (G—G) while also indicating another graph (R—R) which shows the percent utilization of the total possible utilization for each point of the number of active Client-Users;
GLOSSARY OF RELEVANT TERMS
ACTION LABEL: An action label is a descriptive name that an administrator assigns to an action that he/she has decided to measure using the Terminal Server Simulated Client Performance Measurement Tool. On Table III of co-pending U.S. Ser. No. 09/661,101, there are six action labels for discreet actions that were designated within the TS Scripts for measurement. These action labels are: Connect, Excel, Outlook, Cmd Prompt, Explorer, and word.
BACK END SERVERS: Servers that form the infrastructure for the test environment. Various applications and user functionality is supported by these servers with the intent of modeling a real world environment. These include the Internet Information Server (IIS), the Primary Domain Controller (PDC), the Exchange Server, and File and Printer Server, plus a Monitor, Control and Test Server.
CLIENT SCRIPT: A looping list keyboard input that is fed from the TS (Terminal Server) Client Software to the Test Server in order to mimic real user input. The script sends the appropriate keyboard sequence to log into a Windows session, to open Excel, Outlook, Internet Explorer, Word, and perform common real world actions within each application (i.e., creating graphs, printing, sending email, browsing web pages). StartTimer and StopTimer calls before and after designated activities are inserted into these scripts.
CONTROL: Control Server station (CONTROL) controls the creation, distribution, and execution of the scripts. It also manages the remote Client PCs as they execute the scripts, and timer functions.
EXCHANGE: A server that hosts and allows email services.
GRAPHICAL UPDATE: When a user/or simulated user delivers some form of input (pressing the letter “k” on the keyboard) to a Terminal Server Client Session, the “k” input is first sent to the Terminal Server over the network. The Terminal Server decides what should happen when this “k” is input. If this “k” input changes what should be displayed on the screen of the Terminal Server Client Session, then the Terminal Server sends that graphical update over the network to the Client Session. If a text editor such as Microsoft Word was open when the “k” was submitted then the corresponding graphical update would add the letter “k” to the appropriate location on the Terminal Server Client window.
IIS: Internet Information Server. Hosts the internet sites that are browsed in the course of the Client Script loop.
LOG FILE: Synonymous with Timer Log File.
MONITOR: The monitor server station (MONITOR) captures all the Performance Monitor data from the test server, and stores the associated logs. This monitoring is done remotely in order to minimize the performance impact on the server under test.
PDC: Primary Domain Controller. This is the system that authenticates user logons for the entire testing domain including the TS Clients who attempt to gain access to the test server.
REMOTE CLIENT PC: A variety of desktop PCs can be used as a remote Client PC. This remote system runs the terminal server client (TS Client). These systems host the client component of the TS connection, the SM Client, and the log files.
SM CLIENT: (Simulated Client) The application which takes a client script and feeds it to the TS (Terminal Server) Client. This process occurs strictly on the remote client PC and therefore does not contribute to the load/stress on the test server.
TERMINAL SERVER CLIENT: A Terminal Server Client is an application that runs on a remote client PC. It receives desktop graphics from the test server and sends user initiated mouse movements and keyboard strokes to the test server.
TERMINAL SERVER EDITION: A special version of NT4 Microsoft Operating system that incorporates a multi-user kernel and allows numerous simultaneous client sessions. The Windows 2000 equivalent does not require a special edition of the operating system, but instead requires an additional “Terminal Services” component to be installed.
TERMINAL SERVICES: Although the process is virtually transparent to the user, terminal services gives remote users the capability to run the Windows desktop and applications from a central server. A small application, Terminal Server Client, is installed on the Remote Client PC. The Terminal Server Client sends mouse movements and keystrokes and receives the corresponding graphical updates from a central test server.
TEST SERVER: This server is the focus of the testing environment. It runs the Terminal Services enabling operating system (NT4 Server Terminal Server Edition, or Windows 2000 Server with Terminal Services component enabled). The test server receives mouse movements and keyboard input over the network sent from the TS (Terminal Server) Clients which are executing on the remote Client PC. The test server hosts the client desktops and applications, sending the resulting graphical updates to the TS Client. The test server is commonly referred to as a central server because it “centralizes” the execution of Windows desktops and applications similar to the way a mainframe works.
TIMER: A unit providing clock time in milliseconds with a resolution equal to the machine cycle speed.
TIMER DYNAMIC LIBRARY: A dynamic linked library piece of the WTS Timer Utility containing multiple programmatic procedures that can be called/initiated from another file. The Client Scripts are modified with calls to this library.
TIMER LIBRARY: Synonymous with Timer Dynamic Library.
TIMER LOG FILE: A file created during the execution of a timer modified Client script. This file details the results of the timing actions, with the name of the action measured, the time in milliseconds the action took to execute, and the time/date of the entry to the log file.
USER ID: Each TS (Terminal Server) Client has a unique identifier.
DESCRIPTION OF PREFERRED EMBODIMENT
FIG. 1 shows the general overall environment of modules and units which are involved in the computing architecture for a Thin-Client/Server set of installations. The test server 18 contains a terminal server enabled operating system (NT 4 Terminal Server Edition or Windows 2000 Server with Terminal Services enabled). Terminal Services functionality is made possible using three components which are (i) the Terminal Server Operating System, (ii) the Remote Desktop Protocol, and (iii) Terminal Server Client. With the addition of the SM Client ( 10 xsm , FIG. 2) and test script ( 16 ts , FIG. 2) components imaginary users can be created to simulate the work load of real users.
As seen in FIG. 1, there is indicated a PC farm designated as Terminal Server Edition Clients 10 . Here there is indicated eight groups of PC's designated 10 a , 10 b . . . thru 10 g , 10 h . Each item represents a group of 15. Each group of PCs are connected through a 100 megabit HUB designed as 9 a , 9 b , . . . 9 g , 9 h . Also the series of HUBs are connected to a 100 megabit switch 12 .
The Terminal Server client software in FIG. 2 ( 10 xtsc , 10 ytsc ) runs on a range of devices with varying operating systems and enables the users to gain seamless access to 32-bit applications. The Remote Desktop Protocol (RDP) is used to communicate between the client PCs 10 and the test server 18 . This component involves a network protocol that connects the client PCs and the test server over the network.
As will be seen in FIG. 1, the testing environment is equipped with 8 sets of 15 PCs 10 a , 10 b , . . . 10 g , 10 h . With, for example, 120 total PCs, each running one set of Terminal Server client connections, the testing environment can simulate 120 user connections to the test server 18 . While each PC (in the Client Group 10 ) is capable of running multiple Terminal Server connections.
It is important to know the performance and load capabilities for the Terminal Services Operating System, which is installed on test servers, shown as item 18 in FIG. 1 . Here this is of considerable value in order to enable designers to plan and size the deployment of Thin-Client/Server Solutions.
The test server 18 of FIG. 1 is designed to deliver reliable performance and scalability to as many Terminal Server Clients 10 as possible without sacrificing optimal performance. A concept of “optimal performance” is defined as a performance that allows the Thin-Client architecture to remain transparent to the user.
In FIG. 1 the Test Server 18 is set up as a test server for running either the Microsoft Windows NT Server 4.0 Terminal Server Edition or Windows 2000 Server with Terminal Services enabled, and is configured with the Office 2000 Suite of applications. The test network of FIG. 1 also provides a monitor ( 16 m ) and control ( 16 c ) of station 16 . The monitor station ( 16 m ) captures all the performance monitor data concerning the test server ( 18 ) and stores the associated logs. This monitoring is done remotely in order to minimize the performance impact on the server 18 under test.
The control station in 16 controls the creation, distribution, and execution of the scripts. It also manages the remote clients 10 as they execute the scripts. The Monitor-Control servers 16 and Test Server 18 are seen connected to the 100 megabit switch 12 .
Now, additionally connected to the 100 megabit switch 12 is a set of Backend Servers 14 which are set up to simulate a real-world environment. These include a Primary Domain Controller (PDC), a Microsoft Exchange Server 5.5 (EXCHANGE), a Microsoft Internet Information Server 4.0 (IIS), and a Microsoft Windows NT server 4.0, used for file and printer sharing (FILE&PRINT).
BENCHMARK PROCEDURES: Experimental operations indicated that “simulated” Office 2000 user scripts would take approximately thirty minutes to loop through Outlook, Word, Access, Excel, and Internet Explorer 5 at a typing speed of forty-eight words per minute. These scripts are designed to match the typical work patterns of real-world users. Tests were made to stress the server under test 18 by logging on simulated Terminal Server clients that were running on these scripts.
The number of concurrent clients was gradually increased while the scripts were cycled through the various applications. Thus multiple test runs were conducted and additional sets of Performance Monitor (PERFMON) log files were produced to verify reproducibility.
BENCHMARK MEASUREMENTS: Using the Microsoft Performance Monitor, performance counters were collected on all the available objects and counters. The counters for Processor Usage, Active Sessions, and Processor Queue Length are activated and a recording is made for percent of total processor usage for each period related to the number of active session Client-users. The performance data thus reflects the stress on the server 18 under test which influences the end-user performance. This is indicated in FIG. 5 .
To evaluate end-user performance, timer components are inserted into the test scripts before and after a designated action. For example, timed actions can include (i) log-on time “Connect”; (ii) time to open applications and (iii) character delay while typing.
DEFINING OPTIMAL PERFORMANCE: Optimal performance is the point at which a server is loaded with the maximum number of clients possible without user performance degrading beyond a predetermined limitation. During testing, timer logs are created to measure the delays for completing certain actions from the user's point of view. Ideally, the limitations on delays are determined with the intent of providing a transparent solution to the user, that is to say so that the user could not distinguish that the applications are running on a centralized server, such as server 18 .
Table I below is a table showing one possible configuration for a test server undergoing tests. (this is just one possible server configuration) (Test Server 18 ).
TABLE I
Table I Server Test Configuration
System
Processor
Cache
Memory
Disk
Network
Col. 1
Col. 2
Col. 3
Col. 4
Col. 5
Col. 6
ES2045
Four Intel
L2 Cache:
2 GB
External
One Network
Xeon
2 MB per
Memory
disk array
Interface Card
processors
processor
with 100 MB
at 550
access
Mhz
The first column shows the system designation while the second column shows the processors involved as four Intel XEON processors. Column 3 indicates the cache as a L2 Cache, having two megabytes per processor. Column 4 shows the memory utilized as being 2 gigabytes of memory. Column 5 shows the disk as being an external disk array, while column 6 shows the network as involving one network interface card with one hundred megabytes of access.
In order to determine the optimal performance of a terminal server solution, it is required that Test Server 18 be placed under a significant load using Thin-Client simulation. Microsoft provides a scripting engine and language to be used for such testing (the SM Client and associated Testing Scripts). So, in order to “simulate” user operations, there are virtual Thin-Clients which are launched and there are user applications applied within the given session. Then realistic user scenarios are constructed by combining both application and task sequences in the scripts.
The Office 2000 user simulation script was developed for measuring the performance of Office 2000 in a Terminal Server environment. By modifying the scripts to time record the desired actions, the Terminal Server Client Measurement Tool measures and saves data regarding the delays involved in executing these actions.
FIG. 2 is a sketch illustrating the inter-relationships of modules involved in the simulated Client process. Assuming for example, that there are 120 clients as was indicated in FIG. 1, then a typical Client PC-X shows a block designated 10 x which indicates several sets of software which reside in Client 10 x . One portion of software is designated Terminal Server Client (TS Client) 10 xtsc . This piece of software receives information from another set of software designated SM Client, 10 xsm.
Likewise, another Personal Computer designated as another typical Client PC-Y is another typical PC residing in the overall farm of 120 PCs. This client is designated 10 y . Again, there are two distinct groups of software in the Client Y and these are designated as the Terminal Server Client (TS Client) 10 ytsc , which is fed from the package of software designated SM Client 10 ysm.
As will be further seen in FIG. 2, there is a Control Server 16 which utilizes a Test Script portion of software designated 16 ts . This test script is fed to each of the SM (Simulated) Clients in the Client farm and, in this case, FIG. 2 shows the test script being transmitted to the SM Client 10 xsm and also to the SM Client 10 ysm . Thus, the test scripts in the Control Server 16 are fed to the software of the SM Client software for each and every one of the PCs. Subsequently then, the SM Client software is then fed to the Terminal Server Client software in each one of the various PCs in the farm 10 .
Connected from the Client-PC 10 x , it will be seen that each keyboard stroke is provided from the TS Client 10 xtsc over to the Client X Space 18 x , and the Client X Space 18 x feeds back the corresponding graphical update information to the TS Client 10 xtsc.
Likewise, in the other typical Client PC-Y, designated 10 y , the TS Client 10 ytsc will feed an enumeration of keyboard strokes over to the Client Y Space designated 18 y , and the Client Y will feed back the corresponding graphical updates back to the TS Client 10 ytsc . The Client X Space 18 x and the Client Y Space 18 y , which is typical of spaces provided for each and every one of all of the active TS Client sessions, are all located in the test server 18 .
A flowchart for the simulated client execution operations is shown in FIG. 3 . This flow will occur for each and every one of the simulated clients 10 a , 10 b , 10 c , . . . 10 f , 10 g.
At step A 1 , there is the initiation or start of the SM Client software, such as 10 xsm , and 10 ysm , etc., (FIG. 2) which will then look for a specific test script for each and every one of the multiple client PCs.
Then, at step A 2 , there is an importation of the test script from the control server 16 over to each of the various SM Clients, such as 10 xsm , 10 ysm , etc.
At step A 3 , there is an initialization of the timer function which will be later seen in FIG. 4 .
Step A 4 of FIG. 3, is a multiple decision block from where the process sequence can go to—Exit, A 4 E); to step A 5 (B); to step A 6 (C); to step A 7 (wait for graphical update) or step A 8 (execute keystroke command).
At step A 4 of FIG. 3, there will be initiated the reading of the next script command from the Control Server 16 where the Terminal Server (TS) client is turned on, followed by a simulated user log-on where the Simulated Client (SM client) application provides a user-name and password.
As the commands are fed from the Simulated Client to Terminal Server Client, the TS Client ( 10 x ) ( 10 y ) sends a series of keystrokes to the client space (such as 18 x , 18 y of FIG. 2) in the Test Server 18 . After this, at the same time, there will be a “start” of the timer command at step A 5 , FIG. 3, which indicates the marker B continuing to FIG. 4 for the timer function operation.
Simultaneously at step A 7 , a Wait command is initiated in order to receive a specified graphical update which was seen in the earlier FIG. 2, whereby the Client X Space, 18 x , provides a graphical update to the TS Client, 10 xtsc , and also the Client Y Space, 18 y , provides the graphical updates to the TS Client 10 ytsc.
After the graphical update has been completed, there is initiated at Step A 6 , the “Stop Timer” command which is later seen in its operative steps through reference marker C onto the timer function program of FIG. 4 .
At step A 8 , there is an execution of the script command which when executed, will return back to step A 4 in order to read the next script command.
The script commands will continue to be read until an “End Test” command is encountered and the program will exit at step A 4 E.
Now referring to FIG. 4, there is seen the timer function program which has been initiated at step B from FIG. 3, and at step C from FIG. 3 . The purpose here is to measure the time period involved between the request for an action and the graphical update indicating the complete execution of that desired action. Now referring to reference marker B, the first step at step B 1 is the start of the timer function which collects the current time from the Remote Client PC.
At step B 2 , a decision block is utilized to question whether the timer log file is open or not. If the log file is not open (NO), then the sequence proceeds to step B 3 to open the log file. Likewise, if the log file is open (YES) at step B 2 , then the sequence proceeds to step B 4 so that the start data (the date and time in milliseconds) can be cached, placing the time therein when the process started, into cache memory.
Then continuing on with FIG. 4 at the reference marker C (from FIG. 3) where at step C 1 there is a stop action for the timer function which collects the current time at that instant. Next, at step C 2 a calculation is made of the response time for that particular action for that particular TS Client Session, by calculating the difference between the stop time and cached “start time” which is referred to as the “response time”. The process then continues by obtaining the action label, user ID and response time for that particular PC client, and this information at step C 5 , is placed into the timer log file of FIG. 4 .
As was indicated in FIG. 3, the start and the stop timer functions are called for in every single designated action performed within the simulated client script for each and every single one of the multiple number of TS Client sessions. Therefore, an entry is made to the log file for every single designated script action for each and every one of the TS Client sessions.
FIG. 5 is an illustration of a prior art type of graphical analysis which was derived in the Windows Operating System and illustrates the limited information available in contrast to the greater amount of specific information available in the presently described performance measurement tool. Here, only a few limited varieties of information will be available since such a prior art system only showed utilization and number of active users.
In the present enhanced performance tool, it is now possible to view the test server 18 to see what the client users are getting in their simulated operations which information is all logged into the Timer Log File.
Thus, the present system captures log-on time, time to access an application and other specific details regarding each client-user that was previously not available in such graphs as that shown in FIG. 5 .
The timer Log information in the present application can be printed out and also displayed in graphical format as is illustrated in the co-pending application, U.S. Ser. No. 09/661,101 entitled “Terminal Server Data File Extraction and Analysis Application”. The Y axis or ordinate of FIG. 5, shows the number of active users which ranges in this case on the graph from 0 to 200 users. The X axis or abscissa, is an illustration of the percentage of total possible processor utilization that is operative related to the number of active users.
Observation of FIG. 5 will indicate the graph line G—G, which shows the number of users in active sessions at any given moment of time.
The graph line shown as R—R is an illustration of the percentage of total processor utilization that is occurring at each quantity of concurrent users. Thus, for example, when there are 112 Users, then it will be seen that the percentage utilization is 40%. Likewise, when there are 136 Users, then the percentage utilization is approximately 50%. The vertical markings on the graph R—R show that a reading has occurred at 15 second intervals, thus a period of 15 seconds has transpired through each of the vertical markers. This interval period of course, can be either increased or decreased, as necessary.
Thus, by observing this graph of FIG. 5, the amount of processor utilization can be viewed with respect to the number of Users in active sessions utilizing the Client PCs running simulated scripts. Thus one can see the approximate efficiency of the Terminal Server under each different set of operating conditions.
In the presently described enhanced performance tool, upon the completion of a test run, an Administrator can peruse the timer logs to determine the point at which the Test Server 18 failed to provide an acceptable end-user experience. The Administrator can determine this point by applying rules in regard to the maximum time a designated action can take. For example, An Administrator might establish 5,000 milliseconds as a limitation beyond which performance is determined to be non-optimal. Given that the test procedures gradually add client sessions on to the Test Server 18 , the optimal performance will be found at the point where the last user initiates an action without exceeding this established limitation.
The method for performance test monitoring and analysis is seen to basically involve a series of steps which were shown in the attached drawings of FIGS. 3 and 4. A WTS (Windows Terminal Server) timer utility was illustrated in a series of steps in FIGS. 3 and 4.
Thus there has been shown the process of measuring response times for a variety of actions on a multiple number and expanding numbers of simulated clients. This process is designed to occur for each simulated client that connects to a Terminal Server using a test script modified with the Timer component functions.
Described herein has been a performance measuring method for enabling one to observe the overall operation of a terminal server solution which services multiple Client-Users. A simulated script is run on each Client-User and overall observations are made as to response time during different periods of operating conditions with variable numbers of concurrent Client-Users. From this observation, a designer or Administrator can configure the solution so that the system will only operate during optimal conditions and will not degrade into a non-allowable or non-acceptable operating situation.
While other embodiments of such performance methods may be implemented, the invention will be seen to be defined by the attached claims. | A performance measurement tool is developed to measure performance of a terminal server servicing multiple Clients who operate on remote systems in a farm of multiple PC's. Test scripts to simulate actual operating conditions are run on each PC Client-User over a sequence of time which varies the number of concurrently active PC Client-Users from a small number of Users to a vary large number of current Users. During this test period, a record is kept of designated simulated-user-initiated actions such as log-on times, time to open various application programs, and character entries thus to determine acceptable operating configurations. | 6 |
FIELD OF THE INVENTION
[0001] The present invention relates to a method for forming a plug in a semiconductor device; and, more particularly, to a method for forming a landing plug in a semiconductor device through the use of a selective epitaxial growth (SEG) technique.
DESCRIPTION OF RELATED ARTS
[0002] As a semiconductor device gets highly integrated, it is required to develop a metal-oxide semiconductor field effect transistor (MOSFET) of which gate length is below about 0.1 μm. Also, a height of a capacitor increases to above about 1 μm to secure a sufficient capacitance within a limited narrow area. This increased capacitor height further results in an increase of a depth of a contact hole formed for a contact between a storage node contact of the capacitor and a wiring. For this reason, a landing plug typically having a structure of ploy plug pad (PPP) is used to form such contact.
[0003] Referring to FIGS. 1A to 1 D, there is described a convention method for forming a landing plug to which the PPP structure is applied.
[0004] Referring to FIG. 1A, a gate insulation layer 12 is formed on a semiconductor device providing a device isolation layer 11 with a shallow trench isolation structure, and a polysilicon layer 13 and a metal layer 14 are sequentially formed thereon. Then, a hard mask 15 is formed on the metal layer 14 . With use of the hard mask 15 , the metal layer 14 and the polysilicon layer 13 are etched so to form a gate 100 . An insulation layer is deposited on an entire surface of the substrate 10 and proceeded with a blanket etch process so that a spacer 16 is formed at lateral sides of the hard mask 15 and the gate 100 .
[0005] Referring to FIG. 1B, an inter-layer insulation layer 17 is deposited on the above entire surface of the substrate 10 so as to fill a space between the spacers 16 . The substrate 10 is then etched to expose a surface of the hard mask 15 and is planarized by performing a chemical mechanical polishing (CMP) process thereto. Afterwards, the inter-layer insulation layer 17 is etched to expose a partial portion of the substrate 10 disposed between the spacers 16 , whereby a contact hole 18 is formed.
[0006] Referring to FIG. 1C, a polysilicon layer 19 is deposited on the inter-layer insulation layer 17 to be buried in the contact hole 18 . As shown in FIG. 1D, the polysilicon layer 19 is entirely etched to expose surfaces of the hard mask 15 and the inter-layer insulation layer 17 through a CMP process. As a result, a landing plug 19 A with the PPP structure is formed.
[0007] However, it is difficult to obtain a low resistance with use of the landing plug having the PPP structure owing to a fact that a contact area gets largely decreased as a semiconductor device is highly integrated. Therefore, instead of using the PPP structure, a selective epitaxial growth (SEG) technique is currently applied for selectively growing silicon within the contact to form a landing plug. This recent application of the SEG technique allows the landing plug to have a low resistance and simplifies subsequently performed processes since it is possible to eliminate such process as the CMP. Also, since silicon is selectively grown on the contact portion, this SEG technique does not have a gap-fill problem even if the contact hole is deep.
[0008] However, the SEG technique has a limitation to decrease the resistance up to a certain point. For instance, in case of a next generation semiconductor device of which gate length is below about 0.1 μm, it is difficult to secure a sufficiently low resistance suitable for such semiconductor device. A device operation speed is reduced due to a resistance-capacitance delay, thereby being unable to meet the demands of high-integration and high-speed in a semiconductor device.
SUMMARY OF THE INVENTION
[0009] It is, therefore, an object of the present invention to provide a method for forming a landing plug in a semiconductor device capable of securing a sufficiently low resistance corresponding to demands of high-integration and high-speed by applying a selective epitaxial growth (SEG) technique.
[0010] In accordance with an aspect of the present invention, there is provided a method for forming a landing plug, including the steps of: forming an inter-layer insulation layer on a substrate; forming a contact hole by etching the inter-layer insulation layer until exposing a partial portion of the substrate; forming a first conductive layer with a predetermined thickness inside of the contact hole, the first conductive layer being made of a silicon layer; forming a second conductive layer on the inter-layer insulation layer in such a manner of being buried into the contact hole in which the silicon layer is formed; and performing a blanket etch process to the second conductive layer until exposing surfaces of the inter-layer insulation layer and the hard mask so that a landing plug is formed.
BRIEF DESCRIPTION OF THE DRAWINGS(S)
[0011] The above and other objects and features of the present invention will become apparent from the following description of the preferred embodiments given in conjunction with the accompanying drawings, in which:
[0012] [0012]FIGS. 1A to 1 D are cross-sectional views illustrating a conventional method for forming a landing plug in a semiconductor device;
[0013] [0013]FIGS. 2A to 2 E are cross-sectional views illustrating a method for forming a landing plug in a semiconductor device in accordance with a first preferred embodiment of the present invention; and
[0014] [0014]FIGS. 3A to 3 E are cross-sectional views illustrating a method for forming a landing plug in semiconductor device in accordance with a second preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0015] Hereinafter, a method for forming a landing plug in a semiconductor device will be described in conjunction with the provided drawings.
[0016] [0016]FIGS. 2A to 2 E are cross-sectional views showing a method for forming a landing plug in a semiconductor device in accordance with a first preferred embodiment of the present invention.
[0017] Referring to FIG. 2A, a gate insulation layer 22 is formed on a substrate 20 providing a device isolation layer 21 with a shallow trench isolation (STI) structure. Then, a polysilicon layer 23 and a metal layer 24 are sequentially formed thereon. Herein, the substrate 20 is made of silicon and the gate insulation layer 22 is made of a silicon oxide layer employing SiO 2 or oxynitride such as Si—O—N. Also, the gate insulation layer 22 can be made of a metal oxide layer containing any metal selected from a group consisting of Hf, Zr, Al, Y, Ce, La, Th and Ta or a mixture of theses metal elements or a stacked layer containing some of the above metal elements. Moreover, the gate insulation layer 22 can be made of a silicate layer containing metal.
[0018] Next, on top of the metal layer 24 , a hard mask 25 is formed, and then, the metal layer 24 and the polysilicon layer 23 are etched with use of the hard mask 25 so that a gate 200 is formed. Afterwards, an insulation layer is deposited on an entire surface of the substrate 20 and proceeded with a blanket etch process so as to form a spacer 26 at lateral sides of the hard mask 25 and the gate 200 .
[0019] Referring to FIG. 2B, an inter-layer insulation layer 27 is deposited on an entire surface of the substrate 20 to fill a space between the spacers 26 . Next, with use of a CMP process, the inter-layer insulation layer 27 is entirely etched to expose a surface of the hard mask 25 and the substrate 20 is planarized thereafter. Then, the inter-layer insulation layer 27 is etched in such a manner to expose a partial portion of the substrate 20 between the spacers 26 , whereby a contact hole 28 is formed.
[0020] Referring to FIG. 2C, on the substrate 20 disposed inside of the contact hole 28 , silicon is grown to have a predetermined thickness by employing a selective epitaxial growth (SEG) technique so that a silicon layer 29 , which is a first conductive layer for a landing plug, is formed. Preferably, the silicon layer 29 has a thickness ranging from about 10 Å to about 2000 Å.
[0021] Referring to FIG. 2D, a tungsten silicide WSi x layer 30 , which is a second conductive layer for the landing plug, is formed on the inter-layer insulating layer 27 so as to be buried into the contact hole 28 on which the silicon layer 29 is formed. Preferably, the WSi x layer 30 has a thickness from about 100 Å to about 2000 Å. In addition to the use of the WSi x layer, it is possible to use any layer selected from a group consisting of a TiSi x layer, a CoSi x layer, a NiSi x layer, a TaSi x layer, a HfSi x layer, a ZrSi x layer, a FeSi x layer, a YSi x layer and a MoSi x layer. At this time, the notation x indicating the number of atoms presenting in a molecule ranges from about 0.5 to about 2.5.
[0022] Referring to FIG. 2E, the WSi x layer 30 is entirely etched to expose surfaces of the hard mask 25 and the interlayer insulation layer 27 through a CMP process so that a landing plug 300 including the WSi x layer 30 and the silicon layer 29 is formed.
[0023] According to the above-preferred embodiment of the present invention, since the landing plug 300 is formed by stacking the silicon layer 29 and the WSi x layer 30 through the use of the SEG technique, it is possible to reduce a resistance in more extents compared to the prior art as well as to decrease a resistance-capacitance (RC) delay. These effects make further possible for the landing plug 300 to be correspondent to the demands of high-integration and high-speed in a semiconductor device. Also, the SEG technique used for forming the landing plug 300 solves the gap-fill problem arose by using the conventional method even though a contact hole depth increases and simplifies subsequently performed processes due to an elimination of the CMP process.
[0024] Additionally, even though the first preferred embodiment shows the case of using the WSi x layer 30 for the second conductive layer for the landing plug, it is possible to use alternatively a double layer of W/WN x formed by sequentially depositing a WNx layer and a W layer. This alternative use of the double layer will be described in the following preferred embodiment with reference to FIGS. 3A to 3 E.
[0025] Referring to FIGS. 3A to 3 C, a device isolation layer 41 with a STI structure is formed on a substrate 40 , and then a gate insulation layer 42 , a gate 400 , a hard mask 45 , a spacer 46 , an inter-layer insulation layer 47 , a contact hole 48 and a silicon layer 49 are sequentially formed on the substrate 40 . Herein, the silicon layer 49 is a first conductive layer for a landing plug and is formed through a SEG technique.
[0026] Referring to FIG. 3D, a WN, layer 50 , which is a second conductive layer for the landing plug, is formed on the contact hole 48 in which the silicon layer 49 is formed and a surface of the substrate 40 . Afterwards, a W layer 51 is formed on the WN x layer 50 in such a manner of being buried into the contact hole 48 including the WN x layer 50 . Preferably, each of the WN x layer 50 and the W layer 51 has a thickness ranging from about 20 Å to about 2000 Å. Also, instead of using the W layer 51 , such layer including any element selected from a group consisting of Ta, Ti, Mo, Cr, Hf, Zr, Ru, Ir and Pt can be alternatively used. Instead of the WN x layer 50 , it is possible to use metal nitride including any element selected from a group consisting of Ta, Ti, Mo, Cr, Co, Hf and Zr. At this time, the notation x indicating the number of atoms presenting in a molecule ranges from about 0.1 to about 1.0. Also, the WN x layer 50 can be substituted with any layer selected from a group consisting of a Wsi x N y layer, a TaSi x N y layer, a TiSi x N y layer, a TiAl x N y layer, a TaAl x N y layer, a RuTi x N y layer and a RuTa x N y layer. At this time, each notation of x and y both indicating the number of atoms presenting in a molecule ranges from about 0.1 to about 4.0. Also, a RuO x layer or an IrO x layer can be used instead of the WN x layer 50 . At this time, the notation x indicating the number of atoms presenting in a molecule ranges from about 0.1 to about 3.0.
[0027] After forming the WN x layer 50 and the W layer 51 , an annealing process is performed for crystallization of the WN x layer 50 and the W layer 51 and denudation of N. Preferably, the annealing process is carried out at a temperature in a range from about 600° C. to about 1000° C. for about 10 seconds to 1 hour. At this time, the notation x indicating the number of atoms presenting in a molecule ranges from about 0.1 to about 1.0. Subsequent to the annealing process, the W layer 51 and the WN x layer 50 are entirely etched to expose surfaces of the hard mask 45 and the inter-layer insulating layer 47 with use of a CMP process. After these series of processes, a landing plug 500 staked of the W layer/WN x layer/silicon layer is formed as shown in FIG. 3E.
[0028] Meanwhile, in the second preferred embodiment, the CMP process is performed after the W layer 51 and the WN x layer 50 are deposited and annealed. However, it is possible to perform the CMP process prior to the annealing process. Furthermore, it is also possible to deposit solely the WN x layer 50 without the W layer 51 . In this case, the notation x indicating the number of atoms presenting in a molecule has a value ranging from about 0.1 to about 1.0. In addition, instead of forming the WN x layer, a SiNe layer can be deposited to a thickness from about 10 Å to about 20 Å. At this time, the notation x indicating the number of atoms presenting in a molecule ranges from about 0.1 to about 3.0.
[0029] According to the above-described first and the second preferred embodiments, it is possible to obtain a sufficiently low resistance corresponding to demands of high-integration and high-speed in a semiconductor device by forming a landing plug in a stack layer of the silicon layer and the WSi x layer or the W layer and the WN x layer.
[0030] While the present invention has been described with respect to certain preferred embodiments, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the scope of the invention as defined in the following claims. | The present invention relates to a method for forming a landing plug capable of securing a low resistance by employing a selective epitaxial growth technique to meet demands of high-integration and high-speed in a semiconductor device. The method includes the steps of: forming an inter-layer insulation layer on a substrate; forming a contact hole by etching the inter-layer insulation layer until exposing a partial portion of the substrate; forming a first conductive layer with a predetermined thickness inside of the contact hole, the first conductive layer being made of a silicon layer; forming a second conductive layer on the inter-layer insulation layer in such a manner of being buried into the contact hole in which the silicon layer is formed; and performing a blanket etch process to the second conductive layer until exposing surfaces of the inter-layer insulation layer and the hard mask so that a landing plug is formed. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to semiconductor devices and more specifically to MOS field effect transistors.
2. Prior Art
MOSFET devices are well known in the prior art and are described in many patents and publications. One such source of prior art practice is a book "MOS Integrated Circuits" (1972) edited by William M. Penney and Lillian Law.
The Structure of a Mosfet device, as disclosed by the prior art, includes a monocrystalline semiconductor region (e.g., substrate wafer) with a pair of closely spaced regions on the surface, opposite in conductivity type as compared with the substrate, called the source and the drain. A gate electrode, made either of an appropriate material, such as, a metal, or a semiconductor material, removed from the wafer by a layer of insulating material such as silicon oxide or nitride or a combination thereof which insulating Material covers the area between the source and the drain. Various maskings, oxidation steps and metalizations are used in the process of forming the device elements and making contact with them. The impedance existing between the source and drain elements is controlled by the potential applied to the gate element.
Certain difficulties have been noted in the prior art devices which have been eliminated by the present invention. For example, in prior art devices "junction spiking" is a very common defect. This defect comes about because of the preferential etching which occurs along the 100 plane in a monocrystalline silicon wafer (hereinafter referred to as "100 plane silicon"). The 100 plane silicon is often used in n-channel MOS devices although 111 plane silicon may be employed. (In 111 plane silicon the preferential etching tends to occur in a lateral plane.) The preferential etching defect results from the processing temperatures commonly used after metalization (e.g., aluminum), which enables material from the substrate (e.g., silicon) to diffuse from the contact area of the substrate into the metalization and conversely the metalization flows to fill the voids in the substrate (e.g., contact areas of substrate). Thus, the substrate material dissolves in the metalization. Further, the matalization (e.g., aluminum) often dissolves the substrate material (e.g., silicon) in a preferential manner that produces metal penetration much further into the substrate than would be the case if the dissolution of the substrate and the subsequent penetration by the metalization were isotropic (radiating equally in all directions). If the metalization penetrates through the junction it often results in a short of the junction. This phenomena is known in the industry as junction spiking. As will be described later, preferential etching does not tend to occur in the invented device. In addition, the junctions can be preferentially deepened in the vicinity of the contacts. Both of these improvements result in a device that is much less prone to junction spiking.
An important use of MOS devices is for dynamic memory purposes. In this application, information may be stored in the cell for a short period of time due to the effect of minority carrier lifetime in the source and drain elements and associated effective capacitance. In prior art devices the storage time available is often quite short and very sensitive to the presence of certain impurities in the semi-conductor material. Because of the greatly increased minority carrier lifetime of a cell employing the invention, the yields of parts with an acceptable storage time can be significantly increased. Alternatively, it is possible to maintain the present yields and produce parts having a substantially longer refresh cycle. Thus, when circuits employing the invention are in use, it is possible that such circuits will employ a much smaller percentage of available system time to restore and maintain the stored information. In substance, a dynamic cell is, without structural addition or the addition of components, made to approach the performance of a static cell which generally requires many more components. This result is attained with a number of other advantages incident thereto. For example, it is possible in an n-channel MOS device to deepen the junctions in the vicinity of the contacts to the source and drain without making the source and drain equally deep at portions directly adjacent the gate. Thus, low gate to drain capacitance may be obtained enabling high-speed performance while permitting simple metalization. Also, the metal cracking problem is simultaneously provided for and greater flexibility and tolerance are enabled in the metalization.
SUMMARY OF THE INVENTION
The present invention is described herein, by way of example, as a silicon gate MOSFET, however, the invented method is applicable to various forms of field effect devices such as, for example, metal gate MOS, silicon gate MOS, FAMOS devices, MNOS devices, charge coupled devices bucket brigade devices, or silicon on sapphire or other insulator devices. All such devices and similar devices shall be within the term "field effect device."
The processing of a MOSFET device in accordance with the present invention proceeds along conventional lines up to the metalization of contacts onto the source, drain and gate elements. After preparation for metalization, including masking, etc., but prior to metalizing, a heavy doping of phosphorous or arsenic or other material is made onto the surface of the wafer, resulting in a heavily doped n++ region in both the source and drain. This step is followed by an etchant dip to remove any oxides formed on the surfaces where electrical contact will be made to the device and then metalization is accomplished as disclosed by the prior art.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view of a substrate on which the invented MOS device is fabricated.
FIG. 2 is the substrate of FIG. 1 after a layer of silicon dioxide has been added thereon.
FIG. 3 is a cross-sectional view of the device after removing the oxide coating from an area of the substrate and regrowing a thinner oxide layer.
FIG. 4 is the device of FIG. 3 after deposition of a silicon layer.
FIG. 5 is a cross-sectional view of the device after the silicon gate has been formed.
FIG. 5A is a perspective view of a portion of the device at the stage of FIG. 5.
FIG. 6 is a cross-sectional view of the device after formation of the source and drain.
FIG. 7 shows the addition of layer of silicon oxide to the device as shown in FIG. 6.
FIG. 8 is a cross-sectional view of the device after having a portion of the silicon oxide layer removed over the source and drain.
FIG. 9 is a cross-sectional view of the device of FIG. 8 after a diffusion of phosphorous.
FIG. 10 is a cross-sectional view of a completed MOSFET made in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
In accordance with one embodiment of the invention, a substrate or region of p-type monocrystalline silicon (e.g., with 100 plane orientation) is used to form an n channel MOS field effect transistor. The substrate may be a thick, mechanically substantial wafer or may be a thin layer of p-type silicon deposited on some other form of base. For example, one type of construction which could be used is the so-called silicon on sapphire configuration which consists simply of a thin layer of silicon deposited on a sapphire wafer. The substrate, whether it be mechanically independent or merely a layer on another base in indicated in FIG. 1 by numeral 10. While only one device is shown being fabricated on the substrate, common practice is to use a single substrate wafer for a large number of devices (e.g., 100 or more chips each containing 1000 or more MOSFETS).
By way of an example but not as a limitation, the invention will be described as it applies to a fairly common n-channel Si gate process. The first step of the process is the growing of a thick layer of silicon oxide 11 (e.g., Si O 2 ) on the top surface of the substrate 10 as shown in FIG. 2. The thickness of the layer is typically one micron thick. Alternatively, this layer may be chemically deposited. Next, the area which is to be the site of the invention MOS device is etched, using conventional photo fabrication techniques, to remove a portion of the oxide layer 11 or the site of the invention device may be left substantially non-oxide covered by the presence of a suitable oxidation barrier (silicon nitride) during the growth of the thick oxide. (For example, see Electronics, Dec. 21, 1971, pp. 43-48.) A thin layer of silicon dioxide 12, typically 1000 angstroms thick, is then regrown or deposited in the etched area. The device at this stage of fabrication is shown in FIG. 3.
A layer 13 of polycrystalline silicon is then deposited over the entire surface of the wafer as shown in FIG. 4. Portions of this layer 13 and layer 12 are then removed, again by standard prior art techniques, leaving only strips of polycrystalline silicon which are to become either the gate element of the device (layer 13) or interconnects. The layer 13 is seen to be separated from the substrate 10 by a thin insulating layer of silicon dioxide 12. (It should be noted that an opening in the thin oxide may be appropriate prior to forming layer 13 whereupon the layer 13 may then also be employed as a contact and an interconnect in accordance with U.S. Pat. No. 3,699,646 assigned to the assignee of the subject invention.)
Next, source 14 and drain 15 are formed and the gate is doped with an n type impurity (e.g., phosphorous, arsenic, antimony, etc.), as is done in the prior art. Subsequently, the entire wafer surface is covered with a coating of silicon dioxide 16 by vapor deposition. (These steps are illustrated in FIGS. 6 and 7.) Openings are then etched through oxide coating 16 to uncover a portion of the source 14 and drain 15. It should be understood that while reference has been frequently made above to diffusion, ion implantation may be employed in combination with diffusion or alone to obtain a desired impurity profile. This is true throughout the application where reference is made to diffusion.
The process to this point has been disclosed in the prior art and has been in common use for some time and consequently, the description has not been greatly detailed. There are numerous alternatives to arriving at the same general partially completed device shown in FIG. 8 with various steps rearranged and/or other steps or materials added or deleted.
The next steps in the process would normally involve the forming of a metalization layer. In the subject invention, prior to metalization and after formation of the source and drain (or other region), the surface is subjected to a heavy diffusion of an n-type impurity which causes regions 17 and 18 of n++ conductivity type silicon to be formed in the substrate (e.g., solid solubility at over 1000° C. Preferably, phosphorous is employed as the impurity or dopant. The phosphorous diffusion is preferably made heavy enough and at a temperature to cause rounding of the corners on layer 16 of silicon oxide. This corner rounding makes possible smaller than standard sized metal interconnects, thereby saving space. It should be noted that an earlier glass forming step may be employed to assist in rounding the corner. This aspect of the process is disclosed in Great Britain Patent No. 1,326,947 assigned to the assignee of the subject application. It should be noted that in one form of the invention the additional diffusion or impurity addition is employed with a prior diffusion or impurity addition wherein in both instances the impurity employed is phosphorous. It is possible and desirable in some devices to employ arsenic or antimony as an impurity in connection with the first diffusion or impurity addition and phosphorous in connection with the second impurity addition to the source and drain region. Since arsenic and antimony are much slower diffusants than phosphorous, this will result in a shallow junction in the region most closely adjacent the gate and a substantially deeper junction in the portion of the source and drain removed from the gate and in the proximity of the contact metalization. Thus, the gate to drain capacitance is maintained at a relatively low value providing high speed performance while all of the advantages of the invention are attained.
Following the extra diffusion the wafer is then dipped in an etchant which thins layer 16 somewhat and removes any oxides formed during the phosphorous diffusion. After the etchant dip, the device is completed by formation of contacts 19 and 20 on the surface of the wafer, which may provide a means for connecting the device to an external circuit, to other devices on the same substrate, or to another layer of interconnect.
The very high surface concentration of phosphorous has been found to have some unique, important and surprising results. The silicon at the surface appears to be strained by the diffusion to such an extent that there is no longer preferential etching in the "100" direction and consequently "spiking" of the source and drain junctions is substantially reduced. In addition, the source and drain are driven deeper so that any spikes, if such did exist, would not be as apt to penetrate the junctions. The nature of the source and drain are also changed to enable an alloying cycle of a less critical nature and/or to permit pure aluminum to be used rather than an aluminum silicon alloy for metalization.
Another important result of the invented device is that the bulk lifetime of minority carriers is greatly increased so that when being used as a part of a dynamic memory device, the refresh rate can be substantially reduced. In one experiment refresh rates for prior art devices were in the order of 10 microseconds to a millisecond whereas, with the invented device, a refresh rate of 0.5 seconds to 2 seconds was noted. This dramatic result which was not contemplated is apparently attained by the placing of a gettering material (heavily n++ phosphorous doped material) in contact with the substrate and in such close proximity to the junction of the device. It should be noted that all of the advantages of the present invention are accomplished without an additional masking step. This is particularly important since the addition of masking steps commonly decreases the yields and densities attainable.
The present invention has been described as a conventional n channel MOS device, but it will be clear to those skilled in the art that the same principles can be applied to other devices with advantage. For example, it is contemplated within the spirit of the invention that charge coupled devices or stepless MOS devices can be constructed in accordance with the present invention. While in the presently preferred embodiment of the invention, the n++ diffusion is of phosphorous, it has been found that in some devices arsenic could also be used with similar advantages. | An n channel MOSFET transistor which includes doping of previously formed source and drain elements with a heavy diffusion of phosphorous or arsenic creating n + + regions in the source and drain. The extra diffusion step is preferably accomplished just prior to contact metalization. | 8 |
FIELD
The present invention relates, generally, to systems and methods usable to perforate a barrier within a wellbore or other downhole component or object. Embodiments further relate to systems having a modulated, throttled velocity of work flow usable to eliminate formation damage and near-wellbore damage typically caused by explosives.
BACKGROUND
During well construction and other downhole operations, it is common for penetrations (e.g., perforation operations) to be necessary to open a wellbore or other cavity to the surrounding annulus and/or to open the wellbore or other cavity to a geological face or other environment.
Typically, drilling equipment or perforator systems require use of high energy force applications, mostly through the use of explosives. When utilizing mechanical drilling systems, there is a propensity to undercut, requiring added time and deployments, or to overcut, likely rendering the well feature irreparably damaged. Use of explosives has long been known to generate considerable collateral damage to the cement and formation in the vicinity of the penetrator. Near wellbore damage can result in drastic reductions in wellbore inflow of pay material, and in some instances can result in the migration of pay material or contaminants into adjacent zones, sometimes referred to as “thief zones.”
A need exists for systems and methods that are usable for generating a perforation through a casing element to eliminate excessive damage to the casing, cement, and/or the formation.
A further need exists for systems and methods that are usable for creating a penetration through a wellbore or other element having an advantageous “exit chamfer” profile, in which the systems and methods are also usable for future exiting of tool systems, broaching into the backside geology for material recovery, or injection of materials/fluids into a formation.
A need also exists for systems and methods that are capable of modulating the amount of energy applied to a structural member to affect the proper chamfer, breach depth, and formation erosion.
A need also exists for systems and methods that are able to produce a throughput in a structural member, which does not produce occlusive debris, possibly occluding the desired perforation.
A need also exists for systems and methods that are able to produce multiple penetrations in a single deployment when deployed according to the physical characteristics of the perforation zone, based on temperature, pressure, and fluid medium.
A need also exists for systems, methods, and apparatus capable of producing penetrations on multiple planes in a single deployment.
A need also exists for systems and methods of orienting perforations within wellbores and other cavities that are presented in horizontal, vertical, or diagonal composition.
A need also exists for systems and methods, capable of the above, that can be activated using multiple methods, such as electric wireline, slickline (trigger), and pressure firing, as well as existing conventional methods.
A need also exists for systems and methods that are capable of perforating target components without relying on features of the target, other than the outside diameter. This performance measure indicates that the target material thickness does not affect the quality of the perforation, enabling embodiments of the present invention to be used as a “one size fits all” operation within diameter families.
An additional need exists for a perforation system that contains oriented fuel, such that the orientation of a burn-rate can accelerate or retard the mass flow rate.
An additional need exists for a perforating system having a velocity that can be modulated by varying the fuel type and position with respect to other fuels having faster or slower reaction rates. The physical geometry of the fuel can also be modified or chosen to produce a progressive or non-progressive burn rate. Additionally, multiple fuel types can be modeled such that layered fueled can be utilized.
Embodiments of the present invention meet these needs.
SUMMARY
Embodiments of the present invention relate, generally, to systems and methods usable to perforate a barrier within a wellbore or other cavity bearing component. Embodiments can include systems and/or apparatus having a modulated, throttled velocity of mechanical work usable to eliminate formation and near-wellbore damage and develop an enhanced chamfer feature upon which to orient wellbore exiting components (e.g., fluids, sand slurry, drilling mechanisms, and/or other substances or objects). As such, embodiments described herein can be used to form one or more openings in a downhole object (e.g., casing), without undesirably damaging additional downhole objects (e.g., cement and/or the formation). The openings can be provided with any desired shape and/or orientation, including a chamfer profile which can be used for future orientation of subsequent components, such as a water jet or similar tool usable to penetrate into the formation, e.g., for production or injection purposes.
In an embodiment, the perforating apparatus, used to form at least one opening in a first downhole object (e.g., casing, tubular conduits), without undesirably damaging a second or additional downhole object(s) (e.g., cement, a producing formation, a geological formation), includes a body having at least one port formed therein, and at least one fuel source disposed in the body. The at least one fuel source can include a characteristic, which produces a selected mass flow rate, a selected burn rate, or combinations thereof, that are adapted to form the at least one opening in the first downhole object while minimizing collateral damage to the second or additional downhole object. The perforating apparatus can further include an initiator, in communication with the at least one fuel source, which causes the at least one fuel source to produce the selected mass flow rate, the selected burn rate, or combinations thereof and to project a force through the at least one port to form the at least one opening in the first downhole object.
In an embodiment of the invention, the perforating head can have one or a plurality of discharge ports, which can include one or more slots, a singular hole, a matrix or plurality of holes having a proximity to one another that can produce an additive effect, or other port configurations depending on the characteristics of the object to be perforated and/or other wellbore conditions. The size, shape, angle, and position of the ports can be selected to affect the shape and/or orientation of the openings formed in a segment of casing or other downhole object, such as by affecting the Mass flow rate therethrough.
The perforating head can be deployed in conjunction with an orienting “lug” usable to position toolstring members with a general face of the tool (e.g, the location of one or more discharge ports) facing away from the maximum gravitational vector, or in another desired orientation.
In an embodiment of the invention, the perforator head can possess a thermal barrier and a structural member.
In another embodiment of the invention, the perforator head can contain a dual use head section having a cavity filled with a wellbore fluid that can act as a mechanical dampener during initial fuel content expulsion. In a further embodiment, one or more of the ports can be occluded by the tool system operator in the field, which can allow the perforation pattern to be modified in-situ.
The tool apparatus can have selected mass flow as directed by the operator of the tool system. The mass flow expectation is a function of the target material removal volume, the geometric basis of the tool to target size ratio, the hydrostatic pressure at the perforation, the temperature of the perforation location, the presence or lack or circulation within the wellbore, and the presence or lack of vertical wellbore condition. Specifically, in an embodiment, the fuel load of the apparatus can be configured to provide a desired mass flow and/or burn rate, e.g., through use and relative orientation between different fuel types, and/or fuel sources having differing shapes or physical geometries. The mass flow and/or burn rate can be selected based on various wellbore conditions, the thickness of the downhole object to be perforated (e.g., the outer diameter of a segment of casing), such that an opening having the desired shape can be formed without damaging other downhole objects (e.g., the cement or formation).
In an embodiment, the toolstring apparatus can contain an anchoring system for allowing selective prepositioned anchoring with respect to wellbore depth in proximity to a target zone, and/or the ability to be oriented radially about a wellbore for directional perforation applications. Such depth fixation and directional (azimuthal) locking allows for the energy delivered by the tool to act in the most advantageous direction for well production or injection. This capability becomes very productive when an expectation of horizontal perforations (180 degree phasing) is posed while in a horizontal or substantially horizontal phase of a wellbore, enabling operation to be performed with characteristics specific to horizontal and/or lateral production zones. In events where canted fissures or geologic patterns exist, the tool system can be directed and fixed in a position usable for up thrust conditions.
In another embodiment of the invention, the perforating system can have an activating system utilized to begin the fuel load burning process. A common device used for this process is a Thermal Generator (THG), available from MCR Oil Tools. THG systems can be activated using electrical current produced at the surface through electric wireline (E-line), with a downhole triggering unit generating current from a battery pack and conveyed on slickline, and/or using a “CP Initiator” or similar device delivered on coiled tubing or pipe.
The systems, methods, and apparatus described herein can thereby be used to perforate an object (e.g., a segment of casing) within a wellbore while minimizing or eliminating undesired damage to cement, the formation, and/or other near-wellbore damage, e.g., through use of a modulated, throttled velocity of mechanical work. The perforations formed can include an enhanced chamfer feature upon which substances and/or components (e.g., fluid, slurries, and drilling mechanisms) can be oriented and/or passed therethrough. This enhanced chamfer feature is also usable for later exiting of tool systems, broaching into the backside geology for material recovery, and/or injecting materials and/or fluids into a formation. In addition to eliminating excessive cement or formation damage, use of the present systems, methods, and apparatus can avoid production of occlusive debris that can hinder the operation of one or more perforations in the apparatus, and/or hinder other wellbore operations. The characteristics of the chamfer, the breach depth, and the amount of formation erosion can be controlled through modification of the amount of energy applied to a structural member, e.g., through use of the modulated, throttled velocity, described above, which can be performed through selection and orientation of the fuel load, selection and orientation of ports in the perforator, and positioning of the perforator relative to the object to be perforated (e.g., the offset).
The resulting systems, methods, and apparatus can thereby have the ability, when deployed according to the physical characteristics of the perforation zone, e.g., based on temperature, pressure, and/or fluid medium, to produce multiple penetrations, or penetrations on multiple planes, in a single deployment, as well as to orient the perforations within well bores and other cavities, that are presented in horizontal, vertical, or diagonal composition.
BRIEF DESCRIPTION OF THE DRAWINGS
In the detailed description of various embodiments of the present invention presented below, reference is made to the accompanying drawings, in which:
FIG. 1A depicts an isometric view of an embodiment of a perforating apparatus usable within the scope of the present disclosure to perforate a barrier within a wellbore or other cavity bearing component.
FIG. 1B depicts a side disassembled view of the perforating apparatus of FIG. 1A .
FIG. 2A depicts a side view of a tubular member having an opening formed using embodiments of an apparatus usable within the scope of the present disclosure.
FIG. 2B depicts a side cross-sectional view of the tubular member of FIG. 2A , taken along line A-A.
FIG. 2C depicts a top cross-sectional view of the tubular member of FIG. 2A , taken along line B-B.
Embodiments of the present invention are described below with reference to the listed Figures.
DETAILED DESCRIPTION OF THE EMBODIMENTS
Before explaining selected embodiments of the present invention in detail, it is to be understood that the present invention is not limited to the particular embodiments described herein and that the present invention can be practiced or carried out in various ways.
Embodiments usable within the scope of the present disclosure relate, generally, to systems and methods usable to perforate a barrier within a wellbore or other cavity bearing component. Embodiments further include systems and/or apparatus having a modulated, throttled velocity of mechanical work usable to eliminate formation and near-wellbore damage and to develop an enhanced chamfer feature upon which wellbore exiting components can be oriented, including fluids, sand slurry, drilling mechanisms, and other components.
Systems and methods usable within the scope of the present disclosure can thereby generate a perforation through, e.g., a casing element, that eliminates excessive damage to the conduit (casing), cement, and/or formation, in addition to avoiding production of occlusive debris that could occlude or otherwise interfere with the perforation.
Embodiments usable within the scope of the present disclosure can further create a penetration through a wellbore, conduit, or other barrier element having an advantageous “exit chamfer” profile usable for later tool system exiting, broaching into the backside geology for material recovery, and/or injecting materials/fluids into a formation, as embodied systems and methods can be capable of modulating the amount of energy applied to a structural member to affect the proper chamfer, breach depth, and formation erosion.
In addition, embodiments usable within the scope of the present disclosure can possess the ability, when deployed according to the physical characteristics of a perforation zone (e.g., temperature, pressure, fluid medium), to produce multiple penetrations and/or penetrations in multiple planes, in a single deployment, and to orient the perforations within wellbores or other cavities, that are presented in horizontal, vertical, or diagonal composition.
Referring now to FIGS. 1A and 1B , an embodiment of a perforating apparatus ( 10 ) usable within the scope of the present disclosure is depicted. Specifically, FIG. 1A depicts an isometric view of the perforating apparatus ( 10 ), while FIG. 1B depicts a disassembled side view thereof.
The perforating apparatus ( 10 ) is shown having a perforator body ( 12 ), depicted as a generally tubular (e.g., cylindrical) member, having a fuel extension ( 14 ) at one end and a perforating head ( 16 ) at the opposing end. While FIGS. 1A and 1B depict the perforator body ( 12 ), fuel extension ( 14 ), and perforating head ( 16 ) as separate components that can be connected together (e.g., via threaded connections, force and/or snap fit, welding, etc.), in various embodiments, one or more parts of the perforating apparatus ( 10 ) can be integral and/or otherwise formed as a single piece. Similarly, any portions thereof can include multiple parts to facilitate transport, storage, and/or manufacture.
The fuel extension ( 14 ) can be provided with one or more types of fuel (e.g., varying grades and/or compositions of thermite or similar non-explosive, ignitable substances, and/or other types of generally non-explosive substances usable to produce a force when ignited or otherwise reacted), the types of fuel being arranged and/or oriented to control the rate of exodus of mass and/or force from the fuel extension ( 14 ) and the propagation thereof through the perforator body ( 12 ). For example, the position of certain types of fuel can be varied with respect to other types of fuels having faster or slower reaction rates. The physical geometry of the fuel (e.g., the shape of solid thermite pellets and/or discs) can be chosen based on the desired progressive or non-progressive burn rate. Additionally, one or more fuel types can be layered. The fuel extension ( 14 ) and/or the perforator body ( 12 ), while depicted as tubular components, can include various internal features and/or material characteristics to desirably affect the propagation of mass and/or force therein, and/or the burn rate of various contents.
The perforator head ( 16 ) is shown having multiple ports ( 18 ) (e.g., slots, holes, orifices, or other types of openings) therein. It should be understood that each depicted port ( 18 ) can be representative of one opening or multiple closely-spaced openings. Further, it should be understood that while FIGS. 1A and 1B depict multiple, generally rectangular slots in the perforator head ( 16 ), any number and placement of ports can be provided, and the ports ( 18 ) can have any shape and/or angle, depending on the direction and desired propagation of force and/or mass therethrough. In an embodiment, the ports ( 18 ) can include one or more matrices of holes spaced such that discharge therethrough provides an additive effect. The number, shape, orientation, and position of the ports ( 18 ) can be selected to desirably affect the mass flow rate therethrough, and subsequently, the formation of an opening in a downhole object. Embodiments can also include one or more internal features usable to occlude (e.g., wholly or partially block/obstruct) one or more ports, to enable selective control of force and/or mass produced by reacting fuel within the perforating apparatus ( 10 ). Such internal features can be remotely actuated and/or directly actuated (e.g., through use of an electric line, a slick line, other forms of control lines, and/or through shearing of pins and/or other frangible members), such that a movable physical barrier is moved into a position that occludes one or more of the ports ( 18 ).
An anchor ( 20 ), such as a pressure balance anchor available from MCR Oil Tools, or a similar type of anchoring device, is shown engaged with the perforating head ( 18 ) for facilitating positioning of the perforating apparatus ( 10 ) at a selected depth and/or within a selected zone of a wellbore. The anchor ( 20 ) can be used to radially orient the perforating apparatus ( 10 ), e.g., when it is desired to perforate in a desired direction by positioning and orienting the ports ( 18 ) in the desired direction, and/or to control the offset between the perforating apparatus ( 10 ) and the object to be perforated. Fixation of the perforating apparatus ( 10 ) at a desired depth and in a desired directional (e.g., azimuthal) orientation allows the perforating apparatus ( 10 ) to be positioned to project mass and/or force through the ports ( 18 ) in a manner determined to be most advantageous for production or injection, especially when used within a horizontal portion of a wellbore. A bull plug ( 22 ) or any other manner of barrier and/or end cap can be provided at the end of the anchor ( 20 ), or alternatively, the anchor ( 20 ) could be formed with a closed end or similar external or internal barrier therein.
FIGS. 1A and 1B also depict a thermal generator ( 24 ) secured to the fuel extension ( 14 ). It should be understood that while a thermal generator ( 24 ), such as one available from MCR Oil Tools, is shown and described herein, other types of ignition and/or initiation devices can be used, depending on the type(s) of fuel used within the fuel extension ( 14 ), and any characteristics of the object to be cut and/or the wellbore environment. An isolation sub ( 26 ) is shown disposed at the opposing end of the thermal generator ( 24 ), for isolating and/or insulating the perforating apparatus ( 10 ) from other components along the same conduit and/or or within the wellbore.
It should be understood that the depicted arrangement and orientation of components is merely an exemplary embodiment, and that any of the components of the perforating tool ( 10 ) described above could be otherwise arranged, configured, or omitted. For example, while FIGS. 1A and 1B depict an anchor ( 20 ) disposed in a downhole direction from the perforating head ( 16 ), embodiments could include an anchor ( 20 ) disposed uphole from the perforating head ( 16 ), or use of an anchor ( 20 ) could be omitted when unnecessary. Similarly, while FIGS. 1A and 1B depict a thermal generator ( 24 ) disposed in an uphole direction from the perforator body ( 12 ) and fuel extension ( 14 ), in various embodiments, the thermal generator ( 24 ) or similar initiation and/or ignition source could be downhole from the perforator body ( 12 ). Similarly, the fuel extension ( 14 ) could be positioned downhole from the perforator body ( 12 ), and/or the perforating head ( 16 ) could be positioned uphole from the perforator body ( 12 ).
Referring now to FIGS. 2A, 2B, and 2C , an embodiment of an opening ( 30 ) formed in a tubular member ( 28 ) (e.g., a joint of casing) using embodiments of apparatuses usable within the scope of the present disclosure, is shown. Specifically, FIG. 2A depicts a side view of the tubular member ( 28 ), FIG. 2C depicts a top cross-sectional view thereof, taken along line B-B, and FIG. 2B depicts a side cross-sectional view thereof, taken along line A-A. As described previously, openings formed using embodiments described herein can be provided with a desired shape, e.g., an “exit chamfer” feature, which can be used for future locating and positioning of tools, and for advantageously exiting the tubular member ( 28 ) into the formation (e.g., for injection or extraction operations) using subsequent tools.
FIGS. 2A, 2B, and 2C depict the tubular member ( 28 ) having four openings ( 30 ) formed therein, each opening ( 30 ) disposed approximately ninety degrees about the circumference of the tubular member ( 28 ) from each adjacent opening ( 30 ). It should be understood, however, that embodiments usable within the scope of the present disclosure can create any number of openings in an object, and that the resulting openings can have any desired position and/or orientation relative to one another. Further, while FIGS. 2A, 2B, and 2C depict openings ( 30 ) having the “exit chamfer” profile described above, it should be understood that various embodiments could provide any desired shape to the openings ( 30 ), e.g., to facilitate subsequent locating and positioning operations.
Each opening ( 30 ) is shown having a chamfered surface ( 32 ) extending between the outer diameter ( 33 ) and the inner diameter ( 31 ) of the tubular member ( 28 ). The chamfered surface ( 32 ) is shown having a generally curved, angled, and/or sloped shape, which can be curved, angled, and/or otherwise sloped, thereby providing the openings ( 30 ) with an outer end ( 34 ) having a diameter narrower than that of their inner end ( 36 ). The curve and/or angle of the chamfered surfaces ( 32 ) facilitates future location and positioning of tools, e.g., through use of objects having protrusions adapted to locate and/or engage the openings ( 30 ). Additionally, the chamfered surfaces ( 32 ) provide a contour suitable for orienting subsequent tools, usable to bore into the adjacent cement and/or formation, extract substances therefrom, and/or inject substances therein.
While various embodiments of the present invention have been described with emphasis, it should be understood that within the scope of the appended claims, the present invention might be practiced other than as specifically described herein. | Apparatus, systems, and methods, for perforating a downhole object while minimizing collateral damage to other objects, include use of a perforating device having a body, at least one fuel source having a characteristic that produces a selected mass flow rate, a selected burn rate, or combinations thereof, and an initiator for reacting the fuel to project a force through at least one port in the body. Characteristics of the at least one fuel source can include use of differing fuel types, shapes, and placement to achieve the desired mass flow rate or burn rate, and thus, a controlled force from the apparatus. An anchor or similar orienting device can be used to control the direction and position from which the force exits the apparatus. Openings formed in downhole objects can include a chamfered profile for facilitating future orientation or for injecting or removing substances from a formation. | 4 |
[0001] This application claims priority from U.S. Provisional application Ser. No. 61/495216 (“the '216 application”) filed Jun. 9, 2011. The '216 application is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The invention relates to systems for controlling the flow of water in rivers, lakes and manmade channels in order to lower water or tide levels in flooding or other adverse situations.
SUMMARY OF THE INVENTION
[0003] As evidenced by recent events, severe flooding is a constant problem for those areas in the nation near rivers, streams, tributaries and other bodies of water, both natural and manmade. A primary example is the flooding caused by the Mississippi River and its tributaries that drain most of the mid United States. The Mississippi River normally flows at approximately 700,000 to 200,000 cubic feet of water per second (cfs). When snow and rainfall levels in the North are abnormally high, the Mississippi is forced to drain more water than it can safely handle thereby causing higher water levels with overtopping of the levee protection system. In addition this higher river volume increases the water flow rate threatening the structure of the levees. Other natural phenomenon such as the development of sand bars at the mouth of a river cause the river speed to drastically drop, further limiting the ability of the river to move the enormous volume of water draining into it.
[0004] It is an object of the present invention to provide a system or method that will assist the flow of water in rivers, streams, tributaries and other bodies of water, both natural and manmade to lower tide or water levels in order to prevent flooding of homes and properties. Typically, a river is flowing into another body of water such as an ocean, or a drainage canal may flow into a lake. Prime examples are the Mississippi River flowing into the Gulf of Mexico, and drainage canals in the City of New Orleans flowing into Lake Ponchartrain. The draining river or canal must overcome the existing tidewater or water level of the receiving body for water to drain. By anchoring a crew boat or large vessel or a fleet of such vessels at the mouth of the Mississippi River and pointed into the flow of the River, with the engines running, the higher tide will be pushed back into the Gulf, lowering the River level and aiding flow.
[0005] It is an object of this invention to use the propulsive power of marine vessels to move water in the direction of drainage to assist in the natural gravity flow of a river or a canal. Marine vessels are normally powered to be propelled in the water but, if the vessel is retarded or firmly anchored and pointed against the flow of a river and given propulsive power, the propellers will move water in the direction of the river flow, thereby serving as an adjunct or assist to the river flow. By employing a multiplicity of highly powered commercial vessels such as commonly used in the offshore industries, a significant power assist could be provided to river flow.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 depicts a cross sectional view at the mouth of a river with a marine vessel deployed as part of the inventive system and method.
[0007] FIG. 2 depicts a plan view of the inventive system at the mouth of a river and in tributary canals.
[0008] FIG. 3 is a plan view of the 17 th Street Canal in New Orleans during Hurricane Katrina.
[0009] FIG. 4 is a plan view of the same area shown in FIG. 3 , but with the inventive system and method deployed to prevent flooding through the broken flood wall.
DETAILED DESCRIPTION OF THE INVENTION
[0010] In FIG. 1 the inventive tidewater control system 1 is depicted as deployed at the mouth 25 of a river 2 such as the Mississippi River. As the water flows down the Mississippi River towards the Gulf of Mexico, around the City of New Orleans the water or tide is moving at about 3 to 7 mph. When the tide reaches the mouth of the River it slows to about 1 to 2 mph because of the width of the mouth. Because of this, sand and sediment sink and form sand bars that further slow the flow of water.
[0011] As shown in FIG. 1 , at least one powered marine vessel 4 would be anchored in the Gulf of Mexico 3 beyond a sand bar 11 at the mouth 25 of the river 2 with an anchor 9 and mooring line 8 and pointed against the river flow direction 10 . When the engines 12 of the marine vessel 4 is powered to turn the propellers 6 , water as indicated by prop wash 7 will be forced back into the Gulf 3 to lower the tide level 5 in the river 2 and reduce the size of the sand bar 11 . It is understood that, while only one vessel 4 is depicted in FIG. 1 , a multiplicity of vessels, each with one or more engines 12 and propellers 6 , could be engaged in the inventive system 1 .
[0012] FIG. 2 depicts a plan view of inventive tidewater control system 1 deployed at the mouth 25 of a river 2 with a fleet or multiplicity of powered marine vessels 4 anchored with mooring lines 8 and anchors 9 beyond a sand bar 11 and pointed against the river flow direction 10 . As shown in FIG. 1 , when the engines 12 of the marine vessels 4 are powered to turn the propellers 6 , water as indicated by prop wash 7 will be forced back into the Gulf 3 to lower the tide level 5 in the river 2 and reduce the size of the sand bar 11 .
[0013] FIG. 2 also depicts the inventive system 1 deployed in a tributary canal 14 that has a sand bar 11 near the entrance of the tributary canal 14 to the river 2 . The marine vessel 4 would be anchored in the tributary canal 14 pointed against the canal water flow 10 . By powering the vessel 4 through the engines 12 and propellers 6 , water as shown by the prop wash 7 will be forced back the canal 14 to lower the tide level 5 in the river 2 and reduce the size of the sand bar 11 .
[0014] FIG. 3 depicts a plan view of the failure of the flood walls 21 at the 17 th Street Canal 19 in New Orleans during Hurricane Katrina. A breach 23 in the floodwall 21 occurred on the Orleans Parish side of the Canal 19 , opposite the Jefferson Parish side. Also shown is a bridge 17 and road 18 . The breach 23 allowed floodwaters 24 to wash out the mud and clay levee 22 , completely flooding and destroying residences along the side of the Canal 19 . The Canal 19 empties into Lake Ponchartrain 15 . At the time of this flooding the canal water level 20 was plus 15 feet as was the lake water level 16 . These water levels were well above the elevation of the breach 23 , so the flood water 21 continued to flood New Orleans.
[0015] FIG. 4 has the same plan view as shown in FIG. 3 , but with the inventive tidewater control system deployed at the mouth of the canal 19 . As shown, marine vessels 4 are anchored and pointed into the canal 19 . By engaging the engines 12 and propellers 6 , the flood water will be pushed back into the Lake 15 , lowering the canal water level 20 to plus 10 feet below the level of the breach 23 . This example is offered to illustrate the benefits of the inventive system and method that can be deployed rapidly in emergency situations. | A system and method for assisting the flow of water in rivers, streams and tributaries using the propulsive power of anchored marine vessels to move water in the direction of flow to aid flow and lower water levels in rivers, streams and tributaries. | 4 |
TECHNICAL FIELD
[0001] This invention relates generally to homogeneous charge compression ignition (HCCI) engines and, more particularly, to circuitry to control operation of HCCI engines.
BACKGROUND INFORMATION
[0002] In a HCCI engine, the fuel and oxidizer are mixed together similarly as they would be in a spark ignition engine (gasoline engine). In contrast to the homogeneous charge spark ignition engine, which uses an electric discharge to ignite a portion of the fuel/oxidizer mixture, a HCCI engine depends upon spontaneous reaction when the density and temperature of the mixture are raised by compression. until the entire mixture reacts spontaneously. This is similar to a stratified charge compression ignition engine (diesel engine) which also relies on temperature and density increase resulting from compression. However, rather than being spontaneous as in the HCCI engine, combustion occurs in a diesel engine at the boundary of fuel-air mixing, caused by an injection event; introduction of fuel into the already compressed oxidizer is what initiates combustion.
[0003] In both the homogeneous charge spark ignition and the stratified charge compression ignition (HCSI) engines, the burn starts at one (or possibly a few) place and propagates through the fuel/air mixture. In the gasoline (an engine, the flame initiates at an electrical discharge point and propagates through a premixed homogeneous charge of air and fuel. In the diesel (SCCI) engine the flame starts near the one or more injection points via auto-ignition and propagates through a heterogeneous mixture at the moving boundary of fuel air mixing. Under HCCI conditions, a homogeneous mixture of fuel, air, and residual gasses from previous cycles are compressed until auto-ignition occurs. Combustion initiates substantially simultaneously at multiple sites throughout the combustion chamber and there is no discernable flame propagation.
[0004] HCCI engines have a number of advantages: hydrocarbon and CO emissions on par with gasoline engines, efficiency on par with diesel engines, and nitrogen oxide (NOx) emissions that are substantially better than either gasoline or diesel engines. HCCI engines produce no soot and can operate using gasoline, diesel fuel, and many alternative fuels.
[0005] A salient aspect of HCCI engines is that the fuel/air mixture burn virtually simultaneously because ignition starts at several places across the cylinder at once. With no direct initiator of combustion, the HCCI process is inherently challenging to control. To enable dynamic operation in an HCCI engine, the control system changes the conditions that induce combustion. Thus, relevant parameters for the engine to control include: the compression ratio, inducted gas temperature, inducted gas pressure, fuel-air ratio, quantity of retained or reinducted exhaust, and blend of fuel types.
[0006] Another salient aspect of HCCI engines is that they have a narrow power range because spontaneous ignition occurs around a single designed operating point. An engine having a single operating point is certainly useful in a hybrid vehicle. On the other hand, most applications require an engine to be able to modulate its output to meet fluctuations of demand by an operator. For high load operation, the engine may switched over to operate in a spark ignition (SI) mode, leaving HCCI operation for more moderate load operation.
[0007] Due to different characteristics of the HCCI and SI combustions, the in-cylinder ionization signals are quite different, both in magnitude and shape. The ionization signal magnitudes during HCCI combustion is typically more than a factor of ten lower than during SI combustion due to different combustion characteristics (summarized above). As a result, it is very difficult (nearing impossible) to detect ionization current during HCCI combustion mode using an ionization detection circuit that was originally designed for an SI combustion only context.
[0008] What is needed is an apparatus for effective detection of ionization signals in an engine that operates in a HCCI mode as well as a SI mode.
SUMMARY OF THE INVENTION
[0009] In general terms, this invention provides a dual gain circuit and a dual bias voltage circuit for detecting ionization signal using nominal gain and bias voltage when the engine is operated at SI combustion mode and using high gain and bias voltage for MCCI combustion mode.
[0010] According to one aspect of the invention, a detected ionization signal is amplified with a selectable gain controlled by a control input.
[0011] According to another aspect of the invention, an ionization detection bias voltage is selectable based upon a control input to improve detectability of ionization during HCCI operation of an internal combustion engine.
[0012] According to yet another aspect of the invention, a single circuit for operating an ionization detector is responsive to a control input to alter its bias voltage and its gain to selectively enable effective detection of ionization for two different operational modes of an internal combustion engine.
[0013] According to embodiments of the present invention, a dual gain circuit detects ionization signal using a nominal gain when the engines is operated at SI combustion mode and using a high gain for HCCI combustion mode. An advantage of this signal ionization detection circuit is that it is useful for detecting ionization signal at both HCCI and SI operational modes without additional sensing elements.
[0014] These and other features and advantages of this invention will become more apparent to those skilled in the art from the detailed description of a preferred embodiment. The drawings that accompany the detailed description are described below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 illustrates a typical ionization signal and its corresponding in-cylinder pressure signal in a SI combustion mode.
[0016] FIG. 2 illustrates a typical ionization signal, along with its corresponding in-cylinder pressure signal and heat release rate in a HCCI combustion mode.
[0017] FIG. 3 illustrates operational regions for SI and HCCI combustions in terms of cylinder pressure versus rotational frequency.
[0018] FIG. 4 illustrates a conventional ionization detection system architecture.
[0019] FIG. 5 illustrates three regions of a typical ionization signal waveform.
[0020] FIG. 6 illustrates a variable gain ionization detection system architecture according to a first embodiment of the present invention.
[0021] FIG. 7 illustrates a dual bias voltage supply suitable for practice according to embodiments of the present invention.
[0022] FIG. 8 illustrates circuit implementation of dual-gain amplifier for use in embodiments of the present invention.
[0023] FIG. 9 illustrates a variable gain ionization detection system architecture according to a second embodiment of the present invention.
DETAILED DESCRIPTION
[0024] An ionization detection system uses a spark plug as a sensor to observe an in-cylinder combustion process. A bias voltage is applied between the spark plug's center and ground electrodes, and current conduction across the spark plug gap increases monotonically with the amount of ionization present in the cylinder. When the engine is operated at SI mode, the flame starts at the spark plug gap and gradually moves away, and the ionization signal may have more detailed information about in-cylinder combustion than an in-cylinder pressure signal. When the SI engine load is high enough the ionization signal is useful to locate the in-cylinder pressure peak.
[0025] Referring to FIG. 1 , a typical ionization signal 110 is shown for a two-liter four-cylinder SI engine operated at 1500 RPM with 2.62 Bar BMEP, along with the corresponding in-cylinder pressure signal 120 . A typical ionization signal for the engine running in SI combustion mode has two peaks. The first peak 112 is due to the initial flame kernel development right after the spark. When the flame front leaves the spark plug, the magnitude of the ionization signal reduces. As the pressure in the cylinder increases rapidly, the combusted mixture around the spark plug gap is ionized again due to the high temperature resulted from the combustion, that generates the second peak 114 .
[0026] Unlike a traditional SI or Diesel engine, HCCI combustion takes place spontaneously and homogeneously without flame propagation. When the engine is operated in a HCCI combustion mode, the detected ionization signal through the spark plug gap provides local combustion information around the spark plug gap.
[0027] Referring to FIG. 2 , a typical ionization signal 210 is shown, along with its corresponding in-cylinder pressure signal 220 and heat release rate 230 , in a HCCI combustion mode. The ionization signal 210 for the engine running in HCCI mode has only one peak 212 . This signal peak 212 is due to the spontaneously and homogeneously HCCI combustion. The characteristics of the ionization signal are very close to the heat release rate curve 230 , which is calculated from an in-cylinder pressure signal 220 . In fact, the peak locations 212 , 232 of both ionization and heat release rate are almost the same. Due to the lean operation of the HCCI combustion, the magnitude of the HCCI ionization signal (on the order of tens of microamps) is relatively small comparing with the SI signal (on the order of hundreds of microamps).
[0028] Due to low Compression Ratio (CR) gasoline burning HCCI engines obtain advantages by having the flexibility to switch to a SI mode at high load. This ability to revert to an SI mode overcomes the HCCI limitation of a narrow operation range. Thus, a dual mode HCCI/SI internal combustion engine is very practical.
[0029] Referring to FIG. 3 , a graph of cylinder pressure versus rotational frequency shows the typical operation regions of the different combustion modes in a combined HCCI/SI combustion gasoline engine. During the cold-start operation, a stratified local rich fuel/air mixture near the spark plug should be formed in the compression stroke and then ignited by the spark. After the warm-up running, the engine goes into the HCCI combustion region from low to mediate load to have a high thermal efficiency and very low engine-out NOx emission. From mediate high to high load, the engine runs on an SI combustion for high power output. An ionization detection system for this engine should have the ability to detect ionization signal for both SI and HCCI combustion modes. Considering the wide variance in ionization signal size between these two modes, the detection system adapts dynamically to detect ionization signal at different signal levels with consistent signal to noise level. This detection system uses variable bias voltage and gains to detects an ionization signal for an HCCI engine operated alternatively at SI and HCCI combustion modes.
[0030] Referring to FIG. 4 , a conventional ionization detection system is shown, having an is ignition coil L, an Insulated Gate Bipolar Transistor (IGBT) Q that turns the ignition coil L on and off, a spark plug SP, a Zener diode D with its breakdown voltage being higher than the ionization bias voltage, and a dwell current feedback resistor R. The spark control circuit 410 controls the IGBT Q, based upon an ignition control input signal 412 , in a soft turn-on fashion. The voltage developed across the dwell current feedback resistor R is proportional to the actual dwell current.
[0031] Referring to FIG. 5 , a waveform plot shows three regions of a typical ionization signal 510 as output according to a detection system as shown in FIG. 4 . After the falling edge of the ignition control input 412 , the voltage across the spark plug gap SP increases sharply, breaks down the air-to-fuel mixture, and generates an ignition current I 2 flowing into the ground. Therefore, the voltage across the Zener diode D is negative during this period and the ionization current mirror 420 provides a saturated current due to the bias voltage applied to the Zener diode D. After the spark (or ignition) current is diminished, the current mirror circuit 420 provides the combustion ionization signal. The ionization signal 510 is divided into three regions, where the first region 512 is the dwell current signal provided by the current feedback resistor R, the second region 514 is the spark duration signal provided by current mirror circuit during the spark period, and the third region 516 is the combustion ionization signal provided by the current mirror circuit 420 . A signal mixing circuit 430 switches the ionization output to dwell current signal when ignition control is active and switches back to spark and ionization signal provided by the current mirror circuit 420 .
[0032] Referring to FIG. 6 , a variable gain ionization detection system architecture is shown according to a first embodiment of the present invention. In order to detect in-cylinder ionization signal during both SI and HCCI combustion operations, this invention proposed to use different ionization bias voltage and gain at different operational modes. In contrast to the conventional ionization detection circuit shown in FIG. 4 , which has a bias voltage supply 610 based upon flyback voltage, system architecture of FIG. 6 is capable of provide a dual bias voltage controlled by an external control input 620 . The system architecture of FIG. 6 also includes a dual gain amplifier circuit 630 that amplifies the third region 516 only of the ionization signal. Gain is controlled by the same external control input 620 as that controlling selection of bias voltage supply 610 . This control input 620 may be generated by and received from a Powertrain Control Module (PCM), or equivalent control circuitry. For example, the gain control input 620 is high during SI combustion and low during HCCI combustion.
[0033] Referring to FIG. 7 , a schematic of a dual bias voltage supply circuit 700 useful for practice of the present invention is shown. For the dual bias voltage supply circuit 700 , a DC to DC charge pump circuit 710 is used to provide a bias voltage using a battery supplied voltage Vbat that is greater that the sum of breakdown voltages of a pair of series Zener diodes D 1 , D 2 . The charge pump 710 output charges capacitor C 2 through resistor R 1 and the ionization bias voltage output is determined according to the breakdown voltage of the Zener diodes D 1 , D 2 . When the gain control input is low (i.e., during HCCI combustion), a switching transistor Q 1 is switched off and the bias voltage output equals to the sum of the breakdown voltages of the Zener diodes D 1 , D 2 . As an example, the sum of the breakdown voltages of the Zener diodes D 1 , D 2 is 150 volts. Alternatively, when the gain control input is high, the switching transistor Q 1 is switched on, and the bias voltage output equals to the breakdown voltage of only one of the Zener diodes D 1 , where the collect-to-emitter voltage drop across conducting transistor Q 1 is negligibly small compared to the breakdown voltage. As an example, the breakdown voltage of the Zener diode D 1 is 100 volts.
[0034] The ionization detection electronics is optionally integrated on to the ignition coil for both pencil and on-plug coils to maximize the signal to noise ratio. A good reason to do this is the fact that an ionization signal has an amplitude on the order of hundreds of microamps, and a long wiring harness between spark plug and detection circuit would introduce additional electrical noise to the detected ionization signal due to environmental electric and magnetic fields. When integrated thusly, a five pin (minimum) connector for the ionization detection coil is appropriate. The five lines are: battery voltage, ground, ignition control input, ionization signal output, and gain control input.
[0035] As described before, the magnitude of the ionization signal during SI and HCCI combustion modes is quite different. In many situations it is anticipated that the difference is as large as a factor of ten. This causes a scaling problem for the PCM (Power Control Module) to read the ionization signal into the microprocessor. Amplifying the ionization signal inside the PCM would also amplify the additional noise introduced by the engine harness between PCM and ignition coil. Therefore, amplifying the ionization signal with the ionization detection electronics, according to embodiments of the present invention, provides an improved signal to noise ratio.
[0036] A circuit schematic is shown in FIG. 8 for a dual gain amplifier that is configured to suit both voltage-in/voltage-out and voltage-in/current-out requirements.
[0037] The amplifier has an operational amplifier OP-AMP, a switch SW and a transistor Q 2 . The transistor Q 2 is optionally either a bipolar transistor or a MOSFET; for purpose of illustration a bipolar transistor is shown. The switch SW can be a mechanical device, a movable strap or a low impedance electronic switch, such as a MOSFET. The emitter resistors R 4 , R 5 are much larger than the ballast resistor R B .
[0038] Input voltage Vion is a voltage derived from the ionization signal Iion and a resistor Rion. When the switch SW is open the negative node of the OP-AMP is derived from the emitter of the transistor Q 2 , through the emitter resistor R 4 . thus Output voltage Vout matches Vion. This is the case of unity gain. If the output must be the current signal proportional to the input, then the ballast resistor R B is chosen to be equal to Rion.
[0039] When a higher gain is required, the switch SW is closed. The output voltage Vout is attenuated by the voltage divider formed by the emitter resistors R 4 , R 5 and the Vout/Vion ratio (or gain) is given by (R 4 +R 5 )/R 5 . The amplified current output Iout is equal to Vout/Rem, where Rem is the parallel combination of (R 4 +R 5 ) and the input resistor R B . Thus Iout can be written as
[0000] V out/ Vion =( R 4+ R 5)/ R 5
[0000] I out= V out/Rem
[0000] I out= Vion ×[( R 4+ R 5)/ R 5]/[( R 4+ R 5)× R B /( R 4+ R 5+ R B )],
[0000] after simplification which yields
[0000] I out= Vion ×( R 4+ R 5+ R B )/( R 5+ R B )
[0000] or
[0000] I out≈( Vion/R 5)×[( R 4+ R 5)/ R B ], if R B <<R 4+ R 5.
[0040] The current gain (GI), therefore, is given by
[0000] GI=[Vion ×( R 4+ R 5)/ R 5 /R B ]/[Vion/R B ]=( R 4+ R 5)/ R 5.
[0041] Note that by adding more switches and more voltage dividers to the emitter load of transistor Q 2 , amplification of the ionization sensor circuit can optionally have three or more selectable gain settings.
[0042] Referring to FIG. 9 , another implementation architecture of a variable bias voltage and gain ionization detection circuit according to an embodiment of the present invention is shown. In this case the bias voltage supply 910 remains unchanged, unlike in FIG. 6 , and the amplification of the ionization signal is moved from a separate circuit into the ionization detection current mirror circuit 920 .
[0043] The control inputs of the dual-gain amplifier are control input and gain control input. In order maintain unit gain during the dwell period, the switch SW is open whatever the gain control input is. The switch SW is closed only when the gain control input is high (active) and the control input is low (inactive).
[0044] The foregoing invention has been described in accordance with the relevant legal standards, thus the description is exemplary rather than limiting in nature. Variations and modifications to the disclosed embodiment may become apparent to those skilled in the art and do come within the scope of the invention. Accordingly, the scope of legal protection afforded this invention can only be determined by studying the following claims. | Disclosed is a way to detect ionization within a cylinder of an internal combustion engine where the engine selectively operates in either a spark ignition mode or a HCCI mode. A single ionization detector circuit adapts in response to a control input to alter its bias voltage and its gain to selectively enable effective detection of ionization for each of two different operational modes of an internal combustion engine. | 8 |
FIELD OF THE INVENTION
[0001] The present invention relates to a semiconductor memory device, and more particularly, to a multi-port memory device having a serial input/output interface.
DESCRIPTION OF RELATED ART
[0002] A conventional dynamic random access memory (DRAM) operates at a relatively lower speed than a chipset connected to an external device. The DRAM operates at a low frequency and forms a data input/output (I/O) path connected in parallel to an interface that is to be connected to an external device.
[0003] An operating speed of the DRAM is synchronized with that of the chipset in order to increase the entire data transfer rate. However, as faster processing speed is increasingly required, parallel data I/O operation has been limited. Thus, a DRAM using a high-speed serial I/O interface has become necessary.
[0004] As a bottleneck phenomenon can occur in a memory system when a single I/O interface is used, it is unreasonable to use a bandwidth that is much smaller than a maximum bandwidth of a memory core. To solve these problems, there is an increasing demand for a memory device that has a plurality of I/O interfaces, i.e., multi-ports, for the purpose of multiple access. It is expected that a memory device having a serial I/O interface and multi-port will be used as a buffer memory of a display device, for example, HD-TV, LCD, etc.
[0005] FIG. 1 is a diagram of a package ball out configuration of a ball grid array (BGA) packaging in a conventional 60-ball DDR2 DRAM.
[0006] In a single-port memory device having a parallel interface, only a DRAM part operating at a low speed is packaged. Thus, power used in the DRAM is supplied to balls.
[0007] However, if the package ball out configuration of FIG. 1 is applied to a multi-port memory device having a serial I/O interface, package efficiency is degraded.
[0008] The multi-port memory device having the serial I/O interface has transmission pins and reception pins as many as the ports. The transmission pins and the reception pins have a differential structure for data I/O operation. The operation stability can be secured when package loads of the transmission pins and the reception pins (balls) are equal to one another. In the package ball out configuration of FIG. 1 , however, the parallel I/O interface (DQ pin) cannot be replaced with the serial I/O interface. Thus, the package loads of the transmission pins and the reception pins (balls) for the serial I/O interface are not considered.
[0009] In addition, because the high-speed serial I/O interface part and the low-speed DRAM part operate together, the unstable power voltage level caused by the abrupt power consumption at one side degrades the operation stability of the other side. For this reason, most of the multi-port memory devices having the serial I/O interface include separate power supplies for the serial I/O interface part and the DRAM part. If the power supplies are separately provided for the different use, it is difficult to configure a power layer that manages the power supply. When two power supplies have different levels, the above-described problems become more serious.
SUMMARY OF THE INVENTION
[0010] It is, therefore, an object of the present invention to provide a multi-port memory device having a serial I/O interface, which is capable of providing an efficient package ball out configuration for a structure in which a DRAM part operating at a low frequency and a serial I/O interface part operating at a high frequency coexist.
[0011] In accordance with an aspect of the present invention, there is provided a multi-port memory device having a serial I/O interface, including: a first package ball out region in which a plurality of balls for a serial I/O interface part are arranged; and a second package ball out region in which a plurality of balls for a DRAM part are arranged.
[0012] In accordance with another aspect of the present invention, there is provided a multi-port memory device having a serial I/O interface, including: a first package ball out region in which a plurality of balls for a serial I/O interface part and a clock part are arranged; and a second package ball out region in which a plurality of balls for a DRAM part are arranged.
[0013] In accordance with a further aspect of the present invention, there is provided a multi-port memory device having a serial I/O interface, including: a first package ball out region in which a plurality of balls for a serial I/O interface part are arranged; and a second package ball out region in which a plurality of balls for a DRAM part and a clock part are arranged.
[0014] When the multi-port memory device includes the high-speed serial I/O interface part and the low-speed DRAM part, the part for supplying power to the high-speed serial I/O interface part is independently separated from the part for supplying power to the low-speed DRAM part, thereby making it easy to configure the power layer in the package.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The above and other objects and features of the present invention will become apparent from the following description of the preferred embodiments given in conjunction with the accompanying drawings, in which:
[0016] FIG. 1 is a diagram of a package ball out configuration of a BGA packaging in a conventional 60-ball DDR2 DRAM;
[0017] FIG. 2 is a diagram of a package ball out configuration of a multi-port memory device having a serial I/O interface in accordance with a first embodiment of the present invention; and
[0018] FIG. 3 is a diagram of a package ball out configuration of a multi-port memory device having a serial I/O interface in accordance with a second embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0019] A multi-port memory device in accordance with exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[0020] FIG. 2 is a diagram of a package ball out configuration of a multi-port memory device having a serial I/O interface in accordance with a first embodiment of the present invention.
[0021] The package ball out configuration in accordance with the first embodiment of the present invention includes a first package ball out region 100 and a second package ball out region 200 , which are arranged at the left and right sides of a vertical center line, respectively.
[0022] Balls 110 for a serial I/O interface part and balls 150 for a clock interface part are arranged in the first package ball out region 100 , and balls for a DRAM interface part are arranged in the second package ball out region 200 .
[0023] In the first package ball out region 100 , the balls 110 for the serial I/O interface part include serial data balls 111 and serial power/ground balls 112 . The serial data balls 111 are used for serial data communication TX 0 +/TX 0 −, RX 0 +/RX 0 −, TX 1 +/TX 1 −, RX 1 +/RX 1 −, TX 2 +/TX 2 −, RX 2 +/RX 2 −, TX 3 +/TX 3 − and RX 3 +/RX 3 −. The serial power/ground balls 112 are used to supply power voltage VDDQ and ground voltage VSSQ to the serial data balls 111 .
[0024] The balls 150 for the clock interface part include clock interface balls 151 and clock power/ground balls 152 . The clock interface balls 151 are used to transfer clock signals CK and /CK, and the clock power/ground balls 152 are used to supply power voltage VDDA and ground voltage VSSA to the clock interface balls 151 .
[0025] In the package ball out configuration of FIG. 2 , the first package ball out region 100 having the power/ground balls VDDQ and VSSQ of the high-speed serial I/O interface is independently separated from the second package ball out region 200 having the power/ground balls VDD and VSS of the low-speed DRAM part. This makes it easy to configure the power layer of the package.
[0026] In addition, the serial data balls 111 are arranged in a differential structure (TX+/TX−, RX+/RX−) for data I/O operation. The data I/O parts of the serial I/O interface are separated into the transmit pins (TX+, TX−) and the receive pins (RX+, RX−) in each port. Therefore, the stability of the data I/O operation can be secured. That is, because TX 0 +/TX 0 −, RX 0 +/RX 0 −, TX 1 +/TX 1 −, RX 1 +/RX 1 −, TX 2 +/TX 2 −, RX 2 +/RX 2 −, TX 3 +/TX 3 − and RX 3 +/RX 3 − are separately arranged, the loads of the I/O package ball out can be equal to one another.
[0027] FIG. 3 illustrates a package ball out configuration of a multi-port memory device having a serial I/O interface in accordance with a second embodiment of the present invention.
[0028] The package ball out configuration in accordance with the second embodiment of the present invention includes a first package ball out region 300 and a second package ball out region 400 , which are arranged at the left and right sides of a vertical center line, respectively.
[0029] Balls 310 for a serial I/O interface are arranged in the first package ball out region 300 . Balls 450 for a clock interface part and balls 410 for a DRAM interface part are arranged in the second package ball out region 400 . Since the package ball out configuration of FIG. 3 is different from that of FIG. 2 only in terms of the arrangement of the balls 450 for the clock interface part, its detailed description will be omitted for conciseness.
[0030] As described above, the power layer of the package can be easily configured by separately arranging the high-speed serial I/O interface part and the low-speed DRAM part. Moreover, the data I/O configuration of the independent serial I/O interface part is separately arranged, thereby securing the data stability.
[0031] The present application contains subject matter related to Korean patent application No. 2006-33049, filed in the Korean Intellectual Property Office on Apr. 12, 2006, the entire contents of which are incorporated herein by reference.
[0032] While the present invention has been described with respect to certain preferred embodiments, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the scope of the invention as defined in the following claims. | A multi-port memory device includes a first package ball out region in which a plurality of balls for a serial I/O interface part are arranged; and a second package ball out region in which a plurality of balls for a dynamic random access memory (DRAM) part are arranged. | 7 |
FIELD OF INVENTION
The present invention relates to novel alkyl polyglycoside maleic acid esters and corresponding copolymers useful in adhesives, coatings and other applications. More particularly, it relates to sugar based vinyl monomers and to copolymers useful in repulpable and adhesives.
BACKGROUND OF THE INVENTION
Polymeric adhesives and paper coatings are used in many disposable packaging applications. Numerous adhesives and glossy coatings are used in the packaging of products such as salt, sugar, tea, coffee and bottle labels, etc. All of these products, and numerous other packaging materials end up for the most part in municipal solid waste (MSW) streams in landfills. Paper and paperboard represent a significant component (˜35% by volume) of the MSW stream and efforts are underway to recycle certain streams and compost others. These largely cellulosic packaging materials should be compatible with composting or paper recycling operations.
With the rising cost of virgin fiber and the increased demand for wastepaper, the pressure is on to re-use more and more contaminated wastepaper. As a result, contaminant removal, which is essential to convert wastepaper into a reusable fiber, is one of the most important factors influencing the economics of the recycling operation, since this has a direct bearing on the yield of reusable fiber from wastepaper and its total cost. Old newsprint (ONP) is the most abundant used paper fiber source, and is most commonly used for the production of recycled paper. Efficient removal of the ink from ONP can be accomplished only by incorporating about 25 to 40% of old magazine (OMG). The OMG contains clays and mineral particles that facilitate the removal of the ink by a flotation de-inking process. The introduction of OMG also improves fiber strength and brightness levels of the recycled fiber. On the other hand, the incorporation of OMG in the recycling process introduces polymer residues from the adhesives and coatings used to manufacture the magazines.
To benefit the environment, adhesives and other polymeric resins used in paper and paperboard applications should be repulpable and not interfere with the recycling process. In addition, they should be biodegradable and have the required cost and performance characteristics to compete effectively in the market place.
Various natural adhesives (starches, dextrins, etc.) and derivatives of natural products which are biodegradable and have adhesive properties, such as carboxymethyl cellulose, amylose from starch, and casein from milk find uses in adhesive applications. Natural adhesives are used in packaging applications, but they continue to be displaced by synthetics primarily due to performance. Although they are biodegradable and compostable, these natural adhesives cause a problem in paper recycling because they are water soluble, and thus are concentrated in the closed-system water loop of the repulping process where they build up in the initial section of the dryer and on the dryer felts.
With the growing trend of mills re-using their process water, it is becoming as important to effectively remove all contaminants from the pulp flow as it is to remove them totally from the water system in an effort to prevent the accumulation of colloidal impurities. The preferred approach to achieve this requirement is to separate the contaminants at the earliest possible step in the process, but the inherent sticky nature of currently used hot melts and pressure-sensitive adhesive products makes this very difficult. The reduction of water consumption (zero-discharge) with closed water recirculation systems causes reagglomeration of dispersed adhesives resulting in deposits known as "stickiest" on dryer walls and on the polyester `wire`, i.e. the felt on which the recycled paper is deposited. This occurs at very high speeds, and once adhesive residues begin to deposit, build-up occurs exponentially leading to costly mill shut downs.
The residues from adhesives and other polymeric materials currently used in glossy paper coatings, sizing agents, toner particles, etc., which lead to the formation of "stickiest", can have a major impact on the smooth operation and the economics of a paper recycling process. Currently, centrifugal cleaning and fine screening are regarded as the best systems for stickies removal, but these are costly and inefficient.
The commercially available adhesives which are characterized as being repulpable are generally water soluble synthetic adhesives which still cause stickies problems in closed loop recycling mills. Therefore, there is still a need for repulpable adhesives and coatings that match the performance and cost of the predominantly synthetic products now being used. A truly `repulpable` polymer is a polymer which does not persist as "stickies" in a paper recycling process, but which can be quantitatively removed from the process using conventional equipment found in a paper recycling mill.
BRIEF SUMMARY OF THE INVENTION
It is an object of the present invention, to provide novel copolymers which are useful in biodegradable, repulpable adhesives, coatings, sizing agents, toners, retention aids and related products used in paper and paperboard applications, in wood gluing and other packaging applications.
The copolymers of the present invention are copolymers of alkyl polyglycoside maleic acid esters and vinyl monomers. The novel copolymers of the present invention may be represented by the following formula: ##STR1## wherein Glu is a saccharide moiety which is derived from α-D-glucose (dextrose), fructose, mannose, galactose, talose, gulose, allose, altrose, idose, arabinose, xylose, lyxose, ribose, or mixtures thereof, or which can be derived by hydrolysis from the group consisting of starch, corn syrups-or maltodextrins, maltose, sucrose, lactose, maltotriose, xylobiose, mellibiose, cellobiose, raffinose, stachiose, levoglucosan, and 1, 6-anhydroglucofuranose. R 1 and R 2 are substituent groups of a vinyl monomer or mixture of vinyl monomers, wherein said vinyl monomer or mixture of vinyl monomers is selected from the group consisting of vinyl acetate, ethyl hexyl acrylate, butyl acrylate, ethyl acrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate, lauryl acrylate, methyl methacrylate, methacryclic acid, acrylic acid, and other acrylates or mixtures of different acrylate monomers, ethylene, 1, 3-butadiene, styrene, vinyl chloride, vinylpyrrolidinone, and other vinyl monomers, or mixtures thereof, R is selected from the group consisting of a C1 to C30 alkyl or a mixture thereof, more preferably a C3 to C8 alkyl or a mixture thereof, R'" is selected from the group consisting of a C1 to C30 alkyl or a mixture thereof, or a hydrogen, preferably a C8 to C18 alkyl or a mixture thereof, and most preferably a C12 to C14 alkyl or a mixture thereof; n is an integer ranging from 0 to 10, its average value ranging from 0.3 to 1; thus, <n+1>=1.3 to 2 corresponds to the average degree of oligomerization of the alkyl polyglycoside; x and y are integers ranging from 0 to 3 or from 0 to 4, where the maximum value of 3 or 4 for x and y equals the number of hydroxyls on the Glu moiety, but not both x and y are zero, and, p and q are integers ranging from 0 to 1000, but not both p and q are zero. The lines indicate continuing polymer chains.
The copolymers of the present invention are useful in adhesives, coatings, sizing agents, toners, retention aids and related polymer resins in paper and paperboard applications, in wood gluing and other packaging applications.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 summarizes the relative efficiencies of the various contaminant removal processes that can be used in paper recycling as a function of particle size.
DETAILED DESCRIPTION OF THE INVENTION
The copolymers are prepared from alkyl polyglyosides maleic acid esters and conventional vinyl monomers.
The maleic acid esters of APG's (designer sugar molecules) have a polymerizable double bond and they are prepared by the reaction of an APG, maleic acid anhydride and alcohol. The preparation of the APG's and the maleic acid esters can be illustrated as follows: ##STR2## in which R" is selected from the group consisting of C1 to C30 alkyl groups or mixtures thereof, and all other symbols are as previously defined.
As-illustrated above, an aldose sugar, such as α-D-glucose, is first reacted at the anomeric C1 carbon position with a primary alcohol or a mixture of primary alcohols (R--OH), to form an alkyl polyglycoside (APG). The reaction is preferably conducted in the presence of an acid catalyst, such as concentrated sulfuric acid, in accordance with known methods. The excess alcohol may be removed by vacuum distillation or by other physical separation techniques, such as extraction. The preparation of APG's is described in U.S. Pat. No. 3,839,318.
When the APG is reacted with maleic acid anhydride at temperatures from about 55° C. up to 120° C. under anhydrous and homogeneous reaction conditions a primary alcohol or a mixture of primary alcohols (R'-OH), having an alkyl group of preferably a C3 to C8 or a mixture thereof, can be added during this step as a solvent for the APG. When the alcohols R--OH and R'-OH are the same, partial removal of excess alcohol suffices in the reaction step to form the APG. The R'-OH alcohol is a reactive solvent which, upon reaction with maleic acid anhydride, provides an alkyl maleic acid monomer. Thus, this alcohol acts as a solvent during the maleation step, but is itself reacted quantitatively with maleic anhydride to provide a copolymerizable solvent/monomer in which the maleated APG is soluble. In place of the primary alcohol solvent, a dialkyl maleic ester can be used as a copolymerizable solvent, having alkyl groups of preferably a C1 to C18 alkyl or a mixture thereof, more preferably a C1 to C8 alkyl or a mixture thereof, and most preferably a C4 alkyl.
Following the maleation reaction, a primary alcohol (R"OH) or a mixture of primary alcohols, having an alkyl group of preferably C1 to C18 or a mixture thereof, more preferably C8 to C18 alkyl or a mixture thereof, and most preferably a C12 to C14 alkyl or a mixture thereof, can be added to esterify any residual unreacted maleic anhydride, a portion or all of the free acid groups of the alkyl polyglycoside maleic acid and of the alkyl maleic acid, if present.
The alcohols for use in the above process are those hydroxyl-functional organic compounds capable of alkylating a sacchride in the "1" position. The alcohols can be naturally occuring, synthetic or derived from natural sources.
The molar stoichiometry of maleic acid anhydride to APG is controlled to be more than one to afford incorporation of the sugar molecules into the polymeric structure.
The copolymers of the present invention are prepared by reacting the maleic acid esters of an APG with conventional vinyl monomers, such as vinyl acetate, ethyl hexyl acrylate, butyl acrylate, ethyl acrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate, lauryl acrylate, methyl methacrylate, methacrylic acid, acrylic acid, and other acrylates or mixtures of different acrylate monomers, ethylene, 1, 3-butadiene, styrene, vinyl chloride, vinylpyrrolidinone, and other vinyl monomers or mixtures thereof. Other suitable vinyl monomers include-those disclosed in Table II/1-11 in Polymer Handbook, J. Bandrup, 3rd Ed. John Wiley & Sons Inc., (1989).
The use of divinyl sugar monomers produces random copolymers when reacted with conventional vinyls monomers. Randomness in the copolymers can be attained by using a monomer pre-emulsion which is slowly added to the polymerizing mixture. This so-called starve-fed copolymerization process is a process well-known to those skilled in the art.
The reaction of a maleic acid ester of an APG with a vinyl monomer to form a copolymer of the present invention may be illustrated as follows: ##STR3##
The copolymers of the present invention are waterborne dispersions which contain no volatile organic compounds (VOC's) and incorporate `designer sugar molecules` along with conventional vinyl monomers. The conventional vinyl monomers provide the design flexibility common to current commercial synthetic copolymer resins, while the `designer sugar molecules` provide the properties of repulpability and biodegradability.
The APG's are made from renewable resources, namely, sugars such as monosaccharides, oligosaccharides or polysaccharides. The most preferred sugar is dextrose (α-D-glucose) which is derived from corn.
The maleic acid esters of the APG's which are prepared by reacting an APG with maleic acid anhydride and subsequently with alcohol, are low-cost monomers which contain a polymerizable double bond.
The most preferred APG's for use in the present invention are those containing lower alkyl groups of four to six carbons (butyl to hexyl) or mixtures thereof, because such APG's are viscous liquids which can be readily reacted with maleic acid anhydride in the absence of a solvent. The use of butyl to hexyl polyglycosides, which are viscous liquids that can be readily reacted with maleic anhydride in the absence of a solvent, is a unique advantage of this invention.
Whereas unmodified sugar is highly polar and insoluble in most organic solvents or monomers, the APG is a viscous liquid or solid which is soluble in the organic phase to facilitate reaction with maleic acid anhydride. Above its melting point of about 55° C., maleic acid anhydride is a liquid which is miscible with the APG. This avoids the use of a solvent that would contribute to VOC's.
In addition, common sugars such as α-D-glucose, or the mono- and disaccharides, oligosaccharides and polysaccharides, generally contain appreciable levels of water (typically 8 to 12 weight %). In contrast, the APG's, which are prepared by the method described above, have a very low moisture content (typically less than 1 weight %). This is important because maleic acid anhydride is readily hydrolyzed by water to produce maleic acid as an undesired byproduct. Thus, an APG can be reacted with maleic anhydride at temperatures from about 55° C. up to 120° C. under anhydrous and homogeneous reaction conditions.
APG's having higher alkyl groups also can be used in accordance with the present invention, in combination with a primary alcohol or a mixture of primary alcohols, having an alkyl group of preferably a C4 to C18 or a mixture thereof, or a dialkyl maleic ester, as a solvent for the APG during the maleation step. The incorporation of an alcohol as a reactive and copolymerizable solvent, or a dialkyl maleic ester as a copolymerizable solvent, to facilitate the use of higher alkyl APG's is another advantage of this invention.
The molar stoichiometry of maleic anhydride to APG is controlled to be more than one to afford incorporation of the sugar molecules into the polymeric structure. The use of maleic anhydride to introduce sugar within the polymeric structure of the APG ester/vinyl copolymer chains, is a unique feature of this invention.
The copolymers are synthetic latex or suspension copolymers which contain sugar-based units that are incorporated within the polymeric structure. This is supported by the-observation that dried films, prepared from latex cast on a glass substrate, were found to be transparent. The bi- or multi-functionality of the sugar-based units permits the introduction of the sugar units within the polymeric structure of the copolymer chains.
The ability to incorporate sugar units into polymeric chains results in copolymers which are susceptible to biodegradation to produce low molecular weight fragments. If enough biodegradable links are introduced into the polymer chains using 10 to 30 mole % of the APG maleic acid ester, the initial biodegradation of these copolymers leads to low molecular weight polyolefin oligomers, which in turn are biodegradable themselves provided they are aliphatic and their molecular weight is below about 1000 g/mole.
Evidence of the biodegradability of the copolymer made in accordance witht he present invention was demonstrated in compost experiments which confirmed that there were increasing levels of biodegradability with increased levels of the AOC maleic acid ester (10 to 30 mole %).
Without being restrictive, it is believed that the copolymers experience an increase in surface energy as they go from a dry state in which they serve as adhesives, to a wet state when they are dispersed in water in the paper recycling process.
As previously mentioned, contaminant removal during paper recycling is of major importance owing to the increased use of closed and semi-closed loop systems in the process water. Thus, there are more problems with contaminants (such as stickies) and other dissolved colloidal substances in paper recycling mills when the process water loop is switched from an open system to a closed system. Adhesive particles can be removed from the process water by a number of different processes including forward and reverse washing, screening and flotation. The size of the contaminant particle determines to some extent the type of removal process to be used.
FIG. 1 summarizes the relative efficiencies of the various contaminant removal processes that can be used in paper recycling as a function of particle size. The narrower the size distribution, the more efficient it becomes to remove contaminants with a given process step of the paper recycling process. Thus one would like to produce an adhesive which desorbs from paper fiber under repulping conditions and is broken down to a particle size range (under shear conditions found in repulpers) in which the particles could be easily removed by one or a combination of several of the contaminant removal processes cited in FIG. 1. For example, for an adhesive particle to be efficiently removed by a flotation process, the particles have to be hydrophobic and in the size range of about 10 to 70 μm.
When levels of 1 to 25 mole percent of the APG maleic ester monomer are used, the copolymers are non-tacky under repulping conditions, and doe not undergo redeposition onto paper fibers. Instead they are broken down to particle sizes amenable to removal by the normal flotation process under the typical shear conditions found in a paper recycling mill.
Without being restrictive, it is believed that the copolymers of the present invention because they have hydrophilic sugar units (APG maleic acid esters) and hydrophobic synthetic units (vinyl monomers), possess the ability to change surface energy in the aqueous repulping process, allowing adhesive residues to be sheared down to fine non-sticky particles in the range of 10 to 70 μm. As a result, these particles can subsequently be mechanically removed during the flotation deinking process, while deposition on wires, dryer felts and surfaces is minimized. Thus, the copolymers of the present invention are non-tacky under repulping conditions, and they do not undergo redeposition onto paper fibers, but are broken down to particle sizes which are amenable to removal by the flotation process in the setting of typical shear conditions found in a paper recycling mill.
EXAMPLE 1
Free-radical emulsion or suspension copolymerizations were conducted with vinyl monomers and APG maleic acid ester monomers. The emulsion polymerizations were carried out in 1 liter, 4 necked, round bottom reaction kettles equipped with overhead mechanical stirrer, a condenser, a monomer pre-emulsion feed inlet, a thermocouple, an initiator solution feed, a nitrogen purge feed, and a nitrogen bubbler. The reaction vessel was charged with distilled water, stirred at 200 rpm, heated by using a water bath controlled at 80±1° C., and purged with nitrogen. Sodium carbonate buffer and ammonium persulfate initiator were dissolved in water and charged to the reactor immediately before the monomer addition was started. Examples of typical polymerization recipes can be found in Table 3.
TABLE 3__________________________________________________________________________Summary of Select Emulsion Copolymerizatins.sup.aExperiment No 317 402 430 625 701 708 724 801__________________________________________________________________________Reactor Charge:Distilled Water 112.5 112.5 159.79 59.52 59.52 59.52 59.52 59.52Na.sub.2 CO.sub.3 0.25 0.25 0.50 0.26 0.26 0.26 0.26 0.26Ammonium Persultate 0.35 0.175 0.35 0.18 0.18 0.i8 0.18 0.18Monomer Pre-Emulsion Feed:Sugar-Based Vinyl Monomer 2 3 4 5 6 6 6 7(SBV) as Prepared InExample No.SBV Monomer 18.15.sup.b 19.37.sup.b 59.27.sup.b 37.78 10.6 19.08 19.6 10.6Butyl Acrylate 0 43.32 65.75 29.37 68.89 37.42 71.55 71.55Methyl Methacrylate 0 43.32 86.98 38.85 26.51 49.5 0 0Vinyl Acetate 87.85 0 0 0 0 0 23.85 23.85Distilled water 35.5 35.5 71 55 55 55 55 55Surfactant 3.47 5.41 13.31 6.66 6.66 6.66 6.66 6.66Initiator Feed:Distilled Water 10 10 30 15 15 15 15 15Ammonium Persulfate 0.5 0.5 3 0.75 0.75 0.75 0.75 0.75wt % SBV Monomer (dry basis) 17.sup.b 18.sup.b 28.sup.b 36 10 18 10 10wt % Solids (aqueous copolymer 40 40 45 45 45 45 45 45emulsion)__________________________________________________________________________ .sup.a Unless otherwise noted all values are in grams .sup.b Includes alkyl maleate monomer used as a solvent in the synthesis ot the SBV monomer
Monomer pre-emulsions or suspensions were prepared as follows. An APG maleic acid ester monomer composition, for which the preparation is given in subsequent Examples (with corresponding-Example numbers given in Table 3), was added to conventional acrylate and/or vinylacetate monomers and mixed thoroughly. The mixture was subsequently added slowly to a distilled water and surfactant solution, while stirring continuously, to form an oil in water emulsion. The monomer pre-emulsion feed was placed in a 500 mL, 3 necked, round bottom flask. Two of the openings were used for a nitrogen purge inlet and outlet and the third neck was fitted with a tube that drew the feed out by an LMI Milton Roy metering pump and into the polymerization vessel. The total monomer feed time was 2.5 hours. The monomer emulsion or suspension was continuously stirred using a magnetic stirbar throughout the feeding process and no phase separation was noticed. A distilled water and ammonium persulfate initiator solution was added continuously to the polymerization reactor for 3.5 hours using a Harvard Apparatus syringe pump. Just before addition of the monomer pre-emulsion was started, the nitrogen purge to the polymerization vessel was shut off, the outlet to the nitrogen bubbler was closed, and an 18 gauge needle was introduced in the rubber septum to maintain atmospheric pressure in the polymerization vessel during the addition of monomer pre-emulsion. This ensured that a nitrogen head was maintained and that the product did not crust on the wall of the reactor vessel. During the polymerization, 1 mL samples were taken for pH and % solids data as a function of time. The % solids were converted into % conversion data which showed the overall conversion and confirmed that starve-fed conditions were achieved. The appearance, color, scent, viscosity, stability, reflux, and bath and reactor temperatures were also recorded throughout the polymerization reaction. The latex was heated for an additional 4.5 hours after all of the initiator had been added. At the end of the 8 hour polymerization period, the reaction mixture was cooled and filtered through a 100 mesh filter. Stable copolymer products were obtained with narrow particle size distributions within the range of 100 to 1000 nm. The usual variations of particle size with soap and monomer concentrations applied. Typical monomer conversions were 95 to 100%.
EXAMPLE 2
A maleic acid ester of an APG was prepared as follows. To a 1 L erlenmeyer flask, containing a magnetic stir bar, was added 185.1 g anhydrous n-butanol (Aldrich, 99.8%), 36.1 g n-octanol (Aldrich, 99+%), and 2.0 g deionized water. To the stirred mixture, 0.184 g (100 mL) of concentrated sulfuric acid (J. T. Baker, 96.6%) was added using a 1 mL glass syringe. This mixture was added to a 500 mL three necked round bottom flask containing 50.0 g of anhydrous α-D-glucose (Aldrich, 96%) and a concave magnetic stir bar. The flask was fitted with a thermocouple probe, a dry air intake, and a 25 mL Barrett receiver on which two glass condensers were mounted, which were connected to a gas bubbler. The condensate collection side of the Barrett receiver was filled with n-heptane, and the gas flow-through side was wrapped in cotton wool for the purpose of insulation. Dry air, passed over a 10 inch column filled with dry molecular sieves and Drierite, was passed through the liquid phase in the round bottom flask. The flask was heated for 4 hours at about 95° to 100° C. using a temperature controlled oil bath. Approximately 12 mL of condensate water was collected in the Barrett receiver as a result of glucose oligomerization reaction and the aldol condensation reaction to give alkylation at the C1 position. The white suspension of sugar particles disappeared as the reaction from glucose to APG proceeded until a clear solution was obtained. This demonstrated that the APG is soluble in the alcohol. The resulting APG solution was colorless, indicating that byproduct formation of colored bodies, such as furfurals, was minimized.
The APG solution was neutralized with 2.0 mL of a 7.30 g/100 mL solution of sodium hydroxide in deionized water. The excess butanol was removed by vacuum distillation at 70° to 105° C. and 22 to 25 inches of Hg. Analysis of the distillate by 500 MHz 1 H nuclear magnetic resonance (NMR) spectroscopy showed that no detectable levels of octanol had distilled over. The degree of oligomerization, DP n , of the APG was determined to be 1.65 by 500 MHz 1 H NMR.
To a 100 mL addition funnel wrapped with heating tape, 71.35 g maleic anhydride (Sigma, 99+%) was added, a thermocouple was inserted, and the funnel was heated to 60° to 85° C. until all the maleic anhydride powder was melted. The liquid maleic anhydride was added over a period of about 10 minutes to the APG/octanol mixture which was at an initial temperature of about 100° C., resulting in an exotherm up to about 120° C. After 1 hour, the reaction was cooled to 500° C., and 162.8 g of n-hexanol (Aldrich, 98%) and about 50 g of dry molecular sieves was added for the esterification of free maleic acid groups. The esterification reaction was allowed to proceed for 12 hours at approximately 120° C. The reaction product was cooled and divided into two equal portions; to one of the portions 0.64 g of the titanium-based esterification catalyst "TYZOR" TBT Titanate (Du Pont Chemicals) was added; the mixture was reheated and allowed to react for an additional 12 hours. Excess hexanol was removed using a rotary evaporator. Samples were taken for analysis by NMR and thin layer chromatography, which confirmed the formation of APG, APG-maleic acid/octyl maleic acid mixture, and the APG-maleic/octyl maleic ester product in the respective reaction steps. 500 MHz 1 H NMR analysis of the key fractions, which were eluted using silica gel (Aldrich, Grade 923, 100-200 mesh) column chromatography, further confirmed the formation of the APG-maleic acid ester product. The pH of the APG-maleic acid/octyl maleic acid mixture was about 1.8, while the pH of the APG-maleic/octyl maleic ester product was 6.3 and 6.8 for the two fractions prepared in the absence and in the presence of the esterification catalyst, respectively.
EXAMPLE 3
The procedure given in Example 2 was followed. The reaction time to form the APG was 3 hours, 20 minutes. The DP n of the APG was determined to be 1.67. Instead of 71.35 g maleic anhydride, 75.90 g was used, and 200.0 g of anhydrous n-butanol was used in the esterification step in place of n-hexanol; 0.75 g of the "TYZOR" TBT catalyst was used, and 89 g of dry basic alumina in place of molecular sieves. Excess butanol was removed using a rotary evaporator. Samples were taken for analysis by NMR and thin layer chromatography, which confirmed the formation of APG, APG-maleic acid/octyl maleic acid mixture, and their partial esterification products. The pH of the APG-maleic acid/octyl maleic acid mixture was about 1.8, while the pH of the final product was 2.6.
EXAMPLE 4
A maleic acid ester of an APG was prepared as follows. To a 1L erlenmeyer flask, containing a magnetic stir bar, was added 411.4 g n-butanol (Mallinckrodt; 99.7%, 0.03% H 2 O), and to the stirred mixture, 0.368 g (200 mL) of concentrated sulfuric acid (J. T. Baker, 96.6%) was added using a 1 mL glass syringe. This mixture was added to a 1L three necked round bottom flask containing 111.3 g of α-D-glucose (containing 8.8% water) and a concave magnetic stir bar. The flask was fitted with a thermocouple, a dry air intake, a Barrett receiver and two glass condensers as described in Example 2. The flask was heated for 3 hours, 25 minutes at about 95° to 102° C. Approximately 18 mL of condensate water was collected in the Barrett receiver. The white suspension of sugar particles disappeared as the reaction from glucose to APG proceeded until a clear solution was obtained. The resulting APG solution was colorless. The APG solution was neutralized with 1.0 mL of a 29.2 g/100 mL solution of sodium hydroxide in deionized water. The DP n of the APG was determined to be 1.59 by 500 MHz 1 H NMR. 77.5 g of dibutyl maleate (Aldrich, 99.7%) was added to the APG-butanol solution. The excess butanol was removed by vacuum distillation at 75° to 105° C., and 26 to 29 inches of Hg. The APG was soluble in dibutyl maleate at temperatures above about 95° C. Analysis of the distillate by 1 H NMR showed that no detectable levels of dibutyl maleate had distilled over.
To a 250 mL addition funnel wrapped with heating tape, 110.24 g maleic anhydride (Sigma, 99+%) was added, a thermocouple was inserted, and the funnel was heated to 60° to 85° C. until all the maleic anhydride powder was melted. The liquid maleic anhydride was added over a period of about 13 minutes to the APG/dibutyl maleate mixture which was at the initial temperature of about 106° C., resulting in an exotherm up to about 120° C. The total reaction time was 4 hours. Samples were taken for analysis by NMR and thin layer chromatography, which confirmed the formation of APG, and the complete conversion of APG to maleated APG in the respective reaction steps.
EXAMPLE 5
The procedure given in Example 4 was followed using 411.6 g n-butanol (Aldrich, anhydrous, 99.8%), and 2.0 g additional water, 100.24 g anhydrous α-D-glucose. The APG reaction time was 3 hours, and the DP n of the APG was determined to be 1.66. No dibutyl maleate was added prior to distillation of the alcohol. After removal of the excess butanol, the butyl glycoside thus produced was a viscous liquid. For the maleation reaction, 109.89 g maleic anhydride was used, which was added in less than 1 minute to facilitate stirring. The reaction temperature at the start of the reaction was 77° C., and an exotherm was observed up to about 117° C. The total reaction time was 4 hours. Samples were taken for analysis by NMR and thin layer chromatography, which confirmed the formation of APG, and the complete conversion of APG to maleated APG in the respective reaction steps.
EXAMPLE 6
The procedure given in Example 5 was followed using 411.8 g n-butanol (Aldrich, anhydrous, 99.8%), 2.0 g additional water, and 100.02 g anhydrous α-D-glucose. The APG reaction time was 3 hours, and the DP n of the APG was determined to be 1.64. For the maleation reaction, 108.58 g maleic anhydride was used.
EXAMPLE 7
The procedure given in Example 5 was followed using 411.4 g n-butanol (Aldrich, anhydrous, 99.8%), 2.0 g additional water, and 100.1 g anhydrous α-D-glucose. The APG reaction time was 3 hours. For the maleation reaction, 109.0 g maleic anhydride was used. The reaction time for the maleation was 2 hours. Following the maleation reaction, the intermediate product was divided into three portions to which 6, 23 and 76% of NEODOL R 23 (a C 12 -C 13 mixture of alcohols, Shell Chemical Co., MW ave =193) and 50 g of dry basic alumina were added for esterification at 120° C. for the 23 and 76% NEODOL fractions. The reaction time was about 4 hours for the 6% NEODOL fraction and about 15 hours for the other two fractions.
EXAMPLE 8
The novel copolymers of the present invention are nontacky under repulping conditions, they do not undergo redeposition onto paper fibers and they are broken down to particle sizes which are amenable to removal by the floatation process under typical shear conditions found in a paper recycling mill.
To illustrate the unique repulpability of the copolymers provided herein, the following test procedure was used. To 1L of a caustic solution (NaOH, pH=10), 4 to 5 grams of a dry adhesive polymer film was added, and the mixture was blended at 65° C. for 5 minutes using a Waring Blender at the grate setting. Samples were taken from the foam and liquid phase, and examined under a phase contrast microscope at 100× and 1000× magnifications. Examination of the foam showed that the foam was enriched in adhesive particles in the size range of 10 to 70 μm. This served as a convenient method for examining the mass transfer of adhesive particles between the liquid and foam phases, a process well known to those skilled in the art of flotation deinking.
Photomicrographs were taken at both magnifications for various adhesive compositions provided in this invention, and their performance was compared with control adhesive compositions which contained no sugar-based vinyl monomer, as described in Table 4.
TABLE 4______________________________________Composition of Various Adhesives used inTesting Repulpability.sup.aSample No. 1 2 3 4______________________________________Adhesive Type.sup.b PSA non PSA PSA Non PSA Control ControlSugar-Based Vinyl Monomer 0 0 10 10(SBV)Butyl Acrylate (BA) 72 43 65 39Methyl Methacrylate (MMA) 28 57 25 51BA/(BA + MMA) Ratio 0.72 0.43 0.72 0.43______________________________________ .sup.a All values are expressed in % w/w .sup.b PSA = pressure sensitive adhesive
Photomicrographs (at 100× magnification) of the liquid phase for Sample no. 3 (Table 4), which is an example of a pressure-sensitive adhesive made with a monomer of the present invention, showed particles in the range of 20 to 200 um in diameter. In the control experiment, a dry adhesive film was treated in the same manner, using a pressure sensitive adhesive of similar composition which did not contain a sugar-based monomer (Sample no. 1, Table 4). In contrast to Sample no. 3, the dry adhesive film of Sample no. 1 became sticky in the blender, and no-small particles were observed under the microscope at either 100× or 1000× magnification for this control sample. These results demonstrate that the adhesive which was copolymerized using the APG maleic acid ester monomer is more susceptible to break down to particles under the shear forces generated in the blender.
Similar results were observed for a non-pressure sensitive adhesive sample (Sample no. 4). This copolymer also sheared down to small particles, which were in the range of 10 to 100 μm. The non-pressure sensitive control (Sample no. 2) was sheared down to particles greater than 100 μm. This size range is considerably larger than that was observed for Sample no's 3 and 4, which employed copolymer of the present invention.
The results of Example 8 illustrate that pure pressure sensitive or non pressure sensitive adhesive resins containing the copolymers of the present invention, have the unique property of being broken up into small particles in a blender even in the absence of paper fiber.
EXAMPLE 9
To better simulate the conditions found in a paper recycling mill, where such adhesives are present as coatings on paper, a model repulping experiment was conducted. This model experiment characterizes the fate of such adhesive residues in the presence of paper fiber. A variation of Example 8 was conducted to test the effects of shear conditions on model repulping experiments, in which such adhesives are present as coatings on Kraft paper.
The conditions of the experiment were as follows: 4.0 grams of wet adhesive (latex) (Sample No. 3) were applied to a sheet of blotter paper (15 grams). This preparation was dried overnight and subsequently cut into 1.5 cm×1.5 cm squares. The paper squares were added to 500 mL of water, adjusted to pH=10 with NaOH, and blended in a Waring Blender for 5 minutes at 65° C. The resultant pulp slurry was examined under a phase contrast microscope at 100× magnification and 1000× magnification. The adhesive particles were shown to range in size from 3 to 30 μm. This represents a shift to lower particle size as compared to the particle size range in the repulping experiments where no Kraft fiber was present. This is due to the increase in effective shear forces generated in the blender when pulp fibers are present.
Adhesive particles were observed to adhere to the edge of air bubbles for samples taken from the foam or aqueous layers. This was routinely observed and demonstrates that the adhesive particles are relatively hydrophobic in nature. Hydrophobicity is a basic requirement for physisorption of particles onto an air bubble, which is well known to those skilled in the art.
These results demonstrate that adhesives containing the copolymers of the present invention are susceptible to breakdown by the shear forces generated in the blender, and that the size distribution of adhesive residues is in the range which is amenable to removal by flotation.
The products of the present invention provide new sugar-based copolymers utilizing agricultural resources which can be returned to those resources in an environmentally sound manner. The invention provides new polymeric materials for environmental compatibility. This was achieved by designing and engineering repulpable and biodegradable materials that are polymeric, yet break down under appropriate process conditions. Thus, the copolymers of the present invention facilitate the recycling of paper because they are sheared down into small particles in the paper recycling process. This allows the adhesive residues to be removed the process water via the flotation deinking facility of a paper recycling mill. On the other hand, for disposable packaging applications, these sugar-based vinyl copolymers can be assimilated by microorganisms under composting conditions to help convert biodegradable waste into compost.
The invention has been described in an illustrative manner, and it is to be understood the terminology used is intended to be in the nature of description rather than of limitation.
Many modifications and variations of the present invention are possible in light of the above teachings. Therefore, it is to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described. | Copolymers prepared from novel alkyl polyglycoside maleic acid esters and vinyl monomers are biodegradable and repulpable and are useful in adhesives, coatings, sizing agents, toners, retention aids and related polymer resins in paper and paperboard applications, in wood gluing, packaging and other applications. | 3 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an electrostatic ink jet recording head which accomplishes recording to a recording medium by using charged particulate materials in ink, and more particularly to an electrostatic ink jet recording apparatus which prevents precipitation of charged particulate material in ink.
2. Description of the Prior Art
An electrostatic ink jet recording apparatus according to the prior art, as disclosed in PCT Publication number WO 93/11866, has an electrostatic ink jet recording head and a counter electrode arranged behind recording paper. The counter electrode is provided for generating an electric field between the recording paper and the ink jet recording head. The ink jet recording head has an ink chamber for temporarily storing ink liquid supplied from an ink tank or the like. An ejection electrode is formed at an end of the ink chamber and driven when the ink is ejected. The tip of that ejection electrode is opposite to the counter electrode. The ink liquid in the ink chamber is fed by its own surface tension to the tip of the ejection electrode, where an ink meniscus is thereby formed.
The ink liquid used with that ink jet recording head contains charged particulate material for coloring. While the charged particulate material is electrified in a positive polarity by a Zeta potential, the ink liquid maintains electric neutrality when no voltage is fed to the ejection electrode. The polarity of the Zeta potential is determined by the characteristic of the charge particulate material.
When a voltage of the positive polarity is fed to the ejection electrode, the positive potential of the ink liquid is enhanced. The charged particulate material is caused by an electric field working between the ejection electrode and the counter electrode to shift in the ink liquid toward the tip of the ejection electrode. The charge particulate material having reached the tip of the ejection electrode is strongly drawn toward the counter electrode by the electric field working between the tip of the ejection electrode and the counter electrode. When the Coulmob force between the charge particulate material at the tip of the ejection electrode and the counter electrode substantially surpasses the surface tension of the ink liquid, an agglomeration of the charge particulate material accompanied by a small quantity of liquid flies from the tip position of the ejection electrode toward the counter electrode, and adhere to the surface of the recording medium. As the agglomeration of the charge particulate material is caused by the application of a voltage to the ejection electrode to successively fly from the tip of the ejection electrode, printing is accomplished.
However, the charge particulate material of the ink liquid used in the electrostatic ink jet recording head is readily precipitated by gravity, and therefore does not distribute evenly in the ink chamber. As a consequence, charge particulates are not steadily supplied to the tip of the ejection electrode, and the quantity of the charge particulate material in the agglomeration flying from the ink ejecting position is inconstant. Accordingly, there is the problem of difficulty to accomplish steady printing.
Furthermore, when the ink liquid in the ink chamber is to be shifted toward the tip of the ejection electrode only by the ejection electrode and the counter electrode, precipitation of the charge particulate material extends the shifting time, making it difficult to achieve high-speed printing.
SUMMARY OF THE INVENTION
An object of the present invention is to eliminate the aforementioned disadvantages of the prior art, and in particular to provide an electrostatic ink jet recording apparatus capable of printing steady images.
Another object of the invention is to provide an electrostatic ink jet recording apparatus capable of high-speed printing.
According to the invention, there is provided an electrostatic ink jet recording apparatus comprising a head body and a counter electrode. The head body has an ink chamber for holding an ink liquid such as a charge sensitive ink containing charged particulate material. An ejection port is provided at one end of the head body and connecting to the ink chamber. An ejection electrode is arranged near the ejection port and fed with an ejection voltage of the same polarity as the charge characteristic of the charged particulate material. The counter electrode is arranged opposite to the ejection port via a recording medium and has a necessary electric potential for electric attraction of the charged particulate material. A pair of stirring electrodes is arranged in the direction reverse to that of the gravity of the ink chamber and fed with a stirring voltage for shifting the charge particulate material at least in the direction reverse to the direction of gravity. A voltage generating circuit is provided for generating the ejection voltage and the stirring voltage, the latter being generated before the generation of the ejection voltage.
According to the invention, the stirring voltage for generating an electric field to shift the charged particulate material in the direction reverse to that of gravity is fed to the stirring electrodes. Moreover, that stirring voltage is generated earlier than the ejection voltage. As a result, the precipitation of toner particulates is prevented before the ejection of ink, and the overall concentration of toner particulars in the ink liquid in the ink chamber is uniformized. It is thereby made possible to supply a constant quantity of toner particulates to the tip electrode section of the ejection electrode and accordingly to achieve high-quality prints free from irregularity of recording.
When one of the stirring electrodes comes into contact with the charge sensitive ink liquid, the electric potential of the ink liquid can be controlled so as to reach a sufficient level for the accomplishment of ejection, enabling the charge characteristic of the charged particulate material to be fully drawn upon. In this instance, the polarity of the D.C. voltage of the stirring electrode in contact with the ink liquid (stirring offset voltage) is made identical to the charge polarity of the charged particulate material.
Furthermore, when a stirring A.C. voltage is fed to the stirring electrodes besides the stirring offset voltage, the toner particulates can be stirred vigorously and quickly by the action of the alternating electric field.
In addition, the stirring electrodes, if they function when no pulse voltage is fed to the ejection electrode, not only are prevented from giving any adverse effect on ejection, but also can stabilize the quantity of toner particulates in the agglomerations, irrespective of the image to be recorded, by stirring consecutively during printing, and can thereby give prints of high quality.
There are two stirring electrodes: a first stirring electrode arranged in the direction of gravity of the ink chamber and provided with the stirring offset voltage, and a second stirring electrode arranged in the direction reverse thereto. Here, if the first stirring electrode is arranged also in a direction reverse to the direction of ink ejection, the charged particulate material can be shifted not only in the direction reverse to the direction of gravity but also in the direction of ink ejection. This arrangement enables the charged particulate material to be rapidly shifted in the direction of ink ejection.
Furthermore, the electrostatic ink jet recording apparatus according to the present invention may have an electrophoretic electrode apart from the stirring electrodes. To the electrophoretic electrode is supplied an electrophoretic voltage for shifting the charged particulate material toward the ejection hole by electrophoresis. In this case, the stirring voltage is generated before the generation of the electrophoretic voltage and of the ejection voltage.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan of an electrostatic ink jet recording apparatus, which is a first preferred embodiment of the present invention, partly shown cross-sectionally;
FIG. 2 shows a cross section on the X--X line in FIG. 1;
FIG. 3 illustrates the drive circuit for the ink jet recording head for the electrostatic ink jet recording apparatus of FIG. 1;
FIG. 4 shows an expanded cross-sectional view of a state in which toner particulates have precipitated in the ink chamber;
FIG. 5 shows a cross-sectional view of the state of toner particulates in the ink chamber when a voltage is applied to the stirring electrodes;
FIG. 6 is a timing chart illustrating the operation of the drive circuit of FIG. 3;
FIG. 7 is a waveform diagram illustrating in a continuous form the stirring voltage shown in FIG. 6;
FIG. 8 is a plan of an electrostatic ink jet recording apparatus, which is a second preferred embodiment of the invention, partly shown cross-sectionally;
FIG. 9 shows a cross section on the Y--Y line in FIG. 8;
FIG. 10A is a plan of an electrostatic ink jet recording apparatus, which is an alternative version of the second preferred embodiment of the invention, partly shown cross-sectionally;
FIG. 10B shows a profile of the electrostatic ink jet recording apparatus of FIG. 10A; and
FIG. 11 shows a cross section on the Z--Z line in FIG. 10A.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In FIGS. 1 and 2, the ink jet recording apparatus has an electrostatic ink jet recording head 10 and a counter electrode 20 arranged at a prescribed distance from the ink jet recording head 10. On the surface of the counter electrode 20 is arranged a recording medium P, which is carried by a carrying mechanism (not shown) in the direction of arrow S in FIG. 2. The counter electrode 20, consisting of an electroconductive body, is grounded so as to give its surface a potential of 0 (V).
The ink jet recording head 10 has a head body 1, an ejection electrode 2, an electrophoretic electrode 4, stirring electrodes 5A and 5B, an ink inlet 6 for feeding ink liquid, and an ink chamber 8 for storing the ink liquid. The ink liquid fed to the ink chamber 8 is a charge sensitive ink, which consists of charged particulate material (toner particulates) of thermoplastic resin, colored together with a charge control agent, dispersed in a petroleum-derived organic solvent (iosparaffin). The toner particulates are charged in an apparent positive polarity by a zeta potential. The ink inlet 6, connected to an ink tank (not shown) by a tube, feeds ink liquid into the ink chamber 8. In this process, a negative pressure of about 1 cm H 2 O is given to the ink liquid, which is thereby subjected to forced circulation.
The head body 1 consists of a dielectric substance, and the ink chamber 8 is formed within it. At the end of the ink chamber 8 in the ink ejecting direction is formed an ejection port, that is a minute ejection hole 3, from which part of the ink liquid is ejected. The ink chamber 8 is formed so that the cross-sectional area of its space gradually diminishes toward the ejection hole 3, underneath which is arranged the ejection electrode 2.
The ejection electrode 2 extends upward from the bottom face of the head body 1, and its tip electrode section 2A extends toward the ejection hole 3. The tip of the tip electrode section 2A is sharpened to facilitate concentration of the electric field. An insulating film 7 is formed above the tip electrode section 2A. The insulating film 7, is a protective film to prevent the ink liquid from coming into contact with the tip electrode section 2A.
The electrophoretic electrode 4 is formed by the rear face, reverse to the ink ejecting direction, and two side faces of the head body 1. The electrophoretic electrode 4 is fed with an electrophoretic voltage having the same polarity as the charge polarity of the toner particulates in the charge sensitive ink liquid. This electrophoretic voltage generates a phenomenon of electrophoresis in which the toner particulates in the ink liquid fed from the ink inlet 6 shift toward the counter electrode 20, i.e. the ejection hole 3. As the cross-sectional area of the space in the ink chamber 8 diminishes toward the ejection hole 3, the density of the toner particulates increases as they move toward the ejection hole 3.
The stirring electrodes 5A and 5B are formed respectively above and below the gravity direction of the ink chamber 8, and connected to a stirring voltage generating circuit 9. The stirring electrode 5A is formed over the ink chamber 8 reverse to its gravity direction. An insulating layer 70 covers the stirring electrode 5A so that the electrode 5A does not come into contact with the ink liquid. The Stirring electrode 5B, positioned under the ink chamber 8, is formed so as to come into contact with the ink liquid. The stirring voltage generating circuit 9, having a D.C. offset power source 9A for generating a stirring offset voltage and an A.C. power source 9B for supplying a stirring A.C. voltage, generates a voltage in which the stirring A.C. voltage is superposed over the stirring offset voltage, and feeds it between the stirring electrodes. The stirring offset voltage has the same polarity as the charge polarity of the toner particulates. The connection of the positive pole side of the stirring offset voltage to the stirring electrode 5B causes the electric field generated by the stirring offset voltage to be directed reverse to the gravity direction. This causes the positively polarized toner particulates having accumulated at the bottom of the ink chamber 2 to shift in the direction of the electric field. The stirring A.C. voltage supplied at the same time as the stirring offset voltage contributes to more efficient stirring of the toner particulates. Here, if the charge polarity of the toner particulates is reverse, this can be corrected by reversing the relationship between the positive and negative poles of the stirring offset power source 9A.
FIG. 3 illustrates the configuration of the circuit to drive the ejection electrode 2, electrophoretic electrode 4 and stirring electrodes 5A and 5B. Referring to the diagram, a control circuit 30 controls an electrophoretic voltage generating circuit 31, an ejection voltage generating circuit 32 and the stirring voltage generating circuit 9 on the basis of print data. The electrophoretic voltage generating circuit 31 generates the electrophoretic voltage to drive the electrophoretic electrode 4. The ejection voltage generating circuit 32 generates the ejection voltage to drive the ejection electorde 2. The stirring voltage generating circuit 9, as shown in FIG. 2, has the stirring offset power source 9A and the A.C. power source 9B. The electrophoretic voltage may be, for instance, 2 (kV), the ejection voltage, 1 (kV), and the stirring offset voltage from the D.C. offset power source 9A, 500 (V), and the amplitude of the stirring A.C. voltage from the A.C. power source 9B may be 1 (kV). These voltages are determined by the charge characteristic of toner particles, the distance between the ink jet recording head 10 and the counter electrode 20, and the structures of the various electrodes, but not confined to the above-stated values. The frequency of the stirring A.C. voltage from the A.C. voltage 9B, which determines the period of stirring, may be set to the experimentally optimal value.
The control circuit 30, after the start-up of the apparatus, controls the stirring voltage generating circuit 9 and the electrophoretic voltage generating circuit 31 so that the stirring voltage be fed to the stirring electrodes 5A and 5B before the electrophoretic voltage is applied to the electrophoretic electrode 4. It also controls the stirring voltage generating circuit 9 so that the stirring voltage be generated when no ejection voltage is fed to the ejection electrode in accordance with print data.
Next will be described the printing operation. When the electrophoretic voltage is fed to the electrophoretic electrode 4, an electric field is formed between the electrophoretic electrode 4 and the counter electrode 20, and electrophoresis causes toner particulates to shift toward and concentrate in the ejection hole 3. Then, when a voltage pulse is applied to the ejection electrode 2, an electric field is formed between the tip electrode section 2A of the ejection electrode 2 and the counter electrode 20, and the agglomerations of toner particulates having concentrated in the ejection hole 3 fly from there toward the counter electrode 20. The agglomerations of toner particulates which have flown adhere to the recording medium P. On the other hand, the toner particulates which have been reduced in the vicinity of the ejection hole 3 by the ejection are again shifted by electrophoresis attributable to the electrophoretic voltage toward the ejection hole 3 to be readied for consecutive ejection. Repetition of these actions causes a toner image to be formed on the recording medium P that is carried. The recording medium P on which the toner image has been formed is carried to a fixed (not shown) and thermally fixed.
Hereupon, as the toner particulates have a greater specific gravity than the ink solvent, if they are allowed to stand for a long period of time, the toner particulates T precipitate in the ink chamber 8 as illustrated in FIG. 4. During printing, as the electrophoretic electrode 4 electrophoreses the toner particulates T to bring them together in the vicinity of the ejection electrode 2, the concentration of the toner particulates T becomes uneven in the ink chamber 8. Furthermore, since the consumption of the toner particulates T is not necessarily constant but varies with the image to be printed, the concentration of the toner particulates in the vicinity of the ejection electrode 2 is inconstant. In such a case, the toner particulates are not supplied in a uniform volume to the vicinity of the ejection electrode 2, resulting in the disadvantage that the volume of ejected toner varies with the recorded image and the printed image becomes uneven.
In view of this problem, in this preferred embodiment of the invention, the stirring voltage generating circuit 9 feeds the stirring voltage to the stirring electrodes 5A and 5B before the electrophoretic voltage is applied to the electrophoretic electrode 4, as shown in FIG. 6. The stirring voltage, as shown in FIG. 7, consists of the stirring A.C. voltage, 1 (kV) on a peak-to-peak basis, superposed over the stirring offset voltage, 500 (V). This causes an alternating electric field in the gravity direction to be formed in the ink chamber 8, and the toner particulates T which have precipitated therein soar as illustrated in FIG. 5. To describe this stirring action in more detail, the toner particulates T are shifted in the direction reverse to the gravity direction by the stirring offset voltage fed from the D.C. offset power source 9A in FIGS. 2 and 3 to the stirring electrodes 5A and 5B. Simultaneously with the stirring offset voltage, the stirring A.C. voltage is applied, and the toner particulates T rapidly shift contrary to the gravity direction while the A.C. voltage is high and in the gravity direction while the A.C. voltage is low (while its polarity is reverse). This process efficiently stirs the toner particulates T having precipitated and accumulated in the ink chamber 8, and their concentration is generally uniformized, too. After the application of this stirring voltage, the electrophoretic voltage is fed to the electrophoretic electrode 4, and the resultant electrophoresis shifts the toner particulates T in the direction of ink ejection and, after that, the ejection voltage causes the agglomerations of ink particulates to fly from the ejection hole 3.
As shown in FIG. 6, when printing is to be done, although the stirring voltage, electrophoretic voltage and ejection voltage generate in that order, the electrophoretic voltage may be supplied to the electrophoretic electrode 4 while the ejection voltage is being supplied to the ejection electrode 2. Further, if the stirring voltage is generated earlier than the electrophoretic voltage, the generating period of the electrophoretic voltage and that of the stirring voltage may partly overlap each other.
As so far described, in this preferred embodiment of the invention, the stirring electrodes 5A and 5B are fed with the stirring voltage to generate an electric field which has the same polarity as the toner particulates and shifts them contrary to the gravity direction. As a result, the toner particulates are prevented from precipitating, and their concentration in the charge sensitive ink liquid in the ink chamber is generally uniformized. This enables a uniform quantity of toner particulates to be supplied to the tip electrode section 2A of the ejection electrode 2, resulting in high-quality prints with no irregularity of recording. As the stirring electrodes 5A and 5B are also fed with the stirring A.C. voltage in addition to the stirring offset voltage, the toner particulates can be vigorously and rapidly stirred by the action of the resultant alternating electric field.
Moreover, as the stirring electrodes 5A and 5B function when no pulse voltage is applied to the ejection electrode, they not only have no adverse effect on the ejecting action but also consecutively perform stirring during the printing process. This serves to stabilize the quantity of toner particulates in the agglomerations irrespective of the image to be recorded, and enables high-quality prints to be obtained.
Furthermore, since the stirring voltage is generated before the application of the electrophoretic voltage to the electrophoretic electrode 4, the toner particulates are dispersed by the stirring, and the dispersed toner particulates can be quickly carried by electrophoresis to the ejection hole 3. It is thereby made possible to carry the right amount of toner particulates to the ejection hole 3 more smoothly than when they have precipitated, restrain unevenness of ejection, realize high print quality, and accomplish steady high-speed printing by the continuous ejection of toner particulates.
In the electrostatic ink jet recording apparatus illustrated in FIGS. 8 and 9, which is a second preferred embodiment of the present invention, an ink jet recording head 100 dispenses with the electrophoretic electrode 4 of the ink jet recording head 10 of FIGS. 1 and 2, and a stirring electrode 15B extends to a position opposite to the ejection hole 3. A stirring electrode 15A, arranged in a position opposite to the stirring electrode 15B with respect to the gravity direction, is formed from the ink inlet 6 to the vicinity of the ejection hole 3. A stirring electrode generating circuit 19 has a stirring offset power source 19A, and a stirring A.C. power source is dispensed with. In other respects, this embodiment has the same configuration as the above-described first embodiment.
As a stirring offset voltage, 1 (kV), is fed to the stirring electrodes 15A and 15B, the toner particulates which have precipitated therein soar, to become dispersed in the ink and uniformized. Since the stirring electrode 15B is formed not only on the bottom side of the ink chamber 8 but also on the face opposite to the ejection hole 3, the toner particulates in the vicinity of the ink inlet 6 shift toward the ejection hole 3 and the stirring electrode 15A. Accordingly, the stirring electrode 15B performs both the role of the stirring electrode 5B in FIG. 1 and that of the electrophoretic electrode to shift the toner particulates in the direction of ink ejection.
Thus, the ink jet recording head 100 can not only realize dispersion and uniformization of toner particulates and high-speed printing as does the ink jet recording head 10 of the first embodiment, but also can be reduced in cost commensurately with the absence of the electrophoretic voltage generating circuit and the A.C. power source for stirring.
The present invention is not limited to the preferred embodiments described above. For instance, the shapes of the ink chamber 8 and the ejection hole 3 are not confined to those used in the first and second embodiments. As illustrated in FIGS. 10A and 10B, an ink jet recording head 200 may have a plurality of ejection holes 23 arranged at regular intervals with partitions 24 in-between. In an ink chamber 80, unlike the ink chamber 8 in FIG. 1, the cross-sectional area of the space within does not converge toward the ejection holes. As shown in FIG. 11, the face of the ink chamber 80 opposite to the ejection holes 23 is formed in a flat or curved shape, slanted with respect to the gravity direction. This makes it difficult for toner particulates in the charge sensitive ink liquid to accumulate in the vicinity of the ink inlet.
On the bottom of the ink chamber 80 is formed an insulating film 40, underneath which is formed a stirring electrode 25B. The stirring electrode 25B and the insulating film 40 are formed from the ink inlet 6 to the vicinity of the ejection electrode 2. As the insulating film 40 simultaneously insulates the ejection electrode 2 and the stirring electrode 25B from the ink liquid, there is the advantage of simplifying the manufacturing process. When the stirring offset voltage is fed to the stirring electrodes 25A and 25B, toner particulates having precipitated and accumulated on the bottom of the ink chamber 80 soar, and are dispersed in the ink and uniformized. As the stirring electrode 25B is formed not only on the bottom side of the ink chamber 80 but also on its face opposite to the ejection holes 23, the toner particulates in the vicinity of the ink inlet 6 shift toward the plurality of ejection holes 23 and the stirring electrode 25A. Therefore, the stirring electrode 25 plays both the role of the stirring electrode 5B and that of the electrophoretic electrode in FIG. 1. | An electrostatic ink jet according to the present invention includes a head body having an ink chamber for holding ink liquid containing charged particulate material; an ejection port provided at one end of that head body and connecting to the ink chamber; an ejection electrode arranged near this ejection port and fed with an ejection voltage of the same polarity as the charge characteristic of the charged particulate material; a counter electrode arranged opposite to the ejection port via a recording medium; and a pair of stirring electrodes. The stirring electrodes are arranged in the direction reverse to that of gravity in the ink chamber. The stirring electrodes are fed with a stirring voltage for shifting the charge particulate material in the direction reverse to the direction of gravity, and that stirring voltage is generated before the generation of the ejection voltage. As a result, the toner particulates are prevented from precipitating before the ejection of ink, and their concentration in the ink liquid in the ink chamber is generally uniformized. | 1 |
BACKGROUND OF THE INVENTION
[0001] 1. Technical Field
[0002] The invention is in the field of bed covering for two or more users that permits a user to adjust coverage and, if two or more layers are used, thickness of his or her bed covering without discomforting another user of the bed covering.
[0003] 2. Related Art
[0004] When one person sleeping in a bed under common bed covering with a second person rolls away from the second person, the first person often pulls the bed covering off the second person, thereby uncovering and discomforting the second person. When two persons sleep on their sides in a bed under common bed covering, there is often a gap between the persons that allows drafts to enter the space between the persons, thereby discomforting both persons, especially in cold ambient air. Moreover, one person can not partially or completely remove one or more layers of that person's portion of common bed covering without discomforting the second. The general technical problems to be solved are to prevent the pulling off of bed covering in the first case, prevent the entry of drafts in the second case, and to give each person independent control of the coverage and thickness of bed covering in the third case.
[0005] The existing art of split-top bed covering involves two or more separate panels attached together to form a whole covering. For instance, U.S. Pat. No. 6,311,347, to Limardi, has left and right upper panels of a split bed covering sewn to a foot panel using a transverse seam. The inner longitudinal, or medial, edges of the upper panels overlap each other. The present invention avoid the need for a transverse seam and separate upper left, upper right, and foot panels.
[0006] U.S. Pat. No. 6,698,043, to Fabian, has left and right panels of a split bed covering sewn directly to each other at the bottom of the panels to form a short, central, longitudinal seam. The description in Fabian requires the upper end of the longitudinal seam (joined portion) of the panels to be positioned in a bed at the top edge of the foot of the mattress so that a user can completely remove a left or right, first or second, upper panel. Fabian has no “foot panel”, per se. The left and right upper panels of Fabian's invention must be sewn together, and the top covering comprises two sheets in each left and right panel of the bed covering. The present invention avoids the need for a longitudinal seam, separate left and right panels, and two sheets in each left and right panel of the bed covering. Fabian's invention also lacks a means of fastening the left and right panels in the upper portion of the bed covering.
[0007] Similarly, U.S. Pat. No. 7,200,883 to Haggerty, U.S. Pat. No. 6,862,760 to Bradley, and U.S. Pat. No. 6,643,871 to Robke use multi-panel, sewn, construction, rather than an integral, non-woven textile.
[0008] Unlike the bed coverings disclosed in the patents cited above, the instant invention can be manufactured as a single sheet, without any sewn seams, thereby reducing the structural elements that comprise the article of manufacture and greatly reducing the cost of manufacture. Moreover, the instant invention can be manufactured for use by three concurrent users, e.g., parents and a child disposed between them.
[0009] Split-top bed covering has not been widely adopted, in part because of the additional cost of production of split-top bed covering compared with traditional, integrally manufactured bed covering makes split-top bed covering significantly more expensive. The general technical problem to be solved is to provide a split-top bed covering that is less expensive to manufacture, specifically one that takes advantage of non-woven textile technology and does not require sewing together of separate, prefabricated panels. The present invention solves both the general and the specific technical problems.
SUMMARY OF THE INVENTION
[0010] The split-top, integral bed covering invention comprises left and right upper portions and a foot portion made from a single, integral piece of textile. In embodiments for two users, the left and right upper portions each have inner, medial wings that are free of the foot portion. In normal use, the inner, medial wings of the left and right upper portions overlap each other. The overlap of the medial wings of the left and right upper portions, and freedom of the medial wings from the foot portion, is achieved in the original manufacturing of the textile, as opposed to fastening separate left and right elements to each other or to a foot panel by sewing, bonding, or other fastening means. The edges of the bed covering can be hemmed, or for simplicity, unhemmed. Optional embodiments include a means for reversibly fastening left and right medial wings, which facilitates spreading the bed covering on a bed, hanging the bed covering for air drying, and providing traditional bed covering functionality. Additional elements, such as hems and ornamentation, can be added to the textile. The left, right, and foot portions can optionally have the same or different textural, insulative, ornamental, decorative, or other treatments. Embodiments of the invention can be manufactured with more than two top portions. Multiple layers of the split-top, integral bed covering can optionally be joined at the foot during manufacturing, e.g., by heat bonding. The split-top, integral bed covering can optionally be manufactured in fitted foot versions.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 shows a plan view of a split-top, integral bed covering, with left medial wing open and right medial wing closed.
[0012] FIG. 2 shows a plan view of a split-top, integral bed covering, with medial wings open.
[0013] FIG. 3 shows a plan view of a split-top, integral bed covering, covering two users, with medial wings closed.
[0014] FIG. 4 shows a cross section of FIG. 2 in the area of the medial wings, depicting how the medial wings conform to the users' bodies.
[0015] FIG. 5 shows a plan view of a split-top, integral bed covering, with left medial wing open and right medial wing closed, showing with hook and loop fasteners.
[0016] FIG. 6 shows a cross section of a split-top, integral bed covering, with medial wings open and with hook and loop fasteners in the area of the medial wings.
[0017] FIG. 7 shows a plan view of a split-top, integral bed covering, with left medial wing open and right medial wing closed, showing with hook and loop fasteners with protective flaps.
[0018] FIG. 8 shows a cross section of hook and loop fasteners of FIG. 6 , with protective flap opened to allow the fasteners to engage, in the area of the medial wings.
[0019] FIG. 9 shows a plan view of a three person, split-top, integral bed covering, with medial wings open.
[0020] FIG. 10 shows a plan view of a three person, split-top, integral bed covering, with medial wings closed.
[0021] FIG. 11 shows a cross section of FIG. 10 in the area of the medial wings, depicting how the medial wings conform to the users' bodies.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0022] “Longitudinal” means along the head to foot axis with respect to a split-top bed covering as it covers a person lying in a bed. “Mattress” means herein any top substrate provided in a bed and on which a person lies. “Latitudinal” means the axis perpendicular to the longitudinal axis of the split-top bed covering. “Left” and “right” are referenced as if the viewer were overhead a split-top bed covering as it covers a bed. The “top edge” of a split-top bed covering is the latitudinal edge of the bed covering placed along the head of the bed on which a split-top bed covering is placed. The “foot edge” of a split-top bed covering is the edge opposite the top edge and is typically tucked under the mattress on which the split-top bed covering is placed. The top edge and the foot edge are typically parallel. “Sheet” means herein any bed-covering textile, e.g., comforter, blanket, duvet, sheet, quilt, etc. “Wing” means herein the medial part of an upper portion of a split-top, integral bed covering is that is free of (i.e., is not attached to and moves independently of) the foot portion. “Transverse line” means herein the latitudinal line formed by the top, medial part of the foot portion of a split-top bed covering, which portion is not integral with a wing or an upper portion, wherein such latitudinal line is extended transversely to the left and right edges of the split-top bed covering. The left edge and the right edge of the split-top bed covering are typically parallel. “Wing hinge” means herein the longitudinal line formed by extending longitudinally, to the top edge of the split-top bed covering, the most medial point at which an upper portion is integral with the foot portion of a split-top bed covering. The transverse line and wing hinge are for descriptive purposes only and are not actually creased or otherwise formed in the split-top bed covering during manufacturing.
[0023] The split-top, integral bed covering invention comprises left and right upper portions and a foot portion made from a single, integral sheet of textile. In embodiments for two users, the left and right upper portions each have inner, medial wings that are free of the foot portion. In normal use, the inner, medial wings of the left and right upper portions overlap each other. The overlap of the medial wings of the left and right upper portions, and freedom of the medial wings from the foot portion, is achieved in the original manufacturing of the textile, as opposed to fastening separate left and right elements to each other or to a foot panel by sewing, bonding, or other fastening means.
[0024] The invention (1) allows one user to roll in bed without pulling off the bed covering of a second person (the medial wing of the rolling person is pulled along with the rolling motion, but not the medial wing or upper bed covering portion of the second person), (2) prevents entry of drafts between two persons sleeping on their sides (the medial wings contour around the first and second persons, rather than forming a canopy above the mattress like traditional bed covering), and (3) gives each person independent control of the thickness of bedding covering (a first user can remove one or more layers of split-top, integral bed covering without disturbing the layers on a second person in bed).
[0025] The split-top, integral bed covering can be produced as a non-woven textile. Non-woven textiles (“non-wovens”) are textiles that are manufactured by putting small fibers together in planar form and then binding the fibers together mechanically (e.g., interlocking the fibers using serrated needles, by hydroentanglement by water jets, etc.), with an adhesive (e.g., latex polymers), or thermally (calendering through heated rollers). A mesh backing or core is normally introduced in the laying of the fiber for bed coverings to produce stronger non-woven textiles. Non-woven textiles used in the invention can be carded, weblaid, or spunlaid. Non-wovens are typically produced from synthetic fibers; spunlaid non-woven manufacturing can combine a stage that produces synthetic fiber with immediate laying of the fiber in planar form, which greatly reduces manufacturing costs.
[0026] The fibers used to made the split-top, integral bed covering include cashmere, chenille, flannel, cotton, silk, fleece, mink, wool, and synthetic fibers. Synthetic fibers used to make the split-top, integral bed covering include polypropylene and polyesters, particularly polyethylene terephthalate.
[0027] The split-top, integral bed covering can also be produced using specially fitted weaving looms and knitting looms, by crocheting, by knotting, tufting, by composite (i.e., more than one textile manufacturing method), and by other known methods of textile production. Most woven textiles are made on looms and consequently are rectilinear when weaving is finished. The split-top, integral bed covering invention, with its “hinged” medial wings, is particularly suited for production as a non-woven textile made of synthetic fiber, since non-woven textiles can be easily laid and finished in odd shapes.
[0028] The invention solves the technical problem of reducing the cost of manufacturing split-top bed covering by providing a design that is especially suited to non-woven textile technology, has fewer structural elements, and does not require sewing together of separate, prefabricated panels.
[0029] As shown in FIG. 1 , the width of overlap (“Wing Width”) of a wing is defined by the distance ( 11 ) from a wing hinge ( 12 ) to the medial edge ( 13 ) of the wing. Normally, the width of a left wing ( 14 ) is the same as the width of a right wing ( 11 ). The “Overall Length”( 15 ) is the distance from the top edge to foot edge of the bed covering deployed planarly.
[0030] As shown in FIG. 2 , the length of a foot portion ( 21 ) (“Foot Portion Length”) is defined by the distance ( 22 ) from the transverse line ( 23 ) to the foot edge ( 24 ) of a split-top bed covering. The “Overall Width” ( 25 ) is the distance from the left edge to right edge of the bed covering deployed planarly.
[0031] The split-top, integral bed covering is normally manufactured in an embodiment for two users, and therefore is most commonly made in queen, king, and California king sizes. The Wing Width ranges from 20% to 60% of the Overall Width, more preferably from 25% to 40% of the Overall Width, and most preferably from 30% to 35% of the Overall Width. The Foot Portion Length ranges from 20% to 50% of the Overall Length, more preferably from 20% to 40% of the Overall Length, and most preferably from 25% to 30% of the Overall Length for normal mattresses and from 30% to 35% for pillow-top mattresses.
[0032] The transverse line does not need to be precisely positioned during use. If the user wants the foot portion to cover the feet of the user, less of the foot portion is tucked under the mattress so that the transverse line is placed more headward, past the top of the foot of the mattress, e.g., the transverse line may be placed in the area of the user's calves or knees. If the user wants to be able to completely remove the upper portion as a bed covering on his or her portion of the bed, the transverse line is placed no higher than the top of the foot of the mattress. The split-top, integral bed covering can be made in various configurations that have different combinations of Wing Widths, Overall Widths, Overall Lengths, and Foot Portion Lengths to accommodate user preferences and mattress sizes.
[0033] As shown in FIGS. 3 and 4 , the wings conform to the contours of users' bodies.
[0034] As shown in FIGS. 5 and 6 , alternative embodiments include the hook and loop fasteners ( 61 , 62 ), or other means, to reversibly fasten the left and right medial wings to each other. As shown in FIG. 6 , reversible fasteners (when fastened) improve the ability to position the bed covering on a bed, hang the bed covering for air drying, and provide traditional bed covering functionality. Other fastening means include buttons and corresponding button holes, snaps, knotted rope and loops, and magnetic strips embedded in the medial edges and near the wing hinge.
[0035] As shown in FIGS. 7 and 8 , the hook and loop fasteners are covered with displaceable flaps ( 71 , 81 ). The interior of the flaps has fastening matching the fastener on the wing, e.g., a hook fastener on a wing mates with a loop fastener on the flap. Using flaps prevents unintentional engagement of the fasteners, e.g., while the users are sleeping. If a user wishes to join the wings together, a flap is displaced to expose the relevant fastener, and the exposed fasteners on the wings are mated.
[0036] Although FIGS. 5 to 8 show two columns of fasteners on each wing, only one column of fasteners can be used. Using one column does not immobilize the medial edges of both wings, however, and is not preferred.
[0037] Additional elements, such as hems and ornamentation, can be added to the split-top, integral bed covering. The left, right, and foot portions can optionally have different textural, insulative, decorative, or other treatments, e.g., sports logos, pictures, “his and her” colors or decoration, etc.
[0038] Multiple split-top, integral bed coverings can be used simultaneously, e.g., top sheet, first blanket, and quilt. A user may remove one or more layers of bed covering without disturbing the bed covering of the other user.
[0039] The split-top bed covering can be made with a fitted foot portion, i.e., the split-top, integral bed is made with a pocket in the foot portion that accommodates the depth and width of a mattress. In fitted foot portion embodiments, the position of the transverse line is fixed. Not only bedsheets, but blankets, quilts, and other bedcovering can be made in fitted embodiments.
[0040] Although the medial wings described above and shown in the Figures have the left medial wing overlapping the right medial wing, the invention can also be constructed with the right medial wing overlapping the left medial wing. This distinction is of importance only when fasteners are incorporated in the design; the manner of overlap determines which medial wing has fasteners on the bottom surface of a given wing, which requires the opposite wing to have fasteners on the top surface of such opposite wing.
[0041] The split-top, integral bed covering can be manufactured with more than two upper portions. As shown in FIG. 9 , a three person, split-top, integral bed covering, has three upper portions. The upper left portion has a medial wing ( 91 ), the upper right portion has a medial wing ( 92 ); the wings overlap an upper center portion ( 93 ).
[0042] As shown in FIGS. 10 and 11 , the wings of an embodiment of the invention for three users conform to the bodies of the three users.
[0043] Embodiments of the split-top, integral bed covering can be made in which the longitudinal and latitudinal axes are reversed so that the top edge runs along the long side of a mattress (i.e., the head and foot of the bed mattress are rotated 90 degrees). This “landscape” mode (versus “portrait” mode) of use is especially suited for split-top, integral bed coverings with three or more upper portions. The principal use of such embodiments is when more than two children share a large bed. Given the split-top nature of the bed covering, barriers (e.g., tubular pillows) can be placed in the splits to separate the sleeping spaces of the children. The barriers can be integral with the bed-covering, or independent.
[0044] The split-top, integral bed covering of the invention enables each of the users to determine his or her comfort level without affecting the other users. For example, each of the users can begin sleeping with their covering moved aside. Then as the night progresses, and more warmth is needed, each user can easily reach down and independently retrieve his or her bed covering. This can be done without disturbing another user in the bed.
[0045] Multiple layers of the split-top, integral bed covering can optionally be joined at the foot during manufacturing, e.g., by heat bonding. In a multi-layer embodiment of a fitted foot version, only the bottommost layer needs to have a fitted foot.
[0046] Variations, modifications, equivalents and substitutions for components of the specifically described embodiments of the invention may be made by those skilled in the art without departing from the spirit and scope of the invention as set forth in the appended claims. | A split-top, bed covering for two users comprising a single, integral sheet of textile with a left upper portion with medial wing, a right upper portion with medial wing, and a foot portion is described. All portions, including wings, are formed seamlessly during manufacturing of the textile. The medial wings of upper left and right portions overlap. The textile may be, inter alia, of woven, non-woven, crocheted, knitted, knotted, tufted, or composite construction. | 0 |
RELATED APPLICATION
This application claims priority to U.S. Provisional Application No. 61/314,752, which was filed on Mar. 17, 2010.
BACKGROUND OF THE INVENTION
Flush valves may have a handle that, when manipulated, pushes an actuator which, in turn, opens a bypass valve within a piston in the flush valve. By opening the bypass valve, pressure above the piston drops and allows line pressure to lift the piston from its seat within the flush valve and channel water to flush a toilet, urinal or the like. While the toilet or urinal fixture is being flushed, line pressure is also directed above the piston increasing the pressure in this area. As the pressure equalizes the piston seats itself within the flush valve and stops flow therethrough.
Commercial flush valves sometimes experience problems such as water hammer and failure to shut off. Water hammer may occur if water in motion is forced to stop or change direction suddenly. This rapid change in momentum creates a surge in pressure and results in shock waves that propagate through the piping making noise. Some plumbing codes require flush valves to have anti-backflow devices like a vacuum breaker to prevent fouling of the potable water supply in the event of backflow from the toilet or urinal fixture into the valve and the related water supply.
SUMMARY OF THE INVENTION
A flush valve has a valve body having an inlet and an outlet, and a piston disposed in the valve body between the inlet and the outlet. A surface is disposed in the valve body for seating the piston. The surface tapers inwardly as it passes into the outlet wherein the taper improves the flow characteristics of fluid passing by the taper thereby minimizing water hammer and leakage therethrough.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective cutaway view of the flush valve of the invention.
FIG. 2 is a perspective view of the valve of FIG. 1 .
FIG. 3 is a side view of the piston body of FIG. 2 .
FIG. 4 is a perspective view of the piston cap of FIG. 2 .
FIG. 4 a is a top view of the piston cap of FIG. 4 .
FIG. 5 is a perspective view of the anti-backflow prevention device of FIG. 1 .
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1 , the flush valve 10 of the invention is shown. The flush valve 10 has a valve assembly 15 , an actuator assembly 20 (as in known in the art), an anti-back flow cartridge 30 and a discharge tube 35 that disgorges water into a toilet or urinal (not shown) or the like.
Referring now to FIGS. 2 and 3 , the valve assembly 15 has an inlet 40 disposed in a valve body 45 , a piston 50 operating in the valve body 45 , a piston cap 55 and an outlet 60 disposed in the valve body. The piston 50 comprises a piston guide 65 , a piston body 70 , an o-ring 75 , a bypass seal 80 , an actuator 85 , a collar 90 , a bypass valve 95 , a spring 100 , a cap 105 , and a wiper seal 110 .
The piston guide 65 has a tapered interior 115 , a circular cutout 120 for holding the o-ring 75 , a shoulder 125 for mounting the bypass seal 80 and threads 130 for mating with the threaded piston body interior 135 . An extended portion 142 of the piston guide 65 extends beyond a tapered portion 140 of the valve body 45 if the piston 50 is seated. The piston body 70 extends along central longitudinal axis A of the valve assembly 15 . The tapered portion 140 of the valve body 45 tapers inward along an axial length L 1 of the axis A, and the tapered interior 115 tapers radially outwardly along an axial length L 2 of the axis A. As shown in FIG. 2 , L 2 is greater than L 1 . Also, when the valve assembly 15 is in the closed position (as shown in FIG. 2 ), the axial lengths L 1 and L 2 overlap, and the entirety of length L 1 overlaps with length L 2 .
The piston body 70 has a lower cutout 145 for holding the o-ring 75 and an interior ledge 150 for holding the bypass seal 80 . The shoulder 125 of the piston guide 65 and the interior ledge 150 of the piston body 70 position the bypass seal therebetween 80 . Similarly, the circular cutout 120 of the piston guide 65 and the lower cutout 145 of the piston body trap the o-ring 75 therebetween.
The o-ring 75 seats the piston 50 on the tapered portion 140 of the valve body 45 . In this embodiment, the tapered portion of the seal has a length of 0.125 inches and is disposed at an angle of 20° relative to the outlet, though other angles and lengths are possible for other valves.
The bypass valve 95 , which seats on the bypass seal 80 , has a threaded interior 155 for receiving the threaded portion 160 of the actuator 85 . The actuator is attached to the collar 90 that interacts with the actuator assembly 20 (see also FIG. 1 ) to move/tilt the bypass valve 95 off of the bypass seal 80 as will be discussed herein.
The cap 105 , which is circular, has a central opening 165 therein, and a set of downwardly extending threads 170 that attach to the interior threads 175 in the piston body 70 . The cap 105 seats the spring 100 between it and the bypass valve 95 . The cap also fixes the wiper seal 110 between it and an outer ledge 180 in the piston body.
The piston 50 moves upwardly and downwardly within the valve body 45 and within the piston cap 55 , which is conventionally fixed for easy access within the valve body 45 . An area 185 for holding fluid is defined in the piston cap 55 above the piston 50 . The wiper seal 110 extends beyond the edges of the valve to form an interference fit with an interior wall 190 of the guide (see also FIG. 4 ) as will be discussed herein.
Referring to FIG. 3 , the piston body 70 is shown. The piston body has a neck 200 , a body portion 205 having a larger perimeter than the neck, and a shoulder 210 having a rounded portion 220 and a larger perimeter than the neck. The body portion has a taper 225 therein that slopes inwardly towards the neck 200 . In the embodiment shown herein, the taper is disposed at an angle of approximately 20° relative to the shoulder and has a length of approximately 0.168 inches. The rounded portion 220 of the shoulder 210 has a radius of approximately 0.04 inches. Other combinations and permutations of radius, angle and length may be used in other valves if they provide the benefits of this invention.
Referring to FIGS. 4 and 4 a , the piston cap 55 is shown having, in the embodiment shown, a groove 230 having a depth of approximately 0.006 inches and a Ø of about 0.040 inches disposed in the inner wall 190 . The groove extends from a bottom 235 of the valve guide 55 to a top 240 thereof to communicate fluid from the valve inlet 40 to the area above the valve 185 . The shape of the groove 230 minimizes a possibility that debris (not shown) might get stuck in or clog the groove. The groove is further sized to allow fluid to equalize above the piston 50 to seat the piston as will be discussed herein while allowing enough fluid to pass by the wiper seal 110 to achieve an adequate flushing function. If the groove is too small in area, the valve will be open too long and if too large in area, too short.
Before the valve 15 is operated, pressure is equalized between the area 185 within the piston cap 55 above the piston 50 and line pressure in the plumbing system (not shown) within the inlet 40 . Pressure in the outlet 60 is low as fluid has been disgorged therethrough. During operation of the piston 50 , if the actuator assembly 20 is manipulated, the collar 90 is tilted and the actuator 85 attached thereto tips the bypass valve 95 off the bypass seal 80 against the force of the spring 100 to allow fluid to flow from the area 185 above the piston thereby lowering the pressure therein. Line pressure in the inlet 40 therefore pushes the valve 50 off its seat 140 within the valve body 45 to allow fluid to flow past the neck 200 of the piston body 70 , the o-ring 75 , the extended portion 142 of the piston guide 65 , the rounded portion 220 of the piston body shoulder 210 , and the piston body taper 225 that slopes inwardly towards the neck 200 , to exit the valve.
As the valve 50 operates, inlet fluid flows through the groove 230 , bypassing the wiper seal 110 , gradually allowing pressure in the area 185 above the piston 50 to equalize with the line pressure thereby gradually moving the piston 50 down along the inner wall 190 of the piston cap 55 until o-ring 75 seals against the tapered portion 140 of the valve body 45 . As the valve moves, the wiper seal 110 tends to remove debris that might clog or block fluid from flowing in the groove in the piston cap 55 .
The extended portion 142 of the piston guide 65 , in conjunction with the o-ring 75 and the tapered portion 140 of the valve body 45 , helps to create a funnel to minimize turbulent flow from the valve 50 as the valve seats on the tapered portion 140 of the housing 45 thereby minimizing water hammer. Similarly, the tapered portion 225 and the rounded portion 220 of the piston body 70 , collectively and individually, smooth flow around the piston body also minimizing the effects of water hammer in the valve. Additionally, the neck portion 200 of the piston body 70 allows inlet pressure to be more equally distributed therearound thereby centering the valve more efficiently thereby easing translation of the valve in the piston cap 55 and extending valve life.
Referring now to FIGS. 1, 5, and 5 a , the anti-backflow cartridge 30 is shown. The cartridge has a tubular housing 250 that slips into the discharge tube 35 . The tubular housing has a lip 255 that prevents the housing from slipping down into the discharge tube thereby giving a user easy access to the cartridge if maintenance is required. A pair of anti-backflow check valves 260 , manufactured by Neoperl, are arranged in series in the tubular housing and each are held therein the tubular housing 250 . The anti-backflow valves provide enough resistance to minimize backflow while allowing enough flow to maximize the use of the toilet or urinal. The o-rings 265 also prevent fluid from flowing around each anti-backflow check valve back to the valve assembly 10 . A flange 280 may extend inwardly at a bottom of said tubular housing 250 .
In an alternative embodiment shown in FIG. 1 , the cartridge 250 is the discharge tube and if the cartridge needs replacement, the discharge tube is replaced therewith. The discharge tube 35 has a set of threads 255 therearound for mating with the threads 285 of the valve body 45 .
Each anti-backflow valve 260 prevents fluid from flowing up from the toilet or urinal (not shown) so that neither the water supply nor the valve assembly 15 is contaminated by the fluid. The anti-backflow valves replace vacuum breakers (not shown) and also have a much longer life than a typical prior art vacuum breaker.
The foregoing description is exemplary rather than defined by the limitations within. Various non-limiting embodiments are disclosed herein, however, one of ordinary skill in the art would recognize that various modifications and variations in light of the above teachings will fall within the scope of the appended claims. For instance, one of ordinary skill in the art will recognize that other designs such as objects, abstracts, architectural features may be substituted for the designs shown herein. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced other than as specifically described. For that reason the appended claims should be studied to determine true scope and content. | A flush valve has a valve body having an inlet and an outlet, and a piston disposed in the valve body between the inlet and the outlet. A surface is disposed in the valve body for seating the piston. The surface tapers inwardly as it passes into the outlet wherein the taper improves the flow characteristics of fluid passing by the taper thereby minimizing water hammer and leakage therethrough. | 4 |
This application is a continuation of application Ser. No. 909,684, filed on Sept. 22, 1986, now abandoned, which in turn is a division of application ser. No. 833,033, filed Feb. 26, 1986, now abandoned.
BACKGROUND OF THE INVENTION
The present invention concerns monolithic substrates for electronic power components. Such substrates are formed by a sintered stack of layers of dielectric material, generally a ceramic, or an alumina for hyperfrequency applications.
Such substrates can be used both for carrying semiconductor devices at a high density (they are then known as a chip carrier), or as substrates which are intended for producing hybrid circuits, using a procedure which is conventional in itself. In both cases, the substrates are often interconnection substrates, that is to say they include integrated conducting connections (which are buried in the substrate or formed at the surface thereof) which will subsequently be connected to terminals of the component. Such interconnections are often distributed over a plurality of layers, wherein interconnections from one layer to another and to the surface of the substrate are incorporated in accordance with a predetermined layout.
By virtue of the high density of the components, or when there is a wish to use power components (amplifiers in a hybrid circuit for example), it becomes necessary to absorb and dissipate a substantial amount of heat which is given off by the components. By way of example, it is often necessary to dissipate an amount of power of the order of 35 watts by means of a substrate of standardized dimensions of 152.4×86.36 mm.
For that purpose, the material generally chosen for the substrate is a material which is a good conductor of heat such as alumina which also has excellent dielectric and mechanical properties. That choice is important in particular when very strong currents pass through the buried interconnections, in order to drain the heat produced in the center of the substrate towards the surface thereof.
In order to dissipate the heat which is drained away in this manner, a first method contemplates using metallic radiators which are glued to the back of the substrate, the heat being discharged by conduction through the mass of the radiator and then by natural or forced convection to the ambient atmosphere.
Another procedure which can be used in combination with that described above comprises providing, in the center of the substrate, metallization portions which act as heat sinks and which open onto a face of the substrate by way of studs which are then welded to a metal chassis made, for example, of copper or Duralimin.
However those two methods suffer from the disadvantages that they occupy a complete face of the substrate which is therefore no longer available for carrying components, they necessitate substantial metal masses in order to remove the heat produced by conduction and convection, and finally, for that reason, they limit the options in regard to physical arrangements of the substrate and the components within the piece of equipment.
At any event, the possibility of in situ absorption of the heat produced is limited by virtue of the interposition of an intermediate member, a heat sink or a radiator.
SUMMARY OF THE INVENTION
The present invention proposes a novel substrate sructure which permits those disadvantages to be overcome.
For that purpose, the substrate of the present invention includes an internal system of ducts for the circulation of a cooling fluid. The duct sysem is a closed system which opens at the surface of the substrate by way of two orifices, one of which provides for the intake of the pressurized fluid into the internal duct system and the other for the removal thereof from said system.
Preferably, the system is formed by duct segments each limited to selected layers. The entire system of duct segments are distributed over a plurality of levels with respect to the thickness of the stack, each of which consists of one or more layers and has a duct segments extending therethrough. The segments are interconnected from one level to the next.
Preferably, the interconnection between the duct segments is formed by wells formed by the removal of material in the layers through which the fluid is to pass.
Alternatively, or in addition, the interconnection between the duct segments may also be produced by mutually facing regions of the duct segments which belong to two adjacent layers.
In a first embodiment, the duct segments are defined between two adjacent layers by a residual volume which is formed at the interface of said layers along a predetermined pattern.
In a second embodiment, the ducts are defined by the removal of material in certain layers of the stack, in accordance with a predetermined pattern.
The invention also concerns a process for the production of the substrate in accordance with the first embodiment referred to above, wherein the residual volume is produced by the deposit of an evanescent ink in accordance with the predetermined pattern on at least one of the sheets of raw dielectric material before stacking, said ink being an ink which has no mineral pigment and which is suitable for preventing cosintering of the two adjacent layers along said pattern during baking.
BRIEF DESCRIPTION OF THE DRAWINGS
Various other objects, features and attendant advantages of the present invention will be more fully appreciated as the same becomes better understood from the following detailed description when considered in connection with the accompanying drawings in which like reference characters designate like or corresponding parts throughout the several views and wherein:
FIG. 1 is a sectional view of a substrate in accordance with the first embodiment of the invention;
FIG. 2 is the same view as that shown in FIG. 1, but of a second embodiment of the invention; and
FIGS. 3a to 3d are plan views showing the layout of the openings which are punched into each of the layers of the substrate in FIG. 2 to form the fluid flow system of the embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
It will first be noted that, in the following description, the system of ducts for the circulation of the cooling fluid is integrated in the substrate, the electrical interconnection levels and the duct interconnection levels being in interleaved relationship. The invention however also applies to substrates in which the system of electrical interconnections and the system of ducts are two staged, noninterleaved systems: that is the case in particular when the final substrate is produced from two superposed substrates which are joined together to form a single monolithic element (by sintering, gluing etc.), one of the initial substrates being a conventional electrical interconnection substrate and the other initial substrate being a specific cooling substrate which is joined to the former.
On the other hand, the preferred material used for the substrates is alumina, by virtue of its excellent thermal properties (a very good conductor), dielectric properties (permitting use in relation to hyperfrequencies), and mechanical properties. A preferred composition is that which is described in detail in French patent application No 83-19689, filed Dec. 8, 1983 and entitled "Alumina Interconnection Substrate for an Electronic component": that composition comprises from 92% to 98% of Al 2 O 3 (preferably 96%), the balance comprising magnesium titanate whose formula is between (TiO 2 , 0.5 MgO) and (TiO 2 , 6 MgO), preferably (TiO 2 , MgO), the conductor tracks being made of palladium or a silver-palladium alloy.
That composition has the advantage of retaining all the properties of ultra-pure alumina while reducing the maximum baking temperature to a value of the order of 1400°, which baking operation may be carried out in an oxidizing atmosphere.
If that composition is a preferred composition, it is nonetheless not limitative and other materials may be used such as ultra-pure alumina or ceramics of conventional types which are used for this type of substrate.
FIG. 1 shows a first embodiment in which the substrate 10 is formed by a sintered stack of layers 11, 12, . . . 18 of dielectric material. The internal system of ducts is formed by a series of duct segments 21, 22, 23 defined between two adjacent layers (for example the layers 12 and 13 or 15 and 16 respectively) by a residual volume formed at the interface of the layers, along a prefetermined pattern. The interconnections are formed by means of wells 24 and 25 formed by removing material from the layers through which the fluid is to pass. The drawing shows the orifice for the intake of pressurized fluid, at 26, which communicates with the internal duct system.
The orifice 26 is connected to a primary fluid system, generally a closed circuit which recycles the fluid taken from the internal system of the substrate by way of another orifice (not shown), by means of a heat exchanger and a pump, in accordance with a per se conventional technique. The cooling fluid may be water or preferably a suitable inert fluid such as FLUORINERT (registered trademark of 3M Corporation) or GALDEN (registered trademark of MONSANTO Corporation), which are fluorine-bearing liquids that are generally used for cooling radiators of chasses of electronic circuits.
The fluid used may also be a gaseous fluid; the choice of fluid is governed by the amount of heat which is given off and by the capacity of the heat exchanger for discharging the heat which is drawn off in situ.
The pump and the heat exchanger may be common to the whole of the equipment and may supply a plurality of substrates which are designed on the basis of the same principle. Such centralization which is not possible with the radiators of conventional types (which are necessarily individual) ensures a considerable savings with respect to volume and weight for items of equipment which combine a large number of circuits distributed over separate substrates.
The fluid circulation system may be optimized in dependence on the circuit that the substrate is intended to carry. Once the hot spots are located (for example by infra-red thermography), an effort may be made to reduce the thickness of alumina through which the heat has to pass between the hot spot and the closest duct providing for the primary heat exchange effect, that is to say, absorption of the heat in situ. In that way it is possible to design high-power circuits which can operate at elevated ambient temperatures: a maximum operating temperature of 80° to 85° C. and a maximumjunction temperature of 110° to 120° C. limit the maximum temperature difference to about 30°. Levels of performance of that kind may be achieved in the range of power values and the format indicated hereinabove, by virtue of the structure of the invention.
In order to produce the substrate shown in FIG. 1, the process comprises the following steps:
First, deposit on a certain number of layers an evanescent paste (that is to say a paste which will disappear completely in the baking operation, being therefore an ink without any mineral pigment), in accordance with a pattern corresponding to the different segments of ducts to be formed at a given level. The evanescent substance may be a conventional binder such as an unfilled polyvinylbutyral, provided that it is suited to the binder of the ceramic material, that is to say, it does not react therewith.
Second, in the same fashion, deposit of an ink charged with a mineral pigment to form the network of electrical interconnections (such interconnections are denoted by references 31 and 32 for example in FIG. 1).
Third, pierce holes forming interconnections from one layer to another and from a layer to the surface. This may involve either interconnecting the duct segments of the cooling system (the holes are not then metallized) or interconnecting the conductor tracks (the holes are then metallized in conventional fashion).
The layers are then stacked, compressed and sintered. The increased thickness formed at the location where the evanescent paste has been deposited will prevent sintering of the two adjacent layers at that location. In the baking operation, the paste will gradually disappear, leaving a residual volume at the interface between the two layer. It is these residual volumes which together will form the duct segments of the cooling system.
Using this method, it is possible to produce ducts whose maximum thickness is 20 μm) and whose width is of the order of from 1 to 1.5 mm. The total thickness of the substrate is of the order of from 1 to 1.5 mm and the use of the particular type of alumina referred to hereinbefore makes it possible for the fluid to be caused to circulate directly in contact with the alumina, the latter being virtually devoid of porosity (porosity always less than 1 μm).
FIG. 2 shows a second embodiment in which the duct segments are no longer defined at the interface of two adjacent layers but by the removal of material in certain layers of the stack, in accordance with a predetermined pattern. In FIG. 2, for examle, the layers denoted by reference numerals 45 to 48 are perforated in the manner shown in FIGS. 3a to 3d respectively. FIGS. 3b to 3d show in broken lines the pattern of the immediately lower layer so as to more clearly to show the regions through which the fluid may pass from the level of one layer to the next.
If attention is directed to FIG. 3c, it will be noted that two adjacent layers provided with suitable patterns are sufficient to provide for circulation of the fluid. It is preferred however to add additional layers in order to faciliate circulation of the fluid at the locations at which there could be a pressure drop.
The thickness of each of the layers which are perforated may vary between 50 and 250 m. If it is provided that there is always a surface that is common to at least two layers, the flow thickness may thus be of from 0.1 to 0.5 mm, for a width of the order of 1 mm to 2 mm.
Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein. | The invention concerns a monolithic substrate for an electronic power component which is formed by a sintered stack of layers of dielectric material having an internal system of ducts for the circulation of a cooling fluid. The system is a closed system which opens at the surface of the substrate by way of two orifices which respectively provide for the intake of the pressurized fluid into the internal system of ducts and the removal thereof from said system. | 8 |
FIELD OF THE INVENTION
The present invention relates to a process for making microcrystalline cellulose (MCC) from paper grade pulp. More particularly the present invention relates to a process for preparing MCC from unpurified, high pentosan and low alpha cellulose paper-grade pulps.
BACKGROUND OF THE INVENTION
MCC is a purified partially de-polymerized crystalline polymer that has many industrial uses. The known commercial processes for making MCC use partial acid hydrolysis of purified cellulose under conditions, at which only the amorphous areas of the polysaccharides are hydrolyzed, dissolved and removed. The crystalline cellulose areas are not hydrolyzed and can be recovered. The acid hydrolysis process is generally considered completed when a level off degree of polymerization (“LODP”) cellulose product is obtained. As disclosed in U.S. Pat. No. 2,978,446, starting with purified wood celluloses, such an acid hydrolysis produces MCC with the LODP in the range of 50 to 200. As described in O. A. Battista, P. A. Smith, “Microcrystalline Cellulose,” Industrial and Engineering Chemistry, vol. 54, no. 9, p. 24 (September 1962), high alpha cellulose has an average degree of polymerization (DP) of more than 1000 and microcrystalline cellulose has an average DP of about 140 to 190. Also described in S. Rydholm, “Pulping Process,” Textbook of John Wiley & Sons, Inc., pp. 106–07 (1965), the average DP of isolated and purified cellulose ranges from 1000 to as high as 5000 depending on the particular wood species and isolation method. Commercial MCC has been specified in US Pharmacopeia (USP 23 NF 18) to contain not less than 97% cellulose.
In the known conventional MCC processes, purified celluloses, such as purified pulps, are used for preparing MCC. These purified pulps are prepared from wood by prehydrolysis of wood chips under acidic conditions, alkali pulping of the prehydrolyzed wood chips and purification of the resultant pulp. As described in Simmons et al., Tappi, vol. 39, no. 9, pp. 641–47 (1956) and Tappi, vol. 38, no. 3, pp. 178–85 (1955), purified pulp is high in alpha cellulose content, in excess of 97%, and contain low levels of hemicellulose or pentosan impurities, less than 2%. Such purified pulps are also commonly known as dissolving pulps and the described method is still being practiced in the industry. Mention is also made of U.S. Pat. No. 5,589,033, which discloses a process to produce a higher quality dissolving pulp in which the hydrolyzate liquor from the prehydrolysis step is removed from the wood chip-cooking vessel, prior to alkali pulping with sodium sulfide and sodium hydroxide.
Dissolving pulps are relatively expensive to produce and their use greatly increases production costs of MCC. Dissolving pulps may be produced from kraft, soda or sulfite pulp by bleaching and other treatments. Dissolving pulps are used as a starting material for a number of products such as viscous rayon, cellulose esters, cellulose ethers, such as taught in Hyatt et al. U.S. Pat. No. 6,057,438. They are also used to make cigarette tow.
When wood chips are not prehydrolyzed before alkali pulping and purification, as described in Richter, Tappi, vol. 38, no. 3, p. 147 (1955) their alpha cellulose content is less than 90% and pentosan content is as high as 10% for softwoods and 20% for hardwoods. Also from Richter, Table XVI and FIG. 15 , a cold caustic treatment of unbleached softwood kraft pulp could only reduce its pentosan content from 8.6% to 3.2% and any increase in the caustic concentration of the solution beyond 10–12% resulted in pulps with a higher residual pentosan content.
The basic method for preparing MCC from purified pulps was first described in Battista et al., U.S. Pat. No. 2,978,446, which still represents the basis for many conventional MCC manufacturing processes. In Battista et al. '446 the initial step in the process is the repulping of dry dissolving pulp. The repulped material is then acid hydrolyzed with a mineral acid, such as HCl or H 2 SO 4 to dissolve the amorphous cellulose. The material is then dried, milled and bagged. This process is generally performed in a batch-type method.
There are a number of disadvantages with the Battista et al. process and other conventional MCC processes. The starting material is required to be a purified cellulose material that is high in alpha cellulose content. For example, the raw material for a commercially available MCC, Avicel®, is stated to be a special grade of alpha purified wood cellulose. Industrial and Engineering Chemistry, vol. 54, no. 5, pp. 20–28. Thus, it would represent a notable advance in the state of the art if the MCC could be prepared from a pulp that was not required to undergo the expensive purification processes of the prior art, such as directly from a paper-grade pulp.
Attempts in the prior art to employ other than purified celluloses have not been well received due to their inherent deficiencies and poor economics. For example, to produce MCC from partially purified cellulose, with an alpha cellulose content of 92.2%, U.S. Pat. No. 5,543,511 discloses a method for producing MCC using pressurized oxygen and/or carbon dioxide and high temperature conditions. From unpurified cellulosic material, U.S. Pat. No. 5,769,934 describes a steam explosion technique to remove lignin and hemicellulose prior to MCC manufacturing.
For preparing MCC from materials containing lignin, hemicellulose and cellulose, U.S. Pat No. 6,228,213 discloses a combination of reactive extrusion in the presence of basic solution followed by reactive extrusion in the presence of acid. The extrusion in the first step, in the presence of sodium hydroxide, is carried out at temperatures ranging from 140° C. to 170° C. The extrusion in the second step, in the presence of an acid, is carried out at a temperature of 140° C. The final extruded product is bleached with hydrogen peroxide or hypochloride prior to being spray dried into MCC powder.
Additionally, acid depolymerization of cellulosic material is known as an essential step in obtaining MCC in order to remove the amorphous cellulose material. One of the other problems with the prior art processes is that when performed on a commercial scale, the acid depolymerization step used in MCC manufacturing requires large quantities of acid. Sulfuric acid is generally used at 50% concentration in order to depolymerize cellulose pulps. Consequently, a large amount of alkaline agent has also been required to neutralize and wash the hydrolyzate after the acid treatment step. Thus, it would represent a significant advance in the state of the art if a process for producing MCC could be developed where the acid and or alkali agents are readily available and could readily be recycled for reuse.
In attempts to move away from acid treatment steps, the prior art has also explored the possibility of using enzymes and/or microorganisms to produce MCC. For example, the previously mentioned Hyatt et al. '438 patent teaches a process for preparing dissolving grade pulps by a process sequence of caustic extraction, xylanase treatment and caustic extraction to remove xylan from the paper grade pulp. The process increases the high alpha cellulose content of the wood pulp from less than 85% to more than 97% and decreases its hemicellulose impurity from more than 15% to less than 3%. In the two extraction stages, the patent teaches that sodium hydroxide concentrations of not more than 8–12% and temperatures of not less than 50–100° C. need to be employed in order to prevent an undesirable transformation of cellulose I into cellulose II structure.
Zabriskie, U.S. Pat. No. 4,427,778 teaches a process for converting cellulose to MCC using a cellulase enzyme. An example of a use of microorganisms for converting cellulose is found in Kawai et al. U.S. Pat. No. 4,943,532. These methods of using enzymes or microorganisms are expensive and require the addition of another reagent not readily available at a paper plant. Thus, there is a need for a process for producing MCC that can employ paper-grade pulp as the starting material and be readily integrated with an existing paper making-plant.
Mention is also made of U.S. Pat. No. 5,574,150 that discloses a process to produce MCC powder with a good balance between compactibility property and rate of disintegration property. The patent also discloses that products with a low apparent specific volume after tapping were said to be more desirable for the tablet manufacturing in the pharmaceutical industry.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide an improved economical process for producing MCC.
It is another object of the present invention to provide a novel process for producing microcrystalline cellulose from bleached paper-grade pulps. Paper-grade pulps can come from hardwood or softwood species and from kraft or soda pulping process, or their improvements, such as, but not limited to, kraft-AQ, kraft-PS-AQ or soda-AQ pulping processes.
It is a further object of the invention is to produce MCC with particles and bulk density properties better than those obtained from previous processes.
It is still another object of the present invention to provide a process of producing MCC that employs less acid and alkali than previous processes.
It is a still further object of the present invention to produce MCC from dry or never-dry paper pulps.
It is yet another object of the present invention to provide a simple, economical and environmentally friendly process for producing MCC that can be used in a variety of applications.
It is still another further object of the present invention to provide a process for producing MCC that can be integrated with or adjacent to an existing pulp mill.
It is yet still another further object of the present invention to provide a process for producing MCC that can co-produce inorganic chemicals and five carbon sugars.
According to the present invention, the foregoing and other objects are achieved by a process wherein paper-grade pulps are sequentially treated with a basic aqueous solution, washing, and treatment with an acid aqueous solution, washing, texturing and spray drying. Producing five carbon sugars and inorganic chemicals can optionally be achieved by means of membrane filtration of the spent liquors to separate and recover organics and inorganics.
To this end, the present invention provides a process for producing microcrystalline cellulose, the process comprising the steps of: (a) contacting a paper grade pulp with an alkali hydrolysis agent at a temperature ranging from about 25 to about 70° C. and at an alkali hydrolysis agent concentration of at least about 30 weight percent based on the weight of the pulp to alkali hydrolyze the pulp; (b) washing the alkali hydrolyzed pulp to remove excess alkali hydrolysis agent and recovering a washed alkali hydrolyzed pulp; (c) contacting the washed alkali hydrolyzed pulp with an acid hydrolysis agent at a temperature of at least about 80° and at an acid hydrolysis agent concentration ranging from about 25 to about 75 weight percent based on the weight of the washed alkali hydrolyzed pulp to produce an acid hydrolyzed pulp; and (d) washing the acid hydrolyzed pulp to remove excess acid hydrolysis agent and recovering a washed acid hydrolyzed pulp comprising microcrystalline cellulose.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic drawing of a prior art conventional MCC manufacturing process.
FIG. 2 is a schematic drawing of a preferred embodiment of the process for making MCC from paper grade pulp in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The following detailed description illustrates a preferred embodiment of the present invention, however, it is not to be construed to limit the scope of the appended claims in any manner whatsoever.
For comparison purposes, a conventional MCC process is provided in FIG. 1 . Referring to FIG. 1 there is shown dissolving (purified) pulp in a feed tank 2 . The dissolving pulp is fed via a line 4 to a repulping apparatus 6 where the dissolving pulp is mixed with water and repulped. The repulped dissolving pulp is then fed via a line 8 to an acid hydrolysis reactor 10 that is fed with an acid, such as hydrochloric acid or sulfuric acid or a mixture thereof, from a tank 12 through a line 14 . In the acid hydrolysis reactor 10 the amorphous cellulose is dissolved. Typical conditions in the acid hydrolysis reactor include a pulp consistency of about 8%, 50% acid on pulp, residence time of about 60 minutes and a temperature of about 100° C.
The acid hydrolyzed pulp exits via a line 16 into a drum washer 18 . In the drum washer the acid hydrolysis liquor is removed in a line 20 to leave a washed pulp at about 12–15% consistency in the drum washer 18 . The washed pulp is then pressed to 30–35% consistency and removed via a line 32 . The acid hydrolysis liquor is neutralized in tank 22 by addition of lime from tank 24 via a line 26 to a pH of about 7.5 to 8. The neutralized liquor is then removed via a line 28 as effluent 30 .
The washed pulp in a line 32 is then texturized and optionally coated with carboxymethylcellulose (CMC) in stage 34 . CMC in tank 36 is added via a line 38 and blended with the MCC cake at about 40% solids with 8–10% CMC on pulp. Texturization may be effected by twin screw kneading. The texturized MCC is removed via a line 40 and fed to a dryer 42 , such as a spray dryer, fed with aeration gas from source 44 via a line 46 . The spray dried MCC powder is then directed via a line 48 for bagging 50 .
FIG. 2 shows a preferred embodiment of the present invention. A paper grade pulp from a source 102 is used as the starting material. The paper grade pulp can be obtained from a variety of sources as are well known to those skilled in the art. In an especially preferred embodiment, the paper grade pulp feed is a slushed pulp taken directly from an existing bleach plant, such as the last washer stage or high-density storage.
The slushed pulp is fed via a line 104 to an alkali hydrolysis stage 106 . In the alkali hydrolysis the pulp is treated with an alkali treating agent, such as NaOH, from source 108 via a line 110 . Of course other alkali hydrolysis agents well known to those skilled in the art may be employed, such as ammonium hydroxide and potassium hydroxide. The concentration of alkali treating agent is at least about 30 weight percent based on the weight of the slushed pulp, more preferably at least about 40 weight percent. Most preferred is employing sodium hydroxide as the alkali treating agent in a concentration ranging from about 50 to about 100%.
In the alkali hydrolysis step 106 , the use of relatively high concentrations of alkali hydrolysis agent enables substantial dissolution of pentosan and hemicellulose. Additionally, although not required, mercerization of cellulose I to cellulose II can occur during the alkali hydrolysis step. The temperature during the alkali hydrolysis step can range from about 25 to 70° C., more preferably from about 30 to about 60° C., and most preferably is about 40° C. The residence time for the alkali hydrolysis step 14 can vary widely, such as from about 30 to about 120 minutes, preferably about 60 minutes, or an otherwise sufficient amount of time to effect the alkali hydrolysis. The consistency of the pulp during the alkali hydrolysis step preferably ranges from about 3% to about 35% with about 10% being the most preferred.
The alkali hydrolysis agent may be obtained from a variety of sources as is well known to those skilled in the art. In a particularly preferred embodiment of the present invention, the alkali hydrolysis agent is sodium hydroxide and is obtained directly from the pulp mill.
The alkali hydrolyzed pulp product is then directed in a line 112 to a first washing step 114 to remove excess alkali hydrolysis agent and hemicellulose. Any washing apparatus known to those skilled in the art may be employed in the first washing step 114 . Preferred is the use of a two-stage drum washer and wash press. The alkali hydrolysis agent can be recovered, optionally with membrane filtration, to separate out the pentosans and hemicellulose, and sent via a line 118 and returned to the pulp mill 120 , such as to the bleach plant or recovery boiler of the pulp mill to recover five carbon sugars or other inorganic chemicals by methods known to those skilled in the art. Additionally, recovered alkali hydrolysis agent having had the pentosans and hemicellulose removed, can be directly recycled to the alkali hydrolysis step 106 via a line 116 .
The washed alkali hydrolyzed pulp from the washing step 114 is then directed through a line 122 to an acid hydrolysis step 124 . In the acid hydrolysis step 124 the pulp is hydrolyzed by addition of an acid hydrolysis agent from a source 126 via a line 128 . The acid hydrolysis agent can be any of those well known to those skilled in the art, such as, for example, but not limited to, sulfuric acid, hydrochloric acid and nitric acid. The concentration of acid hydrolysis agent can range from about 25 to about 75 weight percent based on the weight of the alkali hydrolyzed pulp with the preferred concentration ranging from about 35 to about 60 weight percent, most preferably about 50%. The temperature for the acid hydrolysis step typically ranges from about 60° C. to about 120° C. with the preferred ranging being between about 85 and about 95° C. The consistency of the pulp in the acid hydrolysis step generally will range between about 3% and about 35% with the preferred consistency being about 10%. The residence time of the acid hydrolysis step is of a sufficient length to allow acid hydrolysis of the product to occur, typically between about 0.5 and about 5 hours with the preferred residence time ranging between about 1 and about 2 hours.
In the acid hydrolysis step 124 , residual pentosans are dissolved and removed from the crystalline cellulose along with any remaining amorphous portion of the cellulose. Acid hydrolysis agent for the acid hydrolysis step can be obtained from any known source 126 . However, in especially preferred embodiments of the present invention, the acid hydrolysis agent may be obtained directly from a paper production plant where it may be available as waste acid from a ClO 2 generator of the pulp mill or acids used in the existing D 1 or D 2 stage of the bleach plant of the pulp mill.
The product from the acid hydrolysis step 124 is fed via a line 130 to a washing step 132 . Washing can be performed in any suitable apparatus known to those skilled in the art. For example, a two-stage drum washer/wash press may be employed. Spent waste acid is removed via a line 136 and can be sent to the pulp mill to use for the pulp bleaching or a paper production plant 138 , known to those skilled in the art. Additionally, the recovered waste acid may be filtered, such as with a membrane filtration step, to remove residual pentosans and amorphous cellulose. The filtered recovered waste acid can be recycled via a line 134 back to the acid hydrolysis step 124 .
The product from the washing step 132 may then optionally be texturized in a texturization step 142 . Texturization is performed according to methods commonly used in the art. Also during the texturization step 132 a coating, such as carboxymethyl cellulose from a source 144 and fed via a line 146 may be applied according to techniques commonly used in the art.
The product from the texturization step 142 is removed in a line 148 and dried in a drying step 150 . Preferably the product is dried with gas from a source 152 and a line 154 . In preferred embodiments, a spray dryer or milling flash dryer can be used. In spray drying, as is known to those skilled in the art, a spray dryer comprised of a vertical cylinder with a conical bottom, sprays a slurry of the MCC into the spray dryer wherein it contacts a hot air stream. The consistency of the MCC in the texturized MCC slurry ranges from about 3% to about 35% with about 16% being the most preferred. Typically, the hot air stream enters at the bottom of the chamber and texturized MCC slurry is sprayed downward. The MCC particles are atomized so that the hot air of the spray dryer is able to contact more surface area of the MCC. The spray dryer generally operates at a temperature above about 100° C. to facilitate evaporation of the water.
When a milling flask dryer is used for the MCC drying, the texturization of MCC prior to its drying is not necessary and the texturization step 142 can be omitted. The conistency of the MCC in the MCC slurry feeding the milling flask dryer ranges from about 10% to about 45% with about 35% being the most preferred.
The dried MCC is removed from the spray dryer 150 in a line 156 and bagged in a bagging step 158 according to techniques commonly used in the art.
EXAMPLES
The following examples are provided to illustrate the present invention. They are not to be construed to limit the appended claims in any manner whatsoever.
Example 1
Vivapour, a commercial powder MCC product of J. Rettenmairer & Sohne of softwood species, was analyzed and found to contain 96.1% cellulose and 3.65% hemicelluloses. The same sample was found to have an intrinsic viscosity of 1.15 dL/g, corresponding to a DP of 138, bulk density of 0.34 gm/cc and of all the particles in the sample, 15.3% is smaller than 38 microns. A similar MCC product of the same company from hardwood species was found to contain 98.5% cellulose and 1.2% hemicelluloses.
Example 2
Aviloid, a commercial MCC powder product from FMC was analyzed and found to have a bulk density of 0.6 gm/cc and 30.3% of all particles of size smaller than 38 microns. The same sample was soaked overnight with water and subsequently centrifuged for 10 minutes at 5000 G centrifugal force to remove all excess water. The residual water content of the resultant sample or water retention value (WRV) was found to be 0.601 grams of H 2 O per grams of dry material.
Example 3
Estercell, a dried commercial dissolving pulp product from IP, was analyzed and was found to contain 97.9% cellulose, 1.93% hemicelluloses, 1.4% pentosan and a WRV of 1.4 g/g. The same pulp sample was also found to have an intrinsic viscosity of 6.16 dL/g, corresponding to a DP of 880. The same dissolving pulp product has been used as the raw material by the MCC manufacturing industry for the making of MCC powder.
Example 4
A dried commercial market paper pulp product from mixed hardwood species from IP, was analyzed and was found to contain 79.1% cellulose, 20.2 % hemicelluloses, 19.3% pentosan and have a WRV of 1.530 g/g and an intrinsic viscosity of 9.12 dL/g, corresponding to a DP of 1357.
Example 5
A dried commercial softwood paper pulp product from IP, was analyzed and was found to contain 85.1 % cellulose, 14.8 % hemicelluloses, 9.3% pentosan and have a WRV of 1.524 g/g. The same pulp sample was found to have an intrinsic viscosity of 6.53 dL/g, corresponding to a DP of 938.
Example 6
100 grams of hardwood paper pulp sample used in example 4 was reslushed with 900 gram water to obtain a pulp suspension of 10% consistency, defined as dry weight of fiber over combined weight of dry fiber plus weight of water. 90 gram of sodium hydroxide was subsequently added to the pulp suspension. The pulp slurry was mixed well, put in a sealed plastic bag and placed in a constant temperature bath at 60° C. for 1 hour. After 1 hour, the pulp slurry was dewatered and well washed to remove all dissolved organics and inorganics from the alkali treated pulp. After dewatering and drying, 86.1 grams of dried solid was obtained from the original 100 grams of paper pulp. The solid material was subsequently analyzed and found to contain 93.8% cellulose, 5.8% hemicelluloses, 3.9% pentosan and have an intrinsic viscosity of 8.83 dL/g. The results indicate that the envisaged alkali treatment stage removes more than 71% of the hemicelluloses in the original pulp. The treatment also increases its cellulose content from 79.1% to as high as 93.8% while having very small impact on its intrinsic viscosity.
Example 7
The experiments of example 6 were repeated at a temperature of 25° C. instead of at 60° C. The solid material yield was 88 grams and its pentosan content was 4.1%. The example results indicate that a decrease in the temperature of the alkali treatment stage from 60° C. to 25° C. has very small impact on the efficiency of the intended hemicelluloses removal process through alkali hydrolysis.
Example 8
Hardwood paper pulp was alkali treated according to example 7. After washing and dewatering, it was reslushed with water to a consistency of 10%. Sulphuric acid was then added to the slurry to obtain an acid charge of 50% weight of acid per weight of alkali treated pulp. The resultant mixture was sealed in a plastic bag and placed in a constant temperature bath at 85° C. for 4 hours. After 4 hours, the slurry was dewatered and well washed to remove all dissolved organics and inorganics from the treated the acid treated solid. After dewatering and drying, 78.5 grams of dried solid, called dried MCC paste was obtained from the original 100 grams of hardwood paper pulp. The dried MCC paste was analyzed and was found to contain 96.6% cellulose, 3.3% hemicelluloses, 3.1% pentosan and intrinsic viscosity of 1.05 dL/l, corresponding to a DP of 125.
Example 9
Experiments in example 8 were repeated at a temperature of 95° C. for 2 hours. The corresponding MCC paste was found to have an intrinsic viscosity of 0.80 and contain 3.0% pentosan. Results indicate that a higher operating temperature can be used to shorten the time require to complete the acid hydrolysis process.
Example 10
The experiments of example 7 and example 8 were repeated. Instead of hardwood paper pulp as described in example 4, softwood paper pulp as described in example 5 was used for these experiments. The solid material yield after the alkali treatment stage was 92.9 grams and the alkali treated material was found to contain 94.5% cellulose, 5.5% hemicelluloses and 2.5% pentosan. After the subsequent acid treatment stage, the solid material yield from the original 100 grams of softwood paper pulp was 84.5 grams. The corresponding dried MCC paste was found to contain 96% cellulose, 4% hemicelluloses, 1.7% pentosan and have an intrinsic viscosity of 0.82 dL/g, corresponding to a DP of 95.
Example 11
Hardwood MCC paste was prepared according to example 9. The solid content of the MCC paste after washing and dewatering from commercial equipment was 16%. A commercial paper pulp repulper device was subsequently used to transform the MCC paste into a milky and viscous slurry of small MCC particles. A commercial spray dryer system was then used to transform the MCC slurry into MCC powder. The dryer was operated with 500° F. at the inlet and 150° F. at the outlet. The resultant dried MCC powder product was found to have an average particle size of 45 microns and powder bulk density of 0.25 g/cm 3 . 69.7% of all MCC particles in the powder product were found to be smaller than 38 microns. The MCC product as prepared was found to have a WRV of 0.33 g/g.
Example 12
Experiments of example 11 were repeated with softwood MCC paste, prepared with softwood paper pulp according to example 10. The resultant dried softwood MCC powder product was found to have an average particle size of 38 microns, including 75.8% of all particles smaller than 38 microns, a powder bulk density of 0.41 g/cm 3 and WRV of 0.34 g/g.
Example 13
Hardwood MCC paste was prepared according to example 9. The solid content of the MCC paste after washing and dewatering from a commercial washpress was 40%. The 40% solid paste was directly fed into a commercial Flash Milling Dryer, operating at 600° F. and 5 psig in the inlet manifold and 180° F. in the outlet. The resultant dried MCC powder was found to have an average particle size of 50 microns and a bulk density of 0.45 g/cm 3 .
The above-mentioned patents are all incorporated by reference. Many variations of the present invention will suggest themselves to those skilled in the art. All such obvious variations are within the full intended scope of the appended claims. | A process for producing microcrystalline cellulose comprised of the steps of contacting a paper grade pulp with an alkali hydrolysis agent, washing the hydrolyzed pulp and contacting the hydrolyzed pulp with an acid hydrolysis agent and washing the acid hydrolyzed product. | 3 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation application of and claims priority to U.S. application Ser. No. 14/266,756, filed on Apr. 30, 2014.
TECHNICAL FIELD
[0002] The subject matter of this application is generally related to composite stadium seats or a seat cushions composed of materials configured in a sandwich construction.
BACKGROUND
[0003] Many venues, such as events at sports and entertainment arenas or stadiums, provide inadequate seating arrangements (e.g., lack of insulation or cushioning), or no seating arrangements at all. For example, seats provided in stadiums or arenas are generally molded hard plastic that provides limited comfort and insulation.
[0004] Besides various medical issues that can arise, an otherwise enjoyable experience of attending such venues can be diminished by inadequate seating arrangements.
SUMMARY
[0005] The present disclosure includes systems and techniques related to portable composite stadium seats or a seat cushions composed of materials configured in a sandwich construction. According to an aspect of the described systems and techniques, a portable composite seat cushion includes a bottom layer including a durable material adapted to provide traction on a bottom surface of the portable composite stadium seat cushion, a core layer including an insulating material, which is different than the durable material, where the insulating material is adapted to provide contoured and cushioned support for sitting on the portable composite stadium seat cushion, and a top layer including a pliable material, which is different than both the durable material and the insulating material, where the top layer is resilient and protects the core layer.
[0006] The foregoing and other embodiments can each optionally include one or more of the following features, alone or in combination. In some embodiments, the portable composite stadium seat cushion can further include a pocket insert that has a cavity with two opposing surfaces, where the pocket insert can be recessed into the core layer, and an attachment pin that can be coupled to the two opposing surfaces of the pocket insert. In some embodiments, the pocket insert can include a load distribution element, where the load distribution element can be embedded, at least in part, within the portable composite stadium seat cushion. In some embodiments, the load distribution element is ring shaped. In some embodiments, the load distribution element can be adapted to absorb tensile loads.
[0007] In some embodiments, the attachment pin can be integral to the pocket insert. In some embodiments, the portable composite stadium seat can include a front face and a rear face opposing the front face, where at least one of the bottom layer, the core layer, and the top layer can be configured such that the portable composite stadium seat is sloped downwards from the rear face towards the front face. In some embodiments, the portable composite stadium seat is rectangular. In some embodiments, the portable composite stadium seat has rounded corners. In some embodiments, the bottom surface of the portable composite stadium seat cushion has a traction pattern. In some embodiments, the pliable material of the top layer is durable, abrasion resistant, and waterproof. In some embodiments, the pliable material of the top layer is neoprene. In some embodiments, the insulating material of the core layer is closed cell foam. In some embodiments, the durable material of the bottom layer is pliable, abrasion resistant, and waterproof. In some embodiments, the durable material of the bottom layer is rubber.
[0008] The systems and techniques described in this specification can be implemented so as to realize one or more of the following advantages. A stadium seat that features ergonomically contoured support for seating comfort and insulation from the surface on which the stadium seat is placed (e.g., insulation from cold or hot surfaces) can be provided. Additionally, a compact and portable stadium seat that can be attached to clothing (e.g., a belt or belt loops) or equipment (e.g., a backpack or a bag) via an attachment device (e.g., a carabineer, a clipping device, or a rope) can be provided.
[0009] Details of one or more implementations are set forth in the accompanying drawings and the description below. Other features, objects and advantages may be apparent from the description and drawings, and from the claims.
DRAWING DESCRIPTIONS
[0010] FIGS. 1A-1F are various views of an example of a composite stadium seat cushion.
[0011] FIGS. 2A-2B are exploded views of an example of a composite stadium seat cushion.
[0012] Like reference symbols in the various drawings indicate like elements.
DETAILED DESCRIPTION
[0013] The portable composite stadium seats or seat cushions described herein are compact, easily transportable, and convenient devices that include various features and qualities that are deficient or not found in other stadium seat cushions. The portable composite stadium seats or seat cushions can provide ergonomic comfort and support in addition to insulating features from temperatures of surfaces on which the composite stadium seat or seat cushion is placed.
[0014] The portable composite stadium seats or seat cushions feature a sandwich structure of materials serving several complimentary functions. The ergonomic features of the composite stadium seat or seat cushion can include a contoured shape that conforms to the human anatomy in the buttocks region and can be sloped downward from the back face of the seat cushion towards the front face of the seat or cushion to facilitate proper back posture when a person is in a seated position. Amongst other possible shapes, the composite stadium seats or seat cushions can be rectangular. In some implementations, the sandwich structure of the composite stadium seat or cushion includes three layers of material, a bottom layer, a top layer, and a core layer sandwiched between the bottom and the top layer.
[0015] FIGS. 1A-1F are various views of an example of a composite stadium seat cushion 100 . In this embodiment, the composite stadium seat cushion 100 includes a bottom layer 130 , a top layer 110 , and a core layer 120 sandwiched between the bottom layer 130 and the top layer 110 .
[0016] The top layer 110 is the element of the composite stadium seat cushion 100 on which a person can be seated. The top layer 110 can be formed from a pliable, durable, abrasion resistant, and/or waterproof material (e.g., neoprene.) The top layer 110 provides resiliency when subjected to continued and periodic use and when exposed to a variety of weather conditions. The top layer 110 partially protects the core layer 120 from exposure to ambient elements and from external contact related impact.
[0017] The core layer 120 is an insulating layer that is adapted to retain the ergonomic shape of the composite stadium seat cushion 100 while providing contoured and cushioned support for sitting on the composite stadium seat cushion. The core layer 120 can provide an insulating barrier from surface temperatures on which the composite stadium seat cushion 100 is placed. In some embodiments, the core layer 120 can be formed from a pliable and thermally insulating material (e.g., closed celled foam).
[0018] The bottom layer 130 can be formed from a pliable, durable, abrasion resistant, and/or waterproof material such as rubber (e.g., rubber used for athletic shoes.) The bottom layer 130 provides resiliency when subjected to continued and periodic use and when exposed to a variety of weather conditions. The bottom layer 130 can also provide traction when placed on a surface and partially protects the core layer 120 from exposure to ambient elements and from external contact related impact. In some embodiments, the bottom layer 130 has a bottom surface with a traction pattern (e.g., similar to traction patterns of shoe soles).
[0019] In embodiments where the composite stadium seat cushion is sloped downward from the back face towards the front face (e.g., in angles of 1°, 2°, 3°, 4°, 5°, or more,) the back face can have a height H 1 (e.g., of 1 inch, 1.25 inches, 1.5 inches, 1.75 inches, 2 inches, 2.25 inches, 2.5 inches, or more) and the front face can have a height H 2 (e.g., of 0.75 inches, 1 inch, 1.25 inches, 1.5 inches, 1.75 inches, 2 inches, or more,) to facilitate proper back posture when a person is in a seated position.
[0020] In some implementations, the composite stadium seat cushion 100 can include a pocket insert 140 and an attachment pin 150 , as shown in FIG. 1B , to attach devices such as a carabineer or a clipping device for transporting the composite stadium seat cushion 100 . In this example, the pocket insert 140 is located at a corner of the composite stadium seat cushion 100 . In other embodiments, the pocket insert 140 can be located at other portions of the composite stadium seat cushion, such as the middle of a shorter one of the sides. The pocket insert 140 can be embedded in the core layer 120 and have a cavity 146 with an opening at one or more outside faces of the composite stadium seat cushion 140 . The cavity 146 can have a height H p (e.g., 0.75 inches, 1 inch, 1.25 inches, 1.5 inches, or more) from the bottom surface 142 to the top surface 144 of the pocket insert 140 to accommodate an attachment device, for example.
[0021] The attachment pin 150 is coupled to the bottom surface 142 and the top surface 144 of the pocket insert 140 such that attachment devices can be hooked onto the attachment pin 150 . In some embodiments, the attachment pin 150 is integral to the pocket insert 140 . In some embodiments, the attachment pin 150 is a component separate from the pocket insert 140 and can be attached to the pocket insert via bolts, screws, rivets, or adhesive, for example.
[0022] In some embodiments, the composite stadium seat cushion 100 includes a load distribution element 148 , as shown in FIG. 2A . The load distribution element 148 provides structural support and form stability for the composite stadium seat cushion 100 . In some embodiments, the load distribution element 148 can be embedded within the core layer 120 . In some embodiments, the load distribution element 148 can be placed between the bottom layer 130 and the core layer 120 , or between the core layer 120 and the top layer 110 of the composite stadium seat cushion 100 . In some embodiments, the load distribution element 148 can be ring shaped.
[0023] The load distribution element 148 can be coupled to the pocket insert 140 providing structural support when the pocket insert 140 is subjected to external loads (e.g., tensile loads) through attachment devices that are coupled with the attachment pin 150 . The material used for the load distribution element can feature tensile and shear strength structural properties to withstand loads the composite stadium seat cushion is designed to endure. For example, when a concentrated tensile load is applied to the pocket insert, which may occur when the attachment device is subjected to a tensile load while the composite stadium seat cushion is constrained in some manner, the load path starts where the attachment pin is coupled with the pocket insert and is dispersed through the load distribution ring. The load path follows the load distribution ring along its longitudinal axis and gradually disperses to the enclosure material (e.g., the bottom, core, and/or top layer) via shear and normal load transfer. The load transfer can be achieved by bonding and geometric interfaces between the contiguous components. In implementations, where loads are transmitted from the load distribution ring to the core layer, the loads can be dispersed to the extent that the shear loads are below the core layer's yield shear values.
[0024] In some embodiments, the load distribution element 148 can be integral to the pocket insert 140 . The load distribution element 148 can be formed from material, such as semi-rigid plastic, that does not crack or rupture when the composite stadium seat cushion 100 is rolled up or subjected to loads that are applied to the composite stadium seat cushion during ordinary use (e.g., sitting on or transporting the composite stadium seat cushion.)
[0025] While the composite stadium seat cushion 100 as shown in FIGS. 1 and 2 is rectangular (e.g., with a width W of 10 inches, 11 inches, 12 inches, 13 inches, 14 inches, or more, and a depth D of 7 inches, 8 inches, 9 inches, 10 inches, 11 inches, or more) with rounded corners, other shapes and configurations are also possible. For example, the composite stadium seat cushion can be circular, oval, triangular, octagonal, hexagonal, etc.
[0026] The described composite stadium seats or seat cushions can be fabricated by well-known methods, including injection molding, laminating, multiple axis milling, and 3D printing. For example, the individual elements of the composite stadium seats or seat cushions, such as the bottom layer, core layer, top layer, pocket insert, attachment pin, and/or load distribution element, can be formed separately, by injection molding. In some embodiments, various elements of the composite stadium seat or seat cushion can be integrally formed. For example, the attachment pin and/or load distribution element can be integral to the pocket insert. FIGS. 2A and 2B illustrate an example of separately formed elements of the composite stadium seats or seat cushions.
[0027] In some embodiments, the top layer 110 can be injection molded from material such as neoprene. The material properties of the molded top layer 110 can include non-marking, weather resistant, and suitable for indoor and outdoor use. The bottom layer 130 can be injection molded from material such as rubber. The material properties of the molded bottom layer 130 can include non-marking, weather resistant, suitable for indoor and outdoor use, and a high durometer or hardness (e.g., comparable to a durometer of rubber found in shoe soles.) In some embodiments, the bottom layer 130 includes a traction pattern on the bottom surface 132 (e.g., a tread like pattern) to provide traction when placed on a surface, as shown in FIGS. 1C, 1E, and 1F .
[0028] The pocket insert 140 and the load distribution element 148 can be injection molded from material such as plastic. The material properties of the molded pocket insert 140 and the load distribution element 148 can include non-marking, weather resistant, and suitable for indoor and outdoor use. In some embodiments, the load distribution element 148 is attached to the center of the pocket insert 140 , as shown in FIG. 2A , to position the attachment location at about the neutral axis of the composite stadium seat cushion 100 . This configuration can reduce eccentric loading that may otherwise cause discomfort or premature wear when seated on uneven surfaces, for example. In some embodiments, the load distribution element 148 is integral to the pocket insert 140 .
[0029] The attachment pin 150 can be injection molded from material such as plastic with properties similar to the pocket insert 140 . The attachment pin 150 can be integral to the pocket insert 140 or a separate component. In embodiments where the attachment pin 150 is a separate component, the attachment pin 150 can be coupled to the pocket insert, for example, via attachment hardware, such as screws, bolts, rivets, etc., or bonded via adhesives. In some implementations, the attachment pin may also be screwed in or inserted into a slot and secured with an adhesive. In some embodiments, the attachment pin 150 can be fabricated from a durable material, such as plastic, fiber reinforced plastic (FRP), steel, or aluminum, for example.
[0030] The core layer 120 can be injection molded from material such as closed cell foam (e.g., medium density closed cell foam.) The material of the core layer 120 can include thermally insulating properties suitable for indoor and outdoor use. The core layer 120 can be lightly compressible to provide comfort, but generally retain its shape to provide structural support for the composite stadium seat cushion 100 . For example, the material of the core layer 120 can feature elastic properties that allow compression with minimal strain or low percentage of deformation from the original shape of the core layer.
[0031] In some embodiments, the pocket insert 140 and/or the load distribution element 148 are embedded in the core layer 120 . The pocket insert 140 and/or the load distribution element 148 can be placed and secured within the mold for the core layer 120 . During the injection molding process of the core layer 120 , the injected material encases, at least partially, the pocket insert 140 and/or the load distribution element 148 .
[0032] The separately fabricated elements of the composite stadium seat or seat cushion can be bonded together, for example by using an adhesive (e.g., cement or adhesive used for bonding components of a shoe to each other.) In the assembled configuration, the top layer 110 and the bottom layer 130 can provide the rigid portion of the composite stadium seat 100 , while the core layer 120 provides the softer portion. This sandwich configuration can provide benefits such as load distribution that results in substantially uniform support when seated on a level or uneven surface and protection from external wear and tear (primarily by the bottom and top layers,) while achieving thermal insulation from surfaces on which the composite stadium seat cushion is placed (primarily by the core layer.)
[0033] It is noted that the described embodiments of a composite stadium seat or seat cushion described herein are exemplary and different variations in structure, design, application and methodology are possible. | The present disclosure includes systems and techniques relating to stadium seats or a seat cushions composed of materials configured in a sandwich construction. In some implementations, an apparatus, systems, or methods can include a durable bottom layer that is adapted to provide traction on a bottom surface of the portable composite stadium seat cushion, an insulating core layer that is adapted to provide contoured and cushioned support for sitting on the portable composite stadium seat cushion, and a pliable top layer that is resilient and protects the core layer. | 0 |
BACKGROUND
Exemplary embodiments relate generally to communications, and more particularly, to methods, systems, devices, and computer program products for implementing condition alert services.
Conditions or events that affect a particular region or group of people can happen unexpectedly. Conditions may be traffic related (e.g., a collision, traffic jam, disabled vehicle), road related (e.g., debris on road, pothole, disabled traffic light), weather related (e.g., severe thunderstorm, flooding), or health and safety related (e.g., chemical spill, terrorist threat), to name a few. Many of these types of conditions go unresolved for an extended period of time. This may be due, in part, to either a lack of knowledge by a governing agency charged with handling the type of condition, or the agency may not fully appreciate the severity of the condition resulting in a delayed response. It may also take significant travel time for the governing agency to arrive at the area in which the condition has occurred. As a result, unsuspecting individuals who are in the region of the condition may find themselves unwittingly face-to-face with it.
Most often, a condition is reported to a governing agency (e.g., police, fire, emergency service providers) by one or more individuals who are first on the scene to discover it. However, other individuals might benefit from obtaining this information at the time of first discovery as opposed to the time in which these individuals arrive in the area of the condition. For example, an individual who receives advance warning of a condition may be in a position to avoid the area in which the condition has occurred. If enough individuals are provided with advanced warning and avoid the region, it would certainly provide a benefit to both the individuals who are notified, as well as the governing agency or first responders who require fast and unobstructed access to the condition.
What is needed, is a way to communicate information concerning conditions at the time of discovery to relevant individuals or entities, such that the individuals or entities can tale action to avoid the condition, and to enable greater access to the condition locations for those who are charged with addressing or resolving the condition.
BRIEF SUMMARY
Exemplary embodiments include methods for implementing centralized condition alert management services. A method includes receiving information elements from a source that identify a condition, aggregating the information elements from the source with information elements from other sources that identify the same condition, and creating a composite file that includes the aggregated information elements representing each of the sources. The method also includes generating a condition alert from the composite file and transmitting the condition alert to a recipient communications device.
Additional exemplary embodiments include systems for implementing centralized condition alert management services. A system includes a host system and a centralized condition alert management application executing on the host system. The centralized condition alert management application implements a method. The method includes receiving information elements from a source that identify a condition, aggregating the information elements from the source with information elements from other sources that identify the same condition, and creating a composite file that includes the aggregated information elements representing each of the sources. The method also includes generating a condition alert from the composite file and transmitting the condition alert to a recipient communications device.
Further exemplary embodiments include computer program products for implementing centralized condition alert management services. A computer program product includes instructions for causing a computer to implement a method. The method includes receiving information elements from a source that identify a condition, aggregating the information elements from the source with information elements from other sources that identify the same condition, and creating a composite file that includes the aggregated information elements representing each of the sources. The method also includes generating a condition alert from the composite file and transmitting the condition alert to a recipient communications device.
Further exemplary embodiments include methods for implementing proximity-based condition alerts. A method includes collecting information elements by a communications device that identify a condition, creating a condition file that includes the information elements and a condition file identifier, and determining a destination address for notification of the condition. The method also includes generating and transmitting a condition alert to the destination address. The condition alert includes the condition file.
Further exemplary embodiments include communications devices for implementing proximity-based condition alerts. A communications device includes a processor unit and a condition alert application executing on the processor unit. The condition alert application implements a method. The method includes collecting information elements that identify a condition, creating a condition file that includes the information elements and a condition file identifier, and determining a destination address for notification of the condition. The method also includes generating and transmitting a condition alert to the destination address. The condition alert includes the condition file.
Other systems, methods, and/or computer program products according to embodiments will be or become apparent to one with skill in the art upon review of the following drawings and detailed description. It is intended that all such additional systems, methods, and/or computer program products be included within this description, be within the scope of the exemplary embodiments, and be protected by the accompanying claims.
BRIEF DESCRIPTION OF DRAWINGS
Referring now to the drawings wherein like elements are numbered alike in the several FIGURES:
FIG. 1 is a block diagram describing a system upon which centralized condition alert management services and proximity-based condition alerts may be implemented in accordance with exemplary embodiments;
FIG. 2 is a block diagram depicting a communications device used in receiving the centralized condition alert management services and for implementing proximity-based condition alerts in exemplary embodiments;
FIG. 3 is a flow diagram describing a process for implementing centralized condition alert management services in exemplary embodiments;
FIG. 4 is a user interface screen for registering for the centralized condition alert management services in exemplary embodiments;
FIG. 5 is a user interface screen for reporting a discovered condition via a communications device in exemplary embodiments;
FIG. 6 illustrate sample databases used by the centralized condition alert management services in exemplary embodiments;
FIG. 7 is a user interface screen depicting a sample condition alert; and
FIG. 8 is a flow diagram describing a process for implementing proximity-based condition alerts in exemplary embodiments.
The detailed description explains the exemplary embodiments, together with advantages and features, by way of example with reference to the drawings.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
Centralized condition alert management services and proximity-based condition alerts are provided in accordance with exemplary embodiments. The centralized condition alert management services provide prompt and targeted notifications of conditions that occur, which can potentially impact a large number of people. By registering for the service and providing user-defined preferences, the centralized condition alert management services process condition information (also referred to as information elements) and directly notify those registered users who have an interest in, or who may be affected by, the condition. The proximity-based condition alerts provide a means for individuals to create and disseminate their own condition alerts to other individuals within a geographic proximity of the condition, thereby providing advance warning of a condition that may affect the individuals who may be en route to, or nearby, a location in the vicinity of the condition. By using proximity-based condition alerts, individuals who may be affected by a condition may benefit from real-time notifications that may enable the individuals to take measures to avoid unnecessary exposure to the condition.
Turning now to FIG. 1 , an exemplary system for implementing the centralized condition alert management services and the proximity-based condition alerts will now be described in accordance with exemplary embodiments. The system of FIG. 1 includes a centralized condition alert management system 100 in communication with one or more communications devices 104 A- 104 C over one or more networks 106 . The centralized condition alert management services are implemented via a host system 102 of the centralized condition alert management system 100 .
The host system 102 may be implemented using a high-speed processing device (e.g., a computer system) that is capable of handling high volume activities conducted via users of the centralized condition alert management system 100 . The host system 102 may be implemented by a network service provider, content service provider, or other enterprise, e.g., as a subscription-based service. The host system 102 executes a centralized condition alert management application (CCAMA) 108 for providing the centralized condition alert management services described herein.
The communications devices 104 A and 104 B represent mobile communications devices, such as cellular telephones, personal digital assistants, or other portable communications devices. As shown in the system of FIG. 1 , the communications device 104 A is a handheld device and communications device 104 B is a device installed in a vehicle. The communications device 104 C represents a stationary communications device that is installed at a fixed location. For example, as shown in FIG. 1 , the communications device 104 C is installed on a utility pole. The communications devices 104 A- 104 C may operate over a wireless data network, using Internet protocols (e.g., TCP/IP) and may also be configured to include global positioning system (GPS) technology as will be described further herein. The communications devices 104 A- 104 C execute a condition alert application 110 for implementing the proximity-based condition alerts described herein. The communications devices 104 A- 104 C may also be configured to access a user interface of the CCAMA 108 , e.g., via the networks 106 , in order to utilize the services provided by the centralized condition alert management system 100 .
The networks 106 may be implemented using wireless networks or any kind of physical network implementation known in the art. The communications devices 104 A- 104 C may be coupled to the host system 102 through multiple networks so that not all of the communications devices 104 A- 104 C are coupled to the host system 102 through the same network. In exemplary embodiments, the communications devices 104 A- 104 C and the host system 102 may be connected to the networks 106 in a wireless fashion. In an exemplary embodiment, networks 106 include peer-to-peer networks that enable direct communication among the communications devices 104 A- 104 C, which are within signal range of one another.
The host system 102 is also in communication with a storage device 112 . The storage device 112 may be implemented using a variety of devices for storing electronic information. It is understood that the storage device 112 may be implemented using memory contained in the host system 102 , or the storage device 112 may be a separate physical device. Information stored in the storage device 112 may be retrieved and manipulated via the host system 102 .
The storage device 112 stores a condition database, a location database, a solution database, and a rules database. In addition, the storage device 112 stores a subscriber alerts database, composite files, and condition alerts and updates as described further herein. The condition, location, solution, and rules databases are shown and described in FIG. 6 . A sample condition alert is shown in FIG. 7 .
Turning now to FIG. 2 , an exemplary communications device 104 will now be described in accordance with exemplary embodiments. The communications device 104 includes a processor unit 202 , an input/output component 204 for initiating and receiving condition alerts, a condition alert application 110 executing on the processor unit 202 , and a communications component 206 . In exemplary embodiments, the processor unit 202 executes the condition alert application 110 for facilitating the proximity-based condition alerts described herein. The input/output component 204 may include elements such as a keyboard and display screen. As described above, the communications device 104 may also be configured to access the user interface of the CCAMA 108 via the communications component 206 in order to utilize the services provided by the centralized condition alert management system 100 . The communications component 206 may be configured to transmit communication signals (e.g., via a transmitter), including condition alerts created by the condition alert application 110 , as well as reporting conditions via the user interface of the CCAMA 108 . The communications component 206 may be configured to detect other communications devices in proximity of the communications device 104 and transmit condition alerts to these other communications devices over a peer-to-peer network (e.g., one of networks 106 ). Likewise, the communications component 206 may be configured to receive condition alerts generated by other communications devices 104 .
In exemplary embodiments, the communications device 104 further includes a recording component 208 , one or more sensors 210 , and a range finder 212 . The components 208 , 210 , and 212 collect information elements relating to a condition. For example, the recording component 208 may comprise a digital image capturing device, a video capturing device, an audio capturing device, or a combination thereof. Depending upon the type of condition that occurs, various measurements may be acquired by the communications device 104 using one or more sensors 210 . For example, temperature readings may be acquired via a temperature gauge. In addition, navigational components may be employed to acquire elevation and azimuth information with respect to a condition. This information may provide point-of-view data that is useful in understanding critical aspects of the condition. For example, the point-of-view data for a condition, such as a fire may indicate the size and scope of the fire, as well as wind direction so that first responders can ascertain which adjacent structures may be impacted by the condition. In exemplary embodiments, the elevation or altitude readings may be acquired by a radar device or a GPS device (i.e., one of the communications components 206 ) using a triangulation calculation technique). Velocity, such as wind speed, may be tracked using an anemometer-type probe. These, and other types of sensors 110 and components, may be utilized in collecting various information elements for a condition alert.
The range finder 212 may be used for calculating a distance between the communications device 104 and the condition. The range finder 212 may be implemented, e.g., using laser, ultrawideband, or other range finding technologies. This information may be useful in accurately identifying a location in which the condition has occurred with greater specificity.
The communications device 104 also includes memory 214 which may be used by the condition alert application 110 when collecting these measurements before reporting a condition alert.
The information elements may be sent to the centralized condition alert management system 100 for processing as described further in FIG. 3 (utilized in the centralized condition alert management services) or may be used to generate a condition alert by the condition alert application 110 (utilized in the proximity-based condition alerts), as described further in FIG. 8 .
The condition alert application 110 may include a user interface configurable via the application 110 . For example, a user interface screen 500 for entering information elements associated with a condition is shown and described in FIG. 5 . Likewise, this type of user interface screen 500 may also be used in reporting a condition to the CCAMA 108 . As indicated above the condition alert application 110 may also include a discovery feature for enabling the user to detect communications devices, such as the communications devices 104 A- 104 C in proximity.
Turning now to FIG. 3 , a process for implementing centralized condition alert management services will now be described in accordance with exemplary embodiments. The centralized condition alert management services utilize various databases, such as databases 600 A- 600 D of FIG. 6 and apply rules to the information therein as described herein. The processes described in FIG. 3 may require that a user register in order to receive the services. A user of the services may register for the services via, e.g., the user interface provided by the CCAMA 108 . A sample user interface screen 400 for subscribing to the services is shown in FIG. 4 . As illustrated in FIG. 4 , a user may register for the services by providing information including preferences for condition alerts. For example, the user may specify a commuting route and approximate times of travel in fields 402 , 404 , and 406 , which identify the geographic area and times in which the user expects to be present in the locations. Thus, should a condition be reported for the location entered by the user and at times close to those entered in the fields 402 , 404 , and 406 , a condition alert would be transmitted to the user accordingly.
Once registered, a subscriber record is created that includes the information provided via the user interface screen 400 and is stored in the subscriber database 600 B as shown in FIG. 6 . In alternative exemplary embodiments, the user may select an automated GPS option via the field 406 , which directs the application 108 to ascertain the user's current location prior to determining whether to transmit a condition alert. For example, if the user's current location is miles away from the condition, a condition alert may not be necessary. In addition, the CCAMA 108 may be configured to periodically ascertain the user's current location, particularly if the condition is severe. Thus, should the CCAMA 108 determine via the GPS that the user is within range of the condition, and the condition is still unresolved, a determination is made to send the condition alert to the user. As shown in the database 600 B of FIG. 6 , a subscriber identifier 610 distinguishes the subscriber record from other records in the database 600 B. A location identifier 612 refers to the current location of the user (if using GPS).
Turning back to FIG. 4 , an alert menu option 408 may be provided, whereupon selection thereof, the user is directed to a new interface screen (not shown) for entering additional preferences (e.g., a communications address to which a condition alert is to be sent if desired). For example, the user may desire to be notified of a condition alert via a particular means, such as cell phone, personal digital assistant, email account, or other desired means. This information may be stored in an alert identification field 614 of the subscriber record of the database 600 B.
Returning now to FIG. 3 , the host system 102 receives information elements from a source (e.g., communications device 104 A) that identify a condition at step 302 . As indicated above, the information elements may be provided via the user interface screen 500 as shown in FIG. 5 . The information elements may include a condition descriptor that identifies the nature of the condition (e.g., pot hole in road, broken traffic light, hazardous debris in road, and chemical spill, to name a few). As shown in FIG. 1 for purposes of illustration, the condition comprises a pothole 116 . This information may be entered, e.g., via a drop down list 508 by selecting a condition type field 502 , or may be manually entered via a description field 504 , followed by selecting a submit option 506 .
In addition, the information elements may include the time of condition discovery, which may be automatically acquired by a clock feature of the communications device 104 A (e.g., a timestamp). Information elements may also include the time of condition occurrence, which indicates the time in which the condition originated as opposed to discovered. The information elements may include the location of the condition, which may be automatically acquired via GPS on the device 104 A or may be manually entered. Additionally, the information elements may include data that identify measurements taken, scope, and magnitude of the condition, positional and angular data identifying a point of view, and distance of the condition with respect to the communications device 104 at the time of information capture. As shown in the user interface screen 500 of FIG. 5 , e.g., a user may select an auto collection feature 516 whereby the sensors 210 and/or range-finder 212 collect various measurements as described above in FIG. 2 . Alternatively, the user may select from one or more categories of measurements via a window 518 and manually enter actual or estimated measurements.
In addition, information elements may include an identification of the communications device 104 that identify the source (e.g., user's cell phone number) and one or more media files capturing media, such as audio, video, and static images of the condition. The user's identification may be optional if the user desires anonymity via a field 522 of the user interface screen 500 . The media files may be captured via the recording component 208 . The user then selects an option 510 to attach a file and selects the file type from a window 512 , followed by the file to be attached from a window 514 . These information elements are transmitted to the CCAMA 108 to report the condition via a submit option 524 . Alternatively, if the user interface screen 500 is used to generate a proximity-based condition alert via the condition alert application 110 , the information elements may be used to create a condition alert by the user of the communications device 104 A as described further in FIG. 8 .
At step 304 , the CCAMA 108 categorizes the information elements by condition type. The condition types may include, e.g., traffic conditions, road conditions, weather conditions, and health and safety conditions. The CCAMA 108 may utilize pre-defined conditions and condition types, as shown in the condition database 600 A of FIG. 6A . For example, the condition database 600 A illustrates condition types in fields 602 and listings of conditions in fields 604 . These condition types are provided by way of example only and are not to be construed as limiting in scope.
In addition, conditions that are reported are mapped to corresponding locations in which the conditions occur. The condition location database 600 C illustrates types of information used in mapping condition information elements to respective condition locations. As shown in FIG. 6 , e.g., the database 600 C illustrates a State identification field 620 including a breakdown by county, city/town, and street. General locations may be defined in the database 600 C as well. For example, familiar or well-known locations may be defined using a field 622 .
At step 306 , the CCAMA 108 aggregates the information elements from each of the sources (e.g., multiple communications devices 104 A- 104 C) that identify the same condition (e.g., the pothole 116 ). For example, the composite file may aggregate measurements taken of the condition from multiple sources in order to clarify the extent or severity of the condition. This may be useful in situations where discrepancies in the information elements occur. Any outliers may be extracted from the composite file. Additionally, the aggregated information elements may be useful where a condition is likely to worsen over time. Aggregated information such as the time of condition discovery by communications devices, such as the communications devices 104 A- 104 C, can be used to compare earlier acquired condition information with later acquired condition information (e.g., image data acquired for a pothole having dimensions that have changed/worsened over time).
At step 308 , the CCAMA 108 creates a composite file that includes the aggregated information elements. For example, the composite file may aggregate measurements taken of the condition from multiple sources in order to clarify the extent or severity of the condition. This may be useful in situations where discrepancies in the information elements occur. Any outliers may be extracted from the composite file. Additionally, this may be useful where a condition is likely to worsen over time. For example, aggregated information such as the time of condition discovery by the communications devices 104 A- 104 C can be used to compare earlier image data of the condition to later image data.
At step 310 , the CCAMA 108 generates a condition alert for the composite file. A sample condition alert 700 is shown in FIG. 7 . As shown in FIG. 7 , the condition alert 700 may include a condition file identifier 702 that identifies the reported condition, a condition type 704 , a time of discovery 706 , location of the condition 708 , and condition details 710 . In addition, if a media file has been captured, the condition alert 700 may include an option 712 to open an attachment that reflects the media file. Additionally, if the source has provided personal information and approval, the condition alert may include an option 714 allowing the recipient of the condition alert 700 to contact the source. Also, the condition alert 700 may include a field 716 that enables the recipient to request validation of the condition. By selecting the option in the field 716 , the CCAMA 108 may utilize updated or confirmed information elements acquired since the time the condition was reported and provide confirmatory or updated information as to the status of the condition over time.
At step 312 , the CCAMA 108 determines a destination address for transmitting the condition alert. The destination address may be determined using the preferences provided in the user interface screen 400 of FIG. 4 as described above. Depending upon the nature and severity of the condition, rules may be applied for determining whether to notify a governing agency (e.g., department of public welfare (DPW), police, fire, ambulance, HAZMAT).
As indicated above, the CCAMA 108 may validate the accuracy and currency of the condition. Thus, at step 314 , the CCAMA 108 validates the accuracy or currency of the information elements in response to a validation request via the field 716 of FIG. 7 .
At step 316 , the CCAMA 108 transmits the condition alert to the destination address(es).
In situations where the centralized condition alert management system 100 services a wide geographic region, it is likely that several concurrent conditions may be reported. The CCAMA 108 may be configured to process condition reports (i.e., information elements) from multiple sources (e.g., the communications devices 104 A- 104 C), as well as for multiple varying conditions. In this scenario, the CCAMA 108 creates multiple composite files for each of the conditions reported. The CCAMA 108 may prioritize the composite files according to a severity level determined for each of the conditions. For example, suppose that a pothole, barn file, and chemical spill have all been simultaneously reported. The CCAMA 108 may assign a severity rating (also referred to herein as priority value) to each of the composite files, such that condition alerts are processed and transmitted to various entities or agencies based upon the severity rating. In this example, the CCAMA 108 may apply rules to the condition information elements and determine a severity rating of 90/100 for the chemical spill based upon the type of material leaked, considered with factors such as the general population of the area in which the condition has occurred. Likewise, a barn fire in a remote area may be ranked at 50/100, while the pothole located on a secondary road and having relatively small dimensions may be ranked as a 10/100. The CCAMA 108 may be configured to process condition alerts for composite files with a severity ranking that exceeds a pre-defined threshold. Sample rules for processing composite files are shown in the rules database 600 D of FIG. 6 as rules 616 .
Turning now to FIG. 8 , a flow diagram describing a process for implementing proximity-based condition alerts will now be described in exemplary embodiments. As indicated above, a user of a communications device (e.g., device 104 A) may generate a condition alert and disseminate the condition alert to any communications devices, such as the communications devices 104 B- 104 C discovered to be in network communication with the communications device 104 A. At step 802 , the user collects information elements via the communications device 104 A and condition alert application 110 . As described above, the information elements may be automatically collected via the sensors 210 or range-finder component 212 of the communications device 104 A by selecting this option 516 from the user interface screen 500 of FIG. 5 . Alternatively, the information elements may be manually entered as described above in FIGS. 3 and 5 . The information elements may include one or more media files as described above in FIGS. 3 and 5 . At step 804 , the condition alert application 110 creates a condition file that includes the information elements and the condition file identifier 702 (shown in FIG. 7 ). The condition file identifier 702 identifies the condition file and optionally, the source of the condition file. At step 806 , the condition alert application 110 determines a destination address for distributing the condition file. As indicated above, the communications device 104 A may be configured to discover other communications devices (e.g., devices 104 B, 104 C), using the communications component 206 over a peer-to-peer network, such as the network 106 . As shown in the user interface screen 500 of FIG. 5 , the user may select an option 520 , which causes the condition alert application 110 to begin searching for a peer communications device. At step 808 , a condition alert (e.g., the condition alert 700 ) is generated and transmitted to the destination address. The condition alert 700 includes the information in the condition file.
As described above, the exemplary embodiments can be in the form of computer-implemented processes and apparatuses for practicing those processes. The exemplary embodiments can also be in the form of computer program code containing instructions embodied in tangible media, such as floppy diskettes, CD ROMs, hard drives, or any other computer-readable storage medium, wherein, when the computer program code is loaded into and executed by a computer, the computer becomes an apparatus for practicing the exemplary embodiments. The exemplary embodiments can also be in the form of computer program code, for example, whether stored in a storage medium, loaded into and/or executed by a computer, or transmitted over some transmission medium, loaded into and/or executed by a computer, or transmitted over some transmission medium, such as over electrical wiring or cabling, through fiber optics, or via electromagnetic radiation, wherein, when the computer program code is loaded into an executed by a computer, the computer becomes an apparatus for practicing the exemplary embodiments. When implemented on a general-purpose microprocessor, the computer program code segments configure the microprocessor to create specific logic circuits.
While the invention has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed for carrying out this invention, but that the invention will include all embodiments falling within the scope of the claims. Moreover, the use of the terms first, second, etc. do not denote any order or importance, but rather the terms first, second, etc. are used to distinguish one element from another. Furthermore, the use of the terms a, an, etc. do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item. | Methods, systems, devices, and computer program products for implementing condition alert services are provided. A method includes receiving information elements from a source that identify a condition, aggregating the information elements from the source with information elements from other sources that identify the same condition, and creating a composite file that includes the aggregated information elements representing each of the sources. The method also includes generating a condition alert from the composite file and transmitting the condition alert to a recipient communications device. | 6 |
FIELD OF THE INVENTION
This invention relates to composite building panels. More specifically, it relates to a method for determining structural parameters of gypsum wallboard.
BACKGROUND OF THE INVENTION
Composite building panels, such as gypsum wallboard, are well known for interior wall and ceiling construction. Some of the main advantages of wallboard over other materials is that wallboard is less expensive, a fire retardant and easy to work with in construction applications. In construction, wallboard is typically secured to wood or metal supports of framed walls and ceilings using fasteners such as nails or screws. Because wallboard is relatively heavy, it must be strong enough to prevent the fasteners from pulling through the wallboard and causing the wallboard to loosen or fall away from the supports.
Nail pull is an industry measure of the amount of force required for wallboard to be pulled away from the associated support and over the head of such a fastener. Preferable nail pull values for wallboard are in the approximate range of between 65-85 pounds of force. Nail pull is a measure of a combination of the wallboard core strength, the face paper strength and the bond between the face paper and the core. Nail pull tests are performed in accordance with the American Society for Testing Materials (ASTM) standard C473-00 and utilize a machine that pulls on a head of a fastener inserted in the wallboard to determine the maximum force required to pull the fastener head through the wallboard. Because the nail pull value is an important measure of wallboard strength, minimum required nail pull values have been established for wallboard. Accordingly, manufacturers produce wallboard that meets or exceeds the minimum required nail pull values.
To ensure that wallboard meets the required nail pull values, conventional wallboard manufacturers adjust the structural parameters of the wallboard. Specifically, manufacturers typically adjust the face paper weight of wallboard having a known core strength value to meet the required nail pull value. During manufacturing, wallboard is tested to determine if it meets the required nail pull value. If the tested nail pull value of the wallboard is less than the required nail pull value, manufacturers increase the face paper weight on the wallboard. This process is repeated until the required nail pull value is met.
Such a process is inaccurate and commonly causes the tested nail pull values to exceed the required nail pull values due to excess face paper weight added to the wallboard. Also, the excess face paper adds weight to wallboard and thereby increases manufacturing and shipping costs of wallboard. Further, there is the likelihood of wasting time and material until the desired nail pull values are achieved on the wallboard production line.
Thus, there is a need for an improved technique of adjusting wallboard manufacturing systems to produce wallboard that meets specified nail pull values.
SUMMARY OF THE INVENTION
These, and other problems readily identified by those skilled in the art, are solved by the present method of determining structural properties of composite building panels such as wallboard.
The present method is designed for determining structural parameters of gypsum wallboard prior to manufacturing to reduce manufacturing and shipping costs as well as significantly reduce manufacturing time.
More specifically, the present method determines structural parameters of wallboard and includes providing a core strength value of the wallboard, determining a required nail pull value and calculating a face paper stiffness value based on the provided core strength value and the determined nail pull value. The calculated face paper stiffness value is displayed on a display device for use by a manufacturer.
In another embodiment, a method of manufacturing wallboard includes determining a required nail pull value, providing a core strength value of the wallboard and determining a face paper stiffness value based on the required nail pull value and the provided core strength value. The method includes determining a face paper weight based on the determined face paper stiffness value, selecting a face paper type based on the determined face paper weight and producing the wallboard using the selected face paper type and the provided core strength value.
Determining the structural parameters prior to manufacturing enables manufacturers to save significant manufacturing and shipping costs by eliminating excess face paper weight that is typically added to wallboard to meet required nail pull values. Additionally, a significant amount of manufacturing time is saved because less time is needed to test the manufactured wallboard to determine the face paper weight needed to meet required nail pull values. Furthermore, the structural integrity and strength of wallboard is maintained, even though the additional weight and stress added by the excess face paper is reduced.
DETAILED DESCRIPTION OF THE DRAWINGS
FIG. 1 is a table illustrating a comparison between measured nail pull data and predicted nail pull data for the same types of wallboard using different face papers.
FIG. 2 is a graph illustrating nail pull as a function of the face paper stiffness at different core strength values.
FIG. 3 is a graph illustrating nail pull as a function of the core strength at different face paper stiffness values.
FIG. 4 is a graph illustrating the relationship between the face paper stiffness and the core strength at different required nail pull values.
FIG. 5 is a graph illustrating the relationship between the face paper weight and the Tensile Strength Index Area (TSIA) values needed to achieve a required nail pull value of 77 lb f at different core strength values.
FIG. 6 is a table identifying certain face paper weight values and Tensile Strength Index Area (TSIA) values needed to achieve a required nail pull value of 77 lb f at different core strength values based on the graph of FIG. 5 .
DETAILED DESCRIPTION OF THE INVENTION
Nail pull values are critical to the strength and usefulness of gypsum wallboard. If a nail pull value for a particular wallboard is too low, the fastener holding the wallboard on a frame or other support can pull through the wallboard and cause the wallboard to crack, break or fall from the frame or support. Alternatively, if nail pull values are too high (i.e., significantly exceed required nail pull values), wallboard production resources are inefficiently applied and money is wasted during manufacturing.
A problem in gypsum wallboard manufacturing is how to accurately determine the face paper weight that correlates to a required nail pull value for wallboard and a way that more efficiently utilizes manufacturing and shipping costs, as well as manufacturing time. As stated above, wallboard manufacturers perform tests on wallboard to determine if it meets a required nail pull value. If the required nail pull value is not met, manufacturers typically increase the face paper weight of the wallboard. These steps are repeated until the required nail pull value of the wallboard is met. This process is not accurate and often causes the wallboard to have excess face paper, which increases the overall weight of wallboard and thereby increases manufacturing and shipping costs as well as manufacturing time.
The present method determines a face paper weight, or alternatively a face paper stiffness value, for wallboard prior to manufacturing that meets the required nail pull value. The method utilizes the following equation that correlates a required nail pull value with the face paper stiffness value and the core strength value of wallboard. The equation is as follows:
Nail Pull (lb f )= a (lb f )+[ b (lb f /(kN/m))×(face paper stiffness (kN/m))]+[ c (lb f /psi)×(core strength (psi))] (1)
where a=4.2126759, b=0.009490606731, c=0.092421774 are constants determined from testing data that best fit the data shown in FIG. 1 .
Prior to manufacturing, the core strength value of wallboard is determined and the required nail pull value is determined for the wallboard to be manufactured (i.e., quarter inch, half inch, etc.). These values are entered in Equation (1) above to determine the face paper stiffness value of the wallboard. For example, the face paper stiffness value for wallboard having a core strength value of 400 pounds per square inch (psi) and a required nail pull value of 77 pound-force (lb.sub.f) is as follows:
77 (lb f )=(4.2126759 (lb f )+[((0.009490606731) (lb f /(kN/m))×(face paper stiffness (kN/M))]+[((0.092421774) (lb f /psi))×(400 psi)]
where the face paper stiffness value=3774 kiloNewton/meter (kN/m).
The face paper stiffness value is a product of the face paper weight and the Tensile Stiffness Index Area (TSIA) value as shown in the following equation:
Face Paper Stiffness (kN/m)=Face Paper Weight (g/m 2 )×TSIA (kNm/g) (2)
Using the above example, the Face Paper Weight for the above wallboard having a core strength value of 400 psi, a required nail pull value of 77 lb f and a TSIA of 26 kiloNewton-meter/gram (kNm/g) is as follows:
Face
Paper
Weight
(
g
/
m
2
)
=
Face
Paper
Stiffness
(
kN
/
m
)
/
TSIA
(
kNm
/
g
)
=
(
3774
kN
/
m
)
/
(
26
kNm
/
g
)
=
145.15
gram
/
meter
squared
(
g
/
m
2
)
In the above equation, the TSIA value is a measurement of the normalized face paper stiffness in all directions on the wallboard. Specifically, an ultrasonic Tensile Stiffness Orientation (TSO®) tester machine measures the Tensile Stiffness Index (TSI) in all directions on the wallboard to determine the TSIA. The stiffer the face paper, the larger the TSIA values. The approximate range of TSIA values for wallboard is 12 to 20 kNm/g.
The face paper stiffness value and TSIA value are used to determine the weight of the face paper that is needed to achieve the required nail pull value for wallboard having a designated core strength value. The calculation for determining the face paper weight is therefore a two-step process of first determining the face paper stiffness and then determining the face paper weight for the wallboard being manufactured.
Equations (1) and (2) are preferably stored in a memory of a computer, personal data assistant or other suitable device. The required nail pull values, core strength values and constants are also stored in the memory in a database or other searchable data format. The memory may be a read-only memory (ROM), random access memory (RAM), compact disk read-only memory (CD ROM) or any other suitable memory or memory device. A user or manufacturer inputs the required nail pull value and designated core strength value for the wallboard into the computer using a keyboard or other suitable input device. Alternatively, the required nail pull value and designated core strength value for the wallboard may be downloaded and stored in a file or folder in the memory. A processor, such as a microprocessor or a central processing unit (CPU), calculates the face paper weight for the wallboard using Equations (1) and (2), the inputted nail pull value and the inputted core strength value. The calculated face paper weight, or alternatively the face paper stiffness value, is displayed to a user on a display device such as a computer screen, monitor or other suitable output device or printed out by a printer. The user uses the calculated face paper weight to select the face paper or face paper type that is to be adhered to the core during manufacturing of the wallboard. The face paper selected using the present method typically reduces the face paper stiffness and weight needed to achieve the required nail pull value compared to conventional wallboard production techniques. Additionally, the present method reduces the overall weight of the manufactured wallboard, which reduces manufacturing and shipping costs. The present method also significantly reduces the manufacturing time associated with producing the wallboard because the intermediate testing of the wallboard to determine if the wallboard meets required nail pull values is no longer necessary.
FIG. 1 is a table that illustrates a comparison between the measured nail pull data and the predicted nail pull data for different wallboard (sample nos. 1-11) using Equation (1). As shown in the table, the predicted average nail pull data using Equation (1) correlates well with the tested or measured average nail pull data of the wallboard. For example, the average tested or measured nail pull value for sample no. 4 was 83 compared to the predicted nail pull value of 82 using Equation (1). Similarly, the tested or measured average nail pull values for sample no. 5, sample no. 6 and sample no. 11 also differ by a value of one compared to the corresponding average predicted nail pull value using Equation (1) (e.g., 82,81; 80,79; 81,80). Furthermore, the predicted nail pull values for sample no. 8 and sample no. 10 wallboard were exactly the same as the corresponding tested or measured nail pull values (e.g., 80,80 and 77,77). Thus, the present method predicts the nail pull values for wallboard with a high degree of accuracy.
Equations (1) and (2) can also be used to predict different structural parameters or values of wallboard to enhance the manufacturing process.
For example, from Equation (1), nail pull data can be expressed as a linear function of the face paper stiffness at different core strength values ranging from 100 psi to 700 psi, as shown in FIG. 2 . The core strength value of wallboard varies based on the type of wallboard being manufactured. The typical range of core strength values for the wallboard considered in FIG. 1 is 400 to 500 psi.
The nail pull data can also be plotted as a linear function of the core strength with the face paper stiffness values ranging from 1000 kN/m to 6000 kN/m, as shown in FIG. 3 . Preferably, the face paper stiffness values range from 2500 to 4000 kN/m for wallboard. In FIGS. 2 and 3 , it is apparent that increasing either the face paper stiffness value or the core strength value of wallboard increases the nail pull value.
FIG. 4 shows a plot of the face paper stiffness value as a function of the core strength value at various different nail pull values. Specifically, line “A” illustrates the relationship between the face paper stiffness values and the core strength values at a target minimum nail pull value of 77 lb f . The ratio of the empirical constants c/b (=9.74) in Equation (1) provides the change in the face paper stiffness values with respect to the change in the core strength values. To maintain the required nail pull value of 77 lb f , a reduction (or increase) of 100 psi in the core strength values corresponds to a 974 kN/m increase (or decrease) in the face paper stiffness values. Furthermore using Equation (2), a higher face paper stiffness value can be accomplished by increasing either the face paper weight or the TSIA.
FIG. 5 illustrates the relationship between the face paper weight and the TSIA that meets a required nail pull value of 77 lb f . The face paper weight requirements for different TSIA values are summarized in the table shown in FIG. 6 . Note that increasing the TSIA value from 14 to 19.5 kNm/g tends to reduce the required face paper weight by an average of 28%, while maintaining the required nail pull value of 77 lb f .
The present method enables wallboard manufacturers to determine important parameters and properties of the wallboard prior to manufacturing such as the face paper weight needed to achieve a required nail pull value. Obtaining these parameters prior to manufacturing helps to significantly reduce manufacturing time, as well as manufacturing costs and shipping costs. The present method also allows manufacturers to maintain the structural integrity and performance of wallboard without adding face paper weight on wallboard.
While several particular embodiments of the present method have been shown and described, it will be appreciated by those skilled in the art that changes and modifications may be made thereto without departing from the invention in its broader aspects and as set forth in the following claims. | A method of determining face paper properties of wallboard including providing a core strength value of the wallboard, determining a required nail pull value based the wallboard specifications and calculating a face paper stiffness value based on the provided core strength value and the determined nail pull value. The method includes displaying the calculated face paper stiffness value on a display device. | 4 |
BACKGROUND OF THE INVENTION
Active regions in a silicon semiconductor substrate are conventionally separated by growing silicon dioxide dielectric in selected regions using the substrate silicon and an oxidizing environment. The active regions are masked with a patterned silicon nitride layer to prevent oxidation. Nevertheless, the silicon dioxide growths extend beneath the edges of the masking silicon nitride layer to form undesired protrusions of silicon dioxide commonly known as the "bird's beak". Investigations directed toward the reduction of the bird's beak have identified that a major contributor to the formation is the thin silicon dioxide pad or buffer layer, which layer is conventionally formed beneath the silicon nitride masking layer to avoid dislocation defect type damage otherwise induced by the thermal coefficient of expansion mismatch between any thick silicon nitride mask and the monocrystalline silicon substrate.
Various techniques for suppressing the lateral movement of oxygen species through the pad layer underneath the silicon nitride mask have been evaluated, with varying degrees of success. For instance, the use rapid thermal nitridation to convert the pad/buffer silicon dioxide (oxide) layer, or merely the native oxide layer, to a graded oxynitride has exhibited relatively good results and is described in co-pending U.S. patent application Ser. No. 07/110,245 (NCR Docket 3967), assigned to the assignee of the present application. Another technique, involving the use of a thin sealing silicon nitride (nitride) layer deposited directly over the native oxide or the nitrided native oxide, was proposed in the article entitled "Selective Oxidation Technologies for High Density MOS" by authors Hui et al., as appeared in the IEEE Electron Device Letters of October 1981. Extensions of the sealed interface localized oxidation (SILO) concept first proposed in the article by Hui et al. are developed in U.S. Pat. Nos. 4,472,459 and 4,551,910. The former patent proposes the deposition of the thin nitride layer on the substrate silicon, without the express formation of an intermediate pad/buffer oxide layer. The implications of the native oxide layer are not addressed. A similar absence of appreciation for the effects of the native oxide is apparent in the teachings of the latter identified patent, where the process expressly prescribes the formation of the nitride layer over the native oxide layer.
Sequential processing in the context of semiconductor fabrication is taught in U.S. Pat. No. 4,438,157, wherein there are described processes for in situ deposition of multiple dielectric layers during the formation of nonvolatile memory devices.
There remains a need for further reducing the bird's beak effect during field oxide growth in silicon semiconductor substrates. The importance of eliminating or substantially suppressing the bird's beak protrusion is evidenced by the major resources being expended to evaluate various trench isolation structures and processes as documented in recent patent and technical literature.
SUMMARY OF THE INVENTION
The invention is directed to a silicon semiconductor fabrication process in which a sealing and masking silicon nitride layer is deposited direct after an etch removal of the native silicon dioxide from the substrate surface. The process focuses on in situ fabrication, during the sequence from the native oxide etch to the nitride deposition, to remove and inhibit the new formation of native oxide.
In one preferred form of its practice the invention involves a furnace tube preconditioning of monocrystalline substrate wafers to an elevated temperature and at a reduced pressure as a prelude to providing a flowing hydrogen chloride (HCl) gas ambient suitable to etch and remove all native oxide. Upon terminating the flow of HCl gas, the furnace tube is evacuated to purge etching residues. The flow of dichlorosilane (SiH 2 Cl 2 ) and ammonia (NH 3 ) gas then commence at a subatmospheric pressure to chemically deposit silicon nitride directly onto the clean silicon substrate surface. The in situ operation ensures that the thin sealing silicon nitride layer used for masking during the field oxidation does not entrap an oxide or oxynitride composition layer at the silicon surface. Tests have established that the in situ etching and deposition sequence provides a sealing nitride layer which when subjected to field oxide growth results in a further reduction of the bird's beak protrusion.
According to an alternate practice of the invention, the in situ etch of the native oxide is performed at elevated temperature and reduced pressure in a hydrogen (H 2 ) environment, followed in succession by the evacuation and the onset of the nitride deposition previously described.
These and other features of the invention will become more apparent upon considering the detailed embodiments which follow.
BRIEF DESCRIPTION OF THE DRAWING
The FIGRURE schematically illustrates an in situ furnace system suitable to perform an etch of native oxide, a purge operation, and a silicon nitride deposition operation.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Numerous different techniques for forming dielectric between active regions in a silicon semiconductor substrate have been considered and tested. The pervasive goal has been to limit the encroachment of the field oxide dielectric into the active regions, commonly referred to as the bird's beak problem, encountered during the selective oxidation of the monocrystalline silicon substrate while the active regions are covered by a masking silicon nitride layer. Given that the bird's beak area subtracts directly from the active area useable for device fabrication, there continues to exist a broadly based desire to further reducing the magnitude of the bird's beak protrusion even in relatively small amounts. On the other hand, those who practice in the technology recognizing that the fabrication refinements which further reduce the bird's beak effect should not materially degrade the characteristics of the devices fabricated in the active regions, nor have a negative impact on fabrication times or costs.
The sealed interface localized oxidation (SILO) process described in the aforementioned article represented a technology which appeared to significantly reduce the bird's beak length in contrast with the classic selective oxidation of silicon process. The present process recognizes the advantage of the SILO process and extends the benefits by further reducing the bird's beak length.
The process is practiced in the context of the apparatus shown in the drawing, where the quartz tube furnace 1, for example, an LPCVD nitride furnace manufactured by Thermco Corporation, is loaded with a semiconductor substrate wafers 2 using boat 3. The tube furnace 1 is sealed by cover 6 to limit access at one end through outlet valve 4, leading by line to a vacuum pump, and accessed at the opposite end through manifold 11 to various sources of gases. The tube furnace pressure is sensed by detector 7 which may if desired regulate the flow rate to the vacuum pump. Heat is provided and regulated by power supply and temperature control 8 operable in con]unction with RF heating coil 9. The gases furnished to tube furnace 1 are mixed in manifold 11. The flow rates of the individual gases, dichlorosilane or silicon, ammonia, and hydrogen or hydrogen chloride, into mixing manifold 11 are controlled by respective electronic mass flow controllers 12, 13 and 14. Valves 16, 17 and 18 fixedly disconnect the respective sources of gas from the mixing manifold 11 and tube furnace 1.
According to one practice of an embodying fabrication sequence, the chamber within tube furnace 1 is first preconditioned by heat from RF coil 9 and evacuation through valve 4 for approximately fifteen minutes. Thereafter, valve 18 is enabled to provide a flow of hydrogen chloride gas through manifold 11 into tube furnace 1. The chamber pressure is stabilized at approximately 100 mTorr by adjusting the evacuation rate of the vacuum pump. During this time the tube furnace chamber temperature is maintained at
approximately 800°-900° C. and the flow rate of hydrogen chloride is held to approximately 25 standard cubic centimeters per minute (sccm). These conditions are thereafter maintained for approximately fifteen minutes to completely remove by etching the 0.5-3 nanometers of native silicon dioxide typically present on monocrystalline silicon wafers 2 exposed to ambient oxidation conditions.
At the conclusion of the fifteen minute etch time, valve 18 is closed and the chamber within tube furnace 1 is evacuated to purge residuals of hydrogen chloride gas and the etch reactants, while maintaining the furnace temperature and seal integrity. This evacuation or purge cycle is continued for a period of approximately fifteen minutes.
Valves 16 and 17 are then opened to permit the flow of ammonia and either dichlorosilane or silane gas into mixing manifold 11, and eventually into the chamber of furnace 1 where wafers 2 reside. The flow of dichlorosilane or silane is regulated by controller 12 to approximately 20 sccm while the flow of ammonia through controller 13 is regulated to approximately 70 sccm. The evacuation rate is adjusted to establish and maintain a chamber pressure of approximately 700 mTorr while retaining the formerly utilized tube furnace chamber temperature of approximately 800°-900° C. The mixture of dichlorosilane of silane with ammonia at the low pressure and elevated high temperature within tube furnace 1 initiates a chemical reaction which deposits silicon nitride onto wafers 2, which wafers 2 were immediately therebefore etched clean of all silicon dioxide.
Under the conditions defined, the nitride is deposited onto the substrate wafers at a rate of approximately two nanometers per minute. Preferably, the low pressure chemical vapor deposition (LPCVD) of the nitride layer is continued for approximately six minutes to form directly onto the clean monocrystalline silicon substrate of wafers 2 a relatively thin sealing silicon nitride layer of approximately 12 nanometers.
Note that the transition from the etch which removes the native oxide to the deposition which forms the sealing silicon nitride layer is undertaken in direct succession, without exposing the wafers to sources of either ambient or chamber oxygen. Consequently, the in situ etching and deposition ensures an ideal junction and bond between the monocrystalline silicon substrate and the masking silicon nitride layer, and the complete elimination of silicon dioxide or oxynitride paths for the movement of oxygen species beneath the nitride layer during field oxide growth.
An alternate embodiment utilizes hydrogen gas in lieu of hydrogen chloride to perform the native silicon dioxide etch operation. According to that practice, the preconditioning evacuation and heating operations are followed by an enablement of flow is enabled through valve 18 to provide hydrogen gas flow at a rate of approximately 25 sccm, while regulating evacuation to maintain a pressure of approximately 100 mTorr and controlling furnace temperature to approximately 800°-900° C. The hydrogen based oxide etch conditions are maintained for a period of approximately fifteen minutes before initiating the next step of a fifteen minute evacuation in preparation for silicon nitride deposition. Again, the in situ transition between the native oxide etch and the silicon nitride deposition eliminates paths for oxygen species during the ensuing field oxide growth operation.
The effectiveness of the seal is best evaluated by considering the relative bird's beak encroachment when growing comparable 700 nanometers layers of field oxide. The encroachment or bird's beak length is defined as the distance from the edge of the masking nitride to the furthest point which the field oxide penetrates under the sealing nitride layer. SILO techniques commonly yield encroachment lengths ranging from 0.45-0.6 micrometers along any edge for the specified 700 nanometers of field oxide. In contrast, in situ sealing of the silicon surface according to the practice of the present invention nominally yields encroachment lengths of 0.25-0.35 micrometers when using a sealing silicon nitride layer of approximately 13 nanometers combined with 40 nanometers of low temperature deposited oxide and either 100 or 140 nanometers of LPCVD silicon nitride. Tests have shown that even further reductions of encroachment can be obtained, to the range of 0.15-0.25 micrometers, by using a combination of such sealing silicon nitride layer at approximately 13 nanometers, a low temperature oxide layer of approximately 30 nanometers and a final nitride mask layer of approximately 100 nanometers.
Cross sectional analyses of the structures also confirm that the transition between the grown field oxide and the active region is relatively gentle, to facilitate step coverage of subsequently formed and patterned conductive layers. | A process for forming a thin sealing layer of silicon nitride directly upon a silicon substrate to minimize bird's beak encroachment. The process employs in situ fabrication whereby the native oxide is removed from the silicon substrate by etching the hydrogen or hydrogen chloride and followed in direct succession, and in the absence of exposure to an oxidizing environment, with the deposition of a silicon nitride layer by LPCVD. Bird's beak encroachment is incrementally reduced by the absence of the native oxide layer as a path for oxygen species movement during the field oxide growth. | 8 |
This invention relates generally to an arrangement for coupling a vent or exhaust hose to the exhaust pipe of a clothes dryer or the like, more particularly to a quick connect tubular device or coupler for such purpose.
BACKGROUND OF THE INVENTION
The literature is bereft of devices which enable quick and simplified coupling of a vent or exhaust hose to the exhaust pipe, for example, of a clothes dryer or the like. A variety of types of coupling means which function to fulfill the general purpose have been known in the art, one of which consists of a circular clamp adapted to attach exhaust hoses to clothes dryer exhaust pipes. One such type consists of a narrow metal band which fits around the exhaust hose and is tightened by turning a machine screw with a screwdriver. Another type is a circular spring clamp which also fits over the hose. The clamps are used to clamp the exhaust hose directly to the exhaust pipe.
It will be appreciated that the described clamps are difficult to use because dryers are manufactured with little working space around the exhaust pipe. Typically, the metallic exhaust pipe at the rear of a dryer terminates flush with the back of the dryer, and the dryer back has a shallow circular depression around the exhaust pipe. In order to use one of these clamps, it is necessary, first of all, that the clamp be put over the hose; then the hose must be placed over the end of the exhaust pipe. The exhaust hose fits over the pipe and, because there is little working room, it is hard to slide the hose onto the pipe to allow secure clamping. Furthermore, after the hose is on the pipe, a clamp must be moved into place and, in the first case cited, the machine screw must be tightened. However, a screwdriver cannot be aligned with the machine screw, because the clamp must be inside the plane of the dryer back in order to clamp the hose on the pipe. Thus, the screwdriver must be held off line to tighten the screw while holding the hose and clamp on the pipe.
As will be understood, the above described procedure is awkward and frequently results in less than secure clamping which allows the hose to slip off later when the dryer is vibrating during an operating cycle. The other type of clamp, that is, the spring clamp noted above must be gripped with a pair of pliers to hold it open while it is being moved into position so as to clamp the hose on the exhaust pipe. This is also a difficult feat which produces the same results as the first type of clamp described.
Other types of coupling devices known in the art are disclosed in U.S. Pat. Nos. 4,708,370 (Todd), 4,746,149 (Thompson), 4,887,852 (Hancock), 4,923,224 (Makris), and 5,109,756 (Barboza et al.).
Of particular note is U.S. Pat. No. 4,708,370, which is concerned with a recreational vehicle discharge pipe coupler and, in particular, discloses a device for coupling a drain pipe to a recreational vehicle discharge pipe fitting of a type having a terminal end portion with a plurality of locking pins extending radially outward from the periphery of the pipe fitting. As such, the female end of the coupling includes corresponding slots which secure about the locking pins by suitable rotation of the female end into mating position with terminal end portion of the discharge pipe. This coupler also utilizes a seal to prevent leakage of the liquid being drained.
U.S. Pat. No. 4,746,149 has a similar scheme to that of U.S. Pat. No. 4,708,370 involving a pair of slot and stud connected units for use between water conduits, such as a garden hose and faucet, an O-ring being provided to prevent escape of water between the units.
Whatever the merits in advantages of the prior devices described, none of them is capable of providing the features in advantages of the present invention. Manifestly, the devices described in the particular noted patents are dependent on having a discharge pipe or the like that is already provided with pins in this totally unavailing for use with a pipe lacking these.
Accordingly, it was a primary object of the present invention to provide a quick connect device that constitutes a simple economical, fast and secure means for coupling or attaching an exhaust hose to the exhaust pipe of a clothes dryer or the like, and also constitutes a means for detaching such hose.
SUMMARY OF THE INVENTION
A primary feature of the present invention resides in the arrangement of a quick connect device for coupling or connecting a vent or exhaust hose to the exhaust pipe of a clothes dryer or the like, the device comprising: a tubular member of unitary construction having a first tubular end female portion and a second tubular end male portion, the first portion having a larger diameter than the second portion, the first portion including magnetic material for engagement with a metallic exhaust pipe of a clothes dryer.
A more specific feature is the provision for a magnetic lining at the inner periphery of the first tubular end female portion for ensuring sliding magnetic coupling of the quick connect device to the exhaust pipe.
Other and further objects, advantages and features of the present invention will be understood by reference to the following specification in conjunction with the annexed drawings, wherein like parts have been given like numbers.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a side view of the quick connect device of the present invention and an exhaust hose;
FIG. 2 is an end view from the large end of the device, that is, from the left end as seen in FIG. 1; and
FIG. 3 is a side wall cross section taken on the line 3--3 to FIG. 1.
DESCRIPTION OF PREFERRED EMBODIMENT
Referring now to the figures of the drawing, there is seen the device of the present invention constituting a simple, fast and secure means of attaching and detaching an exhaust hose to a clothes dryer exhaust pipe or the like.
The quick connect device 10 comprises two portions: portion 10A which surrounds the protruding exhaust pipe of a typical clothes dryer used in the home or for commercial purposes; and portion 10B which has external grooves 12 which typically may be 4/32 of an inch deep and 8/32 of an inch on center to form a suitable thread.
The entire quick connect device can be of plastic, for example, polyvinylchloride (PVC) or other suitable material. However, the interior of the larger portion 10A is provided with magnetic material at its inner periphery. This material may be deployed in a variety of ways; however, as will be seen in FIG. 3, such magnetic material is disposed on the inner peripheral surface of the quick connect device 10 (at the large end or large portion 10A) and extends, for example, for about 13/4" of the axial length of device 10 (as shown in FIG. 3) to a point at which a shoulder 14 is formed. This shoulder acts as a stop device and precludes the penetration of the dryer pipe beyond this point at the interior of the quick connect device.
It will also be noted that the axial extent of the outer periphery of larger portion of 10A is selected in this one example to be approximately two inches, whereas the portion 10B having grooves 12 is selected to be two inches in axial length. With respect to the outer diameter of portion 10A, it would be selected in this example to be approximately 4 and 10/32 of an inch.
The inner diameter of the large portion 10A would be four inches (and including the magnetic ring 16) the magnetic ring being chosen to be 2/32 of an inch in thickness, (the added outer ring surrounding the magnetic ring having a thickness of approximately 3/32 of an inch). The wall thickness of portion 10B would be 6/32 inches including the grooves which are 4/32 of an inch deep. The inner diameter of 10B is 3/32 of an inch.
It will be understood that the dimensions of the quick connect device 10 given above are approximations and can be suitably modified to handle the variety of sizes for clothes dryers that may exist; for example, there may be some dryers with four inch exhaust pipes and others may utilize three inch exhaust pipes.
The procedure for coupling a dryer hose to an exhaust pipe, using the quick connect device, is as follows. The exhaust hose 20, as seen fragmentarily in FIG. 1, is threaded onto the male end, that is, the end of the smaller portion 10B of the device, by turning the quick connect device 10 counter clockwise and allowing the helically wound wire 22 ensconced within the hose 20, and which projects beyond the outer periphery of the exhaust hose 20, to mate with the threads, i.e., the grooves 12 in the quick connect device 10. When the exhaust hose 20 is fully threaded onto the device 10, the hose 20 will be securely attached. Then the large end of the device 10, the female end of the large portion 10A, is slidably extended over the metal exhaust pipe 24 (seen fragmentarily), which is located on the back side of the dryer. The magnetic lining or coating 16 at the inner periphery of portion 10A is of such dimensions as to magnetically engage with and surround the pipe. Since the metal pipe on the clothes dryer has magnetic characteristics, the quick connect device will be held on the metal pipe until removal is desired, at which point a reasonably substantial tug on the quick connect device will cause it to slide off the metal pipe.
It is comtemplated that any conventional exhaust hose can be securely affixed to a dryer exhaust pipe by use of the quick connect device according to the present invention. Some examples of conventional exhaust hoses are flexible aluminum piping, rigid metal piping, and rigid polyvinylchloride (PVC) piping. One preferred exhaust hose is flexible hose formed from a coiled spring imbedded within a plastic casing which follows the helical outline of the coiled spring to cause the drainpipe to assume a corrugated shape.
For what has been described, it will be appreciated that the present invention overcomes the problems inherent in the existing technology. No tools are required and the lack of working space around the dryer exhaust pipe becomes a non-problem. Ordinarily, considerable dexterity is required when using either of the two previously described types of clamps to attach a dryer hose. In contrast therewith, a person with no mechanical talent can easily attach an exhaust hose to a dryer exhaust pipe using the quick connect device of the present invention.
While there has been shown and described what is considered at present to be the preferred embodiment of the present invention, it will be appreciated by those skilled in the art that modifications of such embodiment may be made. It is therefore desired that the invention not be limited to this embodiment, and it is intended to cover in the appended claims all such modifications as fall within the true spirit and scope of the invention. | A quick connect device for coupling a vent or exhaust hose to the exhaust pipe of a clothes dryer or the like, the device having a tubular member of unitary construction with a first, female end portion and a second, male end portion; the first portion including magnetic material for magnetically engaging with a exhaust pipe of dryer, the second portion threadably engaged with an exhaust hose. | 8 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation of copending International Application No. PCT/DE97/00970, filed on May 14, 1997, which designated the United States.
BACKGROUND OF THE INVENTION
Field of the Invention
The invention relates to a turbine shaft which is aligned along a principal axis and includes an inflow region for fluid, and at least two mutually spaced recesses adjoining the inflow region in axial direction for receiving at least one turbine blade in each case. The invention furthermore relates to a steam turbine and a method for cooling an inflow region of a turbine shaft disposed in a turbine, in particular a steam turbine.
German Published, Non-Prosecuted Patent Application DE 32 09 506 A1, corresponding to U.S. Pat. No. 4,571,153, relates to an axial-flow steam turbine, especially one of double-flow construction. In a steam inflow region, an annular passage is formed between the shaft and an annular shaft shield. The shaft has a rotationally symmetrical depression in the steam inflow region. The annular shaft shield projects partially into the depression and is connected to the casing of the turbine through first fixed-blade rows and supported thereby. The shaft shield has conduits for the purpose of introducing steam. The conduits are disposed centrally with respect to the inflow region, between the first fixed blades and they open tangentially into a gap between the rotating shaft and the fixed shield supported by the casing.
German Published, Non-Prosecuted Patent Application DE 34 06 071 A1 discloses an annular shaft shield which is disposed between two rings of the first fixed-blade rows. The shaft shield shields the outer periphery or surface of the turbine shaft from the live steam. The shaft shield has inlets upstream of the rings through which a partial stream of the live steam passes in a restricted manner into a gap between the shaft shield and the turbine shaft. The inlets are angled in such a way that the live steam has a flow component imparted to it in the circumferential direction of the turbine shaft. Auxiliary fixed blades and auxiliary rotating blades can be respectively provided on the inner periphery of the shaft shield and the turbine shaft.
The use of steam at relatively high pressures and temperatures, especially in what are referred to as supercritical steam conditions, with a temperature of, for example, above 550° C., contribute to an increase in the efficiency of a steam turbine. The use of steam in such a condition makes increased demands on a steam turbine that is acted upon in a corresponding manner, particularly on the turbine shaft of the steam turbine.
Patent Abstracts of Japan Publication No. JP 58/133402 describes a double-flow steam turbine which is provided with a chamber construction. Wheel discs which are mounted on the turbine shaft have turbine blades disposed on their respective outer ends. A cover plate disposed in the intermediate region of the turbine shaft into which the working fluid flows, is held by respective first stationary blade rows. The cover plate, which is disposed at the upper end of the wheel discs, forms a non-sealing end for a spatial region, which on one hand is formed by the sides of the wheel discs and on the other hand by the turbine shaft. The wheel discs defining the spatial region have openings for the inflow of working fluid into the spatial region. The openings are sized differently, so that a vacuum is generated in the spatial region and working fluid can flow into the spatial region at least through one wheel disc.
SUMMARY OF THE INVENTION
It is accordingly an object of the invention to provide a turbine shaft which can be cooled in a region subject to high thermal loading, in particular an inflow region for working fluid, and a method for cooling a turbine shaft disposed in a turbine, particularly of an inflow region of the turbine shaft, which overcome the hereinafore-mentioned disadvantages of the heretofore-known devices and methods of this general type.
With the foregoing and other objects in view there is provided, in accordance with the invention, a turbine shaft, comprising an inflow region for working fluid; turbine blades; a shaft body extending along a principal axis and having a shaft surface; the shaft body having at least two recesses formed therein for receiving at least one of the turbine blades in each of the at least two recesses, the at least two recesses spaced apart axially from one another and from the inflow region, and the at least two recesses including a first recess and another recess downstream of the first recess; the shaft body having a cavity formed therein associated with the inflow region; and a feed line and a discharge line connected to the cavity for conducting a partial stream of the working fluid as cooling fluid, the feed line opening at the shaft surface downstream of the first recess and the discharge line opening at the shaft surface downstream of the other recess.
This structure ensures that both the pressure and the temperature of the working fluid are lower in the region of the second recess than in the region of the first recess. If the working fluid used to drive the turbine shaft is used as the cooling fluid for cooling the turbine shaft, this ensures that a flow through the cavity is established purely by virtue of the temperature and/or pressure gradient. The cavity is preferably rotationally symmetrical with respect to the shaft axis.
The cooling of the material of the shaft brings about a significant increase in the bearing capacity of the material and then permits a more rational construction, e.g. the use of conventional, low-cost materials for the shaft, even in the region of very high steam inlet temperatures.
If the turbine shaft is subjected to working fluid, in particular steam in a supercritical steam condition, cooling of the turbine shaft in the inflow region is achieved by feeding cooling fluid into the cavity. The cooling fluid which is fed to the cavity to cool the turbine shaft can be a partial stream from already cooled working fluid, in particular steam, fed to the turbine shaft in the inflow region. In the cavity, the cooling fluid used for cooling is heated by heat transfer. If the cooling fluid corresponds to the working fluid for operating the turbine in which the turbine shaft is disposed, the cavity represents a reheater. The cooling fluid which undergoes reheating therein can be fed to the turbine, in particular the steam turbine, again at any suitable location (as working fluid) or can be removed from it through the use of an extraction location.
In accordance with another feature of the invention, in the case of a turbine shaft for a double-flow turbine, in particular a medium-pressure steam turbine, the inflow region is preferably disposed along the principal axis, in the central region of the turbine shaft. The inflow region additionally serves to divide the inflowing working fluid which drives the turbine. The cavity is preferably recess-turned in the radial direction and is situated between the respective first rotating blade rows in the axial direction.
In accordance with a further feature of the invention, in the case of a single-flow turbine, the inflow region is situated in an end region of the turbine shaft and the discharge line is passed through the casing, back into the steam flow region, for example, specifically downstream of the first recess. This also ensures a pressure and/or temperature difference between the inlet of the feed line and the outlet of the discharge line.
In accordance with an added feature of the invention, the discharge line likewise leads to an extraction location, allowing the cooling fluid flowing out of the cavity to be removed directly from the steam turbine. The end region is preferably constructed as a piston with an enlarged diameter. This piston has a seal which seals off the steam flow region between the turbine shaft and the casing of the turbine. The cavity is preferably formed between the recess for the first rotating blade row and the piston. The discharge line preferably leads from the cavity into the piston and there emerges in the region of the seal.
In accordance with an additional feature of the invention, the feed line and/or the discharge line have a largely axial bore and a largely radial bore. The radial bore leads from the shaft surface into the turbine shaft and enters the axial bore, which extends from the cavity in the axial direction. The diameters of the feed and discharge lines are each matched to the corresponding steam conditions and the desired cooling. In a corresponding manner, the size of the cavity is matched to the required cooling performance.
In accordance with yet another feature of the invention, the cavity is closed by a cover, in particular a cover which is rotationally symmetrical with respect to the shaft axis, and this cover can simultaneously serve as a flow deflection element. The cover is preferably welded to the turbine shaft, ensuring that cooling fluid and working fluid are kept separate in the inflow region. Flow losses due to mixing are thus avoided. In the cavity, the cooling fluid is not in direct contact with the hot working fluid, in particular steam in a supercritical steam condition, striking the outer surface of the cover. The cover serves as a heat exchanger, so that heat is transferred from the turbine shaft to the cooling fluid both through the cover and through the walls of the cavity.
The turbine shaft with cooling in the inflow region of the hot working fluid is particularly suitable in a steam turbine which is supplied with steam in a supercritical steam condition. The steam turbine can be a double-flow medium-pressure turbine section or a single-flow steam turbine. The steam turbine can be cooled, merely by feeding in live steam behind the first rotating blade row, in such a way that reliable operation of the turbine shaft in the case of steam conditions with temperatures above 550° C. is ensured.
With the objects of the invention in view there is also provided a method for cooling an inflow region of a turbine shaft disposed in a turbine, in particular a steam turbine, which comprises providing a turbine shaft with a shaft surface, an inflow region and a cavity associated with the inflow region; providing rotating blade rows including a first rotating blade row; feeding a partial stream of a working fluid as cooling fluid from the shaft surface downstream of the first rotating blade row at a first pressure level; and guiding the partial stream of the working fluid out of the turbine shaft through a discharge line discharging at the shaft surface at a second pressure level lower than the first.
According to the method of the invention for cooling an inflow region in a turbine, in particular a steam turbine, working fluid, in particular steam in a supercritical steam condition, flows as cooling fluid downstream of a first rotating blade row, into a cavity associated with the inflow region and, from there, is led out from the turbine shaft through a discharge line. Heat is thereby released from the inflowing working fluid, wherein that heat has been released to the turbine shaft through the walls of the cavity to the cooling fluid guided into the cavity, ensuring cooling of the turbine shaft. The partial stream of the working fluid which serves as the cooling fluid is removed at a first pressure level in the inflow region and led out of the turbine shaft at a second pressure level lower than the first pressure level. This cooling can be established in a structurally simple manner by forming a corresponding cavity, for example by recess-turning, with an associated discharge line and feed line. Possible influences due to the formation of the cavity with regard to the thermomechanical properties of the turbine shaft are more than compensated for by the cooling which is carried out. The turbine shaft provided with cooling of the inflow region is therefore also particularly suitable for steam in a supercritical steam condition at temperatures of above 550° C.
In particular, in the case of a double-flow medium-pressure turbine section supplied with steam, the cooling fluid is led out of the turbine shaft downstream of a second rotating blade row, which is disposed further downstream than the first rotating blade row. Since there is a pressure and/or temperature gradient between the inflow into the feed line and the outflow from the discharge line, the flow of the cooling fluid through the cavity is maintained without measures to enforce it in the case of a single-flow turbine, in particular a medium-pressure turbine section. The cooling fluid is guided out of the cavity, through an end region of the turbine shaft, through the discharge line into the casing surrounding the turbine shaft. In this case, the cooling fluid can be introduced directly into an extraction location or (as working fluid) back into the steam flow, between the casing and the turbine shaft, downstream of a fixed-blade row further downstream than the first rotating blade row. The partial stream removed from the stream of steam driving the turbine shaft is thus made available again, so that, at worst, the effect on the efficiency of the turbine is slight. Since, in addition, the cooling fluid flowing into the cavity is heated up, with the cavity thus acting as a reheater, it may even be possible to achieve an increase in efficiency.
In accordance with a concomitant mode of the invention, the cavity is supplied with a volume flow of steam of 1% to 4%, in particular 1.5 to 3%, of the total volume flow of live steam driving the turbine shaft. The quantity of steam supplied and serving for cooling depends on individual parameters, such as steam conditions, the materials used and the power rating of the steam turbine system.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a turbine shaft and a method for cooling a turbine shaft, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary, diagrammatic, longitudinal-sectional view of a double-flow medium-pressure turbine section; and
FIG. 2 is a longitudinal-sectional view of a single-flow medium-pressure steam turbine.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now in detail to the figures of the drawings, in which identical reference symbols have the same meaning, and first, particularly, to FIG. 1 thereof, there is seen a portion of a longitudinal section through a double-flow medium-pressure turbine section 15 of a steam-turbine system. A turbine shaft 1 is disposed in a casing 19. The turbine shaft 1 has a shaft body which extends along a principal axis 2 and has a central region 10 with an inflow region 3 for working fluid 4a, in particular steam in a supercritical condition. The casing 19 has a steam inlet 22 associated with the inflow region 3, so that steam flows in between the casing 19 and the turbine shaft 1. The steam is divided into two partial streams in the inflow region 3, as is indicated by flow arrows. The steam turbine 15 has a cavity 7 which is preferably produced by recess-turning and is disposed in the central region 10. The cavity 7 has a side facing the steam inlet 22, which is closed by a cover 11 that is welded to the turbine shaft 1. The cover 11 is arched in the direction of the steam inlet 22, thereby assisting the division of the steam 4a into two partial steam streams. The body of the turbine shaft 1 has recesses 5a and 5b which adjoin the inflow region 3 in the axial direction and are each spaced apart from one another. These recesses 5a, 5b serve to receive turbine blades 6a, 6b forming respective rows 16 and 17 of rotating blades. For the sake of clarity, further recesses and rotating blades disposed therein are not shown. A stationary blade row 21 is provided on the casing 19, in front of each corresponding rotating blade row 16, 17.
An essentially radial bore 14 leading into the interior of the body of the turbine shaft 1 is disposed downstream of the first recess 5a and associated with the partial stream of steam flowing towards the right in FIG. 1. This bore 14 enters an axial bore 13 which opens into the cavity 7. The two bores 14 and 13 form a feed line 8 which connects a surface 12 of the shaft body to the cavity 7 in terms of flow. As a result, part of the steam 4a passes into the cavity 7 downstream of the first rotating blade row 16 in accordance with the flow arrows. A further axial bore 13 leads from the cavity 7 into the body of the turbine shaft 1 on that side of the cavity 7 which lies opposite the feed line 8. This axial bore 13 enters an essentially radial bore 14 which discharges at the shaft surface 12 downstream of the second recess 5b. The latter two bores 13 and 14 form a discharge line 9 through which steam 4b is led back out of the cavity 7 into the partial stream 4a of steam deflected to the left in FIG. 1.
The steam 4b, which serves as a cooling fluid, undergoes reheating in the cavity 7 which is closed off by the cover 11, making it possible to achieve not only cooling of the turbine shaft 1 but also, potentially, an increase in the efficiency of the steam turbine 15. The volume flow of steam 4b guided through the feed line 8, the cavity 7 and the discharge line 9 depends on the amount of heat to be dissipated, the power rating of the steam turbine 15 and other parameters. It can be between 1.5% and 3.0% of the total volume flow of live steam. In order to avoid the turbine blades 6a, 6b disposed to the left and right of the inflow region from being acted upon asymmetrically as a result of the flow of steam through the cavity 7, the total stream of live steam may be divided in a suitable manner into two approximately equal partial streams flowing to the left and to the right. The cooling of the turbine shaft 1 in the inflow region 3 improves its thermomechanical properties and ensures the ability of the turbine shaft 1 to endure even in the case of high-temperature loading of above 550° C.
FIG. 2 shows a longitudinal section of a single-flow medium-pressure steam turbine 15, although only a part above a principal axis 2 is shown for reasons of clarity. The steam turbine 15 has a casing 19, in which a turbine shaft 1 having a body extending along the principal axis 2 is shown. The turbine shaft 1 is sealed off relative to the casing 19 in an end region 18, through the use of a shaft seal 24. The steam 4a for driving the turbine shaft 1 is fed to the steam turbine 15 through a steam inlet 22 and flows essentially along the principal axis 2 through alternately disposed rotating blade rows 16, 17 and fixed-blade rows 21 to an outflow nozzle 23. An inflow region 3 which adjoins the steam inlet 22 lies between the end region 18 and the first rotating blade row 16. In this inflow region 3, the body of the turbine shaft 1 has a cavity 7, which is closed relative to the inflow region 3 by a cover 11. A feed line 8 downstream of the first rotating blade row 16 leads through the body of the turbine shaft 1 to the cavity 7. A discharge line 9 leads from this cavity 7 through the body of the turbine shaft 1 to the shaft seal 24, and from there through the casing 19 to an extraction location 20. There is a temperature and/or pressure difference between the first rotating blade row 16 and the extraction location 20, with the result that steam 4b flows through the feed line 8 into the cavity 7, and from there through the discharge line 9 to the extraction location 20 without additional measures for enforcing this flow. This steam 4b absorbs heat from the turbine shaft 1 through walls, in particular the cover 11, and thus effects cooling of the turbine shaft 1. Due to the absorption of the heat, the steam 4b in the cavity 7 undergoes reheating and can thus continue to be used for the entire steam process, possibly improving efficiency. The feedline 8 and the discharge line 9 can be constructed in a structurally simple manner as bores.
The invention is distinguished by a turbine shaft which has a cavity to which fluid can be fed for cooling, wherein the cavity is disposed in an inflow region subjected to high thermal loading. The cooling fluid fed to the cavity is preferably branched off from the total stream of steam or gas driving the turbine shaft. Continuous flow through the cavity is ensured by connecting the cavity, in terms of flow, to regions in which different pressure and/or temperature conditions of the steam or of the gas prevail. This is brought about without additional compulsory measures. Heat transfer from the turbine shaft to the fluid used for cooling, in particular steam, takes place through the walls of the cavity, as a result of which reliable cooling of the turbine shaft and reheating of the cooling fluid are accomplished. | A turbine shaft includes an inflow region for fluid, in particular steam, and at least two recesses spaced apart axially from one another and from the inflow region, for receiving at least one turbine blade in each case. A cavity in the turbine shaft is associated with the inflow region and is connected to a feed line and a discharge line for fluid for cooling the turbine shaft. A steam turbine and a method for cooling an inflow region of a turbine shaft disposed in a steam turbine, are also described. | 5 |
BACKGROUND OF THE INVENTION
The field of the present invention is motorcycle suspension systems with particular emphasis on cushion arrangement and linkage therefor.
The design of motorcycles today requires spacesaving, compact systems and components in order that the more and more demanding standards and requirements for features, convenience, safety and optimum design can be accommodated. One area toward which efforts have been directed to reduce the overall volume of the components has been in the rear suspension and in the cushion mechanisms associated with the rear suspension. Recent efforts have been undertaken to move the upright cushion members downwardly such that they extend at least partially through the rear wheel support frame adjacent the pivot axis therefor. This has provided some room for other equipment such as batteries, air cleaners, tool boxes and the like. However, the cushion member has still required extension above the rear wheel support frame in order to provide appropriate clearance above the ground and appropriate suspension cushioning. Additionally, added frame structure is necessary to accommodate the loads transmitted through the cushion member from the rear wheel suspension. As a result, such designs have continued to employ a substantial amount of the area behind the engine for the rear wheel suspension mechanisms.
SUMMARY OF THE INVENTION
The present invention is directed to an improved rear suspension system and the spring and damping mechanisms and linkage therefor. Advantageous placement of the cushion mechanism is contemplated for the present invention beneath the rear wheel support frame and extending transversely of the motorcycle. Such an arrangement eliminates the devotion of the space behind the engine and above the rear wheel support frame to the cushion mechanism. Consequently, other components may be positioned therein such as batteries, air cleaners, tool boxes or the like.
In the placement of the cushion member transversely of the motorcycle, linkage has been developed in a further aspect of the present invention for compression and extension of the cushion mechanism with up and down movement of the rear suspension. To this end, two pivotally mounted links extend to either end of the cushion mechanism so as to convert up and down motion into transverse compression and extension. The linkage mechanism is, therefore, associated with both the frame of the motorcycle and the rear wheel support frame so as to be responsive to the relative motion between those components of the motorcycle.
Accordingly, it is an object of the present invention to provide an improved motorcycle rear wheel suspension system. Other and further objects and advantages will appear hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a motorcycle employing the mechanism of the present invention.
FIG. 2 is a side view of the motorcycle of FIG. 1.
FIG. 3 is a perspective view of the rear suspension system.
FIG. 4 is a cross-sectional elevation taken along line 4--4 of FIG. 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Turning in detail to the drawings, a motorcycle is illustrated as including a frame, generally designated 10, an engine 12, a front wheel 14 having a supporting front fork 16 and a rear wheel 18 having a rear suspension, generally designated 20 supporting the rear wheel 18 about an axis at 22. The frame includes a head pipe 24 for receipt of the front fork 16. Extending rearwardly from the head pipe 24 on either side are upper main frame members 26. The upper frame members 26 extend rearwardly and then downwardly as center frame members 28 on either side of the motorcycle. Down tubes 30 extend downardly from the upper frame members 26 to an under carriage 32 extending rearwardly to meet with the center frame members 28. The upper main frame members 26, the center frame members 28, the down tubes 30 and the under carriage 32 generally surround the engine, transmission, cooling system and other associated components. Positioned on the upper main frame members 26 is a gas tank 34. A seat 36 is positioned on a rearwardly extending portion of the frame including a pair of side rails 38 extending rearwardly from the main portion of the frame and back stays 40 extending upwardly from adjacent the intersection of the center frame members 28 and the under carriage 32. Additionally, a handlebar assembly 42 is associated with the front fork 16 and foot pegs 44 are fixed to the under carriage 32.
Looking specifically to FIG. 2, the location of an exhaust system is also illustrated. A front exhaust pipe 46 extends rearwardly beneath the under carriage 32 from the front cylinder or bank of cylinders of the engine 12. A collector 48 is positioned inwardly of the side frame members in a location below the transmission. The tail pipes 50 are illustrated in phantom as extending rearwardly from the collector 48.
The rear suspension 20 of the motorcycle includes a rear wheel support frame 52 including two side bars 54 and 56 having a cross member 58 extending to join the side bars 54 and 56 in front of the rear wheel 18. The side bars 54 and 56 extend rearwardly to support the rear wheel 18 about the axis 22. Forwardly of the cross member 58, the side bars 54 and 56 extend to a horizontal bearing member 60 for pivotally mounting the support frame 52. The horizontal bearing member 60 is located near the lower end of each of the center frame members 28 in an appropriate location for the mounting of the rear suspension. As the cross member 58 is displaced rearwardly from the location of the horizontal bearing member 60 and the side bars 54 and 56 are spaced apart from one another, a vertical passage is defined among these elements. It is within this passage that the cushion mechanism and the linkage therefor are arranged.
The cushion mechanism, generally designated 62, includes a coil spring 64 and a hydraulic damper 66 centered within the coil spring 64. Spring bearing caps 68 and 70 are positioned on the ends of the coil spring 64 and hydraulic damper 66; and a housing 72 surrounds the components between the caps. Outwardly of the spring bearing caps 68 and 70 are mounts 74 and 76. The mounts 74 and 76 are fixed to the damper 66 and the damper rod 78, respectively. Further, the mounts 74 and 76 acting through the spring bearing caps 68 and 70 compress the springs as they are moved toward one another.
As can be seen in each of the figures, the cushion mechanism 62 is arranged transversely of the motorcycle. That is to say, the cushion mechanism 62 is arranged generally parallel to the axis 22 of the rear wheel 18 and to the axis of the horizontal bearing member 60. Its location is sufficiently raised to provide adequate clearance above the ground and yet is totally removed from the area above the rear wheel support frame 52.
To mount the cushion mechanism 62 for cooperation with the rear suspension, linkage means is provided which is fixed to either cushion member mount 74 and 76, the motorcycle frame 10 and the rear wheel support frame 52. Pivotally affixed to the mounts 74 and 76 is a pantograph type mechanism including a first link 80 and a second link 82. The first link 80 is fixed to the mount 74 at one end 84 by means of a pin 86. Similarly, the second link 82 is fixed to the mount 76 at one end 88 by means of a pin 90.
Extending between the center frame members 28 is a frame cross member 92. The first link 80 and second link 82 cross adjacent the frame cross member 92 and are pinned to it so as to pivot about an axis 94 located roughly parallel to the center line of the bike. By pivoting about the axis 94, the first and second links 80 and 82 are able to compress and extend the cushion mechanism 62. The full extent of this compression and extension is contained within a profile that does not exceed the frame width of the motorcycle as graphically illustrated in FIG. 4 where the frame members of the under carriage 32, the foot peg mounting brackets 96 and the foot pegs 44 are illustrated in phantom outwardly of the cushion and linkage assembly.
At the upper ends 97 and 98 of the links 80 and 82, respectively, a mounting means is provided for fixing the links 80 and 82 to move with the rear wheel support frame 52. Because of the nature of the links 80 and 82 and their mounting about the axis 94, relative movement laterally to the movement of the rear wheel support frame 52 must be accommodated. As a result, the mounting means must allow a certain degree of freedom in the lateral direction for the ends 97 and 98. The mounting means found advantageous in the preferred embodiment include two additional links 100 and 102 pivotally mounted to the first and second links 80 and 82, respectively. The pivotal coupling is about pins 104 and 106. By using a pantograph type mechanism, the lateral movement of the ends of the links 80 and 82 are easily accommodated. However, other mechanisms such as rollers on cam surfaces and the like may be employed to the same result.
To affix the links 100 and 102 of the mounting means to move with the rear wheel support frame 52, a mounting bracket 108 is provided. The mounting bracket 108 is pinned for pivotal relative movement to the upper links 100 and 102 by a pin 110. This pin extends roughly parallel to the axis 94 about which the first and second links 80 and 82 are pivotally mounted. The bracket 108 is in turn pivotally mounted to the rear wheel support frame 52 about a transverse axis by a pin 112.
To provide a convenient mounting position for the mounting bracket 108, the rear wheel support frame 52 includes a mounting bridge 114 extending between the cross member 58 and a sleeve 116 positioned about the horizontal bearing member 60. The sleeve 116 extends on the horizontal bearing member 60 between the side bars 54 and 56 as can best be seen in FIG. 4. Thus, the mounting bridge 114 spans the opening created in the rear wheel support frame 52 such that the cushion linkage and cushion mechanism may be disposed within that opening.
Looking specifically to the operation of the system, the linkage mechanism is responsive to the relative movement between the motorcycle frame and the rear wheel support frame by being connected to both of these components. As the rear wheel support frame 52 moves upwardly, the mounting links 100 and 102 are drawn upwardly to cause pivotal rotation of the lower links 80 and 82 about the pivot axis 94. This action in turn compresses the cushion mechanism by inward movement of the ends 84 and 88 of the links 80 and 82. Downward motion of the rear wheel support frame 52 would result in the opposite effect.
The advantageous location of the cushion mechanism and its accompanying linkage is possibly best illustrated in FIG. 2 where it is shown to extend no lower than the exhaust system, is advantageously positioned between the horizontal bearing member 60 and the rear wheel 18 and barely extends upwardly above the top plane of the rear wheel support frame 52. FIG. 2 illustrates the substantial amount of room which is provided, primarily adjacent and rearwardly of the center frame members 28 which had been previously occupied by the cushion mechanism. Again, FIG. 4 illustrates the lateral extent of the mechanism which clearly does not affect the overall width of the motorcycle.
Thus, an advantageous suspension system has been disclosed which provides substantial advantage in its compactness and location. While embodiments and applications of this invention have been shown and described, it would be apparent to those skilled in the art that many more modifications are possible without departing from the inventive concepts herein. The invention, therefore, is not to be restricted except in the spirit of the appended claims. | A suspension system for the rear wheel of a motorcycle employing a transversely mounted cushion member located below the rear wheel support frame of the suspension. Pantograph type linkage is employed to translate vertical relative motion of the rear wheel support frame into horizontal transverse motion actuating the cushion member. The linkage is pinned to both the motorcycle frame and to the rear wheel support frame as well as to the transversely mounted cushion mechanism to achieve the foregoing result. The cushion mechanism itself includes a hydraulic damper and a coil spring concentrically arranged. | 1 |
CLAIM OF PRIORITY
[0001] This application claims the benefit of priority under 35 U.S.C. §119(a) from an application entitled “Method for Transmitting/Receiving Data with Transfer Obligation Delegated in WSN” filed in the Korean Intellectual Property Office on Jul. 25, 2007 and assigned Serial No. 2007-74748, the contents of which are incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a Wireless Sensor Network (WSN) and problems associated unstable link states. More particularly, the present invention relates to the technology of transmitting/receiving data in a WSN.
[0004] 2. Description of the Related Art
[0005] A WSN network differs from the existing conventional networks that have been realized for communication for at least the reason that the WSN has been embodied for the purpose of collecting remote information. The WSN is equipped with a sensor node for processing information collected via a sensor and then transfers processed information, A sink node is used for sending transferred information to outside the network. As a network is constructed of a large number of sensor nodes, the structure of each sensor node should be simply designed. Also, since a certain sensor node may be arranged in an area in which it is difficult for a person to gain access, the sensor nodes should be designed to consume a relatively small amount of electric power so that the sensor node may operate for up to several months or several years from an initial battery without requiring replacement. In addition, the sensor nodes should be designed to have mobility so that each position in which the sensor node has been installed is enabled for free movement. Furthermore, even though some sensor nodes existing within the network might become damaged, the WSN must be embodied so as not to affect the maintenance of the network.
[0006] Meanwhile, IEEE 802.15 Working Group defines the standards for a short-distance wireless network, and in particular, since IEEE 802.15.4 standards defined by the IEEE 802.15 Working Group enables a low-power short-distance wireless network to be commercially realized, the IEEE 802.15.4 standard is raising its head as core technology which is suitable for being applied to a sensor network.
[0007] Further, the WSN based on the IEEE 802.15.4 standard protocol includes proposed methods for transmitting data, respectively corresponding to three different cases.
[0008] FIG. 1 is a conceptual view illustrating the network structure of a WSN based on the IEEE 802.15.4 standard protocol according to the prior art, and FIGS. 2 , 3 , and 4 are flowcharts illustrating the respective processes of a method for transmitting data according to the prior art.
[0009] To begin, in FIG. 1 , the WSN based on the IEEE 802.15.4 standard protocol is constructed in a network structure having a multi cluster form in which a star topology and a peer-to-peer topology are combined. Specifically, the WSN includes: a first cluster CID 1 ( 100 ) realized with a Personal Area Network (PAN) coordinator as the center; a second cluster CID 2 ( 200 ) which includes a first cluster hub CLH 1 linked to a device included in the first cluster CID 1 ( 100 ), and is realized with the first cluster hub CLH 1 as the center; a third cluster CID 3 ( 300 ) which includes a second cluster hub CLH 2 linked to a device included in the second cluster CID 2 ( 200 ), and is realized with the second cluster hub CLH 2 as the center; and a fourth cluster CID 4 ( 400 ) which includes a third cluster hub CLH 3 linked to the second cluster CID 2 ( 200 ), and is realized with the third cluster hub CLH 3 as the center.
[0010] The aforementioned multi-cluster formation includes the PAN coordinator as the center. In the first place, if the PAN coordinator forms the first cluster CID 1 by performing functions, including network settings, beacon transfer, node management, node information storage, and message route setting between connected nodes, devices included in the first cluster CID 1 100 may scan a specified channel list so as to check for a usable communication channel. Then, if a Wireless Personal Area Network (WPAN) IDentification (ID), which is not duplicate, is selected following the completion of scanning, a Full Function Device (FFD), which can directly transmit/receive data, functions as the first cluster hub CLH 1 . Thereafter, if the first cluster hub CLH 1 transmits a beacon frame to other devices, the devices all of which receive the beacon frame are linked to the first cluster hub CLH 1 , and then form the second cluster CID 2 200 . With the repetition of this process, the third and the fourth clusters CID 3 300 and CID 4 400 are embodied, and finally, one WSN is formed.
[0011] Still referring to FIG. 1 , if a device 10 of the first cluster CID 1 100 transmits data up to a device 3 of the second cluster CID 2 200 within the WSN formed as described above, the WSN sets a route for data transfer in the first place. For example, a data transfer route can be set in a sequence, such as CID 1 -10->CID 1 -3->CID 1 -0->CID 1 -6->CID 2 -0->CID 2 -1->CID 2 -3. Namely, in FIGS. 2 , 3 , and 4 , an apparatus for transmitting/receiving data (i.e., a data transmit/receive apparatus) of a departure location may be the device 10 of the first cluster CID 1 illustrated in FIG. 1 , and in FIGS. 2 , 3 , and 4 , a data transmit/receive apparatus existing in a first transit node to a n-th transit node can be either the device 3 of the first cluster CID 1 , the device 0 of the first cluster CID 1 , the device 6 of the first cluster CID 1 , the device 0 of the second cluster CID 2 , or the device 1 of the second cluster CID 2 , illustrated in FIG. 1 . In FIGS. 2 , 3 , and 4 , a data transmit/receive apparatus of a destination can be the device 3 of the second cluster CID 2 200 illustrated in FIG. 1 .
[0012] Hereinafter, with reference to a configuration of the WSN exemplified as above and flowcharts depicted in FIGS. 2 , 3 and 4 , a description will be made in detail of a transfer process relevant to each case.
[0013] Case 1. A Successful Transfer of a Data Frame and Receipt of an ACKnowledgement (ACK) Frame:
[0014] With reference to FIG. 2 , after a transfer route of a data frame is set, the data transmit/receive apparatus of the departure location transmits the data frame to a data transmit/receive apparatus located in the first transit node (step S 11 ), and then waits for a transfer ACKnowledgement (ACK) for a predetermined waiting time (step S 20 ). Before receiving such an acknowledgement, the data transmit/receive apparatus located in the first transit node transmits a data frame to a data transmit/receive apparatus located in the second transit node (step S 12 ). Upon receipt of the data frame, the data transmit/receive apparatus located in the second transit node delivers a data frame to a data transmit/receive apparatus located in the next mode on the transfer route. Subsequently, data transmit/receive apparatuses located in different nodes within the transfer route repeat the above processes, and finally, deliver a data frame to a data transmit/receive apparatus of the destination apparatus (steps S 13 , S 14 , and S 15 ). The data transmit/receive apparatus of the destination generates an ACK frame in reply to the reception of data, and then transmits the generated ACK frame (step S 31 ). Thereafter, the data transmit/receive apparatuses located on the transfer route set during the data transfer deliver the ACK frame to the data transmit/receive apparatuses of the departure location (steps S 32 , S 33 , S 34 , and S 35 ). Finally, if the data transmit/receive apparatus of the departure location receives the ACK frame (from the destination apparatus via the transit nodes) within a predetermined waiting time for which it waits for a transfer ACK, the apparatus at the departure location confirms that data has been successfully transmitted to the destination apparatus (step 840 ).
[0015] Case 2. An Unsuccessful Transfer of a Data Frame
[0016] With reference to FIG. 3 , in the case of unsuccessful transfer of a data frame, by performing steps S 11 to S 13 as in the case described above (i.e., in the case of successful transfer of a data frame shown in FIG. 2 ), data transfer is requested, and waiting for the reception of an ACK frame is implemented (step S 20 ).
[0017] However, a wireless link state of a preset route is unstable, and therefore, a data frame cannot be delivered up to the data transmit/receive apparatus of the destination. Accordingly, the data transmit/receive apparatus of the departure location cannot receive the ACK frame. Therefore, the data transmit/receive apparatus of the departure location fails to receive the ACK frame until a timer is terminated, and repeatedly performs steps S 11 to S 13 for a predetermined number of attempts.
[0018] The data transmit/receive apparatus of the departure location repeats this process up to three times, and if the data transmit/receive apparatus of the departure location cannot receive a special ACK frame, the apparatus of the departure location does not attempt to transmit the data frame again, but instead confirms that the transfer of the data frame has failed (step S 45 ).
[0019] Case 3. The Transfer of a Data Frame Has Been Successful but the Transfer of an ACK Frame Fails
[0020] With reference to FIG. 4 , in a case where the transfer of an ACK frame has failed, as in the case described above (i.e., in the case of successful transfer of a data frame), data transfer is requested by performing steps S 11 to S 15 , and the apparatus at the departure location waits for receipt of an ACK frame as implemented in step S 20 . In addition, in FIG. 4 the ACK frame is transmitted through steps S 31 and S 32 , but fails in transit and does not reach the original sending apparatus.
[0021] However, since a wireless link state of a preset route is unstable, the ACK frame transmitted from the data transmit/receive apparatus of the destination cannot be delivered up to the data transmit/receive apparatus of the departure location.
[0022] Finally, the data transmit/receive apparatus of the departure location fails to receive the ACK frame within the time counted the timer expires. Accordingly, the data transmit/receive apparatus of the departure location, and a data transmit/receive apparatus located on the transfer route repeatedly performs steps S 11 to S 15 . The data transmit/receive apparatus of the departure location repeats this process up to three times, and if it cannot receive a special ACK frame, it does not attempt to transmit the data frame again, but finally confirms that the transfer of the data frame has failed (step S 45 ).
[0023] In order to embody a WSN, the reliability of each data frame transmitted among nodes must be secured. However, in the WSN based on the protocol that the prior IEEE 802.15.4 standard has proposed, as described above, nothing is done, but the re-transfer of a data frame is performed, and an alternative pertinent response to a failure of re-transfer has not been proposed.
SUMMARY OF THE INVENTION
[0024] Accordingly, the present invention has been made in part to solve at least some of the above-stated problems occurring in the art, and to provide some of the advantages as described herein below. The present invention provides a method in which the reliability of data transfer can be guaranteed by delegating the obligation of the data transfer to a data transmit/receive apparatus on a transfer route in a WSN.
[0025] In accordance with an exemplary aspect of the present invention, there is provided a method for transmitting/receiving data with transfer obligation delegated in a Wireless Sensor Network (WSN). The method for transmitting data from a transmitting end to a receiving end through a set transfer route by multiple data transmit/receive apparatuses provided in a Wireless Sensor Network (WSN) which can include the exemplary steps of: (a) performing temporary storage of data to be transmitted on receiving a request to transmit data; (b) transmitting data to a data transmit/receive apparatus which is set as a transfer route and simultaneously request command for forwarding the data to a data transmit/receive apparatus on a next route; and (c) confirming the delivery of the data to the data transmit/receive apparatus set as the transfer route, and then deleting the temporarily stored data frame.
[0026] Preferably, a data transmit/receive apparatus of a departure location, a data transmit/receive apparatus of a destination, and a data transmit/receive apparatus of at lest one transit location existing on a route connecting from the departure location to the destination repeat steps (a) to (c), and then complete data transfer from the departure location to the destination.
[0027] The exemplary method according to the present invention may further include the steps of: waiting for a transfer ACKnowledgement (ACK) for a predetermined waiting time after transmitting the data to the data transmit receive apparatus set as the transfer route; transmitting the transfer ACK to the data transmit/receive apparatus of a source in response to the reception of the data; and deleting the temporarily stored data frame as the transfer ACK is received.
[0028] Preferably, in the step of deleting a temporarily stored data frame, the temporarily stored data frame is deleted if the transfer ACK is received within a period of time during which waiting for the transfer ACK is performed, or in step (c), the temporarily stored data frame is deleted if a predetermined time interval passes after the data is transmitted to the data transmit/receive apparatus set as the transfer route.
[0029] Preferably, a data transmit/receive apparatus provided as a final receiving end transmits a final transfer ACK to a source from which the data frame is transmitted without a process of temporarily storing the data frame if the data frame is delivered to the final receiving end, and the final transfer ACK corresponds to an ACK frame indicating that the transfer of the data frame to a destination is completed.
[0030] In accordance with another exemplary aspect of the present invention, there is provided a method for transmitting data from a transmitting end to a receiving end through a set transfer route by multiple data transmit/receive apparatuses, provided in a Wireless Sensor Network (WSN). The method may includes the steps of: requesting a data transmit/receive apparatus, existing on a next route, to transmit data while transmitting data to a data transmit/receive apparatus which is set as a transfer route; performing temporary storage of transmitted data after the data is transmitted to the data transmit/receive apparatus set as the transfer route; and confirming the delivery of the data to the data transmit/receive apparatus set as the transfer route, and then deleting the temporarily stored data frame.
[0031] In accordance with further exemplary aspect of the present invention, there is provided a Wireless Sensor Network (WSN) system including a data transmit/receive apparatus of a departure location, a data transmit/receive apparatus of a destination, and a data transmit/receive apparatus of at lest one transit location existing on a route connecting from the departure location to the destination. Each data transmit/receive apparatus requests a data transmit/receive apparatus, existing on a next route, to transmit data while transmitting data to a data transmit/receive apparatus which is set as a transfer route, temporarily stores the data, confirms the delivery of the data to the data transmit/receive apparatus set as the transfer route, and then deletes the temporarily stored data frame.
[0032] Preferably, the first data transmit/receive apparatus which has delivered data to the second data transmit/receive apparatus existing on the next route confirms the delivery of the data and then waits for a transfer ACKnowledgement (ACK) for a predetermined waiting time, and the second data transmit/receive apparatus transmits the transfer ACK to the first data transmit/receive apparatus of a source in response to the reception of the data.
[0033] Preferably, the first data transmit/receive apparatus deletes the temporarily stored data frame as the transfer ACK is received from the second data transmit/receive apparatus. More preferably, the first data transmit/receive apparatus deletes the temporarily stored data frame if it receives the transfer ACK within a period of time during which it waits for the transfer ACK.
[0034] Preferably, the first data transmit/receive apparatus may delete the temporarily stored data frame if a predetermined time interval passes after delivering the data to the second data transmit/receive apparatus.
[0035] Preferably, if the data transmit/receive apparatus of the destination receives the data, it transmits a final transfer ACK to a source from which the data is transmitted without temporarily storing the data frame, and the final transfer ACK corresponds to an ACK frame indicating that the transfer of the data frame to the destination is completed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] The above and other exemplary features, aspects, and advantages of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:
[0037] FIG. 1 is a conceptual view illustrating the conventional network structure of a WSN based on the IEEE 802.15.4 standard protocol;
[0038] FIG. 2 is a flowchart illustrating a procedure in a case where data is normally transmitted to a destination in a conventional method for transmitting data;
[0039] FIG. 3 is a flowchart illustrating a procedure in a case where a transmission error of a wireless link is caused in a conventional method for transmitting data;
[0040] FIG. 4 is a flowchart illustrating a procedure in a case where a transmission error of a wireless link is caused in a conventional method for transmitting data;
[0041] FIGS. 5A and 5B show a flowchart illustrating a procedure in a case where data is normally transmitted to a destination in a conventional method for transmitting/receiving data according to an exemplary embodiment of the present invention; and
[0042] FIGS. 6A and 6B show a flowchart illustrating a procedure in a case where a transmission error of a wireless link is caused in a method for transmitting/receiving data according to an exemplary embodiment of the present invention.
DETAILED DESCRIPTION
[0043] Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. The next description includes particulars, such as specific configuration elements, which are only provided for illustrative purposes in order to facilitate a more comprehensive understanding of the present invention, and those of ordinary skill in the art understand and appreciate that prescribed changes in form and modifications may be made to the particulars in the scope of the present invention. For the purposes of clarity and simplicity, a detailed description of known functions and configurations incorporated herein may be omitted when their inclusion may obscure appreciation of the subject matter of the present invention by a person of ordinary skill in the art.
[0044] In the examples provided herein of the present invention, each data transmit/receive apparatus located on a transfer route temporarily stores a data frame, and then delivers the stored data frame to a data transmit/receive apparatus located in the next node. According to examples of this method, by delegating the obligation of data transfer to a data transmit/receive apparatus located in the next node, a data frame is transmitted from a departure location to a destination.
[0045] Hereinafter, a detailed description will be made of a method for transmitting/receiving data according to an exemplary embodiment of the present invention.
[0046] To begin, in order for each device to be able to transmit/receive a data frame, each device must be connected and synchronized with one another via a wireless channel, is assigned an address thereof, and thereby, form a WSN. In an exemplary embodiment of the present invention, it is assumed that a WSN is formed by a method such as proposed in the IEEE 802.15.4 protocol or the Zigbee protocol. Also, it is assumed that a route from a departure location to a destination is set ahead of data transmit/receive in the WSN.
[0047] FIGS. 5A and 5B show a flowchart illustrating examples of a procedure in a case where a data frame is normally transmitted to a destination in a method for transmitting/receiving data according to an exemplary embodiment of the present invention.
[0048] In a method for transmitting/receiving data according to an exemplary embodiment of the present invention, first of all, a data transmit/receive apparatus of the departure location temporarily stores a data frame to be transmitted in a cache memory (step S 111 ). Then, the data transmit/receive apparatus of the departure location transmits the data frame to a first transit node of a preset route (step S 112 ). Thereafter, the data transmit/receive apparatus of the departure location confirms that the data frame has been transmitted to the first transit node, changes a state thereof to a state where it can receive a transfer ACKnowledgement (ACK), enables a timer to operate, and then waits for the transfer ACK during a predetermined period of time (step S 121 ).
[0049] Still referring to FIG. 5A , a data transmit/receive apparatus located in the first transit node receives a data frame which includes a instruction frame necessary to request a data transmit/receive apparatus located in the next node (i.e., a second transit node) of the transfer route to transmit a data frame. Hence, in order to transmit the data frame to the data transmit/receive apparatus located in the second transit node, the data transmit/receive apparatus located in the first transit node temporarily stores the data frame (step S 131 ). In addition, the data transmit/receive apparatus located in the first transit node transmits a first ACK frame to the data transmit/receive apparatus of the departure location (step S 132 ), where the first ACK frame confirms that the data transmit/receive apparatus located in the first transit node has received the data frame. Thus, once the first transmit node receives the data frame and confirms receipt, the data transmit/receive apparatus of the departure location receives the first ACK frame while counting a reply waiting time, confirms that the data has been stably transmitted to the data transmit/receive apparatus located in the first transit node, and then deletes the temporarily stored data frame (step S 122 ). Thus, the amount of time spent by the departure apparatus waiting for a reply is significantly shortened.
[0050] Further, the data transmit/receive apparatus located in the first transit node transmits a data frame to a data transmit/receive apparatus located in a second transit node (step S 133 ), and then waits for a transfer ACK from the data transmit/receive apparatus located in the second transit node (step S 141 ). If that happens, the data transmit/receive apparatus located in the second transit node temporarily stores the data frame (step S 151 ), and then transmits a first ACK frame to the data transmit/receive apparatus located in the first transit node (step S 152 ). In the meantime, the data transmit/receive apparatus located in the first transit node, which receives the first ACK frame in a process of waiting for a transfer ACK, deletes the temporarily stored data frame (step S 142 ).
[0051] As shown in FIG. 5B , until a data frame is delivered to a data transmit/receive apparatus of the destination, each data transmit/receive apparatus located on the transfer route repeats a process (step S 153 ) of transmitting a data frame, a process (steps S 161 and S 181 ) of waiting for a transfer ACK, a process (steps S 162 and S 182 ) of deleting temporarily stored data, and a process of performing temporary storage of data following the reception of data (step S 171 ) and then transmitting a first ACK frame (step S 172 ).
[0052] Subsequently, if the data frame is finally delivered to the data transmit/receive apparatus of the destination (step S 173 ), the data transmit/receive apparatus of the destination refers to a destination address included in the data frame, and then confirms that the data frame corresponds to data that is finally delivered to itself.
[0053] The temporary storage of a data frame is performed by the transmission apparatus and the first to nth transit nodes so as to delegate the transfer obligation of the data frame to the next transit node. However, the data transmit/receive apparatus of the destination need not transmit a data frame to another device any more (it the data has reached its destination), and accordingly does not have to perform the temporary storage of the data frame. Thus, it is preferable (but not required) that the data transmit/receive apparatus of the destination does not temporarily store a received data frame for a special use.
[0054] Also, each data transmit/receive apparatus located on the transfer route transmits a first ACK back to a node which has transmitted a data frame to it in order to indicate that it receives the data frame between nodes. However, desirably, the data transmit/receive apparatus of the destination generates a second ACK necessary to give notice that the data frame has finally been transmitted to the destination, and then transmits the generated second ACK to a source which transmits data to it (step S 190 ).
[0055] FIGS. 6A and 6B show a flowchart illustrating a procedure in a case where a transmission error of a wireless link is caused in a method for transmitting/receiving data according to an exemplary embodiment of the present invention.
[0056] The exemplary method for transmitting/receiving data depicted in FIGS. 6A and 6B is the same as the method described above with reference to FIGS. 5A and 5B . However, there is the difference between the two methods in that the transfer of a data frame fails due to an unstable wireless link state between specific nodes. Namely, the method for transmitting/receiving data depicted in FIGS. 6A and 6B corresponds to a case where data transmitted from a second transit node is not delivered to another node located on a next transfer route.
[0057] Now referring to FIGS. 6A and 6B , following the reception of a data frame from a first transit node, a data transmit/receive apparatus located in the second transit node temporarily stores the received data frame in a cache memory (step S 151 in FIG. 6A ), and then transmits a first ACK (step 8152 FIG. 6A ) to a data transmit/receive apparatus located in the first transit node. In addition, the data transmit/receive apparatus located in the second transit node transmits the above data frame to a node located on a next transfer route (step S 153 ), and then waits for a transfer ACK for a predetermined time interval (step S 161 ).
[0058] However, as shown in FIG. 6B , since a state of a wireless link between the second transit node and a node (e.g., a third transit node) located on a next transfer route is unstable, the transfer of the data frame fails. Accordingly, as a waiting time interval during which the second transit node waits for the transfer ACK expires, the second transit node does not receive a separate first ACK. After all, the second transit node considers the data transfer unsuccessful to retransmit data temporarily stored in the cache memory (step S 153 ), and then waits for a transfer ACK again (step S 161 ).
[0059] Nevertheless, as the state of the wireless link between the second transit node and the node (e.g., the third transit node) located on the next transfer route is not yet stable, the transfer of the data frame fails again. If that happens, the second transit node cannot receive a separate first ACK within a waiting time interval during which it waits for the transfer ACK, and then considers the data transfer unsuccessful. Thereafter, the second transit node retransmits the data temporarily stored in the cache memory (step S 153 ), and then waits for a transfer ACK again (step S 161 ).
[0060] Now, in the case where the unstable state of the wireless link between the second transit node and the node (e.g., the third transit node) located on the next transfer route becomes stable, and accordingly, the transfer of a data frame up to the node located on the next transfer route is successful. With this, the node located on the next transfer route temporarily stores the received data frame (step S 171 ), and then transmits a first ACK frame to the second transit node (step S 172 ). If that happens, the second transit node that waits for the transfer ACK receives the first ACK frame at this point in time, and then confirms the successful transfer of the data frame to delete the temporarily stored data frame (step S 162 ).
[0061] Further, in an exemplary embodiment of the present invention, a data frame is temporarily stored in a cache memory before delivering the data frame to a data transmit/receive apparatus located on a next transfer route. Performing temporary storage of a data frame in a cache memory is for reading in a temporarily stored data frame to retransmit the read data frame if the data frame is not transmitted up to a data transmit/receive apparatus located in a next node on a route. Hence, the present invention is not limited to storing a data frame ahead of the transfer of the data frame. Namely, it is also possible that a data frame is stored after the data frame is transmitted to a data transmit/receive apparatus located in a next node on a route.
[0062] Still further, a data transmit/receive apparatus transmits a data frame to a data transmit/receive apparatus located on a next route up to a predetermined number of times, and determines that the transfer of the data frame failed if the predetermined number of times has been exceeded. Herein, the predetermined number of times corresponds to the number of times determined by experience or an experiment, and can be a predetermined number of times determined in consideration of how many times transfer can be successful through re-transfer when the transfer of a data frame fails in a network. In the present invention, it is exemplified that a predetermined number of times corresponds to a definite number of times, but the present invention is not limited to this. For example, the number of times can be adjusted in consideration of wireless link states among data transmit/receive apparatuses.
[0063] Also, in an exemplary embodiment of the present invention, after a data frame is transmitted to a data transmit/receive apparatus located on a next route, a transfer ACK is received and then a temporarily stored data frame is deleted. However, the present invention is not limited to this. For instance, if it is determined that the transfer of a data frame has failed, since a data transmit/receive apparatus does not transmit a data frame any longer, the data transmit/receive apparatus can delete a temporarily stored data frame. In another aspect, regardless of whether it is successful to transmit the data frame up to the data transmit/receive apparatus located on the next route, it is also possible to delete the temporarily stored data frame after a prescribed time interval passes.
[0064] According to a method for transmitting/receiving data of the present invention as described above, even though a link state between specific nodes among transfer routes used to transmit data is unstable and accordingly the transfer of a data frame fails, without the necessity of transmitting data from the data transmit/receive apparatus of a departure location again, the data frame can be transmitted within a section where the transfer of the data frame fails. Also, the data transmit/receive apparatus of the departure location to a destination does not have to wait for a transfer ACK until a data frame is completely transmitted up to a destination. Therefore, a transfer ACK waiting time of the data transmit/receive apparatus of the departure location can be significantly reduced.
[0065] Furthermore, if each data transmit/receive apparatus sequentially and repeatedly transmits multiple data frames, it needs not wait for a transfer ACK over a long waiting time interval until the transfer of the next data frame begins after a single data frame is completely transmitted from the departure location to the destination. Namely, when it is successful to deliver up to the next node on the transfer route, the next data frame can be transmitted immediately.
[0066] While it is exemplified that a WSN is formed in a method proposed in the IEEE 802.15.4 protocol or the Zigbee protocol in an exemplary embodiment of the present invention, the present invention is not limited to this, if a WSN for data transmit/receive is embodied, that will do.
[0067] Some of the advantages and effects of the exemplary embodiments of the present invention, and typical/preferable configurations to operate as described above, will be described as follows.
[0068] According to a method for transmitting/receiving data of the present invention, as a waiting time interval during which each data transmit/receive apparatus waits for a transfer ACK is reduced, the transmission efficiency of data thereby increases, and electric power required in data transfer can also be reduced. Also, if multiple data frames are sequentially and repeatedly transmitted, the next data frame can be transmitted immediately when data transfer between nodes is completed, and accordingly, the time required to complete data transfer of multiple frames can be reduced.
[0069] While the invention has been shown and described with reference to certain exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention. Therefore, the spirit of the present invention and the scope of the appended claims are not limited to the exemplary embodiments shown and described herein above.
[0070] For example, a predetermined interval can be the same for each of the transit nodes, or within a predetermined range of time. Moreover, each of the transit nodes may repeats sending a data frame for a predetermined number of times, and that number can be the same or vary according to each node. | A method for transmitting/receiving data with transfer obligation delegated in a Wireless Sensor Network (WSN) reduces the time and power spent by a transmitting apparatus to wait for acknowledgment that a data transfer was successful. The method for transmitting data from a transmitting end to a receiving end through a set transfer route by multiple data transmit/receive apparatuses provided in a Wireless Sensor Network (WSN), typically includes the steps of: performing temporary storage of data to be transmitted on receiving a request to transmit data; requesting a data transmit/receive apparatus, existing on a next route, to transmit data while transmitting data to a data transmit/receive apparatus which is set as a transfer route; and confirming the delivery of the data to the data transmit/receive apparatus set as the transfer route, and then deleting the temporarily stored data frame. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a stator sub-assembly, a stator assembly, a motor using the same, and a manufacturing method of the stator assembly.
2. Description of the Related Art
A stepping motor has been extensively used as a motor used for a rotating component and the like of an OA apparatus or an automobile. The stepping motor converts a digital electric input into a mechanical motion in response to electric signals and rotates stepwise by a fixed angle for each step, thus attaining a high accuracy in positioning. One type of such a stepping motor is a PM (permanent magnet) stepping motor using a permanent magnet in a rotor section thereof.
A conventional PM stepping motor is provided with a stator assembly 100 as shown in FIG. 10 . The stator assembly 100 comprises two stator subassemblies 101 and 101 attached back to back.
FIG. 11 shows an exploded view of one of the two stator subassemblies 101 and 101 . The stator sub-assembly 101 comprises a cylindrical cup-shaped outer stator yoke 102 , an inner stator yoke 103 made of a ring-shaped steel plate and a winding 104 .
The outer stator yoke 102 and the inner stator yoke 103 are formed such that after punching out their respective soft magnetic materials, their respective plurality of pole teeth 102 a and 103 a are intermeshed, with a gap. The winding 104 is formed by winding a magnet wire W around a flanged bobbin 105 made of plastic resin The flanged bobbin 105 includes a terminal block 107 protruding from its cylindrical flange substantially perpendicularly to its axial direction, and has a plurality of terminal pins 106 projecting from the terminal block 107 and fixed thereto. Lead wires of the winding 104 are hooked around the terminal pins and soldered. The terminal pins 106 are connected to a driving circuit of an apparatus on which the stepping motor is mounted.
A cutout 102 b is formed in the outer stator yoke 102 in order to allow the terminal block 107 protrude outward. Referring to FIG. 12 , a width of the cutout 102 b is set to be substantially equal to a width of the terminal block 107 , thereby securely fixing the winding 104 within coupled stator subassemblies 101 and 101 .
The stator assembly 100 is formed such that the two stator subassemblies 101 and 101 each having the above-described structure are, for example, resin-molded with one another with their respective inner yokes in contact. Here, the two stator subassemblies 101 and 101 are coupled such that their respective plurality of pole teeth are misaligned by an optical electrical angle, for example, 90 degrees.
However, when the stator assembly 100 is structured as described above, a displacement in a relative electrical angle between the two kinds of pole teeth has to be adjusted, causing a dislocation between the two terminal blocks opposite to each other to occur as shown in FIG. 11 . Consequently, it is difficult or complicated to make a smooth electrical connection between the stepping motor provided with the above-described stator assembly 100 and an apparatus on which the stepping motor is mounted.
For example, in case of connecting the terminal pins 106 with a flexible printed circuit (FPC) 109 having connection holes 108 as shown in FIG. 12 , it is necessary to make such a special design as to boring rather big connection holes due to the dislocation between the two terminal blocks opposite to each other. However, enlarging the connection holes involves defects such as incomplete soldering, thereby diminishing the reliability of soldering.
In brief, the conventional stator assembly 100 has a defect in that the dislocation between the two terminal blocks 107 and 107 opposite to each other can occur, causing the defects of the electrical connection between the motor having the stator assembly 100 and the apparatus on which the motor is mounted, eventually diminishing the manufacturing reliability of the stator assembly and the motor.
SUMMARY OF THE INVENTION
The present invention has been made in the light of the above, and its object is to provide a stator sub-assembly, a stator assembly, and a motor which allow them to have their respective smooth electrical connections with an apparatus on which they are mounted and also to provide a method of manufacturing a highly-reliable stator.
In order to achieve the above object, according to a first aspect of the present invention, a stator sub-assembly comprises:
a coil bobbin composed of a cylinder having a winding. of a magnet wire therearound, and a terminal block provided with terminal pins connected to lead wires of the winding; and
coupled stator yokes housing the coil bobbin therein and having a cutout for allowing the terminal block to protrude therethrough, the cutout having a width adapted to allow the terminal block to circumferentially shift rotatably about a center of an axial direction of the coil bobbin.
In the first aspect of the present invention, a first angle made by two radii connecting a center of the coupled stator yokes to both circumferential ends of the terminal block may be set to be smaller than a second angle made by two radii connecting the center of the coupled stator yokes to both circumferential ends of the cutout.
In the first aspect of the present invention, the first angle may be set to be smaller than the second angle by an electrical angle of at least 10 degrees.
According to a second aspect of the present invention, a stator assembly comprises two stator subassemblies, wherein
the two stator subassemblies each comprise: a coil bobbin composed of a cylinder having a winding of a magnet wire therearound, and a terminal block provided with terminal pins connected to lead wires of the winding; and coupled stator yokes housing the bobbin therein and having a cutout for allowing the terminal block to protrude therethrough, the cutout having a width adapted to allow the terminal block to circumferentially shift rotationally about a center of an axial direction of the coil bobbin; and
the two stator sub-assemblies are disposed such that respective terminal blocks of the two stator sub-assemblies abut on each other.
In the second aspect of the present invention, a first angle made by two radii connecting a center of the coupled stator yokes to both circumferential ends of the terminal block may be set to be smaller than a second angle made by two radii connecting the center of the coupled stator yokes to both circumferential ends of the cutout.
In the second aspect of the present invention, the first angle may be set to be smaller than the second angle by an electrical angle of at least 10 degrees.
In the second aspect of the present invention, the respective terminal blocks of the two stator sub-assemblies may be positioned so as to be circumferentially overlapped each other.
In the second aspect of the present invention, the terminal block may have a positioning mechanism.
In the second aspect of the present invention, respective coupled stator yokes of the two stator sub-assemblies may be disposed such that respective pole teeth of the respective coupled stator yokes are misaligned relative to each other by a predetermined electrical angle.
According to a third aspect of the present invention, a motor has a stator assembly according to the second aspect of the present invention.
According to the fourth aspect of the present invention, a method of manufacturing a stator assembly includes two stator sub-assemblies each comprising: a coil bobbin composed of a cylinder having a winding of a magnet wire therearound and a terminal block provided with terminal pins connected to lead wires of the winding; and coupled stator yokes housing the coil bobbin therein and having a cutout for allowing the terminal block to protrude therethrough, the method comprising:
a process in which the two stator sub-assemblies are superimposed back-to-back such that respective coupled stator yokes of the two stator sub-assemblies are disposed in a predetermined relative position, with respective terminal blocks of the two stator sub-assemblies abutting on each other; and
a process in which the respective terminal blocks are positioned so as to be circumferentially overlapped with each other in a state of the respective coupled stator yokes being fixedly attached each other.
BRIEF DESCRIPTION OF THE DRAWINGS
These objects and other objects and advantages of the present invention will become more apparent upon reading of the following detailed description and the accompanying drawings in which:
FIG. 1 shows a cross-sectional structure of a stepping motor according to an embodiment of the present invention;
FIG. 2 shows a perspective view of a stator assembly shown in FIG. 1 ;
FIG. 3 shows an exploded view of a stator subassembly shown in FIG. 2 ;
FIG. 4 shows a partial illustration of a coupling state of an outer stator yoke and an inner stator yoke;
FIG. 5 shows a sectional view of the stator assembly shown in FIG. 2 taken along an abutting contact surface of the two stator subassemblies with the outer stator yoke housed in a coil bobbin:
FIGS. 6A-6D show four methods of positioning a terminal block;
FIG. 7 shows a side view of a stator assembly in a positioned state;
FIG. 8 shows an FPC;
FIG. 9 shows a perspective view of a conventional stator assembly;
FIG. 10 shows an exploded view of the stator subassembly shown in FIG. 9 ;
FIG. 11 shows a side view of the stator assembly shown in FIG. 9 ; and
FIG. 12 shows a configuration of a conventional FPC.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferred embodiments of the present invention will hereinafter be explained with reference to the accompanying drawings.
In the following preferred embodiments, a PM stepping motor using a permanent magnet and used as a rotating component or the like of an OA apparatus or an automobile will be discussed as an example.
FIG. 1 shows a cross-sectional structure of a stepping motor 1 generally comprising a stator assembly 12 and a rotor assembly 13 .
Referring to FIG. 2 , the stator assembly 12 is formed such that two stator subassemblies 14 and 14 are superimposed back to back. As shown in an exploded view of FIG. 3 , the stator subassembly 14 comprises an outer stator yoke 15 , an inner stator yoke 16 , a coil bobbin 17 and a cover ring 18 .
The outer stator yoke 15 constitutes a periphery and top surface of the stator subassembly 14 , and is made of a cup-shaped, cylindrical soft magnetic steel plate, and has a plurality of first pole teeth 15 a formed along its an inner circumference and bent up, and has a cutout 15 b formed in its outer circumferential wall. The first pole teeth 15 a are formed by bending the soft magnetic steel plate, and are set to be equidistant from one another at a predetermined electrical angle.
A cutout 15 b is formed in a side wall of the outer stator yoke 15 and is adapted to allow a terminal block 20 of a coil bobbin 17 to protrude therefrom. The terminal block 20 will be later described in detail. The outer stator yoke 15 also has a positioning notch 15 c.
The inner stator yoke 16 is made of a soft magnetic steel plate or the like and is a ring-shaped plate whose outer diameter is substantially equal to an inner diameter of the outer stator yoke 15 . The inner and outer stator yokes are arranged such that they are substantially concentric with each other, and the inner stator yoke 16 is accommodated in an open space of the outer stator yoke 15 in such a manner as to constitute a bottom surface of the stator subassembly 14 .
An inner circumference of the inner stator yoke 16 has the same diameter as that of the outer stator yoke 15 . A plurality of second pole teeth 16 a are formed on an inner circumferential side of the inner stator yoke 16 , by bending the soft magnetic steel plate, and are set to be equidistant one another at a predetermined electrical angle.
The first and second pole teeth 15 a and 16 a are intermeshed with a gap in a state that the outer and inner stator yokes 15 and 16 are properly positioned and coupled. FIG. 4 shows a partial illustration of that coupling state.
Referring back to FIG. 3 , a chamfered edge 16 b is formed, by cutting off a plano-convex portion from a ring-shaped circumferential portion of the inner stator yoke 16 . And, the chamfered edge 16 b has a substantially rectangular surface and it is close to a terminal block 20 of the coil bobbin 17 .
A positioning projection 16 c is formed at a point on the opposite to the chamfered edge 16 b on a circumferential side portion of the inner stator yoke 16 . The positioning projection 16 c is adapted to engage with a positioning notch 15 c of the outer stator yoke 15 , so that the outer and inner stator yokes 15 and 16 are positioned correctly and securely and coupled with each other.
The coil bobbin 17 is made of, for example, a plastic material and consists of a bobbin body 19 and the terminal block 20 .
The bobbin body 19 is substantially cylindrical with its cross-section in a shape of a letter H, and it has a magnet wire W wound therearound in many turns. The many turns of the magnet wire W wound around the bobbin body 19 make a coil.
The bobbin body 19 is disposed around the first and second pole teeth 15 a and 16 a such that it is concentric with the outer and inner stator yokes 15 and 16 .
The terminal block 20 is formed continuously from an inner flange in such a manner as to protrude outward with a predetermined width for predetermined length so as to be shaped substantially rectangular. The terminal block 20 protrudes, with a predetermined width, outwardly from the bobbin body 19 , and it is substantially rectangular. The terminal block 20 has a certain thickness for housing terminal pins in the axial direction of the bobbin body 19 . With the inner stator yoke 16 received in the coil bobbin 16 , the chamfered edge 16 b of the inner stator yoke 16 is shaped to fit an elevated portion of the terminal block 20 , thereby functioning as a means for positioning the terminal block 20 to slackly engage therewith.
As explained in detail later, the slack engagement means that the coil bobbin 17 and the inner stator yoke 16 can rotate stepwise to a certain extent in their circumferential direction,
A height of a lower elevation of the terminal block 20 is set to be substantially equal to a thickness of the inner stator yoke 16 . With the chamfered edge 16 b of the inner stator yoke 16 slackly engaging with the terminal block 20 , the terminal block 20 shares substantially the same plane (one surface of the stator subassembly 14 ) with the inner stator yoke 16 .
The terminal block 20 has an external sidewall substantially perpendicular to the axial direction of the bobbin body 19 and two terminal pins 21 and 21 each being a bar-like piece made of a conductive metal are fixed to the external sidewall of the in such a manner as to be erected substantially perpendicular to thereto.
Both ends of the magnet wire W wound around the bobbin body 19 , that is, lead-out wires each extend on a top major surface terminal block 20 , reach the terminal pins 21 and 21 , and are caught and soldered thereon.
The terminal pins 21 are adapted to be inserted into connection holes or the like in a PCB (printed circuit board) or an FPC (flexible printed circuit), so that electricity can be supplied to the magnet wire W via the terminal pins 21 , thus generating magnetic flux from the coil bobbin.
FIG. 5 shows a sectional view of the stator assembly shown in FIG. 2 taken along an abutting contact surface of the two stator subassemblies 14 and 14 with the outer stator yoke housed in a coil bobbin.
An angle φ made by two radii connecting a center of the outer stator yoke with two points on a minor arc of the terminal block to be housed in the cutout 15 b is set to be smaller than an angle θ of the cutout 15 b . For example, the angle θ is set at 44 degrees of mechanical angle and the angle φ 40 degrees of mechanical angle. Most favorably, the angle φ is set to be smaller than the angle θ by an electrical angle of 10 degrees or more.
As to the motor of the present invention, since a number of its magnetic poles is six, 360/6 degrees of mechanical angle is equivalent to 360 degrees of electrical angle. Therefore, since the most favorable angle φ depends on a number of magnetic poles of the concerned motor, it is preferable to use its electrical angle.
Consequently, by setting the angle φ of the terminal block 20 to be smaller than the angle θ of the cutout 15 b , a gap is generated between the terminal block 20 and inner walls of the cutout 15 b , with the terminal block 20 protruding from the cutout 15 b . Therefore, as the coil bobbin moves, the terminal block 20 can move at a predetermined angle, that is, an angle produced by the generated gap, in a circumferential direction of the coil bobbin 17 .
The terminal block 20 capable of rotating in the circumferential direction of the coil bobbin 17 eliminates a dislocation between the two terminal blocks 20 and 20 with the two stator yokes 15 and 16 superimposed at their respective predetermined positions in an assembly process of the stator assembly 12 , which will be mentioned in detail later.
Referring back to FIG. 3 , the cover ring 18 is made of an elastic material such as a plastic material which is a cylindrical material having its predetermined width and thickness. A diameter of the cover ring 18 is equal to or shorter than that of the coil bobbin 17 formed of wiring of the magnet wire W. The cover ring 18 has a slit 18 a at an end of its circumference, and the slit 18 a is adapted such that the cover ring 18 can easily cover the coil bobbin with the use of an elasticity thereof.
The width of the cover ring 18 is set to be the same as or a little shorter than a distance between inner sides of the two flanges of the coil bobbin. Consequently, the cover ring 18 press-fitted in the coil bobbin 17 is adapted to cover and protect wirings of a magnet wire W.
Referring back to FIGS. 1 and 2 , the stator assembly 12 in the stepping motor 11 is formed such that the two stator subassemblies 14 and 14 each with the above-described structure are superimposed back to back with their respective terminal blocks 20 and 20 adjacent to each other. The two stator subassemblies 14 and 14 are resin-molded with each other, which will be described in detail later.
Major surfaces not in contact with each other of the two superimposed stator subassemblies 14 and 14 are fixed, by projection welding or the like, to a first and second flanges 23 and 24 , which have been already formed each by punching out a stainless steel plate.
The rotor assembly 13 comprises a shaft 26 press-fitted in a metallic holder 25 , bearings 27 and 27 fixed by caulking or the like to the fist and second flanges 23 and 24 and rotatably holding the shaft 26 , and a magnet 28 disposed around an outer circumferential wall of the holder 25 . The magnet 28 is fixed by bonding or insertion molding such that it is concentric with the shaft 26 and is also concentric with and faces both the pole teeth 15 a and 16 a with a slight air gap. The magnet 28 is magnetized on its circumferential surface along the circumferential direction with a plurality of alternating N- and S-poles having a preset width. When a predetermined pulse driving voltage is applied on the windings in the stator assembly 12 , the first pole teeth 15 a are magnetized, for example, with S-pole. Consequently, N-poles in the surface of the magnet 28 are drawn toward the first pole teeth 15 a . In this manner, the rotor 13 moves by a predetermined angle.
How to assemble the stepping motor with the above-described structure will be hereinafter explained. The shaft 26 is forcibly inserted into the holder 25 , and the magnet 28 is fixed around the holder 25 , constituting the rotor assembly 13 .
The stator assembly 12 is structured as described below. The coil bobbin 17 is formed by winding a magnet wire W around the bobbin body 19 . A diameter, a number of turns, a length, etc. of the magnet wire W depend on applications of the stepping motor 11 . The cover ring 18 covers the coil bobbin 17 . The stator subassembly 14 is formed such that the inner and outer stator yokes 16 and 15 are coupled together in such a manner as to sandwich the coil bobbin 17 covered by the cover ring 18 . Here, the terminal block 20 of the coil bobbin 17 , the cutout 15 b of the outer stator yoke 15 and the chamfered edge 16 b are disposed in such a manner as to mate with one another.
Then, using a predetermined holding jig, the two stator subassemblies 14 and 14 are correctly positioned such that their respective inner stator yokes 16 and 16 abut back to back. Alternatively, the holding jig may be used so as to directly hold each component of the two stator subassemblies 14 and 14 in their respective assembly sequence.
The two stator subassemblies 14 and 14 are superimposed such that the pole teeth of their respective stator yokes 15 and 16 are misaligned, each having an optimum difference in an electrical angle, for example, of 90 degrees.
With the above-described structure of the two stator subassemblies 14 and 14 , their respective terminal blocks 20 and 20 have to be fittingly positioned with respect to one another. For example, there are several mechanisms for achieving the fitting positioning of the coil blocks 20 and 20 as shown in FIGS. 6A-6D .
FIG. 6A shows a first mechanism in that positioning through-holes 20 a and 20 a for each of the terminal blocks 20 and 20 are bored therein in a direction substantially perpendicular to main surfaces thereof (an axial direction of the cylindrical coil bobbin 17 ). The positioning is carried out by inserting one positioning pin 30 into both the positioning through-holes 20 a and 20 a.
FIG. 6B shows a second mechanism in that positioning grooves 20 b and 20 b are cut in opposing surfaces of the two terminal blocks 20 and 20 in their protruding direction, placing the positioning grooves 20 b and 20 b at substantially a center of each coil block. The positioning is carried out by placing the one positioning pin 30 along both the positioning grooves with the two stator subassemblies 14 and 14 superimposed back to back.
When using the positioning mechanisms shown in FIGS. 6A and 6B , the positioning pin 30 is removed after, for example, the terminal pins 21 have been connected to a circuit board such as an FPC, which will be explained later in detail.
FIG. 6C shows a third mechanism in that either a V-shaped protuberance 20 c or a V-shaped groove 20 d in cross-section to mate with one another is formed on an opposing surface of each of the terminal blocks 20 and 20 . The positioning is carried out by mating the protuberance 20 c with the groove 20 d.
FIG. 6D shows a fourth mechanism in that a positioning jig is used for fittingly positioning the terminal blocks 20 and 20 by aligning sidewalls on the same side of the terminal blocks 20 and 20 .
FIG. 7 shows a side view of the two stator subassemblies 14 and 14 properly positioned using any one of the above-described four positioning mechanisms. Even if a displacement in relative angle between the notches 15 b and 15 b of the stator subassemblies 14 and 14 occurs, any one of the four positioning mechanisms can serve to eliminate the displacement in relative angle.
After that, with the outer and inner stator yokes 15 and 16 and the terminal block 20 properly positioned, the two stator subassemblies 14 and 14 are resin-molded integrally with one another to thereby form the stator assembly 12 .
Then, the second flange 24 having one bearing 27 fixed, by welding or the like, thereto is fixed to one main surface of the stator assembly 12 . And, the rotor assembly 13 is housed in an inner surface of the ring-shaped stator assembly 12 such that one end of the shaft 26 extends through the bearings 27 and 27 . And, the first flange 23 having the other bearing 27 fixed thereto is disposed such that the other end of the shaft 26 extends through the one bearing 27 , and then the other main surface of the stator assembly 12 is fixed, by welding or the like, to the first flange 23 , thereby to complete the stepping motor 11 in this embodiment.
The stepping motor 11 assembled by the above-described method is to be mounted on an apparatus such as a measuring instrument. An electrical connection between the stepping motor 11 and an apparatus on which it is mounted is made via a circuit board, for example, an FPC (flexible printed circuit) 32 having four connection holes 33 as shown in FIG. 8 . Alternatively, the stepping motor 11 may be connected to a rigid circuit board not having flexibility, unlike the FPC 32 .
Four terminal pins 21 projected on the two terminal blocks 20 and 20 are each inserted into the four connection holes 33 in the FPC and soldered therein. As described above, after the outer and inner stator yokes 15 and 15 are positioned relative to one another, the two terminal blocks 20 and 20 are again correctly positioned through adjustment to thereby eliminate their relative dislocation.
Therefore, it is not necessary to do any additional thing such as setting a diameter of each of the connection holes 33 to be relatively long so as to eliminate the dislocation of the terminal pins 21 . Consequently, the above-described mechanisms do not involve any difficulty or complication such as inability of smooth soldering between the connection holes 33 and the terminal pins 21 due to the long diameter of each of the connection holes 33 , thereby achieving an easy and highly-reliable electrical connection.
In brief, in this embodiment, the terminal block 20 can rotate by a predetermined angle as the bobbin 17 moves together with the terminal block projecting from the cutout 15 b.
Consequently, this embodiment can eliminate the dislocation between the two terminal blocks 20 and 20 and 20 with the outer stator yokes 15 and 16 fixed at a predetermined relative location in a process of assembling the stator assembly 12 .
Therefore, for example, it becomes easier to solder the terminal pins 21 to the FPC 32 , achieving a highly-reliable and stable electrical connection between the stepping motor and the apparatus on which it is mounted.
The present invention is not limited to the above-described embodiment, and alternatively there may be any other variations and applications.
In the above-described embodiment, the terminal block 20 projects in such a manner as to project with a predetermined width in a direction substantially perpendicular to an axial direction of the bobbin 17 . However, a shape of the terminal block 20 is not limited to the above-described example, and alternatively it may be any shape as long as it is possible to connect a magnet wire to the terminal pins 21 , which in turn is connected to an external electrode. For example, it may be structured such that a width of a potion horizontally overlapping the outer stator yoke 15 is narrower than the width of the other portion (the protruding portion).
In the above-described embodiment, the PM stepping motor is used as an example for explanation. However, the present invention can also be applied to the other stepping motors and any other motor using a bobbin having a magnet wire wound therearound, such as spindle motors and servo motors.
Various embodiments and changes may be made thereunto without departing from the broad spirit and scope of the invention. The above-described embodiments are intended to illustrate the present invention, not to limit the scope of the present invention. The scope of the present invention is shown by the attached claims rather than the embodiments. Various modifications made within the meaning of an equivalent of the claims of the invention and within the claims are to be regarded to be in the scope of the present invention
This application is based on Japanese Patent Application No. 2002-257199 filed on Sep. 2, 2002 and Japanese Patent Application No. 2003-118825 filed on Apr. 23, 2003, and including specification, claims, drawings and summary. The disclosure of the above Japanese Patent Application is incorporated herein by reference in its entirety. | A stator sub-assembly comprises: a coil bobbin which is composed of a cylinder having a winding of a magnet wire therearound, and a terminal block provided with terminal pins connected to lead wires of the winding and coupled stator yokes housing said coil bobbin therein and having a cutout for allowing the terminal block to protrude therethrough. The cutout has a width adapted to allow the terminal block to circumferentially shift rotationally about the center of an axial direction of the coil bobbin. | 7 |
FIELD OF THE INVENTION
[0001] The present invention relates to a method for reducing the excess sludge generated in the biological treatment of various types of organic waste fluid, and an apparatus for reducing excess sludge using this method.
BACKGROUND OF THE INVENTION
[0002] The organic waste fluid which is discarded in the form of various types of industrial waste fluids as well as domestic sewage is primarily treated by biological methods such as by using activated sludge. Since the microbes used can proliferate in abundance during this process, creating massive amounts of excess sludge whose disposal can present a problem. As methods for handling this type of excess sludge, it has been used for improving soil or as compost, but no fundamental solution has yet been reached, so that in most cases, the excess sludge is dehydrated and incinerated or buried as industrial waste.
[0003] However, in recent years, such incineration has come to be seen as possibly posing a threat by generating toxic substances including environmental hormones such as dioxins, and burial ultimately also gives rise to similar problems in the form of toxic substances which can leak out over time. Therefore, there has been a call for development of techniques for reducing the excess sludge itself to provide a more fundamental solution to the problem, and many proposals have been offered.
[0004] Among these, the methods of Japanese Patent No. 2806495, Japanese Patent Application, First Publication No. H11-128975 and Japanese Patent Application No. H11-218022 are relatively inexpensive and easy to control. All of these methods involve the addition of alkalis to the excess sludge followed by exposure to ultrasonic waves.
[0005] However, the method of Japanese Patent Application, First Publication No. H11-128975 is performed at a pH of 10.5 or less in consideration of the cost of neutralization that is required when returning the solubilized excess sludge to the biological treatment, so that the expected solubilization effect is difficult to achieve with this method.
[0006] The method of Japanese Patent Application No. H11-218022 enables the pH to be raised to 12-13 by improving on the neutralization procedure, thus improving the solubilization effect, but a lot of time is still required for the ultrasonic treatment, which requires high output and is therefore very expensive. Additionally, the ability of microbes to be used for decomposition leaves something to be desired, to the point of being difficult to put into actual practice. In connection with the art described above, there has been a strong demand for technological improvements that would allow for cost reductions and improved effectiveness by obtaining the desired level of solubilization effects, and particularly the ability of microbes to be used for decomposition, even with a low ultrasonic output and a short time of application thereof.
SUMMARY OF THE INVENTION
[0007] The present invention has the object of offering a method and apparatus for solubilizing excess sludge, with a higher capacity for solubilization than conventional methods, having a low overall cost and allowing equipment to be made smaller.
[0008] A method for reducing excess sludge according to claim 1 of the present invention is characterized by adding a solubilizing agent to excess sludge generated by a microbial treatment of organic sewage; applying ultrasonic waves; applying a reduced pressure swelling treatment; and returning the result to the microbial treatment, thereby reducing the volume of said excess sludge.
[0009] Due to this method, a high level of solubilization can be obtained by the reduced pressure swelling process, thus resulting in a particularly high level of reusability by microbes, and achieving a high rate of reduction.
[0010] Another method for reducing excess sludge according to the present invention is characterized in that said solubilizing agent is an alkali, a bacteriolytic agent, or a combination thereof.
[0011] According to this method, the alkalis contribute to the dissolution of proteins, are not harmful to the environment if neutralized, and further in biological treatment systems, and can be used to adjust the pH prevent reductions in pH due to dissolution of carbon dioxide gas. While possible alkalis include, for example, NaOH, KOH, Mg(OH) 2 and Ca(OH) 2 , other compounds may be used as long as they are capable of raising the pH.
[0012] Additionally, the bacteriolytic agent has the function of destroying the cell walls of microbes. While there are many types of bacteriolytic agents, the type does not matter as long as it is capable of decomposing bacteria. Examples include hydrogen peroxide, dichlorous soda and ozone.
[0013] An apparatus for reducing excess sludge according to another embodiment of the present invention is characterized by comprising means for adding a solubilizing agent to excess sludge generated by microbial treatment of organic sewage; ultrasonic wave applying means for applying ultrasonic waves; and reduced pressure swelling means, provided downstream of the ultrasonic wave applying means, for applying a reduced pressure swelling process to the excess sludge.
[0014] According to this embodiment, a high rate of solubilization is achieved by the reduced pressure swelling means, thus resulting in a particularly high level of reusability by microbes, and achieving a high rate of reduction.
[0015] An apparatus for reducing excess sludge according to another embodiment of the present invention is characterized in that the reduced pressure swelling means is a homogenizer.
[0016] According to this embodiment, solubilizing agents such as alkalis and ultrasound are used to destroy or damage the cell walls of microbes, and a reduced pressure swelling process causes the contents of the cells to leak out, after which further reactions by solubilizing agents causes them to be converted to substances which can be handled by microbes. Whereas the solubilization effect due to the reduced pressure swelling can be raised by raising the pressure of the homogenizer, the optimum operating conditions may be determined in consideration of the manufacturing cost and running cost of the apparatus.
[0017] An apparatus for reducing excess sludge according to another embodiment of the present invention is characterized in that said ultrasonic wave applying means and said reduced pressure swelling means are constructed as separate parts, the ultrasonic wave applying means and reduced pressure swelling means being serially connected directly or through the medium of other equipment.
[0018] According to this embodiment, the ultrasonic wave applying means and the reduced pressure swelling means are separate parts, thus allowing for a design which maximizes the performance of the respective parts. Furthermore, the operating conditions of the processes of application of ultrasonic waves and reduced pressure swelling can be freely controlled independently for respective optimization.
[0019] An apparatus for reducing excess sludge according to yet another embodiment of the present invention is constructed as a single apparatus having the functions of both said ultrasonic wave applying means and said reduced pressure swelling means.
[0020] According to this embodiment, the ultrasonic wave applying means and reduced pressure swelling means are constructed as a single apparatus, thus allowing for a design capable of holding the size of the apparatus to a minimum. Additionally, the cost of the apparatus overall can be reduced, thus enabling the apparatus to be easily controlled as well.
[0021] An apparatus for reducing excess sludge according to yet another embodiment of the present invention is characterized in that the ultrasonic wave applying means includes an ultrasonic vibrator, and said reduced pressure swelling means comprises a plate having a plurality of through holes formed therein, provided at a position downstream of said ultrasonic vibrator such as to intersect flow.
[0022] According to this embodiment, the plate (porous plate) positioned against the flow gives rise to the reduced pressure swelling effect, thereby ensuring a high level of solubilization.
[0023] An apparatus for reducing excess sludge according to yet another embodiment of the present invention is characterized in that a flow-receiving plate is provided between said ultrasonic wave applying means and said reduced pressure swelling means so as to obstruct flow.
[0024] According to this embodiment, the flow-receiving plate that is provided on the flow path increases the ultrasonic wave cavitation effect, changes the flow of the solution, and aids in mixture, so that a high rate of solubilization can be obtained even if the plate (porous plate) is given a larger hole diameter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] [0025]FIG. 1 is diagram showing a method for reducing excess sludge according to an embodiment of the present invention.
[0026] [0026]FIG. 2 is a schematic diagram showing an excess sludge reducing apparatus according to an embodiment of the present invention.
[0027] [0027]FIG. 3 is a schematic diagram showing an excess sludge reducing apparatus according to an embodiment of the present invention.
[0028] [0028]FIG. 4 is a schematic diagram showing an excess sludge reducing apparatus according to an embodiment of the present invention.
[0029] [0029]FIG. 5 is a schematic diagram showing an excess sludge reducing apparatus according to an embodiment of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0030] Herebelow, embodiments of the present invention shall be described with reference to the drawings.
[0031] [0031]FIG. 1 shows a flow chart of an example of a sewage treatment method including the excess sludge reducing method according to an embodiment of the present invention. In FIG. 1, raw fluid 1 which is basically organic sewage is passed through an initial precipitation pool 2 and a flow regulating pool 3 , then flows through a biological treatment tank 4 where it is treated by microbes, after which it is separated into solid and liquid parts in a final precipitation pool 5 to form treated water 6 and sludge (return sludge 7 and excess sludge 8 ). A portion of this sludge is returned to the biological treatment tank as return sludge 7 , while the rest is taken as excess sludge, which may or may not be passed through a sludge concentrating tank 10 , and is directed to a sludge solubilizing process DV 11 where the excess sludge 8 is solubilized and broken down. The solubilized sludge 9 is returned to the flow regulating tank 3 or biological treatment tank 4 or both in the sewage treatment process, and the solubilized sludge 9 is then broken down by microbes in the biological treatment tank 4 .
[0032] The excess sludge 8 which is introduced into the sludge solubilizing process DV 11 is processed with an ultrasonic vibrator, and also undergoes a reduced pressure swelling process by a homogenizer for the solubilization treatment.
[0033] The sludge solubilization process DV 11 has the functions of both ultrasonic wave applying means and reduced pressure swelling means in the form of the homogenizer. This structure is shown in FIGS. 2 - 5 .
[0034] [0034]FIGS. 2 and 3 show embodiments in which the ultrasonic wave applying means and the reduced pressure swelling means (homogenizer) are separated and connected serially. In the drawing, 12 denotes an ultrasonic vibrator as a part of the ultrasonic wave applying means, 13 denotes an ultrasonic treatment tank, 14 denotes a pump, 15 denotes a reduced pressure swelling treatment tank, and 16 denotes a homogenizer used as reduced pressure swelling means.
[0035] [0035]FIGS. 4 and 5 show a single apparatus having the functions of both ultrasonic wave applying means and reduced pressure swelling means (homogenizer). Those wherein these means are manufactured as separate parts, then assembled together by means of fastening means such as bolts and nuts shall be considered to be included among the single apparatus mentioned above.
[0036] [0036]FIG. 4 shows an embodiment wherein a porous plate 26 is placed immediately before the ultrasonic vibrator 22 in the direction of application of the ultrasonic waves, so that the excess sludge which has been exposed to the ultrasonic waves is sent to the porous plate 26 due to the propagation of the ultrasonic waves and the pressure from the pump.
[0037] Due to the employment of this structure, the pressure on the primary side of the porous plate 26 is high, but the pressure on the secondary side of the porous plate 26 is close to atmospheric pressure, so that the liquid which has passed through the porous plate 26 immediately lowers to a pressure close to atmospheric pressure. This pressure difference causes the microbes in the excess sludge to swell due to the sudden pressure drop, so that the bacteria which have undergone cavitation under the microscopic high frequency waves of the ultrasonic vibrations then undergo a swelling effect of the liquid itself, the destruction of the cell walls causing leakage of the content of the cells under further swelling effects, and finally being treated by solvents such as alkalis to form substances that are easily broken down by microbes. Additionally, the cell walls which have been damaged by the action of the alkali solvent and ultrasonic waves are completely destroyed by the reduced pressure swelling, thus promoting the leakage of the fluids contained therein.
[0038] [0038]FIG. 5 shows an embodiment in which a flow-receiving plate 27 is placed immediately before the ultrasonic vibrator 22 .
[0039] By employing this structure, the solution which has been treated by the ultrasonic waves is kept at a high pressure by the flow receiving plate 27 , passes through the passages to the sides of the flow-receiving plate 27 , is relieved of the pressure at the exits to the cell (porous plate 26 ), and there undergoes swelling so as to destroy the cell walls and promote leakage of their content.
[0040] The exit of the cell may be a porous plate, a showerhead type plate or a single circular hole. Of these, the showerhead type plate and single circular hole are not easily clogged, so that even if insoluble matter other than microbes are mixed therein, there is no need for a foreign matter removing step preceding this treatment, and the operation can be performed stably. When considering overall factors such as clogs and the reduced pressure swelling effect, it is desirable to use a showerhead plate.
[0041] Additionally, the above-mentioned flow-receiving plate 27 may be flat or of arcuate shape. While it is desirable to provide a flow-receiving plate 27 , under special circumstances, a certain degree of effectiveness can be achieved without providing a flow-receiving plate 27 .
[0042] In this way, with the method and apparatus for reducing excess sludge according to the present invention, the solubilization effect is raised by applying ultrasonic waves under alkaline conditions, then applying a homogenizer, or applying these processes simultaneously. That is, the synergistic effects of the ultrasonic waves and homogenizer are able to raise the solubilization effect of the microbial cells. Here, the homogenizer is an apparatus which passes the subject material through a porous plate under pressurized conditions and instantly depressurizes the material, thereby destroying the cells of microbes and causing the content of the cells to leak out.
[0043] The process of destroying or damaging the cell walls of microbes with the application of alkalis and ultrasonic waves, causing the content of the cells to leak outside the cells and converting them to substances which can be handled by microbes is important. In order to perform this step, the pressure of a partially solubilized liquid is raised and instantly depressurized, causing the cells to swell, so that the contents of cells with damaged or destroyed cell walls will spill out of the cells, to be acted on by the alkalis to change into substances that are readily decomposed by microbes.
[0044] In some cases, the viscosity of the excess sludge can be raised by the action of the alkalis and ultrasonic waves, thereby increasing the resistance to microscopic movements of substances in the liquid, thereby lowering the susceptibility of the partially solubilized cells and liquid itself (alkali liquid) to mixture, making solubilization by further decomposition difficult so that the solubilization effects cannot be improved. In order to overcome this problem, the homogenizer is used to obtain a synergistic effect. While alkalis have been used above, similar effects can be obtained using other types of bacteriolytic agents.
[0045] Additionally, the solubilized sludge can then be returned to the former stages of the biological treatment process, to be broken down by other microbes to reduce the excess sludge.
[0046] Herebelow, the method and apparatus for reducing excess sludge according to the present invention shall be described in detail with reference to examples.
EXAMPLE 1
[0047] Solubilization tests were performed on sludge (from a food processing factory) obtained during treatment of organic sewage with aerobic microbes under the following conditions.
Sludge Concentration; 10050 mg/liter, pH 6.3 pH Adjuster: NaOH Initial Solubilization pH: 12 Ultrasonic Frequency: 19 Hz, Output 400 W, Retention Time 1 min (using equipment produced by Seidensha Electronics Co., Ltd.)
[0048] As an indicator of solubilization, the sludge was separated in a centrifuge (10 min at 4000 rpm), and judged on the basis of measurements of the increase in COD concentration in the sludge using the recovered fluid in measurements of the oxygen consumption rate by potassium dichromate (COD cr ) at 150° C. (in accordance with the JIS K0102 standard). This measurement was made using a colorimeter and COD reactor manufactured by HACH Corporation.
TABLE 1 A B C D E F COD 255 1880 5205 6560 6860 6425 (mg/l)
[0049] A: Only homogenizer
[0050] B: Alkali homogenizer.
[0051] C: Alkali ultrasound.
[0052] D: Alkali ultrasound+serially connected homogenizer (FIG. 3).
[0053] E: Alkali ultrasound+integral porous-plate homogenizer (FIG. 4).
[0054] F: Alkali ultrasound+integral showerhead homogenizer (FIG. 5).
[0055] Table 1 shows the results of solubilization using the excess sludge from a food processing factory. The homogenizers of the structures shown in FIGS. 3, 4 and 5 were respectively used. The porous plates of FIGS. 3 and 4 had pores with a diameters of 1.5 mm, with a porosity of 38%, with the showerhead plate of FIG. 5 having six holes with a diameter of 4.5 mm each. For the purposes of comparison, the results for the cases where no homogenizer is used, where only the homogenizer is used and only alkalis are used are also shown. The pressure of the pump sending liquid to the homogenizers was 4.0-6.0 kgf/cm 2 .
[0056] As can be seen in Table 1, the solubilization effects improved dramatically when using a homogenizer as opposed to cases in which a homogenizer was not used. Additionally, it can be seen that the solubilization effects are not as significant when using only a homogenizer. While the showerhead type plate gave poorer results than the porous plate, it still demonstrated a marked improvement over the case where only ultrasonic waves are used. Additionally, the fact that the integral type apparatus gave better results than the separate serial type is notable. This is believed to be due to the presence of resistance against direct flow. In any case, Table 1 serves to demonstrate that the COD changes in sludge which has undergone a reduced pressure swelling effect in a homogenizer.
EXAMPLE 2
[0057] A biological treatment experiment was performed to turn the sewage from the same food processing factory into water in accordance with the flow chart of FIG. 1. The experiment was performed by sending fluid which had been solubilized by ultrasonic waves and a homogenizer at room temperature and alkaline conditions (initially ph 12) to a fluid rate regulating tank without adjusting the pH, and observing the effects of the biological treatment. The results are shown in Table 2.
[0058] The testing conditions were as follows:
Water Flow Rate: 50 liters/day Water BOD: 1050 mg/liter Water Flow Regulating Tank: 50 liter Amount of Sludge to Solubilization: 3.2 times amount of excess sludge Solubilizing Agent: NaOH Ultrasound Exposure Time: 1 minute
[0059] [0059] TABLE 2 O A B C D E F Quality of Treated Water BOD (mg/l) 7.5 7.5 7.2 7.3 7.3 7.6 7.4 COD (mg/l) 7.5 8 10 12 14 14.2 14.1 SS (mg/l) 11 11 11.5 11.4 11.3 11.2 11.3 pH 7.2 7.2 7.3 7.3 7.3 7.3 7.3 BOD Sludge 0.44 0.42 0.31 0.14 0.04 0.02 0.02 Conversion Rate (g-SS/g-BOD)
[0060] O represents an experiment made using a test apparatus without the solubilization step in the flow chart of FIG. 1, while the others are the same as their counterparts in Table 1.
[0061] As shown in Table 2, the results for the case of solubilization with only a homogenizer in the pressure range of 4.0-6.0 kgf/cm 2 are almost the same as those for the case where there is no solubilization step, and this is clearly due to the fact that there is no sludge reducing effect. While significant solubilization effects did appear in the case of the alkali homogenizer, the expected level of effects were not obtained. While there was a considerable reducing effect with alkali ultrasound, the BOD sludge conversion rate was still only 0.14. On the other hand, when applying ultrasonic waves under alkali conditions, then applying the homogenizer, in all cases the sludge generation rate was much lower than in the case of alkali ultrasound, and there was almost no difference in the treated water quality.
[0062] Upon comparison of the results of the respective experiments shown in Table 2 with Table 1, when taking the COD as the solubilization indicator for evaluating the solubilization, there is a solubilization effect in the case of a homogenizer with alkali ultrasound, but when taking the rate of conversion of the sludge as the indicator for evaluating the sludge reduction rate, the effect of the homogenizer is shown to be considerably large. This is believed to be due to the fact that the homogenizer promotes leakage of the content from the cell walls of microbes, thus assisting in biological treatments by further decomposition. From these results, the synergistic effect of alkali ultrasound and the homogenizer was confirmed to have a major impact on the sludge reduction effect.
[0063] As explained above, according to the method for reducing excess sludge according to the present invention, the solubilization effect can be raised by applying ultrasound under alkaline conditions, then applying a reduced pressure swelling process in a homogenizer, or applying these processes simultaneously. That is, by synergizing the action of the ultrasound with the action of the homogenizer, the effect of solubilization of microbial cells can be increased.
[0064] According to a method for reducing excess sludge based on another embodiment of the present invention, the alkalis contribute to the dissolution of proteins, are not harmful to the environment if neutralized, and further in biological treatment systems, and can be used to adjust the pH prevent reductions in pH due to dissolution of carbon dioxide gas.
[0065] According to an apparatus for reducing excess sludge based on another embodiment of the present invention, a high solubilization rate is ensured by reduced pressure swelling means, and the resulting high solubilization effect enables a high rate of reduction to be attained.
[0066] According to an apparatus for reducing excess sludge based on another embodiment of the present invention, solubilizing agents such as alkalis and ultrasound are used to destroy or damage the cell walls of microbes, and a reduced pressure swelling process causes the contents of the cells to leak out, after which further reactions by solubilizing agents causes them to be converted to substances which can be handled by microbes.
[0067] According to an excess sludge reducing apparatus based on another embodiment of the present invention, ultrasonic wave applying means and reduced pressure swelling means are separate apparatus, so that they can be designed for maximum performance of the respective apparatus, and the operating conditions of the ultrasonic wave application and reduced pressure swelling processes can be independently controlled for optimum results.
[0068] According to an excess sludge reducing apparatus based on another embodiment of the present invention, ultrasonic wave applying means and reduced pressure swelling means are provided in a single apparatus, so that the size of the apparatus can be designed to be made as compact as possible, thereby reducing the cost of the apparatus overall, and enabling the apparatus to be easily controlled.
[0069] According to an excess sludge reducing apparatus based on another embodiment of the present invention, a high solubilization rate is obtained by a plate placed to obstruct the flow.
[0070] According to an excess sludge reducing apparatus based on yet another embodiment of the present invention, a high solubilization rate is obtained by a flow receiving plate which is provided on the flow path. | The invention offers a method and apparatus for solubilizing excess sludge, having a high solubilizing ability, a low total cost, and capable of reducing the size of facilities. The method for reducing excess sludge comprises adding a solubilizing agent to excess sludge generated by microbial treatment of organic sewage, applying ultrasonic waves, applying a reduced pressure swelling step, then returning the result to the microbial treatment, whereby the volume of the excess sludge can be reduced. The apparatus for reducing excess sludge comprises means for adding a solubilizing agent to excess sludge generated by applying a microbial treatment to organic sewage, ultrasonic wave applying means for applying ultrasonic waves, and reduced pressure swelling means provided downstream of the ultrasonic wave applying means for applying a reduced pressure swelling process to the excess sludge. | 2 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/897,972, filed Oct. 31, 2013, and entitled “Foldable Frame for Transporting Fishing Equipment,” the entire contents of which are incorporated herein by reference.
FIELD OF THE DISCLOSURE
[0002] The present disclosure relates to foldable frame devices and more particularly foldable frame devices for transporting fishing equipment and assorted items.
BACKGROUND
[0003] The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
[0004] Many people of all ages enjoy the activity of fishing. Fishing can take place in various locations such as the beach, lake, river, wharf, dock, jetty, bridge, land outcropping, or the like. In order to participate in the activity of fishing, one must transport the necessary fishing equipment such as buckets, bait, hooks, lines, nets, rods, reels, tackle boxes and the like, to the fishing site. Fishing equipment may be carried by hand or transported by a fishing back pack.
[0005] An existing fishing back pack discloses a carrier, rod holders and sand spikes. The carrier may have one or more pockets and one or more removable bags. The pockets and removable bags may be used to carry fishing equipment, a built in cutting board and the like. The carrier may be transported by way of a harness. The carrier may be placed in a stationary position by way of the sand spikes. Rod holders may be configured on either side of the carrier.
[0006] The fishing back pack described above allows for transportation of only two fishing rods and reels. The many pockets and removable bags make it difficult to locate items, as well as hampering the size of gear which can be transported. It is also difficult to clean. One may also inadvertently leave behind necessary fishing tackle following the removal of one of the bags. The current fishing back pack cannot be modified to form a flat surface area to hold items such as a fishing bucket. To further complicate matters, the current fishing backpack is bulky and cannot be folded for storage in compact spaces.
[0007] Given the foregoing, what is needed is a foldable frame device capable of transporting fishing tackle by an individual. Additionally, foldable frame devices are desired which may be used as multifunctional tables and which are capable of being folded during transportation or storage in small spaces.
SUMMARY
[0008] 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 subject matter, nor is it intended to be used to limit the scope of the subject matter.
[0009] This disclosure addresses the above-described needs by providing folding frame devices configured to transport assorted items. Assorted items include, but are not limited to, fishing tackle.
[0010] Aspects of the present disclosure provide a device configured to facilitate the transportation of assorted items such as fishing tackle and provide for a multifunctional surface area, without taking up significant storage space. Devices configured in accordance with an aspect of the present disclosure are foldable, compact frames that can be carried on the back of a user or can be removably placed on a surface, such as a jetty, a beach, or a bank. Such foldable frame devices can also be folded into compact form during transportation and storage. Products according to the present disclosure are ideal for users who desire to carry fishing tackle to engage in fishing. They may also eliminate the need to transport a separate flat surface area such as a table, thereby decreasing the load that must be carried by the user.
[0011] In an aspect, a foldable frame device is configured to increase the amount of items that can be transported by a user during fishing and to conserve space when being stored. Such a foldable frame also renders transporting items easier, especially over difficult terrain such as a trail, sand dunes, or a jetty. Two straps are secured over the shoulders of a user to support the weight of the foldable frame and any objects placed on the foldable frame. The straps are secured at the top of the foldable frame and a rotatable leg is moveably attached to the bottom of the foldable frame. When in use, the leg is placed in an extended position by rotating the leg into a position approximately perpendicular to the body of the frame. Objects to be transported during fishing are placed on the extended leg for transportation. Such configuration allows for transportation of larger items such as buckets. Additionally, such configuration may also function as a large surface area similar to a table for cutting fish, holding fish, baiting hooks and the like. In some aspects, when the device is in use, it is configured to be folded for transportation of slim items such as rods and reels. This configuration may also allow for the foldable frame to be placed onto a surface such as sands, rocks, grass or the like. In an aspect, the foldable frame may further comprise deployable support poles. The deployable support poles may be extended from the foldable frame and support the foldable frame when placed on the ground. When the device is not in use, it is configured to be folded for storage in compact spaces.
[0012] Further features and advantages of the systems and apparatus disclosed herein, as well as the structure and operation of various aspects of the present disclosure, are described in detail below with reference to the accompanying figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The features and advantages of the present disclosure will become more apparent from the Detailed Description set forth below when taken in conjunction with the drawings in which like reference numbers indicate identical or functionally similar elements.
[0014] FIG. 1 is a side view of a foldable frame device being used, in accordance with an aspect of the present disclosure.
[0015] FIG. 2 is a front view of a foldable frame device wherein the device leg is extended, in accordance with an aspect of the present disclosure.
[0016] FIGS. 3A and 3B are three quarter views of a foldable frame device wherein the device leg is extended, in accordance with an aspect of the present disclosure.
[0017] FIG. 4 is a front view of a foldable frame device wherein the device leg is in the folded position, in accordance with an aspect of the present disclosure.
[0018] FIG. 5 is a side view of a foldable frame device wherein the device leg is in the folded position, in accordance with an aspect of the present disclosure.
[0019] FIG. 6 is a rear perspective view of a foldable frame device wherein the device leg is in the folded position, in accordance with an aspect of the present disclosure.
[0020] FIG. 7 is a side view of a foldable frame device being worn by a user, in accordance with an aspect of the present disclosure.
[0021] FIG. 8 is a rear view of a foldable frame device, in accordance with an aspect of the present disclosure.
[0022] FIG. 9 is a perspective view of a second embodiment of a foldable frame device being used, in accordance with an aspect of the present disclosure.
[0023] FIG. 10 is a three quarter view of a foldable frame device wherein the device leg is extended, in accordance with an aspect of the present disclosure.
[0024] FIG. 11 is a front view of a foldable frame device wherein the device leg is extended, in accordance with an aspect of the present disclosure.
[0025] FIG. 12 is a side perspective view of a foldable frame device wherein the device leg is extended, in accordance with an aspect of the present disclosure.
[0026] FIG. 13 is a rear perspective view of a foldable frame device wherein the device leg is extended, in accordance with an aspect of the present disclosure.
[0027] FIG. 14 is a rear view of a foldable frame device wherein the device leg is extended, in accordance with an aspect of the present disclosure.
[0028] FIG. 15 is a side view of a foldable frame device wherein the device leg is extended, in accordance with an aspect of the present disclosure.
[0029] FIG. 16 is a front view of a foldable frame device wherein the device leg is in the folded position, in accordance with an aspect of the present disclosure.
[0030] FIG. 17 is a three quarter view of a foldable frame device being used atop a paddleboard, in accordance with an aspect of the present disclosure.
[0031] FIG. 18 is a rear view of a foldable frame device being worn by a user, in accordance with an aspect of the present disclosure.
DETAILED DESCRIPTION
[0032] The present disclosure is directed to devices and attachments which allow for transporting assorted items. Assorted items include, but are not limited to, fishing equipment (e.g. fishing rods and reels, tackle boxes, buckets and the like). Such devices may enable easier transportation of fishing equipment, increased carrying capacity and provide for a flat surface and/or an elevated surface suitable for multifunction use.
[0033] In an aspect, a foldable frame device comprises a body, a base and a leg. The foldable frame device is configured to hang from two straps removably wearable on the back of a user, similar to a harness. The body connects to the base. The base is rotatably connected to the leg. The leg rotates from a stored, vertical position to an in use, horizontal position which is perpendicular to the body. Assorted items may be placed on the extended leg to provide the user with a flat multifunctional surface.
[0034] In some aspects, the foldable frame device is configured to be folded into condensed form for transportation. In condensed form, the leg is rotated vertically and significantly in parallel with the folding device body. In such aspects, the user may choose to carry or store slender items such as rods and reels.
[0035] In some aspects, when the foldable frame is not in use, it is configured to be folded into condensed form for storage. The leg is rotated into the storage position significantly in parallel with the folding device body.
[0036] Unless otherwise noted, for the purposes of the present disclosure, “user” and its plural forms refer to adults and children which may participate in fishing or otherwise utilize foldable frame devices of the present disclosure.
[0037] Referring to FIG. 1 , a side view of a foldable frame device 100 being used, in accordance with an aspect of the present disclosure, is shown.
[0038] Foldable frame device 100 comprises a body 102 , a base 104 and a leg 106 . Body 102 is a rigid support structure configured to position foldable frame device 100 on the back of a user 120 as shown in FIG. 7 and support the weight of assorted items placed thereon (e.g., during transportation). Body 102 may be constructed of one or more sturdy materials such as plastic, aluminum or the like. In some aspects, the material chosen for body 102 may be configured to be lightweight, enabling folding frame device 100 to be easily picked up and carried each time it is used to transport assorted items.
[0039] Referring now to FIG. 2 , a front view of foldable frame device 100 wherein leg 106 is extended, in accordance with an aspect of the present disclosure, is shown.
[0040] In an aspect, body 102 comprises one or more cross members 108 (labeled, for clarity, only as cross members 108 a - b in FIG. 2 ) and one or more vertical members 110 (labeled, for clarity, only as vertical members 110 a - b in FIG. 2 ). The back of body 102 may be a flat surface as shown in FIG. 6 , configured to contact the back of user 120 as shown in FIG. 7 . Vertical member 110 defines the overall length of folding frame 100 . The length of vertical member 110 is chosen such that foldable frame device 100 may be placed on the back of user 120 . Vertical member 110 may be approximately two to three feet long. In an aspect, four vertical members 110 are horizontally positioned equal intervals apart and rigidly connected by four cross members spaced at equal intervals along the length of cross members 108 .
[0041] In a second embodiment, two vertical members 110 are positioned approximately two feet apart and rigidly connected by four cross members spaced at equal intervals along the length of vertical members 110 , as shown in FIGS. 9-18 and FIG. 20 .
[0042] In an aspect, cross members 108 are firmly connected to vertical members 110 at end portions of cross members 108 . Firm connection may be made by a bolt, screw, bonding agent or other connection means as will be appreciated by those having skill in the relevant art(s) after reading the description herein. The firm connection may be a permanent or removable connection.
[0043] Cross members 108 and vertical members 110 may be constructed of two to three-inch bars. These bars may be made of metal, aluminum or some other suitable sturdy material.
[0044] Base 104 comprises the bottom cross member 108 of body 102 , one or more cross members 108 and one or more vertical members 110 . Cross members 108 are firmly connected to vertical members 110 at end portions of cross members 108 . The length of base 104 is equal to the length of cross members 108 . The width of base 104 may be approximately one fourth the length of the vertical members 110 located on body 102 . Base 104 is configured to connect to leg 106 at rotatable connection 114 . Rotatable connection 114 (labeled as rotatable connection 114 a - b in FIG. 2 ) may be comprised of one or more hinges or other means as will be appreciated by those skilled in the relevant art(s) after reading the description herein for suitable rotation.
[0045] In an aspect, base 104 is configured to transport assorted items during fishing. In another aspect, base 104 is configured to make contact with a surface such as the ground, sand, rocks or the like. Leg 106 comprises a flat surface area 112 and one or more rotatable connectors 114 . In an aspect, leg 106 may be configured so that the length of leg 106 is approximately one-third the length of body 102 as shown in FIGS. 4 , 5 and 6 . Leg 106 may comprise two or more cross members and two or more vertical members of various arrangements as shown in FIG. 2 . Flat surface area 112 is configured to support assorted items during fishing. In an aspect, flat surface area 112 may comprise a sturdy material such as plastic, mesh or the like, as may be appreciated by those skilled in the relevant art(s) after reading the description herein. Flat surface area 112 may be placed in two positions: a usable position wherein leg 106 is perpendicular to body 102 ( FIG. 2 ) and a folded position ( FIG. 4 ) wherein leg 106 is parallel to body 102 .
[0046] Holder 116 (labeled, for clarity, only as holder 116 a - b in FIG. 2 ) is configured to attach to body 102 at cross member 108 . Holder 116 may be configured to support assorted items such as rods and reels during fishing. Holder 116 may be constructed of one or more sturdy materials such as plastic, metal or steel. Holder 116 may be shaped similar to that of a cylinder. Holder 116 may vary in length, width and height. Holder 116 may be connected to cross members 108 by bolts, screws or other adhesive, as may be appreciated by those having skill in the relevant art(s) after reading the description herein. In an aspect, foldable fame device 100 comprises four holders 116 . In alternative aspects, foldable frame device may comprise more or less holders 116 .
[0047] In an aspect, foldable frame device 100 may further comprise deployable support poles (not shown). The deployable support poles may be extended from foldable frame device 100 , elevating and supporting foldable frame device when placed on the ground.
[0048] Referring now to FIGS. 3A and 3B , a three quarters view of a of a foldable frame device 100 , displaying strap 118 (labeled as straps 118 a - b in FIGS. 3A-B ), in accordance with an aspect of the present disclosure is shown.
[0049] Strap 118 is removably attached to foldable frame 100 at, for example, the top cross member 108 of body 102 . Straps 118 may be placed equal distances apart on top cross member 108 so as to maintain the balance of foldable frame 100 . Straps 118 are adapted to removably connect foldable frame device 100 to a user 120 . Straps 118 may be curved extending over the shoulders of user 120 and underneath the armpits of user 120 , similar to a harness, backpack, or the like as shown in FIGS. 7 and 8 . Straps 118 may be positioned evenly under the armpits to sustain the weight of the assorted items placed on foldable frame 100 . In some aspects, straps 118 may be designed with varying widths. Straps 118 may be adjustable for varying the positioning of foldable frame 100 on the back of user 120 . Straps 118 may be constructed of one or more soft materials such as nylon jersey or mesh. In alternative aspects, one or more handles (not shown in FIGS. 3A and 3B ) may be securely attached to top cross member 108 of body 102 , either removably or permanently, instead of or in addition to straps 118 , to facilitate the movement of device 100 via being gripped and carried by a hand of user 120 .
[0050] Referring now to FIG. 4 , a front view of a foldable frame device 100 wherein leg 106 is in the folded position, in accordance with an aspect of the present disclosure is shown.
[0051] FIG. 4 depicts leg 106 and flat surface area 112 in its folded position. In some aspects, foldable frame device 100 may be folded at rotatable connector 114 (labeled as rotatable connection 114 a - b in FIG. 4 ) for transportation or storage of slim items such as rods and reels or the like. In other aspects, foldable frame device 100 may be folded at rotatable connector 114 for storage in compact spaces. As shown in FIG. 5 , foldable frame device 100 occupies a volume with a similar height, width and approximately three quarters the thickness when folded.
[0052] Foldable frame 100 may be used with a variety of lengths and widths of cross members 108 and vertical members 110 .
[0053] Referring now to FIG. 9 , a perspective view of a second embodiment of a foldable frame device 100 being used, in accordance with an aspect of the present disclosure, is shown.
[0054] The second embodiment of device 100 is substantially similar to the above described version of device 100 and has many of the same parts and components, with a slightly different configuration. In an aspect, the second embodiment of foldable frame device 100 comprises two vertical members 110 (labeled as 110 c - d in FIG. 9 ) positioned approximately two feet apart and rigidly connected by four cross members 108 (labeled only as 108 a in FIG. 9 , for clarity) spaced at equal intervals along the length of vertical members 110 . In such an aspect, leg 106 may contain two cross members 108 (labeled only as 108 c in FIG. 9 , for clarity) and four vertical members 110 (labeled only as 110 e in FIG. 9 , for clarity), or alternative arrangements as may be appreciated by those having skill in the relevant art(s) after reading the description herein.
[0055] Referring now to FIG. 10 , a three quarter view of a second embodiment of a foldable frame device 100 wherein the device leg 106 is extended, in accordance with an aspect of the present disclosure, is shown.
[0056] The second embodiment of device 100 includes additional items. Specifically, the second embodiment of device 100 may further include at least one flexible member 1002 (labeled only as 1002 a in FIG. 10 , for clarity); at least one belt component 1004 (labeled only as 1004 a in FIG. 10 , for clarity); at least one padding element 1006 (labeled on only as 1006 a in FIG. 10 , for clarity); female clasping mechanism 1008 ; and a male clasping mechanism 1010 .
[0057] Flexible member 1002 may securely attach to a vertical member 110 or a cross member 108 of body 102 at one end and a vertical member 110 or a cross member 108 of leg 106 at the opposite end. Flexible member 1002 may comprise a cable, wire, rope, or similar element with an appropriate tensile strength as will be appreciated by those skilled in the relevant art(s) after reading the description herein as being capable of supporting the weight of leg 106 and any one or more of a variety of objects that may be placed thereon, including buckets, fishing gear, and the like. Furthermore, flexible member 1002 may function to prevent leg 106 from rotating more than approximately 90 degrees relative to body 102 when leg 106 is in the extended position, as shown in FIG. 15 . In some aspects, a stopping and/or locking mechanism is integrated with rotatable connector 114 in order to prevent movement of leg 106 past the approximately 90 degree point relative to body 102 . In such aspects, flexible member 1002 may or may not be included with device 100 . In yet some further aspects, the length of flexible member 1002 and/or the configuration of a stopping and/or locking mechanism integrated with rotatable connector 114 may be such as to vary the angle at which leg 106 may be extended relative to body 102 , either less than or greater than 90 degrees.
[0058] Belt component 1004 may be securely attached to vertical members 110 positioned at the outermost opposing sides of body 102 . Belt component 1004 may be integrated with one or more clasping mechanisms, such as, by way of example and not limitation, female clasping mechanism 1008 and male clasping mechanism 1010 . Belt component 1004 may comprise a webbed fabric, nylon jersey, mesh, or similar material as may become apparent to those skilled in the relevant art(s) after reading the description herein as capable of restraining on object positioned on flat surface area 112 , such as bucket 902 (shown in FIG. 9 ) and the like, when the clasping mechanisms 1008 and 1010 are secured within each other. Additionally, belt component 1004 may keep leg 106 in its upright folded position, as shown in FIG. 16 .
[0059] Padding element 1006 may comprise foam-like material, or any other similar material that is soft to the touch as will be appreciated by those skilled in the relevant art(s) after reading the description herein. Padding element 1006 may provide a comforting barrier between vertical member 110 and/or cross member 108 and the back of user 120 when device 100 is worn thereon for transportation, as shown in FIGS. 18 and 21 .
[0060] Referring now to FIG. 17 , a three quarter view of a second embodiment of a foldable frame device 100 being used atop a paddleboard 1804 , in accordance with an aspect of the present disclosure, is shown.
[0061] In some aspects, device 100 may include an additional strap 1802 . Strap 1802 may comprise material similar to belt component 1004 and be used to removably secure device 100 to a variety of surfaces/objects, such as, by way of example and not limitation, paddleboard 1804 . In some aspects, one or more straps 118 and/or belt component 1004 may be removed from device 100 and reattached to different parts thereof in order to secure device 100 to surfaces/objects in conjunction with/instead of strap 1802 .
[0062] In some aspects, device 100 may be configured as a tree stand. Device 100 may include one or more attachment devices suitable for securely, removably connecting device 100 to a tree at a desired height including a tree strap, pitons, and the like. Device 100 may further include a seat cushion and/or back supports for comfort.
[0063] While various aspects of the present disclosure have been described above, it should be understood that they have been presented by way of example and not limitation. It will be apparent to persons skilled in the relevant art(s) that various changes in form and detail can be made therein without departing from the spirit and scope of the present disclosure. Thus, the present disclosure should not be limited by any of the above described exemplary aspects.
[0064] In addition, it should be understood that the figures in the attachments, which highlight the structure, methodology, functionality and advantages of the present disclosure, are presented for example purposes only. The present disclosure is sufficiently flexible and configurable, such that it may be implemented in ways other than that shown in the accompanying figures.
[0065] Further, the purposes of the foregoing Abstract is to enable the U.S. Patent and Trademark Office and the public generally and especially the scientists, engineers and practitioners in the relevant art(s) who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure. The Abstract is not intended to be limiting as to the scope of the present disclosure in any way. | Foldable frame devices designed to transport fishing equipment and assorted items while functioning as a table and which are capable of being stored in confined spaces are disclosed. In an aspect, a foldable frame device may be carried by a user. The foldable frame device includes a rotating flat surface area which may be moved between a folded position and a usable position. In the folded position, the foldable frame device has a compact profile, thereby occupying a small amount of space for transportation or storage when not in use. In the usable position, the flat surface area extends away from the frame and may support items, such as fishing equipment. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Divisional of and claims priority to U.S. Nonprovisional patent application No. 12/426,424 filed Apr. 20, 2009, hereby incorporated by reference herein in its entirety.
FIELD
[0002] The present invention relates to the field of data communications and more particularly relates to a discrete spurious frequency leakage cancellation method and apparatus for use in a cable modem such as a Data Over Cable Service Interface Specification (DOCSIS) compliant cable modem.
BACKGROUND
[0003] Currently there are more than 50 million high-speed Internet access customers in North America. Recently, the cable modem has become the broadband connection of choice for many Internet users, being preferred over the nearest rival broadband technology, Digital Subscriber Line (DSL), by a significant margin.
[0004] Cable modems are well known in the art. A cable modem is a type of modem that provides access to a data signal sent over the cable television (CATV) infrastructure. Cable modems are primarily used to deliver broadband Internet access, taking advantage of unused bandwidth on a cable television network. In 2005 there were over 22.5 million cable modem users in the United States alone.
[0005] A cable modem is a network appliance that enables high speed data connections to the internet via data services provided by the local cable company. Data from the home is sent upstream on a carrier that operates on the 5 MHz to 42 MHz band of the cable spectrum. Downstream data is carried on a 88 MHz to 860 MHz band. The cable modem system can have additional networking features such as Voice over IP (VoIP), wireless connectivity or network switch or hub functionality.
[0006] The term cable Internet access refers to the delivery of Internet service over the cable television infrastructure. The proliferation of cable modems, along with DSL technology, has enabled broadband Internet access in many countries. The bandwidth of cable modem service typically ranges from 3 Mbps up to 40 Mbps or more. The upstream bandwidth on residential cable modem service usually ranges from 384 kbps to 30 Mbps or more. In comparison, DSL tends to offer less speed and more variance between service packages and prices. Service quality is also far more dependent on the client's location in relation to the telephone company's nearest central office or Remote Terminal.
[0007] Users in a neighborhood share the available bandwidth provided by a single coaxial cable line. Therefore, connection speed varies depending on how many people are using the service at the same time. In most areas this has been eliminated due to redundancy and fiber networks.
[0008] With the advent of Voice over IP telephony, cable modems are also being used to provide telephone service. Many people who have cable modems have opted to eliminate their Plain Old Telephone Service (POTS). An alternative to cable modems is the Embedded Multimedia Terminal Adapter (EMTA). An EMTA allows multiple service operators (MSOs) to offer both High Speed Internet and VoIP through a single piece of customer premise equipment. A multiple system operator is an operator of multiple cable television systems.
[0009] Many cable companies have launched Voice over Internet Protocol (VoIP) phone service, or digital phone service, providing consumers a true alternative to standard telephone service. Digital phone service takes the analog audio signals and converts them to digital data that can be transmitted over the fiber optic network of the cable company. Cable digital phone service is currently available to the majority of U.S. homes with a large number of homes are now subscribing. The number of homes subscribing is currently growing by hundreds of thousands each quarter. One significant benefit of digital phone service is the substantial consumer savings, with one recent study saying residential cable telephone consumers could save an average of $135 or more each year.
[0010] The Data Over Cable Service Interface Specification (DOCSIS) compliant cable modems have been fueling the transition of cable television operators from a traditional core business of entertainment programming to a position as full-service providers of video, voice, and data telecommunications services.
[0011] Cable systems transmit digital data signals over radio frequency (RF) carrier signals. To provide two-way communication, one carrier signal carries data in the downstream direction from the cable network to the customer and another carrier signal carries data in the upstream direction from the customer to the cable network. Cable modems are devices located at the subscriber premises that functions to convert digital information into a modulated RF signal in the upstream direction, and to convert the RF signals to digital information in the downstream direction. A cable modem termination system (CMTS) performs the opposite operation for multiple subscribers at the cable operator's head-end.
[0012] Typically, several hundreds of users share a 6 MHz downstream channel and one or more upstream channels. The downstream channel occupies the space of a single television transmission channel in the cable operator's channel lineup. It is compatible with digital set top MPEG transport stream modulation (64 or 256 QAM), and provides up to 40 Mbps. A media access control (MAC) layer coordinates shared access to the upstream bandwidth.
[0013] The DOCSIS 2.0 specification provides for both more efficient modulation techniques and increased RF channel bandwidth in the return path under two different allowed multi-access protocols: a time division multi-access (TDMA) protocol and a synchronous code division multi-access (S-CDMA) protocol. Under the DOCSIS 2.0 TDMA protocol, the maximum allowed RF channel bandwidth is increased from 3.2 to 6.4 MHz and three new higher-order modulation techniques are specified: 8 QAM, 32 QAM, and 64 QAM. As a result, the maximum raw data rate is increased from 10.24 Mbps in the case of DOCSIS 1.0/1.1 (16 QAM in 3.2 MHz) to 30.72 Mbps (64 QAM in 6.4 MHz).
[0014] Under TDMA, individual channel users are assigned a distinct time slot during which they transmit a QAM burst that encodes multiple information bits. Under CDMA, the in-phase and quadrature (I and Q) components of each QAM symbol are first encoded into a stream of sub-bits, or ‘chips’. Each user is assigned one or more distinct code chip sequences that are recognized by a matched correlator at the receiver that rejects all other users' code sequences. In this manner, multiple users are able to transmit simultaneously in the same time slot. The DOCSIS S-CDMA protocol is actually a time division multiplexed CDMA that employs 128-chip spreading codes and mini-time slots spanning multiple CDMA symbols.
[0015] A potential problem in the design of cable modems is spurious emissions from signal leakage from the PHY circuitry into the upstream path. Out of band spurious emissions can be filtered out relatively easily. In-band spurious emissions, however, are more difficult to eliminate.
[0016] In accordance with the DOCSIS 2.0 specification, the spurious emissions specifications are separated into two regions based on the transmit power. Region 1 is defined to have a power range of +14 dBmV to (Pmax−3), i.e. the central region. Region 2 is defined from +8 dBmV to +14 dBmV and (Pmax−3) to Pmax, i.e. the low and high ends of the transmit power.
[0017] For S-CDMA mode, when a modem is transmitting fewer than four spreading codes, the region 2 specifications are used for all transmit power levels. Otherwise, for all other numbers of spreading codes (e.g., 4 to 128) or for TDMA mode, the spurious emissions specifications are used according to the power ranges defined for regions 1 and 2 above.
[0018] The noise and spurious power cannot exceed the levels given in Table 1 below.
[0000]
TABLE 1
DOCSIS 2.0 Spurious Emissions
Parameter
Transmitting Burst
Between Bursts
Inband
−40 dBc
The greater of −72 dBc
or −59 dBmV
Adjacent Band
See Table 6-10
The greater of −72 dBc
or −59 dBmV
3 or Fewer Carrier-
Region 1: −50 dBc
The greater of −72 dBc
Related Frequency
for transmitted
or −59 dBmV
Bands (such as second
modulation
harmonic, if < 42 MHz)
rate = 320 ksps and
above; −47 dBc for
transmitted
modulation
rate = 160 ksps
Region 2: −47 dBc
Bands within 5 to 42
See Table 6-11
The greater of −72 dBc
MHz (excluding
or −59 dBmV
assigned channel,
adjacent channels, and
carrier-related channels)
CM Integrated Spurious
Emissions Limits
(all in 4 MHz,
includes discretes) 1
42 to 54 MHz
max (−40 dBc,
−26 dBmV
−26 dBmV)
54 to 60 MHz
−35 dBmV
−40 dBmV
60 to 88 MHz
−40 dBmV
−40 dBmV
88- to 860 MHz
−45 dBmV
max (−45 dBmV,
−40 dB ref d/s 2 )
CM Discrete Spurious
Emissions Limits 1
42 to 54 MHz
−max (−50 dBc,
−36 dBmV
−36 dBmV)
54 to 88 MHz
−50 dBmV
−50 dBmV
88 to 860 MHz
−50 dBmV
−50 dBmV
[0019] In Table 1 above, in-band spurious emissions may include noise, carrier leakage, clock signal lines, synthesizer spurious products and other undesired transmitter products. The measurement bandwidth for in-band spurious is equal to the modulation rate (e.g., 160 to 5120 kHz). All requirements expressed in dBc are relative to the actual transmit power that the cable modem emits.
[0020] The measurement bandwidth for the three (or fewer) Carrier-Related Frequency Bands (below 42 MHz) is 160 kHz, with up to three 160 kHz bands, each with no more than the value given in Table 1, allowed to be excluded from the “Bands within 5 to 42 MHz Transmitting Burst” specifications of Table 2 below. Carrier-related spurious emissions include all products whose frequency is a function of the carrier frequency of the upstream transmission, such as but not limited to carrier harmonics. The measurement bandwidth is also 160 kHz for the Between Bursts specifications of Table 1 below 42 MHz.
[0021] The Transmitting Burst specifications apply during the mini-slots granted to the cable modem (when the cable modem uses all or a portion of the grant), and for 32 modulation intervals before and after the granted mini-slots. The Between Bursts specifications apply except during a used grant of mini-slots, and the 32 modulation intervals before and after the used grant.
[0022] In TDMA mode, a mini-slot may be as short as 32 modulation intervals, or 6.25 microseconds at the 5.12 Msymbol/sec rate, or as short as 200 microseconds at the 160 ksym/sec rate.
[0000]
TABLE 2
Spurious Emissions in 5 to 42 MHz Relative to the Transmitted Burst
Power Level
Possible
Specification
Specification
Initial measurement
modulation rate
in the interval,
in the interval,
interval and distance
in this interval
Region 1
Region 2
from carrier edge
160 kHz
−54 dBc
−53 dBc
220 kHz to 380 kHz
320 kHz
−52 dBc
−50 dBc
240 kHz to 560 kHz
640 kHz
−50 dBc
−47 dBc
280 kHz to 920 kHz
1280 kHz
−48 dBc
−44 dBc
360 kHz to 1640 kHz
2560 kHz
−46 dBc
−41 dBc
520 kHz to 3080 kHz
5120 kHz
−44 dBc
−38 dBc
840 kHz to 5960 kHz
[0023] In the worst case, the maximum spurious level relative to the transmission level permitted during transmission is −54 dBc. Spurious emissions, other than those in an adjacent channel or carrier related emissions listed above, may occur in intervals (frequency bands) that could be occupied by other carriers of the same or different modulation rates. To accommodate these different modulation rates and associated bandwidths, the spurious emissions are measured in an interval equal to the bandwidth corresponding to the modulation rate of the carrier that could be transmitted in that interval. This interval is independent of the current transmitted modulation rate.
[0024] Table 2 above lists the possible modulation rates that could be transmitted in an interval, the required spurious level in that interval, and the initial measurement interval at which to start measuring the spurious emissions. Typically, the modulation is set by the CMTS utilizing the downstream link.
[0025] For example, consider a 35 MHz clock used to drive a cable modem PHY that leaks to the output of a PGA circuit output at a sufficiently high magnitude to cause a violation of the DOCSIS in-band spurious level specifications. The magnitude of the leakage will typically vary by the particular PCB payout used and the configuration of the 1.5 V decoupling capacitors.
[0026] In the worst case, for DOCSIS 2.0 for bands within 5 to 42 MHz, the maximum allowed spurious emissions between transmission bursts is -59 dBmV which translates to approximately −107.75 dBm or 1.122 μV on 75 ohm. A spur emitted at 35 MHz (PHY clock driver) cannot be filtered because is falls within the upstream frequency range of 5 to 42 MHz.
[0027] One approach to solving this problem is to modify the design of the PHY circuit which may be a complex, FPGA or ASIC. A disadvantage of this approach is complicated and very expensive process (in terms of human resources) of analyzing and investigating the circuit to find the leakage path. Therefore, in the case of in-band spurious emissions (e.g., noise, carrier leakage, clock signal lines, synthesizer spurious products, etc.), a mechanism is needed to substantially minimize or cancel the spurious emissions. The mechanism should meet the requirements of the DOCSIS cable modem specification and operate efficiently, be of low complexity, exhibit high performance, consume minimal board and chip area and be able to be manufactured at low cost.
SUMMARY
[0028] The present invention is a novel apparatus for and method of discrete spurious frequency leakage cancellation for use in a cable modem. The spurious leakage cancellation mechanism is particularly suitable for use in cable modem systems adapted to implement the DOCSIS 2.0 specification which specifies both downstream and upstream channels.
[0029] In one embodiment, the spurious emission cancellation mechanism cancels the spurious emissions by first creating a replica of the aggressor clock signal having the same amplitude but 180 degree phase shift as the spurious signal. The phase shifted spurious replica is added to the original spurious signal thus cancelling the spurious signal.
[0030] In another embodiment, an RF switch is used to couple the upstream path signal to the CATV cable only during transmission bursts. In between transmission bursts, the upstream signal is disconnected from the CATV cable. This embodiment takes advantage of the less stringent spurious requirements in the DOCSIS 2.0 specification for transmission bursts. In between transmission bursts, when stricter spurious requirements apply, the upstream signal is disconnected from the CATV cable.
[0031] To aid in understanding the principles of the present invention, the description is provided in the context of a DOCSIS 2.0 capable cable system comprising a cable modem adapted to receive an DOCSIS compatible RF signal feed from a cable head-end (i.e. CMTS) and to distribute video, Internet and telephony to a subscriber premises. It is appreciated, however, that the invention is not limited to use with any particular communication device or standard and may be used in optical, wired and wireless applications. Further, the invention is not limited to use with a specific technology but is applicable to any transmission circuit wherein it is desirable to cancel or substantially eliminate in-band spurious emissions.
[0032] Several advantages of the discrete spurious leakage cancellation mechanism of the present invention include (1) relatively low cost of manufacturing; (2) stable circuit operation over temperature and voltage fluctuations; (3) simple and clear implementation to satisfy users and customers; (4) relatively to implement; and (5) can be removed from the cable modem circuit design without requiring changes to the PCB layout.
[0033] Note that many aspects of the invention described herein may be constructed as software objects that are executed in embedded devices as firmware, software objects that are executed as part of a software application on either an embedded or non-embedded computer system running a real-time operating system such as WinCE, Symbian, OSE, Embedded LINUX, etc. or non-real time operating system such as Windows, UNIX, LINUX, etc., or as soft core realized HDL circuits embodied in an Application Specific Integrated Circuit (ASIC) or Field Programmable Gate Array (FPGA), or as functionally equivalent discrete hardware components.
[0034] There is thus provided in accordance with the present invention, a circuit for canceling frequency spurs from a victim signal, the frequency spurs originating from an aggressor clock source comprising a canceling clock source for generating a canceling clock signal, a conditioning circuit operative to generate an amplitude and phase adjusted cancellation signal from the canceling clock source and combining means for applying the cancellation signal to the victim signal thereby substantially canceling the frequency spurs.
[0035] There is also provided in accordance with the present invention, a method of canceling frequency spurs from a victim signal, the frequency spurs originating from an aggressor clock source, the method comprising the steps of providing a canceling clock source for generating a canceling clock signal, conditioning the canceling clock signal to generate an amplitude and phase adjusted cancellation signal therefrom and combining the cancellation signal with the victim signal to generate an output signal having substantially reduced frequency spur energy.
[0036] There is further provided in accordance with the present invention, a cable modem connected to a Community Antenna Television (CATV) infrastructure comprising a memory, one or more interface ports, a downstream path including a tuner, an upstream path for generating an upstream signal to be transmitted over the CATV infrastructure, the upstream path comprising a canceling clock source for generating a canceling clock signal, a conditioning circuit operative to generate an amplitude and phase adjusted cancellation signal from the canceling clock source, combining means for applying the cancellation signal to the upstream signal thereby substantially canceling the frequency spurs, a PHY circuit coupled to the downstream path and the upstream path and a processor coupled to the memory, the one or more interface ports and the PHY circuit, the processor operative to implement a media access control (MAC) layer operative to generate an output video stream.
[0037] There is also provided in accordance with the present invention, a circuit for canceling frequency spurs from a victim signal, the frequency spurs derived from an aggressor clock source comprising a radio frequency (RF) switch having an output and operative to connect and disconnect the victim signal to the output in accordance with a switch control signal and a switch control module operative to generate the switch control signal, wherein the victim signal is coupled to the RF switch output during transmission bursts only.
[0038] There is further provided in accordance with the present invention, a method of canceling frequency spurs from a victim signal, the frequency spurs originating from an aggressor clock source, the method comprising the steps of providing a radio frequency (RF) switch having an output and operative to connect and disconnect the victim signal to the output in accordance with a switch control signal and generating the switch control signal whereby the victim signal is coupled to the RF switch output during transmission bursts only.
[0039] There is also provided in accordance with the present invention, a cable modem connected to a Community Antenna Television (CATV) infrastructure comprising a memory, one or more interface ports, a downstream path including a tuner, an upstream path for generating an upstream signal to be transmitted over the CATV infrastructure, the upstream path including a radio frequency (RF) switch having an output and operative to connect and disconnect the upstream signal to the output in accordance with a switch control signal, a PHY circuit coupled to the tuner and the RF switch, the PHY circuit comprising a switch control module operative to generate the switch control signal, wherein the upstream signal is coupled to the RF switch output during transmission bursts only and a processor coupled to the memory, the one or more interface ports and the PHY circuit, the processor operative to implement a media access control (MAC) layer operative to generate an output video stream.
BRIEF DESCRIPTION OF THE DRAWINGS
[0040] The invention is herein described, by way of example only, with reference to the accompanying drawings, wherein:
[0041] FIG. 1 is a block diagram illustrating an example cable modem system incorporating the upstream system of the present invention;
[0042] FIG. 2 is a block diagram illustrating an example cable modem including an upstream system incorporating the spur reduction mechanism of the present invention;
[0043] FIG. 3 is a simplified block diagram illustrating the processor of the cable modem of FIG. 2 including an upstream system incorporating a first embodiment of the spur reduction mechanism of the present invention;
[0044] FIG. 4 is a schematic diagram illustrating the spur cancellation circuit of FIG. 3 in more detail;
[0045] FIG. 5 is a block diagram illustrating a model of a portion of the upstream circuit without the spur cancellation mechanism of the present invention;
[0046] FIG. 6 is a block diagram illustrating a model of a portion of the upstream circuit incorporating the spur cancellation mechanism of the present invention;
[0047] FIG. 7 is a spectrum plot illustrating frequency response of the spur cancellation circuits of FIGS. 5 and 6 ;
[0048] FIG. 8 is a time domain plot of the spur without the spur cancellation mechanism of the present invention;
[0049] FIG. 9 is a frequency spectrum of the spur of FIG. 8 ;
[0050] FIG. 10 is a time domain plot of the spur with the spur cancellation mechanism of the present invention;
[0051] FIG. 11 is a frequency spectrum of the spur of FIG. 10 ; and
[0052] FIG. 12 is a simplified block diagram illustrating the processor of the cable modem of FIG. 2 including an upstream system incorporating a second embodiment of the spur reduction mechanism of the present invention;
DETAILED DESCRIPTION
Notation Used Throughout
[0053] The following notation is used throughout this document.
[0000]
Term
Definition
AC
Alternating Current
ADC
Analog to Digital Converter
ASIC
Application Specific Integrated Circuit
ATM
Asynchronous Transfer Mode
CATV
Community Antenna Television or Cable TV
CDMA
Code Division Multiple Access
CM
Cable Modem
CMTS
Cable Modem Termination System
CO
Central Office
CPU
Central Processing Unit
DAC
Digital to Analog Converter
DCAS
Downloadable Conditional Access Systems
DECT
Digital Enhanced Cordless Telecommunications
DHCP
Dynamic Host Control Protocol
DOCSIS
Data Over Cable Service Interface Specification
DS
Downstream
DSL
Digital Subscriber Line
DSP
Digital Signal Processor
DVR
Digital Video Recorder
EEROM
Electrically Erasable Read Only Memory
EMTA
Embedded Multimedia Terminal Adapter
FPGA
Field Programmable Gate Array
GPIO
General Purpose I/O
HDL
Hardware Description Language
I/F
Interface
I/O
Input/Output
IC
Integrated Circuit
IP
Internet Protocol
LAN
Local Area Network
LED
Light Emitting Diode
MAC
Media Access Control
MPEG
Moving Picture Experts Group
MSO
Multiple Service Operator
NB
Narrowband
PC
Personal Computer
PC
Personal Computer
PCB
Printed Circuit Board
PCC
Passive Cancellation Circuit
PDA
Personal Digital Assistant
PGA
Programmable Gain Amplifier
PLL
Phase Locked Loop
POTS
Plain Old Telephone Service
PSTN
Public Switched Telephone Network
QAM
Quadrature Amplitude Modulation
RAM
Random Access Memory
RF
Radio Frequency
ROM
Read Only Memory
SLIC
Subscriber Line Interface Card
SONET
Synchronous Optical Network
SPDT
Single Pole Double Throw
TB
Tuning Band
TDMA
Time Division Multiple Access
US
Upstream
USB
Universal Serial Bus
VCO
Voltage Controlled Oscillator
VGA
Variable Gain Amplifier
VoIP
Voice over IP
WAN
Wide Area Network
WB
Wideband
WLAN
Wireless Local Area Network
DETAILED DESCRIPTION
[0054] Embodiments of the invention are a novel apparatus for and method of discrete spurious frequency leakage cancellation for use in a cable modem. The spurious leakage cancellation mechanism is particularly suitable for use in cable modem systems adapted to implement the DOCSIS 2.0 specification which specifies both downstream and upstream channels.
[0055] To aid in understanding the principles of the present invention, the description is provided in the context of a DOCSIS 2.0 capable cable system comprising a cable modem adapted to receive an DOCSIS compatible RF signal feed from a cable head-end (i.e. CMTS) and to distribute video, Internet and telephony to a subscriber premises. It is appreciated, however, that the invention is not limited to use with any particular communication device or standard and may be used in optical, wired and wireless applications. Further, the invention is not limited to use with a specific technology but is applicable to any transmission circuit wherein it is desirable to cancel or substantially eliminate in-band spurious emissions.
[0056] It is noted that the spur reduction mechanism of the present invention can be used in cable modems designed for use not only in North America, but also for use with the Euro DOCSIS standard using a similar configuration.
[0057] Note that throughout this document, the term communications device is defined as any apparatus or mechanism adapted to transmit, or transmit and receive data through a medium. The communications device may be adapted to communicate over any suitable medium such as RF, wireless, infrared, optical, wired, microwave, etc. In the case of wireless communications, the communications device may comprise an RF transmitter, RF receiver, RF transceiver or any combination thereof.
[0058] The term cable modem is defined as a modem that provides access to a data signal sent over the cable television infrastructure. The term voice cable modem is defined as a cable modem that incorporates VoIP capabilities to provide telephone services to subscribers
Cable System Incorporating Spur Reduction Mechanism
[0059] A block diagram illustrating a cable modem system incorporating the upstream system of the present invention is shown in FIG. 1 . The system, generally referenced 10 , comprises an operator portion 11 connected to the public switched telephone network (PSTN) 12 and the Internet 14 or other wide area network (WAN), a link portion 13 comprising the RF cable 28 and a subscriber portion 15 comprising the subscriber premises 34 .
[0060] The operator portion 11 comprises the cable head-end 17 which is adapted to receive a number of content feeds such as satellite 16 , local antenna 18 and terrestrial feeds 26 , all of which are input to the combiner 24 . The cable head-end also comprises the voice over IP (VoIP) gateway 20 and Cable Modem Termination System (CMTS) 22 . The combiner merges the TV programming feeds with the RF data from the CMTS.
[0061] The Cable Modem Termination System (CMTS) is a computerized device that enables cable modems to send and receive packets over the Internet. The IP packets are typically sent over Layer 2 and may comprise, for example, Ethernet or SONET frames or ATM cell. It inserts IP packets from the Internet into MPEG frames and transmits them to the cable modems in subscriber premises via an RF signal. It does the reverse process coming from the cable modems. A DOCSIS-compliant CMTS enables customer PCs to dynamically obtain IP addresses by acting as a proxy and forwarding DHCP requests to DHCP servers. A CMTS may provide filtering to protect against theft of service and denial of service attacks or against hackers trying to break into the cable operator's system. It may also provide traffic shaping to guarantee a specified quality of service (QoS) to selected customers. A CMTS may also provide bridging or routing capabilities.
[0062] The subscriber premises 34 comprises a splitter 38 , cable appliances 36 such as televisions, DVRs, etc., cable modem 40 , router 48 , PCs or other networked computing devices 47 and telephone devices 51 . Cable service is provided by the local cable provider wherein the cable signal originates at the cable head end facility 17 and is transmitted over RF cable 28 to the subscriber premises 34 where it enters splitter 38 . One output of the splitter goes to the televisions, set top boxes, and other cable appliances via internal cable wiring 37 .
[0063] The other output of the splitter comprises the data portion of the signal which is input to the cable modem 40 . The cable modem is adapted to provide both Ethernet and USB ports. Typically, a router 48 is connected to the Ethernet port via Ethernet cable 54 . One or more network capable computing devices 47 , e.g., laptops, PDAs, desktops, etc. are connected to the router 48 via internal Ethernet network wiring 46 . In addition, the router may comprise or be connected to a wireless access point that provides a wireless network (e.g., 802.11b/g/a) throughout the subscriber premises.
[0064] The cable modem also comprises a subscriber line interface card (SLIC) 42 which provides the call signaling and functions of a conventional local loop to the plurality of installed telephone devices 51 via internal 2-wire telephone wiring 52 . In particular, it generates call progress tones including dial tone, ring tone, busy signals, etc. that are normally provided by the local loop from the CO. Since the telephone deices 51 are not connected to the CO, the SLIC in the cable modem must provide these signals in order that the telephone devices operate correctly.
[0065] The cable modem also comprises a downstream system (not shown) and an upstream system 44 which incorporates the spur reduction mechanism of the present invention. A digital video output signal is displayed to the user (i.e. cable subscribers) via televison set 53 (i.e. video display device or other cable appliance).
DOCSIS 2.0 Channel Cable Modem
[0066] A block diagram illustrating an example cable modem including an upstream system incorporating the spur reduction mechanism of the present invention is shown in FIG. 2 . The cable modem, generally referenced 70 , comprises a duplexer 74 , CATV RF tuner circuit 76 incorporating, DOCSIS PHY (analog/digital) 78 , DOCSIS compatible processor 80 , DOCSIS MAC 82 , VoIP processor 108 , voice codec 110 , subscriber line interface card (SLIC) 112 , phone port 114 , wireless local area network (WLAN) 122 and associated antenna 120 , DECT 126 and associated antenna 124 , Bluetooth 130 and associated antenna 128 , Ethernet interface 96 , Ethernet LAN ports 98 , general purpose (I/O) (GPIO) interface 100 , LEDs 102 , universal serial bus (USB) interface 104 , USB port 106 , cable card/Downloadable Conditional Access Systems (DCAS) 92 , video interface (I/F) 94 , video processor 90 , upstream system 116 including spur reduction circuit 118 , AC adapter 134 coupled to mains utility power via plug 132 , power management circuit 136 , battery 138 , RAM 84 , ROM 86 and FLASH memory 88 .
[0067] Note that in the example embodiment presented herein, the cable modem and DOCSIS enabled processor are adapted to implement the DOCSIS 2.0 standard. Although the invention is applicable to cable modems designed to implement this standard, the invention is not limited to use therein. It can be applied to other standards and systems, and should not be limited to use in the example cable modem application presented herein.
[0068] In operation, the cable modem processor is the core chip set which in the example presented herein comprises a central single integrated circuit (IC) with peripheral functions added. The voice over IP (VoIP) processor 108 implements a mechanism to provide phone service outside the standard telco channel. Chipset DSPs and codecs 96 add the functionality of POTS service for low rate voice data.
[0069] The cable modem also comprises a subscriber line interface card (SLIC) 112 which functions to provide the signals and functions of a conventional local loop to a plurality of telephone devices connected via the phone port 114 using internal 2-wire telephone wiring. In particular, it generates call progress tones including dial tone, ring tone, busy signals, etc. that are normally provided by the local loop from the CO. Since the telephone deices are not connected to the CO, the SLIC in the cable modem must provide these signals in order that the telephone devices operate correctly.
[0070] In a traditional analog telephone system, each telephone or other communication device (i.e. subscriber unit) is typically interconnected by a pair of wires (commonly referred to as tip and ring or together as subscriber lines, subscriber loop or phone lines) through equipment to a switch at a local telephone company office (central office or CO). At the CO, the tip and ring lines are interconnected to a SLIC which provides required functionality to the subscriber unit. The switches at the central offices are interconnected to provide a network of switches thereby providing communications between a local subscriber and a remote subscriber.
[0071] The SLIC is an essential part of the network interface provided to individual analog subscriber units. The functions provided by the SLIC include providing talk battery (between 5 VDC for on-hook and 48 VDC for off-hook), ring voltage (between 70-90 VAC at a frequency of 17-20 Hz), ring trip, off-hook detection, and call progress signals such as ringback, busy, and dial tone.
[0072] A SLIC passes call progress tones such as dial tone, busy tone, and ringback tone to the subscriber unit. For the convenience of the subscriber who is initiating the call, these tones normally provided by the central office give an indication of call status. When the calling subscriber lifts the handset or when the subscriber unit otherwise generates an off hook condition, the central office generates a dial tone and supplies it to the calling subscriber unit to indicate the availability of phone service. After the calling subscriber has dialed a phone number of the remote (i.e. answering) subscriber unit, the SLIC passes a ring back sound directed to the calling subscriber to indicate that the network is taking action to signal the remote subscriber, i.e. that the remote subscriber is being rung. Alternatively, if the network determines that the remote subscriber unit is engaged in another call (or is already off-hook), the network generates a busy tone directed to the calling subscriber unit.
[0073] The SLIC also acts to identify the status to, or interpret signals generated by, the analog subscriber unit. For example, the SLIC provides −48 volts on the ring line, and 0 volts on the tip line, to the subscriber unit. The analog subscriber unit provides an open circuit when in the on-hook state. In a loop start circuit, the analog subscriber unit goes off-hook by closing, or looping the tip and ring to form a complete electrical circuit. This off-hook condition is detected by the SLIC (whereupon a dial tone is provided to the subscriber). Most residential circuits are configured as loop start circuits.
[0074] Connectivity is provided by a standard 10/100/1000 Mbps Ethernet interface 96 and Ethernet LAN port 98 , USB interface 104 and USB port 106 or with additional chip sets, such as wireless 802.11a/b/g via WLAN interface 122 coupled to antenna 120 . In addition, a GPIO interface 100 provides an interface for LEDs 102 , etc. The network connectivity functions may also include a router or Ethernet switch core. Note that the DOCSIS MAC 82 and PHY 78 may be integrated into the cable modem processor 80 or may be separate.
[0075] In the example embodiment presented herein, the tuner 76 is coupled to the CATV signal from the CMTS via port 72 and is operative to convert the RF signal received over the RF cable to an IF frequency in accordance with the tune command signals received from the processor.
[0076] The cable modem 70 comprises a processor 80 which may comprise a digital signal processor (DSP), central processing unit (CPU), microcontroller, microprocessor, microcomputer, ASIC, FPGA core or any other suitable processing means. The cable modem also comprises static read only memory (ROM) 86 , dynamic main memory 84 and FLASH memory 88 all in communication with the processor via a bus (not shown).
[0077] The magnetic or semiconductor based storage device 84 (i.e. RAM) is used for storing application programs and data. The cable modem comprises computer readable storage medium that may include any suitable memory means, including but not limited to, magnetic storage, optical storage, semiconductor volatile or non-volatile memory, biological memory devices, or any other memory storage device.
[0078] Any software required to implement the spur reduction mechanism of the present invention is adapted to reside on a computer readable medium, such as a magnetic disk within a disk drive unit. Alternatively, the computer readable medium may comprise a floppy disk, removable hard disk, Flash memory, EEROM based memory, bubble memory storage, ROM storage, distribution media, intermediate storage media, execution memory of a computer, and any other medium or device capable of storing for later reading by a computer a computer program implementing the system and methods of this invention. The software adapted to implement the spur reduction mechanism of the present invention may also reside, in whole or in part, in the static or dynamic main memories or in firmware within the processor of the computer system (i.e. within microcontroller, microprocessor or microcomputer internal memory).
Spur Reduction Mechanism
[0079] In accordance with the invention, two solutions are presented to reduce or eliminate the spurious emission leakage problem whereby the clock (e.g., 35 MHz clock) that drives the PHY circuit leaks to the output of the PGA circuit causing the cable modem to violate DOCSIS limits on spurious emission levels.
[0080] The first embodiment for reducing the spur power level comprises a passive cancellation circuit (PCC). This circuit uses the 35 MHz PHY clock, available from a dedicated pin on the PHY integrated circuit (IC), and creates from it a modified amplitude and phase cancellation signal. This cancellation signal is applied to the single ended output of the balun before the diplexer, thereby cancelling the spur power present at that point.
[0081] The second embodiment for reducing the spur power level comprises an RF switch whereby an RF switch is inserted into the US path between the PGA's balun and diplexer. The RF switch provides wideband isolation between US transmission bursts, reducing the 35 MHz spur power, in addition to any additional power that may reside in the bandwidth of the transmitted signal.
[0082] The first embodiment is preferred due its lower cost and is the more robust solution that meets DOCSIS specifications. The second embodiment has application in cases where there is concern for additional noise injection into the RF output from the PCB assembly. Each of the embodiments will now be described in more detail.
First Embodiment: Spur Cancellation Circuit
[0083] A simplified block diagram illustrating the processor of the cable modem of FIG. 2 including an upstream system incorporating a first embodiment of the spur reduction mechanism of the present invention is shown in FIG. 3 . The example cable modem, generally referenced 150 , comprises diplexer 154 coupled to a CATV input 152 , RF tuner circuit 156 , processor 158 and upstream path circuit 116 .
[0084] The upstream circuit 116 comprises image reject filter 172 , PGA 174 , balun 176 and spur cancellation circuit 177 . The processor 158 comprises an analog to digital converter (ADC) 160 , PHY circuit 162 , digital to analog converter (DAC) 170 , PGA control circuit 178 , power supply control 180 and MAC 168 . Power is supplied by an external power source 182 e.g., utility power, etc. or a battery 184 .
[0085] In operation, in the downstream (i.e. receive) direction, the receive signal from the diplexer is input to the CATV RF tuner circuit 156 . The tuner output signal is input to the ADC to provide I and Q input signals to the PHY circuit. The PHY circuit provides a tuner control signal 157 that controls the tuning of the tuner circuit. After MAC processing, one or more MPEG video streams 169 are output of the cable modem.
[0086] In the upstream (US) (i.e. transmit) direction, a digital TX output signal provided by the PHY circuit is converted to analog by the DAC. The analog signal is then filtered via the image reject filter 172 before being amplified by the PGA whose gain is controlled by a PGA control signal 173 generated by the PGA control circuit 178 .
[0087] The output of the PGA circuit is input to one side of the balun 176 . The other side of the balun is input to the diplexer 154 which couples the US signal to the CATV cable 152 . In accordance with the invention, spur cancellation circuit 177 functions to substantially cancel the in-band spurious emissions from the US signal before input to the diplexer.
[0088] The spur cancellation circuit is operative to adjust the amplitude and phase of the 35 MHz MPEG clock 179 such that when combined with the US signal, the spur signals are cancelled or substantially cancelled. Note that the spur cancellation circuit operates both during US transmission bursts and in between bursts. The 35 MHz MPEG clock is used to generate the cancellation signal assuming that the source of the spur is the PHY clock, which is based on the 35 MHz MPEG clock. It is appreciated that the source signal used to generate the cancellation signal is not limited to the clock shown in the example circuit presented herein but can be any clock or other signal source depending on the particular implementation of the invention.
[0089] The spur cancellation circuit 177 is essentially a passive cancellation circuit (PCC). It is based on the assumption that the interfering frequency spur is narrow band and has predictable characteristics of frequency, phase and amplitude. The 35 MHz spur that is coupled to the output path of the PGA is dependent on the particular ground separation regime implemented and the 1.5 V digital power supply decoupling capacitor arrangement. It is preferable that there be a single solid ground (including the PGA ground) and to use decoupling capacitors of 1 nF or less on the digital 1.5 V power supply network. Experiments by the inventors have shown that this configuration results in a spur level of less then −55 dBmV. Use of the spur cancellation circuit of the present invention reduces this level further.
[0090] The 35 MHz clock 179 (internal or external) is highly correlative with the DOCSIS PHY clock (which is the source of the spur). The spur cancellation circuit 177 functions to condition the amplitude and phase of the MPEG clock. After signal conditioning, the clock signal is applied to the output of the balun 176 . This reduces the level of the spur to a worst case of −61 dBmV and a typical level of −7 dBmV over temperature and sample variation and +/−5% voltage changes, which translates to a 6 dB mnimum/12 dB typical improvement.
[0091] The MPEG clock output 179 is a digital 3.3 V peak-to-peak clock signal which translates to 64 dBmV. The amplitude of the cancellation signal 181 preferably should be equal to the amplitude of the spur, i.e. −55 dBmV. Thus, a relatively high attenuation of approximately 120 dB is required, The exact attenuation can be determined empirically for maximum cancellation.
[0092] The phase of the cancellation signal 181 (relative to the MPEG clock) is set empirically for maximum cancellation. Measurements have shown that a good starting point is −95 degrees.
[0093] A schematic diagram illustrating the spur cancellation circuit of FIG. 3 in more detail in shown in FIG. 4 . The circuit shown herein represents a preferred amplitude and phase conditioning scheme. It is appreciated that other schemes using other circuit topologies may be used to achieve similar results without departing from the scope of the invention.
[0094] The circuit, generally referenced 177 , comprises resistors R 1 , R 2 , R 3 , R 4 , R 5 and capacitors C 1 , C 2 . Example values of the resistor and capacitor component values for circuit 177 are given below in Table 3.
[0000]
TABLE 3
Example component values
Component
Value
R1
100 kOhm
R2
1000 Ohm
R3
100 kOhm
R4
1000 Ohm
R5
3320 Ohm
C1
6 pF
C2
6 pF
[0095] The variance of the components may be configured such that its impact on the overall spur cancellation is negligible. For example, consider resistor accuracy of 1% and capacitor accuracy of 5%. Under these conditions, the component variance results in an amplitude variation of +/−0.6 dB and phase variation of +/−3 degrees. The variation in amplitude translates to a cancellation limitation of −23.5 dB and phase variation translates to a cancellation limitation of −25.62 dB. The total cancellation limitation (i.e. amplitude and phase) is −21.dB, i.e. −76 dBmV.
[0096] Note that the impedance looking into the circuit 177 is 1 Ohm. The output impedance is 75 Ohm (i.e. the characteristic impedance of the cable modem) to match the impedance of the CATV cable.
[0097] In operation, resistors R 1 /R 2 and R 3 /R 4 form voltage dividers which function to significantly attenuate the MPEG clock signal. Capacitors C 1 and C 2 function to shift the phase of the MPEG clock signal. The result is a cancellation signal having a phase opposite that of the spur. When combined to the output of the balun, the spur is reduced sufficiently to meet DOCSIS requirements.
[0098] This approach to spur reduction has several advantages, including (1) very low cost (i.e. only a few resistors and capacitors are required); (2) relatively very quick implementation; and (3) no need for external control such as is required in the case of an RF switch (second embodiment).
[0099] A block diagram illustrating a model of a portion of the upstream circuit without the spur cancellation mechanism of the present invention is shown in FIG. 5 . The circuit, generally referenced 200 , comprises SRC 1 (the source of the spur, the PHY clock), R 6 (the balun impedance) having a 75 Ohm impedance and R 7 (representing the CATV load).
[0100] A time domain plot of the spur without the spur cancellation mechanism of the present invention is shown in FIG. 8 . The amplitude of the spur is 1.78 μV=20 log 10 (1.78 μV/0.001 mV)=−55 dBmV. A frequency spectrum of the spur of FIG. 8 is shown in FIG. 9 . The amplitude of the spur is −55 dBmV at 35 MHz.
[0101] A spectrum plot illustrating frequency response of the spur cancellation circuits of FIGS. 5 and 6 is shown in FIG. 7 . The response of the circuit 200 of FIG. 5 (without the spur cancellation mechanism) is measured across resistor R 7 (V_BALUN_OUT_NO_CANCEL) and is shown in trace 220 . The response is relatively flat at −55 dBmV. Dashed line 224 represents the DOCSIS 2.0 specification for spur level (−59 dBmV, see Table 1). Thus, the response of circuit 200 fails to meet the DOCSIS 2.0 specifications.
[0102] A block diagram illustrating a model of a portion of the upstream circuit incorporating the spur cancellation mechanism of the present invention is shown in FIG. 6 . The circuit, generally referenced 210 , comprises SRC 2 (MPEG clock source), coupling capacitor C 3 , spur cancellation circuit 177 , SRC 3 (spur source, PHY clock), R 13 (balun), R 14 (CATV load). The spur cancellation circuit 177 comprises resistors R 8 , R 9 , R 10 , R 11 , R 12 , and capacitors C 4 , C 5 .
[0103] Example values of the resistor and capacitor component values for the circuit 177 are given below in Table 4.
[0000]
TABLE 4
Example component values
Component
Value
R8
100 kOhm
R9
3500 Ohm
R10
100 kOhm
R11
3500 Ohm
R12
3320 Ohm
C4
3.9 pF
C5
3.9 pF
[0104] The value of the coupling capacitor C 3 is 100 nF. Resistor R 13 represents the impedance of the balun which is 75 Ohm while resistor R 14 represents the cable modem load which is 75 Ohm (to maximize power transfer).
[0105] A time domain plot of the spur with the spur cancellation mechanism of the present invention is shown in FIG. 10 . The amplitude of the spur is approximately 34 nV=20 log 10 (34 nV/0.001 mV)=˜−90 dBmV. A frequency spectrum of the spur of FIG. 10 is shown in FIG. 11 . The amplitude of the spur is −95.6 dBmV at 35 MHz, which represents an improvement of approximately 40 dB over the circuit without the spur cancellation circuit.
[0106] Referring to FIG. 7 , the response of the circuit 210 of FIG. 6 (with the spur cancellation mechanism) is measured across resistor R 14 (V_BALUN_OUT_CANCEL) and is shown in trace 222 . The response is a notch with a minimum at −95.5 dBmV which is an improvement of over 40 dBmV compared to the response of circuit 200 ( FIG. 5 ). Thus, the response of circuit 210 meets the DOCSIS 2.0 specifications. Note that the response of FIG. 7 is the results of a simulation. In actuality, the improvement of circuit 210 with the spur cancellation circuit over the circuit 200 without it may be only −15 to −20 dBmV. Thus, the notch minimum would be at approximately −70 dBmV, still well below the maximum level permitted by the DOCSIS 2.0 specification.
Second Embodiment: RF Switch Circuit
[0107] A simplified block diagram illustrating the processor of the cable modem of FIG. 2 including an upstream system incorporating a second embodiment of the spur reduction mechanism of the present invention is shown in FIG. 12 . The example cable modem, generally referenced 150 , comprises diplexer 154 coupled to a CATV input 152 , RF tuner circuit 156 , processor 158 and upstream path circuit 116 .
[0108] The upstream circuit 116 comprises image reject filter 172 , PGA 174 , balun 176 and RF switch 187 . The processor 158 comprises an analog to digital converter (ADC) 160 , PHY circuit 162 , digital to analog converter (DAC) 170 , PGA control circuit 178 , switch control circuit 183 , power supply control 180 and MAC 168 . Power is supplied by an external power source 182 e.g., utility power, etc. or a battery 184 .
[0109] In operation, in the downstream (i.e. receive) direction, the receive signal from the diplexer is input to the CATV RF tuner circuit 156 . The tuner output signal is input to the ADC to provide I and Q input signals to the PHY circuit. The PHY circuit provides a tuner control signal 157 that controls the tuning of the tuner circuit. After MAC processing, one or more MPEG video streams 169 are output of the cable modem.
[0110] In the upstream (US) (i.e. transmit) direction, a digital TX output signal provided by the PHY circuit is converted to analog by the DAC. The analog signal is then filtered via the image reject filter 172 before being amplified by the PGA whose gain is controlled by a PGA control signal 173 generated by the PGA control circuit 178 .
[0111] The output of the PGA circuit is input to one side of the balun 176 . The other side of the balun is input to a single pole double throw (SPDT) RF switch 187 . One terminal of the switch is coupled to the output of the balun while the other terminal is connected to ground via 75 Ohm resistor 189 . The output of the RF switch is input to the diplexer 154 which couples the US signal to the CATV cable 152 .
[0112] In accordance with the invention, the RF switch 187 functions to eliminate in-band spurious emissions from the US signal before input to the diplexer. The second embodiment is based on a wide band isolation RF switch which limits the 35 MHz spur and any additional spurs from leaking to the RF output of the cable modem in between transmission bursts.
[0113] An example RF switch suitable for use with the present invention is the AS211-334, PHEMT GaAs IC SPDT Switch, manufactured by Skyworks, Woburn, Mass., USA. The RF parameters, including linearity, insertion loss and switching performance make this RF switch suitable for use in the example circuit presented herein. It is appreciated that other components with similar parameters may be used.
[0114] In this example circuit, the RF switch is controlled by a switch control signal 185 generated by the switch control circuit 183 internal to the processor 158 . The switch control circuit is operative to couple the output of the balun to the diplexer during transmission bursts and to the resistor coupled to ground in between transmission bursts.
[0115] Note that this second embodiment takes advantage of the relaxed spurious emission levels permitted by the DOCSIS 2.0 during transmission bursts as compared to between bursts (see Tables 1 and 2 presented supra).
[0116] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof
[0117] The corresponding structures, materials, acts, and equivalents of all means or step plus function elements in the claims below are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The description of the present invention has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the invention in the form disclosed. As numerous modifications and changes will readily occur to those skilled in the art, it is intended that the invention not be limited to the limited number of embodiments described herein. Accordingly, it will be appreciated that all suitable variations, modifications and equivalents may be resorted to, falling within the spirit and scope of the present invention. The embodiments were chosen and described in order to best explain the principles of the invention and the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated. | In a novel apparatus for and method of discrete spurious frequency leakage cancellation a radio frequency RF switch is used to couple the upstream path signal to the CATV cable only during transmission bursts. In between transmission bursts, the upstream signal is disconnected from the CATV cable. In a circuit for canceling frequency spurs from a victim signal, a radio frequency (RF) switch is operative to connect and disconnect the victim signal to/from the output in accordance with a switch control signal which is generated by a switch control module. The victim signal is coupled to said RF switch output during transmission bursts only. | 7 |
FIELD OF THE INVENTION
This invention relates to intraocular lenses, and in particular, to accommodating intraocular lenses capable of focusing on objects located at various distances therefrom.
BACKGROUND OF THE INVENTION
The natural lens of a human eye is a transparent crystalline body, which is contained within a capsular bag located behind the iris and in front of the vitreous cavity in a region known as the posterior chamber. The capsular bag is attached on all sides by fibers, called zonules, to a muscular ciliary body. At its rear, the vitreous cavity, which is filled with a gel, further includes the retina, on which light rays passing through the lens are focused. Contraction and relaxation of the ciliary bodies changes the shape of the bag and of the natural lens therein, thereby enabling the eye to focus light rays on the retina originating from objects at various distances.
Cataracts occur when the natural lens of the eye or of its surrounding transparent membrane becomes clouded and obstructs the passage of light resulting in various degrees of blindness. To correct this condition in a patient, a surgical procedure is known to be performed in which the clouded natural lens, or cataract, is extracted and replaced by an artificial intraocular lens. During cataract surgery, the anterior portion of the capsular bag is removed along with the cataract, and the posterior portion of the capsular bag, called the posterior capsule, is sometimes left intact to serve as a support site for implanting the intraocular lens. Such lenses, however, have the drawback that they have a fixed refractive power and are therefore unable to change their focus.
Various types of intraocular lenses having the capability of altering their refractive power have been suggested in an effort to duplicate the performance of the natural lens within the eye. Such accommodating intraocular lenses, as they are known in the art, have a variety of designs directed to enable the patient to focus on, and thereby clearly see, objects located at a plurality of distances. Examples may be found in such publications as U.S. Pat. No. 4,254,509, U.S. Pat. No. 4,932,966, U.S. Pat. No. 6,299,641, and U.S. Pat. No. 6,406,494.
U.S. Pat. No. 5,489,302 discloses an accommodating intraocular lens for implantation in the posterior chamber of the eye. This lens comprises a short tubular rigid frame and transparent and resilient membrane attached thereto at its bases. The frame and the membranes confine a sealed space filled with a gas. The frame includes flexible regions attached via haptics to the posterior capsule. Upon stretching of the capsule by the eye's ciliary muscles, the flexible regions are pulled apart, thereby increasing the volume and decreasing the pressure within the sealed space. This changes the curvature of the membranes and accordingly, the refractive power of the lens.
U.S. Pat. No. 6,117,171 discloses an accommodating intraocular lens which is contained inside an encapsulating rigid shell so as to make it substantially insensitive to changes in the intraocular environment. The lens is adapted to be implanted within the posterior capsule and comprises a flexible transparent membrane, which divides the interior of the intraocular lens into separate front and rear spaces, each filled with a fluid having a different refractive index. The periphery of the rear space is attached to haptics, which are in turn attached to the posterior capsule. Upon stretching of the capsule by the eye's ciliary muscles, the haptics and hence this periphery is twisted apart to increase the volume of rear space and changes the pressure difference between the spaces. As a result, the curvature of the membrane and accordingly, the refractive power of the lens changes.
SUMMARY OF THE INVENTION
The present invention suggests an accommodating lens assembly having an optical axis and being adapted to be implanted in a posterior chamber of an eye having a capsular unit located therein. The assembly comprises a rigid haptics element adapted to secure the assembly within said posterior chamber outside the capsular unit, the element being transparent at least in a region around the axis. The assembly further comprises a resilient body adapted to operate as a lens with a radius of curvature, when pressed up against the region of the rigid element by an axial force applied thereto by the capsular unit, whereby a change in said force causes a change in the radius of curvature.
The term “capsular unit”, as it is used in the present description and claims, refers to the posterior capsule, the zonules, and the ciliary body, which are interconnected and act in unison, forming in accordance with the present invention, a kind of cable whose varying tension provides the axial force applied to and utilized by the lens assembly of the present invention to achieve accommodation.
The assembly of the present invention is directed to substitute for a natural lens after its removal from the eye, not only by enabling the eye to see after implantation of the assembly, but also by enabling it to accommodate and thereby bring into focus objects located at a continuum of distances. In order to achieve the latter, the assembly is designed to be fixed in the posterior chamber, with the resilient body axially abutting the posterior capsule. The resilient body may be attached to the haptic element or may simply be held in place up against the element by the tension of the capsular unit.
The lens assembly of the present invention utilizes the natural compression and relaxation of the capsular unit to impart an axial force on the resilient body in order to cause it to act as a lens whose radius of curvature, and therefore the refractive power it provides, varies depending on the magnitude of the force. In this way, the lens assembly cooperates with the natural operation of the eye to accommodate and enable the eye to clearly see objects at different distances.
The haptics element of the assembly according to the present invention may adopt any of a variety of designs known in the art, e.g. it may be curved or it may be in the form of a plate, which spans a plane essentially perpendicular to the optical axis of the assembly. In addition to the region, the haptics element may be completely transparent. The region of the element may be in the form of a transparent component, such as a clear panel or another lens which may have such a curvature and index of refraction as to enhance the accommodating capability of the lens assembly.
The haptics element may have a hollow space formed in its transparent region. This hollow space is adapted to allow the resilient body to bulge through the space in response to said force. This enables the lens assembly to provide a range of refractive power (i.e. the accommodating capability) depending on the bulge's radius of curvature, which is determined and may be varied by the magnitude of the force applied by the capsular unit.
The haptics element of the lens assembly of the present invention is adapted to securely fix the assembly in front of the capsular unit in the posterior chamber of the eye. It is essential that the haptics element maintain a substantially immovable position. To this end, the haptics element is preferably adapted to be fixed to the scleral wall of the eye in two or more places in the regions between the iris and the ciliary body. To achieve the latter, the haptics element preferably comprise anchoring means, such as in the form of teeth. One example of such means is described in co-pending Israel patent application No. 141529.
Implantation of the lens assembly in accordance with the present invention may be achieved using equipment and techniques that are conventional and well known in the art. However, in order to facilitate the implantation and anchoring of the assembly in the eye, the haptics element of the assembly of the present invention preferably also includes at least one extendible member at its periphery. For example, the haptics element in the form of a plate discussed above may have a telescoping end which is only extended after the assembly has been inserted into the eye and has been positioned at the anchoring site. This extendible member may also be provided with anchoring means attached thereto. The extendible member serves to keep the assembly small enough to insert into the eye until its securing is desired. The extendible member, such as the telescoping end, may be passive or may be spring biased being compressed to enable implantation and released to maintain anchoring by a resisting force.
The haptics element of the lens assembly in accordance with the present invention may be made of a variety of possible rigid materials suitable for invasive medical use and known in the art to be used in the formation of haptics.
The resilient body of the accommodating lens assembly in accordance with the present invention may be made of any suitable deformable material, such as silicone or hydrogel, having an index of refraction different from the gel within the eye. The resilient body must not necessarily be made of a single component or material. For example, the body may be in the form of a sac filled with a fluid or gel. However, in the case of such a sac, for example, it is essential the periphery of the body be made with a unitary material so that the fluctuating internal pressure of the eye does not affect the sac in an anisotropic manner, which would unpredictably affect the vision provided by the assembly.
The resilient body of the accommodating lens assembly in accordance with the present invention may have a variety of shapes so long as the shape has or is able to achieve a radius of curvature and thereby perform as a lens. For example, in the case when the haptics element is curved and solid (i.e. is devoid of a hollow space in said region), the resilient body may have such shapes as a sphere which, when pressed against its haptics element, takes on the shape of a double convex lens. Also, if the haptics element is flat like a plate, for example, the planar side of a hemispherical resilient body may be pressed up against it to act as a plano-convex lens. As another example, if the haptics element is flat and comprises a hollow space, such as an aperture or a cavity, the resilient body having a bi-planar shape, such as that of a solid circular disc, may be pressed up against the element since the force applied by the capsular unit will cause it to bulge into the aperture or cavity and attain, thereby, a radius of curvature.
The accommodating lens assembly in accordance with the present invention may further comprise a rigid piston member, which sandwiches the resilient body between it and the haptics element, and which is designed to be pushed by the force and, in response, to cause the resilient body to take on a desired curved shape. The piston member is transparent at least in a region around the axis and is movable along the axis with respect to the element. One or both of the haptics element and the piston member have a hollow space in their transparent region to allow the resilient body to bulge through the space in response to the force.
The hollow spaces formed in the haptics element and/or the piston member in preferred embodiments of the lens assembly in accordance with the present invention, may have various designs such as circular blind or through holes. Preferable, these spaces are large enough that their periphery is far from the optical axis so as not to substantially affect light passing thereabout by causing diffraction and other such undesired optical effects. Also, in order to minimize such optical disturbances, if a hollow space is formed within the piston member, the haptics element may be devoid of such a space and vice versa.
The piston member of the accommodating lens assembly of the present invention may be made of any of a variety of rigid biocompatible materials. The piston member may also have any of a variety of designs, such as a plano-convex design with the convexly curved side abutting the capsular unit so as to contribute to the range of refractive power which may be achieve by the assembly. Clearly, in the latter case, the transparent region of the piston member, like the resilient body, must have an index of refraction different from the natural gel surrounding the assembly when implanted in the eye. The radius of curvature and the index of refraction of the piston member may be adjusted and chosen in numerous ways to arrive at lens assemblies having various ranges of refractive power and degrees of sensitivity to the force applied by the capsular unit.
The advantages provided by the accommodating lens assembly of the present invention abound, particularly because of it is designed to be positioned in the eye completely outside of the posterior capsule. One advantage, for example, is that the lens assembly does not undesirably stretch and consequently harm the capsule. Also, the lens assembly does not need to conform to the size or shape of the capsule, and is therefore free to take on a larger variety of designs. Furthermore, the capsule is sometimes damaged during the surgery to remove the natural lens, but the lens assembly of the present invention does not require that the capsule be completely intact in the form of a bag but merely that it remain reliably connected as part of the capsular unit. Another advantage arising from the lens assembly being positioned outside of the posterior capsule is that it remains unaffected by the permanent and unpredictable constriction that the capsule inevitably undergoes due to scarring following the surgery for removal of the natural lens.
In addition to the above, the lens assembly of the present invention offers advantages such as a simple and inexpensive construction. The lens assembly of the present invention also provides the ability to accommodate within a vast range of refractive power, including the full range provided by the natural eye. Also, the lens assembly provides means for varying its sensitivity in response to the force applied by the capsular unit.
BRIEF DESCRIPTION OF THE DRAWINGS
In order to understand the invention and to see how it may be carried out in practice, a preferred embodiment will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:
FIG. 1A is a plan view of an accommodating lens assembly in accordance with the present invention;
FIG. 1B is a side view of the accommodating lens assembly shown in FIG. 1A ;
FIG. 2A shows the accommodating lens assembly of FIGS. 1A and 1B as implanted in an eye;
FIG. 2B shows the accommodating lens assembly of FIGS. 1A and 1B in operation after it has been implanted in an eye as in FIG. 2A ;
FIG. 3A is a plan view of another embodiment of an accommodating lens assembly in accordance with the present invention;
FIG. 3B is a side view of the accommodating lens assembly shown in FIG. 3A ;
FIG. 4A shows the accommodating lens assembly of FIGS. 3A and 3B as implanted in an eye;
FIG. 4B shows the accommodating lens assembly of FIGS. 3A and 3B in operation after it has been implanted in an eye as in FIG. 4A ;
FIG. 5A shows yet another embodiment of an accommodating lens assembly in accordance with the present invention as implanted in the eye;
FIG. 5B shows the accommodating lens assembly of FIG. 5A in operation in the eye.
DETAILED DESCRIPTION OF THE INVENTION
The subsequent description and figures refer to different examples of an accommodating lens assembly of the present invention and its functional position as implanted in a human eye E. As shown in FIGS. 2A , 2 B, 4 A, 4 B, 5 A, and 5 B, the eye E, which is filled with natural gel (not shown) having an index of refraction of about 1.3, comprises a scleral wall S, an iris, and a retina R (not shown). The eye E further includes a ciliary body CB, from which extend zonules Z connected to a posterior capsule PC. These last three parts of the eye E constitute the capsular unit 1 .
One example of an accommodating lens assembly in accordance with the present invention adapted for implantation within the eye E is shown in FIG. 1A in plan view and in FIG. 1B from a side view. The accommodating lens assembly 2 has an optical axis A—A and comprises a rigid haptics plate 4 having a first lens 6 made of a rigid material having an index of refraction higher than that of water. The plate 4 further includes a telescoping haptics member 8 , which is slidably biased in grooves 8 a so as to be extendible in a plane perpendicular to the optical axis A—A. The plate 4 and the telescoping member 8 have teeth 9 projecting therefrom for anchoring the first lens assembly 2 within the eye E.
The lens assembly 2 further comprises a silicone ball 10 attached to the plate 4 so as to be located on the axis A—A. The silicone ball 10 also has an index of refraction higher than that of water.
As is shown in FIGS. 2A and 2B , the haptics plate 4 of the assembly 2 is anchored, using the teeth 9 , to the eye's scleral wall S at two locations between the ciliary body CB and the iris I. The anchoring is done by first inserting the teeth 9 on the plate 4 to the desired point in the scleral wall S, and then extending the telescoping member 8 until its teeth 9 enter the opposing side of the scleral wall S. The silicone ball 10 directly contacts the capsular unit 1 , which is stretched around the ball 10 and transforms it into a second piano-convex lens 10 ′ as shown in FIG. 2A with a radius of curvature R 1 .
In operation, upon contraction and relaxation by muscles of the ciliary body CV, tension in the capsular unit 1 will change and a variable force proportional to the tension will be applied to the silicone ball 10 along axis A—A. FIG. 2B shows an increase in tension in the capsular unit 1 compared to FIG. 2A upon relaxation of the ciliary body CB. The increase in tension applies a forward force along the axis in the direction of the iris I. This force causes the lens 10 ′ to further deform and increase its radius of curvature from R 1 to R 2 . This increase in radius will enable the eye E to focus on far objects by adjusting the assembly's focal plane until it resides on the retina. Clearly, the reverse may be done in which the ciliary body contracts, reducing the radius to focus on objects at near distances from the eye E.
Another example of an accommodating lens assembly 22 for implantation within a human eye E in accordance with the present invention is shown in a preferred embodiment in FIG. 3A in plan view and in FIG. 3B from a side view.
The accommodating lens assembly 22 has an optical axis B—B and comprises a rigid haptics plate 24 , similar to that included in the lens assembly 2 , and having a circular aperture 26 . The plate 24 further includes a telescoping member 28 , which is slidably biased in grooves 28 a so as to be extendible. The plate 24 and the telescoping member 28 have teeth 29 projecting therefrom for anchoring the lens assembly 22 within the eye. The plate further includes a hollow, central cylindrical tube portion T extending around axis B—B. The tube portion T is concentric with the aperture 26 but has about double the diameter.
The accommodating lens assembly 22 further comprises a silicone disc 30 received within the tube portion T so as to occupy only a part of its axial dimension. The disc 30 has an index of refraction higher than that of water.
The lens assembly 22 also includes a rigid, plano convex lens 31 having a diameter slightly smaller than that of the tube portion T but greater than that of the aperture 26 . The lens 31 , which is designed to function like a piston by transferring an applied force to the disc 30 , is received within the tube portion T to fill the space left unoccupied by the disc 30 and to press, with its planar face, the disc 30 up against the plate 24 . The plano-convex lens 31 has a fixed radius of curvature and an index of refraction higher than that of water.
FIGS. 4A and 4B show the haptics plate 24 of the assembly 22 anchored, using the teeth 29 , to the eye's scleral wall S at two locations, each being between the ciliary body CB and the iris I. The silicone disc 30 is sandwiched between the haptics plate 24 and the lens 31 , which directly contacts the capsular unit 1 with its convex side.
In operation, upon contraction and relaxation by muscles of the ciliary body CB, tension in the capsular unit 1 will change and apply a force to the lens 31 along axis B—B. FIG. 4B shows an increase in tension in the capsular unit 1 compared to FIG. 4A , which occurs upon relaxation of the ciliary body CB. This increase in tension applies a forward force on the lens 31 along the axis in the direction of the iris I. The applied force pushes the lens 31 , which functions like a piston and presses, in turn, on the silicone disc 30 , causing it to protrude from the aperture 26 in the form of a bulge 35 having a radius of curvature depending on the force. The bulge 35 serves to add to the refractive power afforded by the convex curvature of lens 31 . In this way, using the lens assembly 22 , the eye E is given the ability to focus on nearer objects by changing the magnitude of the applied force and hence the radius of the bulge 35 until the object is focused on the retina R.
Yet another example of a lens assembly 42 in accordance with the present invention for implantation into the eye E is shown in a preferred embodiment in FIGS. 5A and 5B . The lens assembly 42 is similar to the lens assembly 22 in that it comprises a haptics plate 44 with an aperture which is occupied by a rigid lens 46 , similarly to lens 6 in FIG. 1A . Furthermore, the lens assembly 42 comprises a piston member 51 . However, the piston member 51 has a cylindrical cavity 52 formed therein, into the silicone disc 50 is adapted to bulge. The member 51 is adapted transfer an axial force applied by the capsular unit 1 to silicone disc 50 sandwiched between the member 51 and the plate 44 . In this way, the piston member 51 is similar to plano-convex lens 31 shown e.g. in FIG. 4A , but differs in that it does not have the additional ability to operate as a lens.
In operation, the piston member 51 of the lens assembly 42 transfers the axial force, created thereon by changes of tension in the capsular unit 1 , to the silicone disc 50 , causing it to form a bulge 54 , which protrudes back into the cavity 52 . The bulge 54 has a radius of curvature whose value varies depending on the magnitude of the force. As in the previously described embodiment, the bulge 54 serves to provide the assembly 42 with a refractive power, whose magnitude can be varied by the force applied by the capsular unit 1 and controlled by the contraction and relaxation of muscles in the eye's ciliary body CB.
It should be understood that the above described embodiments constitute only examples of an accommodating lens assembly for implantation into the eye according to the present invention, and that the scope of the present invention fully encompasses other embodiments which may become obvious to those skilled in the art. For example, while implantation of the lens assembly in humans is described, the assembly may clearly also be applicable to other animals. Clearly, any and all possible permutations and/or combinations of different features as described above are within the scope of the present invention. | An accommodating lens assembly having an optical axis and being adapted to be implanted in a posterior chamber of an eye having a capsular unit located therein. The assembly includes a rigid haptics element adapted to secure the assembly within the posterior chamber outside said capsular unit. The element is transparent at least in a region around the axis. The assembly further includes a resilient body adapted to operate as a lens having a curved surface when pressed up against the region of the haptics element by an axial force applied thereto by the capsular unit. A change in this force causes a change in a radius of curvature for the curved surface. | 0 |
BACKGROUND OF THE INVENTION
U.S. patent application of Ser. No. 06/365,833 filed by the present inventor on Apr. 5, 1982 was allowed on June 23, 1983, which still has the defect to require a pivotting means to pivotedly fix a float-actuated control lever on the pivotting means whereby the installation of such a flushing controller on a toilet tank will become difficult for a user especially for a housewife and the production cost will also be increased.
The present inventor has found this defect and invented the present improved flushing controller for a toilet.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a flushing controller for toilet which comprises a variable flushing actuator, a pre-set flushing actuator, a fixed bushing and a vertically adjusted float so that the float can be freely adjusted to control the volume of flushing water for saving water resource when operating the pre-set flushing actuator for flushing stools.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top-view sectional drawing of the present invention.
FIG. 2 is a front-view sectional drawing of the present invention.
FIG. 3 is an illustration of another preferred embodiment of the present invention.
DETAILED DESCRIPTION
As shown in FIGS. 1 and 2, the present invention comprises: a variable flushing actuator 1, a pre-set flushing actuator 2, a fixed bushing 3 and a vertically-adjusted float 4.
Variable flushing actuator 1 comprises a handle 11, a spindle 12 connected with handle 11, and a lever 13 connected with toilet flush valve by a wire 14. Handle 11 is centrally formed with a circular hole 11a and fit with a flat plate 11b. Spindle 12 is terminated by a threaded portion 11d which is formed with a groove 11e to engage with flat plate 11b of handle 11 and is then capped by a knob 11c. The length of wire 14 is designed so that when the acutators 1,2 are depressed to straightly pull the wire, the flush valve can be fully opened.
Pre-set flushing actuator 2 comprises: a handle 21, a spindle 22, a float engaging means 23, an extension ring 24 formed on the rear end of engaging means 23 and rotatably fixed in fixed bushing 3, a bushing cover 25 rotatably sealing hollow cylinder 31 of bushing bush 3 and a rest plate 26 extending from cover 25 to biase lever 13 when depressing handle 21. Handle 21 is centrally formed with a square hole 21a for fixing the square head 22a of spindle 22.
A lengthy hole 22' is centrally formed inside spindle 22 for freely inserting spindle 12 of variable flushing actuator 1. Float engaging means 23 is formed on the rear portion of pre-set flushing actuator 2 which is formed with three upper extensions 23a and a lower extension 23b respectively extending from the central spindle 22, each extension being separated in equal radians. The lower extension 23b formed on the lowest portion is cut with a recess to engage with the float lever 43 as FIG. 2 shown.
Fixed bushing 3 comprises a hollow cylinder 31 for rotatably fixing spindles 12, 22. An extension 32 is formed on the front portion of cylinder 31 and is formed with a threaded portion 33 whereby the present invention can be fixed on tank wall w by means of nut 34, packing 32b, packing 34a, and washer 34b. The bushing 3 is formed with a central hole 32a for passing spindle 22. A guide block 35 is formed on the lower portion of bushing 3, which is centrally provided with a hollow pipe 35a for reciprocative motion of a float lever 43 having a lever head 44. Such pipe 35a is cut with a slot 35b for inserting a pin 35c therein to limit the movement of lever head 44 by the neck portion 44b. The lever head 44 is formed with a tapered portion 44a on its top end to engage with recess 23b of float engaging means 23. Three grooves 31b are formed inside cylinder 31 to limit the rotation of extensions 23a formed on float engaging means 23.
Vertically adjusted float 4 comprises a hollow cylinder 41 which is partitioned traversely by a diaphragm plate 41a to form an upper chamber 4a and a lower chamber 4b and is centrally longitudinally formed with a central jacket tube 42 for free adjustment of float lever 43 which is freely jacketed in tube 42 and can be fixed on jacket tube 42 by fastening a belt 42c on groove 42b.
Whenever using the present invention, the variable flushing actuator 1 may be actuated to suitably open the toilet flush valve for small volume flushing such as urine. If for larger flushing such as for stools, the pre-set flushing actuator 2 is actuated to open the toilet flush valve and once the handle 21 is depressed, the float engaging means 23 will be rotated in direction R as shown in FIG. 2 and the recess 23b will be engaged with float lever 43 so that the buoyancy of float 4 will lock the pre-set flushing actuator 2 to open the toilet valve until the water lever drops under the float 4 whereby the float weight will voluntarily fall to unlock the flushing actuator 2 so as to close the flush valve and the water is refilled into toilet tank for next use. The float 4 may be freely adjusted along the lever 43 to save water resource. For example, the higher the float is, less water will be drained when opening toilet valve. Naturally, when adjusting the float height, the minimum water required for efficiently cleaning toilet bowl should be considered. In the present invention, the upper chamber 4a of float 4 serves as weight as filled water for quicker drop when not backed by water buoyancy. The lower chamber 4b accumulated with air naturally becomes a float. Both chambers are not covered.
The float 4 of the present invention may be made as a closed hollow cylinder and the lever 43 be made in a heavier diameter or in larger weight so as to facilitate the drop of float when bearing no water buoyancy.
The present invention has the following advantages superior to conventional toilets:
1. The constructed parts are simple for easier installation either for new toilet or for renewing the old toilet.
2. The production cost can be greatly reduced for wider applications.
3. Maintenance problems will be reduced as minimum as possible as the simple construction thereof. | A flushing controller for a toilet which includes a variable flushing actuator, a pre-set flushing actuator, a fixed bush and a vertically adjusted float wherein the float can be freely and continuously adjusted for saving water resources when operating the pre-set flushing actuator. | 4 |
FIELD OF THE INVENTION
The present invention generally relates to an apparatus and a method for measuring the remaining capacity of a storage battery, and more specifically, to an apparatus and a method for measuring the current drawn by a load applied to the storage battery over time to determine the power consumed by the load.
BACKGROUND OF THE INVENTION
The electrical power rating of a storage battery is defined in terms of the electrical current that can be discharged from the battery into a load over time at the rated voltage. Typically, a battery is employed to energize a device when a line electrical power source is either unavailable or the cost/space limitations of the device make the use of a line source undesirable. Since the amount of electrical power that can be stored by a storage battery is finite, it is highly desirable to provide means for accurately measuring the power discharged from a battery supplying electrical current to a device.
One of the simplest circuits for measuring current supplied by a battery to a load employs a low resistance "sense" resistor connected in series between the load and a terminal of the battery. The voltage across the sense resistor is indicative of the current flowing to the load from the storage battery. The circuit measures the magnitude of this voltage and provides a corresponding load current indication. However, this simple circuit does not measure the total amount of current from the battery over a period of time. Instead, only the instantaneous flow of current through the load is determined. Additional circuitry must be provided to determine the total power discharged from the battery. A digital processor is particularly well suited to the task of determining the total electrical power discharged from the battery and determining the remaining power stored therein. Since instantaneous current measurements are indicated by an analog signal, an analog-to-digital (A/D) conversion is required to enable a digital processor to use the signal indicative of current. An A/D converter can be used to transform the analog signal into a digital value, which is scaled to the number of digital bits provided by the A/D converter, e.g., an 8-bit A/D converter provides a digital value scaled from 0 to 255.
Another device that can be employed to perform A/D conversion is a comparator, which produces a digital bit when an analog signal at one input is equal to or greater than a reference signal at another input. Typically, the reference signal has a ramp waveform with a time period that is predetermined by the digital processor, so that the comparator produces a digital bit at the "cross over" point, e.g., when the value of the ramping reference signal is equal to or greater than the analog signal. The processor employs the time period of the "cross over" point and the time period of the ramp to determine an approximation of the total amount of current that was discharged from the battery. Since the comparator can only produce a single bit at the cross over point, the approximation is only accurate if the ramp waveform time period is at least twice as fast as the changes occurring in the measured signal. Thus, if the signal being measured is a discontinuous analog signal that switches on and off twice as fast as the ramp's time period, then the processor will fail to detect the current signal to be measured.
Until recently, devices having discontinuous current draw occurring during time intervals significantly shorter than the sampling period of a digital processor were relatively unknown. However, a substantial increase in the use of devices such as stepper motors, which intermittently draw current for time periods that are significantly shorter than the sampling rate of most digital processors, has made it difficult to accurately measure short-term discontinuous load currents. Stepper motors are often employed in battery powered consumer electronic devices, such as video camcorders and portable compact disc (CD) players. Also, the medical industry employs stepper motors to drive medical pumps that deliver specific quantities of medical substances to patients. Accordingly, it will be apparent that there is a need for a low cost approach for monitoring the current supplied to such devices over time to determine the charge remaining on storage batteries used to energize the devices.
SUMMARY OF THE INVENTION
A preferred embodiment of the invention incorporates the electronic circuit generally described above for measuring the voltage drop across a sense resistor and converting the voltage drop signal into a digitized value with an A/D converter that is coupled to a digital processor. However, the solution provided by the present invention employs an analog integration circuit for accumulating short term changes in the voltage across the sense resistor during a predetermined time interval. The integration circuit sums the plurality of short term pulses of current flowing to the load over a time interval so that all of the current flowing to the load that is coupled to a battery can be considered in determining the total electrical power discharged from a battery.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same becomes better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:
FIG. 1 is an electrical schematic diagram of a preferred embodiment of a battery management system in accord with the present invention;
FIG. 2 is a timing diagram that illustrates the correspondence between the electrical current being measured and a pair of digital signals produced by a central processing unit (CPU) in the device energized by the battery; and
FIG. 3 is a functional block diagram showing an overview of the battery management system.
DESCRIPTION OF THE PREFERRED EMBODIMENT
As noted above, an object of the present invention is to provide a battery capacity measurement circuit for measuring discontinuous current pulses drawn by a load that occur intermittently for extremely brief periods of time. The time periods of the pulses are so short that it is necessary to sum (integrate) a voltage signal indicative of the magnitude of the current pulses over a fixed period of time, so that a central processing unit (CPU) can accurately determine the value of the summed signal and thus, the charge remaining in the battery.
A precision battery capacity measurement circuit 100, which achieves this object, is shown in FIG. 1. With reference to FIG. 1, a battery 102 has a negative terminal that is coupled to the drain terminal of an enhancement mode n-channel metal oxide semiconductor field effect transistor (MOSFET) 106. A sense resistor 110 has one end connected to the common ground of the circuit and its other end coupled to the source terminal of MOSFET 106. The gate of MOSFET 106 is coupled to one end of a resistor 108, and the other end of the resistor is coupled to the OUT1 port of a central processing unit (CPU) 132. When the CPU applies a charge (CHG) signal of about five volts from the OUT1 port to the gate of MOSFET 106 through resistor 108, the MOSFET starts to conduct and then provides a current path from its drain to its source, i.e., from the negative terminal of battery 102 to the common ground. CPU 132 is preferably a microcontroller that includes both random access memory (RAM) and read only memory (ROM). One or more programs that control the operation of CPU 132 are stored in the ROM, and the RAM stores data for processing by the CPU.
MOSFET 106 is a power semiconductor device, which has its body connected internally to the source terminal. The internal connection effectively forms a diode 107 that has an anode connected to the source terminal of MOSFET 106 and a cathode connected to the drain terminal. Further, diode 107 will conduct when the source-drain voltage is positive and greater than the diode's rated voltage drop, i.e., a return path for current is provided by the diode from the common ground to the negative terminal of battery 102 when the voltage at the negative terminal of battery 102 is substantially less than the common ground voltage. Moreover, a positive source-drain voltage occurs when battery 102 is the sole source of current to energize circuit 100 (battery mode). In the battery mode, circuit 100 measures a negative voltage drop across sense resistor 110 from the negative terminal of the battery to the common ground, so that the total amount of current drawn from the battery by a load coupled to the circuit may be determined.
An AC line source supplies an AC voltage to an AC/DC supply 134 that rectifies the AC voltage, producing a corresponding DC voltage signal. The output terminal of AC/DC supply 134 is coupled to the anode of a diode 136. The cathode of diode 136 is coupled to an input of a DC voltage regulator 180, which produces a VCC signal (+5 volts) that is supplied to specific components in circuit 100 and to other load components in the device that are not shown. Also, the cathode of diode 136 is coupled to the positive terminal of battery 102. Consequently, the voltage applied to the positive terminal of battery 102 is equal to the magnitude of the DC voltage signal rectified by AC/DC supply 134, minus the voltage drop across diode 136.
In the preferred embodiment, battery 102 is rated for six volts, and supply 134 produces a DC signal of about 7.5 volts that is reduced to a 6.8 volt signal at the positive terminal of the battery by the voltage drop across diode 136. An AC line source is employed to energize AC/DC supply 134 (line mode), so that a DC voltage is provided for recharging battery 102 and for energizing a load and circuit 100. In the line mode of operation, the common ground provided by AC/DC supply 134 is at a lower voltage than the negative terminal of battery 102 during recharging, and a current will flow from the negative terminal to the common ground so long as MOSFET 106 is conducting. Further, when operating in the line mode, circuit 100 will measure a positive voltage drop across sense resistor 110 from the negative terminal of the battery to the common ground, so that the total amount of current drawn by the battery during recharging may be determined. Additionally, when CPU 132 lowers the magnitude of the CHG signal at the OUT1 port to zero volts, MOSFET 106 stops conducting, and the current path from the negative terminal of battery 102 to the common ground of AC/DC supply 134 through sense resistor 110 is interrupted. In this manner, CPU 132 employs MOSFET 106 to stop and start the flow through sense resistor 110 of a current that is provided by AC/DC supply 134 to recharge battery 102.
The disposition of diode 136 is important to the operation of circuit 100 for at least two reasons. First, the voltage drop across the diode limits the magnitude of the voltage applied to recharge the battery. Second, when the DC signal from AC/DC supply 134 is not present, diode 136 blocks reverse current flow into the AC/DC supply from battery 102.
Additionally, a resistor 176 has one end coupled to the anode of diode 136 and its other end coupled to an IN1 port of CPU 132. A resistor 178 is connected in series with resistor 176 to the common ground, producing a voltage divider that reduces the voltage level from that provided by AC/DC supply 134. An active high ACON signal (+5 volts) is applied to the IN1 port from the common junction of resistors 176 and 178 when AC/DC supply 134 is energized, and a low (zero volts) ACON signal is applied to the IN1 port when the AC/DC supply is not energized. Based upon the level of the ACON signal, CPU 132 determines when AC/DC supply 134 is supplying the electrical current for energizing circuit 100 and the load. Moreover, since the negative terminal of battery 102 is coupled to the common ground through the parallel connection of MOSFET 106 and diode 107, the electrical components of circuit 100 cannot be reliably isolated for calibration when the circuit is being solely energized by the battery. Thus, MOSFET 106 is only switched to a non-conductive state when circuit 100 is in the line mode of operation.
A resistor 114 has one end connected to the common junction of the source terminal of MOSFET 106 and the end of resistor 110; the other end of resistor 114 is coupled to the inverting input of an operational amplifier (opamp) 120. A resistor 112 is connected between VCC (+5 volts) and the inverting input of opamp 120. In addition, a resistor 116 is connected in series with a resistor 118 between VCC and the common ground of the circuit forming another voltage divider. The common junction of resistors 116 and 118 is coupled to the non-inverting input of opamp 120. Resistors 112, 114, 116, and 118 are precision resistors having resistance values that are carefully chosen to bias the output of opamp 120 to a predetermined level greater than zero volts under the conditions described below.
Significantly, whenever battery 102 is being recharged by AC/DC supply 134, the voltage drop across sense resistor 110 from the negative terminal to the common ground is positive. This positive voltage drop across the sense resistor, when applied to the inverting input of opamp 120, would tend to produce a negative voltage at the output of opamp 120 if the non-inverting input of the opamp were referenced to the common ground. To prevent opamp 120 from having to output a negative voltage when battery 102 is being recharged, the values of the biasing resistors (112, 114, 116, and 118) are selected to ensure that the opamp's output will always be equal to or greater than zero volts for the maximum possible recharge current passing through sense resistor 110. In the preferred embodiment, the maximum recharge current through sense resistor 110 was determined to be -1.0 amps, and the biased output of opamp 120 was set at 0.7 volts for zero current flowing through the sense resistor. Thus, the biasing resistors eliminate the need to provide a negative voltage supply to opamp 120, and a negative voltage (less than zero volts) does not need to be produced by the opamp when the maximum charge current (-1.0 amp) passes through sense resistor 110 (i.e., when the AC/DC supply 134 is recharging battery 102).
A capacitor 122 is connected between the inverting input and the output of opamp 120, so that the opamp will function as an electronic integrator. Over a period of time, the electrical charge accumulated in capacitor 122 will correspond to the sum of the magnitudes of the current pulses applied to the input of the opamp, as a function of the voltage drop across sense resistor 110. The accumulated electrical charge in capacitor 122 causes a corresponding voltage at the output of the opamp, until capacitor 122 is discharged.
An electronic switch 128 is coupled in parallel with capacitor 122, and the switch is controlled by an Integrator Reset (INTRST) signal that is supplied from an OUT2 port of CPU 132. At the beginning of a periodic and predetermined time interval (100 milliseconds in the preferred embodiment), the INTRST signal is set to active high (about +5 volts) for a shorter predetermined time period (100 microseconds in the preferred embodiment). When the INTRST signal is active high, electronic switch 128 conducts, and capacitor 122 is discharged so that the output of opamp 120 is reset to a no load reference value. After the predetermined shorter time period has elapsed, the magnitude of the INTRST signal is set low (zero volts), and electronic switch 128 "opens," enabling electrical charge to begin accumulating in capacitor 122 for the remainder of the predetermined time interval (approximately 100 milliseconds).
A resistor 124 is coupled between the output of opamp 120 and the input of an A/D converter 130, and a capacitor 126 is connected between the common ground and the input of A/D converter 130. Resistor 124 and capacitor 126 thus form a single pole, low pass filter. Further, the values of resistor 124 and capacitor 126 are selected so that this filter will suppress any transient signals (noise) having a frequency greater than expected in the voltage signal produced by opamp 120. The filtered output signal (VINTA) is presented at the input to A/D converter 130 and digitized, providing a digital (VINT) signal having a scaled value. In the preferred embodiment, A/D converter 130 provides a single byte digital signal having a positive value that is scaled linearly from 0 to 255, corresponding to a filtered VINTA signal ranging from zero to +five volts. The output of A/D converter 130 is coupled to an IN2 port of CPU 132, enabling the VINT signal to be sampled at the end of the predetermined time interval and processed by a program stored within the CPU. The program implements a variety of functions that are employed in the management of battery 102, including recharging the battery, calibrating the circuitry, and measuring current flow to a load over time to determine the power remaining in the battery.
Further, circuit 100 provides for measuring current flowing through a plurality of loads having different voltage requirements. A load2 174 that is preferably energized by a conditioned five volt DC signal (VCC) is preferably coupled to the output of DC voltage regulator 180. However, a load1 104, such as a stepper motor that operates efficiently at a higher voltage/unregulated voltage, is preferably connected to the positive terminal of battery 102.
Looking now to FIG. 2, a timing diagram illustrates the correspondence between four signals, VINTA, INTRST, IBATT and CHG, which are employed to calibrate circuit 100 during the line mode of operation. A calibration sequence for the output of circuit 100 is shown, extending over ten time periods that are each 100 milliseconds in duration. In the Figure, the filtered VINTA signal is illustrated relative to time, which extends along an x-axis 140. Starting at the left hand side of x-axis 140 (time=0), the VINTA signals in the first and second time periods are represented by a measurement waveform 142 that has a negative ramp shape, which decreases in magnitude from left to right.
Also, the first 100 microseconds of every time period along x-axis 140 are represented by a zero reference waveform 138, which has a magnitude proportional to the no load reference value produced by opamp 120 when electronic switch 128 is conducting.
The INTRST signal is shown relative to time, extending along an x-axis 156 from left to right. For each time period along x-axis 156, the INTRST signal includes a pulse or a step waveform 158 (logic level one high) during the first 100 microseconds and then drops to a low waveform 160 (logic level zero low) for the remainder of the period. The magnitude of the VINTA signal is cleared and set to zero reference waveform 138 when the INTRST signal is logically high, as graphically represented by step waveform 158.
CPU 132 samples the digitized value (VINT) of the magnitude of the VINTA signal at the end of each time period and before the value stored by the electronic integrator is cleared and reset to the no load reference value by the INTRST signal. Each sampled value of the VINT signal is accumulated by CPU 132 so that the program can determine the total amount of current drawn through sense resistor 110 over time, and thus the total amount of power consumed by a load. The CHG signal relative to time is illustrated along an x-axis 162 that extends from left to right, as a step waveform 164 (logic level one high), during the first and second time periods.
Discontinuous current pulses (IBATT) drawn by a load coupled to circuit 100 are represented relative to time by a series of step waveforms 182 extending along an x-axis 184. In the line mode of operation, the accumulated value of the current pulses illustrated for the first and second time periods correspond to the magnitude of the VINTA signal at the end of each time period. The magnitudes of the VINTA signals are directly proportional to the amount of current flowing from the negative terminal of battery 102 to the common ground over time, i.e., the current provided by AC/DC supply 134 to recharge battery 102. In contrast, the accumulated values of the pulses measured by circuit 100 when operating in the battery mode correspond to the magnitude of the VINTA signals, which are proportional to the current flowing from battery 102 to energize a load coupled to the circuit.
Referring back to the top graph in FIG. 2, the filtered VINTA signal becomes a settling waveform 144 that has a negative ramp shape, which decreases over time along x-axis 140. At the start of the third period in the bottom graph in this Figure, the CHG signal decreases, having a falling edge 166 that transitions from the logic level one high to a logic level zero low, as represented by a low waveform 168. The logic level of the CHG signal remains low until the end of the seventh time period. Once the CHG signal has a logic level zero low state, MOSFET 106 stops conducting, and the flow of current through sense resistor 110 is interrupted. However, MOSFET 106 does not instantaneously stop conducting and the slew rate of the MOSFET causes a delay in the interruption of the current flow through the sense resistor. The MOSFET device employed in the preferred embodiment has a slew rate that is considerably less than the predetermined time interval (100 milliseconds), so that the VINTA signal is stable by the end of the third time period. Although the value of the digitized VINTA signal (VINT) is sampled by CPU 132 at the end of the third time period and added to the accumulated value of current drawn by the load over time, the sampled value is not employed to calibrate circuit 100.
In the fourth time period, the VINTA signal is a ramp waveform 146 having a slightly increasing incline from left to right. Since the VINTA signal is now stable, CPU 132 samples the digitized magnitude of the VINTA signal at the end of the fourth period. The sampled VINTA signal corresponds to a zero current offset value 147. The sampling sequence is repeated again for the fifth, sixth, and seventh time periods, enabling CPU 132 to accumulate three more zero current offset values 149, 151, and 153 for ramp waveforms 148, 150, and 152, at the end of each respective time period.
In the preferred embodiment, the four zero current offset values accumulated by CPU 132 are used to measure the leakage current flowing through the electronic components to discharge capacitor 122. Each zero current offset value corresponds to the amount of voltage that is develops in circuit 100 due to the leakage current when the voltage drop across sense resistor 110 is approximately equal to zero volts. Furthermore, the program averages the digitized values of the zero current offset value to calibrate a new zero current offset value for the VINT signal. Averaging is employed to minimize the effect of any transients that may be present in one or more of the zero current offset values and thereby improve the accuracy with which the zero current offset value of circuit 100 is determined.
In the eighth time period, the VINTA signal is a rising waveform 154 that has a negative ramp shape, which decreases from left to right. At the beginning of the eighth time period, the CHG signal is a rising edge 170 that transitions to a step waveform 172 (logic level one high). The CHG signal remains high for the ninth and tenth time periods. When the CHG signal is logically high, MOSFET 106 starts conducting, and the current again flows through sense resistor 110. CPU 132 samples the VINT signal at the end of the eighth time period and adds the sampled value to the accumulated value of current drawn by the load.
Moving across FIG. 2 to the ninth and tenth time periods in the top graph, the negative peak VINTA signal values shown on x-axis 140 for these time periods are digitized and sampled by CPU 132. The program employs the new zero current offset value to determine the actual value of the VINT signals sampled for the ninth and tenth periods. Since the calibration sequence for determining a new zero current offset value is preferably performed every 15 minutes in the line mode, the program can automatically compensate for increases in operating temperature and/or changes in electronic component leakage currents. However, circuit 100 does not reliably measure leakage currents when the circuit is solely energized by battery 102. Consequently, the last determined "new" zero current offset value is employed by CPU 132 to measure the load current whenever circuit 100 is not in the line mode of operation.
In the battery mode of operation, circuit 100 measures the amount of current provided by battery 102 to energize a load every 100 milliseconds, and the program stored within CPU 132 employs the last determined zero current offset value to accurately determine the current for each successive time period when accumulating the total amount of current drawn by the load from battery 102 over time. The current provided by battery 102 is determined by accumulating the difference between the magnitude of the VINT signal and the zero current offset value for each predetermined time period. As discussed above, the last determined zero current offset value is employed by the program until circuit 100 is switched back to the line mode of operation and another zero current offset value is evaluated.
The functional steps necessary to implement the claimed invention have been expressed in sufficient detail in the preceding discussion to enable a person of ordinary skill in the art to write a program that follows the sequence of steps required to practice the present invention without undue experimentation. Accordingly, an enabling disclosure of the software steps in the program implemented by the present invention has been disclosed, and a detailed listing or flow chart of the program is not required.
Turning now to FIG. 3, a functional block diagram identifies the major components of a battery management system 200 that embodies the present invention. An AC line source 206 supplies electrical power to a charge circuit 204 that is coupled to a battery 102. A measurement circuit 202 (i.e., all of the components of circuit 100 except CPU 132 and battery 102) is coupled to battery 102 to measure the current flowing from the battery over time and thus determine the charge remaining in the battery. If the charge (power) remaining stored in the battery is less than a predetermined limit, the user will be alerted, e.g., with a flashing alarm light or audible signal (neither shown), to recharge the battery. The charge and measurement circuits are coupled to CPU 132, which executes the software program to control and coordinate the various battery management circuits. Once the program determines that the battery has been sufficiently discharged, the charge circuit is automatically employed to replenish the charge stored within the battery, assuming the AC/DC supply is connected to the line power source.
In the preferred embodiment, battery 102 is a lead acid type. Other types of rechargeable and non-rechargeable batteries could alternatively be used, including nickel hydride, lithium ion, and nickel cadmium. In an alternative embodiment in which a non-rechargeable battery is employed, the program would not use charge circuit 204 to charge the battery. Instead, the program would only employ measurement circuit 202 to monitor the power (current) supplied by battery 102.
It is also envisioned that further alternative embodiments might employ a bipolar junction transistor (BJT) or a junction field effect transistor (JFET) to perform substantially the same function as MOSFET 106. Additionally, in an alternative embodiment, it might be desirable to connect a plurality of electronic switches in parallel with capacitor 122 across the input and output of opamp 120. Since the total resistance of the electronic switch is reduced by paralleling multiple switches, the RC time constant for resetting the output of opamp 120 to a low level waveform that represents a zero reference value would be significantly reduced compared to the 100 microseconds time period of the embodiment discussed above.
Although the present invention has been described in connection with the preferred form of practicing it and modifications thereto, those of ordinary skill in the art will understand that many other modifications can be made to the invention within the scope of the claims that follow. Accordingly, it is not intended that the scope of the invention in any way be limited by the above description, but instead be determined entirely by reference to the claims that follow. | An electronic circuit and a method for accurately measuring intermittent current pulses supplied by a storage battery to energize a load. In the preferred embodiment, an analog integrator accumulates current pulses in response to a voltage drop across a sense resistor that is connected in series between the storage battery and the load. The voltage drop is proportional to the flow of current from the battery through the load. The output of the integrator is filtered with a low pass filter to block high frequency noise, and the output of the filter is coupled to an analog to digital (A/D) converter that transforms the filtered analog signal into a corresponding digital signal. The output of the A/D converter is supplied to a port of a processor. The processor provides a signal to actuate a reset switch coupled across the integrator. When closed at the end of each integration time period, this switch zeroes the output of the analog integrator. Additionally, the processor recalibrates the circuit at predefined time intervals to determine for leakage currents for improving the accuracy with which the measurement of the flow of current from the battery is determined. In the preferred embodiment, the processor samples the output of the A/D converter every 100 milliseconds. Typically, the calibration procedure is performed every 15 minutes (while the load is energized from an AC source). This measurement circuit is part of a battery management system that preferably also includes a charge circuit for recharging the battery. | 8 |
[0001] This patent is a continuation in part of “An Implantable Biodegradable Wound Closure Device and Method”, filed on Apr. 11, 2010 as U.S. application Ser. No. 12/758,027 and issued as U.S. Pat. No. 8,506,593 on Aug. 13, 2013. It is also a continuation in part of “Implantable Biodegradable Wound Closure Device and Method”, filed on May 20, 2012 as U.S. application Ser. No. 13/475,996. It is also a continuation of “Implantable Tissue Scaffold and Method”, filed on Mar. 14, 2013, as U.S. application Ser. No. 61/786,276.
BACKGROUND OF THE INVENTION
[0002] Field of the Invention
[0003] The present invention generally relates to a trocar defect closure device that is used either directly by a surgical team or indirectly as an attachment to a robotics controller to repair the defect typically left in the fascia layer during laparoscopic surgery by an instrument called a trocar.
[0004] Laparoscopic surgery was introduced as an alternative to open surgical methods. Also referred to as minimally invasive surgery, the technique allows for small incision access to the intra-abdominal cavity. The approach utilizes specialized equipment for the purposes of inflating the abdominal cavity with gas, deploying and exchanging instruments during the operation, and real time imaging with a videoscopic camera. Single port and robotic surgical procedures were developed from and utilize minimally invasive technologies.
[0005] A laparoscopic trocar is a surgical device used in laparoscopic procedures to pierce and access the wall of an anatomical cavity, thereby forming a passageway providing communication with the inside of the cavity. Other medical instruments such as videoscopes and operating instruments can thereafter be inserted through the passageway to perform various surgical procedures within the abdominal cavity. Multiple trocars are often used to accommodate a variety of specialized surgical instruments. Laparoscopic trocars are typically 5-15 mm in diameter.
[0006] When the procedures are over, the laparoscopic trocars are removed, leaving residual defects in the fascia-peritoneal layer. If trocar port defects are not repaired, there is risk of trocar site herniation (TSH). The incidence of post-operative TSH increases with use of larger trocar port sizes. The trocar site defect is located deep in the abdominal wall, making it difficult to view and for the surgeon to repair reliably.
[0007] Trocar site herniation (TSH) is a recognized complication of incomplete surgical repair. Symptoms are varied, but are frequently localized in nature. Major complications include omental and intestinal herniation, with incarceration and bowel obstruction. Fascial closure of any trocar insertion site larger than 5 mm has now been established and is routinely practiced worldwide.
[0008] However, the closure of such a trocar site fascial defect using the conventional suturing technique is often technically difficult, time consuming and frequently ineffective. Working in the port tissue tunnel is dangerous due to the narrow size of skin incision, thickness of the subcutaneous fatty layer, and recessed trocar port fascial defect. Moreover, blind suturing after the abdomen has been decompressed is dangerous.
[0009] Problems arise when both sides of the defect are not approximated or sutured. In overweight and (high Body Mass Index) obese patients with thick abdominal walls, reliable fascia closure is particularly difficult to achieve. This results in a higher TSH formation rate and associated complications, such as a bowel incarceration. Surgical literature reports an overall 6% trocar port herniation rate. Patients requiring, re-operation, re-hospitalization, and extended disability, experience significant economic loss.
[0010] A number of techniques and devices were designed to enable secure closure of the fascial layer defect. These are based on approaches in which suture is positioned on either side of the trocar defect, enabling tying and ligating suture by hand. For this purpose either a tapered suture or a variety of straight needles through which sutures are grabbed or clasped have been used. The Carter-Thomason or Riza-Ribe® needles have positioned a mechanical catch at the end of their needle assembly for grabbing the closure suture. An automated port closure suturing device is also available.
[0011] Although promoted as easy and quick methods, the needle based closure methods require several tedious steps involving frequent re-positioning of the camera, visualization of the needles during their entrance into the peritoneal cavity, and feeding of the graspers or suture passers with ends of sutures. All of these maneuvers have to be repeated in sequence for every trocar defect closed. Needle directed suturing techniques are time and effort consuming, even in the best of hands.
[0012] Needle based port closure methods were enhancements to the conventional method of port closure because tight working spaces were difficult to navigate with standard sutures. Moreover, a series of traumatic manipulations were often required when applying conventional sutures. These measures frequently include forceful pushing, pulling and retraction of the wound to achieve maximum exposure of the fascial defect. As manipulation of the wound increases, inflammation and risk of ensuing infection rise considerably. Edema and the collection of seroma or hematoma, predispose to wound dehiscence and trocar site hernia (TSH.)
[0013] To summarize, excessive manipulation of tissue frequently occur when conventional suturing techniques are used. Trauma undermines the “minimally invasive” advantages otherwise realizable with laparoscopic surgery. Patients are subject to post-operative incisional pain and other complications at their trocar sites. Suturing creates excessive tension at the wound site, increasing the risk of the wound pulling apart. Excessive pressure tension forces are among the most common cause of wound breakdown.
[0014] Intra-corporeal suturing techniques are used infrequently to close trocar port defects under direct vision from within the abdominal cavity. Instead, most trocar ports are dosed from the outside, with the abdominal wail in a flattened configuration. As a result, the residual defect within the fascial layer is poorly visualized by the surgeon.
[0015] No matter which suturing technique or needle is used, it is not possible to eliminate the risk of trocar site hernias complications. As described in Malazgirt (US Patent Application, pub #20060015142 published Jan. 19, 2006), the current incidence is reportedly between 0.77-3%. The reported rates of hernia show that there is no superior method in the safe closure of the trocar fascial defect. As complex laparoscopic surgery becomes more common, the incidence of this complication increases.
[0016] Eldridge and Titone (U.S. Pat. No. 6,120,539 Issued Sep. 19, 2000) proposed a prosthetic repair fabric constructed from a combination of non-absorbable tissue-infiltratable fabric which faces the anterior surface of the fascia and an adhesion-resistant barrier which faces outward from the fascia. This prosthetic requires the use of sutures to hold it in place.
[0017] Eberbach (U.S. Pat. No. 5,366,460 Issued Nov. 22, 1994) proposed the use of a non-biodegradable fabric-coated loop inserted through the defect into the fascia wall, pressing against the posterior fascia wall from the intra-abdominal pressure.
[0018] Agarwal et al (U.S. Pat. No. 6,241,768 Issued Jun. 5, 2001) proposed a prosthetic device made of a biocompatible non-biodegradable mesh, which sits across the fascia defect using the abdominal pressure to hold it in place.
[0019] Rousseau (Pat Pub #20030181988) proposed a plug made of biocompatible non-biodegradable material which covers the anterior side of the fascia, the defect, as well as the posterior side of the fascia.
[0020] Malazgirt (Pat Pub #20060015142) proposed a plug/mesh non-biodegradable combination for repair of large trocar wounds. It is stated that it requires at least a “clean flat area around with a radius of 2.5 cm”, and requires staples to hold it in place.
[0021] Ford and Torres (Pat Pub #20060282105) proposed a patch with a tether or strap, all made of non-biodegradable biocompatible material placed against the anterior wall of the fascia defect.
[0022] Sargeant et al (U.S. Pat. No. 8,617,206 Issued Dec. 31, 2013 proposed a biocompatible wound closure device with a plug member with a single tissue facing surface, where the plug is attached to an elongate body which goes through the trocar defect.
SUMMARY
[0023] A biodegradable device for providing scaffolding for a trocar defect to promote healing. The device consists of inner and outer scaffolding offset by a connector. The device is arranged so the distance between the lower surface of the outer scaffolding and upper surface of the inner scaffolding holds the device around the trocar defect while promoting tissue growth. The surfaces of the scaffolding in contact with the trocar defect are textured to maximize adherence to tissue.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The aforementioned features and advantages of the invention as well as additional features and advantages thereof will be more clearly understandable after reading detailed descriptions of embodiments of the invention in conjunction with the following drawings.
[0025] FIG. 1 shows one embodiment of the apparatus as it would appear on deployment in the trocar tunnel.
[0026] FIG. 2 shows the details of one embodiment of the coupling of the applicator to the scaffold inserted into a trocar defect and across the fascia planes of the wound.
[0027] FIG. 3 shows an embodiment of the biodegradable inner scaffolding.
[0028] FIG. 4 shows a side view of an embodiment of the biodegradable inner scaffolding.
[0029] FIG. 5 shows a top view of an embodiment of the biodegradable outer scaffolding.
[0030] FIG. 6 shows a top down view of the biodegradable scaffolding assembly as it would appear coupled.
[0031] FIG. 7 shows a side view of the inner applicator
[0032] FIG. 8 shows a side view of the outer applicator
[0033] FIG. 9 shows a side view of the outer applicator with the biodegradable outer scaffolding in place.
[0034] FIG. 10 shows an embodiment of the insertion of the inner scaffolding below the trocar defect.
[0035] FIG. 11 shows an embodiment of the connection of the inner scaffolding and outer scaffolding around the trocar defect
[0036] FIG. 12 shows an embodiment of the healing process with the applicator removed and the tissue healing around the scaffolding assembly
[0037] FIG. 13 shows the end of the healing process, with the tissue fully healed and the biodegradable scaffolding assembly dissolved.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0038] FIG. 1 shows views of one or more embodiments of the device configured to be implanted. In one or more embodiments, an applicator consists of a handle 102 , inner applicator 114 , outer applicator 104 , coupling to outer scaffolding 106 , and coupling to inner scaffolding 110 . In one or more embodiments, the biodegradable scaffolding consists of an outer scaffolding 106 , inner scaffolding 110 , and coupling 112 . The inner scaffolding 110 is meant to be inserted into the trocar defect and stays underneath the trocar defect once deployed. The inner scaffold 110 has a tissue facing surface that is meant to maintain contact with the lower surface of the tissue surrounding the trocar defect. The inner scaffold has a circular or elliptical cross section, such that it has a base diameter that is large enough to prevent it from extrusion through the trocar defect. In one or more embodiments, the base diameter varies with the size of the trocar defect being closed. The outer scaffolding 106 has a tissue facing surface that is meant to maintain contact with the upper surface of the tissue surrounding the trocar defect. The coupling 112 holds the two scaffolds in place so that the tissue stays in place, and while healing is encouraged to grow. In one or more embodiments the coupling 112 is ribbed to enable the device to be used with various thickness of tissue around the fascia defect. The outer scaffolding 106 , coupling 112 , and inner scaffolding 110 will be collectively referred to herein as the scaffold assembly. The mechanical properties of the scaffold both maintains alignment of the fascial planes of the defect during healing and provides a mechanical barrier to herniation during healing until the tissue is sufficiently healed to prevent herniation. The scaffold assembly bridges the trocar defect, and fascial edges are aligned to prevent extrusion of the scaffolding assembly, or prolapse of intra-abdominal structures such as bowel or omentum thru trocar defect. The support remains in place while the tissue heals then is resorbed once the tissue is sufficiently healed, the tissue then able to prevent egress without the need for additional support.
[0039] In one or more embodiments, the shape of the surface of the inner scaffolding and outer scaffolding may vary, where the base diameter of the inner scaffolding would be the largest distance across the center of the surface, and the major and minor diameters of the outer scaffolding would be the largest and smallest distance across its surface. In one or more embodiments each of the inner arid outer scaffolding could be scalloped circles. In other embodiments the inner scaffolding could be elliptical in shape. In other embodiments the inner or outer scaffolding or both could be one or more ellipses in a petal-like formation. In other embodiments the inner or outer scaffolding could be triangular.
[0040] The fascia has different characteristics on the top and bottom. The tissue aligning with the inner scaffolding 110 is made of a fine cellophane-like material called the peritoneum, while the fascia contacting the outer scaffold 106 is primarily muscle and subcutaneous fat. The trocar defect in the fascia may be a slit or star formation, such that it has a defect diameter. The inner scaffolding 110 placed below the defect but larger than this diameter would not be easily extruded through the defect. For a slit defect configuration, the inner scaffold will extend well beyond the width of the slit, for a star defect configuration this would be expected to buttress and extend well beyond the fascial tissue flaps.
[0041] In one or more embodiments, the tissue facing surface of the inner scaffolding 110 contacting the peritoneum has a texture on it which acts to increase the friction between the peritoneum and scaffold to reduce or eliminate the possibility of extrusion. Smaller perforation sizes in the inner scaffolding 110 act to bend or fold the peritoneum into it, helping to keep the tissue in place during the healing process. Larger perforation sizes in the upper scaffold 106 allow the muscle and fat to protrude through it, both to encourage growth of the tissue above and around the implanted the device and acting further to keep the scaffold in place.
[0042] In one or more embodiments the inner applicator 114 and outer applicator 104 are configured to be held by a user to implant and align the device. In other embodiments, the inner applicator 114 and outer applicator 104 are configured to be coupled with a robotic device to enable a user to remotely implant the device.
[0043] In one or more embodiments the inner applicator 114 is connected to the biodegradable inner scaffold 110 by screwing into a threaded cylinder at its interior end, which is part of the biodegradable inner scaffold. In one or more embodiments, the inner applicator 114 slides inside the outer applicator 104 via a handle 102 attached to the inner applicator 114 at the exterior end. As shown in FIG. 8 and FIG. 9 , the outer scaffolding 106 is secured to the interior end of the outer applicator 104 by and interference fit 1006 .
[0044] FIG. 2 shows a detailed view of the coupling between the inner scaffolding 110 , outer scaffolding 106 and fascia 126 . In one or more embodiments, the inner scaffolding 110 is attached to the outer scaffolding 106 by a coupling 112 between the two. The scaffold assembly in place will have enough of a hold on the fascia 126 enough to hold it in place without injuring it. The outer scaffold 106 sits on top of the fascia 126 . It is not necessary for the scaffold assembly to cover the entire defect. Rather, it serves the purpose of stabilizing the tissue and the edges of the defect anatomically aligned and co-apted to facilitate reliable wound healing.
[0045] The scaffold assembly is kept in place to hold, but not overly compress, the fascia 126 surrounding the trocar defect 216 to promote the healing process. In this figure, the inner scaffolding 110 is shown to be smaller than the outer scaffolding 106 . In one or more embodiments, the purpose of the inner scaffolding is to stabilize the scaffold assembly to the defect, and so it must be at least wider than the width of the trocar defect separation, and wide enough to be able to couple with the coupling 112 .
[0046] The fascia surface is different above and below. The upper fascia surface 128 is a combination of fascia, muscle and fat, more flexible than the lower fascia surface 130 which is peritoneum, a cellophane like substance with little flexibility. The scaffolding serves to align the fascial edges in the anatomic plane and provide a tension free stabilization of tissue critical elements of the abdominal wall. The outer scaffold 106 engages and compresses a combination of subcutaneous fat, fascia and muscle which because of its flexibility is encouraged to move up and around the perforations in the outer scaffold 106 . The inner scaffolding 110 directly engages the innermost surface of the abdominal wall, or peritoneal lining 130 , creating a bond due to the friction between the abdominal wall and texturing of the inner scaffolding surface, stabilizing the device and indirectly supporting the compressive action of the implantable device.
[0047] FIG. 3 shows one embodiment of the inner scaffold 110 from a top down view. The inner scaffold is constructed so that it has a set of perforations 406 surrounded by a perimeter 402 with a coupling 112 . The coupling 112 enables the inner scaffold to be coupled to the outer scaffold 110 . The perforations 406 perform several functions. First, the perforations facilitate the ingrowth of tissue into the wound matrix, promoting faster healing. Perforations also reduce the profile of the device by permitting tissue to position around and through the device. This is expected to minimize patient discomfort of the patient and by further reducing the device profile, minimize the likelihood of feeling a palpable device like this. Finally, the design reduces the biopolymer load and the amount of material required to make the device.
[0048] In one or more embodiments, a counter-rotational or frictional control feature can be added to the tissue facing surface of the inner scaffolding 110 which is intended to contact the peritoneum such as small protrusions of a conical shape to prevent the tendency to move during the process of tightening the outer scaffolding 104 onto the coupling 112 . In one or more embodiments, this frictional control feature is implemented where the face of the inner scaffolding 110 is textured with a patterned surface to offer frictional control such that, in use, the textured side is placed in direct contact with the fascia and associated layers of the abdominal wall. Its purpose is to hold them in place to facilitate the healing process. In one or more embodiments, the texture is a non-smooth (unpolished) frictional control surface feature to assure that the inner scaffolding 110 remains in position and does not slide or shift laterally during the healing interval.
[0049] FIG. 4 shows a side view of the inner scaffold 110 . The inner scaffold consists of an inner disk 502 and a coupling 112 . In one or more embodiments, the coupling 112 consists of a cylinder 504 with threads inside to enable it to attach to a device for insertion into the trocar defect. The outside of the coupling 506 provides the connection surface to the outer scaffold 106 . In one or more embodiments, the coupling provides a surface for a friction coupling such that the outer diameter of the coupling gets slightly larger as it gets closer to the inner disk. In other embodiments it is a snap fit, where the outside surface of the coupling has one or more teeth which mate with the inner surface of the inner ring of the outer scaffold in the same way a cable tie works.
[0050] In one or more embodiments, it is understood that the coupling could be a different mechanism, as long as it provides a method for decoupling the inner and outer scaffolding. In one or more embodiments this could be threads on the outside of the coupling and threads on the inner ring of the outer scaffolding. In other embodiments this could be a living hinge snap engagement, where the inner scaffolding has a groove and the outer scaffolding has tines on it such that the tines deflect during installation, returning to undeflected position once they meet the groove. In other embodiments, the coupling could be a keyed circular post where the inner ring of the outer scaffolding is shaped as a keyed circular hole.
[0051] FIG. 5 shows a top view of the outer scaffold 106 . The outer scaffold consists of a perimeter 602 , a central ring 606 . The central ring 606 has an inner diameter slightly greater than the outer diameter of the inner applicator 114 , which enables the outer scaffold to slide over it during the insertion process. The large openings in the outer scaffold 604 act to make the device lower profile as the upper surfaces of the fascia, primarily fat and muscle tissue, protrude through it, somewhat covering it and making it low profile. This reduces the likelihood that the device will be palpable to the patient. The shape of the outer scaffold 106 along with the shape and size differences between the inner scaffold and outer scaffold will encourage the tissue edges to evert, which is further encourages tissue healing to occur.
[0052] FIG. 6 shows a top view of the inner scaffold 110 and outer scaffold 116 as they would be assembled in place. There would also be tissue between the two devices, but this is not shown for clarity. In one or more embodiments, the outer scaffold 116 would be wider as the inner scaffold 110 has to be inserted through the trocar defect and acts as an anchor to hold the scaffolding in place, where the outer scaffold 116 does not have to be inserted through the trocar defect and so can be wider than even the actual defect as long as it fits into the tunnel. The coupling 112 fits through the inner ring of the outer scaffold 606 , such that the outer surface of the coupling and the inner surface of the inner ring share a connection means which enables one to insert one into the other easily while making it difficult for the two to unmate without purposely doing so. In one embodiment this is a friction fit, in other embodiments it is a snap fit, but it is recognized that there are many other ways of performing this function.
[0053] Because the scaffold encourages the fascia to surround it, the geometry provides less of a need for tension around the trocar defect.
[0054] On insertion, the coupling 112 is inside the inner ring of the outer scaffold 106 . This aligns the two parts of the scaffolding over the trocar defect, such that even if the outer scaffold 106 is misaligned relative to the direction of the defect, it still provides a large surface for the tissue to penetrate and heal faster because of the circular geometry of the inner scaffold 110 .
[0055] FIG. 7 shows a side view of the inner applicator 114 . In one or more embodiments, the inner applicator has a handle 102 at the outer end to enable to user to grasp it easier. In other embodiments the inner applicator would have a coupling to enable it to be attached to a robotics controller. The inner applicator has a stem 902 with a threaded inner end 904 . The threads are such that they are able to connect to the inner threads of the coupling 112 , and the diameter of the stem 902 is such to allow the outer scaffold 106 to slide over the inner diameter of the central ring.
[0056] FIG. 8 shows a side view of the outer applicator 104 including an outer cylinder 1002 , a dimensional fitting 1004 sized to hold the outer scaffolding 106 in place, and a hole through the center of the cylinder 1006 to allow the inner applicator 114 to slide through. The dimensional fitting 1004 is constructed so that the outline is circular but the outer scaffolding may be elliptical and have a larger major diameter than the diameter of the outer applicator. In one or more embodiments, this is accomplished by having the dimensional fit along the minor diameter of the outer scaffolding, where the outer scaffolding sticks out beyond the outer applicator 104 on either side if its major diameter is larger.
[0057] FIG. 9 shows the outer applicator 104 with the outer scaffolding 106 in place. In one or more embodiments, the outer dimensions of the outer scaffolding 106 along its minor diameter are slightly larger than the inner dimensions of the outer applicator wall 1008 , so that the outer scaffold is secured in the outer applicator with an interference fit. This means that the outer scaffolding 106 is inserted into the space in the outer applicator 1010 and is held in place with sufficient force that it does not drop out, but with less force than the coupling 112 in combination with the inner scaffolding 110 pulls on it once the inner scaffolding is set beneath the fascia layer. This acts to keep the outer scaffolding 106 stable during the insertion; that is, the outer scaffolding 106 stays aligned with the inner scaffolding 110 such that it can be inserted onto the connector during the insertion process.
General Composition of the Trocar Defect Scaffolding Device
[0058] Materials specified for the trocar defect scaffolding device are specific for its intended application and use. The scope of materials that will satisfy the requirements of this application is unusually narrow. This is a direct consequence of the specificity and functional demands characteristic of the intended surgical application.
[0059] The intention for the trocar defect scaffolding device is to encourage healing by providing surface area and open space to facilitate tissue growth. This requires a known and finite healing interval of some three to five months. Its purpose fulfilled at the end of this period, making continued presence of the scaffolding a potential liability. To prevent it from becoming a source for irritation once the healing process is completed, the implanted scaffolding should be removed. Consequently, to avoid the need for a second surgical intervention to remove the device, Maurus and Kaeding (Maurus, P. B. and Kaeding, C. C., “Bioabsorbable Implant Material Review”, Oper. Tech. Sports Med 12, 158-160, 2004) found it was a primary requirement for a wound closure device is that it is biodegradable. This means that the materials will degrade or disintegrate, being absorbed in the surrounding tissue in the environment of the human body, after a definite, predictable and desired period of time. One advantage of such materials over non-degradable or essentially stable materials is that after the interval for which they are applied (i.e. healing time) has elapsed, they are no longer a contributing asset and do not need subsequent surgical intervention for removal, as would be required for materials more stable and permanent. This is most significant as it minimizes risks associated with repeat surgeries and the additional trauma associated with these procedures.
[0060] A disadvantage of these types of materials is that their biodegradable characteristic makes them susceptible to degradation under normal ambient conditions. There is usually sufficient moisture or humidity in the atmosphere to initiate their degradation even upon relatively brief exposure. This means that precautions must be taken throughout their processing and fabrication into useful forms, and in their storage and handling, to avoid moisture absorption. This is not a serious limitation as many materials require handling in controlled atmosphere chambers and sealed packaging; but it is essential that such precautions are observed. Middleton and Tipton (Middleton, J. and Tipton A. “Synthetic Biodegradable Polymers As Medical Devices” Medical Plastics and Biomaterials Magazine, March 1998) found that this characteristic also dictates that their sterilization before surgical use cannot be done using autoclaves, but alternative approaches must be employed (e.g. exposure to atmospheres of ethylene oxide or gamma radiation with cobalt 60 ).
[0061] While biodegradability is an essential material characteristic for the wound closure device, the intended application is such that a further requirement is that the material is formulated and manufactured with sufficient compositional and process control to provide a precisely predictable and reliable degree of biodegradability. The period of biodegradability corresponds to the healing interval for the trocar defect in the fascia layer, which is typically three to five months.
[0062] In these materials, simple chemical hydrolysis of the hydrolytically unstable backbone of the polymer is the prevailing mechanism for its degradation. As discussed in Middleton and Tipton (Middleton, J. and Tipton A referenced previously), this type of degradation when the rate at which water penetrates the material exceeds that at which the polymer is converted into water-soluble materials is known as bulk erosion.
[0063] Biodegradable polymers may be either natural or synthetic. In general, synthetic polymers offer more advantages than natural materials in that their compositions can be more readily finely-tuned to provide a wider range of properties and better lot-to-lot uniformity and, accordingly, offer more general reliability and predictability and are the preferred source.
[0064] Synthetic absorbable materials have been fabricated primarily from three polymers: polyglycolic acid (PGA), polylactic acid (PLA) and polydioxanone (PDS). These are alpha polyesters or poly (alpha-hydroxy) acids. The dominant ones are PLA and PGA and have been studied for several decades. Gilding and Reed (Gilding, D. K and Reed A. M., “Biodegradable Polymers for Use in Surgery” Polymer 20, 1459-1464) discussed how each of these materials has distinctive, unique properties. One of the key advantages of these polymers is that they facilitate the growth of blood vessels and cells in the polymer matrix as it degrades, so that the polymer is slowly replaced by living tissue as the polymer degrades (“Plastic That Comes Alive: Biodegradable plastic scaffolds support living cells in three dimensional matrices so they can grow together into tissues and even whole organs” by Cat Faber Strange Horizons http://www.strangehorizons.com/2001/20010305/plastic.shtml)
[0065] In recent years, researchers have found it desirable for obtaining specific desirable properties to prepare blends of these two dominant types, resulting in a highly useful form, or co-polymer, designated as PLGA or poly (lactic-co-glycolic acid). Asete and Sabilov (Asete, C. E. and Sabilov C. M., “Synthesis and Characterization of PLGA Nanoparticles”, Journal of Biomaterials Science—Polymer Edition 17(3) 247-289 (2006)) discuss how this form is currently used in a host of FDA-approved therapeutic devices owing to its biodegradability and biocompatibility.
[0066] In one or more embodiments, the biodegradable scaffold may be made of biodegradable material of different stability (i.e. half-life). While it is important for the material that is in direct contact with the fascia or lending support to that (the inner scaffolding 110 , and outer scaffolding 106 ) needs to stay in place for a few months, while the rest of the implantable structure can degrade significantly in a matter of weeks without affecting the performance of the payload. In one or more embodiments, the coupling 112 would degrade sooner than the inner scaffolding 110 and outer scaffolding 106 , so that the ends of the defect are allowed to grow together while protecting the surface of the defect.
Description of Use of One or More Embodiments of the Invention
[0067] One or more embodiments of the use of this invention are described herein. In one or more embodiments, the outer applicator 104 is coupled to the outer scaffold 106 first, then the inner applicator 114 is inserted through the outer applicator 104 and then coupled to the inner scaffold 110 through the coupling 112 . The outer scaffold 106 is fitted over the coupling 112 . The combination of the scaffolds, connector and applicators creates what we will refer to as the applicator assembly.
[0068] As shown in FIG. 1 , the applicator assembly is inserted into the trocar tunnel surrounded by the skin 122 , subcutaneous fat 120 with the outer scaffold 106 connected to the outer applicator 104 and the inner applicator 114 attached to the inner scaffold 110 . The user is able to manipulate the assembly using the handle 102 . At this point, the inner scaffold 110 has not reached the trocar defect 124 or surrounding fascia tissue 126 .
[0069] Prior to insertion, the device is assembled in one or more embodiments as follows. The inner applicator 114 is inserted into the central hole of the outer applicator 1006 such that the screw end is closest to the inner end of the outer applicator 1004 . Either before inserting the inner applicator into the outer applicator or after, the outer scaffolding 106 is attached to the inner end of the outer applicator by inserting it into the dimensional fit 1004 . If the inner applicator 114 is in place, this is accomplished by sliding the outer scaffolding over the end of the inner applicator 114 towards the dimensional fit of the outer applicator 1004 . Finally, screw the coupling 112 onto the threads of the inner applicator 904 .
[0070] As shown in FIG. 10 , the inner scaffold 110 is pushed through the trocar defect 1206 . Once the inner scaffold is pushed through the trocar defect 124 , the user exerts a slight upward pressure on the handle 102 of the inner applicator 114 to keep the inner scaffold 110 securely against the lower fascia surface 126 and under the trocar defect 124 .
[0071] In one or more embodiments where the outer scaffold 106 is made to slide over the connector the user will also exert a downward pressure on the tube of the outer applicator 1002 to move the outer scaffold 106 over the coupling 112 toward the inner scaffold until there is a positive force pushing back. When the outer scaffold 106 is over the coupling 112 , the coupling will pass through the inner center hole in the outer connector, stabilizing it while the insertion is completing. In other embodiments, the tube is rotated where the outer scaffold has a threaded interface with the connector. At this point, the device is set in place, as shown in FIG. 11 .
[0072] Once the device is in place, the outer applicator 104 can be decoupled from the outer scaffold 106 and the inner applicator 114 is decoupled from the coupling 112 . The user is then free to close the outer wound 122 . At this point the skin is closed and over a period of time the skin 122 and subcutaneous fat 120 heal and grow into the former trocar tunnel. The trocar defect also heals and you just have the fascia 126 . The result of this is shown in FIG. 12 .
[0073] Over the next few months, the wound edges will grow into each other. In one or more embodiments, the fascia layers are encouraged to grow into the device itself. Over time, the device degrades and eventually dissolves into the body to be excreted without any known side effects, leaving behind a healed fascia 126 under the layers of skin 122 and subcutaneous fat 120 as shown in FIG. 13 . | A method for maintaining the alignment of the edges of a trocar defect by inserting into a defect a device for compressing the tissue such that part of the device is above while the other is below the defect, then pulling back on the device so that the part below the defect is up against the defect, then while holding the device below the defect in place, push down on the part above the wound so that it compresses the tissue. Finally, release the device from the insertion tool. | 0 |
FIELD OF THE INVENTION
[0001] This invention relates to an economically viable method for producing hydrogen by the reaction between water and preformed carbon material.
DESCRIPTION OF THE RELATED ART
[0002] Hydrogen is one of the most promising energy sources for the new century, especially in view of the great progress made in the field of hydrogen storage in the last three years. It can be foreseen in the near future that the utilization of hydrogen as an energy source will be on the rise, and as such, the need for finding new and economically viable sources of hydrogen is urgent.
[0003] In the present time, there are four main processes for producing hydrogen: (1) natural gas-water reforming process; (2) coal-gasification; (3) heavy oil-partial oxidation; and (4) water electrolysis.
[0004] In the natural gas-water reforming process, natural gas and steam are co-fed into a fixed bed reactor. The catalyst, which is usually a nickel based composition, is placed in the reactor. The reaction is carried out at a temperature of between 700-900° C. Hydrogen, CO and small amounts of CO 2 are produced. The CO which is produced from this reaction, is forwarded to a shift reactor wherein the CO reacts with water at 300 to 500° C. to produce hydrogen and carbon dioxide (also known as the water-gas shift reaction). Currently, this is the dominant process for producing hydrogen used in industry.
[0005] In the coal-gasification process, coal, water and oxygen are used as the feed stock. The operating temperature normally surpasses 1200° C. Both hydrogen and carbon monoxide are produced in the reaction. In order to increase the yields of hydrogen, the carbon monoxide is fed into a shift reactor when the carbon monoxide reacts with water to form hydrogen and carbon dioxide. The major reactions are as follows:
coal+O 2 →CO+heat;
coal+H 2 O+heat→H 2 +CO; and
CO+H 2 O→CO 2 +H 2 (water-gas shift reaction).
[0006] Since hydrocarbons which are heavier than naphtha cannot be used directly under the water reforming process to produce hydrogen, the heavy oil-partial oxidation process has been conceived. In the heavy oil-partial oxidation process, heavy oil is allowed to react with a mixture of oxygen and water in the presence of a catalyst at a temperature of 600° C. This reaction will also occur without a catalyst at a temperature of above about 1100° C.
[0007] The electrolysis of water is suitable only where cheap electricity is available. In this process, hydrogen is produced by the direct pyrolysis of water in a battery cell where hydrogen and oxygen are the products.
2H 2 O+2e − →H 2 +2OH − —cathode reaction
2OH − →½O 2 +H 2 O—anode reaction
H 2 O→H 2 +½O 2 —cell reaction
[0008] The cost of this process is comparatively higher than the others, however there is research being performed on the development of more efficient elements.
[0009] In addition to the above four methods for producing hydrogen, there are several technologies in development which are promising. One of them is the thermal cracking of natural gas which has the following reaction scheme CH 4 →C+2H 2 . The operating temperature is around 800° C. with hydrogen and carbon black formed as the product. The carbon black can be further used as fuel or as a component in ink or paint. It has been suggested that the thermal cracking of natural gas process is competitive with the natural gas-steam reforming process.
[0010] Each of the above described methods for producing hydrogen is too inefficient and costly to compete with other sources of energy currently available. Thus there is a need for a process for producing hydrogen which is more economical.
BRIEF SUMMARY OF THE INVENTION
[0011] The present invention, in part, is drawn to a method for producing hydrogen comprising contacting water with a preformed carbon material. This preformed carbon material is prepared by the decomposition of a hydrocarbon in the presence of a metal catalyst.
[0012] The invention is also drawn to a method of producing hydrogen comprising catalytically decomposing hydrocarbons to form hydrogen and a preformed carbon material, and a step of contacting water with the preformed carbon material to form hydrogen, CO 2 , and CO.
[0013] According to one aspect of the invention, most of the preformed carbon material is in the form of carbon nanofibers or nanotubes with catalyst particles attached to one end of the fiber or tube.
[0014] Additional features and advantages of the invention will be set forth in the following description, and in part will be apparent from the description, or may be learned by practice of the invention. These variations are considered to be within the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] [0015]FIG. 1 is a TEM image of the preformed carbon nanofibers or nanotubes; and
[0016] [0016]FIG. 2 is a mass spectrum showing the amount of hydrogen, CO, and CO 2 formed at various temperatures.
DETAILED DESCRIPTION OF THE INVENTION
[0017] The present invention includes a method for producing hydrogen by the reaction between water and preformed carbon material at a temperature of about 300° C. to about 1000° C. under 0.1 atm to 100 atm pressure. The method further comprises a step of contacting a hydrocarbon with a metal to form the preformed carbon material.
[0018] The invention also includes a method of producing hydrogen comprising catalytically decomposing hydrocarbons to form hydrogen and a preformed carbon material, and a step of contacting water with the preformed carbon material to form hydrogen, CO 2 , and CO.
[0019] The preformed carbon material comprises at least 20 wt % carbon nanotubes or nanofibers bonded to a metal. Preferably, the preformed carbon material comprises at least 50 wt % carbon nanotubes or nanofibers bonded to a metal. In other words, the preformed carbon material has a molar ratio of carbon to metal ranging from 10,000:1 to 1:10. Preferably, the molar ratio of carbon to metal is from 5,000:1 to 100:1.
[0020] The metal which is bonded to the carbon nanotubes or nanofibers is a transition metal which optionally contains a support. The transition metal is preferably a member of Group VIII of the periodic table, and the support is preferably selected from the group consisting of alkaline earth oxides, rare earth oxides, alkali oxides, silica, zirconia, yttrium oxide, zeolites, aluminosilicates, alumina, and mixtures thereof. The relative weight ratio of the support to the transition metal is 20:1 to 1:1. Preferably, the transition metal is nickel or cobalt which is supported on either magnesium oxide or lanthanum oxide.
[0021] The hydrocarbons useful in the formation of preformed carbon material are selected from the group consisting of alkanes, alkenes, alkynes, aromatics and mixtures thereof. Preferably, the hydrocarbons are C 1 -C 12 alkanes, C 1 -C 12 alkenes, C 1 -C 6 alkynes, and C 6 -C 14 aromatic hydrocarbons.
[0022] The activity of metals varies depending upon the substrate. For example, Ni or Co has a higher activity using CH 4 whereas Fe has a higher activity when using C 2 H 5 .
[0023] In the step of contacting a hydrocarbon with a metal to form the preformed carbon material, hydrogen is present, and optionally other reductive or inert gases. Preferably, this step is performed in an oxygen-poor atmosphere. More preferably, oxygen is less than 5 wt % of the gas composition.
[0024] Once the preformed carbon material is formed, the hydrocarbon feed is discontinued, and the preformed carbon material is exposed to an excess of water thereby forming hydrogen. Under the conditions in which the hydrogen forming step is performed, the water is in the form of steam. The conditions for this step range from 300° C. to about 1000° C. under 0.1 atm to 100 atm. Preferably, the temperature ranges from 400-900° C. and the pressure is 1 to 80 atm.
[0025] Both the step of forming the preformed carbon material and the catalytic decomposition of water step can be performed in either a batch or continuous process. Preferably, the catalytic decomposition of water step is performed in a continuous process at a flow rate of 1 to 5,000 ml/min-mg carbon. In other words, the flow rate is from 10 of carbon dioxide begins to increase. Hydrogen starts to form at around 450° C., and at 550° C. both carbon dioxide and hydrogen reach an apex. At above 550° C., CO 2 has a continuous slight drop. The composition of the carbon containing products strongly depends on the temperature and H 2 O/C ratio. An excess of water favors the formation of carbon dioxide.
[0026] It was found that the purified carbon nanotubes or nanofibers having the catalyst particle removed produce very little hydrogen at temperatures around 800° C. whereas the carbon nanotubes or nanofibers of the present invention contained in the catalyst produced more than a hundred liters of hydrogen from 100 milligrams of nickel based catalyst. It is well known that the direct reaction between water and carbonaceous materials (such as water-coal reaction and water-coke) requires temperatures as great as 1200° C. to overcome the high thermodynamic barrier between reactants and products. The dramatic drop in the required reaction temperature of the inventive process is due to the presence of the transition metal attached at one end of the carbon nanotubes.
[0027] Without being bound to theory, it is presumed that the electron cloud of the H 2 O molecule interacts with the surface of the transition metal based catalyst, and the H—O—H bonding weakens or even breaks. Carbon atoms which are nearby diffused throughout the body or surface of the catalyst particles and react with O to form CO 2 or CO. Subsequently, two H atoms will combine together and form H 2 . Low temperatures favor the formation of CO 2 while high temperatures favor CO due to the equilibrium reaction:
2CO C+CO 2 +heat.
[0028] In the first step of forming the preformed carbon materials, the decomposition of the hydrocarbons is carried out at 300 to 1000° C., more preferably from 400 to 900° C. The pressure of the decomposition reaction is from 0.1 to 100 atm, and preferably from 1 to 80 atm.
[0029] The amount of hydrogen gas used in the first step is very small compared to the amount of hydrogen gas produced in the second step. From 100 milligrams of nickel based catalyst, 100 milliliters is required to reduce the catalyst, but from the same 100 milligrams of reduced catalyst containing tens of grams of carbon nanofibers, over 100 liters of hydrogen are produced with steam. It has been observed that the carbon material is consumed in the reaction based on the following observations. First there is the production of the carbon containing byproducts CO 2 and CO. Second, the weight of the carbon sample dramatically drops after the reaction.
[0030] The following specific examples are provided to illustrate the invention. It will be understood, however, that the specific details given in each example have been selected for purposes of illustration and are not to be construed as the limitations of the invention.
EXAMPLE 1
[0031] In the first step, 30 milligrams of Ni catalyst is supported on magnesium oxide support. The Ni/MgO catalyst is placed into a reactor. Hydrogen is blown over the Ni/MgO catalyst as the temperature is raised to 700° C. The hydrogen gas is discontinued and CH 4 gas is blown over the catalyst for about half an hour, thereby producing the preformed carbon material containing mostly carbon nanofibers or nanotubes bonded to the Ni/MgO catalyst at the ends of the fibers.
[0032] In the same reactor, CH 4 is discontinued and an excess of steam is blown over the preformed carbon material at 550° C. thereby producing hydrogen, CO 2 and CO.
EXAMPLE 2
[0033] 50 milligrams of a pre-reduced Co/MgO catalyst are placed into a reactor. The temperature is raised to 600° C. and C 2 H 4 is added for about one hour. Both hydrogen and the preformed carbon materials are produced. The C 2 H 4 is discontinued and steam is added above the preformed carbon materials containing the Co/MgO catalyst. The temperature is raised to 550° C. Hydrogen, CO and CO 2 are obtained. | The present work provides a new route for production of hydrogen via water and preformed carbon materials at a relatively low temperature. The preformed carbon materials comprise carbon nanotubes or nanofibers bonded to a transition metal and are obtained by the catalytic decomposition of hydrocarbons in a reductive atmosphere in the presence of the transition metal catalyst. Experimental results demonstrate that the transition metal bonded to the carbon nanotubes or nanofibers has a high activity for the production of hydrogen at temperatures around 450° C. | 2 |
FIELD OF THE INVENTION
The present invention relates to methods for bleaching lignocellulosic materials in order to prepare pulps for the manufacture of paper and, more particularly, to improve chlorine-free bleaching processes.
BACKGROUND
In the bleaching of kraft and hardwood pulps, the main objective is to brighten the pulp with a minimum of damage to the cellulose backbone of the fiber.
In the past, the most effective means for brightening pulp was the use of chlorine-containing bleaching agents. However, due to environmental concerns about chlorinated wastes, particularly dioxins from the bleaching process, the industry is moving away from chlorine-based bleaching processes in order to decrease the amount of chlorine required in the bleaching stages.
Oxygen-based bleaching procedures which are rapidly gaining popularity as substitutes for chlorine include oxygen, ozone and hydrogen peroxide. The oxygen-based bleaching procedures are currently being implemented in multi-step bleaching sequences. An oxygen delignification stage may provide up to 65% delignification on kraft and sulfite pulps. In the industry, however, most mills operate oxygen stages with delignification degrees between 40 and 45% due to a decrease in the selectivity of the reaction at higher degrees of delignification. When operating at delignification degrees above about 50%, pulp viscosity and pulp strength properties tend to drop sharply. Accordingly, the selectivity of the oxygen-based delignification agents is much lower than with chlorine-based chemicals.
One oxygen-based delignification process which has been proposed as a replacement for chlorine-based methods employs a monopersulfate or monoperoxysulfate solution as disclosed in U.S. Pat. Nos. 4,404,061 and 4,475,984 to Cael. The Cael patents describe the use of monoperoxysulfate to bleach pulp at a pH ranging from 2 to 12 and preferably 3 to 12. While Cael demonstrates that monoperoxysulfate bleaching is a viable process, he also suggests that if additional brightness is desired, various standard bleaching techniques may be applied to the monoperoxysulfate bleached pulp. Without standard bleaching techniques, attempts to gain additional brightness improvement using the Cael process typically result in a decrease in selectivity and viscosity of the resulting pulp.
Another chlorine-free treatment process is disclosed in U.S. Pat. No. 5,091,054 to Meier et al. which relates to the use of a peroxymonosulfuric acid pretreatment stage in combination with an oxygen and/or peroxide delignification stage. According to Meier et al., pretreatment with monoperoxysulfuric acid at a pH ranging from 3 to 5 achieves the optimum delignification efficiency. However, the use of peroxymonosulfuric acid at a pH ranging from 3 to 5 which is suggested by Meier et al. typically results in a reduction of delignification selectivity as indicated by the viscosity loss of the treated pulp.
It is therefore an object of the invention to provide a substantially chlorine-free delignification and bleaching process for kraft pulp.
Another object of the invention is to provide an improved chlorine-free delignification and bleaching process for kraft pulp whereby reduction in the physical properties of the pulp conventionally associated with delignification is avoided.
Still another object of the invention is to provide an improved method for elementally chlorine-free bleaching of lignocellulosic materials wherein the selectivity remains high even at high degrees of delignification.
Yet another object of the invention is to provide a method of the character described which uses readily available agents.
SUMMARY OF THE INVENTION
With regard to the above and other objects, the present invention is directed to a process for bleaching and delignifying lignocellulosic pulp such as kraft pulp. The process comprises reacting the pulp with an aqueous solution containing an alkali or alkaline earth metal salt of a monoperoxysulfuric acid while maintaining a substantially neutral pH. An advantage of the process of the present invention is that the selectivity of the treatment remains high even at delignification degrees above about 60% by weight.
The term "selectivity" is defined as a ratio of the change in Kappa number to change in viscosity as a result of the bleaching and delignification process. As is known, the Kappa number is related to the amount of lignin remaining in the pulp. As the lignin content decreases, so does the Kappa number. In general, a significant drop in the Kappa number indicates a significant bleaching effect. However, an increase in effectiveness of the bleaching agent is almost always accompanied by a decrease in pulp physical properties such as viscosity. The selectivity is a measure of the ability of a treatment to achieve a significant Kappa reduction with a minimum loss of viscosity.
The benefits of maintaining a neutral pH during monoperoxysulfate delignification and bleaching in accordance with the invention were unexpected and could not be predicted based on well known theories relating to delignification and bleaching. In particular, the high selectivity rates even at high degrees of delignification were unexpected. Accordingly, the ability to maintain high selectivity at high degrees of delignification is truly remarkable particularly for a non-chlorine based bleaching technique.
BRIEF DESCRIPTION OF THE DRAWINGS
Other benefits and advantages of the invention may be understood by reference to the figures in conjunction with the following description in which:
FIG. 1 is a graphical representation of delignification selectivity over a range of pH values; and
FIG. 2 is a graphical representation of how the pH of the pulp during treatment with a salt of a monoperoxy sulfuric acid affects the Kappa number and the viscosity of pulp over a range of pH values.
DETAILED DESCRIPTION OF THE INVENTION
With regard to the process for the delignification of a lignocellulosic pulp such as a kraft pulp, a key feature of the present invention is the use of an alkali or alkaline earth metal salt of a monoperoxysulfuric acid at a substantially neutral pH. By "substantially neutral pH" it is meant that the pH preferably ranges from about 6.5 to about 9.0, more preferably from about 6.8 to about 8.5, and most preferably from about 7.0 to about 7.6.
The alkali or alkaline earth metal salts of the monoperoxysulfuric acid may be selected from the sodium, potassium, calcium, magnesium, lithium, barium, rubidium, cesium, and strontium salts of the monoperoxysulfuric acid. The neutral monoperoxysulfuric acid salt may be produced on site or may be purchased off site and transported to the bleaching location. One procedure which may be used to generate the reactants on site is to combine hydrogen peroxide, sulfuric acid and an alkali or alkaline earth metal carbonate, bicarbonate, oxide or hydroxide in amounts sufficient to form the neutral monoperoxysulfuric acid salt. The amount of each reactant may range from about 1 to about 2 moles hydrogen peroxide, from about 1 to about 3 moles sulfuric acid and from about 2 to about 6 moles of alkali or alkaline earth metal carbonate, bicarbonate, oxide or hydroxide depending on the amount of sulfuric acid used and the pH required. It is preferred to maintain an excess of a buffering compound in the solution, such as sodium bicarbonate in order to more easily maintain the desired pH throughout the treatment stage. Accordingly, the solution may contain as much as about 15 to about 20 wt. % buffer such as sodium bicarbonate in addition to the alkali or alkaline earth metal salt of the monoperoxysulfuric acid.
The amount of alkali or alkaline earth metal salt of monoperoxysulfuric acid used to treat the pulp is preferably within the range of from about 0.1 to about 8 wt. % (as H 2 O 2 ) based on the oven dried weight of the pulp, more preferably from about 0.2 to about 5 wt. % and most preferably from about 2 to about 3 wt. %. More or less neutral monoperoxysulfuric acid salt may be used, however, the foregoing amounts are sufficient for most bleaching purposes.
Neutral monoperoxysulfuric acid salt bleaching may be conducted at temperatures ranging from about 20° to about 100° C., preferably from about 40° C. to about 80° C. and for periods of time ranging from about 30 minutes to about 3 hours or more. During the bleaching sequence, the pulp will typically have a consistency of about from 5 to about 20 wt. % or more.
A typical pulp treating sequence includes a heavy metals removal stage as generally practiced in the industry. Prior to bleaching and delignification, metals may be removed from the pulp by pretreating the pulp with chelating agents such as sodium or potassium orthophosphates, sodium or potassium pyrophosphates, nitrilotriacetic acid (NTA), ethylenediaminetetra(methylene-phosphonic) acid, ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), hydroxyethylenediaminetriacetic acid, diethylenetriaminepentamethylenephosphonic acid (DTMPA), and the alkaline metal salts thereof to name a few. The second stage of the bleaching sequence includes the neutral monoperoxysulfuric acid salt bleaching step (P ns ), and the third stage will typically be a standard alkaline extraction stage to remove the lignin. Such alkaline extraction stages include alkaline extraction (E), oxygen reinforced extraction (E o ) and oxygen and peroxide reinforced extraction (E op ) stages. If desired, the pulp may be further bleached to a GE brightness of 85 to 88% by an elementally chlorine-free sequence such as DED or by a totally chlorine-free sequence such as ZQP. Particularly preferred are the following bleaching sequences: E o P ns E o Qp, P ns E o ZQP, E o QZ(Q+P ns )P and P ns E o DED and variations thereof.
In order to further illustrate the advantages of the invention, the following examples are given and are not to be interpreted as limiting the invention in any manner.
EXAMPLE 1
A softwoood kraft pulp (10 grams based on oven dry weight of pulp) of Kappa number 16.1 and viscosity of 19.7 centipoise was initially treated with the disodium salt of ethylenediaminetetraacetic acid (ETDA) to remove metals. The pulp was then treated with monoperoxysulfate (2.5 wt. % as H 2 O 2 based on the oven dried weight of wood fibers) at 10 wt. % consistency. The pulp was then washed twice with distilled water and subjected to an alkaline extraction treatment with 2.5 wt. % NaOH at 10 wt. % consistency and 80° C. for 1 hour.
In samples numbered 1-8, the bleaching step was conducted under substantially neutral pH conditions by maintaining about 12-22.5 wt. % sodium bicarbonate in the bleaching solution.
For comparison purposes, samples numbered 9-15 illustrate acidic monoperoxysulfate bleaching at a pH ranging from about 2 to just above about 7 and samples numbered 16-22 illustrate alkaline monoperoxysulfate bleaching at a pH ranging from above about 8.0 to 12.7. The results are given below in Table 1 and illustrated in FIGS. 1 and 2.
TABLE 1__________________________________________________________________________Initial Final Temp. Time Viscosity Delignification SelectivitySample #pH pH (°C.) (hrs) Kappa No. (cP) (wt. %) (▴K/▴V)__________________________________________________________________________Neutral 1 7.13 6.78 50 3.0 6.07 16.41 62.37 3.05 2 7.15 7.00 50 3.0 5.47 16.91 66.10 3.79 3 7.29 7.15 50 2.5 5.92 16.40 63.30 3.08 4 7.39 7.28 50 2.5 5.77 16.56 64.24 3.28 5 7.47 7.44 50 2.5 6.07 17.29 62.37 4.14 6 7.24 7.13 50 2.5 6.07 18.58 62.37 8.82 7 8.29 7.57 50 2.5 6.52 18.24 59.58 6.50 8 8.65 7.65 50 2.5 6.37 18.97 60.51 13.11Acidic 9 2.08 1.97 70 6.0 3.97 6.49 75.41 0.9210 6.33 2.45 70 6.0 3.97 9.04 75.41 1.1811 6.75 2.77 70 5.0 4.87 11.18 69.82 1.3212 6.98 3.19 70 5.0 5.55 12.34 65.63 1.4413 6.95 3.69 70 5.0 5.62 12.32 65.17 1.4214 7.05 5.62 70 4.0 5.77 13.56 64.24 1.6815 7.23 6.81 70 4.0 6.07 13.73 62.37 1.68Alkaline16 8.83 7.98 50 2.5 6.82 17.50 57.72 4.1917 9.06 8.61 50 2.5 7.13 18.20 55.86 5.9518 9.43 9.36 50 2.5 6.52 17.43 59.58 4.2019 12.1 9.8 50 2.5 5.77 15.58 64.25 2.5020 12.4 11.1 50 2.5 4.87 12.11 69.83 1.4821 12.6 12.0 50 2.5 4.72 11.24 70.76 1.3522 12.7 12.5 50 2.5 4.57 9.78 71.69 1.16__________________________________________________________________________
As illustrated in Table 1, the selectivity has neutral monoperoxysulfate bleaching is significantly higher than the selectivity for ether acidic or alkaline monoperoxysulfate bleaching at similar delignification degrees. The relatively high selectivities of samples 16-18 under alkaline conditions are achieved only at lower delignification degrees. The improvements in delignification degree and selectivity for neutral monoperoxysulfate bleaching are obtained with relatively negligible pulp viscosity decrease as illustrated by Samples 1-8 compared to Samples 9-22.
As shown in FIG. 1, there is a selectivity spike around pH 7 as illustrated by curve B and much lower selectivities at pH values above and below 7 as illustrated by curves A and C.
FIG. 2 illustrates the affect the treatment pH has on the Kappa number and viscosity of the pulp over a pH range of 2 to 14. There is a negligible loss in viscosity between pH 7 to 9. Between pH 8 to 9 the reactivity is somewhat lower resulting in a small change in Kappa number. Under acidic conditions, the reactivity is also lower and hence higher temperatures are required which also lead to a loss in viscosity. Likewise, at higher pH values, the viscosity and selectivity are lower.
EXAMPLE 2
In the next series of samples, the effect of the strength of neutral monoperoxysulfate on pulp is illustrated. For this example, the pulp was again a softwood kraft pulp having an initial Kappa number of 17.5 and an initial viscosity of 20.95 centipoise. The bleaching stage (P ns ) was conducted at an initial pH of about 7.3 and a final pH of about 7.1 at 50° C. and at 10 wt. % consistency followed by an oxygen reinforced extraction stage using 2.5 wt. % NaOH and 0.13 wt. % MgSO 4 at a temperature of 80° C. for 1 hour and at 10 wt. % consistency. The oxygen pressure during the extraction stage was initially 74.7 psia and was incrementally decreased (10 psi/10 min.) to 14.7 psia over the 1 hour extraction period. The results of this test are given in Table 2. In Sample 1, no monoperoxysulfate was used.
TABLE 2______________________________________ P.sub.ns as H.sub.2 O.sub.2 Kappa Viscosity Delignification SelectivitySample # (wt. %).sup.1. No. (cP) (wt. %) (▴K/.tangle-solidup .V)______________________________________1 -- 11.71 18.23 33.09 2.132 0.50 8.78 18.80 49.83 4.063 0.75 7.65 18.36 56.29 3.804 1.00 7.28 18.70 58.40 4.54______________________________________ .sup.1 The weight percent is based on the oven dried weight of wood fibers.
As illustrated in Table 2, as the amount of monoperoxysulfate is increased, there is an increase in the degree of delignification. The selectivity remains good when a neutral pH is maintained throughout the bleaching stage even at high degrees of delignification. As the degree of delignification is intensified, the selectivity increases at the neutral pH, a result which was totally unexpected.
In accordance with the present invention, neutral monoperoxysulfate bleaching, even at relatively low monoperoxysulfate concentrations, may achieve high degrees of delignification with high selectivities when used in combination with an oxygen delignification stage. To achieve the same degree of delignification with the process of U.S. Pat. No. 5,091,054 typically requires much higher oxone concentrations.
While the foregoing description and examples relate particularly to chlorine-free bleaching stages, any combination of chlorine containing and neutral monoperoxysulfate bleaching stages may also be used. Accordingly, variations of the invention by those skilled in the art are within the spirit and scope of the appended claims. | An elementally chlorine-free method for the delignification and bleaching of pulp which involves the use of a neutral monoperoxysulfate bleaching step to delignify and thus brighten the pulp. The process achieves good selectivities above about 3 even at high delignification degrees of 60% or greater. | 3 |
BACKGROUND OF THE INVENTION
‘Robson’ is a product of a breeding-program which had the objective of creating new chrysanthemum cultivars with an anemone type flower, a 7 week response and a medium plant height. The new plant of the present invention comprises a new and distinct cultivar of Chrysanthemum plant. ‘Robson’ is a seedling from a cross in a breeding program maintained under the control of inventor. The female parent is #90.602—unpatented—, an unnamed seedling not available to inventor for description. The male parent is unknown, being a mixed pollation of a group of male parents. The new and distinct cultivar was discovered and selected as a flowering plant within the progeny of the stated cross by Rob Noodelijk in a controlled environment (greenhouse) in Rijsenhout, Holland in May 1995. The first act of asexual reproduction of ‘Robson’ was accomplished when vegetative cuttings were taken from the initial selection in August 1995 in a controlled environment in Rijsenhout, Holland.
SUMMARY OF THE INVENTION
The present invention is a new and distinct variety of chrysanthemum bearing medium sized blooms with red ray-florets and a greyed-yellow center.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention of a new and distinct variety of chrysanthemum is shown in the accompanying drawings, the color being as nearly true as possible with color photographs of this type.
FIG. 1 shows a plant of the cultivar in full bloom.
FIG. 2 shows the various stages of bloom of the new cultivar.
FIG. 3 shows the foliage of the new cultivar
DESCRIPTION OF THE INVENTION
This new variety of chrysanthemum is of the botanical classification Dendranthema grandiflora . The observations and measurements were gathered from plants grown in a greenhouse in Rijsenhout Holland in a photo-periodic controlled crop under conditions generally used in commercial practice. The photo-periodic response time in this crop was 48 days after an average of eight long days. After this long day period to flowering growth retardants were applied 6 times in an average dose of 1.5 gram/liter water. This new variety produces medium sized blooms with red ray-florets and a yellow-greyed center blooming on the plant for 5 weeks. This new variety of chrysanthemum has been found to retain its distinctive characteristics throughout successive ppropagations however the phenotype may vary significantly with variations in environment such as light intensity and temperature. To show the phenotype as described ‘Robson’ can be planted without assimilation lightning (high pressure sodium lamps) between week 50 and week 40 of the next year under greenhouse conditions in Holland. With assimilation lightning (minimum level 2500 lux) it can be planted year round under greenhouse conditions in Holland.
From the cultivars known to inventor the most similar existing cultivar in comparison to ‘Robson’ is ‘Jasper’ (U.S. Plant Pat. No. 9,155). When ‘Jasper’ and ‘Robson’ are being compared the following differences are noticed (in general terms): The differences of ‘Jasper’ and ‘Robson’ are: (1) Response time. (2) Habit of the plant and (3) Flower color.
The following is a description of the plant and characteristics that distinguish ‘Robson’ as a new and distinct variety.
The color designations are taken from the plant itself. Accordingly, any discrepancies between the color designations and the colors depicted in the photographs are due to photographic tolerances.
Table 1: Botanical Description of CULTIVAR ‘Robson’
Bud:
Size.— Medium; cross-section 1.1 cm, height 1.0 cm.
Outside color.— Red-purple 42D.
Involucral bracts.— 2 rows, length 8 mm., width 3 mm.
Involucral bracts among disc - florets.— Not present.
Involucral bracts color.— Green 138 B.
Bloom:
Type.— Anemone.
Height.— Medium high.
Size.— Medium.
Fully expanded.— 5.5-6.0 cm.
Borne ( number of blooms per branch ).—Approx. 5 blooms per branch.
Performance on the plant.— 5 weeks.
Seeds.— Not produced.
Fragrance.— Typical chrysanthemum.
Color:
Center of the flower ( disc - florets ).—Immature in the center 143B, to the outside 183B with 162A at the apex. Mature 44A with 162A at the apex.
Color of upper surface of the majority of the ray - florets.— Red 44B.
Color of the lower surface of the majority of the ray - florets.— Greyed-red 178D.
Tonality from distance.— A pot mum with red anemone flowers and a yellow-greyed center.
Discoloration to color.— Greyed-red 178D.
Ray florets:
Texture.— Upper and under side smooth.
Number.— 20-22.
Cross - section.— Convex.
Longitudinal axis of majority.— Reflexing.
Margin.— Entire.
Length of corolla tube.— Short.
Ray - floret length.— 2.5 cm.
Ray - floret width.— 1.0 cm.
Ratio length/width.— Low.
Shape of tip.— Retuse and acute.
Disc florets:
Disc diameter.— Large (2.0-2.5 cm).
Distribution of disc florets.— Numerous and clearly visible at all stages of flowering.
Type.— Petaloid.
Color.— Greyed-red 183B with greyed-yellow 162A at the apex.
Receptacle shape.— Conical raised.
Reproductive organs:
Stamen ( present in disc florets only ).—Yellow-green 144A, thin, 2 mm in length.
Pollen.— No pollen.
Pollen color.— Not applicable.
Styles ( present in both ray and disc florets ).—Yellow-green 144A, thin.
Style length.— 4 mm.
Stigmas.— Yellow-green 144A.
Stigma width.— 2 mm.
Ovaries.— Enclosed in calyx.
Plant:
Form.— A pot mum meant for indoor use.
Growth habit.— Spreading.
Growth rate.— Slow.
Height.— 19.0-22.0 cm.
Width.— 25.0 cm.
Stem color.— Yellow-green 144A.
Stem strength.— Strong.
Stem brittleness.— Absent.
Stem anthocyanin coloration.— Present, a slight tint of greyed-purple 183 D.
Length of lateral branch.— From top to bottom 12.0 cm.
Lateral branch color.— Green 138 B.
Lateral branch, attachment.— Not strong, not weak.
Branching ( average number of lateral branches ).—Normal with 3-4 breaks after pinching.
Peduncle length.— 3.0-3.5 cm.
Peduncle color.— Green 138 B.
Flowering response ( photo - periodic controlled crop, no natural growing ).—48 Days.
Foliage:
Color.— Upper side green 137 A. Under side green 138 A.
Size.— Medium, length 5.5 cm, width 5.0 cm.
Quantity (number per lateral branch): 5-8
Shape.— Ovate and pinnately lobed.
Texture upper side.— Fleshy.
Texture under side.— Pubescent.
Ribs and veins upper side.— Ribs and veins well developed.
Ribs and veins upper side.— Ribs and veins well developed.
Venation arrangement.— Palmate.
Shape of the margin.— Crenated.
Shape of base of sinus between lateral lobes.— Acute.
Margin of sinus between lateral lobes.— Converging.
Shape of base.— Truncate.
Apex.— Mucronate.
Age.— 56 days.
TABLE 2
Differences with the comparison varieties
‘Robson’
‘Jasper’
Response time
48 days
54 days
Habit
Compact and spreading
Semi upright
Flower color
Intense red
Red-bronze | A chrysanthemum plant named ‘Robson’ characterized by its medium sized bloom with red ray-florets and a greyed-yellow center. | 0 |
FIELD OF INVENTION
[0001] The present invention relates to heart valve repair, in particular mitral valve repair.
STATE OF THE ART
[0002] Mitral valve regurgitation (MR) is an abnormal, backwards flow of blood in the heart through the mitral valve. The mitral valve is one of 4 valves in the heart. It is located between the upper left heart chamber (left atrium) and lower left heart chamber (left ventricle). The mitral valve has 2 flaps, called leaflets, which open and close like a door with each heartbeat and normally let blood flow in just one direction through the heart. If the mitral valve does not close properly, some of the blood from the left ventricle is forced back up (regurgitated) into the left atrium instead of flowing out to the rest of the body. The added workload on the heart and increased blood pressure in the lungs may eventually cause problems. Although many diseases can damage the mitral valve and cause regurgitation mitral valve prolapse is the most frequent abnormality affecting 2.5% of the population. From that, 5 to 10% will develop severe regurgitation being the most common cause of mitral insufficiency in USA. Mitral valve prolapse occurs when the mitral valve leaflet tissue is deformed and elongated so that the leaflets do not come together normally leading to a MR. In severe cases, the left ventricle enlarges and functions less efficiently, the left atrium progressively enlarges, abnormal heart rhythms occur, and the blood pressure in the pulmonary artery increases leading to a pulmonary hypertension. Over time, these changes become irreversible as the signs and symptoms of heart failure develop.
[0003] Ischemic MR is a complication of coronary heart disease; it primarily occurs in patients with a prior myocardial infarction (MI). MR may also occur with acute ischemia, a setting in which the MR typically resolves after the ischemia resolves. Following an MI, the MR is usually due to infarction with permanent damage to the papillary muscle or adjacent myocardium; in such patients, MR may become more severe with adverse remodeling of the left ventricle or subsequent ischemia.
[0004] The need for treatment of MR depends upon the presence and severity of symptoms, the cause of the MR, and the presence of other underlying medical conditions. Medical and surgical therapies are available to treat people with MR. The treatment of choice for most people with severe chronic MR is surgical repair or replacement of the mitral valve.
[0005] The mortality and long term results depends directly of the preoperative clinical condition. In patients with impaired left ventricular function, pulmonary hypertension (very common in mitral regurgitation) the surgical risk can be over 10%. The clinical relevance to find alternative approaches, which do not involve cutting the sternum is enormous.
[0006] There is strong scientific evidences confirming that the repair instead replacement of the mitral valve is the treatment of choice mainly because its lower operative mortality and better long-term survival. Among the different techniques used to treat mitral prolapsed, the simplest and effective consists in resecting the prolapsed segment trough a triangular resection. This technique can be used in all types of prolapsed posterior leaflets an in many prolapsed anterior leaflets. This technique can be also used to treat ischemic MR.
[0007] International patent application WO 2006/007576 discloses a system for percutaneous tissue repair. This device may also be used for mitral valve repair. The tissue is grasped, plicated and then sewed.
[0008] With the system disclosed in WO 2006/007576 it is however not possible to carry out a triangular resection.
GENERAL DESCRIPTION OF THE INVENTION
[0009] The present invention provides a new and original solution to repair a heart valve, in particular a mitral valve, in a percutaneous manner and, preferably, based on a “triangular resection” technique.
[0010] The invention more precisely concerns a medical device and a surgical method for using said device as defined in the claims.
[0011] The method according to the invention can be applied to the posterior leaflets (P 1 , P 2 and P 3 ) as well as the anterior leaflet. It can be also applied to treat prolapsed aortic valves, and prolapsed tricuspid valves.
[0012] The method comprises the triangular plication of the prolapsed portion of the leaflet, the pinching of the plicated portion and, preferably, the resection of the excess of leaflet tissue.
[0013] The method is based on the use of a single catheter (however two catheters could also be used from different access, namely transatrial, transapical etc.) that is inserted through a trans-septal access via the femoral vein or a peripheral vein or a transatrial access or a transapical access via a small thoracotomy incision.
DETAILED DESCRIPTION OF THE INVENTION
[0014] To better disclose the invention, some illustrated but non-limiting examples are provided in the present chapter.
[0015] FIG. 1 illustrates a first example of a device according to the invention
[0016] FIG. 2 illustrates the plicating tweezer of FIG. 1 in an open configuration and forming an angle of 25° with respect to the tweezer main axis.
[0017] FIG. 3 illustrates the plicating tweezer of FIG. 1 in an open configuration and forming an angle of 90° with respect to the tweezer main axis.
[0018] FIG. 4 illustrates the plicating tweezer of FIG. 1 in an closed configuration and forming an angle of 25° with respect to the tweezer main axis.
[0019] FIGS. 5 a 01 to 5 a 16 show different steps of one surgical method according to the invention, taken from a first point of view.
[0020] FIGS. 5 b 01 to 5 b 16 show different steps of the method illustrated in FIGS. 5 a 01 to 5 a 16 , but taken from another point of view.
NUMERICAL REFERENCES USED IN THE FIGURES
[0000]
1 Grasping tweezer
2 Plicating tweezer
3 Tissue prolapsed portion or tissue rim
4 First flap
5 Second flap
6 Central shaft
7 First long segment of first flap
8 Second long segment of first flap
9 Short segment of first flap
10 First long segment of second flap
11 Second long segment of second flap
12 Short segment of second flap
13 Mesh
14 Catheter
15 Grasping tweezer main axis
16 Plicating tweezer main axis
17 Mitral valve
18 Plicating tweezer rotation axis
[0039] FIG. 1 illustrates a mitral valve 17 having a leaflet containing a prolapsed portion 3 .
[0040] The device comprises a tissue grasping tweezer 1 and a plicating tweezer 2 , both tweezers 1 , 2 are moved to the operating field within a single catheter 14 .
[0041] The grasping tweezer 1 forms a variable angle with respect to the grasping tweezer main axis 15 .
[0042] The plicating tweezer 2 is made of a central shaft 6 around which two triangular shaped flaps 4 , 5 can rotate. Each flap 4 , 5 comprises two main segments 7 , 8 , 10 , 11 which, together with the central shaft 6 , form a triangular element. All the segments 7 - 12 are furthermore covered by a mesh 13 .
[0043] In addition, or in replacement to the mesh 13 , the segments 7 - 12 may be covered by a metallic layer, a synthetic layer or a biological tissue.
[0044] The catheter 14 is inserted at the level of the diseased valve 17 in correspondence of the prolapsed portion of the leaflet 3 ( FIG. 5 a 01 , FIG. 5 a 02 , FIG. 5 b 01 and FIG. 5 b 02 ). The grasping tweezer 1 is extracted from the catheter 14 and under fluoroscopy and Echo 3D guidance is remotely actuated by the operator in a way to grab the central portion of the prolapsed portion 3 for an extension going from the free edge towards the mitral annulus (typically a length ranging from 0.5 to 2.5 cm) ( FIGS. 5 a 03 to a 08 and FIGS. 5 b 03 to b 08 ).
[0045] The plicating tweezer 2 is then extracted from the catheter 14 , rotated around an axis 18 , opened and placed parallel to an ideal valve plan, in touch with the prolapsed portion 3 ( FIGS. 5 a 09 to a 12 and FIGS. 5 b 09 to b 12 ).
[0046] When the device is stable the grasping tweezer 1 , still grabbing the prolapsed portion 3 , is moved slightly upward creating a tensioned flap corresponding to the prolapsed portion 3 . In this setting the plicating tweezer 2 is closed, over the grasping tweezer 1 , to plicate and pinching triangular shaped prolapsed portion 3 ( FIG. 5 a 13 and FIG. 5 b 13 ).
[0047] At this stage, before to proceed cutting out the prolapsed portion 3 , the online control with an Echo 2D or better 3D may confirm that the residual regurgitation is negligible or eliminated.
[0048] If the hemodynamic conditions of the mitral valve 17 are considered suboptimal the procedure can be repeated retracting the plicating tweezer 2 and using the grasping tweezer 1 to pinch more or less leaflet tissue or to slightly change position to better pinch the prolapsed portion 3 . When the grasping tweezer 1 pinches the leaflet again the procedure can be allover repeated.
[0049] The plicating tweezer 2 , when open, has a polygonal shape ( FIG. 5 a 11 ) made by a plurality of segments 6 - 12 which substantially form two triangular frames hinged at level of the central shaft 6 . More precisely, each substantial triangular frame is formed by three long segments 6 - 8 & 6 , 10 , 11 (that form the general triangular shape) and one short segment 9 , 12 . The shape and dimensions of the triangular frames can be variable in order to treat a different degree of leaflet prolapse. A thin mesh of tissue 13 made of biological, polymeric or metallic material covers the triangular frames. The purpose of the mesh coverage is to avoid the accidental embolization of blood clots, calcific fragments or leaflet's portions during the transcatheter mitral repair procedure.
[0050] Once a satisfactory result is reached the arms of the plicating tweezer 2 are closed over the folded prolapsed leaflet 3 . The flap sides 8 , 11 of the plicating tweezer 2 which are in contact with the tissue can deliver a series of staples, stitches, thermal treatment, radiofrequency, cryo-therapy treatment or any other system to fix together the two portions of the prolapsed leaflet 3 . In alternative constructive solution the portions of the leaflet could be glued together by injecting glue, polymers or any other biocompatible glue material through the arms of the tweezer ( FIG. 5 a 12 , a 13 and FIG. 5 b 12 , b 13 ).
[0051] The pinched leaflet portion will be on the atrial side however the repair procedure could be also performed upside down in a way that the pinched portion of the leaflet is oriented toward the ventricle and placed below the valve plane. This is useful especially, but not exclusively, in patients with complete flail (complete chordae rupture).
[0052] The procedure can be completed with the resection of the plicated and pinched portion in both the above-described procedural situations. The flap sides 8 , 11 of the plicating tweezer 2 which are in contact with the tissue are equipped with a system making a triple function. One is aimed at locking the base line of the plicated, triangular shape, portion of the leaflet, the second one to deliver staples or stitches and the third one at cutting the plicated leaflet portion just above the suture line ( FIG. 5 a 14 e FIG. 5 b 14 ).
[0053] At the end of the procedure the arms of the plicating tweezer 2 are maintained closed over the leaflet tissue fragment and retrieved into the catheter together with the first tweezer ( FIG. 5 a 15 e b 15 ).
[0054] The procedure is completed when the entire catheter is fully retrieved out of the patient ( FIG. 5 a 16 e b 16 ).
[0055] Both tweezers 1 , 2 can be realized with different materials including various metals alloys such as Nitinol, Stainless steel, Cobalt-Chromium or plastic polymers. The articulation and the remote control of the tweezers can be realized adopting several mechanical, pneumatic, hydraulic or electrical solutions also using memory shape alloys such as the Nitinol. The arms of the tweezers 1 , 2 can be straight or curved with different length depending the final adopted solution.
[0056] One way to perform the “plication” is achieved with a surgical stapler together with surgical staples. The staple line may be straight, curved or circular. The instruments may be used in either open or thoracoscopic surgery or full transcatheter, and different instruments can be used for each application. Transcatheter staplers must be longer, thinner, and may be articulated to allow for access from the peripheral veins or arteries.
[0057] Some device can incorporate a knife, to complete excision of the prolapsed segment of the mitral leaflet and anastomosis in a single operation.
[0058] The surgical staples can be made of titanium, namely a material that induces less reaction with the immune system and, being non-ferrous, does not interfere significantly with MRI scanners. Synthetic absorbable or non-absorbable materials could also be used.
[0059] The invention is of course not limited to the device presented in the previous example. The device according to the invention may be used for plication only, i.e. without removal of the prolapsed part of the leaflet. | Medical device for transcatheter heart valve repair comprising a grasping tweezer ( 1 ) and a plicating tweezer ( 2 ), said grasping tweezer ( 1 ) being adapted to grasp a leaflet rim ( 3 ) and said plicating tweezer ( 2 ) comprising two rotatable flaps ( 4,5 ) and a central shaft ( 6 ) around which said flaps ( 4,5 ) may rotate in a “butterfly manner”, in such a way that the plicating tweezer ( 2 ) may adopt a closed or an open configuration. The invention also relates to a method for using this medical device. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
The present application is related to application Ser. Nos.: 068,587, filed June 30, 1987 and 050,360, filed May 18, 1987.
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus for use with a sewing machine to cut a chain of stitches, trailing from a sewn garment and hold the cut chain in a predetermined location so as to be positioned to be incorporated into the leading portion of the seam of the next garment to be sewn.
Sewing machines that form seams utilizing chain stitches on a succession of pieces of material with the seam being continued into the area intermediate the pieces of material, are well-known. With seams of this type, means are provided for detaching the pieces of material one from the other by appropriate automatic chain-cutting devices after the sewn pieces have been caused to travel beyond the needle and the presser foot of the machine.
By cutting the chain of stitches with these devices, one portion of minimal length remains attached to the stitched piece of material and the other being connected to the throat plate is manipulated to a position forwardly of the needle so that it can be incorporated into the initial portion of the seam that will be formed on the next piece of material or workpiece. This procedure prevents a slackening of the seam's initial stitches which would give the leading edge of the workpiece an undesirable appearance.
The known devices for performing this function include a chain-cutting device disposed adjacent the stitch finger of the throat plate which co-operates with a chain-orienting device and gripper apparatus located forwardly the needle and usually adjacent the forward portion of the throat plate.
These apparatii suffer from the disadvantages that, because the portion of the chain to be sewn onto the next garment is located on the upper surface of the throat plate intermediate the needle hole, the gripping apparatus is frequently accidentally displaced while positioning the next workpiece in the sewing area.
The material to be sewn interferes with the chain, preventing the proper insertion of the latter into the new seam being sewn, due to the pressure and friction of the piece of material of the chain which tend to dislodge it from the gripping apparatus and move it toward the trimmer knife of the machine that is adjacently disposed, thereby hindering subsequent handling of the chain.
The following patents generally relate to this subject matter: U.S. Pat. No. 3,490,403, U.S. Pat. No. 4,453,481, U.S. Pat. No. 4,599,960, U.S. Pat. No. 4,599,961, U.S. Pat. No. 4,303,030, U.S. Pat. No. 4,187,793, U.S. Pat. No. 4,038,933, U.S. Pat. No. 4,149,478, U.S. Pat. No. 4,220,105, U.S. Pat. No. 3,541,984, U.S. Pat. No. 3,698,336, and British application 2,058,858.
SUMMARY OF THE INVENTION
A principal feature of the present invention is the provision of an improved sewing machine.
The sewing machine has an apparatus for cutting and positioning a chain of stitches for stitching onto material in the machine having a needle and a throat plate, comprising, a cutting knife adapted to sever the chain of stitches after the chain has been sewn onto the material, positioning means adapted to move the severed chain to a position forwardly of the needle, and gripping means adapted to grasp the severed chain.
A feature of the present invention is that the gripping means is normally positioned below the throat plate of the sewing machine.
Another feature of the invention is that the gripping means rises above the throat plate to receive and grasp the severed chain.
Yet another feature of the invention is that the severed chain is grasped below the level of the throat plate.
A further feature of the invention is that the chain is grasped in a taut configuration.
Still another feature of the invention is that the severed chain is grasped with varying forces.
Further features will become more fully apparent in the following description of the embodiments of this invention and from the appended claims.
DESCRIPTION OF THE DRAWINGS
In the drawings
FIG. 1 is a schematic perspective view of an embodiment of a sewing machine of the present invention;
FIGS. 2-5 illustrate the cycle of operation of the machine of FIG. 1;
FIG. 6 is a side elevational view, partly broken away, of another embodiment of gripping apparatus for the sewing machine of FIG. 1;
FIG. 7 is a fragmentary top plan view of the gripping apparatus of FIG. 6;
FIGS. 8-12 are fragmentary perspective views showing operation of the gripping apparatus of FIGS. 6 and 7; and
FIG. 13 is a fragmentary plan view of a fabric stitched with the sewing machine of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
As the general construction and operation of a sewing machine, which may be of Federal Stitch Type 504, to which the present invention is applicable, is wellknown and familiar to those conversant in the art, and as the invention is primarily concerned with a device for positioning and gripping a chain of stitches for incorporation into the initial stitches of a new seam, it is only considered necessary here to illustrate and describe those parts which are directly concerned with a preferred form of the invention.
With reference to FIGS. 1-5, the sewing machine has a throat plate 20 with a stitch finger or tongue 23 positioned adjacent a reciprocating needle 15, and a presser foot 30. The sewing machine has a movable clamp 21 adjacent the throat plate comprising a material feed mechanism 19, and a cutter 13 along with a blower 14 for positioning a chain 18 of stitches. The sewing machine has an associated first light emitter 12a and light detector 12b, and a second light emitter 22a and light detector 22b.
The sewing machine has a gripping apparatus 16 having a hook member 17 movable between a first position above the throat plate 20 and a second position beneath the throat plate 20. The gripping apparatus 16 has a pneumatic cylinder 24 connected to the hook member 17. The gripping apparatus 16 has an extension 25 which slides in a slot 26 of the member 27 of the gripping apparatus 16. In a lower position of the hook member 17, the extension 25 abuts against the member 27, and the member 27 and hook member 17 are withdrawn beneath the throat plate 20 against the biasing of a spring 28. The spring 28 biases the member 27 to an upper initial position when the hook member 17 starts its upward motion.
As shown in FIGS. 1 and 2, after the chain 10 is sewn onto the material 11, the clamp 21 moves away from the needle 15 and presser foot 30 and pulls the threads off the stitch finger or tongue 23. Light is emitted by light emitter 12a, and light detector 12b senses a change of reflectivity from a lower surface, such that the detector 12b senses the end of the material in response to which the cutter 13 severs the chain 10. The positioning means, in the form of a blower 14, directs a stream of air onto the severed chain to blow it back forwardly of the needle 15, as shown by the phantom chain 18. Alternatively, the machine may have a plurality of blowers to sequentially move the chain forwardly of the needle. The gripping means or apparatus 16 is activated, and the hook member 17 rises to hook around the severed chain 18.
As shown in FIG. 3, the cutter 13 opens with the material feed mechanism 19 moving the sewn material to a conveyor (not shown).
The blower 14 shuts off and is raised. The hook member 17 returns to below the throat plate 20, clamping the severed chain in the gripping means 16.
As shown in FIG. 4, the clamp 21 opens, and the released garment is removed by the conveyor, with the clamp 21 returning to its starting position forwardly of the needle 15. Meanwhile, the gripping means 16 moves further below the throat plate 20, tensioning the chain 18. Light is emitted by light emitter 22a, and light detector 22b senses a change of reflectivity from a lower surface. When material is sensed by the detector 22b, the clamp 21 closes and the material is fed to the sewing machine, while the chain 18 is held in tension by the gripping means 16 for the initial stitching of the seam, to prevent slackening of the seam's initial stitches which would give the leading edge of the material an undesirable appearance.
As the material 11 is moved across under the needle 15 by the material feed mechanism 19, the end of the chain is pulled from the gripping means 16 and the chain 18 is sewn into the seam, and the cycle is repeated. The resulting sewn fabric is shown in FIG. 13 in which the chain 18 is shown beneath the seaming or overedge stitches 29.
The gripping means 16 is operated by a single pneumatic cylinder 24 which is directly connected to the hook member 17. When the piston of the cylinder 24 pushes the hook member 17 upwardly, as shown in FIG. 2, an extension 25 slides in a slot 26 of member 27 of the gripping means. Upon the hook member 17 being withdrawn, as shown in FIG. 3, the extension 25 slides in the slot 26 to then abut against the member 27, whereby both the member 27 and the hook member 17 are withdrawn further below the throat pate 20 against the biasing force of the spring 28, as shown in FIG. 4. Upon the hook member 17 starting its upward motion, the spring 28 returns the member 27 to its initial position below the throat plate 20.
Thus, the present invention, at all times, provides an apparatus for the cutting and the positioning of a chain stitch which ameliorates the problems of the prior art, by providing a mechanical gripping means 16 which holds the severed chain below the level of the throat plate, with the gripping means 16 being movable between positions below and above the throat plate 20.
In an alternative form, the light emitter 12a and light detector 12b may be omitted, and a time delay may be initiated or stitches may be counted after light detector 22b senses the material in order to activate the cutter 13.
Another embodiment of the gripping apparatus 16 is shown in FIGS. 6-12, with like parts being designated by the addition of 100 to the reference numeral in FIGS. 1-5. With reference to FIGS. 6-8, the gripping apparatus 116 has an elongated lower plate 40, an elongated nipper 42, and an elongated guide 44.
The plate 40 has a forward beveled edge 46, a first elongated slot 48 with opposed first and second ends 50 and 52, a second elongated slot 54 with first and second ends 56 and 58, and an elongated third slot 60 with first and second ends 62 and 64. The plate 40 also has a rearward end 66. The plate 40 has an upwardly directed pin 68 for a purpose which will be described below.
The gripping apparatus 16 has a stationary member 70 having cavity 72 facing the plate 40. A helical spring 74 is received in the cavity 72 and extends between one end 76 of the cavity 72 and the pin 68 of plate 40. In this configuration, the spring 74 is compressed and thus biases the plate 40 forwardly through the pin 68. The stationary member 70 has a rear stop 78 which bears against rearward end 66 of the plate 40 in this configuration of the gripping apparatus 16. The stationary member 70 has an elongated slot 80 extending therethrough and communicating with the second slot 54 of the plate 40. The stationary member 70 also has a forwardly directed cam 82 for a purpose which will be described below. The cam 82 is slidable in the stationary member 70, and may be secured at a desired position by a screw 83.
The gripping apparatus 116 has a movable retaining member 84 connected to and driven by the piston 86 of a cylinder 88. The retaining member 84 has a depending pin 90 extending through slot 80 of stationary member 70 and having a washer 92 received in the second slot 54 of plate 40. The retaining member 84 has a pair of screws 94 and 96 which fixedly secure rearward ends of the resilient nipper 42 and resilient guide 44 to the retaining member 84. The retaining member 84 has a forwardly directed flange 98 having a threaded aperture 100 to receive a screw 102 containing a nut 104 above the flange 98. The outer end of screw 102 bears upon the nipper 42 to bias the nipper 42 toward the plate 40. The screw 102 and nut 104 are adjustable in flange 98, such that the screw 102 may exert an adjustable bias against nipper 42 to accommodate different diameter sizes of threads.
The nipper 42 has an elongated bar 105 connected to a forward end 106 having an outwardly directed finger 108, with the forward end 106 being located near or against the plate 40.
The guide 44 has a forward curved end portion 110 spaced from the finger 108 of the nipper 42 to define a space 112 between the nipper finger 108 and end portion 110 of the guide 44. An outer end 114 of the guide 44 is located above the bar 105 of the nipper 42. In the configuration shown, the guide 44 bears against the cam 82 which raises the end 114 of the guide 44 from the nipper 42 for a purpose which will be described below. When the nipper 42 and guide 44 are moved forwardly by the retaining member 84, as will be described below, the guide 44 becomes disengaged from the cam 82 causing the end 114 of resilient guide 44 to engage against the bar 105 of nipper 42 causing further bias of the nipper 42 against the plate 40.
In operation, prior to severing the chain 110, the plate 40, nipper 42, and guide 44 are all located beneath the throat plate 20, as shown in FIG. 8, with the forward end of the nipper 42 located adjacent the forward end of the plate 40. With reference to FIGS. 6, 7, and 9, shortly before or after the chain 110 is severed, the cylinder 88 is activated causing forward movement of the retaining member 84 and retained nipper 42 and guide 44. At the same time, the pin 90 moves forwardly in the slot 80 of the stationary member 70, and the moving washer 92 permits forward movement of the spring biased plate 40 to a location with the beveled edge 46 located adjacent the throat plate 20. At this time, the screw 73 of stationary member 70 strikes the second end 52 of first slot 48 and the screw 75 of stationary member 70 strikes the second end 64 of third slot 60, thus preventing further forward movement of the plate 40 past the throat plate 20. However, with reference to FIGS. 6, 7, and 10, the cylinder 88 continues to drive the retaining member 84, thus moving the retained nipper 42 and guide 44 above the throat plate 20, while the pin 90 leaves the second end 58 of the second slot 54, since the plate 40 is no longer free to move forwardly past the throat plate 20.
In this configuration of the gripping apparatus 16, the severed chain 118 is first moved to one side of the needle by a first blower 130, as shown in FIG. 10, and is then moved by the blower 114 into the space 112 between the nipper 42 and guide 44, with the curved guide 44 directing the chain 118 into the space 112, as shown in FIG. 11.
At this time, the cylinder 88 begins to retract the nipper 42 and guide 44 until the forward end of the nipper 42 is located adjacent the forward end of the plate 40 at the level of the throat plate 20. The severed chain 118 thus becomes caught between the finger 108 of the nipper 42 and the forward portion of the plate 40. Also, at this time, the washer 92 again engages against the second end 58 of second slot 54, and further retraction of the retaining member 84 also causes retraction of the plate 40 along with the nipper 42 and guide 44.
As previously discussed, when the guide 44 leaves the cam 82, the outer end 114 of the guide 44 is biased against the nipper 42 to apply an increased bias to the nipper 42 against the plate 40 in order to draw the chain 118 taut as the nipper 42 and guide 44 move beneath the throat plate 20.
The cylinder continues to retract the nipper 42 and guide 44 beneath the throat plate 20, while driving the plate 40 through pin 90 to the configuration shown in FIG. 12 with the gripping apparatus 116 beneath the throat plate 120, with the chain 118 located in a groove 116 between the throat plate 120 and a conventional fabric cutter 118, and with the plate 40 striking the stop 78. At this time, the guide 44 engages the cam 82, and the end 114 of guide 44 becomes disengaged from the nipper 42 to provide a lessened bias between the nipper 42 and plate 40. Although the chain 118 is drawn taut beneath the top of throat plate 20, the lessened bias of the nipper 42 permits easy removal of the chain 118 from the nipper 42 and plate 40 to prevent distortion of the first few stitches of the next sewn fabric. As previously discussed, the chain 118 is released from the gripping apparatus as the next fabric is sewn over the chain resulting in the sewn fabric of FIG. 13.
The foregoing detailed description is given for clearness of understanding only, and no unnecessary limitations should be understood therefrom, as modifications will be obvious to those skilled in the art. | An apparatus for cutting and positioning a chain of stitches for stitching onto material in a sewing machine having a needle and a throat plate, comprising, a cutting knife adapted to sever the chain of stitches after the chain has been sewn onto the material, a device adapted to move the severed chain to a position forwardly of the needle, and a gripping device adapted to be positioned at a level below the throat plate during sewing of the chain stitches onto the material, and to rise up and grip the thus positioned severed chain, and return to below the level of the throat plate to hold the chain, to effect incorporation of the chain during the initial stitches into the seam being formed. | 3 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the field of vehicles' engines, and more specifically, the present invention is directed to servicing engines.
2. Background
Engine manufacturers highly recommend that engine cooling systems be serviced every 15,000 to 30,000 miles. Lack of proper service can cause engine problems due to the fact that old coolant in the vehicle's radiator system may no longer protect against rust or acids that can lead to a breakdown of the metal and aluminum parts in the engine. Periodic service intervals are recommended to protect the engine against overheating that can be caused by a breakdown of the coolant's protective properties.
To this end, automobile service stations utilize various systems and methods to replace old coolant in the radiator system with new coolant in accordance with the manufacturers' recommendation. Conventional systems, however, suffer from many problems. To mention a few, conventional systems cause coolant drainage and are environmentally hazardous. To prevent coolant drainage, service operators must place a pan under the vehicle to avoid coolant spill. Moreover, the radiator pressure cannot be released prior to removing the radiator cap which can place service operators in danger.
Furthermore, conventional systems require constant operator attention. For example, at the end of the coolant exchange, the operation must end immediately, otherwise the vehicle's coolant continues to be drained, and as a result, the vehicle's engine can overheat and be damaged. Even more, at the completion of the coolant exchange, the conventional systems require the operator to add more coolant manually in order to adjust the level of coolant in the radiator system. To that end, the operator must either prepare a mixture of coolant and water, or prior to starting the coolant exchange process, save some in a separate container. At the end of the coolant exchange, the additional coolant must either be deposited in the service system tank or be added to the radiator system by the operator. Indeed, such methods are extremely labor intensive, unsafe and time consuming.
As another example of the shortcomings, in the existing systems, fluid flow control is achieved via a pressure switch that turns off the fluid flow completely when the system pressure reaches a predetermined level by stopping the system and/or engine and then restarting the system and/or engine when the system pressure falls below a second level. The on-to-off transitions are greatly harmful to the service system and the vehicle's engine.
Accordingly, an intense need exists for apparatus and method for servicing engine cooling systems that can safely and efficiently solve the existing problems in the art.
Further disadvantages of the related art will become apparent to one skilled in the art through comparison of the drawings and specification which follow.
SUMMARY OF THE INVENTION
In accordance with the purpose of the present invention as broadly described herein, there is provided method and apparatus for servicing engine cooling systems.
In particular, in one embodiment, method and apparatus of the present invention includes connecting a service inlet of the apparatus to a system fluid outlet, connecting a service outlet of the apparatus to a system fluid inlet, and pumping out the old fluid from the system through the system outlet and the service inlet, pumping in, simultaneously with the pumping in step, the new fluid from a new fluid tank to the system through the system outlet and the service inlet. In one aspect of the present invention, pumping steps are terminated when new fluid level in the new fluid tank reaches a predetermined low-level.
In another aspect, when new fluid level in the new fluid tank reaches a predetermined low-level, a fluid path between the service inlet and the service outlet is established such that system fluid cycles through the apparatus, but is not drained.
In one aspect of the present invention, the system fluid may be topped off with the new fluid remained, below the low-level mark, in the new fluid tank.
In yet another aspect of the present invention, the service apparatus includes a pressure relief valve coupled to the pressure pump at one end and coupled to an inlet of the new fluid tank at another end, and the relief valve opens, partially or completely, in response to system pressure.
In another separate aspect, the service apparatus vacuums or pumps out the old fluid without replacing it with the new fluid.
Other aspects of the present invention will become apparent with further reference to the drawings and specification, which follow.
BRIEF DESCRIPTION OF DRAWINGS
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate presently preferred embodiments of the invention and, together with the general description given above and the detailed description of the preferred embodiments given below, serve to explain the principles of the invention.
FIG. 1A depicts one embodiment of an engine cooling system service apparatus;
FIG. 1B depicts an example control panel of the engine cooling system service apparatus of FIG. 1A;
FIG. 2 depicts an example flow schematic of the engine cooling system service apparatus of FIG. 1A; and
FIG. 3 depicts an example electrical schematic of the engine cooling system service apparatus of FIG. 1 A.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1A illustrates an exemplary embodiment of an engine cooling system service apparatus 100 of the present invention. As depicted in FIG. 1A, the service apparatus 100 comprises a front control panel 150 . The control panel 150 is shown in more detail in FIG. 1 B.
Referring to FIG. 1B, the control panel includes a fluid filler neck 115 for adding coolant mixture to a reservoir tank 265 (see FIG. 2) of the service apparatus 100 . The control panel 150 further includes a top-off switch 145 that is used to top-off or add coolant to the engine cooling system (not shown) upon completion of the service procedure.
The control panel 150 also includes a three-position mode switch 140 for selecting the service apparatus 100 modes of operation. In one embodiment, the mode switch 140 , when placed in the center position, indicates that the service apparatus 100 is in off or by-pass mode of operation. The mode switch 140 , when placed in the left position, indicates that the service apparatus 100 is in vacuum mode. The mode switch 140 , when placed in the right position, indicates that the service apparatus is in fluid exchange mode.
The control panel 150 includes a low-fluid-level indicator light 110 that illuminates when coolant mixture in the reservoir tank 265 (see FIG. 2) falls below a predetermined low fluid level. The control panel 150 further includes a service-in-progress indicator light 105 that illuminates when the service apparatus 100 is placed in fluid exchange mode. The control panel 150 also includes a pressure gauge 135 that displays fluid pressure in the service apparatus 100 .
Turning back to FIG. 1A, it is shown that the service apparatus 100 also comprises a tank-level indicator 125 that indicates the coolant mixture level in the reservoir tank 265 (see FIG. 2 ). The service apparatus 100 further comprises a used coolant hose (inlet) 120 , a new coolant hose (outlet) 130 , a disposal hose 122 , battery cables 138 , a circuit breaker 136 and a warning alarm 137 . The used coolant hose 120 is used to receive old coolant from the engine's outlet (not shown), and the new coolant hose 130 provides new coolant from the reservoir tank 265 (see FIG. 2) to the engine's inlet (not shown). The disposal hose 122 is used for transferring old coolant to a disposal tank (not shown). The battery cables 138 make it possible to utilize a vehicle's battery to provide power to the service apparatus 100 . The circuit breaker 136 provides circuit protection to the internal circuitry of the service apparatus 100 , as described below. The warning alarm 137 is used to alert the operator of the service apparatus 100 , for example, when the reservoir tank 265 (see FIG. 2) falls below a certain level or becomes empty.
The service apparatus 100 further comprises a flow system 200 and an electrical system 300 , as shown in FIGS. 2 and 3.
To begin a service process of a vehicle's engine cooling system using the service apparatus 100 , the battery cables 138 are connected to the vehicle's battery (not shown). Next, the disposal hose 122 should be inserted in the disposal tank (not shown). As a preferred step, at this point, the used coolant hose 120 should be inserted into the vehicle's overflow radiator tank (not shown). Next, the mode switch 140 should be placed in vacuum mode to evacuate approximately half of the amount of coolant in the vehicle's overflow tank. The mode switch 140 should then be placed in the off position.
In the next step of the process, the vehicle's overflow tank hose (not shown) should be disconnected and then used coolant hose 120 should be connected to the vehicle's radiator nipple (not shown). Next, the mode switch 140 should be placed in vacuum mode to evacuate more coolant. At this stage, the vehicle's pressure release lever (not shown) should be pulled to release any pressure and then the vehicle's radiator cap should be removed.
At this point, the used coolant hose 120 should be disconnected from the vehicle's radiator nipple and should be inserted into the vehicle's radiator fill neck (not shown). Next, the mode switch 140 should be placed in vacuum mode to evacuate coolant until coolant in the radiator preferably falls below the vehicle's upper radiator hose connection. As for the next step of the operation, the used coolant hose 120 should be removed from the vehicle's radiator and re-inserted into the vehicle's radiator overflow tank to evacuate the overflow tank completely using the vacuum mode of the service apparatus 100 .
At this stage, the vehicle's upper radiator hose should be disconnected from the vehicle's radiator inlet (not shown). Next, the new coolant hose 130 should be connected to the radiator inlet and the used coolant hose 120 should be connected to the vehicle's upper radiator hose. At this point, the mode switch 140 may be placed in fluid exchange mode to replace used coolant with new coolant from the reservoir tank 265 . This operation should continue until the coolant level has reaches a middle point in the vehicle's radiator filler neck (not shown). Next, the mode switch 140 should be placed in off mode and the vehicle's radiator cap reinstalled securely.
At this step, the vehicle's engine should be started and the mode switch 140 of the service apparatus 100 should be placed in fluid exchange mode. This operation should continue until the tank-level indicator 125 indicates that new coolant has fallen below a low level or until the coolant in the disposal hose 122 appears to be clean. If either condition occurs, the mode switch 140 should be placed in off position and the vehicle's engine should be turned off.
In a preferred embodiment, when the reservoir tank 265 falls below a predetermined low level, the low-fluid-level indicator 110 illuminates and the warning alarm 137 sounds to indicate that the fluid exchange operation has ended. At this stage, the service apparatus 100 automatically reverts to the bypass or off mode and the vehicle's coolant simply passes through the service apparatus 100 and return to the vehicle in a closed loop fashion. Once the mode switch 140 is placed in off mode, the warning alarm's 137 audible sound becomes disabled.
At this point, the disposal hose 122 should be removed from the disposal tank and inserted into the vehicle's coolant recovery tank (not shown). Next, the service apparatus 100 should be placed in vacuum mode via the mode switch 140 to fill the vehicle's coolant recovery tank. Once the vehicle's coolant recovery tank reaches an acceptable fluid level, the switch mode 140 should be placed in off position to end the vacuum operation.
For the next step of the service operation, the pressure gauge 135 should be checked to verify that service apparatus 100 indicates zero or about zero pressure. Next, the vehicle's radiator cap (not shown) should be removed in order to assure that the coolant level in the vehicle's radiator is below the upper radiator hose connection point. If the coolant level in the radiator is unacceptable, the disposal hose 122 should be inserted in a disposal tank—or preferably a clean tank—and the mode switch should be placed in vacuum mode to drain the excess clean coolant from the vehicle's radiator. Next, the service apparatus 100 should be disconnected from the vehicle and the vehicle's upper radiator hose should be connected to the radiator and overflow tank hose to radiator nipple.
At this stage, the new coolant hose 130 should be inserted into the vehicle's radiator filler neck and the top-off switch 145 should be turned on, i.e., placed in top-off mode, in order to fill or top-off the coolant in the radiator. Preferably, similar top-off procedure should be followed to fill or top-off the coolant in the radiator overflow tank, if deemed necessary. At this point, the service process is complete in accordance with one exemplary method of the present invention.
Turning to the flow system 200 , the aforementioned modes of operation of the service apparatus 100 are described below.
In one mode of operation, the service apparatus 100 is in off or by-pass mode when the mode switch 140 is placed in off position. The off mode is the default setting of the service apparatus 100 . In this mode, when the service apparatus 100 is connected to an operating vehicle, the service apparatus is in a flow through or by-pass mode. In other words, the coolant fluid flowing from the vehicle passes through the service apparatus 100 and return to the vehicle's system.
Referring to FIG. 2, the off or by-pass mode may be described as follows. A used coolant hose connector 205 , preferably a hydraulic connector, couples the used coolant hose 120 to the vehicle's radiator system. Similarly, a new coolant hose connector 235 , preferably a hydraulic connector, couples the new coolant hose 130 to the vehicle's radiator system. In the by-pass mode, a vacuum solenoid 215 , preferably a two-way solenoid, and a vacuum pump 220 are turned off such that no fluid may flow through the vacuum solenoid 215 or the vacuum pump 220 . An exchange solenoid 225 , preferably a three-way solenoid, on the other hand, is set such that the fluid passes through the exchange solenoid 225 down to a used-coolant check valve 230 . The used-coolant check valve 230 allows used fluid to flow through and towards the new coolant hose connector 235 .
As shown, a new coolant check valve 245 is strategically positioned to prevent flow of used coolant towards the new coolant reservoir tank 265 . A filter 210 is preferably placed in the fluid path to prevent unwanted particles from blocking the fluid paths, the solenoids 215 and 225 or the vacuum pump 220 . The pressure gauge 240 also provides the operator with the service apparatus 100 pressure based on which the operator may determine as to whether the flow has been restricted. Accordingly, in off or by-pass mode, used coolant enters the service apparatus 100 , passes through the used coolant hose connector 205 and through the used coolant hose 120 through a filter 210 , through the exchange solenoid 225 , through the used-coolant check valve 230 and then through the new coolant hose 130 and the new coolant hose connector 235 back to the vehicle's radiator system (not shown).
Conventional service machines, however, merely provide an open hose that causes the vehicle's fluid to flow out of the vehicle's radiator system when the vehicle's engine is running. As a result, the vehicle's radiator system loses its fluid and the vehicle's engine overheats. In this exemplary embodiment of the present invention, on the other hand, a closed loop is established in the off mode that causes the vehicle's radiator fluid to return back to the radiator system while the vehicle's engine is running. In other words, no fluid is taken out of the vehicle's radiator and no fluid is added, rather the used radiator fluid simply cycles through the service apparatus 100 and returns back into the vehicle's radiator system. The off mode of the present invention is even more advantageous in conjunction with the fluid exchange mode, as explained below, wherein the service apparatus automatically reverts to the off mode at the end of the fluid exchange mode and causes the fluid to circulate and not to be drawn out of the vehicle's radiator system at the end of the fluid exchange process. In conventional systems, however, the operator must manually control this time critical process.
In the vacuum mode of operation, the vacuum pump 220 and the vacuum solenoid 215 are activated to apply vacuum to the vehicle's radiator system. As a result, used coolant is pulled from the vehicle's system through the used coolant hose connector 205 and the used coolant hose 120 , through the filter 210 , the vacuum solenoid 215 and the vacuum pump 220 . The old coolant then flows to a waste check valve 270 to the disposal tank (not shown) or a clean tank, if clean fluid is being vacuumed.
The flow system 200 also includes a pressure pump relief valve 255 that can prevent an unwanted hydraulic pull that may be created due to human errors. An unwanted hydraulic pull may occur if the operator erroneously connects the new fluid hose 130 and the used fluid hose 120 to the vehicle's system in place of the other. In this case, an unwanted hydraulic pull is created between the new coolant hose connector 235 and the used coolant hose connector 205 and the vacuum pump 220 that may cause new fluid to be drawn from the new fluid reservoir tank 265 . The pressure pump relief valve 255 is positioned to prevent new fluid to be drawn from the reservoir 265 as a result of a hydraulic pull.
In conventional service machines, in order to prevent drainage of coolant into public drainage system, the operator must place a pan under the vehicle to retain spills. The performance of this step is required by the environmental law to prevent drainage of hazardous materials.
When the service apparatus 100 is placed in fluid exchange mode via the mode switch 140 , the service-in-progress indicator light 105 illuminates, and a pressure pump 260 and the exchange solenoid 225 are activated. In this mode, the old fluid enters the service apparatus 100 through the used coolant hose connector 205 and the used coolant hose 120 . The old fluid then flows through the filter 210 , bypassing the path including the vacuum solenoid 215 and the vacuum pump 220 , because they are both in off state, but flowing through the exchange solenoid 225 to reach the waste check valve 270 . The exchange solenoid's 225 path to the used-coolant check valve 230 is deactivated so that flow of used fluid towards the used-coolant check valve 230 is not allowed. Furthermore, the pressure pump 260 is activated to pump new fluid out of the new fluid reservoir tank 265 towards the pressure pump relief valve 255 , passed the new fluid check valve 245 towards the new fluid hose 130 and the new fluid hose connector 235 into the vehicle's radiator system. An excess pressure relief valve 250 is preferably positioned such that it is connected to the reservoir tank 265 at one end and between the pressure pump relief valve 255 and the new fluid check valve 245 at the other end. The purpose of the excess pressure relief valve 250 is to allow new fluid to revert back into the reservoir tank 265 partially or completely depending upon the rate at which the vehicle's system is accepting new fluid. The excess pressure relief valve 250 opens based on excess pressure, so that the vehicle's engine or the service apparatus 100 do not have to be stopped and restarted to adjust inflow or outflow of the fluid. Rather, the fluid flow is automatically controlled via the excess pressure relief valve 250 . In some conventional systems, an electrical switch is used to stop the pressure pump at a given pressure. Accordingly, in such machines, the flow of fluid cannot be partially controlled but path is either closed or open.
During the fluid exchange mode, the pressure gauge 240 provides the service apparatus 100 pressure to the operator, so the operator may determine the flow speed and whether the flow is restricted. During this operation, a used-coolant check valve 230 is positioned to prevent flow of fluid to the exchange solenoid 225 . The used-coolant check valve 230 , however, may not be used in some embodiments, since the exchange solenoid 225 may itself block flow of new fluid. Yet, the used-coolant valve 230 serves an advantageous purpose, for example in the vacuum mode, wherein the operator may erroneously utilize the new coolant hose 130 rather than the used coolant hose 120 to vacuum fluid.
The top-off mode of operation is activated when the top-off switch 145 is turned on. As described above, in one mode of operation the fluid exchange mode terminates when new fluid in the reservoir tank 265 reaches a predetermined low level. At this stage, the reservoir tank 265 preferably contains approximately three quarts of new fluid. The top-off mode of the service apparatus 100 overrides the low-level shut-down and allows more fluid, below the low-level in the reservoir tank 265 , to be withdrawn from the reservoir tank 265 in order to top-off the vehicle's radiator system. In conventional systems, the operator must either make a batch of new fluid by mixing water and coolant or save some new fluid in a separate container in order to manually top-off the cooling system and fill the radiator overflow tank at the end of the fluid exchange operation.
Activating the top-off switch 145 causes the low-fluid-level indicator light to go off. In this mode, the pressure pump 260 is activated causing new fluid to be pump out of the reservoir tank 265 towards the pressure pump relief valve 255 , passed through the new fluid check valve 245 to the new fluid hose 130 and the new fluid hose connector 235 into the vehicle's radiator system. During the top-off mode, some new fluid may revert back to the reservoir tank 265 via the excess pressure relief valve 250 . As explained above, the excess pressure relief valve 250 opens partially or completely depending upon the back pressure.
Turning to FIG. 3, an exemplary electrical system 300 of the present invention is illustrated. The electrical system 300 includes a circuit breaker element 305 in connection with the circuit breaker 136 . The circuit breaker element 305 provides protection to the electrical system 300 against unwanted voltage fluctuations. The electrical system 300 further includes four relays 315 , 370 , 375 and 380 that are set up according to the modes of operation of the service apparatus 100 . The electrical system 300 also includes electrical connections for a service light 320 and a low-level light 365 to provide illumination to the service-in-progress indicator light 105 and the low-level-fluid indicator light 110 , respectively. FIG. 3 further illustrates that the service light 320 is in communication with a diode 310 and a top-off switch 335 via the relay 315 . As a result in the fluid exchange mode, the relay 315 is activated such that the service light 320 provides voltage to illuminate the service-in-progress indicator light 105 and also to turn the pressure pump 340 on.
The electrical system 300 further comprises pump electrical connections 340 and 345 to provide electrical voltage to pressure pump 260 and the vacuum pump 220 , respectively. A low level switch 330 is also provided to terminate the exchange fluid mode and cause the service apparatus 100 to revert to off mode when the reservoir tank 265 reaches a predetermined low fluid level. As shown, the electrical system 300 also provides an alarm electrical connection 360 to activate or deactivate the warning alarm 137 . The alarm electrical connection is further connected to an alarm diode 355 that is coupled to the relay 370 . The electrical system 300 further comprises solenoid electrical connections 385 and 390 to control the operation of the vacuum solenoid 215 and the exchange solenoid 225 , respectively.
While particular embodiments, implementations, and implementation examples of the present invention have been described above, it should be understood that they have been presented by way of example only, and not as limitations. The breadth and scope of the present invention is defined by the following claims and their equivalents, and is not limited by the particular embodiments described herein. | Method and apparatus, for servicing engine cooling systems, including a service inlet, a vacuum pump, a two-way solenoid interposed between the vacuum pump and the service inlet, a service outlet, a disposal hose, a new fluid tank, a pressure pump interposed between the service outlet and the new fluid tank, a three-way solenoid interposed between the service outlet and the two-way solenoid, a low-level trigger mechanism, a flow control relief valve and other elements to enhance various modes of operation. The apparatus is capable of performing various operations, including closed-loop fluid cycle, fluid vacuum, fluid top-off, fluid exchange and fluid flow control. | 5 |
BACKGROUND OF THE INVENTION
The present invention provides unique methods and apparatus for identifying microscopic particles, such as protozoa and other microbes suspended in a fluid or gas.
Currently accepted methods for identification of pathogenic microscopic particles require relatively long, labor-intensive process. For instance, to determine whether Cryptosporidium parvum or Giardia lamblia is present in drinking water, suppliers must employ the USEPA method 1622, a long and labor-intensive procedure. Clinical laboratories and food inspectors also must use long labor-intensive procedures to locate and identify harmful bacteria.
Unfortunately, there are many circumstances when positive identification of a microbe cannot wait. A contamination of drinking water by Cryptosporidium must be recognized immediately, before the water is delivered to homes. Likewise, identification of a specific cause of a disease, such as bacterial meningitis, many times cannot wait the hours required. Finally, detection and identification of bacteria in food sources, such as beef, takes so long that in most cases, the food is distributed before the problem is discovered.
A variety of methods and apparatus exist for detection of microscopic organisms. For instance, De Leon, et al. in U.S. Pat. No. 5,770,368 teaches Cryptosporidium detection methods. The viability or infectivity of the encysted forms can be determined by synthesizing a cDNA from an induced HSP RNA template using a primer that is specific for particular genus or species of protozoa, followed by enzymatic amplification of cDNA. Alternatively, infectivity can be determined by amplifying HSP DNA from infected cells using a primer pair that is specific for a particular genus or species of protozoa.
Steele, et al. in U.S. Pat. No. 5,693,472 discloses detection of Cryptosporidium parvum. A method and kit for the detection of Cryptosporidium parvum in aquatic and biological samples such as surface water or feces is described. The method relies on the use of primers to detect all or a portion of at least one DNA sequence characteristic of Cryptosporidium parvum, the sequence being all or part of the genomic regions referred to as 38G and HemA contained within recombinant plasmids pINV38G, and pHem4, respectively.
Pleass, et al. in U.S. Pat. No. 5,229,849 discloses laser Doppler spectrometer for the statistical study of the behavior of microscopic organisms. An improved method and system of monitoring and identifying microbiota swimming in a fluid or moving across surfaces in a fluid provides a sensitive method for rapidly measuring very small changes in activity, and detecting and identifying individual microbes in relatively large volumes of fluid, even in the presence of detritus. The system comprises a laser station, a sample collector station, a picture taking station and a monitoring station.
Wyatt, et al. in U.S. Pat. No. 4,548,500 teaches process and apparatus for identifying or characterizing small particles. An apparatus and process are described for the characterization and/or identification of individual microparticles based upon the measurement of certain optical observables produced as each particle passes through a beam of light, or other electromagnetic radiation. A fine beam of, preferably, monochromatic, linearly polarized light passes through a spherical array of detectors, or fiber optics means, to transmit incident light to a set of detector means, and a stream of particles intersects the beam at the center of the spherical array. Selected observables calculated from the detected scattered radiation are then used to recall specific maps, from a computer memory means, one for each observable.
Lee, et al. in U.S. Pat. No. 5,473,428 disclose an interferometric temperature sensing system having a coupled laser diode wherein the magnitude is adjusted corresponding to a prior feedback laser beam. An interferometric temperature sensing system provides a simplified design for accurately processing an interference fringe pattern using self coupling effects of a laser detection element, where a laser diode and an optical detection element are combined in one package.
Curtis Thompson's U.S. Pat. No. 5,582,985 teaches detection of mycobacteria. The invention provides a method, compositions, and kits useful for detecting mycobacteria in a sample. The method includes contacting the sample with a formaldehyde solution, an organic solvent, and a protein-degrading agent prior to hybridizing a mycobacteria-specific nucleic acid probe to the sample. The invention has particular utility in detection and susceptibility screening of human-disease causing mycobacteria such as mycobacterium tuberculosis.
SUMMARY OF THE INVENTION
The unique system of the present invention provides accurate and valid measurements for identifying a wide variety of microscopic particles, such as protozoa and other microbes suspended in a fluid or gas. The inventive methodology provides a procedure for the quantitative and qualitative identification of particle species derived from measurement of light scattered by the particle that is collected by an array of optical sensors surrounding the suspended particle, in a convenient and reliable manner.
In more detail, the light scattered by the suspended particle is detected by the sensor array and converted to an electrical signal, e.g. a voltage. The voltage from each sensor is entered into a modifying means component where the voltages are digitized and the resulting values are used as fingerprints for particle identification. The unique modifying component comprises prediction formulas derived from one or more sets of empirically determined one-dimensional or multi-dimensional probability histograms that are functions of one or more mathematical combinations of the digitized voltages. Each set consists of individual probability histograms, which give the likelihood that observed values of specific combinations of digitized voltages were produced by a specific particle species. Thus, the unique modifying component of the inventive system interprets the measured signals as “species specific” when the prediction formulas result in probability values that are large for a specific species.
In one embodied form, the inventive method for rapidly detecting and identifying microscopic particles for quantitative and qualitative measurement comprises the steps of:
a) suspending the particle to be identified in a control fluid contained within a sample chamber;
b) holding the sample chamber in a prescribed orientation with respect to an intense light source;
c) illuminating the sample chamber with said light source;
d) collecting and measuring the scattered light from the sample chamber by means of an array of optical sensors surrounding the sample chamber;
e) converting a voltage output from the array of sensors to a digital signal as the particle passes through the intense light source; and
f) comparing the derived signal with a library of probability histograms and statistically classifying the resultant data to identify the microscopic particles present.
In accordance with the present invention, the library consists of histograms for each particle species encompassed by a statistical classification algorithm that calculates the probabilities that the associated signal was produced by those particle species. The probability histogram is derived empirically from a measure of the frequency that a species of microparticle is associated with a specific range of values of a mathematical combination of the digitized sensor voltages. Thus, the frequency-of-occurrence histogram can be produced for one mathematical combination, i.e., a one-dimensional analysis or alternatively, can be produced for multiple mathematical combinations simultaneously, i.e., a multi-dimensional analysis.
In a presently preferred embodied form, the inventive apparatus comprises, in combination:
a) a polarized laser that produces a beam waist;
b) an optical chassis including multiple light detectors, each light detector positioned around and oriented to view, without obscuration, a common region of regard of the laser beam waist;
c) a sample chamber for containing a fluid sample to be analyzed;
d) means for holding the sample chamber in a prescribed orientation with respect to the laser beam waist and in the common region of regard of the light detectors;
e) means for causing the particles in the sample to circulate through the laser beam waist;
f) means for covering the light source and optical chassis to create a dark enclosure;
g) means for converting the light intensity values measured by the detectors into digital values:
h) means for continuously entering the digital values into a computer;
i) means for determining when a particle has entered the light beam at the common region of regard based on the digitized measurements;
j) means for converting the digitized values to calibrated values;
k) means for extracting Event Descriptors from the digitized and calibrated event data;
l) means for calculating Discriminant Function values from the Event Descriptors;
m) means for defining probability histograms that enable the calculation of the probability that a Discriminant Function value calculated from measured values was caused by a specific particle species;
n) means for identifying the most effective Discriminant Functions.
o) means for storing the probability histograms and Discriminant Functions in an Identification Library, one histogram for each particle species that can be identified and each Discriminant Function;
p) means for retrieving previously stored probability histograms and Discriminant Functions, one probability histogram for each particle species that can be identified with the Identification Library and each Discriminant Function;
q) means for calculating the probability for each particle species in the library for a given value of a Discriminant Function;
r) means for combining probabilities for each particle species that can be identified with the Identification Library; and
s) means for identifying the unknown particle based on a threshold.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a flow chart showing the steps to create an Identification Library and to identify particles using the Identification Library using the preferred embodied form of this invention;
FIG. 2 is a schematic of the complete identification system;
FIG. 3 is a close up of the beam waist of the laser. If the laser has a Gaussian intensity profile, spherical particles passing through the laser beam will scatter light that has a Gaussian shape versus time; and
FIG. 4 shows three normalized frequency-of-occurrence histograms. These plots show results for measured data of three particle species: a sample of 1.588±0.025-micrometer diameter polystyrene spheres (standard deviation of 0.016 micrometer), Giardia lamblia and Cryptosporidium parvum.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention provides a unique method and apparatus for a microscopic particle identification method based on a statistical analysis of measured data. The method depends on three interrelated parts (see FIG. 1 ): The measurement instrument and raw data processing system; the creation of an Identification Library; and the use of the Identification Library.
This invention provides the means to rapidly detect and identify microbes and other types of particles. The system is based on a measure and analysis of light scattered off particles as they pass through an intense collimated light source. When particles are comparable to and somewhat larger than the wavelength of the incident light, light predominantly diffracts off the particle, scattering light energy in all directions. The light intensity in the various directions depends explicitly on the size and shape of the particle and wavelength of the incident light. In principle, one may calculate a particle size and shape from a high angular resolution measure of the light intensity and electromagnetic phase of all the scattered radiation. This, in fact, is a common practice in aerospace when dealing with radar signatures of vehicles. However, this technique is impractical when dealing with visible light. Additionally, measuring the exact size and shape of particles, such as bacteria, is not useful for identification due to natural size and shape variations. In accordance with the present invention, a system for particle identification by measuring only a small part of the scattered light is provided. By comparing the measured result with a library of previously made measurements, performed on a variety of types of particles, accurate particle identification is achieved.
The following definitions will be helpful to create a more complete description of the preferred embodiments.
The term “fluid” shall mean a liquid or gas media.
The term “light” shall mean electromagnetic radiation.
The term “common region of regard” shall mean a small region in space that is viewed simultaneously by all light detectors.
The term “without obscuration” shall mean no visual blocking, warping or vignetting.
The term “transparent” shall mean optically clear at the wavelength of employed light.
The term “sample chamber” shall mean a transparent enclosure that contains the sample.
The term “detectors” shall mean an electronic device that is sensitive to light and converts the incident light into a voltage or current with magnitude proportional to the incident light intensity.
The term “optical chassis” shall mean the framework, optical detectors and electronics that surround the sample chamber.
The term “apply calibration” shall mean to make corrections to the raw measured data such that measurements of standards will result in correct values.
The term “particle species” shall mean an individual class of particle such as a species of a microorganism or pollen or the type of article such as red blood cell, etc.
The term “event” shall mean a set of measured scattered light data taken as one particle passes through the light beam.
The term “frequency-of-occurrence histogram” shall mean a measure of how often the measurement of a particle species results in a specific value range for a given calculation of a mathematical combination of specific measurements.
The term “probability histogram” shall mean a normalized frequency-of-occurrence histogram such that the area under the curve (one-dimensional case) or the volume under the curve (multi-dimensional case) is one.
In one embodied form, the inventive method for rapidly detecting and identifying microscopic particles for quantitative and qualitative measurement (the third of three interrelated parts) uses the measurement instrument shown in FIG. 2 and comprises the steps of:
a) suspending the particle to be identified in a ultra-high quality water contained within a glass vial;
b) holding the sample vial in an intense laser source such that the beam waist passes through the center;
c) collecting and measuring the scattered light from the glass vial by means of an array of optical sensors surrounding the sample chamber;
d) converting a voltage output from the array of sensors to a digital signal as the particle passes through the intense light source; and
e) comparing the derived signal to at least one set of probability histograms to identify the microscopic particles present.
Accordingly, the identification of a particle species proceeds by initially measuring a statistically significant number of that species and deducing pertinent information from the measurements. After the collecting and archiving the relevant information in an Identification Library, identification of unknown particles proceeds by comparison of new measurements with the archived library of particle characteristics.
The system utilizes light scattered off particles that pass through the intense light source. FIG. 2 shows a schematic of one embodied form of an instrument to measure the scattered light and perform library creation and particle identification. An Optical Chassis provides the framework to support the optical detectors and constrain their field-of-view to a single common region of regard. The optical detectors collect and measure the intensity of the light scattered outside a sample chamber. An Event Processor subsystem continuously digitizes the voltage generated by the detectors and monitors the digitized voltage to dynamically extract a background signal and to determine when a particle passes through the laser beam.
When the Event Processor detects a particle passing through the laser beam, the processor keeps the digitized voltage from each detector until the particle passes completely through the beam. After the particle passes through the beam, the Event Processor applies calibration, then extracts from the digitized data, specific data (Event Descriptors) required by the particle identification algorithm and passes the Descriptors to the ID processor subsystem.
The ID Processor subsystem uses the Event Descriptors to form Discriminant Function values to cross-reference into the particle species Identification Library. The library contains numerous sets of probability histograms that can be used to calculate the probability that observed Discriminant Function values resulted from specific particle species. The ID Processor uses the probability histograms and a statistical classification algorithm to deduce the identity of the particle that passed through the laser beam. The ID Processor presents the identity of the particle on the display.
Thus, the first inventive process stage creates the Identification Library utilizing a large number of measurements by the measurement instrument. The second inventive process stage uses the measurement instrument and library to identify unknown particles.
Understanding the Library creation process relies on understanding data measured for a spherical particle. When a spherical particle passes through the collimated beam, the photodetectors measure a time dependent intensity dependent on both the particle speed and the cross-sectional intensity profile of the laser. FIG. 3 shows that when the laser has a Gaussian cross-sectional intensity profile, a spherical particle will also have a Gaussian scattered light intensity versus time (note: the particle is much smaller than the diameter of the beam). Thus, v(d,t), the voltage measured on detector, d, as a function of time, t, is also Gaussian. The same particle passing through the beam waist along different paths will show Gaussian profiles with different magnitudes. Dividing the measured values, at each instant in time, by a sum of one or more of the detector values at the same instant in time removes this path dependency. Thus:
v ′( d,t )= v ( d,t )/Σ d′ v ( d′,t ). Equation (1)
Here, d′ is some or all of the detectors. When the particles are spherical, the normalized values, v′(d,t), are constant as long as the signal strength is large enough. Additionally, the value is independent of the path taken by the particle as it passes through the laser beam.
The value of the ratio for spherical particles from equation (1) is predictable when the wavelength, particle diameter and the index-of-refraction of the particle and the fluid are known. Thus, for spherical particles, it is sufficient to use a single ratioed value from each detector to characterize the particle that passed through the beam. These single ratioed values from each detector are called Event Descriptors since they uniquely describe the source of the event, that is, the particle that caused the event. In the following, ED(d) shall represent the Event Descriptor for detector d, that is, ED(d)=v′(d,t l ) where t l is a specific instant in time. Every spherical particle with the same size will produce the same Event Descriptors, ED(d). Thus, given a measurement of a spherical particle event, the diameter of the particle can be derived, in principle, from the values of the event descriptors.
When the particle is not a sphere, the Event Descriptors of equation (1) are no longer constant. A plot of v′(d,t) versus time will not result in straight lines. The shape of the curve depends on the orientation of the particle as it passes through the beam. The same particle passing through the laser beam repeatedly will produce a variety of plot shapes. Likewise, different particles of the same particle species will also produce a variety of plot shapes. As a result, the Event Descriptors as described above depend on time. Consequently, to account for non-spherical particles, the concept of the Event Descriptor is relaxed to denote data that simply is characteristic of the event even though the descriptor value may not be constant in time for the particle species.
The identification method requires a specific scheme to extract Event Descriptors from the event data. There are a variety of schemes. Two are:
1. Select an Event Descriptor value that is the maximum value of ED(d,t)=v′(d,t) attained during the event. That is: ED d =max (v(d,t)/Σ d′ v(d′,t)).
2. Select an Event Descriptor value that is the value of ED(d,t n ,)=v′(d,t n ) at the time, t n , when the value v′(d n ,t) is a maximum for a specific detector, d n , during the event. That is: ED d =v(d,t′ n )/Σ d′ v(d′,t′ n ) where t′ n is the time when detector d=n is a maximum.
Since the event data measured when a non-spherical particle passes through the laser beam depends on its orientation, one cannot directly identify the particle given the Event Descriptor values. However, one can use a statistical analysis to predict what the particle was. Measuring many particles of the same species will produce a family of Event Descriptor values. The family of values describes the range of values that the Event Descriptors take. It is important to note that the range of values is limited in extent. Plotting these measured values as a frequency-of-occurrence histogram versus Event Descriptor value results in a graph similar to that in FIG. 4 . As this graph indicates, the range of values for Event Descriptors are limited and, more importantly, some values are more likely than others are.
A frequency-of-occurrence histogram plot for a different particle species will result in a somewhat different histogram graph since the particles will have different size, shape or optical characteristics. FIG. 4 shows normalized histogram plots for three different particle species: Giardia lamblia, Cryptosporidium parvum and a sample of 1.588 micrometer diameter polystyrene spheres for an Event Descriptor, ED 1 . Given a specific measured value for ED 1 , such as the point α on the graph, one can deduce that the particle is likely to be a Giardia lamblia or Cryptosporidium. Likewise, if the value is β, then the particle is likely to be a 1.588-micrometer diameter sphere. However, the identification is not absolute. At both point's α and β, there is still a non-zero chance that the event was caused by any one of three particle species.
Clearly, the process requires additional information to increase the likelihood of an accurate identification. The additional information comes from using another set of histograms for a different Event Descriptor, ED 2 and so on. The identification process becomes a matter of deducing a particle species from the probability that measured Event Descriptor values were produced by the different particles in the data set of pre-measured histogram curves. The data set of pre-measured normalized histograms is called an Identification Library.
The Library Creation stage starts with the Event Descriptors extracted from the event data and processed by the measurement instrument. The Event Descriptors are reorganized into a large set of Discriminant Functions. Probability histograms for each function and each different particle species to be included in the library are calculated. The strength of each Discriminant Function in providing species-to-species distinction is calculated. The best Discriminant Functions are identified and pertinent data saved for use by the identification procedure.
Discriminant Functions enhance the distinction between particle species. Consider data for two different spherical diameters. One finds cases where the value ED 1 is large for one sphere and small for the other sphere while ED 2 is small for the first sphere and large for the second. In this case, the ratio ED 1 /ED 2 is a good discriminator between the two different spheres. This ratio is large for one sphere diameter and small for the other. In this case, a histogram for the values resulting from the Discriminant Function DF=ED 1 /ED 2 will show greater separation between the curves for the two different particle species than the histograms of the individual Event Descriptors.
Discriminant Functions are simply generalizations of the Event Descriptor concept. For example, the following three relations between Event Descriptors are each Discriminant Functions: DF 1 =ED 1 , DF 2 =1/ED 2 and DF 3 =ED 1 /ED 2 . Since the Discriminant Functions include the individual Event Descriptors, the following discussion will only use Discriminant Function.
The histograms are easier to use when normalized. That is, the area under the curve is one (one-dimensional case) or the volume under the curve is one (multi-dimensional case). The resulting curves then are like probability densities. These probability histograms now give directly the probability that a specific Discriminant Function value resulted from a measurement of a specific particle species.
As described above, one probability histogram for each particle species cannot classify a measured Event as a specific particle species. Consequently, a set of densities derived from a set of Discriminant Functions is required. Unfortunately, there may exist Discriminant Functions that do not exhibit good separation between the probability histogram curves for different particle species as demonstrated in FIG. 4 . While the separation between Giardia and the spheres and between Cryptosporidium and the spheres is good, the separation between Giardia and Cryptosporidium is not very good. Consequently, the Discriminant Function plotted in FIG. 4 does not provide useful identification information distinction between Giardia and Cryptosporidium. The choice of which set of Discriminant Functions to use for identification is crucial: Discriminant Functions cannot be chosen haphazardly. as Additionally, there is no a priori reason to select one set of Discriminant Functions over another. Fortunately, given the high speed and large data handling capabilities of modern computers, one can simply calculate the densities for a large set of functions, sort through the results and identify those that provide good separation between the probability histogram curves for individual particle species.
With the best performing set of Discriminant Functions identified, the Identification Library may be created and archived. The Library must contain a list of the species encompassed by the probability histograms. Each set of probability histograms must have its associated Discriminant Function.
To identify unknown particles with the Identification Library, load the library into the identification computer memory. The measurement instrument and raw data analysis procedure measures the unknown particle and extracts Event Descriptor data as described.
The identification procedure begins by measuring and collecting the data for an unknown particle as it passes through the laser beam. The Event Processor digitizes the resulting signals and extracts the Event Descriptor data from the event. The Event Processor then passes the Event Descriptor data to the ID Processor that attempts to identify the particle.
The ID Processor begins by calculating values for the Discriminant Functions from the Event Descriptors for the first set of probability histograms in the library. Looking up or interpolating the probability values from the probability histogram for each respective particle species and applying a statistical classification algorithm determines the probability that a specific particle species generated these Discriminant Function values. The result is an array of probabilities associated with these first Discriminant Functions: p(df, species), where df in this case is the Discriminant Function set number, 1 in this case—that is, it is the first set of Discriminant Functions. The ID Processor repeats this process for all sets of Discriminant Functions and their associated probability histograms in the library.
One possible statistical classification algorithm uses the set of probability values described as p(df, species), where df is the specific Discriminant Function and species is the particle species, in the following way. The probabilities for each different particle species (species) are combined to form a single probability value for that species:
p (species)=Σ df W ( df )× p ( df ,species),
where W(df) is a weighting for the probability histogram resulting from the Discriminant Function set, df.
Particle species identification occurs by proper interpretation of these final probability values. One embodied interpretation is to use thresholds. If p(species)>t(species), where t(species) is the threshold value for a specific particle species, and all other values are less than their thresholds, then the particle is identified as that species. If more than one probability is above its respective threshold or if no probabilities are above threshold then the particle cannot be identified.
In a presently preferred embodied form, the inventive apparatus comprises, in combination:
a) a polarized laser that produces a beam waist;
b) an optical chassis including multiple light detectors, each light detector positioned around and oriented to view, without obscuration, a common region of regard of the laser beam waist;
c) a sample chamber for containing a fluid sample to be analyzed;
d) means for holding the sample chamber in a prescribed orientation with respect to the laser beam waist and in the common region of regard of the light detectors;
e) means for causing the particles in the sample to circulate through the laser beam waist;
f) means for covering the light source and optical chassis to create a dark enclosure;
g) means for converting the light intensity values measured by the detectors into digital values;
h) means for continuously entering the digital values into a computer;
i) means for determining when a particle has entered the light beam at the common region of regard based on the digitized measurements;
j) means for converting the digitized values to calibrated values;
k) means for extracting Event Descriptors from the digitized and calibrated event data;
l) means for calculating Discriminant Function values from the Event Descriptors;
m) means for defining probability histograms that enable the calculation of the probability that a Discriminant Function value calculated from measured values was caused by a specific particle species;
n) means for identifying the most effective Discriminant Functions.
o) means for storing the probability histograms and Discriminant Functions in an Identification Library, one histogram for each particle species that can be identified and each Discriminant Function;
p) means for retrieving previously stored probability histograms and Discriminant Functions, one probability histogram for each particle species that can be identified with the Identification Library and each Discriminant Function;
q) means for calculating the probability for each particle species in the library for a given value of a Discriminant Function;
r) means for combining probabilities for each particle species that can be identified with the Identification Library; and
s) means for identifying the unknown particle based on a threshold. | Unique methods and apparatus are provided for rapidly identifying microscopic particles, such as protozoa and other microbes suspended in a fluid or gas. In one embodied form, the method comprises illuminating the particles to be detected with an intense light source such as a laser, detecting scattered light by means of an array of optical sensors surrounding a detection zone, converting the detected light to an electrical signal, and comparing the derived signal with at least one frequency-of-occurrence/probability histogram curve to qualitatively and/or quantitatively identify the microscopic particles present. | 6 |
This is a continuation of application Ser. No. 07/653,083, filed Feb. 8,1991, now abandoned.
TECHNICAL FIELD
This invention relates generally to the field of prosthetic hernioplasty, the surgical repair of inguinal hernias using a prosthesis. In particular, it relates to a method for laparoscopic prosthetic hernioplasty, that is, the laparoscopic surgical repair of direct space inguinal hernias and right and left indirect space inguinal hernias and to a unique prosthesis used during those repairs.
BACKGROUND ART
A hernia is an abnormal protrusion of an organ, tissue, or any anatomical structure through a forced opening in some part of the surrounding muscle wall. For example, if a part of the intestine were to protrude through the surrounding abdominal wall, it would create a hernia--an abdominal hernia.
Hernias occur in both males and females in the groin area, also called the inguinal region. In both sexes, the abdominal wall may be weak on both right and left sides a little above the crease in the groin. Hernias are found most frequently in males where the potential for weakness originates during the development of the fetus when the testicles are located inside the abdomen. Just prior to birth, the testicles "descend" and leave the abdomen and enter the scrotum, the sac that contains the testicles. In doing so, they push their way through the lower portion of the abdominal wall. Although the abdominal wall "closes" around the spermatic cord to which the testicle is attached after the testicles descend, the area remains slightly weakened throughout adult life. If a part of the intestines or other tissue within the abdominal cavity pushes through one of the weak spots, it forms a hernia--an inguinal hernia.
Before the piece of intestine or other abdominal cavity tissue, called the hernial mass, makes its way through the weak spot in the muscle, it must first push its way through the peritoneum, the membrane that lines the abdomen. The hernial mass does not tear the peritoneum, however. Thus, when the intestine protrudes, it merely takes the peritoneum with it and is covered by it. The peritoneal covering surrounding the piece of protruding intestine is called a hernial sac.
Inguinal hernias can be indirect space inguinal hernias or direct space inguinal hernias. An indirect space inguinal hernia occurs in the following manner. The lower part of the abdominal wall where such hernias occur, the inguinal region, is comprised of two layers, an inner layer and an outer layer. Each layer has a weak spot in it but the weak spots are not directly aligned with each other. The weak spots in each layer are positioned slightly apart from each other.
The weak spot in the inner layer is called the internal inguinal ring. In starting to form the hernia, the hernial mass begins protruding through this internal abdominal ring adjacent to the spermatic cord. To reach the weak spot in the outer layer, called the external inguinal ring, the hernial mass must move for a short distance toward the midline of the body between the internal layer and the outer layer of the abdominal wall. This passageway is called the inguinal canal. The hernia that is formed by a hernial mass that passes through the internal inguinal ring, the inguinal canal, and out through the external inguinal ring, is called an indirect space inguinal hernia.
There are two types of indirect space inguinal hernias, right and left. A hernia that is formed on the right side of the body just above the crease in the groin area is called a right indirect space inguinal hernia. In this case, the external inguinal ring is positioned medially approximately 30°-60° to the left of the internal inguinal ring. On the other hand, a hernia that is formed on the left side of the body just above the crease in the groin area is called a left indirect space inguinal hernia. In a left indirect space inguinal hernia, the external inguinal ring is positioned medially approximately 30°-60° to the right of the internal inguinal ring.
The second type of hernia is formed when the hernial mass stretches out or pushes through weakened muscle wall located proximal to the internal inguinal ring. This type of hernia is called a direct space inguinal hernia. Direct space inguinal hernias may form one or more years after a patient has had a repair of an indirect space inguinal hernia unless both areas are supported at the same time.
Traditional surgical repairs of both direct and indirect inguinal hernias have used the conventional external approach called reparative herniorrhaphy. Reparative herniorrhaphy requires laparotomy, an incision two to four inches in length made in the abdominal wall. The external approach uses a prosthetic patch that covers the outermost surface of the defect without lending any major immediate support to the defect itself or the surrounding muscle wall. Scarification of the covering and defect sufficient to allow resumption of unrestricted activities, occurs only after five to six weeks resulting in a lengthy postoperative recovery period with significant patient discomfort that requires considerable pain medication. In addition, when the external method fails to use a prosthetic device and relies solely on the patient's natural tissue for outlying support to the surrounding area, recurrence of direct space inguinal hernias is relatively high (5%). Further complications resulting from reparative herniorrahapy include infection and either a complete or partial wasting away (atrophy) of the testicles due to obstruction of the testicular blood supply.
In accordance with the method of the present invention, inguinal hernias are repaired using laparoscopic surgery. Laparoscopic surgery is less invasive, less traumatic surgery that involves visualizing the interior of the abdominal cavity using an illuminating optical instrument, a laparoscope, that is placed through a puncture orifice in the abdominal wall. Laparoscopic procedures have value as a diagnostic and operative tool for general surgery, as well as for gynecological surgery wherein such procedures are widely used. The effective use of laparoscopic procedures in the repair of inguinal hernias and the like has heretofore not been possible.
The instrument inserted into the body in a laparoscopic procedure is called a "trocar" and comprises a cannula or trocar sleeve (a hollow sheath or sleeve with a central lumen) into which fits an obturator, a solid metal rod with an extremely sharp three-cornered tip used for puncturing the muscle. The obturator is withdrawn after the instrument has been pushed into the abdominal cavity. The trocar sleeve remains in the body wall throughout the surgical procedure and various instruments used during laparoscopic procedures are introduced into the abdomen through this sleeve. Trocars are available in different sizes to accommodate various instruments.
The trocar sleeves used in laparoscopic procedures are pertinent to the present invention because they provide the pathway for insertion of the prosthetic device of the present invention into the abdomen. Representative diameters are 3, 5,10 and 11 millimeters with the 5,10 and 11 millimeters being employed most frequently in accordance with the present invention. While the use of a trocar in laparoscopic surgery is beneficial in that it results in only a small puncture wound in the patient's abdomen, the small diameter of the trocar also limits the size of surgical instruments and prosthetic devices which may be inserted in the trocar. The adaptation of laparoscopic procedures to the repair of inguinal hernias, therefore, requires the development of special surgical equipment and procedures.
The advantages of laparoscopic surgery include: simplifying the general surgery procedure so that it can be done on an outpatient basis; providing the surgeon the opportunity for viewing intra-abdominal viscera without laparotomy, a large incision made in the abdominal wall; using small puncture wounds as opposed to large incisions, lessening the trauma to anterior abdominal wall musculature; providing the surgeon with the ability to diagnose indirect inguinal hernias and direct inguinal hernias before signs and symptoms become advanced; determining incision sites for laparotomies when such incisions are appropriate; reducing both patient and insurer medical costs by shortening hospital stays; and reducing postoperative patient discomfort with recovery times measured in days as opposed to weeks.
Heretofore, indirect space inguinal hernias have been repaired by the traditional method including laparotomy of the abdominal wall and the external covering of the defect. Laparotomy is an extremely invasive procedure, requiring five to seven weeks for post-operative recovery. Moreover, preventative steps with respect to direct space inguinal hernias have not always been conventionally attempted during the repair of indirect space inguinal hernias resulting in a significant incidence of direct space inguinal hernias years after the initial occurrence. While the laparoscopic repair of inguinal hernias has been attempted using the transperitoneal approach with and without the use of prosthetic mesh, recurrence of direct space hernias remains a problem because the hernial defect has been closed with staples with no mesh used for support or a mesh patch has been used to fill the internal opening of the hernial defect without giving support to the direct space adjacent to the indirect defect.
SUMMARY OF THE INVENTION
The problems outlined above that have inhibited the effective repair of direct space and indirect space inguinal hernias are in large measure solved by the method of inguinal hernia repair and prosthetic device in accordance with the present invention. The method of repair in accordance with the present invention enables the use of laparoscopic surgical techniques in repairing inguinal hernias, with the benefits associated therewith, while greatly reducing the recurrence of hernial defects.
The prosthetic device in accordance with the present invention is generally a unitary piece having an abdominal wall engaging base, a hollow projection, and a slurry retaining flap. The base includes a flange and a ledge. The ledge anchors the prosthetic device against the abdominal wall while the flange covers and gives support to the surrounding area where direct space inguinal hernia recurrence is high. The projection, situated between the ledge and the flange, is received within the defect associated with inguinal hernias and lends support thereto.
The prosthetic device in accordance with the present invention is inserted into the abdominal cavity by means of an insertion enabling device. The insertion enabling device includes a hollow tube and an obturator. The prosthetic device is received within the hollow tube. The obturator is positioned within the projection of the prosthetic device for use in expelling the device from the hollow tube and for positioning the device in relation to the defect.
The inguinal hernia defect is sized by a sizing device that includes a syringe, a connector, a guiding catheter and a balloon tip. The syringe is filled with air or liquid which is injected into the balloon tip placed in the hernia defect. Measuring rings painted on the balloon tip allow the surgeon to extrapolate the size of the defect as the filled balloon tip expands and to select the appropriately sized prosthetic device.
Repair of an inguinal hernia in accordance with the present invention includes the steps of identifying the hernia as a direct space or an indirect space inguinal hernia; sizing the hernia defect; inserting an appropriately sized prosthetic device into the abdominal cavity; placing the prosthetic device through the internal inguinal ring; positioning the prosthetic device against the inguinal wall; and filling the projection of the prosthetic device with a slurry mixture.
One of the advantages of the present invention is that immediate support is given to the hernial defect by the projection of the prosthetic device. Moreover, direct space hernia recurrences are mitigated due to the support given to the inguinal wall by the prosthetic device. Most significantly, the present invention allows for the effective use of laparoscopic surgery in the repair of direct space and indirect space inguinal hernias, making hernial repairs safer, less painful with less morbidity for the patient and more efficient for the surgeon.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary pictorial view of the interior of the abdomen of a patient with viscera removed;
FIG. 2 is a fragmentary detail view illustrating the appearance of a typical indirect inguinal hernia defect with intrusive viscera removed;
FIG. 3 is a perspective view of the preferred embodiment of the prosthetic device in accordance with the present invention;
FIG. 4 is a fragmentary perspective detail view showing a hollow obturator used to inject slurry material into the hollow projection of a prosthetic device in accordance with the present invention;
FIG. 5 is a perspective view of a measuring instrument used to measure the size of the anatomical defect being repaired in accordance with the present invention;
FIG. 6 is a fragmentary pictorial view showing the prosthetic device in accordance with the present invention being inserted into a trocar sleeve;
FIG. 7 is a pictorial view similar to that of FIG. 6 showing the prosthesis being introduced into the defect;
FIG. 8 is a view similar to that of FIG. 3 but with an obturator extending into the projection of the prosthetic device;
FIGS. 9-12 are perspective views of prosthetic devices in accordance with the present invention with the projection depicted in various lengths and widths and extending downwardly at various angles;
FIG. 13 is a perspective view of an alternative embodiment of a prosthetic device in accordance with the present invention especially designed for repair of a double inguinal hernia;
FIG. 14 is a sectional diagram showing the prosthetic device in accordance with the present invention inserted into an anatomical defect with the projection of the prosthesis substantially filled with a slurry material;
FIG. 15 is an enlarged fragmentary perspective view similar to that of FIG. 4.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 depicts the right quadrant of the lower portion of the abdominal region 10 of a patient. The lower portion of the abdominal region 10 is the region where indirect space and direct space inguinal hernias occur. The intra-abdominal cavity 12 of the patient is depicted in FIG. 1 and in enlarged detail in FIGS. 6 and 7. Puncture orifices 14, 16 are made in the abdominal wall 18 of the patient by the insertion of a trocar 19 through the abdominal wall 18 and into the intra-abdominal cavity 12. The abdominal wall 18 is comprised of three layers of muscle, the innermost transverse abdominal muscle 20, the internal oblique muscle 22 and the outermost external oblique muscle 24. The transverse abdominal muscle 20 is lined with the transversalis fascia 26, a sheet of fibrous tissue that separates the three layered abdominal wall 18 from the peritoneum 27. The peritoneum 27 abuts the transversalis fascia 26 and covers most of the viscera (not shown) located in the abdominal cavity 12.
The weak spot associated with indirect inguinal hernias is located at the internal inguinal ring 28 and the inguinal canal is indicated in FIG. 1 in phantom at 30. The weak spot associated with direct space inguinal hernia 32 is located in close proximity to the femoral ring 34. Vein 36 and iliac artery 38 extend through femoral ring 34. Spermatic cord 40 extends from the testicles (not shown) through the inguinal canal 30 to the internal inguinal ring 28. Forceps 42 are depicted in FIG. 1 as grasping rectus abdominal fascia 44 to expose muscle bundle 46 and anterior rectus sheath 48.
Indirect inguinal hernias are named by their clinical presentation. That is, an inguinal hernia occurring just above the crease in the groin area on the left side is called a left indirect inguinal hernia and an inguinal hernia occurring just above the crease in the groin area on the right side is called a right indirect inguinal hernia. As the hernial mass (not shown) moves through the inguinal canal 30, it passes through the peritoneum 27 that covers and surrounds it. The hernial mass that protrudes through the external inguinal ring is thus surrounded by the peritoneum 27 thereby creating a hernial sac (not shown).
Referring to FIGS. 3 and 8, the prosthetic device 50 for repairing direct space 32 and indirect space 28 inguinal hernias in accordance with the present invention comprises a unitary piece that broadly includes abdominal wall engaging base 52, hollow projection 54 extending outwardly from the abdominal wall engaging base 52, and slurry retaining flap 56.
Abdominal wall engaging base 52 includes upper surface 58, bottom surface 60, opposed base side margins 61, 62, flange 64, and ledge 66. The base 50 is formed of an appropriate thickness and extends from the upper surface 58 to the bottom surface 60. Ledge 66 is an appropriate length and extends from first base side margin 61 to lip edge 78 of projection 54, and anchors prosthetic device 50 against the fascia 44. Flange 64 is longer in length than ledge 66 and extends from lip edge 79 of projection 54 to the side margin 62 of base 52. Flange 64 is designed to cover the weak spot associated with direct space hernias 32.
Hollow projection 54 is positioned between flange 64 and ledge 66. Projection 54 is generally spheroconically shaped and includes a slurry receiving cavity 68, internal sidewall 70 and external sidewall 72, an uppermost portion 74 and lowermost foot 76. The internal sidewall 70 of projection 54 is continuous with the upper surface 58 of base 52. Internal sidewall 70 defines the slurry receiving cavity 68. The external sidewall 72 of projection 54 is integrally formed with the bottom surface 60 of base 52. Projection 54 extends downwardly at a generally acute angle from base 52. The diameter of the projection 54 is largest at the mouth 73 of the uppermost portion 74. Opposed lip edges 78, 79 are formed with the bottom surface 60 of base 52. Projection 54 tapers gradually from the mouth 73 to the lowermost foot 76.
Slurry retaining flap 56 includes inner face 80, outer face 82, opposed side portions 84, 86 and flap margin 88. Flap 56 is connected to upper surface 58 of base 52 at first side portion 84 by heat pressing, threading, or other suitable means. The outer face 82 of flap 56 presents a peritoneum blocking barrier to prevent peritoneum 27 from entering into the slurry receiving cavity 68 of projection 54. Inner face 80 presents a slurry retaining barrier, shown in FIG. 14, for retaining the slurry supporting mixture 90 within the cavity 68 of projection 54.
FIGS. 9-12, commonly numbered with FIGS. 3 and 8, depict differently sized embodiments of the prosthetic device in accordance with the present invention wherein the angle 92 from which projection 54 extends from base 52 varies depending on the angle that the inguinal canal 30 makes relative to the internal inguinal ring 28 in cases of indirect inguinal hernias. For instance, angle 92 may vary anywhere from 30° to 60°. It should also be noted in the alternative embodiments, FIGS. 9-12 that the length of the projection 54 may be varied as needed, depending on the length of the inguinal canal 30 into which the prosthetic device 50 is to be inserted. The width of projection 54 may also be varied depending on the diameter of defect 94.
FIG. 13 depicts an alternative embodiment of the prosthetic device 50' in accordance with the present invention especially designed for the repair of a double inguinal hernia. A double inguinal hernia is a hernia that presents two adjacent defects, one resulting from a defect associated with the weak spot of the internal inguinal ring 28 and the other resulting from a defect associated with the weak spot of the direct space 32. It should be noted that projection 54' extends generally perpendicular from base 52' while projection 54a extends at an angle 92' from base 52'. Projections 54', 54a' may also be varied in width and length. Base 52' may be varied in length depending on the distance of the defect associated with the internal inguinal ring 28 from the defect associated with the direct space 32.
Referring to FIG. 6, the prosthetic device 50 in accordance with the present invention may be pre-packaged in a disposable plastic insertion enabling instrument 96. The pre-packaged sterile prosthetic device 50 will enable the surgeon to choose the appropriately sized prosthetic device 50 from among many such prosthetic devices 50 present in the operating room.
Referring to FIG. 6, the insertion enabling instrument 96 for use in inserting the prosthetic device 50 into a defect 94 broadly includes hollow tube 98 and disposable obturator 100. Prosthetic device 50 is depicted as received with the hollow tube 98 for insertion into the defect 94.
Hollow tube 98 broadly includes stop 102 and shank portion 104. Shank 104 has an outer diameter slightly less than the inner diameter of the central lumen 105 of instrument receiving trocar sleeve 106. Stop 102 is comprised of two opposed trocar stop flanges 108, 110. Disposable obturator 100 is positioned inside the slurry receiving cavity 68 of projection 54 for use in positioning prosthetic device 50 in inguinal canal 30 and defect 94.
Referring to FIG. 5, defect 94 may be sized by sizing device 112. Sizing device 112 broadly includes syringe 114, leur-lock connector 116, rigid guiding catheter 118, and balloon tip 120. Syringe 114 contains a balloon tip filling medium 122 comprised of liquid or air. Balloon tip 120 includes defect measuring rings 124.
Referring to FIGS. 4 and 15, a blunt tipped, hollow, slurry filling obturator 128 may be used to inject slurry supporting mixture 90 into slurry receiving cavity 68 of projection 54.
The method for repairing of direct space and indirect space inguinal hernias broadly includes the steps of inducing carbon dioxide pneumoperitoneum in the abdominal cavity 12 of the patient; inserting the trocars through the abdominal wall 18 of the patient into the abdominal cavity 12; identifying the hernia as a direct space or an indirect space inguinal hernia; inserting the sizing device 112 into the abdominal cavity 12; sizing the hernia defect; selecting an appropriately sized prosthetic device 50; using the insertion enabling instrument 96 to insert the prosthetic device 50 into the abdominal cavity 12; placing the projection of the prosthetic device 50 through the internal inguinal ring 28; positioning the prosthetic device 50 in the inguinal canal 30; positioning the prosthetic device 50 against the inguinal wall; and using the slurry filling obturator 128 to fill the prosthetic device 50 with a slurry mixture.
Referring to FIGS. 6 and 7, trocar sleeve 126, depicted in phantom lines, is introduced into abdominal cavity 12. A laparoscope (not shown) is introduced into abdominal cavity 12 through trocar sleeve 126. The laparoscope, an illuminating optical instrument, is used to visualize the interior of the abdominal cavity 12. A camera (not shown) is placed over the eyepiece of the laparoscope and the procedure is monitored on a television screen. Trocar 19 is placed mid-abdomen, right or left, on the same side as the hernia, and an additional trocar (not shown) is placed on the opposite side. Once the surgeon uses the sharp tipped obturator to make the puncture orifices 14, 16 in the abdominal wall 18 of the patient, the obturator is removed and the trocar sleeves 106, 126 are left in the patient. Various instruments introduced into the abdominal cavity 12 of the patient through trocar sleeve 106, may be locked into place by set screws 107, 109 thereby freeing the surgeon's hands for other tasks.
Using the laparoscope the hernia is identified as a direct, an indirect or a double hernia. A grasper (not shown) inserted through instrument receiving trocar sleeve 106 is used to grab the free inferior edge of the hernial sac (not shown). A laser fiber is then used to incise the fibroareolar or fibrous tissue of the hernial sac, and the fiber is then removed from the abdominal cavity 12.
Referring to FIGS. 5 and 6, the surgeon next introduces balloon tip 120 of defect measuring device 112 into defect 94. The balloon tip 120 of rigid guiding catheter 118 is filled with a liquid or air medium 122. Balloon tip 120 accordingly expands inside defect 94 until measuring rings 124 are flush with the diameter of defect 94. The surgeon assesses the diameter of defect 94 by extrapolation from the number of millimeters of medium 122 injected. The surgeon is then able to select the appropriate size and type of prosthetic device 50 as depicted in FIGS. 3 and 8 through 13.
Once the appropriate pre-packaged prosthetic device 50 is selected, the surgeon inserts the insertion enabling instrument 96 into central lumen 105 of instrument receiving trocar sleeve 106 by means of obturator 100. Prosthetic device 50 is pushed by obturator 100 through the hollow tube 98 of the insertion enabling instrument 96, through the central lumen 105 of instrument receiving trocar sleeve 106 and into abdominal cavity 12. Prosthetic device 50 unfurls inside abdominal cavity 12. Inside the abdominal cavity 12, the projection of the prosthetic device 50 is passed through the internal inguinal ring 28 and positioned in the inguinal canal 30. The surgeon uses obturator 100 to angle projection 54 medially, right or left as the case may be, and pushes projection 54 through inguinal canal 30 stopping short of the external inguinal ring. Base 52 rests flush against the muscle wall surrounding the internal inguinal ring 28. Flange 64 is positioned against fascia 12 of abdominal cavity 12 such that flange 64 covers the weak spot associated with direct space 32.
Once positioned, the slurry receiving cavity 68 of projection 54 is filled with a slurry mixture 90 of polypropylene, abdominal contents or other suitable mixtures, to lend additional support to the area and to prevent abdominal contents from entering the cavity 68. Flap 56 is then allowed to fall over and cover slurry receiving cavity 68. The laparoscopic instruments are then removed and the abdominal viscera are allowed to fall back into place, as depicted in FIG. 14.
Although the description of the preferred embodiment has been presented, it is contemplated that various changes, including those mentioned above, could be made without deviating from the spirit of the present invention. It is therefore desired that the present embodiment be considered in all respects as illustrative, not restrictive, and that reference be made to the dependent claims rather than to the foregoing description to indicate the scope of the invention. | A method of repair of direct space and indirect space inguinal hernias and a unique prosthesis enable the use of laparoscopic surgical techniques with the benefits associated therewith, while greatly reducing the recurrence of hernial defects. The prosthetic device in accordance with the present invention is a unitary piece having an abdominal wall engaging base, a hollow projection, and a slurry retaining flap. The base includes a flange that anchors the prosthetic device against the abdominal wall and a flange that covers and gives support to the surrounding abdominal wall where direct space inguinal hernia recurrence is high. The projection, situated between the ledge and the flange, is received within the defect associated with inguinal hernias and lends support thereto. | 0 |
CROSS-REFERENCE TO RELATED APPLICATION
The present application claims the benefit of U.S. Provisional Patent Application No. 61/059,164 entitled “Apparatus and Method for Obtaining Topographical Images in a Scanning Electron Microscope”, filed Jun. 5, 2008, by inventors Edward M. James; Ye Yang; Mark Lin; Alexander J. Gubbens; and Paul Petric. The disclosure of U.S. Provisional Patent Application No. 61/059,164 is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to apparatus and methods for electron beam imaging.
2. Description of the Background Art
The two most common types of electron microscopes available commercially are the scanning electron microscope (SEM) and the transmission electron microscope (TEM). In an SEM, the specimen is scanned with a focused beam of electrons which produce secondary and/or backscattered electrons as the beam hits the specimen. These are detected and typically converted into an image of the surface of the specimen. Specimens in a TEM are examined by passing the electron beam through them, revealing more information of the internal structure of specimens.
Bright field imaging and dark field imaging are often used in the context of TEMs. A bright field image may be formed in a TEM by selecting electrons from a central diffraction spot to form the image. A dark field image may be formed in a TEM by selecting some or all of the (non-central) diffracted electrons to form the image. The selection of electrons may be implemented using an aperture into the back focal plane of the objective lens, thus blocking out most of the diffraction pattern except that which is visible through the aperture.
Dark field imaging is typically less commonly used in SEMs. In SEMs the terminology is used to describe imaging modes yielding contrast sensitive to the surface topography. “Dark field imaging” and “topographical imaging” expressions can therefore be used interchangeably. In general, dark field images are those obtained using electrons emitted from the sample surface at high polar angles and a given range of azimuthal angles. The definitions of the polar angle θ and azimuth angle φ in relation to the scattered electrons emitted from the specimen are shown by illustration in FIG. 1 . In FIG. 1 , the specimen plane is the x, y plane. The z-axis is normal to the specimen plane. This type of image preferentially shows the sample surface topography by highlighting protrusions and depressions in the surface via shadowing or highlighting. This is analogous to the contrast generated by imaging a surface from an angle as it is illuminated normally by light.
A conventional SEM dark field detection system has a below-the-lens configuration 200 as depicted in FIG. 2 . In a below-the-lens configuration 200 , so-called “external” or “side” detectors 204 are positioned below the objective lens 202 at the bottom of the electron beam column (near the specimen). Under certain conditions, secondary electrons (SE) emitted at higher polar angles (i.e. closer to the surface), which are generally more sensitive to surface topography, will preferentially reach such below-the-lens detectors 204 . Images formed with such detectors show the topography of the surface with an azimuthal perspective defined by the detector positioning with respect to the primary beam optic axis and the sample/wafer plane.
Unfortunately, the below-the-lens configuration is incompatible with final (objective) lens arrangements that immerse the specimen in magnetic and/or electric fields. These fields are needed for minimizing lens aberrations and obtaining the best resolution images, but they interfere with the collection efficiency of below-the-lens detectors 204 .
In addition, the polar angle discrimination threshold is not well controlled for such below-the-lens detectors 204 because the electron energy and emission azimuth can affect the polar angle acceptance of the detector 204 .
Dark field imaging may also be performed by tilting the sample/wafer plane normal vector away from the primary beam optic axis. Such tilting may be accomplished by tilting the wafer or column and has the effect of changing the angle of incidence of the primary beam. The secondary electron signal detected, either by a side channel detector or a conventional in-lens detector, shows topological DF contrast according to how the primary beam angle interacts with the surface features on the sample/wafer.
Various previous behind-the-lens configurations for an SEM dark field detection system have been employed that are compatible with final lenses with immersion electromagnetic fields at the specimen. These previous configurations distinguish between the different angular components of the secondary-electron emission after it has been captured by the electro-magnetic field and traveled up into the column beyond the final lens.
A typical behind-the-lens configuration 300 for an SEM dark field detection system is depicted in FIG. 3 . A typical behind-the-lens configuration 300 uses off-axis detectors 304 similar to those shown in FIG. 3 . These may be separated (as shown) or joined together to form a segmented detector. These detectors 304 are located “behind” the objective lens 302 . In other words, the detectors 304 are located on the opposite side of the objective lens 302 to the specimen. Various detector geometries and associated electron optics have been used previously to detect scattered electrons with polar angle discrimination. However, behind-the-lens configurations have generally shown inferior dark-field (topographical) contrast compared to below-the-lens implementations.
SUMMARY
One embodiment relates to an electron beam apparatus configured for dark field imaging of a substrate surface. A source generates a primary electron beam, and scan deflectors are configured to deflect the primary electron beam so as to scan the primary electron beam over the substrate surface whereby secondary and/or backscattered electrons are emitted from the substrate surface, said emitted electrons forming a scattered electron beam. A beam separator is configured to separate the scattered electron beam from the primary electron beam. The apparatus includes a cooperative arrangement which includes at least a ring-like element, a first grid, and a second grid. The ring-like element and the first and second grids each comprise conductive material. A segmented detector is positioned to receive the scattered electron beam after the scattered electron beam passes through the cooperative arrangement.
Another embodiment relates to a method for dark field imaging of a substrate surface. Other embodiments, aspects and features are also disclosed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram depicting a conventional definition of angles.
FIG. 2 is a three-dimensional depiction of an SEM dark field detection system with a previous below-the-lens configuration.
FIG. 3 is a schematic diagram of a generic SEM dark field detection system with a behind-the-lens configuration.
FIG. 4A is a schematic diagram of an electron beam column for an apparatus in accordance with an embodiment of the invention.
FIG. 4B is a schematic diagram of a detection system for an apparatus in accordance with an embodiment of the invention.
FIG. 5 is a schematic diagram of a dodecapole deflector in accordance with an embodiment of the invention.
FIG. 6 is a schematic diagram of a detector segmentation in accordance with an embodiment of the invention.
DETAILED DESCRIPTION
The present application discloses a behind-the-lens-dark-field (BLDF) configuration which is designed to act as a detector in a scanning electron microscope (SEM). The BLDF configuration has multiple detection elements that are designed to efficiently collect signals for the generation of images giving multiple perspectives of a surface of a sample substrate. The multiple perspectives include so-called dark-field (DF) and bright-field (BF) perspectives.
DF images typically highlight wafer topography. DF images primarily use the signal from secondary electrons (SE) and/or backscattered electrons (BSE) emitted from the sample with higher polar angles (i.e. with trajectories closer to the surface). BF images (which are more conventional than DF images) typically highlight material contrast and provide higher-resolution, planar images of the sample surface. BF images primarily use SE and/or BSE that are emitted from the sample with lower polar angles (i.e. with trajectories closer to the normal vector for the surface).
Applicants believe that embodiments of the present invention improve upon previous BLDF configurations. In particular, improved performance is provided in dark field purity, flexibility, image uniformity, and/or signal-to-noise ratio (SNR).
Regarding dark field purity, it is desirable to have the capability to better separate signals of secondary electrons emitted at higher polar angles from secondary electrons emitted at lower polar angles. It is further desirable to have an improved capability to discriminate signals corresponding to secondary electrons emitted at different azimuthal angles.
Regarding flexibility, it is desirable to have the aforementioned improved signal separation over a wide range of primary beam conditions. Such primary beam conditions may then be optimized or adjusted to reduce deleterious effects, such as sample charging, while maintaining adequate dark-field purity.
Regarding image uniformity, it is desirable to produce images with relatively uniform contrast, brightness and DF content across the field of view. This improves image aesthetics and also improves the reliable performance of image processing algorithms such as automatic defect review (ADR) procedures.
Regarding the signal-to-noise ratio (SNR), it is desirable to produce images with improved SNR in comparison to previous detector configurations.
FIG. 4A is a schematic diagram of an electron beam column for an apparatus in accordance with an embodiment of the invention. As seen, source 401 generates a primary beam 402 of electrons. The primary beam 402 passes through a Wien filter 404 which is configured to separate the primary beam 402 from the secondary electron (SE) and/or backscattered electron (BSE) beam 412 .
Scanning deflectors 406 and focusing electron lenses 407 are utilized. The scanning deflectors 406 are utilized to scan the electron beam across the surface of the wafer or other substrate sample 410 . The focusing electron lenses 407 are utilized to focus the electron beam into a beam spot on the surface of the wafer or other substrate sample 410 . In accordance with one embodiment, the focusing lenses 407 may include an immersion lens which is configured with a variable extraction field to control the acceleration of emitted electrons away form the sample and control the level of polar angle discrimination.
Secondary electrons and/or backscattered electrons are scattered or extracted from the wafer/sample 410 . These secondary and/or backscattered electrons are exposed to the action of the final (objective) lens by way of the electromagnetic field 408 . The electromagnetic field 408 acts to confine the secondary and/or backscattered electrons to within a relatively small distance from the primary beam optic axis and to accelerate these electrons up into the column. In this way, a scattered electron beam 412 is formed from the secondary and/or backscattered electrons.
The Wien filter 404 is an optical element configured to generate electrical and magnetic fields which cross each other. The Wien filter 404 deflects the scattered electron beam 412 from the optic axis of the primary beam to a detection axis. This serves to separate the scattered electron beam 412 from the primary beam 402 .
For example, in one implementation, the electron source 401 may be at negative five kilovolts (−5 kV), and the stage for the wafer/sample 410 may be at negative four kilovolts (−4 kV), while the bulk of the column is at electrical ground. This is a convenient way to achieve a primary beam landing energy of 1 keV, which is representative for low-landing-energy SEM imaging applications. In such an implementation, a grounded grid (see 414 in FIG. 5B ) may be used at the entrance of the detector, and a scintillator (see 422 in FIG. 5B ) in the detector may be held, for example, at positive five kilovolts (+5 kV).
FIG. 4B is a schematic diagram of a detection system for an apparatus in accordance with an embodiment of the invention. As discussed above, the Wien filter 404 deflects the scattered electron beam 412 onto the optic axis for the detection system (the detection axis).
The scattered electron beam 412 may pass through one (or more) grounded conductive mesh(es) or grid(s) 414 . The electrically grounded grid(s) 414 function to screen or shield a main portion of the scattered beam 412 from the effects of any fields in the main column, and to shield a main portion of the primary beam from the effects of any fields in the detection system (see FIG. 4A ). In other words, the grounded grid(s) 414 serves to prevent any undesirable stray field interference between the main column and detection system 412 - 430 .
In accordance with an embodiment of the invention, the scattered beam 412 passes through an additional electron deflector 416 which is a dodecapole (12-pole) deflector. The configuration of the dodecapole deflector is described further below in relation to FIG. 5 . The electron deflector 416 may be preferably configured to minimize any undesirable movement of the scattered beam 412 which is caused by the scanning deflectors 406 in the main column (see FIG. 5A ). It may also be configured to align the scattered beam accurately to the final detection element (the scintillator 422 ).
The scattered beam 412 may then pass through a pair of biased conductive grids 418 and 420 with appropriate voltages applied thereto.
When combined with a conductive ring-like structure 416 , the grids 418 and 420 may be configured to form an electrostatic lens in a first operating mode or to act as an energy filter in a second operating mode. The preferred cooperative arrangement includes the ring-like conductive element and the two biased grids with close separations (on the order of millimeters, or less than one centimeter) therebetween. The middle element of the three elements (the two biased grids and the conductive ring) may be defined as the electron lens grid 418 . In one embodiment, the conductive ring-like structure may comprise a dodecapole deflector when it is used as the electron deflector 416 and positioned sufficiently close to the electron lens grid 418 , as shown in FIG. 4B . To operate as the ring-like conductive element of the combination, the dodecapole plate voltages should be kept at substantially lower voltages than the electron lens grid 418 .
In the first operating mode, the voltage applied to the electron lens grid 418 may be varied to focus (converge) or defocus (diverge) the scattered electron beam 412 . By such operation, the diameter of the scattered beam 412 may be adjusted at subsequent planes within the detection system, such as the plane at the surface of a scintillator in the detection system. This allows for the compensation of diameter changes for the scattered beam 412 that may take place as a side effect of when the primary beam 402 is adjusted to best image a particular sample 410 .
Typically, the ring-like conductive element (for example, the dodecapole) and the second biased grid 420 are kept relatively close to ground, but this is not mandatory as a lens will be formed as long as there are substantial voltage differences between the grids and the ring-like element. In one example, to form a diverging electrostatic lens, the electron lens grid (mesh) 418 may be at negative three kilovolts (−3 kV), while the dodecapole deflector 416 (or other ring-like element) and the second biased grid 420 are near or at electrical ground. Such a configuration operates to diverge (defocus or spread out) the scattered electron beam 412 , as depicted in FIG. 4B . In another example, to form a converging electrostatic lens, the electron lens grid 418 may be at positive three kilovolts (+3 kV), while the dodecapole deflector 416 (or other ring-like element) and the second biased grid 420 are near or at electrical ground. Such a configuration operates to converge (focus) the scattered electron beam 412 .
Advantageously, the above-described three-element lens is very compact and may be used to either diverge or converge the scattered electron beam 412 within the detection system.
In the second operating mode, the three-element arrangement may be configured to function as an energy filter. A negative voltage on either of the two biased grids may be used to slow the electrons of the scattered electron beam. At a certain voltage level, the slower electrons are repelled and do not pass to the detection elements further down in the detection system. Note that either of the two biased grids ( 418 or 420 ) may be used as the active element. Different filter characteristics may be achieved in this way. In one example, the ring-like element and the first biased grid 418 may be held at or near electrical ground while a negative voltage (for example, minus four kilovolts) may be applied to the second biased grid 420 (such that the second biased grid is the active grid). In another example, the ring-like element and the second biased grid 420 may be held at or near electrical ground while a negative voltage (for example, minus four kilovolts or −4 kV) may be applied to the first biased grid 418 (such that the first biased grid is the active grid). In an alternative arrangement, the scattered beam 412 may encounter the two biased grids first and then the conductive ring-like element.
Advantageously, by filtering out the lowest energy scattered electrons, the signal passing to the detective elements is typically less sensitive to charging and/or contamination on the sample. An example of an arrangement of detective elements comprises the detective element stack shown in FIG. 4B .
The detective element stack shown in FIG. 4B includes a scintillator 422 , a segmented light pipe 424 , and a segmented photomultiplier tube (PMT) 426 . Advantageously, the detective stack disclosed herein provides for an efficient signal path with improved detective quantum efficiency (DQE). Higher DQE yields an improved signal-to-noise ratio (SNR) for a given scattered electron beam 412 signal from the sample/wafer.
The scintillator 422 may comprise, for example, an aluminum-coated Yttrium Aluminum Garnet (YAG) substrate. The aluminum coating is a thin conductive coating so it may be set to a high electrical potential without substantially charging. Alternatively, a coated Yttrium Aluminum Perovskite (YAP) crystal may be used for the scintillator 422 . Use of these scintillator types provides a robust, high-gain first element to the signal acquisition process.
In accordance with one embodiment, the scintillator 422 may be configured as a single piece and the detector segmentation may be achieved using a segmented light pipe 424 , for example. The segmented light pipe 424 may be configured to effectively segment the scintillator into five or more channels. For instance, the segmentation may be accomplished using a white, optically opaque epoxy, which holds the segments in place while preventing optical cross-talk between them.
In accordance with another embodiment, the scintillator 422 itself may be divided into two or more segments. This advantageously reduces cross talk between the channels of the instrument, thereby maintaining integrity of the signal as a function of detected position. It may also be configured to reduce optical signal loss through the edges of the scintillator. For example, in the case where the scintillator 422 is divided into two segments, a center segment may be separated from an outer segment using an opaque epoxy. Other implementations may replace the epoxy separation with a solid wall separation. The solid wall separation may extend throughout the detective element stack to keep the channels well separated.
An embodiment of the invention may utilize a segmented optical coupling (segmented light pipe) 424 . Use of such a segmented optical coupling 424 is optional in that other embodiments may not include one. For example, the segmented optical coupling 424 may comprise a thin optical plate, which may be made of a high refractive index material such as sapphire, bonded to the scintillator 422 using a clear, transmissive epoxy, or, alternatively, clamped to the scintillator with optical grease optionally applied between the elements. The plate may be segmented to reflect the desired channel geometry. One example of such segmentation is shown in FIG. 6 . The individual segments of the optical coupling 424 may be, for example, glued together using a white, optically opaque epoxy. Advantageously, the high refractive index and small thickness of a sapphire plate provides for more efficient optical coupling and a compact arrangement, while also resisting electrical breakdown when a high voltage applied to the scintillator's conductive surface 422 . In addition, this design results in reduced optical cross talk. This enables the detector to operate with increased detective quantum efficiency (DQE).
Alternative embodiments may utilize different optical materials or coupling glues (which may be selected based on the scintillator chosen and its refractive index). The optical plate segments may also be separated with a solid wall of insulating material. Such a wall may extend throughout the whole detective element stack to keep channels separated. The wall may also be made reflective via use of an insulating multilayer coating.
Another embodiment may utilize the scintillator itself as the optical coupling medium. In this case, the scintillator may be made substantially thicker in order to hold off (provide a layer insulating against) the high voltage between its conductive coating and the rest of the device.
A segmented photomultiplier tube (PMT) 426 may be bonded to the back of the optical coupling plate 424 . For example, a multi-anode PMT may be configured with a photocathode entrance window and a dynode array behind the cathode. The array of dynodes (for example, an 8×8 array of dynodes) may be utilized to effectively segment the PMT. The outputs of the multiple dynodes may be electrically tied together to form groupings that correspond to the desired spatial segmentation of the detector. In accordance with one implementation, light entering the multi-anode PMT 426 is preferentially directed down a signal chain into one of five channels, the five channels corresponding to a center detector segment and four outer segments, as depicted in FIG. 6 . In one implementation, the multi-anode PMT 426 may be bonded to the back of a sapphire optical coupling plate using clear epoxy. Alternatively, clamping may be used, with or without optical coupling grease. Mounting of the multi-anode PMT 426 in vacuum directly to the back of the scintillator/optical plate stack is very optically efficient, allows less opportunity for inter-segment cross talk or noise pick-up, and is very compact. Alternatively, the segmented PMT 426 may have a segmented photocathode entrance window, or may consist of miniature individual PMTs bonded to the back of the optical coupling plate 424 in an array, or other desired arrangement.
Finally, a multi-purpose circuit board (including pre-amplifier circuitry 428 ) may be mounted on top of the PMT 426 and within the vacuum environment. The circuit board may provide high voltage to operate the PMT 426 and may also have a voltage divider to split the voltage correctly across the dynode array. The circuit board may also be configured to group the output signals from the many (for example, sixty-four) dynodes of the multi-anode PMT 426 into several (for example, five) signal paths or chains For example, in the implementation with five signal paths, the five signal paths may correspond to a center detector segment and four surrounding outer segments. The power and signal connections may be fed to vacuum feedthroughs and onto other electronics components outside of the vacuum.
FIG. 5 is a schematic diagram of a dodecapole deflector in accordance with an embodiment of the invention. As discussed above, the electron deflector 416 in the detection apparatus may comprise such a dodecapole deflector. As seen, the dodecapole deflector comprises twelve conductive plates. The geometry (relative dimensions) of the plates is designed such that the dodecapole mimics two dipole elements when four appropriate voltages are applied.
Voltages may be applied to the twelve plates as shown in FIG. 5 to generate a first dipole (x-dipole) in the “x” direction and a second dipole (y-dipole) in the “y” direction, wherein the x and y directions are perpendicular to each other. The strength and direction of the x-dipole would depend on the voltage X and the geometry of the plates, while the strength and direction of the y-dipole would depend on the voltage Y and the geometry of the plates. As seen, the three plates labeled “+X” would have +X volts applied to them, and the three plates labeled “−X” would have −X volts applied to them. These six plates would effectively generate the x-dipole (in the horizontal direction in FIG. 5 ). Meanwhile, the three plates labeled “+Y” would have +Y volts applied to them, and the three plates labeled “−Y” would have −Y volts applied to them. These six plates would effectively generate the y-dipole (in the vertical direction in FIG. 5 ).
In particular, a DC-type (direct or steady) deflection may be used to align the scattered beam 412 correctly with the subsequent detector elements, and an AC-type (alternating) deflection may be applied to compensate for undesirable scanned movement of the scattered beam 412 entering the detection system. This combination of fields may be used to improve the image symmetry and uniformity in a way that does not adversely affect the primary beam 402 .
Advantageously, the use of the 12 deflection plates allows for a good approximation to perfect X and Y dipoles to be produced in a very compact deflector. Although electrostatic deflection is being used in the “dodecapole” deflector shown in FIG. 5 , an alternative embodiment may employ magnetic deflection using pairs of saddle coils or similar means. Other alternative arrangements may use more than twelve plates to form the deflector. For example, an icosopole (20-plate) deflector may be used.
FIG. 6 is a diagram of a detector segmentation in accordance with an embodiment of the invention. As shown in FIG. 6 , one or more elements of the detective stack may be segmented into five channels. The five channels including a center channel 602 and four outer channels 604 - 1 , 604 - 2 , 604 - 3 , and 604 - 4 . For example, the optical coupling (light pipe) 424 may be segmented as shown in FIG. 6 . In addition, the dynodes of the segmented PMT 426 may be grouped to effectively form this segmentation. In alternative embodiments, different segmentations may be implemented.
Advantageously, the above-disclosed apparatus improves topographical imaging for a behind-the-lens-dark-field (BLDF) geometry in the following ways.
Regarding dark field purity, the segmentation implementation in the BLDF detective elements will reduce cross-talk between the detector segments that sample secondary and/or backscattered electrons that were emitted at differing polar and azimuthal angles. This results in improved topographical contrast. The enhanced detector DQE enables weaker topographical contrast to be visible at viable SNR levels. The above-described three-element grid and ring arrangement operating in a lens mode enables the scattered beam to be focused or diverged to an optimal size at the scintillator plate, ensuring that the higher-polar-angle secondary electron emission is directed towards the outer detector segments. Finally, the use of the three-element arrangement in an energy filter mode provides for the lower-energy secondary electrons to be filtered out of the image. Filtering the lower-energy secondary electrons can advantageously reduce mixing between electrons and minimize non-topographical image contrast.
Regarding flexibility, the three-element arrangement in the lens mode may be used to advantageously compensate for the effect on the scattered beam caused by using a variety of conditions for the primary beam set-up and focusing. In addition, the enhanced detector DQE enables weaker signals to be imaged at adequate SNR, thereby allowing use of lower beam current or higher imaging throughput (by way of less image acquisition time or less frame averaging).
Regarding image uniformity, the optional dodecapole deflection element may be used to correct for image non-uniformity due to, for example, the undesirable effects of the scattered beam caused by scanning of the primary beam, or a sub-optimal location of the detector plane. For large fields of view (FOV), this may advantageously reduce spurious gray level variation towards the edges of the FOV. The three-element arrangement in the filter mode may be advantageously used to filter out lower energy secondary electrons which are more susceptible to having their trajectories disturbed by charging of the substrate surface. This can reduce charging-related image artifacts. Furthermore, the improved flexibility to use an extended range of primary beam landing energies, extraction fields and/or beam currents increases the capability to find SEM set-ups that minimize sample/wafer charging and the image artifacts the charging produces.
Finally, regarding the SNR, the enhanced DQE enables the imaging of weaker signals at adequate SNR.
In the above description, numerous specific details are given to provide a thorough understanding of embodiments of the invention. However, the above description of illustrated embodiments of the invention is not intended to be exhaustive or to limit the invention to the precise forms disclosed. One skilled in the relevant art will recognize that the invention can be practiced without one or more of the specific details, or with other methods, components, etc. In other instances, well-known structures or operations are not shown or described in detail to avoid obscuring aspects of the invention. While specific embodiments of, and examples for, the invention are described herein for illustrative purposes, various equivalent modifications are possible within the scope of the invention, as those skilled in the relevant art will recognize.
These modifications can be made to the invention in light of the above detailed description. The terms used in the following claims should not be construed to limit the invention to the specific embodiments disclosed in the specification and the claims. Rather, the scope of the invention is to be determined by the following claims, which are to be construed in accordance with established doctrines of claim interpretation. | An electron beam apparatus is configured for dark field imaging of a substrate surface. Dark field is defined as an operational mode where the image contrast is sensitive to topographical features on the surface. A source generates a primary electron beam, and scan deflectors are configured to deflect the primary electron beam so as to scan the primary electron beam over the substrate surface whereby secondary and/or backscattered electrons are emitted from the substrate surface, said emitted electrons forming a scattered electron beam. A beam separator is configured to separate the scattered electron beam from the primary electron beam. The apparatus includes a cooperative arrangement which includes at least a ring-like element, a first grid, and a second grid. The ring-like element and the first and second grids each comprises conductive material. A segmented detector assembly is positioned to receive the scattered electron beam after the scattered electron beam passes through the cooperative arrangement. Other embodiments, aspects and features are also disclosed. The apparatus is configured to yield good topographical contrast, high signal to noise ratio, and to accommodate a variety of scattered beam properties that result from different primary beam and scan geometry settings. | 7 |
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This utility application claims priority from U.S. Provisional Patent Application No. 60/506,447 filed Sep. 26, 2003.
FIELD OF THE INVENTION
[0002] The present invention relates generally to protective headgear devices, and more particularly to a shield for a ball cap to protect the wearer's head.
BACKGROUND OF THE INVENTION
[0003] Baseball and softball are activities that are enjoyed by millions of Americans every year. From little league to recreational softball, and collegiate to semiprofessional and professional leagues, baseball has earned the nickname of our national pastime. The game is played with a ball that is pitched to a batter who attempts to hit the ball and run around three bases before reaching the starting place, home plate. Fielders attempt to catch the ball before it hits the ground, or advance the ball to the base that a runner is approaching. Fielders patrolling the bases can get the runner “out” if they tag the runner in some cases, or tag the base prior to the runner reaching the base in other cases. The many rules of baseball are complicated and the details of the rules of play are beyond the scope of the present invention, but some rules discussed below are pertinent to the present discussion.
[0004] A baseball is formed of several layers, or wrappings encased in a two-piece leather cover. The heart of the ball is a composite cork/rubber center surrounded by two layers of rubber, one red, the other black. The first wrap around the core is a four-ply gray wool winding. The second wrap is a three-ply white wool winding. The third wrap is a three-ply gray wool winding. The fourth and final wrap is a fine cotton string forming a finish winding. The windings are done on machines and each ball is measured and weighed after each winding. Each half of the leather cover is alum tanned to give it the white color, and cut in a FIG. 8 . The two halves are double stitched by hand using 10/5 red thread. Completed balls are tested for size, weight and coefficient of restitution.
[0005] A finished baseball weighs five ounces and has a coefficient of restitution of approximately 0.503 and a compression deflection at 500 psi of 0.363 inches. The many tight windings of a baseball's interior gives the ball a hardness that is necessary to generate the four hundred foot home runs that major league hitters are capable of. The velocity of a pitched baseball reaches speeds in the professional leagues of up to one hundred miles per hour, or one hundred forty feet per second. Balls struck by a bat can exceed this velocity twenty percent or more, resulting in a batted ball velocity of up to one hundred and twenty miles per hour, or approximately one hundred sixty five feet per second. At five ounces, a ball traveling one hundred sixty five feet per second has a potentially lethal momentum if it should strike a player in the head. The pitcher, who stands a mere sixty feet six inches from the batter, is at most risk. A ball traveling one hundred sixty five feet per second will reach the pitcher in just over one third of a second. Even professional athletes with highly advanced motor functions have difficulty reacting flawlessly under these conditions, and an error can result in severe injury to the head and face.
[0006] Traditional baseball and softball uniforms include a cloth cap with a bill on the front and a logo on the forward-facing top portion. While batters wear protective helmets to protect them against pitched balls, there is no protective gear used to safeguard the pitcher from batted balls that can reach speeds greater than pitched balls. Moreover, the motion that a pitcher undergoes in delivering a ball at the velocities needed to be successful often leave the pitcher off balance or turned slightly away from the batter, further inhibiting the pitcher's ability to react quickly to a ball hit by the batter toward the pitcher's head. In addition, most pitchers during delivery of the pitched ball lean their head forward in a downward facing direction exposing the forehead and scalp to a direct impact from a batted ball. This has led to serious injury to pitchers who were unable to avoid a batted ball hit directly back toward the pitcher's head. The prior art lacks a simple, unobtrusive protective element that can be worn with a traditional ball cap and can protect a pitcher or other fielder from being struck in the head with a batted or thrown baseball or softball.
SUMMARY OF THE INVENTION
[0007] A protective ball cap shield is characterized by a curved protective overlay for a ball cap that secures to the frontal portion of the cap and provides protection from oncoming batted balls. In a first embodiment, the shield is made of plastic and conforms with the contour of the frontal portion of the ball cap above the bill, with rearwardly extending flaps that extend partially around the ball cap. The flaps include mountings for securing an adjustable strap that tightens around the rear portion of the cap and wearer's head to secure the shield in place. A liner of foam or other energy absorbing material can be included on the lower inner surface of the shield. In addition, the shield can be matched in color to the ball cap and include a logo similar to the logo on the cap to simulate the front of the cap and render the shield substantially undetectable from a distance. In a second embodiment, the shield can be disposed inside the cap at the forward portion behind the logo, hidden from view. A hook and loop securing system, such as VELCRO®, may be used to anchor the shield inside the cap in the proper position, and a liner of foam or other energy absorbing material can be included on the surface of the shield adjacent the wearer's head. In a third embodiment, the shield can be sewn into a forward location of the ball cap between two layers of material forming the ball cap. In yet another embodiment, an optional eye guard is included.
[0008] While the disclosure describes the invention with respect to baseball caps, the invention is not limited to this exemplary application and is equally applicable to caps used in other sports.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a side view of a first embodiment of the ball cap shield of the present invention;
[0010] FIG. 2 is a front view of the ball cap shield of FIG. 1 ;
[0011] FIG. 3 is a rear view of the ball cap shield of FIG. 1 ;
[0012] FIG. 4 is a side view of a second embodiment of the ball cap shield of the present invention;
[0013] FIG. 5 is a bottom view of the ball cap shield of FIG. 4 ;
[0014] FIG. 6 is a side view of a third embodiment of the ball cap shield of the present invention;
[0015] FIG. 7 is a side view of a fourth embodiment of the ball cap shield of the present invention;
[0016] FIG. 8 is a side view of a fifth embodiment of the ball cap shield of the present invention;
[0017] FIG. 9 is a side view of the fifth embodiment of the ball cap shield of the present invention including a bill extension;
[0018] FIG. 10 is a side view of the fifth embodiment of the ball cap shield of the present invention including a bill extension shorter than that shown in FIG. 9 ;
[0019] FIG. 11 is a side view of a sixth embodiment of the ball cap shield of the present invention;
[0020] FIG. 12 is a bottom view of the sixth embodiment of FIG. 11 ;
[0021] FIG. 13 is a side view of an seventh embodiment of the ball cap shield of the present invention;
[0022] FIG. 14 is a side view of an eighth embodiment of the ball cap shield of the present invention;
[0023] FIG. 15 is a side view of a ninth embodiment of the ball cap shield of the present invention; and
[0024] FIG. 16 is a top view of the ninth embodiment of the ball cap shield of FIG. 15 .
DETAILED DESCRIPTION OF THE INVENTION
[0025] FIGS. 1-3 illustrate a ball cap shield 10 formed of a continuous plastic panel shaped to conform with the contour of a baseball cap 20 . The shield 10 has a rounded frontal portion 30 with rearwardly extending peripheral flaps 40 extending from each side. The front surface curves upwardly and rearwardly transitioning to an upper surface 50 that preferably extends up to a cap's button 60 on the cap's upper surface 70 . The rear or trailing edge 80 of the shield 10 slopes downwardly and rearwardly along both lateral sides terminating at the bottom edge 90 of the shield 10 to form an angled juncture 100 defining the peripheral flaps 110 . Each flap 110 may preferably include a vertically oriented slot 120 sized for receiving a strap 130 therethrough. A strap 130 fed through both vertically oriented slots 120 and adjustably securable via a clasp 140 or hook and loop fastener system secures the shield 10 about the wearer's head on the outside of the ball cap 20 . A third slot (not shown) on the upper surface 50 of the shield 10 at a rear edge 150 permits a second strap 160 to connect orthogonally to the original strap 130 and provide additional support. A clasp, releasable clip, snap, buckle, or VELCRO® straps can be used to connect the straps together and secure the shield 10 in the proper position.
[0026] The straps 130 , 160 may be elastic or non-elastic, and may also be secured to the shield 10 by alternative modes such as rivets, adhesives, or hooks. In an alternative embodiment, the flaps 40 of the shield 10 are resiliently biased inwardly toward the ball cap's interior such that they grip the wearer's head through the ball cap 20 without additional straps or securing means. The resiliency of the flaps provides for easy doffing and removal, where the wearer spreads the flaps apart before placing the shield 10 on the ball cap 20 , and the flaps' 40 resilient shape compresses against the sides of the ball cap 20 and secures the shield 10 to the cap 20 and/or the user's head.
[0027] The shield 10 is preferably formed of a dense polymer with impact absorbing capability such as polypropylene, polystyrene, or suitable thermoplastic that can be formed into curved configuration to conform with the ball cap's exterior surface and retains a shape memory to maintain the desired shape. The curved configuration can include some abrupt surface changes to provide a dynamic appearance, such as that shown in FIGS. 15 and 16 . Other materials and composites may be substituted provided they possess the requisite shape memory and are of sufficient rigidity and impact resistance to provide protection from a baseball or softball traveling at high velocity. The shield 10 in some embodiments may include a logo 170 or insignia of the team that overlays the logo of the ball cap and is of a matching color with the ball cap 20 to provide a facade that resembles the front of the ball cap.
[0028] The interior or concave surface 180 of the shield 10 may be supplied with padding 190 to further absorb any impact and improve comfort. And, the interior surface 180 may be equipped with patches or strips of hook and loop fastener material 190 that cooperates with complimentary patches 200 or strips located on the exterior of the ball cap to releasably secure the shield 10 to the ball cap's exterior. Moreover, the hook and loop patches can replace the straps 130 , 160 or resilient flaps 40 discussed above, or used in combination with the straps and/or flaps to provide a secure coupling of the shield 10 and cap 20 .
[0029] The shield 10 may include, in an alternative embodiment, a forwardly projecting bill cover 210 ( FIG. 8 ) that overlays the bill 220 of the ball cap 20 and further secures the shield 10 to the cap 20 . The bill overlay 210 is preferably integrally formed with the shield 10 and colored to match the bill 220 of the cap 20 . The bill cover 210 acts as a gusset that provides increased structural integrity to the shield. In addition, this option provides further protection for the wearer as the bill 220 customarily is worn just above the eyes and the projection 210 extends the shield's coverage to the eye socket area. This is particularly important where a pitcher's head rotates toward the ground during deliver, exposing the forehead and scalp to an oncoming batted ball. Moreover, the natural instinct of a player when a projectile is headed for the face region is to duck, lowering the face as the hands go up to protect the facial area. The bill projection's expands the area of protection as the player ducks down, protecting the eyes and nose area. To secure the bill projection 210 to the cap bill 220 , hook and loop fastener material may be placed on the underside of the shield's bill projection and the upper surface of the cap's bill, where the complimentary materials serve to releasably fasten the two surfaces together. Hooks, clips, rivets, snaps, buttons, or other fasteners could also be used to releasably or permanently affix the shield bill projection 210 to the upper surface of the ball cap. Likewise, as discussed above the strap 130 fed through both vertically oriented slots 120 and adjustably securable via a clasp or hook and loop fastener system secures the shield 10 about the wearer's head on the outside of the ball cap 20 .
[0030] A second embodiment of the present invention is depicted in FIGS. 4 and 5 illustrating a ball cap shield 10 a that secures inside the ball cap 20 . This embodiment employs essentially the same shape as the first embodiment, but secures underneath the ball cap 20 in the forward area adjacent the wearer's forehead. To secure the shield 10 a inside the ball cap 20 , the shield may incorporate the hook and fastener material 230 along external regions that cooperate with complimentary regions of hook and fastener material disposed on interior locations of the ball cap. Alternatively, the shield 10 a can be secured with snaps (not shown) on the external surface that cooperate with their complimentary components affixed to the underside of the ball cap 20 , or by inserting the shield 10 a into a pocket inside the ball cap 20 specifically sized to receive the shield. Here, the shield 10 a is completely hidden from view underneath the ball cap 20 , eliminating the need for coloring the shield or placing a logo 170 on the shield. In this embodiment, the shield 10 a may optionally be provided with a bill projection that extends substantially coextensive with the bill 220 of the ball cap 20 on the under side of the bill. As before, the bill projection may be affixed to the cap bill by various methods previously discussed, including hook and fastener material, snaps, clips, and the like, or can be inserted into a large pocket.
[0031] The shield of the present invention may also be incorporated directly into the ball cap by adding a second layer 240 of material to the ball cap 20 , and then sandwiching the shield 10 a between the ball cap original layer and the added second layer 240 of material. As shown in FIG. 6 , the second layer of material 220 may be placed over the shield 10 a and a seam 250 sewn around the shield 10 a to create a pocket on the ball cap's exterior that holds the shield in place. In this embodiment the shield becomes a permanent component of the ball cap that is not removed or separated from the cap. This feature has the benefit that the shield cannot be lost, dislodged, fall off or loosen about the wearer's head, but rather is always maintained in the proper position and orientation without the need for other fastening means.
[0032] In yet another embodiment of the invention shown in FIG. 7 , the peripheral flaps 40 a on the shield 10 can be enlarged to extend downward and rearward in order to protect and cover the wearer's ears. The ears are easily damaged by impact and the temple around the ear is very susceptible to brain injury in the event of impact or trauma. By extending the protection of the shield of the present invention to the ears and surrounding area, the benefits provided by the present invention are expanded. And, the use of padding in the area of the ears provides additional protection as well as comfort when the resiliency of the ear flaps is used in securing the shield.
[0033] FIG. 8 illustrates another embodiment of the present invention, wherein the shield 10 attaches to the cap's exterior using patches of VELCRO® 200 spaced about the cap's lower edge and corresponding patches of VELCRO® 190 at the lower edge of the shield 10 . In FIG. 9 , a bill extension 210 is incorporated into the shield 10 to provide additional structural strength and protection. The bill extension 210 is preferably integrally formed with the shield 10 into a single unit and acts as a gusset to increase the shield's strength. As shown in FIG. 10 , it may be preferable to shorten the length of the bill extension 210 a to facilitate the attachment of the shield, to reduce its weight, and to provide the gusset strength. It can be used without additional attachment means, or the shield can be secured with means discussed above, such as straps, VELCRO®, or the like.
[0034] In FIGS. 11 and 12 , a shield 10 b is formed by individual plates 300 applied to the cap's interior and secured with VELCRO® strips 310 . The plates 300 that form the shield can be made of a polymer or other impact resistant material such as Kevlar, where the plates are shaped to conform with the cap's interior to protect the wearer. Strips of VELCRO® fastener material are sewn into the cap's interior and adhered to the plate's outer surface to facilitate the attachment of the plates. Alternatively, the plates can be sewn into the cap as discussed above with respect to FIG. 6 .
[0035] In FIG. 13 , another embodiment is disclosed wherein the protective shield 10 is reinforced by incorporating a plurality of gussets 330 or projections along an exterior surface. The projections provide impact-absorbing capability to disperse energy from contact with a moving object to further protect the wearer.
[0036] Still another alternative to the present invention is the incorporation of an eyeguard 400 to the shield 10 that extends downward from the shield to protect the wearer's eyes as shown in FIG. 14 . The eyeguard 400 may be transparent for night games or darkened to provide sun protection in day games. Securing the eyeguard 400 to the shield 10 is preferably achieved in a manner that provides no wiggle or play between the shield and eyeguard that could distract the wearer. An example of a rigid method of securing the eyeguard 400 include snaps 410 disposed on an upwardly projecting flap 420 that cooperate with complimentary snap-receiving members on the ball cap to removably attach the eye shield 400 to the cap.
[0037] From the foregoing description of the exemplary embodiment of the present invention, one of ordinary skill in the art will readily discover alternative embodiments within the scope of the present invention. Accordingly, the invention is not limited to the embodiments discussed, but rather determined by the claims appended hereto. | A shield adapted for use with a baseball cap or caps used in other sports is disclosed to protect a pitcher or fielder from a batted or thrown baseball or softball. A panel is shaped to conform with a front surface of a ball cap and is secured with straps or other means on the outer surface of the ball cap or, alternatively, on the inner surface of the ball cap. The shield is formed of a sheet or panel of impact absorbing plastic that protects the user from trauma in the event of a collision with a traveling ball or other object. | 0 |
This application is a continuation, of application Ser. No. 181,440, filed Aug. 25, 1980, now abandoned,
FIELD OF THE INVENTION
The present invention is directed to an improvement in wheeled floor jacks and is especially concerned with an attachment for or accessory to such jacks.
BACKGROUND OF THE INVENTION
Wheeled floor jacks have been in use for many years to raise and lower automobiles. Large capacity models of heavy duty construction and weight have been the mainstay of professional car repair shops and service stations. Smaller, e.g. 1, 11/4, and 11/2 ton capacity floor jacks of lighter weight and construction have been marketed for some time for use by such repair shops for road service and general use. Due to their small size and light weight the general public has adapted them for home use as well and also as a spare jack to be used by the car owner and carried in the trunk of the car.
Examples of such conventional floor jacks are depicted in U.S. Pat. Nos. 4,018,421 and 4,131,263; advertised, for example, in Norco Form 842, 8-77, and in the Key Bar Model 2030 owner manual, both published by Norco Industries, Inc. of Gardena, Calif. Portable floor jacks of a similar nature have been shown on page 91 of Catalog No. 397B of the J. C. Whitney & Co., 1917 Archer Avenue, Chicago, Ill. Numerous other manufacturers and marketers, including those marketed under the Blackhawk trademark, are available.
Such wheeled floor or service jacks, while generally quite useful and popular, do suffer from some drawbacks. A major problem with such jacks results from the requirement that the jack move relative to the load (normally a car) while lifting it. While not a problem on hard surfaces, such as a concrete pad, this is a problem when one attempts to use the jack on a softer or uneven surface such as gravel, hot blacktop surfacing, dirt, snow or sand. Of course, when used as a trunk-carried jack, the jack must be useful on whatever surface the vehicle finds itself.
In typical use, in raising an automobile on such a soft surface, upon taking up some weight of the vehicle, the jack's wheels quickly bite into and sink so that the jack frame rests on the surface. But as it is necessary that the jack frame move relative to the vertical contracting saddle because of the basic design of such jacks, and the automobile is braked and preferably blocked so as not to roll (as per operating instructions of most jack manufacturers), then the frame must "snow plow" into the surface or else the saddle must "slip" relative to the vehicle. Of course, the latter can be harmful to the vehicle and/or the jack and could also cause serious injury to the user if an accidental dropping of the vehicle should occur. Also, when on blacktop surfaces, such as house driveways, the blacktop surface will be permanently "dented" or scarred.
While some have recognized the problem of wheel indenting in other types of jacks and provided a flat platform or base for the jack to spread the weight of the vehicle (e.g. U.S. Pat. Nos. 2,635,715; 2,594,270; 2,563,927; and 2,173,598) such have not been applied to wheeled floor jacks and indeed, if so applied, would result in a dangerous or unworkable jack.
While others have made low-slung lifting jacks for a special purpose (e.g. of car side only--e.g. Blackhawk roadside model 67393-1 ton) and eliminated the wheels, such stationary jacks are of limited use due to the low 1 ton capacity and because of the side only use, it makes it problematic to lift a car alongside a curb. Furthermore, such stationary jacks may be dangerous when used at other than their intended lifting points and for other applications.
SUMMARY OF THE PRESENT INVENTION
The present invention provides an accessory or attachment for a wheeled floor jack which allows the jack to be easily used on soft and semi-soft surfaces and allows the jack to be easily handled and stored when in the trunk. In accordance with the present invention, such an accessory comprises a guard, sized and shaped to encompass and includes means to loosely captivate the wheels of the jack and to provide a flat, hard surface for them to roll on. The guard defines an operating path within it to enable the jack to move horizontally, which path is long enough to enable the saddle of the jack to substantially move over its vertical path without horizontal displacement. That is, without slipping off its original contact point with the load.
This arrangement has the advantage of allowing the weight of the load to be spread about the bottom of the guard and prevents "snow plowing" or saddle slippage.
The invention, together with the advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawings, in the several figures of which, like reference numerals identify like elements.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a perspective view of an accessory or attachment constructed in accordance with the present invention.
FIG. 2 is a perspective view of the accessory of FIG. 1 in use with a jack.
FIG. 3 is a side view of the accessory of FIGS. 1 and 2 in use with a jack.
FIG. 4 is a sectional end-view of the accessory and jack.
FIG. 5 is an elevational view of the accessory of FIGS. 1-4 with a jack shown partially.
FIGS. 6 and 7 and views similar to FIG. 5 of the accessory of FIGS. 1-5 with the jack in a moved position.
FIG. 8 is a plan view of a stamping, which view is useful in explaining a preferred method of making the accessory of FIGS. 1-6.
FIG. 9 is a perspective view of a second embodiment of the invention, illustrating the attachment of the invention for a different style of wheeled floor jack.
DETAILED DESCRIPTION
Referring to FIGS. 1-4, there is depicted a guard 10 for a wheeled jack such as the jack 12 as shown in FIGS. 2, 3 and 4. The guard 10 has a generally rectangular base 14 in which the wheels 12W of the jack 12 rest when in use. As best seen in FIG. 1, arising from the base 14 are parallel upstanding sidewalls 18 and 20 which extend the length of the base. The sidewalls are spaced apart slightly more than the clearance between the wheels of the jack 12 so as to receive those wheels with easy clearance between the sidewalls 18 and 20 and them (FIG. 4). The guard 10 includes endwalls 22, 24 each of which has a curving bottom portion (such as 22C of FIG. 1) merging into the base 12 and curved at the curvature of the wheels of the jack. The marginal portion 26 of this wall 22 is bent down along the top of the wall 22 to form a handle at the front end of the guard 10. Longitudinal top marginal walls 28 and 30 project inside for short distances from the tops of the sidewalls 18 and 20.
These longitudinal marginal walls 28 and 30 are continuous from the front wall 22 to the back wall 24 except for two oppositely disposed cut-out sections 32 and 34. These sections are sized to receive the wheels 12W of the jack 12 as will be explained below. The wall 24 has end sections 24S and 24C which rise up and meet with the marginal top wall sections 28', 30' of the marginal walls 28, 30.
Formed rearward on the walls 28 and 30, near the opening 32, 34 are, respectively, upstanding tabs 28T and 30T which are formed from the walls 28 and 30 by cutting out and folding upward a finger-shaped portion of the walls. Spaced from these tabs on the walls 28 and 30 are secured, near the front wall 22, upstanding spring tabs which are respectively designated 28S and 30S. These spring tabs 28S and 30S are preferably made by securing short finger lengths of spring metal to the top of the walls 28 and 30 as by spot welding.
The pair of tabs 28T and 28S serve to releasably secure for storage the tubular jack handle front section 12H and the tabs 30S and 30T serve to similarly secure the jack handle rear section 12R as shown in FIG. 2. (These conventional sections 12H and 12R interlock to form the full jack handle).
These tubular handle sections are secured by placing one end in the spring tab 30S or 30T, resiliently bending it forward (by bending the section forward slightly) until the rear of the section can enter the opening of the rear tab 28T or 30T and then allowing the spring tab and section to return. The section 12H or 12F is then held by the tabs 28T and 28S or 30R and 30S. They can be easily removed by reversing the process.
The rear wall 24 of the guard 10 includes a turned-down portion 24P which serves to reinforce the rear wall and also may be used to secure a tensioning or biasing unit. This tensioning unit 50 is preferably a length of shock cord or strap secured at one end 52 in any convenient permanent manner to the end wall 24 and with a hook 51 at its free end. The unit 50 can, as shown in FIG. 2, have the hook 51 releasably attached to the axle 12A of the jack 12. (It may be attached at any other convenient position such as the brace 12B of the jack 12.) The tension strap 50 is attached to the guard 10 and jack 12 to eliminate unwanted movement with the guard (e.g. when transporting the jack in a vehicle) yet provide sufficient tension in its rearmost position to be in the ready position for use at all times. Also, enough elasticity is generated by the strap to allow the jack 12 to roll with the operating path and enables the jack 12 to move horizontally therealong.
As shown in FIGS. 2, 3, and 4, the sidewalls 18, 20 are sized so as to place the marginal walls 28, 30 over the wheels 12W of the jack 12 and prevent them from easily leaving the guard 10. Also, as can be seen from these figures, the base 14 extends longer than the length of the jack 12. As best seen in FIG. 3, this length allows the guard to serve as a non-moving shield for the moving jack frame and wheels 12W as the jack extends vertically and contacts and lifts a vehicle 60 or other load, e.g. between the position shown in phantom lines in FIG. 3 and that shown in solid lines in the same figure.
The jack 12 is placed in and releasably captivated by the guard 10 as shown in FIGS. 5, 6, and 7. That is, the jack 12 is aligned such that its frame is parallel to the opening of the guard 10 with the front wheels inserted into the openings 32, 34 (FIG. 5). Once in, the front wheels 12W are rolled forward and the hook 51 of the tensioning strap is looped over the axle 12A as shown in FIG. 6. The jack 12 is continuously moved forward (tensioning and stretching the strap 50) until the rear wheels can and do enter and, as shown in FIG. 2, the entire jack's wheels are rolled forward of the entry 32, 34 (FIG. 7).
Note that the wall segments 28', 30' are such as to prevent the exit of the wheels when the jack is in the rearmost position and that the tensioning strap 50 urges and holds the jack in the jack in that rearmost position. Thus only when the rear wheels are aligned exactly with the position of the opening 32, 34 can the jack be removed.
When used to raise a load, e.g. a vehicle 60, the jack 12 and guard 10 combination is placed under the vehicle on the ambient surface. The curvature on the bottom of the guard (front and rear) increases the ease of manuevering the guard and jack in combination under a vehicle on irregular or rough surfaces, thus preventing the "snow plowing" effect. The jack is positioned automatically in its rearmost position within the guard 10 by the tensioning strap 50 and the saddle raised until it contacts the desired position on the vehicle 60 (FIG. 3--dashed outline). As it is raised further, the load is transferred through the jack's wheels 12W to the guard 10 which serves to shield the wheels and jack from the surface below and to spread the weight over the base 14 to the ambient surface (such as the surface 61 of FIG. 3). This means that the surface can better take the load without giving. Further, as the saddle 12S is raised vertically further, the jack 12 can and does roll forward within the guard 10 along the path defined for it on the base 14 by the sidewalls, 18, 20. It does this easily as the surface 14 is smooth and hard, unlike some of the expected ambient surfaces 61. Even if the guard 10 is driven into the surface 61 somewhat, it will still provide a hard, flat, rolling surface for the wheels 12W.
Thus the jack can roll easily forward from the position 12' to the position 12 of FIG. 3. Note that the saddle 12S, 12' are vertically aligned. This means that the jack 12 is less likely to slip or damage the car as the saddle can remain in the same position on the load.
The guard 10 can be essentially made from a single sheet of metal. FIG. 8 illustrates a blank 100 cut from such a sheet. For example, for small capacity jacks (up to one and one-half tons) no. 14 gauge steel may be used. For larger capacity jacks or to provide even stronger construction, no. 12 gauge sheet steel can be used. The blank 100 is easily fabricated and assembled. With reference to FIG. 8, after stamping out the blank 100 portions 28, 30 (28' and 30') are bent at 90 degrees upward along the dashed lines, then the walls 18 and 20 are likewise bent up 90 degrees at the dashed lines. The end sections 26, 24P are bent over and then the walls 22 and 24 formed as shown in FIG. 1. The unit is then welded along the mating edges to provide a rigid and strong structure. The weld is preferably continued along all mating edges so as to provide a relatively water and mud-tight unit. The spring tab pieces 28 and 30S are then spot-welded in place.
If desired, a lighter gauge steel can be used for the end and sidewalls and this can be easily achieved by using such a blank as 100 and inserting a rectangular sheet over the base 14 and securing it to the base before the bending up of the sidewalls and endwalls.
The present invention may be adapted to various jack constructions. In FIG. 8, there is depicted a guard 10' for use in a wheeled jack of the type using casterwheels for its rear wheels. Here the back portion of the sidewalls 18', 20' is made to conform to and accommodate such wheels in a loose but close enough fit to hold them and yet define a path for the wheels and jack to travel. For some jack wheels, it may be desirable to modify them slightly so as to provide a smooth edge and prevent scratching or marking the base 14 along the edges of the wheels. However, if this becomes a problem, it can be solved by an insert or by simply using a thicker and stronger steel.
For purposes of illustration only and not for limitation, a particular prototype guard 10, substantially as depicted in FIG. 1, was constructed and tested for use with a model 2030 Keybar® floor service jack. This particular prototype had a width of about 71/4 inches, a length of about 26 inches and sidewalls about 2 and a half inches high and was made of 14 gauge sheet steel. This prototype was tested under various conditions and more than normal use and proved generally satisfactory, but was prone to a slight creasing along the sides of the front wheel path after extensive use. Such wear is considered acceptable for normal "emergency jack" use and, of course, can be avoided as mentioned above. The overlying marginal walls 28, 30 on this version were 7/8 inch in width and the cut-outs 32, 34 were each 21/2 inches long and located 11/4 inches from wall 24. The overall dimensions of the blank 100 were about 14 by 32 inches.
While two particular embodiments of the invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the invention in its broader aspects and, therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of the invention. For example, although shown and described as being made of sheet steel, other metals and construction techniques may be employed. In particular, the design of the unit of FIGS. 1-8 lends itself to aluminum extrusion construction. Also other units may be employed to retain the jack in the rearward position such as springs, rubber straps or mechanical detents. | An attachment or accessory to a wheeled floor jack of the type that rolls during use is disclosed. The accessory comprises a flat, elongated guard sized to receive and carry the wheels of the jack and to captivate them within it. The accessory provides a flat platform or base on which and within which the jack can roll and over which the weight lifted can be spread and serves to keep the wheels from the ambient surface. The attachment thus overcomes the problem encountered when using such jacks on a soft surface, such as snow, sand, dirt or asphalt, of having the wheels embed and the jack "snow plow," or slip. The attachment is designed to remain attached to the jack after insertion, but to easily receive the jack and be removed from it. The attachment also aids in handling the jack and limits or eliminates undesirable rolling, for example, when the jack is stored in the trunk of an automobile. | 8 |
FIELD OF THE INVENTION
[0001] The present disclosure generally relates to processes useful in making strong, soft, absorbent paper products. More particularly, the present disclosure relates to papermaking processes using belts formed from a resinous framework and a reinforcing structure having embedded sensors that provide process feedback that can provide a significant increase in the operating lifetime of the papermaking belt.
BACKGROUND OF THE INVENTION
[0002] Processes for the manufacturing of paper products for use in tissue, toweling and sanitary products generally involve the preparation of an aqueous slurry of paper fibers and then subsequently removing the water from the slurry while contemporaneously rearranging the fibers in the slurry to form a paper web. Various types of machinery can be employed to assist in the dewatering process.
[0003] The processes to manufacture these paper products use a paper slurry that is fed onto the top surface of a traveling endless belt that serves as the initial papermaking surface of the machine. These papermaking belts or fabrics carry various names depending on their intended use. Fourdrinier wires, also known as Fourdrinier belts, forming wires, or forming fabrics are used in the initial forming zone of the papermaking machine. Dryer fabrics carry the paper web through the drying operation of the papermaking machine.
[0004] One particular papermaking belt utilizes a foraminous woven member surrounded by a hardened photosensitive resin framework. The resin framework has a plurality of discrete, isolated, channels known as “deflection conduits” disposed therein. The process to manufacture a paper product can involve the steps of associating an embryonic web of papermaking fibers with the top surface of the papermaking belt, deflecting the paper fibers into the deflection conduits, and applying a vacuum or other fluid pressure differential to the web from the backside (machine-contacting side) of the papermaking belt. This process made it finally possible to create paper having certain desired preselected characteristics.
[0005] Although the aforementioned process produces suitable papermaking belts and results in superior formed paper products, it has been found that the papermaking manufacturing environment severely limits the lifetime of these papermaking belts. This could be attributed to the inability to measure certain key physical parameters of the papermaking belt during use. By way of example, the equipment used in the manufacture of paper products subjects the papermaking belt to extreme temperatures, bending moments, tensions, stress, strain, pH, wear, and the like. Each of these factors has been found to severely limit the life of the papermaking belts by causing micro-fractures to occur in the hardened resins that form the surface of the papermaking belt as well as fractures due to oxidation and decay of the resin itself. Without desiring to be bound by theory, resin loss is believed to be the primary cause of belt failure. This is particularly true of papermaking systems that incorporate the use of high temperature pre-dryers and Yankee drying drums. Additionally, the high pressures experienced by the papermaking belt in process nips (formed between pressure rolls) and vacuum slots, as well as process abrasion points (e.g., while traversing vacuum boxes and the like) and stresses introduced by misaligned process equipment have been linked to premature papermaking belt failures.
[0006] The significance of the difficulties experienced by users of these papermaking belts is exacerbatingly increased by the relatively high cost of the papermaking belts themselves. For example, manufacturing a foraminous woven element that is incorporated into these belts requires expensive textile processing operations, including the use of large and costly looms. Also, substantial quantities of relatively expensive filaments are incorporated into these foraminous woven elements. The cost of these papermaking belts is further increased when filaments having high heat resistance properties are used. These special filaments are generally necessary for papermaking belts that pass through various high temperature drying operations.
[0007] In addition to the cost of the belt itself, the decay and/or failure of a papermaking belt can also have serious implications on the efficiency of the papermaking process and the paper products so produced. A high frequency of paper machine belt failures can substantially affect the economies of a paper manufacturing business due to the loss of the use of the expensive papermaking machinery (that is, the machine “downtime”) during the time a replacement belt is being fitted on the papermaking machine.
[0008] Therefore, a need exists for an improved papermaking belt, a method of making a papermaking belt, and an ability to monitor the physical condition of a papermaking belt during use in the production of paper products that can eliminate the foregoing problems. In short, the ability to measure the physical condition of the papermaking belt made by the prior processes during use can provide for real-time in situ feedback into the papermaking process that can stimulate process changes necessary to produce quality paper products and simultaneously increase papermaking belt life.
SUMMARY OF THE INVENTION
[0009] The present disclosure provides for a process for adjusting a papermaking process for producing rolls of convolutely wound web material having a machine direction (MD) and a cross-machine direction (CD) coplanar and orthogonal thereto. The process improves the operating life of a papermaking belt used therefor. The process for adjusting the papermaking process comprising the steps of: providing a papermaking machine, said papermaking machine having at least one process set-point; providing a foraminous surface as a papermaking belt integral with said papermaking machine, said papermaking belt having a measuring device disposed integral thereto; depositing an aqueous dispersion of papermaking fibers upon a surface of said papermaking belt; dewatering said aqueous dispersion of papermaking fibers while disposed upon said surface of said papermaking belt; causing said papermaking belt to traverse past a receiver, said receiver being in wireless communicating engagement with said measuring device when said measuring device is proximate said receiver, said measuring device being capable of wirelessly transmitting information to said receiver, said information comprising data relating to a measurement of at least one in situ physical characteristic of said papermaking belt during said dewatering step; and, changing said process set-point according to said measurement of said physical characteristic of said papermaking belt.
[0010] The present disclosure also provides for adjusting a papermaking process for producing rolls of convolutely wound web material having a machine direction (MD) and a cross-machine direction (CD) coplanar and orthogonal thereto. The process improves the operating life of a papermaking belt used therefor. The process for adjusting the papermaking process comprising the steps of: providing a papermaking machine, said papermaking machine having at least one process set-point; providing a papermaking belt comprising a reinforcing structure, said reinforcing structure having at least one measuring device disposed integral thereto; providing said papermaking belt integral with said papermaking machine; depositing an aqueous dispersion of papermaking fibers upon a surface of said papermaking belt; dewatering said aqueous dispersion of papermaking fibers while disposed upon said surface of said papermaking belt; causing said papermaking belt to traverse past a receiver, said receiver being in wireless communicating engagement with said at least one measuring device when said measuring device is proximate said receiver, said at least one measuring device being capable of wirelessly transmitting information to said receiver, said information comprising data relating to a measurement of at least one in situ physical characteristic of said papermaking belt during said dewatering step; and, changing said process set-point according to said measurement of said physical characteristic of said papermaking belt.
[0011] The present disclosure further provides for a process for adjusting a papermaking process for producing rolls of convolutely wound web material having a machine direction (MD) and a cross-machine direction (CD) coplanar and orthogonal thereto. The process improves the operating life of a papermaking belt used therefor. The process for adjusting the papermaking process comprising the steps of: providing a papermaking machine, said papermaking machine having at least one process set-point; providing a papermaking belt comprising a reinforcing structure formed from a plurality of filaments, at least one of said filaments having at least one measuring device disposed therein; providing said papermaking belt integral with said papermaking machine; depositing an aqueous dispersion of papermaking fibers upon a surface of said papermaking belt; dewatering said aqueous dispersion of papermaking fibers while disposed upon said surface of said papermaking belt; causing said papermaking belt to traverse past a receiver, said receiver being in wireless communicating engagement with said at least one measuring device when said measuring device is proximate said receiver, said at least one measuring device being capable of wirelessly transmitting information to said receiver, said information comprising data relating to a measurement of at least one in situ physical characteristic of said papermaking belt during said dewatering step; and, changing said process set-point according to said measurement of said physical characteristic of said papermaking belt.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a schematic representation of one embodiment of a continuous papermaking machine useful in carrying out the process of this disclosure;
[0013] FIG. 2 is a plan view of a portion of an embodiment of the improved papermaking belt of the present disclosure;
[0014] FIG. 3 is an enlarged cross-sectional view of the portion of the improved papermaking belt shown in FIG. 2 taken along line 3 - 3 ;
[0015] FIG. 4 is an enlarged cross-sectional view of the portion of the improved papermaking belt shown in FIG. 2 taken along line 4 - 4 ;
[0016] FIG. 5 is an enlarged plan view of a portion of an exemplary woven multi-layer reinforcing structure suitable for use with the improved papermaking belt;
[0017] FIG. 6 is a schematic representation of the basic apparatus for making the papermaking belt of the present disclosure;
[0018] FIG. 7 is an enlarged schematic cross-sectional view of a portion of the casting surface of a process for making the papermaking belt of the present disclosure showing the working surface, barrier film, reinforcing structure, resin, and mask.
DETAILED DESCRIPTION
[0019] In papermaking, the term “machine direction” (MD) refers to that direction which is parallel to the flow of the paper web through the equipment. The “cross-machine direction” (CD) is perpendicular to the machine direction. The “Z-direction” refers to that direction that is orthogonal to both the MD and CD.
The Improved Papermaking Belt
[0020] In the representative papermaking machine illustrated in FIG. 1 , the papermaking belt 10 (or belt 10 ) of the present disclosure can take the form of an endless belt. In FIG. 1 , the papermaking belt 10 carries a paper web (“fiber web” or the like) in various stages of its formation and travels in the direction indicated by directional arrow B around the papermaking belt return rolls 19 a , 19 b , impression nip roll 20 , papermaking belt return rolls 19 c , 19 d , 19 e and 19 f , and emulsion distributing roll 21 . The loop the papermaking belt 10 travels around includes a means for applying a fluid pressure differential to the paper web, such as vacuum pickup shoe 24 a and multi-slot vacuum box 24 . In FIG. 1 , the papermaking belt can also travel around a pre-dryer such as blow-through dryer 26 , and pass between a nip formed by the impression nip roll 20 and a Yankee dryer drum 28 . Although an embodiment of the present disclosure is in the form of an endless belt, the present disclosure can be incorporated into numerous other forms.
[0021] The overall characteristics of the papermaking belt 10 of the present disclosure are shown in FIGS. 2-4 . The papermaking belt 10 of the present disclosure is generally comprised of two primary elements: a framework 32 and a reinforcing structure 33 . In one non-limiting example, framework 32 can be a hardened polymeric photosensitive resin. In one embodiment, the papermaking belt 10 is provided as an endless belt having two opposed surfaces which are referred to herein as the paper-contacting side 11 and a textured backside or simply, backside 12 . The backside 12 of the papermaking belt 10 contacts the machinery employed in the papermaking operation, such as vacuum pickup shoe 24 a and multi-slot vacuum box 24 . The framework 32 has a first surface 34 , a second surface 35 opposite the first surface 34 , and conduits 36 extending between the first surface 34 and the second surface 35 . The first surface 34 of the framework 32 contacts the fiber webs to be dewatered, and defines the paper-contacting side 11 of the belt. The conduits 36 extending between the first surface 34 and the second surface 35 channel water from the fiber web that rests on the first surface 34 to the second surface 35 and provides areas into which the fibers of the fiber web can be deflected into and rearranged. FIG. 2 shows that the network 32 a can comprise the solid portion of the framework 32 that surrounds the conduits 36 to define a net-like pattern.
[0022] As shown in FIG. 2 , the openings 42 of the conduits 36 can be arranged in a preselected pattern in the network 32 a . FIG. 2 shows that the first surface 34 of the framework 32 has a paper side network 34 a formed therein which surrounds and defines the openings 42 of the conduits 36 in the first surface 34 of the framework 32 . The second surface 35 of the framework 32 has a backside network 35 a that surrounds and defines the openings 43 of the conduits 36 in the second surface 35 of the framework 32 . FIGS. 3-4 provide that the reinforcing structure 33 of the papermaking belt 10 is at least partially surrounded by, enveloped, embedded, and/or encased within the framework 32 . More specifically, the reinforcing structure 33 is positioned between the first surface 34 of the framework 32 and at least a portion of the second surface 35 of the framework 32 . FIGS. 3 and 4 also show that the reinforcing structure 33 has a paper-facing side 51 and a machine-facing side 52 opposed thereto. As shown in FIG. 2 , the reinforcing structure 33 has interstices 39 and a reinforcing component 40 . The reinforcing component 40 comprises the portions of the reinforcing structure exclusive of the interstices 39 (that is, the solid portion of the reinforcing structure 33 ). A plurality of measurement device(s) 50 (also referred to herein as measuring device(s) 50 ) can be disposed within the framework 32 and can be incorporated into or upon the reinforcing structure 33 . Measurement devices 50 , their incorporation into a papermaking belt, and their usefulness will be discussed infra.
[0023] The reinforcing component 40 is generally comprised of a plurality of structural components 40 a . FIGS. 3-4 show that the second surface 35 of the framework 32 has a backside network 35 a with a plurality of passageways 37 . The passageways 37 allow air to enter between the backside surface 12 of the papermaking belt 10 and the surfaces of the vacuum dewatering equipment employed n the papermaking process (such as vacuum pickup shoe 24 a and vacuum box 24 ) when a vacuum is applied by the dewatering equipment to the backside 12 of the belt to deflect the fibers into the conduits 36 of the belt 10 .
[0024] The paper-contacting side 11 of the belt 10 shown in FIGS. 1-4 is the surface of the papermaking belt 10 which contacts the paper web which is to be dewatered and rearranged into the finished product. The paper-contacting side 11 of the belt 10 may also be referred to as the “embryonic web-contacting surface” of the belt 10 . As shown in FIGS. 2-4 , the paper-contacting side 11 of the belt 10 is generally formed entirely by the first surface 34 of the framework 32 .
[0025] As shown in FIG. 1 , the backside 32 is the surface which travels over and is generally in contact with the papermaking machinery employed in the papermaking process.
[0026] The reinforcing structure 33 is shown in FIGS. 2-4 and in isolation in FIG. 5 . The reinforcing structure 33 strengthens the resin framework 32 and has suitable projected open area to allow the vacuum dewatering machinery employed in the papermaking process to adequately perform its function of removing water from partially-formed webs of paper and to permit water removed from the paper web to pass through the papermaking belt 10 . The reinforcing structure 33 can comprise a woven element (also sometimes referred to herein as a woven “fabric”), a nonwoven element, a screen, a net (for instance, thermoplastic netting), a scrim, or a band or plate (made of metal or plastic or other suitable material) with a plurality of holes punched or drilled in it provided the reinforcing structure 33 adequately reinforces the framework 32 and has sufficient projected open area. Preferably, the reinforcing structure 33 comprises a foraminous woven element.
[0027] Generally, as shown in FIGS. 2-5 , the reinforcing structure 33 comprises a reinforcing component 40 and a plurality of interstices 39 . The reinforcing component 40 is the portion of the reinforcing structure 33 exclusive of the interstices 39 . In other words, the reinforcing component 40 is the solid portion of the reinforcing structure 33 . The reinforcing component 40 is comprised of one or more structural components 40 a . “Structural components” refers to the individual structural elements that comprise the reinforcing structure 33 .
[0028] The interstices 39 allow fluids (e.g., water removed from the paper web) to pass through the belt 10 . The interstices 39 may form any pattern in the reinforcing structure 33 . The pattern formed by the interstices 39 should be contrasted with the preselected pattern formed by the conduit openings.
[0029] As shown in FIGS. 3-4 , the reinforcing structure 33 has two sides. These are the paper-facing side (or “paper support side”) 51 that faces the fiber webs to be dewatered, and the machine-facing side (or “roller contact side”) generally designated 52 opposing the paper-facing side. As shown in FIGS. 3 and 4 , the reinforcing structure 33 is positioned between the first surface 34 of the framework 32 and at least a portion of the second surface 35 of the framework 32 .
[0030] The structural components 40 a of a woven reinforcing structure can comprise yarns, strands, filaments, or threads. It is also to be understood that the above terms (yarns, strands, etc.) could comprise not only monofilament elements, but also multifilament and/or multi-component (e.g., bi-component) elements. Many types of woven elements are suitable for use as a reinforcing structure 33 in the papermaking belt 10 of the present disclosure. Suitable woven elements include foraminous monolayer woven elements (having a single set of strands running in each direction and a plurality of openings therebetween) such as the reinforcing structure 33 shown in FIG. 5 .
[0031] The papermaking belt 10 comes under considerable stress in the machine direction due to the repeated travel of the belt 10 over the papermaking machinery in the machine direction and also due to the heat transferred to the belt by the drying mechanisms employed in the papermaking process. Such heat and stress can cause the papermaking belt to stretch. If the papermaking belt 10 stretches significantly, its ability to serve its intended function of carrying a paper web through the papermaking process can become diminished to the point of uselessness. If significant tension is applied to the papermaking belt 10 during manufacture of the papermaking belt 10 itself or during use of the papermaking belt 10 on a paper machine, mechanical failure can occur (i.e., the belt can rip or can be caused to sufficiently narrow (Poisson effect)).
[0032] To be suitable for use as a reinforcing structure, a multilayer woven element preferably has some type of structure that provides for reinforcement of the machine direction yarns 53 . In other words, the multilayer fabric should have increased fabric stability in the machine-direction.
[0033] As shown in FIGS. 2-5 , a preferred reinforcing structure 33 is a multilayer woven element that has a single layer yarn system with yarns which extend in a first direction and a multiple layer yarn system with yarns which extend in a second direction normal to the first direction. In the preferred reinforcing structure 33 , the first direction is the cross-machine direction. The yarns that extend in the first direction comprise the weft yarns 54 . The multiple layer yarn system extends in the machine direction. Fabrics having multiple machine direction warp yarns are preferred, however, because the additional strands run in the direction which is generally subject to the greatest stresses.
[0034] While the specific materials of construction of the warp yarns and weft yarns can vary, the material comprising the yarns should be such that the yarns will be capable of reinforcing the resinous framework and sustaining stresses as well as repeated heating and cooling without excessive stretching. Suitable materials from which the yarns can be constructed include polyesters, polyamides, high heat resistant materials such as KEVLAR™, NOMEX™, combinations thereof, and any other materials which are known for use in papermaking fabrics.
[0035] Any convenient cross-sectional dimensions (or size) of the yarns can be used as long as the flow of air and water through the conduits 36 is not significantly hampered during the paper web processing and as long as the integrity of the papermaking belt 10 maintained. The cross-sectional shapes of the yarns in the different layers and yarn systems can also vary between the layers and yarn systems.
[0036] The reinforcing structure 30 can have a first portion P 01 of the reinforcing component 40 that has a first opacity 0 1 , and a second portion P 02 of the reinforcing component 40 that has a second opacity 0 2 . The two opacities 0 1 and 0 2 can be related such that the second opacity 0 2 is less (that is, relatively less opaque) than the first opacity 0 1 . The first opacity 0 1 should be sufficient to substantially prevent the curing of a photosensitive resinous material, if such a material is used to form the framework 32 , when that photosensitive resinous material is in its uncured state and the first portion P 01 is positioned between the photosensitive resinous material and a source of actinic radiation.
[0037] The framework 32 can be formed by manipulating a mass of material, generally in liquid form, so that the material, when in solid form, at least partially surrounds the reinforcing structure 33 so that the reinforcing structure 33 is positioned between the first surface 34 and at least a portion of the second surface 35 of the framework 32 . The material can be manipulated so that the framework 32 has a plurality of conduits 36 or channels that extend between the first surface 34 and the second surface 35 of the framework 32 . The material can also be manipulated so that the first surface has a paper side network 34 a formed therein which surrounds and defines the openings of the conduits 36 in the first surface 34 of the framework 12 . In addition, the material can be manipulated so that the second surface 35 of the framework 32 has a backside network 35 a with passageways 37 , distinct from the conduits 36 .
[0038] The mass of material which is manipulated to form the framework 32 can be any suitable material, including thermoplastic resins and photosensitive resins, but the preferred material for use in forming the framework 32 of the present disclosure is a liquid photosensitive polymeric resin. Likewise, the material chosen can be manipulated in a wide variety of ways to form the desired framework 32 , including mechanical punching or drilling, curing the material by exposing it to various temperatures or energy sources, or by using a laser to cut conduits. The method of manipulating the material which will form the framework 32 , of course, can depend on the material chosen and the characteristics of the framework 32 desired to be formed from the mass of material. Preferably, the photosensitive resin is manipulated by controlling the exposure of the liquid photosensitive resin to light of an activating wavelength.
[0039] Since the reinforcing structure 33 is positioned between the first surface 34 and at least a portion of the second surface 35 of the framework 32 , the second surface 35 of the framework 32 can either, completely cover the reinforcing structure 33 , cover only a portion of the reinforcing structure 33 or, cover no portions of the reinforcing structure 33 and lie entirely within the interstices 39 of the reinforcing structure 33 .
[0040] The conduits 36 have a channel portion 41 which lies between the conduit openings 42 and 43 . These channel portions 41 are defined by the walls 44 of the conduits 36 . FIGS. 2-4 show that the holes or channels 41 formed by the conduits 36 extend through the entire thickness of the papermaking belt 10 . In addition, as shown in FIG. 2 , the conduits 36 are generally discrete. By “discrete”, it is meant that the conduits 36 form separate channels, which are separated from each other by the framework 32 . The conduits 36 are described as being “generally” discrete, however, because the conduits 36 may not be completely separated from each other along the second surface 35 of the framework 32 when passageways 37 are present in the backside network 35 a.
[0041] It is preferred that the passageways 37 and the irregularities 38 are distinct from the conduits 36 which pass through the framework 32 . By “distinct” from the conduits, it is meant that the passageways 37 and the irregularities 38 which comprise departures from the otherwise smooth and continuous backside network 35 a of the framework 32 are to be distinguished from the holes 41 formed by the conduits 36 . In other words, the holes 41 formed by the conduits 36 are not intended to be classified as passageways or surface texture irregularities.
[0042] Referring again to FIG. 1 , belt 10 carries an embryonic web 18 on the first surface. As shown, a portion of belt 10 passes over a single slot 24 d of a vacuum box 24 . In operation, a vacuum is applied from a vacuum source (not shown), which exerts pressure on the belts and the embryonic webs 18 in the direction of the arrows shown. The vacuum removes some of the water from the embryonic web 18 and deflects and rearranges the fibers of the embryonic web into the conduits 36 of the framework 32 .
[0043] The measurement devices 50 and an associated reading device 60 (also referred to herein as receiver 60 ) (the receiver 60 being efficaciously disposed about the papermaking process) are preferably configured to measure or monitor any physical characteristics of the papermaking belt 10 during the manufacture of paper products. The measurement devices 50 may also be configured to measure and monitor physical characteristics for controlling and monitoring the papermaking process. The characteristics that can be measured can include, e.g. belt temperature, belt deformation (e.g., tension, compression, bending moment, stress, and/or strain), belt and/or process pressure, belt acceleration (vibration), moisture, speed, pH, and the like. The measurement devices 50 may transmit measurement data when proximate to the receiver 60 , which may further communicate any measurement data to a control unit and/or a data acquisition system capable of processing and/or storing such measurement data. The measurement devices 50 may comprise a transmitter or a transceiver for communicating the measurement data wirelessly to a receiver 60 . The measurement devices 50 may be remotely-read untouchably by receiver 60 by means of electromagnetic radiation. Depending on the wavelength, the electromagnetic radiation used can include: radio waves, microwaves, infrared radiation, light, ultraviolet radiation, X-ray radiation, gamma radiation, and the like. Exemplary and suitable measurement devices can include those developed by the Wireless Identification and Sensing Platform of the University of Washington. Suitable reading devices 60 are the model S9028PCL UHF receiver manufactured by Laird Technologies.
[0044] Additionally, measurement devices 50 can be provided as microelectromechanical (MEMS), nanoelectromechanical (NEMS) systems, combinations thereof, and the like. Both MEMS and NEMS can be formed from graphene, at least in part, although other materials may be used alternatively as would be understood by those of skill in the art. As would be understood by one of skill in the art, graphene is a single atomic layer of carbon and is the strongest material known to man (where strength is not to be confused with hardness). It also has electrical properties superior to the silicon used to make the chips found in modern electronics. The combination of these properties can make graphene an ideal material for nanoelectromechanical systems, which are scaled-down versions of microelectromechanical systems used for sensing any physical characteristics and any physical phenomena including but not limited to temperature, vibration, and acceleration experienced by papermaking belt 10 during use.
[0045] Due to the continuous shrinking of electrical circuits, particularly those involved in creating and processing radio-frequency signals, they are harder to miniaturize. These ‘off-chip’ components can take up a lot of space and electrical power in comparison to the overall size of ultra-small systems. In addition, most of these radio wave-related components cannot be easily tuned in frequency, requiring multiple copies to ensure the range of frequencies used for wireless communication is covered. Graphene NEMS can address both problems in that they are compact and easily integrated with other types of electronics. Further, their frequency can be tuned over a wide range of frequencies because of the tremendous mechanical strength of graphene.
[0046] The measurement devices 50 may also comprise identification information, such as a code, an ID number, or the like. In addition to identification information, measurement devices 50 may comprise at least one other piece of information, which can include papermaking belt type number, manufacturer information, order information, date, order number or any other information that can be utilized during the installation, use, maintenance, manufacture, or quality control of the papermaking belt 10 or for ordering new papermaking belts 10 . The measurement devices 50 may comprise at least one memory wherein, in addition to the identification information, at least one piece of additional information (such as any physical characteristics of papermaking belt 10 measured during use) may be stored. The information stored in the memory can be changed during the process, during repair or washing of the belt 10 , as well as during storage thereof.
[0047] The data obtained from the measurement devices 50 may be utilized in controlling the papermaking process, choosing an appropriate belt for a papermaking process, clearing failures during the manufacture of products, as well as in choosing papermaking process operating parameters. Such an enhanced data acquisition system may thus significantly improve the efficiency and efficacy of the papermaking process as well as the papermaking belt 10 itself. Collected data can be forwarded from the data acquisition system for managing the production of, the use of, and/or the storage of the belts 10 as well as monitoring any necessary papermaking process conditions during the production of paper products that use papermaking belt 10 .
[0048] The measurement device 50 may comprise a tag responding to radio-frequency electromagnetic radiation. Identification distances and wave transmittivity, for instance, may be influenced by using different radio frequencies. The data acquisition system may further utilize tags responding to different frequencies of different sensors that can be used for measurement devices 50 (e.g., temperature, belt deformation, belt and/or process pressure, and the like). Additionally, the measurement devices 50 may comprise a tag, a transponder containing an antenna for receiving radio-frequency electromagnetic radiation as well as a microchip wherein the identification information is stored. Further, the measurement devices 50 may comprise a so-called Radio Frequency Identification (RFID) tag. The tag can be extremely small thereby making it easier to position within or upon the belt 10 . Such RFID tags are inexpensive, reliable, and highly available.
[0049] Measurement device 50 can be a passive RFID tag which comprises no power source of its own but the extremely low electric current required by its operation is induced by radio-frequency scanning received by the antenna contained within measurement device 50 and transmitted by the receiver 60 . By means of this induced current, the tag is able to transmit a response to an inquiry sent by the reading device. In other words, the reading device searches through (e.g., scans) the environment for a tag, and the tag transmits, for example, a measured physical characteristic of papermaking belt 10 , any ID code, and/or any other relevant and/or necessary information stored in the microchip (response) after the scanning has induced thereto the electric current necessary for the transmission. The RFID tag may be read at a radio frequency without visual communication and it may be read even through obstacles. In addition, exemplary RFID readers can read a plurality of measurement devices 50 , such as RFID tags, simultaneously.
[0050] The measurement devices 50 may comprise one or more portable electronic terminal devices suitable as a reading device 60 . The reading device 60 may be a data acquisition device, portable computer, palmtop computer, mobile telephone or another electronic device provided with the necessary means for remote-reading a tag. The reading device 60 may comprise a control unit included in the monitoring system.
[0051] By way of non-limiting example, measurement devices 50 can comprise thermocouples for measuring the temperature of the papermaking belt 10 . Alternatively, the measurement device 50 could comprise a strain gauge sensor that would be suitable for measuring the bending moment, tension, stress, and/or strain present within papermaking belt 10 . Yet still, measurement device 50 could be provided as a pressure sensor, a pH sensor, or even a wear (i.e., erosion) gauge.
[0052] If measurement device 50 is provided as a thermocouple, a thermocouple suitable for use as a measurement device 50 could be woven into the reinforcing structure 33 . Alternatively, the measurement device 50 could be disposed upon the reinforcing structure 33 and/or affixed to the reinforcing structure 33 by needlework or by way of adhesive. Further, measurement device 50 could be printed onto the reinforcing structure 33 using 3D-printing technology, for example. In any regard, it is preferred that measuring device 50 not have any adverse impact on the overall permeability of the papermaking belt 10 .
[0053] It is also believed that the measurement device 50 can be woven into the portion of the papermaking belt that is overlapped and re-woven to form a seam that makes papermaking belt 10 an endless loop. If it is chosen to apply the measurement device 50 only at this location on the papermaking belt 10 , one of skill in the art will understand that during use of the papermaking belt 10 , the result will be suitable measurements taken in a highly periodic fashion. For example, if a papermaking belt is 200 feet in overall length, and during manufacturing is operated at a linear speed of 2,000 feet/minute, the seam portion of papermaking belt 10 having measurement devices 50 disposed therein/thereon, can provide a measurement at any given point in the manufacturing process every 10 seconds.
[0054] Alternatively, it is believed that measurement device 50 can be provided as a portion of a bi-component filament material utilized to form reinforcing structure 33 . In other words, the measurement device 50 can be arranged as a filament that includes the measurement device 50 (and any associated electronics) as either the inner or outer portion of a coaxially formed bi-component filament or any other type of high performance cable. In this manner, one of skill in the art will recognize that any number of measurement devices 50 can be woven into and incorporated as part of reinforcing structure 33 at any location, or in any number of locations, within the confines of reinforcing structure 33 .
[0055] Yet still, if measurement device 50 is provided as a MEMS or NEMS (discussed supra), it is believed that one of skill in the art could incorporate such a MEMS or NEMS sensor(s) into the resin used to form the framework 32 . In this way a significant number of measurement devices 50 can be incorporated across the papermaking belt 10 in the CD, over its length in the MD, and combinations thereof. Measurement devices 50 can be disposed collinearly, sinusoidally, randomly, or in any fashion across the CD, MD, and combinations thereof. The use of such MEMS and/or NEMS sensors can significantly reduce any effects and/or impact of disposing a measurement device 50 into a papermaking belt 10 by reducing the amount of physical effort necessary to incorporate a measurement device 50 into the reinforcing structure 33 or the framework 32 as well as reduce the impact to the permeability of the papermaking belt 10 due to any portions of the measurement device 10 that may be disposed within a given conduit 36 .
Process for Making a Papermaking Belt
[0056] As indicated above, the papermaking belt 10 can take a variety of forms. While the method of construction of the papermaking belt 10 is immaterial so long as it has the characteristics required to manufacture paper products, certain methods have been discovered to be useful. One exemplary and non-limiting process for making the improved papermaking belt 10 of the present disclosure is described infra.
[0057] A preferred embodiment of an apparatus which can be used to construct a papermaking belt 10 of the present disclosure in the form of an endless belt is shown in schematic outline in FIG. 6 . In order to show an overall view of the entire apparatus for constructing a papermaking belt in accordance with the present disclosure, FIG. 6 was simplified to a certain extent with respect to some of the details of the process. The details of this apparatus, and particularly the manner in which the passageways 37 and the surface texture irregularities 38 are imparted to the backside network 35 a of the second surface 35 of the framework 32 are shown in the figures which follow. It should be noted at this point that the scale of certain elements shown may be somewhat exaggerated in the following drawing figures.
[0058] The overall process for making the improved papermaking belt 10 generally involves coating a reinforcing structure 33 having measurement devices 50 disposed therein or thereupon with a liquid photosensitive polymeric resin 70 when the reinforcing structure 33 is traveling over a forming unit or table 71 (or “casting surface”) 72 . Alternatively, a measurement device 50 provided as a MEMS or NEMS could be dispersed within the resin used to coat the reinforcing structure 33 .
[0059] As shown in FIG. 6 , the resin, or “the coating” 70 (with or without MEMS and/or NEMS) is applied to at least one (and preferably both) sides(s) of the reinforcing structure 33 (with or without a measuring device 50 disposed therein or thereupon) so the coating 70 substantially fills the void areas of the reinforcing structure 33 and forms a first surface 34 ′ and a second surface 35 ′. The coating 70 is distributed so that at least a portion of the second surface 35 ′ of the coating is positioned adjacent the casting surface 72 of the forming unit 71 . The coating 70 is also distributed so that the paper-facing side 51 of the reinforcing structure 33 is positioned between the first and second surfaces 34 ′ and 35 ′ of the coating 70 . In addition, as shown in FIG. 7 , the coating 70 is distributed so portions of the second surface 35 ′ of the coating are positioned between the opaque first portion P 01 of the reinforcing component 40 and the working surface 72 of the forming unit 71 . The portion of the coating which is positioned between the first surface 34 ′ of the coating and the paper-facing side 51 of the reinforcing structure 33 forms a resinous overburden t 0 ′. The thickness of the overburden t 0 ′ can be controlled to a preselected value.
[0060] The liquid photosensitive resin 70 is then exposed to a light having an activating wavelength (light which will cure the photosensitive liquid resin) from a light source 73 through a mask 74 which has opaque regions 74 a and transparent regions 74 b and through the reinforcing structure 33 . The portions of the resin which have been shielded or protected from light by the opaque regions 74 a of the mask 74 and by the first portion P 01 of the reinforcing structure 33 are not cured by the exposure to the light. The remaining portions of the resin (the unshielded portions, and those portions that the second portion P 02 of the reinforcing structure 33 permits the curing of) are cured. The uncured resin is then removed to leave conduits 36 which pass through the cured resin framework 32 .
[0061] For convenience, the stages in the overall process are broken down into a series of steps and examined in greater detail in the discussion which follows. It is to be understood, however, that the steps described below are intended only to provide an exemplary embodiment and to assist the reader in understanding a method of making the papermaking belt of the present disclosure.
First Step
[0062] The first step of the process of the present disclosure is providing a forming unit 71 with a working surface 72 . The forming unit 71 has working surface which is designated 72 . Preferably, the forming unit 71 is covered by a barrier film 76 which prevents the working surface 72 from being contaminated with resin. The barrier film 76 also facilitates the removal of the partially completed papermaking belt 10 ′ from the forming unit 71 . Generally, the barrier film 76 can be any flexible, smooth, planar material such as polypropylene, polyethylene, or polyester sheeting. Preferably, the barrier film 76 also either absorbs light of the activating wavelength, or is sufficiently transparent to transmit such light to the working surface 72 of the forming unit 71 , and the working surface 72 absorbs the light.
[0063] The barrier film 76 contacts the working surface 72 of forming unit 71 and is temporarily constrained against the working surface 72 . The barrier film 76 travels with the forming unit 71 as the forming unit 71 rotates. The barrier film 76 is eventually separated from the working surface 72 of the forming unit 71 . Preferably, the forming unit 71 is also provided with a means for insuring that barrier film 76 is maintained in close contact with its working surface 72 . Preferably, the barrier film 76 is held against the working surface 72 .
Second Step
[0064] The second step of the process of the present disclosure is providing a reinforcing structure 33 , for incorporation into the papermaking belt. FIG. 7 shows that the reinforcing structure 33 has a paper-facing side 51 , a machine-facing side 52 opposite the paper-facing side 51 , interstices 39 , and a reinforcing component 40 comprised of a plurality of structural components 40 a . A first portion P 01 of the reinforcing component 40 can have a first opacity 0 1 and a second portion P 02 of the reinforcing component 40 can have a second opacity 0 2 less than the first opacity 0 1 . The first opacity 0 1 is preferably sufficient to substantially prevent curing of the photosensitive resinous material when the photosensitive resinous material is in its uncured state and the first portion is positioned between the photosensitive resinous material and an actinic light source 73 . The second opacity 0 2 is preferably sufficient to permit curing of the photosensitive resinous material. Preferably, the reinforcing structure 33 is a woven, multilayer fabric.
[0065] If a measurement device 50 is provided, it could be woven into the reinforcing structure 33 . Alternatively, the measurement device 50 could be disposed upon the reinforcing structure 33 and/or affixed to the reinforcing structure 33 by needlework or by way of adhesive. Further, measurement device 50 could be printed onto the reinforcing structure 33 using 3D-printing technology, for example.
[0066] It is also believed that the measurement device 50 can be woven into the portion of the papermaking belt that is overlapped and re-woven to form a seam that makes papermaking belt 10 an endless loop. Alternatively, it is believed that measurement device 50 can be provided as a portion of a bi-component filament material utilized to form reinforcing structure 33 . In other words, the measurement device 50 can be arranged as a filament that includes the measurement device 50 (and any associated electronics) as either the inner or outer portion of a coaxially formed bi-component filament or any other type of high performance cable. In this manner, one of skill in the art will recognize that any number of measurement devices 50 can be woven into and incorporated as part of reinforcing structure 33 at any location, or in any number of locations, within the confines of reinforcing structure 33 .
[0067] Since the preferred papermaking belt 10 is in the form of an endless belt, the reinforcing structure 33 should also be an endless belt since the papermaking belt 10 is constructed around the reinforcing structure 33 . As illustrated in FIG. 6 , the reinforcing structure 33 which has been provided is arranged so that it travels in the direction indicated by directional arrow D 1 . It is to be understood that in the apparatus used to make the papermaking belt of the present disclosure, there are conventional guide rolls, return rolls, drive means, support rolls and the like which are not shown or identified with specificity in FIG. 6 .
Third Step
[0068] The third step in the process of the present disclosure is bringing at least a portion of the machine-facing side 52 of the reinforcing structure 33 into contact with the working surface 72 of the forming unit 71 (or more particularly in the case of the embodiment illustrated, traveling the reinforcing structure 33 over the working surface 72 of the forming unit 71 ). At least a portion of the machine-facing side 52 of the reinforcing structure 33 is brought into contact with the barrier film 76 so that the barrier film 76 is interposed between the reinforcing structure 33 and the forming unit 72 .
Fourth Step
[0069] The fourth step in the process is applying a coating of liquid photosensitive resin 70 to at least one side of the reinforcing structure 33 having the measurement devices 50 incorporated therein or disposed thereupon. Generally, the coating 70 is applied so that the coating 70 substantially fills the void areas 39 a of the reinforcing structure 33 (the void areas are defined below). The coating 70 is also applied so that it forms a first surface 34 ′ and a second surface 35 ′. The coating 70 is distributed so that at least a portion of the second surface 35 ′ of the coating 70 is positioned adjacent the working surface 72 of the forming unit 71 . The coating 70 is distributed so that the paper-facing side 51 of the reinforcing structure 33 is positioned between the first and second surfaces 34 ′ and 35 ′ of the coating 70 . The portion of the coating which is positioned between the first surface 34 ′ of the coating and the paper-facing side 51 of the reinforcing structure 33 forms a resinous overburden t 0 ′. The coating 70 is also distributed so that portions of the second surface 35 ′ of the coating 70 are positioned between the first portion P 01 of the reinforcing component 40 and the working surface 72 of the forming unit 71 .
[0070] Suitable photosensitive resins can be readily selected from the many available commercially. Resins which can be used are materials, usually polymers, which cure or cross-link under the influence of actinic radiation, usually ultraviolet (UV) light. Such a resin can be provided with measurement devices 50 provided as NEMS contained therein.
[0071] The application of resin 70 by the extrusion header 79 is employed in conjunction with the application of a second coating of liquid photosensitive resin 70 at a second stage by a nozzle 80 located adjacent to the place where the mask 74 is introduced into the system. The nozzle 80 applies the second coating of liquid photosensitive resin 70 to the paper-facing side 51 of the reinforcing structure 33 . It is necessary that liquid photosensitive resin 70 be evenly applied across the width of reinforcing structure 33 and that the requisite quantity of material be worked through interstices 39 to substantially fill the void areas 39 a of the reinforcing structure 33 .
[0072] It is also believed that the measurement device 50 can be placed into a portion of the resin that has been applied to the papermaking belt 10 . In other words, the measurement device 50 can be pushed into the resin forming the papermaking belt so that the resin can envelop the measurement device 50 prior to any curing process. In this way, the measurement device 50 (and any associated electronics) can be incorporated at any location, or in any number of locations, within the confines of papermaking belt 10 .
Fifth Step
[0073] The fifth step involves control of the thickness of the overburden t 0 ′ of the resin coating 70 to a preselected value. In the preferred embodiment of the belt making apparatus shown in the drawings, this step takes place at approximately the same time, i.e., simultaneously, with the second stage of applying a coating of liquid photosensitive resin to the reinforcing structure 33 . The preselected value of the thickness of the overburden corresponds to the thickness desired for the papermaking belt 10 and follows from the expected use of the papermaking belt 10 .
Sixth Step
[0074] The sixth step in the process of this disclosure can be considered as either a single step or as two separate steps which comprise: (1) providing a mask 74 having opaque 74 a and transparent regions 74 b in which the opaque regions 74 a together with the transparent regions 74 b define a preselected pattern in the mask; and (2) positioning the mask 74 between the coating of liquid photosensitive resin 70 and an actinic light source 73 so that the mask 74 is in contacting relation with the first surface 34 ′ of the coating of liquid photosensitive resin 70 . The purpose of the mask 74 is to protect or shield certain areas of the liquid photosensitive resin 70 from exposure to light from the actinic light source. It follows that if certain areas are shielded, it follows that any liquid photosensitive resin 70 in those areas that are not shielded will be exposed later to activating light and will be cured.
[0075] The mask 74 can be made from any suitable material which can be provided with opaque regions 74 a and transparent regions 74 b . A material in the nature of a flexible photographic film is suitable for use as a mask 74 . The flexible film can be polyester, polyethylene, or cellulosic or any other suitable material. The opaque regions 74 a should be opaque to light which will cure the photosensitive liquid resin. The opaque regions 74 a can be applied to mask 74 by any convenient means such as by a blue printing (or ozalid processes), or by photographic or gravure processes, flexographic processes, or rotary screen printing processes.
[0076] It should be understood that if one of skill in the art provides the measurement devices 50 as MEMS and/or NEMS, one could incorporate the measurement devices 50 into the treatments and/or solutions used to create the mask 74 . This could allow for the measurement devices 50 to be effectively transferred to the surface of the resulting papermaking belt 10 . In this case it would be preferred that such a measurement device 50 be transparent to the actinic radiation used in the curing process so not to interfere with the resin curing process.
Seventh Step
[0077] The seventh step of the process of this disclosure comprises curing the unshielded portions of liquid photosensitive resin in those regions left unprotected by the transparent regions 74 b of the mask 74 and curing those portions of the coating 70 that the second portion P 02 of the reinforcing structure 33 permits the curing of, and leaving the shielded portions and those portions of the coating positioned between the first portion P 01 of the reinforcing structure 33 and the working surface 72 of the forming unit 71 uncured by exposing the coating of liquid photosensitive resin 70 to light of an activating wavelength from the light source 73 through the mask 74 . When the barrier film 76 and the reinforcing structure 33 are still adjacent the forming unit 71 , the liquid photosensitive resin 70 is exposed to light of an activating wavelength which is supplied by an exposure lamp 73 .
[0078] The exposure lamp 73 , in general, is selected to provide illumination primarily within the wavelength which causes curing of the liquid photosensitive resin 70 . That wavelength is a characteristic of the liquid photosensitive resin 70 . Any suitable source of illumination, such as mercury arc, pulsed xenon, electrode-less, and fluorescent lamps, can be used. As described above, when the liquid photosensitive resin 70 is exposed to light of the appropriate wavelength, curing is induced in the exposed portions of the resin 70 . Curing is generally manifested by a solidification of the resin in the exposed areas. Conversely, the unexposed regions remain fluid. The intensity of the illumination and its duration depend upon the degree of curing required in the exposed areas.
[0079] In the preferred embodiment of the present disclosure, the angle of incidence of the light is collimated to better cure the photosensitive resin in the desired areas, and to obtain the desired angle of taper in the walls 44 of the finished papermaking belt 10 . Other means of controlling the direction and intensity of the curing radiation, include means which employ refractive devices (i.e., lenses), and reflective devices (i.e., mirrors). The preferred embodiment of the present disclosure employs a subtractive collimator (i.e., an angular distribution filter or a collimator which filters or blocks UV light rays in directions other than those desired). Any suitable device can be used as a subtractive collimator. A dark colored, preferably black, metal device formed in the shape of a series of channels through which light directed in the desired direction may pass is preferred. In the preferred embodiment of the present disclosure, the collimator is of such dimensions that it transmits light so the resin network, when cured, has a projected surface area of about 20-50% on the topside of the papermaking belt 10 and about 50-80% on the backside.
Eighth Step
[0080] The eighth step in the process in the present disclosure is removing substantially all of the uncured liquid photosensitive resin from the partially-formed composite belt 10 ′ to leave hardened resin framework 32 around at least a portion of the reinforcing structure 33 . In this step, the resin which has been shielded from exposure to light is removed from the partially-formed composite belt 10 ′ to provide the framework 32 with a plurality of conduits 36 in those regions which were shielded from the light rays by the opaque regions 74 a of the mask 74 and passageways 37 that provide surface texture irregularities 38 in the backside network 35 b of the framework 32 .
[0081] As shown in FIG. 25 , at a point in the vicinity of the mask guide roll 82 , the mask 74 and the barrier film 76 are physically separated from the partially-formed composite belt 10 ′. The composite of the reinforcing structure 33 and the partly cured resin 70 travels to the vicinity of the first resin removal shoe 83 a where a vacuum is to remove a substantial quantity of the uncured liquid photosensitive resin from the composite belt 10 ′.
[0082] As the composite belt 10 ′ travels farther, it is brought into the vicinity of resin wash shower 84 and resin wash station drain 85 at which point the composite belt 10 ′ is thoroughly washed with water or other suitable liquid to remove essentially all of the remaining uncured liquid photosensitive resin which is discharged from the system through resin wash station drain 85 .
[0083] The composite belt 10 ′ is then subjected to a second exposure of light of the activating wavelength by post cure UV light source 73 a . This second exposure, however, takes place when the composite belt 10 ′ is submerged in a bath 88 . The process continues until such time as the entire length of reinforcing structure 33 has been treated and converted into the papermaking belt 10 . At the second resin removal shoe 83 b , any residual wash liquid and uncured liquid resin is removed from the composite belt 10 ′ by the application of vacuum.
[0084] It is also believed that the measurement device 50 can be placed into any portion of the cured resin remaining on the papermaking belt 10 . In other words, a recess can be formed within the confines of the papermaking belt 10 and the measurement device 50 disposed therein. By way of non-limiting example only, a slot can be excised into the surface of the papermaking belt 10 and a measurement device 50 placed within the geometry of the slot so that the measurement device 50 (and any associated electronics) remains disposed below the surface of the papermaking belt 10 . Resin can then be applied and cured into the slot so formed thereby covering the measurement devices 50 .
The Papermaking Process
[0085] The papermaking process which utilizes the improved papermaking belt 10 of the present disclosure is described below, although it is contemplated that other processes may also be used to make the paper products described herein. Returning again to FIG. 1 , a simplified, schematic representation of one embodiment of a continuous papermaking machine useful in the practice of the papermaking process of the present disclosure is shown.
First Step
[0086] The first step in the practice of the papermaking process of the present disclosure is the providing of an aqueous dispersion of papermaking fibers 14 . The aqueous dispersion of papermaking fibers 14 is provided to a head box 13 . The aqueous dispersion of papermaking fibers 14 supplied by the head box 13 is delivered to a forming belt, such as the Fourdrinier wire 15 for carrying out the second step of the papermaking process. The Fourdrinier wire 15 is propelled in the direction indicated by directional arrow A by a conventional drive means which is not shown in FIG. 1 .
Second Step
[0087] The second step in the papermaking process is forming an embryonic web 18 of papermaking fibers on a foraminous surface from the aqueous dispersion 14 supplied in the first step. After the embryonic web 18 is formed, it travels with Fourdrinier wire 15 and is brought into the proximity of a second papermaking belt, the papermaking belt 10 of the present disclosure.
Third Step
[0088] The third step in the papermaking process is contacting (or associating) the embryonic web 18 with the paper-contacting side 11 of the papermaking belt 10 of the present disclosure. The purpose of this third step is to bring the embryonic web 18 into contact with the paper-contacting side of the papermaking belt 10 on which the embryonic web 18 , and the individual fibers therein, will be subsequently deflected, rearranged, and further dewatered. The Fourdrinier wire 15 brings the embryonic web 18 into contact with, and transfers the embryonic web 18 to the papermaking belt 10 of the present disclosure in the vicinity of vacuum pickup shoe 24 a.
[0089] As illustrated in FIG. 1 , the papermaking belt 10 of the present disclosure travels in the direction indicated by directional arrow B. The papermaking belt 10 passes around return rolls 19 a and 19 b , impression nip roll 20 , return rolls 19 c , 19 d , 19 e and 19 f , and emulsion distributing roll 21 .
[0090] It can be preferred that receivers 60 be staged around that portion of the papermaking process where the papermaking belt 10 of the present disclosure is used. In particular it could be advantageous to position the receiver(s) at locations that follow a heating process. For example, it may be advantageous to position receivers 60 after pre-dryer 26 . In this manner, the temperature of the papermaking belt 10 having measurement devices 50 disposed therein or thereupon in the form of thermocouples, can provide in situ feed-back of actual, real-time temperatures experienced by the papermaking belt 10 . By way of non-limiting example only, if a papermaking belt 10 , having thermocouples disposed therein, experiences a papermaking process temperature that is higher than required or allowed upon exiting pre-dryer 26 , the temperature of the pre-dryer 26 can be accordingly adjusted in order to reduce energy costs, produce paper products within specification, and preserve papermaking belt 10 life by reducing or even preventing the occurrence of micro-fractures or oxidation of the resin forming the papermaking belt 10 that causes the papermaking belt 10 to become brittle. All of these beneficial end results can result in lower manufacturing costs for paper products.
Fourth Step
[0091] The fourth step in the papermaking process involves applying a fluid pressure differential of a suitable fluid to the embryonic web 18 with a vacuum source to deflect at least a portion of the papermaking fibers in the embryonic web 18 into the conduits 36 of the papermaking belt 10 and to remove water from the embryonic web 18 through the conduits 36 to form an intermediate web 25 of papermaking fibers. The deflection also serves to rearrange the fibers in the embryonic web 18 into the desired structure.
[0092] Either at the time the fibers are deflected into the conduits 36 or after such deflection occurs, water is removed from the embryonic web 18 through the conduits 36 . Water removal occurs under the action of the fluid pressure differential. It is important, however, that there be essentially no water removal from the embryonic web 18 prior to the deflection of the fibers into the conduits 36 . As an aid in achieving this condition, at least those portions of the conduits 36 surrounded by the paper side network 34 a , are generally isolated from one another. This isolation, or compartmentalization, of conduits 36 is of importance to insure that the force causing the deflection, such as an applied vacuum, is applied relatively suddenly and in a sufficient amount to cause deflection of the fibers. This is to be contrasted with the situation in which the conduits 36 are not isolated. In this latter situation, vacuum will encroach from adjacent conduits 36 which will result in a gradual application of the vacuum and the removal of water without the accompanying deflection of the fibers.
Fifth Step
[0093] The fifth step is traveling the papermaking belt 10 and the embryonic web 18 over the vacuum source described in the fourth step. The belt 10 carries the embryonic web 18 on its paper-contacting side 11 over the vacuum source. At least a portion of the textured backside 12 of the belt 10 is generally in contact with the surface of the vacuum source as the belt 10 travels over the vacuum source. Following the application of the vacuum pressure and the traveling of the papermaking belt 10 and the embryonic web 18 over the vacuum source, the embryonic web 18 is in a state in which it has been subjected to a fluid pressure differential and deflected but not fully dewatered, thus it is now referred to as intermediate web 25 .
[0094] It could be advantageous to position the receiver(s) 60 at locations that follow such a vacuum process. For example, it may be advantageous to position receivers 60 after the vacuum source described supra. In this manner, the temperature of the papermaking belt 10 having measurement devices 50 disposed therein or thereupon in the form of a strain gauge can provide in situ feed-back of actual, real-time bending moment, stress, strain, erosion, and or combinations thereof experienced by the papermaking belt 10 . By way of non-limiting example only, if a papermaking belt 10 , having a strain gauge disposed therein, experiences a papermaking stress and/or strain that is higher than required or allowed upon exiting the vacuum source, the vacuum pressure applied by the vacuum source can be accordingly adjusted in order to reduce energy costs, produce paper products within specification, and preserve papermaking belt 10 life by reducing or even preventing the occurrence of micro-fractures or oxidation of the resin forming the papermaking belt 10 that causes the papermaking belt 10 to become brittle. All of these beneficial end results can result in lower manufacturing costs for paper products.
Sixth Step
[0095] The sixth step in the papermaking process is an optional step which comprises drying the intermediate web 25 to form a pre-dried web of papermaking fibers. Any convenient means conventionally known in the papermaking art can be used to dry the intermediate web 25 . For example, flow-through dryers, non-thermal, capillary dewatering devices, and Yankee dryers, alone and in combination, are satisfactory.
[0096] After leaving the vicinity of vacuum box 24 , the intermediate web 25 , which is associated with the papermaking belt 10 , passes around the return roll 19 a and travels in the direction indicated by directional arrow B. The intermediate web 25 then passes through optional pre-dryer 26 . This pre-dryer 26 can be a conventional flow-through dryer (hot air dryer) well known to those skilled in the art.
[0097] Receivers 60 can be staged around that portion of the papermaking process immediately after optional pre-dryer 26 . This can provide for in situ feed-back of actual, real-time temperatures experienced by the papermaking belt 10 during exposure to pre-dryer 26 by measurement devices 50 disposed therein or thereupon. If a papermaking belt 10 having, for example, thermocouples disposed therein, experiences a pre-dryer 26 process temperature that is higher than required or allowed, the temperature of the pre-dryer 26 can be accordingly adjusted in order to reduce or even prevent the occurrence of micro-fractures or oxidation of the resin forming the papermaking belt 10 that causes the papermaking belt 10 to become brittle.
Seventh Step
[0098] The seventh step in the papermaking process provides for impressing the paper side network 34 a of the papermaking belt 10 of the present disclosure into the pre-dried web by interposing the pre-dried web 27 between the papermaking belt 10 and an impression surface to form an imprinted web of papermaking fibers.
[0099] As illustrated in FIG. 1 when the pre-dried web 27 then passes through the nip formed between the impression nip roll 20 and the Yankee drier drum 28 . As the pre-dried web 27 passes through this nip, the network pattern formed by the paper side network 34 a on the paper-contacting side 11 of the papermaking belt 10 is impressed into pre-dried web 27 to form imprinted web 29 .
[0100] By way of non-limiting example, receivers 60 can preferably be staged around and/or proximate to those portions of the papermaking process where the papermaking belt 10 is subjected to a compressionary process. For example, a receiver could be staged at that portion of the papermaking process that follows contact of the papermaking belt 10 in the nip formed between impression nip roll 20 and the Yankee drier drum 28 . By way of example only, if a papermaking belt 10 , having pressure sensors disposed therein, experiences a higher or lower pressure than what is required, allowed, or the most efficacious to effect transfer of the paper web from one portion of the process to another, the appropriate nip pressure can be accordingly adjusted. Additionally, other critical parameters can be observed and understood in this nip. This can include the nip gap profile uniformity, nip loading profile uniformity, PLI loading uniformity, nip width/belt age profiles, and nip pressure uniformity.
[0101] Additionally, receivers 60 can also preferably be staged around those portions of the papermaking process where the papermaking belt 10 is subjected to other process forces. By way of non-limiting example, it can be seen in real-time if the papermaking belt 10 is experiencing any Poisson contraction effects resulting from thermal or mechanical induced over-stretching of the papermaking belt 10 . Additionally, equipment misalignments can be detected by monitoring the pressures observed by the papermaking belt 10 . Other critical parameters can be observed and understood. This can include the nip gap profile uniformity, nip loading profile uniformity, PLI loading uniformity, nip width/belt age profiles, and nip pressure uniformity. And measurement device 10 could be a chemical sensor to monitor water quality or running pH conditions in the papermaking process. Process anomalies can be detected by providing a measurement device 10 in the form of a plurality of strain gauges disposed within the papermaking belt 10 across the CD (e.g., the center and edges of papermaking belt 10 ) in order to understand, observe, and control the bending moment (i.e., bow deflection and/or skew) experienced by the papermaking belt 10 in process equipment (e.g., a Mt. Hope roll). Additionally, providing measurement device 10 as an accelerometer would be a unique method to understand, observe, and control speed changes between driven rolls of process equipment as well as adjust speeds for drive tuning.
[0102] These examples of the usefulness of the unique papermaking belt 10 can result in a reduction in energy costs, increase papermaking belt 10 life as well as increase the life of the contacted components by reducing wear on the contacting surfaces. It is reasonably believed, without being drawn to any particular theory, that papermaking belt 10 life can be at least doubled by reducing the detrimental effects experienced by the resin. All of these end results can result in lower manufacturing costs for paper products.
[0103] In any regard, the data measured by the measuring device 50 can be incorporated into a database that can be used to establish a papermaking belt 10 profile or a papermaking process profile. The collected data can be compared to an idealized or modeled set-point profile. Additionally, the data, and/or the profile can be looped back into the papermaking process. This can allow the adjustment of process temperatures, nip pressures, and the like in situ. Alternatively, the data and/or profile can be used to provide a historical perspective on papermaking belt 10 performance benchmarking over time as well as expected papermaking belt 10 life. Further, the data and/or profile can be used to manage process spikes such as web breakages, e-stops, and power outages that can cause manufacturing equipment to stop but not significantly reduce operating temperatures instantaneously.
Eighth Step
[0104] The eighth step in the papermaking process is drying the imprinted web 29 . The imprinted web 29 separates from the papermaking belt 10 of the present disclosure after the paper side network 34 a is impressed into the web to from imprinted web 29 . As the imprinted web 29 separates from the papermaking belt 10 of the present disclosure, it is adhered to the surface of Yankee dryer drum 28 where it is dried.
Ninth Step
[0105] The ninth step in the papermaking process is the foreshortening of the dried web (imprinted web 29 ). This ninth step is an optional, but highly preferred, step. Foreshortening refers to the reduction in length of a dry paper web which occurs when energy is applied to the dry web in such a way that the length of the web is reduced and the fibers in the web are rearranged with an accompanying disruption of fiber-fiber bonds. Foreshortening can be accomplished in any of several well-known ways. The most common, and preferred, method is creping.
[0106] In the creping operation, the dried web 29 is adhered to a surface and then removed from that surface with a doctor blade 30 . The surface to which the web is usually adhered also functions as a drying surface. Typically, this surface is the surface of a Yankee dryer drum 28 . The paper web 31 is then ready for use.
[0107] All publications, patent applications, and issued patents mentioned herein are hereby incorporated in their entirety by reference. Citation of any reference is not an admission regarding any determination as to its availability as prior art to the claimed invention.
[0108] The dimensions and/or values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension and/or value is intended to mean both the recited dimension and/or value and a functionally equivalent range surrounding that dimension and/or value. For example, a dimension disclosed as “40 mm” is intended to mean “about 40 mm”.
[0109] Every document cited herein, including any cross referenced or related patent or application, is hereby incorporated herein by reference in its entirety unless expressly excluded or otherwise limited. The citation of any document is not an admission that it is prior art with respect to any invention disclosed or claimed herein or that it alone, or in any combination with any other reference or references, teaches, suggests or discloses any such invention. Further, to the extent that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall govern.
[0110] While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention. | A method for adjusting a papermaking process for producing rolls of convolutely wound web material having a machine direction (MD) and a cross-machine direction (CD) coplanar and orthogonal thereto is disclosed. The process improves the operating life of a papermaking belt used therefor. | 3 |
BACKGROUND OF THE INVENTION
It has been known for many years that the pili of pilated pathogenic organisms play an important role in the pathogenicity of these organisms. It has been shown that these pili adhere to erythrocytes and similar cells whereby the bacteria are attached thereto. The mechanism by which pili adhere to erythrocytes and the like has also been long studied. It is believed that the adhering mechanism involves a particular protein which has an affinity for a particular group or groups on the surface of mammalian cells. Heretofore, it has been believed that the adhesion is a moiety which is part of the pilus rod protein.
SUMMARY OF THE INVENTION
A lectin which is derived from the pili of piliated organisms which is non-covalently bound to the pilus rod protein has been isolated. Lectins are proteins having a carbohydrate specific binding site (Ann. Rev. Plant Physiol. 27, 291 (1976)). They are subdefined by their origin, i.e., zoolectins or phytolectins. The subject matter of the present invention is a new sub-group, i.e., bactolectins (derived from bacteria). This lectin interacts mono-valently with sugar sites such as mannose sites on the surface of mammalian cells. The term monovalent in this context means that there is only one binding site for each lectin. The lectin is one of several minor protein components of the pili themselves. Among the organisms which possess such lectins may be named Escherichia Coli, in particular Type I E. Coli, Pseudomonas Aeruginosa, Bordatella Bronchiseptica, Moraxella Bovis, Salmonella Species, Haemophilus Influenzae, Moraxella Catarrhalis, Neisseria Gonorrhea, Neisseria Meningitidis, Klebsiella Pneumoniae, Bordatella Pertussis and Streptococcus Pneumonae. The lectins have a molecular weight of between about 25 to about 50 kilodaltons (Kd), suitably between 27 and 35 Kd. The binding site which is responsible for adhesion to the aforesaid sugar moiety on the mammalian cells is, for certain lectins, deactivable by aqueous papain in the presence of urea provided that the urea concentration is at least 4M. Where the urea concentration is less than 4M, very little denaturation takes place and even at concentrations of 8M urea, there is no denactivation in the absence of papain.
In order to produce the lectins of the present invention substantially pure pili are produced. These pili are then digested with a detergent, suitably sodium dodecyl sulfate or sarkorsinate at a concentration of between about 2 to about 5 wt. % and a pH of about 7 to about 9. The pili are then digested. It is preferred to carry out the digestion in two stages. In the first stage, it is carried out at between about 20° to about 40° C. after which the undissolved material is removed, the aqueous residue discarded and the said undissolved material redissolved in a similar solution and redigested at a higher temperature, suitably between about 80 and 100° C. The remaining undissolved material is again removed, suitably by centrifuguation, preferably at at least 10,000 g., suitably up to about 100,000 g. The aqueous material is again preserved. The proteinaceous material in these aqueous solutions is then precipitated. Suitably, the precipitant is a 10-20 vol/vol of a water soluble organic solvent such as an alkyl ketone, suitably acetone; a carboxylic acid such as acetic acid; or a tertiary amine such as trialkylamine. The precipitate is then separated, washes with suitable solvent, and redissolved in the aforesaid detergent solution but at a lower concentration, suitably between about 0.5 and 2 wt. % (SDS).
The proteins in this solution are then resolved by well known procedures such as gel filtration chromatography or acrylamide gel electrophoresis and the desired lectin, having a molecular weight as stated hereinabove, is isolated. The lectins constitute approximately 1% by weight of the protein content of the pili. It has been found that the lectins derived from E. coli Type I pili and from Salmonella Type I pili are D-mannose specific.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. I is a photograph of an SDS acrylamide gel chromatogram of the depolymerized pili of Table 1.
FIG. II is a photograph of an SDS acrylamide gel chromatogram of products of Example V.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In preparing the lectins of the present invention it is desirable to start with substantially pure pili, free from other contaminants. In the preferred mode, piliated bacteria are grown on rich solid medium and are suspended in 0.15M aqueous saline prior to blending, suitably at about 10,000 rpm for from about 1 to about 5 minutes. The supernatant of the centrifugation is preserved and separated from the precipitated cells. The pili in the supernate are aggregated by addition of a suitable salt, for example, 0.1M magnesium chloride, and are purified by alternating cycles of crystallization and solubilization to remove soluble and particulate debris respectively.
The piliated organisms can be grown in a fairly wide temperature range, for example, between about 20° and about 40° C. While magnesium chloride is preferred as the precipitating agent, calcium chloride, sodium chloride, potassium chloride or ammonium sulfate of at least 5% saturation or more may be utilized.
It has been found that the pili maintain their integrity under mild detergent conditions. Thus, the pili suspended in an alkaline buffer, suitably from between 7 to about 9, with between 2 to 5% of detergent, suitably sodium dodecyl sulfate or sarkosinate. Dithiothreitol (up to 50 mM, preferably 5 to 10 mM) may be added to aid solubilization. The suspended pili are mixed in the solution at a temperature of between about 20° to about 37° to ensure dispersal of all the clumps of material. The pili are then sedimented by centrifugation, suitably at about 10,000 g or greater. This procedure ensures removal of undesired soluble contaminants.
Occurrence of Pilus-Associated Proteins
E. Coli Type I pili were purified from 20 different strains (numbers 1-19 courtesy of H. J. Cho). Concentrations range from 0.36 mg/ml to 2.46 mg/ml. Pili were depolymerized (pH 2/100°), run on SDS-PAGE and silver stained. Order of strains is as given in Table 1. The position of the 28 Kd band is indicated in FIG. I. Lane 21 contains MW standards.
TABLE 1______________________________________Hemagglutinating Activities within the Type I Family HA EndpointStrain/ Conc. Sero-Clone (ug/ml) Type Isolate Source______________________________________(1) SP9/001 24 II Porcine enterotoxigenic(2) SP13/001 2 II "(3) SP14/001 36 II "(4) SP16/001 25 II "(5) H10401/001 2 ND(a) Human enterotoxigenic(6) H10401/003 25 ND "(7) H10407 2 IV "(8) H13634/001 3 IV Human enteroinvasive(9) B44/001 36 II Bovine enterotoxigenic(10) Br11/001 13 X Human pyelonephritic(11) Br0111/001 3 II "(12) AW405 >230 ND Lab. (J. Adler)(13) C9/001 91 VIII Human cystitic(14) PS/001 49 II Porcine enterotoxigenic(15) 27052/001 13 IX Human ABU.sup.(b)(16) 1676/003 36 I Porcine enterotoxigenic(17) 1459/003 3 XIII Bovine enterotoxigenic(18) 190/103 25 II Porcine enterotoxigenic(19) SP27/005 25 II "(20) BAM 2 I Lab. (E.Kellenberger)______________________________________
The aggregated pili from the centrifugation are again resuspended in the detergent at a concentration exceeding 1 mg/ml. It is preferred that a concentration of between 5 to about 10 mg/ml is attained. The solution is then heated to a temperature of at least about 80°/C. up to 100° C. for at least 2 minutes, a 5 minute digestion at 100° C. being preferred. This procedure removes all noncovalently bound proteinaceous material from the pili, leaving pure pilin rods which are then removed by centrifugation at least 10,000 g, suitably up to 100,000 g. In order to avoid precipitation of the detergent, it is preferable to keep the temperature in the range of about 10° to about 20° C. The pellet is then washed, suitably with water or a low strength buffer and the foregoing digestion step is repeated if desired, to obtain purified pilin rods. It is preferable to add protease inhibitors, such as diisopropyl fluorophosphate, phenylmethyl sulphonyl fluoride, etc., to the supernatant, if it is to be stored for more than about 12 hours. The preferred storage temperature is between about 4°.
The last small fragments of rods and rod aggregates may be removed from the supernatant, suitably by filtration (pore size 0.45 um or less) at a temperature suitably between about 20° to about 25° C. to prevent precipitation of the detergent.
The soluble proteins are then precipitated with organic solvents. These solvents are water soluble organic solvents such as lower (1 to 5 atoms) alkyl ketones suitably acetone, lower carboxylic acids suitably acetic acid or tertiary alkyl amine compounds, suitably trimethyl or triethyl amine or mixed solvents such as chloroform/methanol. The thus formed precipitate of minor non-covalently linked proteins is collected, washed in the precipitating solvent, and redissolved in a more dilute solution of the foregoing detergent, suitably at a concentration of between about 0.5 to about 2 wt. %. It is preferred that solution of the proteins be assisted by brief heating suitably from about 2 to about 5 minutes and between 80° to about 100° C.
Resolution of the thus resolved proteins may be carried out by any suitable method. It has been found that resolution may be achieved by chromatography on gel filtration media of fractionation range between about 10,000 to about 100,000 d (media such as Sephadex G75, G100, Biogel P100 or P150, Ultragel ACA54, ACA44 or equivalent media may be employed). Chromatography is carried out using low concentration alkaline SDS/DTT buffer (0.05 to about 0.5 wt. % SDS). Again, it is preferred that the temperature be high enough (i.e., about 20° to about 25° C.) to prevent precipitation of the detergent. Alternatively, the proteins may be resolved by preparative scale SDS polyacrylamide gel electrophoresis wherein the protein bands are visualized, cut out, and the protein eluted from the gel slices. The band visualization may also be obtained by staining, for example with Coomassie Blue in methanol acetic acid or by SDS precipitation with salts such as sodium acetate or potassium chloride. In this procedure, soaking the gel in between 0.25M and 1.0 M potassium chloride is preferred. After brief soaking in water to remove the staining solvents or salts, the protein is removed from the slice by electro elution in an SDS buffer of ionic strength about 0.1M or maceration and diffusion into a solution of SDS (1 to 10% wt/vol).
Finally, the precipitated proteins may also be resolved by HPLC by previously suspending them in a suitable ion pairing type solvent (0.5 to 0.05% trifluoroacetic acid is preferred). Separation is carried out by reverse phase chromatography on a suitable hydrophobic interaction column and by elution with an organic solvent gradient in water, for example, 0 to 100% acetonitrile.
The fragments collected in the buffered detergents may be dialyzed at low concentration salt solution (sodium chloride, potassium chloride or potassium phosphate are especially suitable at 0.05 to 0.15M), followed by dialysis to remove salts, dyes and higher amounts of SDS resulting from the purification of these proteins. Those proteins having a molecular weight between 25 and 50 Kd represent the desired fraction, which is preserved.
Characterization of the Adhesion Protein
It is an interesting observation that while crystalline (i.e., aggregated) pili cause hemagglutionation of erythrocytes, erythrocyte ghosts and other vertibrate host cells, single rod pili do not cause hemagglutination. Nevertheless, when erythrocytes are exposed to single rod pili (i.e., pilin rod associated with its minor proteins) or when polystyrene latex beads coated with a sugar, such as D-mannose are exposed to single pilus rods and then examined either by exposure to electron microscope or in a high powered optical microscope, it is observed that the single rod pili will adhere at a location proximal to one end thereof to the aforesaid erythrocyte ghosts or the mannose treated polystyrene beads. Interestingly however, it has been observed that when these adhered single rod pili are exposed to anti-pilus rod antiserum containing antibodies to the pilus rod itself, hemagglutination will immediately occur since a cross-linking between the individually adhered pilus rods will take place.
Further evidence for the binding property of the lectins of the present invention comes from observations of a mutant strain of E. Coli Type I pili (Strain K12-AW405) (Collection of the Department of Microbiology, University of Pittsburgh, Charles C, Brinton, Source--J. Adler) which when grown at 37° C. or above was found to produce pili which had no detectable hemagglutinating activity with respect to erythrocyte ghosts. When subjected to the detergent digestion procedures of the present invention, it was found that this strain, while having minor proteins, was lacking a protein in the 25 to 50 Kd range.
It has been found that the adhesion quality of certain single rod pili can be deactivated by the action of papain in urea. Unless the urea concentration exceeds 4M, only negligible deactivation will occur. On the other hand, no deactivation will occur if papain is absent up to a concentration of 8M urea. None of the minor proteins isolated in the foregoing detergent digestion will cause hemagglutination. Furthermore, none of these proteins except for the lectin will adhere to erythrocyte ghosts. Similarly, the adhesive interaction between the native pilus associated lectin and the erythrocytes can be prevented by treatment of the un-adhered lectins with antilectin antibody.
The thus produced lectins have many uses due to their carbohydrate specificity. They can be bound to such substrates as polystyrene gel by conventional procedures such as treatment with cyanogen bromide, whereby they can serve as affinity substrates for the purification of specific carbohydrates from complex mixtures, for example, the E. Coli and Salmonella Type I pili, being mannose specific may be utilized for the isolation of mannose from mixtures containing same. Similarly, monoclonal antibodies to the lectins may be prepared which in turn are used to generate anti-idiotype antibodies, which in turn can be used as anti-idiotype vaccines in order to generate specific idio types to the tip adhesion proteins within the system to which they are administered. Furthermore, it is possible to attach markers to the lectins which lectins are then utilized as biosensors for the detection and assay of predetermined carbohydrates such as mannose.
The procedures of the present invention which involve mild detergent digestion of the pili make possible the removal from single rod pili of lipopolysaccharides associated therewith. This is an important development in the manufacture of whole pilus vaccines as the lipopolysaccharides cause antigenic reactions without immunizing benefit.
The procedures also make possible, by the more vigorous digestion with detergent, the production of pure pilin rods which are useful as a diagnostic tools for the characterization of pilus families by procedures such as the ELISA assay.
EXAMPLE I
Purification of Pili
E. Coli Type I piliated bacteria (ATCC 67053, Strain Bam; Collection of Department of Microbiology, University of Pittsburgh, Charles C. Brinton--Source E. Kellenberger, Geneva, Switzerland (1954)) are grown on rich solid medium in the conventional manner at a temperature within the range of 22° to 37° C. The bacterial growth is then suspended in aqueous sodium chloride (0.15M) and blended (10,000 rpm, 2 minutes). The product is then centrifuged at 10,000 g, the residual debris removed and the solubilized pili aggregated by the addition of aqueous magnesium chloride (0.1M). The aggregated pili are then precipitated by similar centrifugation and the supernatant discarded. The foregoing solution/precipitation cycle is repeated at least three (3) times to obtain substantially pure E. Coli Type I pili. Pili (100 mg) are suspended in SDS (40 ml, 4% w/w), dithiothreitol (10 mm), pH 8 and agitated for 15 min at 25° C., followed by centrifugation at 10,000 g. The residue comprises pili substantially free of lipopolysaccharide contaminants.
EXAMPLE II
In accordance with the above procedure but in place of utilizing E. Coli, there may be utilized P. Aeruginosa, B. Bronchiseptica, M. Bovis, Salmonella Species, H. Influenzae, M. Catarrhalis, N. Gonorrhea, N. Meningitidis K. Pneumoniae, B. Pertussis or S. Pneumoneae.
EXAMPLE III
E. Coli Type I pili 200 mg. were suspended in an aqueous solution of sodium dodecyl sulfate (4%, 10 ml) containing 10 mM dithiothreitol (DTT), and 10 mM tris at pH 8 and boiled for 5 minutes. The mixture was cooled to between 20° and 25° C. and sedimented by centrifugation at 100,000 g for 1 hour to yield the SDS aggregated pilin rods as the precipitate.
The supernatant contains the three minor proteins having molecular weights of approximately 28 Kd, 16.5 Kd and 14.5 Kd as shown by SDS polyacrylamide electrophoresis.
EXAMPLE IV
Separation of Minor Proteins
The aqueous solution containing the proteins from the previous Example was treated with acetone (100 ml). Whereby the proteins were precipitated, the mixture centrifuged at 10,000 g. for 15 minutes, the supernate discarded and the precipitate resuspended in SDS solution (1%, 10 ml) containing 10 mM tris, 1 mM dithiothreitol at pH 8. The mixture was loaded onto a Sephadex G75 column (1.5 by 110 cm) and the proteins eluted with a similar buffer of SDS (0.1%). Flow rate was 8 ml/hr. and 1 ml fractions were collected. Gel chromatography (FIG. 2) showed that the 28 Kd protein was located principally in fractions 3 thru 8, starting at the void volume.
The fractions were pooled and acetone precipitated as above.
EXAMPLE V
In accordance with the above procedure but in place of utilizing E. Coli, there may be utilized P. Aeruginosa, B. Bronchiseptica, M. Bovis, Salmonella Species, H. Influenzae, M. Catarrhalis, N. Gonorrhea, N. Meningitidis, K. Pneumoniae, B. Pertussis or S. Pneumoneae to yield a similar lectin.
TABLE 2______________________________________Amino Acid Analysis of Pilus Associated ProteinsObtained in the Foregoing Experiments 37518 BAM Rod Rod Subunit Subunit 37518 37518 BAMAmino 20.5 Kd 17 Kd 14 Kd 33 Kd 28 KdAcid # RES # RES # RES # RES # RES______________________________________ASP 24 20 18 41 32THR 28 20 14 25 26SER 18 10 8 23 24GLU 13 13 11 25 17PRO 11 2 7 21 16GLY 14 17 17 ND NDALA 34 34 18 25 25CYS (1/2) 3 2 ND ND NDVAL 14 13 7 30 29MET 1 0 0 2 0ILE 7 4 5 13 12LEU 12 10 12 18 17TYR 3 2 3 13 15PHE 7 8 4 14 9HIS 1 2 1 2 2LYS 9 3 5 13 6ARG 4 3 4 14 8TRP ND 0 ND ND NDTOTAL 203 163 134 279 238MW 20540 17000 13600 33200 28000______________________________________
Amino acid analysis data of pilus-associated proteins from strain Salmonella Newport #37518 and E. Coli Type I strain BAM.
EXAMPLE VI
Papain Inactivation of Pili
Pure pilus rods (crystalline) pili were resuspended to 0.5 mg/ml in 50 mM NaCl, 10 mM tris, 10 mM cysteine-HCl, 5 mM EDTA, pH 7.4 with various concentrations of urea. A freshly prepared solution of papain in water was added to half of each pili-urea suspension to a final pili:papain ratio of 25:1 (wt:wt). The remaining half received no papain. The pili (0.5 ml) in urea with or without papain were incubated at 37° for 1 hour, then placed in individual dialysis sacs and dialyzed extensively against distilled water. The evidence of proteolysis was judged by SDS-PAGE of depolymerized and undepolymerized papain-treated pili.
Papain treatment had no effect on any protein associated with whole pili unless urea was present in excess of 4M. In these samples, only the 28 Kd band, is lost. No degradation of any band occurs in 8M urea in the absence of Papain.
The relative adhesion activity of papain/urea-treated pili was determined by passive hemagglutination (HA). Dialyzed soluble pili were two-fold serially diluted in phosphate buffered 50 mM NaCl containing 4% sorbitol. An equal volume of 2% guinea pig blood was added, the mixture incubated 30 minutes, then added to an equal volume of 1:100 anti-whole pilus serum. Relative HA strength is expressed as the titration endpoints. Treating pili with urea at 0 to 8M in concentration in the absence of papain had little effect on HA activity. The activity of pili incubated with papain was unaffected at concentrations of urea less than 4M, but decreased to negligible levels at urea concentrations of 4M or above when the enzyme was present. Though no attempt was made to eliminate residual papain activity in the HA assay, control experiments showed that results from assays to which active papain was deliberately added were identical to those without added enzyme.
EXAMPLE VII
Coupling of 28 Kd Lectin to Solid Carrier Beads for Use as Mannose Receptor Specific Probe
One Hundred (100) mg. of lectin derived from E. Coli Type I (strain Bam) prepared in accordance with Example IV is mixed with 10 ml. of CNBr Sepharose Gel (Pharmacia.) in a mixture of 0.1M NaHCO 3 and 0.5M NaCl at pH 8.3. The mixture is agitated gently for 2 hours at ambient temperature and the unreacted CNBr groups blocked with 1M ethanolamine for 2 hours at ambient temperature. The excess unbound protein is washed away with coupling buffer followed by 0.1M acetate buffer (pH 4) containing 0.5M NaCl. After washing again with coupling buffer to remove excess blocking agent, the lectin conjugated Sepharose is utilizable as a probe for materials containing mannose specific receptor sites. | A lectin derived from the pili of piliated organisms, said lectin being non-covalently bindable to the pilus rod protein of said pili and separable therefrom by the action of aqueous sodium dodecyl sulfate, possessing a single binding site for binding to mammalian erythrocyte ghosts. | 8 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a divisional application of U.S. patent application Ser. No. 08/724,977, filed Oct. 3, 1996, which claims the benefit of U.S. Provisional Application No. 60/006013 filed Oct. 23, 1995, and which is a continuation-in-part of, and claims the benefit of, U.S. patent application Ser. No. 08/320,540 filed Oct. 12, 1994, and U.S. patent application Ser. No. 08/686,998 filed on Jul. 24, 1996, now U.S. Pat. No. 5,661,760.
FIELD OF THE INVENTION
The present invention relates to apparatus and methods for storing, detecting, and synchronously detecting servo information stored on disk drive media, and in particular to apparatus and methods useful within partial response, maximum likelihood detection channels and magnetic disk media.
BACKGROUND OF THE INVENTION
By reading servo information recorded within data tracks on a disk surface, a disk drive head positioner servo system is able to estimate data transducer head position. The recorded servo information typically includes track (i.e. cylinder and head) addresses and servo bursts. Each circumferential data track on a disk surface has a unique track address, which is recorded in servo sectors embedded in the track, and servo burst patterns frequently repeat every two or more tracks. When a disk drive is seeking to a radial track location, the track addresses are used as coarse positioning information to approximately estimate the position of the read head and the servo bursts are used as fine positioning information to position the head precisely on the desired radial location.
At seek time while reading track addresses, the head may be positioned between two adjacent tracks. In this situation, the head may receive a superposition of signals from both tracks. One solution to this ambiguity is to encode the track addresses into Gray-coded addresses so that the encoded addresses of any two adjacent tracks differ from each other by only in a single bit position. With this solution, when the head is reading between two tracks, the ambiguity after decoding the address is one track, and an error of one track can be resolved during seek settle time, by reference to the servo burst or fine-position pattern.
In accordance with one known technique, each data track is divided into plural sectors. Each sector includes a header section, followed by a data section. The header section may typically include a DC erase field, a preamble field, a header synchronization character, a track address field (coarse servo information) and a servo burst field (fine servo information). The data section may typically include another preamble field, a data synchronization character, a block of user data, and error correction bytes. In this example, the header section is recorded at the same data rate as the data section, and synchronous peak detection through a single read channel structure in the disk drive is employed to read the information in both the header section and the data section. An example of this approach is found in commonly assigned U.S. Pat. No. 5,036,408 to Leis et al., entitled: “High Efficiency Disk Format and Synchronization System”, the disclosure thereof being incorporated herein by reference.
Another known technique is to employ radial zones or bands of concentric data tracks, each zone having a data transfer rate associated with disk radius of the zone. In this example, data areas are separated by a series of radially extending embedded servo sectors which are factory recorded with servo information at a single data transfer rate. A servo data recovery circuit asynchronously (i.e. without phase lock to incoming servo data) recovers a servo address mark, a track number and fine position information from information read by the data transducer while passing over each sector. The servo recovery circuit is separate from the read channel electronics employed for peak detection of user data information. This example is described in commonly assigned U.S. Pat. No. 5,420,730 to Moon, et al., entitled: “Servo Data Recovery Circuit for Disk Drive Having Digital Embedded Sector Servo”, the disclosure thereof being incorporated herein by reference.
One factor which has limited data storage densities in magnetic recording employing peak detection techniques has been intersymbol interference, arising when flux transitions are increasingly close to each other. One technique for increasing flux densities in magnetic recording while still accurately reading recorded data is to employ synchronous sampling data detection. This technique, frequently referred to as “partial response, maximum likelihood” (PRML) signaling, has provided some improved data storage densities, at the expense of increased circuit complexity, including a fast analog to digital conversion process, and channel equalization, either on the analog side or on the digital side of the signal stream, or both. An example of a disk drive employing PRML is given in commonly assigned U.S. Pat. No. 5,345,342, to Abbott et al., entitled: “Disk Drive Using PRML Synchronous Sampling Data Detection and Asynchronous Detection of Sector Servo”, the disclosure thereof being incorporated herein by reference. The approach described in this patent enabled special circuitry within the synchronous sampling data detection channel to asynchronously detect track number values in embedded servo sectors recorded at a constant servo data rate whereas the user data rate differed by radial data zone across the recording disk. The servo bursts were read and processed using conventional peak detection, and sample and hold techniques.
An improvement over the asynchronous servo sampling technique taught by the Abbott et al. patent referred to above is found in a later, commonly assigned U.S. Pat. No. 5,384,671 to Fisher, entitled: “PRML Sampled Data Channel Synchronous Servo Detector”, the disclosure thereof being incorporated herein by reference. In this approach a timing loop of the synchronous sampling data detection system is phase locked to servo information, the servo information including track address and fine position information is synchronously sampled and decoded. In this approach the servo preamble field is recorded as a conventional ¼T sine wave pattern, which corresponds to a 2T pattern in a peak detection channel (T representing a unit sample cell or interval).
While these prior approaches have worked well in their respective times, increasing data storage capacities and data transfer rates per unit size disk have led directly to a hitherto unsolved need for an improved disk drive head servo format and synchronous sampling servo detection method and architecture.
SUMMARY OF THE INVENTION WITH OBJECTS
A general object of the present invention is to provide improved and simplified methods, apparatus, and data format for providing information for positioning data transducer heads relative to data tracks in a disk drive including a partial response, maximum likelihood (PRML) synchronous sampling data detection channel.
Another object of the present invention is to provide a servo format and apparatus for a PRML disk drive which does not require separate peak-detection hardware for detecting embedded servo information.
Yet another object of the present invention is to reduce impact of radial incoherence upon a head position servo system of a disk drive thereby facilitating higher track densities in a manner overcoming limitations and drawbacks of the prior art.
A further object of the present invention is to provide a synchronous sampling servo information estimation method and apparatus which makes substantial use of circuit elements of a PRML synchronous sampling data detection channel, thereby reducing overall circuit complexity and cost while providing for robust recovery of the servo information.
A further object of the present invention is to provide a simplified address decoding method and apparatus within a PRML sampling data detection disk drive.
One more object of the present invention is to provide a more compact and higher efficiency servo address format enabling use of higher code rates, smaller cell times and less redundancy within embedded servo sectors which are synchronously sampled and detected within a PRML disk drive.
Yet another object of the present invention is to employ a species of bi-phase self-clocking code, known as “wide bi-phase code” for encoding head position servo information recorded within embedded servo sectors on a storage disk surface of a disk drive including a PRML synchronous sampling data detection channel, in a manner facilitating use of many channel elements during servo information recovery operations.
Still one more object of the present invention is to provide a most-significant-bit (MSB) detector for detecting wide bi-phase encoded head position servo information within a PRML synchronous sampling data detection channel of a hard disk drive.
Yet one more object of the present invention is to provide a plurality of servo burst detection architectures for detecting antipodal and frequency modulated servo burst patterns in order to produce head position error signals within a hard disk drive including a synchronous sampling data detection channel.
In accordance with principles of the present invention, a magnetic disk drive has at least one rotating magnetic data storage disk defining recording tracks divided into data sectors by narrow servo spokes. A data sector lying between servo spokes of a recording track on the disk is recorded with user data encoded in accordance with a code having a predetermined distance and user data code rate. Each servo spoke of the recording area has at least one servo information field encoded in a wide bi-phase pattern at a servo code rate which is selected to be reliably robust in view of the synchronously detected data code rate. The disk drive further includes a synchronous sampling data detection channel for synchronously sampling and detecting both the servo information field and the coded user data. The detection channel includes:
a data transducer head positioned by a servo-controlled head positioner over the recording track,
a preamplifier for receiving electrical analog signals magnetically induced by the data transducer head from flux transitions present in at least the servo information field,
a digital sampler for synchronously sampling the electrical analog signals to produce digital samples, and
wide bi-phase decoding circuitry including a most significant bit detector coupled to receive digital samples from the synchronous sampling data detection channel for decoding the coded wide bi-phase pattern.
In one aspect of the present invention, the data detection channel includes a chunk synchronizer for generating and applying a wide bi-phase synchronization signal to the most significant bit detector.
In another aspect of the present invention, the wide bi-phase magnet patterns recorded in plural servo information fields of each spoke are ++−− for a binary zero information value and −−++ for a binary one information value.
In another aspect of the present invention, one servo information field within each spoke comprises a track number binary pattern of predetermined bit length, the pattern being decoded as a wide bi-phase code and then decoded as a Gray code with a code rate of one. Also, the track number binary pattern may include a parity or cyclic redundancy check (CRC) symbol, and has circuitry for receiving and decoding the track number binary pattern and for checking the parity or CRC symbol.
In a further aspect of the present invention, one servo information field within each spoke comprises two track number binary patterns of predetermined bit length: a first track number being an address of the track, and a second track number being an address of a second track adjacent the track. In this aspect, the second track number may be recorded with a one-half track offset extending into the second track, and it may further include error correction code values calculated with respect to the first and second track numbers. In this aspect, error correction code decoding and correcting circuitry is coupled to the synchronous sampling data detection channel for decoding, checking and correcting the decoded values of the first and second track numbers.
As another facet of the present invention, a data recording disk has a pattern of radially spaced tracks and a plurality of circumferentially spaced angular servo sectors lying in data sectors. The servo sectors include prerecorded servo head positioning information for identifying track and sector locations, each of the servo sectors having at least one identification field including servo symbols encoded in accordance with a wide bi-phase code. Each of the data sectors is recorded with data symbols in accordance with a maximum distance code such that the servo symbols and the data symbols may be detected by passage through a single synchronous sampling data detection channel, such as a PRML channel, with which the disk is physically assembled and used.
These and other objects, advantages, aspects and features of the present invention will be more fully understood and appreciated upon consideration of the following detailed description of a preferred embodiment, presented in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
In the Drawings:
FIG. 1 is a block diagram of a disk drive read channel providing PR 4 and EPR 4 targets.
FIG. 2 is a schematic diagram of a recording surface of a disk in the disk drive.
FIG. 3 illustrates a signal recorded on a servo sector on a track of the disk.
FIG. 4 is a block diagram of the fields of the servo sector.
FIG. 5A is a graph of an analog signal response from a magnetic recording of a single write current pulse wherein the channel has been equalized to an EPR 4 target spectrum.
FIG. 5B is a graph of an analog signal response to e.g. a binary one (“−−++”) wide bi-phase write current sequence.
FIG. 5C is a graph of an analog signal response to e.g. a binary zero (“++−−”) wide bi-phase write current sequence.
FIG. 5D is a graph of an analog signal response to a wide bi-phase sequence e.g. a binary 100 sequence (“−−++++−−++−−”)
FIG. 6A illustrates a first servo sector layout for track numbers without radial interference.
FIG. 6B illustrates a second servo sector layout for track numbers without radial interference.
FIG. 7 is a block diagram of a portion of servo sector logic including a MSB detector, a chunk synchronizer, and an error generator.
FIG. 8 is a block diagram of a 1+D filter.
FIG. 9 is a block diagram of a chunk synchronizer.
FIG. 10 is a block diagram of a MSB detector.
FIG. 11 is a block diagram of an error generator.
FIG. 12 is a block diagram showing a burst detector in the servo sector block diagram.
FIGS. 13A-13E are diagrams illustrating servo bursts formats.
FIGS. 14A-14B are block diagrams of servo burst detectors.
FIGS. 15A-15B are block diagrams of alternative servo burst detector architectures based on the FIGS. 14A, 14 B approaches, respectively.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Turning to FIG. 1, a disk drive 10 incorporates a programmable and adaptive PR 4 , ML read channel. The disk drive 10 may be one of a variety of embodiments, such as that disclosed in commonly assigned U.S. Pat. No. 5,341,249 to Abbott et al., entitled: “Disk Drive Using PRML Class IV Sampling Data Detection with Digital Adaptive Equalization”, the disclosure thereof being incorporated herein by reference. (This patent is the parent of the Abbott et al. U.S. Pat. No. 5,345,342, referenced hereinabove.)
The drive 10 includes at least one data storage disk 16 . As is conventional, a data transducer head 26 , for example, a magneto-resistive head, is associated in a “flying” relationship over a storage surface of each disk 16 . The head 26 is positioned relative to selected ones of a multiplicity of concentric data storage tracks 71 defined on each storage surface of the rotating disk 16 , see FIG. 2 .
Embedded servo patterns are written in a conventional servo writing process during drive manufacturing on selected data storage surfaces of the disk 16 , see FIG. 2, for example, in accordance with the methods described in a commonly assigned U.S. Pat. No. 5,170,299, the disclosure of which is incorporated here by this reference. Alternatively, the drive 10 may self-write some or all of its servo patterns during a post-assembly servo writing process.
During reading, flux transitions sensed by head 26 as it flies in close proximity over the selected data track 71 are preamplified by a read preamplifier circuit 28 . The preamplified analog signal (or “read signal”) is then sent into an analog variable gain amplifier (VGA) 38 . After controlled amplification, the read signal is then passed through a programmable analog filter/equalizer stage 40 .
The analog filter/equalizer 40 is programmed so that it is optimized for the data transfer rate of the selected data zone 70 from within which the transducer head 26 is reading data. The equalized analog read signal is then subjected to sampling and quantization within a high speed analog to digital (A/D) converter 46 which, when synchronized to user data, generates raw data samples {x(k)} of at least five bits resolution.
An adaptive digital FIR filter 48 employs adaptive filter coefficients for filtering and conditioning the raw data samples {x(k)} in accordance with the desired PR 4 channel response characteristics in order to produce filtered and conditioned samples {y(k)}. The bandpass filtered and conditioned data samples {y(k)} from FIR filter 48 are then passed over a data bus path 49 to a Viterbi detector (not shown), which detects user data with the PR 4 target. In those embodiments using both a PR 4 and an EPR 4 target, the filtered and conditioned samples {y(k)} from FIR filter 48 are also passed through a target (e.g. 1+D) filter 50, the output path 51 of which provides the signal filtered to e.g. EPR 4 channel response characteristics. Other targets than PR 4 and EPR 4 are within the contemplation of this invention, and the target filter 50 would be adapted to the selected target. (If only a single PR 4 or EPR 4 target spectrum is desired, FIR filter 48 is programmed with appropriate coefficients directly, and a second target filter 50 is not needed.) The samples, including raw data samples {x(k)} and filtered samples {y(k)}, are taken at the data sampling rate, which has a clock bit time period T. This time T corresponds to a “bit cell” or, more simply, a “cell”, at the sampling rate. A timing loop 53 may receive e.g. the PR 4 target samples on path 49 and synchronize sampling and quantization by the analog to A/D converter 46 at desired sampling locations. Similarly, a gain loop 54 may control the VGA 38 based e.g. on error values produced by an error measurement circuit 58 connected to receive the e.g. PR 4 target samples on path 49 . A DC offset control loop (not shown in FIG. 1) may also be provided to adjust for DC offset based on the PR 4 target samples. A target detector 61 , which may include a path memory, such as a Viterbi detector, or a complexity-reduced target post-processor of the type described in commonly assigned U.S. Pat. No. 5,521,945 to Knudson, entitled: “Reduced Complexity EPR 4 Post-Processor for Sampled Data Detection”, the disclosure thereof being incorporated herein by reference thereto.
The drive 10 also includes a wide bi-phase detector 52 for detecting wide bi-phase encoded servo information symbols, in accordance with framing patterns generated by a chunk synchronizer 56 . The detector 52 and synchronizer 56 may receive servo symbol sample values on the path 49 , or the path 51 . The circuit also includes a synchronous burst detector 55 which likewise receives sample values either from path 49 or path 51 . A conventional servo fields decoder 63 receives, frames and decodes servo symbols from servo fields decoded by the wide bi-phase detector 52 , and may follow the approach shown in commonly assigned U.S. Pat. No. 5,420,730 to Moon et al., entitled: “Servo Data Recovery Circuit for Disk Drive Having Digital Embedded Sector Servo”, the disclosure thereof being incorporated herein by reference. Position error signals (PES) from the burst detector 55 and servo field information from the decoder 63 enter a servo control process circuit 65 wherein actuator current command values are generated. These values are applied to a head position servo driver circuit 57 and resultant driving currents are supplied to drive a voice coil motor (VCM) 69 which positions the head 26 .
Ideally, some or all of the elements 38 , 40 , 46 , 48 , 50 , 52 , 53 , 54 , 55 , 56 , 58 , and 63 may be included in one mixed-mode application-specific integrated circuits (ASICs), or in several analog/digital ASICs.
As shown in FIG. 2, an exemplary data storage surface of a storage disk 16 has multiple concentric data tracks 71 which are preferably arranged in a plurality of data recording zones 70 between an inner landing zone area LZ and a radially outermost peripheral data track zone 70 - 1 . In the illustrated example, the data tracks are shown as arranged into e.g. nine data zones including the outermost zone 70 - 1 , and radially inward zones 70 - 2 , 70 - 3 , 70 - 4 , 70 - 5 , 70 - 6 , 70 - 7 , 70 - 8 and 70 - 9 , for example. In practice, more zones are presently preferred. Each data zone has a bit transfer rate selected to optimize areal transition domain densities for the particular radius of the zone.
FIG. 2 also depicts a series of radially extending embedded servo sectors or “spokes” 68 which e.g. are substantially equally spaced around the circumference of the disk 16 . While the FIG. 2 depiction illustrates the servo spokes 68 as generally trapezoidal, in practice the servo wedges are slightly curved along the disk radial dimension. By way of the FIG. 3 overview, each servo sector 68 essentially includes a servo preamble field 68 A, a servo identification field 68 B, and a field 68 C of circumferentially staggered, radially offset servo bursts, for example. While the number of data sectors per track varies from data zone to data zone, the number of embedded servo sectors, e.g. 68 per track, remains constant throughout the surface area of the disk 16 , in the present example.
The servo sectors 68 are preferably recorded at a single data cell rate and with phase coherency from track to track with a conventional servo writing apparatus at the factory. Servo writing may be conventionally carried out by a laser servo writer and head arm fixture as described for example in commonly assigned U.S. Pat. No. 4,920,442, the disclosure of which is incorporated here by this reference. Alternatively, the servo sectors are written at zoned data cell rates, as described in commonly assigned U.S. Pat. No. 5,384,671, already discussed above. The disk drive may alternatively employ partial or complete “self servo write” techniques in order to carry out servo writing.
Turning to FIG. 4, each servo sector 68 or “spoke” has a servo identification field of embedded servo information such as is illustrated, for example. A optional DC erase field 731 of size e.g. 40 cells (illustrated in FIG. 4 with the time “40T” below the field) in a clean area on the disk with substantially no or a few transitions, which can be used to flag the onset of a servo sector 68 . A preamble field 732 of size e.g. 160 cells can be written in a 2T repeating pattern such as “−−++ −−++ −−++” of the desired length. The preamble 732 is used by timing and gain loops to establish correct gain and phase lock relative to the incoming analog signal thereby to control sampling quantization by the analog to digital converter 46 . Together, the optional DC erase field 731 and the preamble field 732 comprise the preamble field 68 A of FIG. 3 .
A servo address mark 733 is used to reset the framing clock. This is followed by the e.g. three least significant bits (LSBs) 734 of the track number. The full spoke number 735 is optional, although at least one bit of information should be provided to enable rotational position to be determined. The entire track number 736 is recorded at least once. The head number (not shown) may also be recorded as part of the servo addressing information. Together, the servo address mark 733 , the LSB field 734 , full spoke number field 735 comprise the servo identification field 68 B of FIG. 3 .
Following the addressing information, servo bursts 737 are recorded, which are used to determine head position with respect to track center, as will be described. Examples of a variety of servo patterns are given hereinafter. These patterns in field 737 correlate to the field 68 C of FIG. 3 . The lengths of some or all the fields of the servo sector 68 may be of programmable size. Other fields of information may also be recorded among or after the fields that have been described. For example, the drive may record servo burst correction values (BCVs) in a short field 738 located immediately after the last servo burst pattern 737 , as taught in commonly assigned, copending U.S. patent application Ser. No. 08/607,507 filed on Feb. 27, 1996, by Shepherd et al., entitled: “In-Drive Correction of Servo Pattern Errors”, the disclosure thereof being incorporated herein by reference.
We turn now to describe wide bi-phase encoding, which may be used for some or all of the digital data storing fields of servo sector 68 , such as the servo address mark 733 , LSB field 734 , spoke number field 735 and track number field 736 , for example. In writing digital data, one begins with an unencoded bit (that is, either a 0 or a 1), which is referred to as a symbol. Symbols are recorded on a disk by a coding that assigns one or more signs or magnets (+ or −) to a cell. (Somewhat ambiguously, the signs may also be referred to as being either 0 or 1.) In bi-phase code (a self-clocking code also known in the art as Manchester, frequency doubling, or frequency modulation code) two signs are used, and symbols may be encoded as follows:
1→+−
0→−+
We define a wide bi-phase (WBP) code, with code rate ¼, as follows:
0→++−−
1→−−++
The DC erase field 731 , which should have no flux transitions, cannot be WBP encoded.
The preamble field 732 may be WBP encoded with e.g. 40, or a programmable number of, WBP symbols ‘1’ (or cells “−−++”), for PLL and AGC lock.
The servo address mark (“SAM”) 733 may be a nine-symbol word ‘000100101’ encoded in WBP that marks the beginning of a servo block. This SAM has the property that all shifts (auto correlation) disagree in at least 5 positions and therefore allows for 2 independent errors without loss of synchronization. When appended to the preamble 732 just described, the sequence looks like ‘ . . . 1111111000100101’. This is a modified Barker sequence.
The track number 736 may be a 14 symbol address or larger that is first encoded with a normal Gray code (with code-rate=1) and then a parity symbol may be added. The result is WBP encoded. The parity symbol, if any, cannot be used at seek time but can be used at read time to detect single errors. Gray coding is used to avoid large errors when simultaneously reading two adjacent track addresses when the read head 26 is between tracks during track seeking operations.
In an alternative servo sector layout, track addresses (track numbers) are written twice in each servo sector 68 , and the paired track addresses are different from each other. In FIG. 6A, odd track addresses (A 1 , A 3 , A 5 , A 7 ) are written first and even track addresses (A 2 , A 4 , A 6 , A 8 ) are written second, in what appear as radial columns in the figure. In FIG. 6B, the second column records the same track number as does the first, but the second column is recorded with a half-track offset. In both formats, during track following every position of the read head 26 can read an address without interference from an adjacent track in at least one of the two columns. For this reason, Gray coding is not needed and one can append ECC fields to each address, as shown. In the first format (FIG. 6 A), the uncertainty is one track; in the second (FIG. 6 B), the uncertainty is half a track. In seeking, one may recognize the column to be read by using a position error signal from the servo bursts which have a period of two tracks. For this use, the servo bursts should be positioned close to the track addresses so that the radial position of the read head 26 does not change significantly from the time the head is reading the servo burst and the time it is reading the track addresses.
MSB Detector and Chunk Synch for WBP Codes
The WBP servo information coding arrangement described above is advantageously employed within a PRML sampling data detection channel in that many circuit elements of the channel may be used for recovering the servo information. For example, a single read channel application-specific integrated circuit (ASIC) may include a small amount of additional circuitry thereby enabling the ASIC to detect coded user data symbols as well as WBP coded servo information symbols. For example, a path sequence detector, such as a Viterbi detector 60 (FIG. 12) may be employed to detect the WBP coded servo information, as described for example in commonly assigned, copending U.S. patent application Ser. No. 08/686,998, filed on Jul. 24, 1996, entitled: “Wide Bi-phase Digital Servo Information and Estimation for Disk Drive Using Viterbi Detection”, the disclosure thereof being incorporated herein by reference. Alternatively, the WBP coded servo information may be recovered by a “most-significant-bit” (MSB) detector within the synchronous data detection channel. In an MSB detector, a series of points are sampled along a signal. When a transition is detected, the channel decides whether the transition is a logical “1” or a logical “0”. This may be determined by considering the most significant bit of the 2's complement of the sample point (e.g. 6 bit sample) and applying the following analysis: { MSB = 0 = logical “ 1 ” 1 = logical “ 0 ” }
Turning to FIG. 7, a most-significant-bit (“MSB”) detector 52 for detecting wide bi-phase codes may be connected to receive an EPR 4 target data stream from an output of a 1+D filter 50 . Alternatively, the MSB detector 52 may be connected to the input of the 1+D filter 50 to receive a PR 4 target data stream. MSB detector 52 uses phase information from chunk synchronizer 56 to decode WBP codes. The decoded data from MSB detector 52 is compared with raw data on filter 50 output path 51 in error generator 58 to generate error signals for the PLL, AGC and DC offset loops.
Turning to FIG. 8, 1+D filter 50 is shown in otherwise superfluous detail to illustrate the technique of separating computations into even and odd parts that is used to realize the required sample processing bandwidth with minimum clock frequency. Filter 50 receives odd and even 6-bit samples, pr 4 _o[ 5 : 0 ] and pr 4 _e[ 5 : 0 ], respectively, from FIR filter 48 . The samples are delayed at registers 501 and 502 , as shown, and summed at adders 503 and 504 , as shown, to produce 7-bit sums that are the odd and even EPR 4 samples, epr 4 _o[ 6 : 0 ] and epr 4 _e[ 6 : 0 ], respectively, through buffer registers 505 and 506 . Operating separately as it does with odd and even samples, filter 50 runs at 2T, half the channel clock rate.
Turning to FIG. 9, the chunk synchronizer 56 locks to the WBP symbols, that is, it locks to one of the four possible phases of the preamble sine wave (each phase is one cell apart). The chunk synchronizer 56 inputs the EPR 4 waveform from 1+D filter 50 and chooses one of the four cells as the reference cell from which the MSB detector will make a decision and the error generator 58 will generate errors. To accomplish this, it multiplies the incoming EPR 4 signal with two orthogonal reference signals for some window length, e.g. 12 cells and then accumulates the multiplied signals. The two orthogonal signals are, for example, in cell clock intervals,
1 0 −1 0 1 0 −1 0 . . . and
0 1 0 −1 0 1 0 −1 . . . .
Denoting the two accumulated values by acc_e and acc_o, for even and odd streams, respectively, the position of the phase of the preamble is estimated as follows:
pos[ 1 ]=|acc_e|>|acc_o|;
if (|acc_e|>|acc_o|) then
pos[ 0 ]=sign (acc_e)
else
pos[ 0 ]=sign (acc_o).
The two bits of position, pos[ 1 : 0 ], indicate the position of the ‘−’ to ‘+’ transitions in preamble. Recall that the preamble magnets (−−++ −−++ −−++ . . . ) may be thought of as a sequence of WBP-encoded 1's. Note that one cannot have a 0 sample in the middle of a WBP code series of multiple cells, i.e., a preamble field, because there is always a transition there. Thus, of the 5 ideal levels that can be sampled with an EPR 4 target (e.g., −1, −½, 0, ½, 1), only two are possible in the middle of a WBP code: −1 and 1. Because of the repeated ‘−−’ or ‘++’ before the transition, − ½ and ½ are also not possible there. Thus, the EPR 4 samples in the preamble will include a stream of regularly spaced +1's whose position indicates the center of the WBP code. This position is indicated by pos[ 1 : 0 ]. In practice, servo data input to the MSB detector 52 is given a polarity sign during transformation into servo samples by the analog to digital converter 46 .
The orthogonal reference signals ‘ . . . 1 0 −1 0 . . . ’ are implemented by a register 561 connected to alternate between values 1 and 0 and multiplexers 562 and 563 , which in response to the value from register 561 , output either their normal or their inverted input, thus alternating between multiplying the samples by 1 and −1. The high order e.g. 4 bits epr 4 _e[ 6 : 3 ] of the even samples are input into the 0 input of multiplexer 562 , and their inverse is input into the 1 input of the multiplexer. Similarly, the high order 4 bits epr 4 _o[ 6 : 3 ] of the odd samples are input into multiplexer 563 . Adder 564 sums the even sequence acc_e using register 565 to accumulate the result. Similarly, adder 566 and register 567 accumulate acc_o. The absolute values of acc_e and acc_o are compared in comparator 568 to generate the bit pos[ 1 ], and that bit is also used to select in multiplexer 569 the value of bit pos[ 0 ], either the sign of acc_e (i.e., acc_e[ 6 ]) or the sign of acc_o.
Turning to FIG. 10, MSB detector 52 , multiplexer 521 uses pos[ 1 : 0 ] from chunk synchronizer 56 which estimates the location of the WBP code center, to select one of four consecutive samples' high order bits as the decoded value of the WBP symbol. These 4 bits are epr 4 _o[ 6 ] 522 , epr 4 _o[ 6 ] delayed 2T 524 , epr 4 _e[ 6 ] 523 , and epr 4 _e[ 6 ] delayed 2T 525 . The 2T delays are provided by registers 526 and 527 , respectively, and these are clocked at half the cell rate. The inverted output of multiplexer 521 is provided through register 528 , which is clocked at one-quarter the cell rate, to provide one decoded symbol every 4T.
In an alternative embodiment, the MSB detector of FIG. 10 can provide error information as well as MSB decoding. By expanding registers 526 and 527 and multiplexer 521 to accept the full sample values (rather than just the high order bits, as illustrated), the output at register 528 is the entire selected sample, and not just its high order bit. The high order bit is still used to provided the decoded WBP symbol, but the entire value may now be used to generate an error signal if the selected value is closer than a threshold value to zero. (Recall that with WBP coding, the noiseless sample value should be either a maximum or a minimum and never zero.)
It will be appreciated by those skilled in the art that the WBP code is polarity sensitive, in that a “1” is defined as −−++ and a “0” is defined as ++−−. If, for example, a head transducer is reversed in polarity in the wiring connections, preamble and chunk sync (which are not polarity sensitive) will be detected, but a correct SAM and other data fields will not be read correctly, because chunk synchronization will be 180 degrees out of phase and the magnitude of the data sample will be inverted. In order to protect against a reversed polarity read element, a flip bit control flag is used. In this situation, a control processor or state machine will time out after a number of failed attempts have been made to detect a correct SAM, whereupon the flip control bit is set and the SAM searching sequence is repeated. The flip control bit is input to the Chunk Sync and MSB detector functions. Logic to correct for the polarity flip is:
1. if FLIP, then phase pos[ 1 : 0 ]=0 is actually what appears to be phase pos [ 1 : 0 ]=2.
2. if FLIP, then invert the MSB of the data passed to the MSB-Detector.
Turning to FIG. 11, error generator 58 first generates the ideal waveform from the output of MSB detector 52 and then subtracts that ideal waveform from the signal actually read to generate an error signal. The error signal and the ideal signal are used to update the phase detector, gain loop, and DC offset loop.
A pair of consecutive symbols decoded by MSB detector 52 are used as a two-bit index in lookup table 583 to select 4 values for the ideal EPR 4 waveform, using ref_pk[ 6 : 0 ] at input 581 as the peak value of the ideal waveform. (The earlier of the pair of symbols is provided by register 582 , which is clocked with the WBP period 4T.) The 4 values provided by lookup table 583 are tabulated below. (The peak value for the ideal waveform is shown as “r”.)
Current
Previous
Outputs
Symbol
Symbol
1
2
3
4
0
0
0
r
0
−r
1
0
−r/2
0
r/2
r
0
1
r/2
0
−r/2
−r
1
1
0
−r
0
r
The 4 values provided by table 583 for each symbol pair are selected by multiplexers 584 and 585 , which select alternate inputs on a 4T period, to produce through registers 586 and 587 the ideal even and odd EPR 4 waveforms, respectively. The 1, 2, 3 and 4 outputs of lookup table 583 are also the 1, 2, 3, and 4 inputs to a group of subtractors 591 .
Multiplexer 590 uses chunk synchronization phase pos[ 1 : 0 ] to properly match EPR 4 samples epr 4 _o[ 6 : 0 ] and epr 4 _e[ 6 : 0 ] from 1+D filter 50 to the ideal waveforms generated by use of lookup table 583 , which has just been described. The odd EPR 4 samples are provided undelayed at path 593 and are successfully delayed 2T by registers 593 a , 593 b , and 593 c , whose outputs are also provided to multiplexer 590 as shown. The even EPR 4 samples are similarly provided at path 594 and through registers 594 a , 594 b , and 594 c to multiplexer 590 . The following table shows the outputs 5, 6, 7, and 8 of multiplexer 590 based on the phase pos[ 1 : 0 ] and the even and odd EPR 4 sample values, denoted by y_e(k) and y_o(k). (The time index k increments in steps of 2T.)
Outputs
Phase
5
6
7
8
00
y_o(k)
y_e(k)
y_o(k-1)
y_e(k-1)
01
y_e(k)
y_o(k-1)
y_e(k-1)
y_o(k-2)
10
y_o(k-1)
y_e(k-1)
y_o(k-2)
y_e(k-2)
11
y_e(k-1)
y_o(k-2)
y_e(k-2)
y_o(k-3)
The ideal values from lookup table 583 are subtracted from the corresponding sample values from multiplexer 590 , by subtractor group 591 , as shown, so that the 1 output of table 583 is subtracted from the 5 output of multiplexer 590 , the 2 output from the 6 output, and so on. The results of these subtractions are the error signals, which are buffered through multiplexers 595 and 597 at a 4T period (corresponding with the WBP symbol input rate to lookup table 583 ), and then buffered through registers 596 and 598 to provide a stream of even and odd error signals err_e[ 6 : 0 ] and err_o[ 6 : 0 ], respectively.
Turning to FIG. 12, a Viterbi detector 60 for PRML detection of WBP codes with EPR 4 targets can be used to detect all VWBP-encoded digital information in the servo sector, such as track number, head number, and sector number. Viterbi detector 60 may be a difference-metric detector or a tree search detector, or a conventional Viterbi detector, as described in commonly assigned, copending U.S. patent application Ser. No. 08/686,998, filed on Jul. 24, 1996, and entitled: “Wide Bi-phase Digital Servo Information and Estimation for Disk Drive Using Viterbi Detection”, the disclosure thereof being incorporated herein by reference. Alternatively, in place of an EPR 4 detector, WBP-encoded data in the servo sector may be decoded by a Viterbi detector for WBP codes with PR 4 targets, such as a difference-metric detector or a tree-search detector, or by a conventional Viterbi detector, also as described in the copending patent application referred to hereinabove.
Returning to FIG. 12, a digital servo burst detector 55 also receives the EPR 4 target output signal from target filter 50 . Alternatively, burst detector 55 may receive a PR 4 target from the output of the FIR filter 48 , where burst formats are used that can be detected with e.g. a PR 4 target.
Turning to FIGS. 13A-13E, five servo burst formats will be described. The centers of the data tracks are indicated by TK 0 , TK 1 , TK 2 , and TK 3 . The bursts in each format repeat with a period of two servo tracks. The first format, which we will call the type I format, i.e. full track bursts, is illustrated diagrammatically in FIG. 13 A. The type I bursts A, B, and C (and, optionally, D) are written to be the width of a data track. Because the write head is less than this wide, the bursts are written in at least two passes and at least one erase band (not shown) will be found within each burst. There is also an erase band (not shown), for example, between burst A and burst C, that runs along TK 1 .
The second format, which we will call the type II format, i.e. narrow bursts, is illustrated diagrammatically in FIG. 13 B. In this format, each burst, E, F, G, and H, is written only once; thus there is no erase band within the burst. The distance between radially adjacent bursts (such as E and F) is half a track width. The write head will generally exceed this width, so each burst will normally extend over one track center.
In both type I and type II formats, the bursts themselves are normally sinusoids of constant frequency and amplitude.
The third format, which we will call the antipodal format, is illustrated diagrammatically in FIG. 13 C. In this format, the bursts—J, K, L, and M—are written to fill the space left blank, for example, between the A and B bursts in the type I format (FIG. 13 A). The unrecorded areas are filled with a sinusoidal waveform of opposite (or antipodal) polarity. Thus, if the signal in burst J is sin(x), the signal in burst K is −sin(x). The waveforms in bursts L and M correspond to those of bursts J and K.
Unlike the situation with type I and type II, phase information is important in the antipodal format. Thus, the PLL sampling phase is locked and not updated while reading this burst format, so as not to “correct” the phase information. For the same reason, this format is subject to errors arising from the erase band within the bursts, radial phase incoherence, and accumulated phase error. To allow the disk drive to limit the effect of such errors, an optional resynchronization pattern (not shown) may be recorded before bursts themselves, as taught in the above-referenced, copending U.S. patent application Ser. No. 08/320,540 filed on Oct. 11, 1994, entitled: “Synchronous Detection of Concurrent Servo Bursts for Fine Head Position In Disk Drive”, now U.S. Pat. No. 5,576,906, the disclosure thereof being incorporated herein by reference.
The fourth format, which we will call the compressed format, is illustrated diagrammatically in FIG. 13 D. This format is like type I in form, with the difference that, unlike the situation with the other formats, in compressed format the servo information is written on spoke tracks SPOKE TK 0 , SPOKE TK 1 , SPOKE TK 2 , and SPOKE TK 3 that do not correspond to the data tracks, which here are denoted DATA TK 0 , DATA TK 1 , and DATA TK 2 . Each burst P, Q, R, and S is written only once; thus there is no erase band within the bursts and the bursts are nevertheless the full width of the servo track. Note that with this format, in tracking an odd numbered data track, such as track DATA TK 1 , the disk drive will not be following a servo track center. In fact, the head will ideally be placed exactly between two servo tracks, and the two-track periodicity of the burst format must be used to resolve the track number ambiguity between the Gray coded numbers received from spoke tracks SPOKE TK 1 and SPOKE TK 2 while tracking data track DATA TK 1 , for example.
The fifth format, which we will call the frequency format, is illustrated diagrammatically in FIG. 13 E. In this format, unlike the ones previously described, the burst waveforms are not all recorded at one frequency. The frequency format bursts are recorded across the full radial width of the half tracks. As illustrated in FIG. 19E, the radial sequence of bursts S, T, U, and V are recorded as sinusoids with angular frequencies w 1 and w 2 , so that the form of the sequence of bursts is: S is sinw 1 t; T is sintw 2 ; U is −sinw 1 t, and V is −sinw 2 t. The two frequencies must be different and should be selected to have no intersecting harmonics.
Turning to FIGS. 14A-14B, burst detector 54 will take different forms depending on the format in which the servo bursts are recorded. Turning to FIG. 14A, burst detector 541 is useful for synchronous formats such as the antipodal format and the frequency format. Multiplier 542 multiplies the EPR 4 sample waveforms by a sine wave 1 0 −1 0. The result is accumulated by adder 543 in register 544 . The output of the detector from register 544 represents the signed amplitude of the (generally) composite signal produced by two radially adjacent bursts, such as bursts K and J of FIG. 19 C. This output will ideally be zero when the read head is exactly between the two bursts and on, for example, the track TK 1 .
Turning to FIG. 14B, burst detector 55 is useful for non-synchronous burst formats such as the type I, the type II, and the compressed formats. Burst detector 55 calculates a phase-amplitude vector of the burst signal by multiplying the EPR 4 sample waveforms by two orthogonal sine waves with a phase offset of 90°; the first sine wave 1 0 −1 0 is used in multiplier 551 , adder 552 , and accumulating register 553 ; the second, orthogonal, sine wave 0 −1 0 1 is used in multiplier 554 , adder 555 , and accumulating register 556 . The result of this process is a phase-amplitude vector whose real part is in register 553 and whose imaginary art is in register 556 . When the burst has been read, the amplitude of the burst is calculated as the square root, circuit 560 of the sum, adder 559 , of the squares of the real part, circuit 557 , and the imaginary part, circuit 558 , of the phase-amplitude vector. This calculated amplitude estimates the degree of overlap between the burst and the read head and is used later to estimate the head position with respect to the repeating two-track burst pattern. (Note than in the non-synchronous type I, type II, and compressed burst formats under consideration, no two bursts are radially adjacent, so the burst detector will have only one burst to process at a time.)
Two alternative burst detectors for the frequency format will now be described. The first alternative operates as a pair of the FIG. 14A burst detectors 541 as illustrated in FIG. 15 A. The sine wave input to the first detector 541 A of the pair has an input to multiplier 542 which is a sine wave with an angular frequency of ω 1 . The second detector 541 B has a sine wave input to its multiplier 542 at an angular frequency of ω 2 . The output of each detector 541 A, 541 B is the signed amplitude of the burst signal at the corresponding angular frequency, and these signed amplitudes are compared in a comparison circuit 545 to estimate the position of the read head.
The second alternative burst detector for the frequency format, unlike the first alternative just described, is not sensitive to radial phase incoherence or phase error. The second alternative, shown in FIG. 15B, duplicates the operation of a pair of the burst detectors 55 illustrated in FIG. 14 B. The sine wave input to multipliers 551 and 554 in the first of the pair of detectors 55 A has an angular frequency of ω 1 . The sine wave input to the multipliers 551 and 554 of the second detector 55 B has an angular frequency of ω 2 . The outputs of the two detectors 55 A and 55 B, each of which estimate the unsigned amplitude of the burst signal at the corresponding frequency, are compared by a comparison circuit 546 to estimate the position of the read head.
Having thus described an embodiment of the invention, it will now be appreciated that the objects of the invention have been fully achieved, and it will be understood by those skilled in the art that many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the spirit and scope of the invention. The disclosure and the description herein are purely illustrative and are not intended to be in any sense limiting. | A magnetic disk drive data storage disk defines recording tracks divided into data sectors by narrow servo spokes. A data sector lying between servo spokes is recorded with user data encoded in accordance with a code having a predetermined distance and user data code rate. Each servo spoke of the recording area has at least one servo information field encoded in a wide bi-phase code pattern. The disk drive further includes a synchronous sampling data detection channel having a data transducer head positioned by a servo-controlled actuator over the recording track, a preamplifier for receiving electrical analog signals magnetically induced by the data transducer head from flux transitions present in at least the servo information field, a digital sampler for synchronously sampling the electrical analog signals to produce digital samples, and wide bi-phase decoding circuitry coupled to receive digital samples from the synchronous sampling data detection channel for decoding the wide bi-phase code pattern. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The present invention relates generally to systems and methods of configuring marine vessel hulls with combination hull arrangements, and more specifically to systems and methods of configuring a hull with combination hull arrangements that utilize aerodynamic and hydrodynamic effects to provide broader ranges of performance benefits than are provided by uncombined hull arrangements.
[0005] 2. Related Art
[0006] Marine vessels may encounter widely varying conditions and can be asked to perform well in a broad range of tasks. A broad variety of hull arrangements have been devised in order to provide performance benefits that are particularly well suited for certain tasks or conditions. While many of these individual hull arrangements are advantageous for accomplishing certain objectives they have been devised for, there often are also significant limitations in the range of situations in which they are capable of performing well. These limitations can be generally characterized in at least one of two ways. The first characterization is the type of function at which the vessel can perform well, and the second characterization is the type of conditions in which the vessel can operate well. Frequently, limitations characterized in one way are also capable of being characterized in the other way.
[0007] For marine vessels, designs intended to provide certain functional capabilities must also take into account both the conditions in which the vessel will normally operate, as well as the potential for the vessel to encounter less customary or even extreme conditions. Often, designs are primarily optimized for the normal operating conditions, while some provision, often limited, is made for the less common conditions. For example, a V-hull design provides capabilities of traversing waters with significant waves while lessening their jarring effects by virtue of its ability to “cut” through the waves. However, a V-hull is also susceptible to greater rolling, for example due to steering changes, and is less efficient when moving at high speeds across relatively calm waters than are flatter bottom hulls or catamarans which will normally plane more easily. By the same token, those hulls that plane most easily, and hence are more efficient for travel at higher speeds, are also more susceptible to being adversely affected by larger waves, and their uses can be limited by their difficulties in handling turbulent waters.
[0008] One approach to surmounting these limitations has been to develop hull designs that amalgamate aspects of disparate hull designs. Hulls which attempt to combine the virtues of both V-shapes and efficient planing bottom shapes are frequently compromises that may not perform either task optimally, but hope to at least avoid the worst performance problems of both. In some designs, hull step(s) are also utilized to attempt to facilitate easier planing. While some of these approaches have managed to avoid various performance deficits of certain single-shape hull designs, or expand the range of conditions in which a vessel can operate well, there remain substantial amounts of improvement in both performance gains and reductions in condition-based limitations that are desirable, but not yet available.
SUMMARY OF THE INVENTION
[0009] The present invention encompasses both systems and methods of arranging marine vessel hulls that blend a generally V-shaped fore hull portion with an aft hull portion that is capable of achieving a planing attitude more readily than a conventionally V-shaped hull. Hull arrangements of many embodiments of the present invention will incorporate what is termed herein a slot aspect that is comprised of at least one downwardly opening recess formed into the underside of portions of, or all of the vessel's hull. The slot aspect is frequently arrayed along the longitudinal axis of the marine vessel, and usually extends rearwardly to at least the vicinity of the vessel's transom. While the slot aspect, in various embodiments of the present invention, assumes differing transverse cross-sections and longitudinal lengths, in general it is of distinctly greater length than width or depth.
[0010] Several embodiments according to the present invention comprise marine vessel hull arrangements that also incorporate at least one topographic feature that facilitates ventilation of the underside of the hull. The topographic feature(s) provides a form of channeling action that is capable of aerodynamically influencing air from the atmosphere to access the region immediately below the hull portion, when the marine vessel is in forward motion at an appreciable rate of travel. Most often, the topographic feature will be disposed so as to facilitate ventilation of the region of the hull's underside that is in contact with the water when the vessel is either approaching or at planing speed. When a marine vessel approaches planing speed, it can experience a need for a substantial power input to transition from a displacing attitude to a planing attitude. This effect is particularly pronounced for step hulls that can create a lower pressure area in the space immediately aft of the step when accelerating, since the hull's partial lifting out of the water produces a void that water is induced to attempt to fill if the area is not ventilated, which thereby works against the hull's ability to transition to a planing attitude. The ventilating effect of the topographic feature is capable of at least partially mitigating this lowered-pressure effect between the hull's underside and the water surface that can result when a vessel's speed increases both in stepped and non-stepped hull arrangement embodiments according to the present invention. In those embodiments that include a slot aspect as well, the topographic feature influences air to specifically access the region of the slot aspect. In embodiments of the present invention that involve hull arrangements incorporating at least one step, the topographic feature(s) will generally influence air to access the region immediately trailing the step(s). Frequently, but not exclusively, the topographic features will be arranged in pairs, disposed symmetrically on opposite sides of the marine vessel's longitudinal axis.
[0011] The myriad benefits of the slot-V hull system include, but are not limited to:
a) Increased longitudinal stability due to the slot aspect providing an effect analogous to that of a keel fin or keel plate, but with neither the increased drag nor the greater draft of such a keel. b) Reduction in roll caused by rough water or steering changes, due to the capability of utilizing a flatter bottom than is normally available for a vessel that also provides a V-hull's benefits. c) Reduction in lateral sliding in turns, particularly at high speeds, again due to the slot aspect's providing of a keel-plate-like effect. d) Reduction in drag induced by the component of the water displacement that is normal to the hull surface, due to the elimination of the further downward extension of the hull, in the region of the slot. This reduction in drag permits a higher maximum speed with the same propulsion power, or alternatively a similar maximum speed with less propulsion power than is normally available for a vessel that also provides a V-hull's benefits. e) Reductions in the power output, fuel consumption, and time required for the vessel to reaching a planing attitude due to enhanced capabilities of ventilating selected regions of the hull's underside. f) Provision of a more comfortable ride due to reduced lateral roll, and deceleration forces. g) Reduction in overall vessel cost in comparison to a vessel of similar size and performance, due to construction cost being comparable to a similarly sized V-hull, while engine costs are reduced by the lesser demand in propulsion power and fuel consumption costs are reduced due to greater operating efficiency.
[0019] Embodiments of the present invention are well suited for a broad range of applications as well. Effectively any planing water craft design and/or construction that could utilize a conventional V-bottom hull is likely also capable of benefiting from the advantages provided by the slot-V hull system, advantages which are not available to a hull made from a conventional V-bottom design. Additionally, many vessels which would have not previously been constructed with any form of a V-bottom hull due to functional or environmental considerations, can now utilize the slot-V hull system to address those considerations and still take advantage of the benefits of a V-bottom hull. The slot-V hull system, due to a wide variety of design parameter flexibilities, is capable of being customized for optimal application across an extensive scope of situations. The design parameters that can be varied include, but are not limited to, slot aspect width, depth, length, and forward terminus disposition; manners of disposition and utilization of the topographic feature(s) for ventilation; incorporation of one of more steps in the hull bottom; methods of combining various numbers of the assorted parameters that are described individually or in combinations herein; as well as permutations of the constituents of these combinations.
[0020] While the range of vessels and means of employing the slot-V hull system is quite sizable, a representative vessel designed according to one embodiment of the present invention provides an illustrative example of an application of the slot-V hull system. Many factors can influence the design process for a hull arrangement when optimizing applications of the slot-V hull system. These factors may include parameters of the vessel under construction such as length, beam, depth, weight, power, dead rise angle, bow shape, hull composition, presence and aspects of chines, strakes, steps, as well as numerous other attributes. Further factors may also include anticipated operating environment aspects such as waves, swells, wakes, wind, altitude, water salinity, and many others; in addition to desired performance factors such as speed, ride quality, stability, handling, time-to-on-plane, acceleration, rough water capabilities, turn radius at speed, and several additional factors. For an exemplary vessel with the dimensions of length≈30 feet, beam≈8½ feet, hull depth≈4 feet, weight≈5000 lbs., dead rise angle≈24°, with strakes, with 2 steps, constructed of fiberglass, and having an engine capable of≈500 hp power output; said exemplary vessel projected to operate in an environment with waves≈2-3 feet, swells≈2-3 feet, wakes≈2-3 feet, wind ranging from 0-40 mph, altitude ranging from 0-2000 feet, and fresh water operation; said vessel's desired performance including capabilities of 60-75 mph speed, acceleration from 0-60 mph in≈15 seconds, good ride, excellent stability, excellent handling, and time-to-plane≈4 seconds; the application of the slot-V hull system would include a hull arranged with 2 steps, a slot aspect extending aftward from the first step through past the second step to the transom, two pairs of topographic features (each pair having one topographic feature each arrayed on opposite sides of the vessel and disposed so that each pair would facilitate ventilation of a different step), wherein the slot aspect would have the dimensions of width≈10-15% of the vessel's beam, length of≈60-80% of the vessel's overall length, and depth (i.e. upward recess height) of≈2-4% of the vessel's beam. Alternatively, an exemplary vessel could be similarly arranged except with only a single topographic feature that extends forward from the slot aspect along the vessel's longitudinal axis to a graduated initiation along the upward curve of the vessel's bow. In either case, it should be understood that these examples are only illustrative of two applications of embodiments of the present invention, and are not limiting of the number or variety of embodiments that fall within the scope of the slot-V hull system, nor are they limiting of the number or variety of possible applications of any of the embodiments of the slot-V hull system.
[0021] Other objects and features will be in part apparent and in part pointed out hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1 depicts an upward and forward perspective view from a below, to the right side, and behind vantage point of a marine vessel hull arrangement according to a first embodiment of the present invention. In the present specification and claims, for purposes of consistency, the terms left and right are utilized in lieu of port and starboard, respectively, when referring to the sides of a marine vessel, and it should be understood that when these terms are utilized in reference to the relative side of a vessel, they refer to right and left as seen when facing the vessel from the rear in the direction of the vessel's forward motion, with the vessel in an upright orientation. In these circumstances then, the left side corresponds to port, and the right side corresponds to starboard.
[0023] FIG. 2 depicts an expanded detail view of the area bounded by the dashed circle 2 of FIG. 1 , showing the circumscribed portion of a first topographic feature arrangement.
[0024] FIG. 3 depicts an expanded detail side-view of a second topographic feature arrangement, showing the extent of said second topographic feature from the area of dashed circle 2 in FIG. 1 down to the bottom of the vessel hull.
[0025] FIG. 4 depicts an expanded detail view of the area bounded by the dashed circle 2 of FIG. 1 , showing the circumscribed portion of the second topographic feature arrangement.
[0026] FIG. 5 depicts a schematic detail cross-section view of a first step arrangement.
[0027] FIG. 6 depicts a schematic detail cross-section view of a second step arrangement.
[0028] FIG. 7 depicts a schematic detail cross-section view of a third step arrangement.
[0029] FIG. 8 depicts an upward and forward perspective view from a below, to the right side, and behind vantage point of a marine vessel hull arrangement according to a second embodiment of the present invention.
[0030] FIG. 9 depicts an expanded detail view of the area bounded by the dashed circle 9 of FIG. 8 , showing the circumscribed portion of a fourth topographic feature arrangement.
[0031] FIG. 10 depicts an upward view from a below vantage point of the second embodiment of the present invention.
[0032] FIGS. 11 A-F depict schematic detail cross-section views of the lower outer hull surface of the second embodiment of the present invention, wherein views A-F correspond to the views along cutlines 11 (A)- 11 (F), respectively.
[0033] FIG. 12 depicts an expanded detail view of the area within dashed circle 12 of FIG. 8 , illustrating a first slot aspect appendage.
[0034] FIG. 13 depicts a first moveable slot aspect appendage that is also typically disposed within the expanded detail view of the area within dashed circle 12 of FIG. 8 (not shown in FIG. 8 ), as it would be disposed in relation to a second hull arrangement of a second embodiment of the present invention.
[0035] FIGS. 14 A-N depict cross-sectional views of a number of variant embodiments of slot aspects according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0036] In the following description, identical numbers indicate identical elements. Where an element has been described in one Figure, and is unaltered in detail or relation in any other Figure, said element description applies to all Figures.
[0037] In FIG. 1 , a first embodiment of the present invention shows the underside of a first hull arrangement 110 for a marine vessel. The first hull arrangement 110 includes a transom 112 , a first hull bottom surface 113 , a right vessel side 114 and a left vessel side (not shown), a right chine 116 and a left chine 118 , a keel 120 , and a bow 122 . the first hull arrangement 110 further includes an aft slot aspect section 124 , a fore slot aspect section 125 , an aft step 126 , and a fore step 128 . A pair of aft topographic features 130 and a pair of fore topographic features 132 are arranged to flow into the aft step 126 and the fore step 128 , respectively. The right and left aft topographic features 130 , as depicted, are essentially mirror images of each other and are disposed symmetrically about a longitudinal plane of symmetry of the vessel, as are the right and left fore topographic features 132 . Each of the pairs of aft topographic features 130 and fore topographic features 132 flow into the aft step 126 and fore step 128 , respectively. In the FIG. 1 depiction of the hull arrangement 110 , the transitions from the aft topographic features 130 and the fore topographic features 132 to the aft step 126 and the fore step 128 , respectively, are continuous without distinct demarcations, but alternative embodiments with distinct and/or discontinuous transitions are also within the scope of the present invention. In operation, when the vessel is moving forward at speed through the atmosphere, air flows along the side 114 of the vessel and first encounters the fore topographic feature 132 at its forward upper end 134 in the region of dashed circle 2 . While the transition from the vessel side 114 to the forward upper end 134 can be continuous or discontinuous, one particularly useful form of transition is a continuous, graduated change in surface angle, from the nearly flat (in the vicinity of the forward upper end 134 ) surface of the side 114 to the curving surface of the fore topographic feature 132 . This transition from the vessel side 114 to the forward upper end 134 can range from very gradual to distinctly abrupt, depending on the requirements and design choices involved in the vessel's construction. Due to well known properties of laminar flows (defined as “a nonturbulent flow of a viscous fluid in layers near a boundary”, and in this case an air flow immediately adjacent the boat surface is substantially a laminar flow), as well as other aerodynamic effects, the air flowing along the side 114 will tend to continue following along the surface and thereby tend to begin to flow along the fore topographic feature 132 . At least some portion of the airflow that is thus induced to begin following along the fore topographic feature 132 will be influenced to continue along the course of the fore topographic feature 132 and access and ventilate both the region immediately aft of the fore step 128 plus the region of the fore slot aspect section 125 . While the first hull arrangement 110 as shown in FIG. 1 includes two steps, two separate slots, and two pairs of topographic features, hull arrangements with differing numbers of steps (from none through to more than two), with differing numbers and/or configurations of slots (again from none through to more than two, as well as a single slot aspect spanning more than one step), and differing numbers of topographic features (once again from none through to varying numbers, as well as unsymmetrical arrangements of topographic features) are all also within the scope of the present invention.
[0038] In FIG. 2 , the region circumscribed by dashed circle 2 of FIG. 1 is shown in greater detail so as to more fully illustrate the interrelationships of the surfaces that comprise the exterior of the vessel hull in that region. The aft topographic feature 130 and the fore topographic feature 132 are seen to be configured with a first set of contours, wherein the first set of contours involves a discontinuous step upward in the surface of the hull bottom, from a pre-topographic feature surface 210 to a post-topographic feature surface 212 . The fore topographic feature 132 transitions from the pre-topographic feature surface 210 to the post-topographic feature surface 212 with a guide surface 214 that is substantially at right angles to both the pre-topographic feature surface 210 and the post-topographic feature surface 212 . As shown in FIG. 2 , the transition at the upper forward end 134 between the right vessel side 114 and the guide surface 214 is graduated. The degree of this gradation shown in FIG. 2 is slightly limited, and is depicted to illustrate that a range of types of transitions are within the scope of the present invention, said range extending from a fully graduated continuous transition through to a sharply discontinuous transition. Though in many cases a fully graduated transition may provide benefits, in other cases a limited degree of gradation may be beneficial due to potential gains in hull integrity, reduced fabrication costs, and other factors.
[0039] In FIG. 3 is shown a second topographic feature 310 that is arranged with a second set of contours. The view of FIG. 3 is from a side perspective, showing the portion of the vessel hull that extends from the chine 116 down to the keel 120 and the fore slot aspect 125 . The spatial disposition of the second topographic feature configuration 310 is similar to that of the topographic features 130 and 132 . The primary difference between the topographic features 130 and 132 and the second topographic feature 310 are due to the variations between the first and second sets of contours. In FIG. 4 is shown a third topographic feature 410 that is arranged with a third set of contours. The view of FIG. 4 is substantially the same as the view of FIG. 2 . The spatial disposition of the third topographic feature configuration 410 is also similar to that of the topographic features 130 and 132 . The primary difference between the topographic features 130 and 132 , the second topographic feature 310 , and the third topographic feature 410 are due to the variations between the first, second, and third sets of contours. These differences are described in more detail in the descriptions of FIGS. 5, 6 , & 7 following.
[0040] FIGS. 5, 6 , and 7 depict a cross-section view of three alternative configurations for at least one of the steps 126 and 128 . While the three step configurations depicted in FIGS. 5, 6 , and 7 do vary significantly, they do not represent the entire span of step configurations that fall within the scope of the slot-V hull system, but rather are only illustrative of some of these varieties and are not intended to be limiting. The step configurations depicted in FIGS. 5, 6 , and 7 are also illustrative of some of the varieties of the topographic features' sets of contours as well, though again they are not limiting of the full range of the topographic features' sets of contours that lie within the scope of the slot-V hull system. In many cases the contours of a topographic feature and the configuration of the step whose ventilation it facilitates will closely correspond, but this is not required, and in certain embodiments of the present invention substantial differences may prove preferable. Additionally, it may prove beneficial to have a particular topographic feature that facilitates the ventilation of a fore step and which has a close correspondence in contours to the configuration of that fore step, whereas another topographic feature which facilitates the ventilation of an aft step does not have a close correspondence between its contours and the configuration of that aft step, or vice-a-versa.
[0041] In discussing the contours of topographic features it is useful for clarity of description purposes to define a topographic feature-specific coordinate system. Such a topographic feature-specific coordinate system can be defined relative to a general course that the ventilating airflow is influenced to follow by the topographic feature. One such general curvilinear airflow course coordinate system is defined herein as consisting of a course length dimension that follows the general route of the ventilating airflow, a course width dimension in a direction transverse to the length direction and generally parallel to the hull exterior surface, and a course depth dimension in a direction transverse to the length direction and generally normal to the hull exterior surface. Referring then to this curvilinear airflow course coordinate system, the plane in which FIGS. 5, 6 , and 7 are disposed is perpendicular to the course length dimension, with the course width dimension being horizontally disposed and the course depth dimension being vertically disposed in FIGS. 5, 6 , and 7 . The variations between differing forms of steps and/or topographic features can be subdivided then into two primary classes. A first class generally includes differences in the course length dimension, such as variations in the length of the route the airflow follows or variations in the layout along the vessel hull that a specific airflow route follows. A second class generally includes variations in the cross-section of the step and/or topographic feature that the airflow passes, the second class being describable in terms of the course length dimension and the course width dimension such as the three cross-section variations depicted in FIGS. 5, 6 , and 7 .
[0042] In FIG. 5 a first step cross-section 510 is schematically depicted with the forward motion direction of the vessel being indicated by arrow 512 . The elements of the first step cross-section 510 (as well as the step cross-sections depicted in FIGS. 6 and 7 ) are described herein, where applicable, in reference to the forward motion direction of the vessel such that a portion of the step cross-section that is forward of the step is indicated by the prefix “pre” and a portion of the step cross-section that is aft of the step is indicated by the prefix “post”. A pre-step hull bottom surface section 514 extends downwardly further than does a post-step hull bottom surface section 516 by a distance that is approximately equal to the height of a first step surface 518 . The first step surface 518 is disposed approximately perpendicularly to the pre-step hull bottom surface 514 and the post-step hull bottom surface 516 . For ease of manufacturing, it is generally preferable that the first hull arrangement 110 be capable of construction with a single mold, when constructing the marine vessel from fiberglass for example, and removal of the molded hull from the mold (referred to as mold relief) is aided by the first step included angle 520 being greater than 90° by at least 1 or 2 degrees. As the marine vessel moves forward at increasing speeds, water flows past the first hull bottom surface 113 in the opposite direction of arrow 512 . Once the vessel has reached a certain speed, the flow of water past the first step cross-section 510 approximately takes the path 522 , wherein it separates from the post-step hull bottom surface 516 for a certain distance. A spray flow also separates from the post-step hull bottom surface 516 once it passes the first step cross-section 510 , although the spray flow path 524 tends to rejoin the immediate proximity of the post-step hull bottom surface 516 at a lesser post-step distance than does the water flow path 522 . The term “spray” is used herein as an approximate description indicating a mixture of air and water in relatively equal parts. The spray flow path 524 is defined for purposes of description, and does not indicate a strict demarcation since the spray is a relatively amorphous entity that varies continuously in composition between greater and lesser portions of water relative to air. In general, the composition of the spray tends to contain a relatively greater proportion of air closer to a first post-step void 526 , and tends to contain a relatively greater proportion of water closer to the water flow path 522 . The spray flow path 524 is indicated herein to generally depict a path of the portion of the spray that has sufficient water density to be capable of producing a significant impulse when impacting a surface. Therefore, the spray flow path 524 generally indicates a trajectory that is capable of producing significant drag on the vessel if it impacts a portion of the hull bottom surface that substantially impedes the progress of the spray flow. As can be seen in FIG. 5 , this is a less significant effect for the first step cross-section 510 , but it can be a more significant effect for other step cross-sections such as those depicted in FIGS. 6 and 7 .
[0043] The first post-step void 526 is generally filled with water when the vessel is at rest, or traveling forward at slower speeds. As the vessel's speed increases, it tends to lift upward which, in combination with its forward motion, will produce a region of reduced pressure in the first post-step void 526 . This reduced pressure in the first post-step void 526 will pull water and/or spray with a greater water density up into the first post-step void 526 and thereby tend to oppose the transition of the vessel to a planing attitude. In order to avoid this planing attitude opposing effect, the slot-V hull system facilitates ventilation of the first post-step void 526 , most commonly through the ventilation facilitating action of the topographic features employed, although it is also within the scope of the present invention to also utilize alternative ventilation means, either in combination with at least one topographic feature or as an alternative to the use of topographic features. There are a significant variety of alternative ventilation means that are well know to those of skill in the art, including passive, powered, and engine exhaust gas ventilation systems. These preexisting means of ventilation differ in operation or construction from the inventive topographic features as described herein, in that they do not operate passively, extend both forward and upward from the region being ventilated, and are entirely a hull surface feature which does not entirely surround at least some portion of the route followed by the ventilating airflow. The inventive topographic features described herein, such as those depicted in FIGS. 5, 6 , and 7 , as well as the other topographic feature embodiments that fall within the scope of the present invention, will inherently act to facilitate the ventilation of the first post-step void 526 when the marine vessel's speed increases, which is the same condition that tends to create the first post-step void 526 . Topographic features according to the slot-V hull system are thus seen to be capable of autonomously mitigating creation of reduced pressure in any or all of the first post-step void 526 , and the aft slot aspect section 124 , the fore slot aspect section 125 , when the marine vessel's speed increases so that the vessel can reach, and then maintain, a planing attitude more quickly, with lesser power and fuel consumption requirements.
[0044] Certain alternative embodiments (not shown) of the present invention have hull arrangements which do not include a slot. Certain of these alternative hull arrangements have at least one post-step hull portion with a significantly lesser dead-rise angle than that of at least one pre-step hull portion. This greater flatness of the post-step hull portion is also capable of giving rise to the planing attitude opposing effect described in the immediately prior paragraph. These slotless embodiments will generally also include at least one topographic feature that facilitates ventilation of the region of the first post-step void 526 and thereby also facilitates the marine vessel's transition to a planing attitude. Though these embodiments are not explicitly depicted herein, their particulars are readily construed from the embodiments depicted. For the embodiments not explicitly shown herein, including those that do not have any slot aspect, their specifics are comprised of various selected assortments of elements from a group of elements that includes, but is not limited to:
1) At least one slot aspect; 2) At least one topographic feature; 3) At least one hull step; 4) A V-shaped fore hull portion; 5) And combinations thereof.
Embodiments of the slot-V hull system include, but are not limited to, a number of hull arrangements comprising novel and nonobvious assortments of the above elements. Among these inventive slot-V hull system element assortments are:
1) A primarily V-shaped fore-hull with at least one slot aspect that has the appropriate dimensional constraints, said dimensional constraints to be detailed following; 2) A primarily V-shaped fore-hull with at least one substantially flatter more aftward hull portion, wherein ventilation of said more aftward hull portion is facilitated by at least one topographic feature; 3) A primarily V-shaped fore-hull with at least one hull step, wherein ventilation of the region trailing said step is facilitated by at least one topographic feature; 4) A primarily V-shaped fore-hull with at least one hull step and at least one slot aspect, wherein ventilation of at least one of said step and slot aspect is facilitated by at least one topographic feature; 5) Any of the assortments 1) through 4) above further combined with at least an additional one of the elements 1) through 5) above; 6) And combinations thereof.
[0056] Thus, a number of permutations of the individual elements and element combinations which are not shown fall within the scope of the present invention, and this can be readily understood by consideration of the first hull arrangement 110 . Included in the first hull arrangement 110 are a primarily V-shaped fore hull, two hull steps, two slot aspects, and two pairs of topographic features. From the preceding description, it should be understood that differing assortments of elements than are depicted in FIG. 1 are also easily understood from inspection of FIG. 1 . A first permutation (not shown) that falls within the scope of the present invention would be a hull arrangement in accordance with FIG. 1 , with the exception that rather than two longitudinally separated sets of hull step, slot aspect and pair of topographic features, this alternative embodiment would have one set of a single hull step, a single slot aspect, and one pair of topographic features. Other permutations (not shown) that fall within the scope of the present invention include, but are not limited to, a hull according to FIG. 1 with the alteration(s) that:
1) The aft slot aspect section 124 and the fore slot aspect section 125 are configured as a single continuous slot aspect; 2) The fore (or aft) slot aspect section 125 ( 124 ) is absent; 3) Additional hull steps, slot aspects, or topographic features are also present (such as an addition of a third set of hull step, slot aspect, and topographic features); 4) Fewer hull steps, slot aspects, or topographic features are present (such as a hull arrangement with a single hull step, slot aspect, and pair of topographic features); 5) Differing numbers of topographic features and/or alternative topographic feature designs (also described in the claims) are utilized; and 6) Alternative slot aspect and/or hull step designs are utilized.
[0063] Two exemplary embodiments of alternative topographic feature and/or hull step designs are illustrated in FIGS. 6 and 7 . Though these designs are termed step cross-sections, it should be understood that these design variations are also applicable to the design cross-sections of the topographic features, and that even a single topographic feature or hull step can have more than one cross-sectional design at differing points along its extent. In addition, a hull step can have a differing cross-sectional design than the topographic feature(s) which facilitate its ventilation. As discussed above, the disposition of the topographic features and/or hull steps can be similar to their respective dispositions in FIG. 1 , or can be modified, in part or in whole, to account for additional design considerations. In FIG. 6 , a second step cross-section 610 has a concave second step surface 612 that provides a rounded forward and upper boundary for a second post-step void 614 . One of the additional benefits, relative to the first step cross-section 510 , provided by the second step cross-section 610 is realized when this cross-section is also utilized for the topographic feature that provides ventilation to the second post-step void 614 , as illustrated in FIG. 3 described previously. The additional ventilation benefit is effected by the greater capability of this cross-section, due to a more effective channeling of the atmospheric airflow, to facilitate atmospheric access to the region of the post-step void 614 . As mentioned previously, a step and/or topographic feature with the second step cross-section 610 would also present greater construction complexity and cost. Since the second step included angle 616 is less than 90°, when constructing a hull with this step and/or topographic feature cross-section, it is necessary to either utilize a multi-part mold, or to form the hull in multiple parts and then join them into a single hull structure, either of which would increase hull construction costs. The relative gains and costs of this cross-section would then have to be evaluated for a determination of the appropriate topographic feature cross-section in a particular situation.
[0064] A third step cross-section 710 is an intermediate approach to the easier construction of the first step cross-section 510 and the improved ventilation performance of the second step cross-section 610 . The third step cross-section 710 can be considered a type of composite of the first and second step cross-sections 510 and 610 , respectively. The third step cross-section 710 has a flat, nearly vertical forward third step surface 712 , and a concave upper third step surface 714 which bound a third step void 716 . The third step cross-section 710 provides some of the ease of construction advantages of the first step cross-section 510 by virtue of its near vertical forward third step surface 712 which is inclined at a third step included angle 718 that is at least one or two degrees more than 90° to allow mold relief without using a multi-part mold or a multi-part hull. The ventilating capability of the third step cross-section 710 , when utilized as a topographic feature cross-section, is greater than that of the first step cross-section 510 , when utilized as a topographic feature cross-section, but lesser than that of the second step cross-section 610 , when utilized as a topographic feature cross-section. Analogously, the ease and cost of construction of the third step cross-section 710 , when utilized as a topographic feature cross-section, is also intermediate of those of the first and second step cross-sections, when they are utilized as topographic feature cross-sections. Once again, the relative gains and costs of this cross-section relative to the variety of alternatives will have to be evaluated for a determination of the appropriate topographic feature cross-section in a particular situation.
[0065] A second hull arrangement 810 representing a second embodiment of the present invention is shown in a mixture of overall, perspective, detail, and schematic views in FIGS. 8 through 11 . FIG. 8 shows the underside of the second hull arrangement 810 for a marine vessel which has a number of components in common with the first hull arrangement 110 including the transom 112 , a second hull bottom surface 813 , the right side 114 , the left side (not shown), the right chine 116 , the left chine 118 , the keel 120 , and the bow 122 . Among the cardinal features of the second hull arrangement 810 is a single central slot aspect 812 , and a single central topographic feature 814 . The central slot aspect 812 is a downwardly opening recess in the second hull bottom surface 813 that extends along the vessel's longitudinal center line. At its forward end, in the general vicinity of where the vessel's second hull bottom surface 813 slopes upward to form the underside of the bow 122 , the central slot aspect 812 transitions into a central topographic feature 814 . Dashed circle 9 circumscribes a region that includes the transition from the keel 120 to the forward end of the central topographic feature 814 . The region within dashed circle 9 is shown in expanded detail in FIG. 9 and the detailed description of the central topographic feature 814 follows in the description of FIG. 9 . In terms of the element assortments detailed previously, the second hull arrangement 810 is an embodiment of the present invention that includes both the 1) and 2) assortments of elements, whereas the first hull arrangement 110 is an embodiment of the present invention that includes all of the 1) through 4) assortments of elements. Alternative embodiments of the second hull arrangement 810 , with differing permutations of the element assortments 1) through 4), including all 4 element assortments, can also be beneficial and lie within the scope of the present invention. As depicted in FIG. 8 , the second hull arrangement 810 further includes an optional first slot aspect extension 1210 . The first slot aspect extension 1210 is capable of providing multiple benefits, depending at least in part on its manners of utilization, the characteristics of the vessel it is a part of, and the situations in which and uses for which said vessel is operated. The specific details of the dispositions and applications of the first slot aspect extension are detailed in the description of FIG. 12 , which is an expanded detail view of the area within dashed circle 12 of FIG. 8 . It is important to note that the first slot aspect extension 1210 is optional, i.e. it is not required of the second hull arrangement 810 to also include the first slot aspect extension 1210 . In those cases when the second hull arrangement 810 does not also include the first slot aspect extension 1210 , the transom 112 is the aft end of the second hull arrangement 810 .
[0066] As can be seen in FIG. 9 , the central slot aspect 812 transitions seamlessly from the central topographic feature 814 , although they are distinct in character. The central topographic feature 814 initiates, when moving rearward from the vessel's forwardmost tip, as a flattened spread 910 of the vessel's keel line 120 , and does not begin to recess into the second hull bottom surface 813 until it's width approaches a significant fraction of the width of the central topographic feature 814 . The differences in character that distinguish the central slot aspect 812 and the central topographic feature 814 include, but are not limited to:
1) The central slot aspect 812 is primarily submerged when the vessel is at rest, while a significant portion of the forward extent of the central topographic feature 814 may be (depending, at least in part, on the extent of the load on the second hull arrangement 810 ) above the resting water line; 2) The central slot aspect 812 maintains a relatively constant width and recess depth for the majority of its extent, while the central topographic feature 814 varies in width and depth (from none to approaching the central slot aspect 812 depth) for the majority of its extent; 3) The central slot aspect is at least partially under water, even when the vessel is at a planing attitude (excepting when the vessel leaves the water surface due to waves, for example), while the central topographic feature 814 is almost entirely out of the water when the vessel is at a planing attitude (excepting when the vessel encounters exceptionally high waves and or is landing back on the water); and 4) The central topographic feature 814 primarily serves to influence atmospheric gasses to access the region of the central slot aspect 812 , while the slot aspect 812 itself serves to channel said atmospheric gasses along the length of the second hull bottom surface 813 to provide a ventilating action that eases the vessel's transitioning to an on-plane attitude, as well as improving the vessel's planing performance.
[0071] FIGS. 10 and 11 provide relative dimensional details of the central slot aspect 812 and the central slot aspect 814 , as well as their dispositional relationship. FIG. 10 is a view from below of the hull bottom second hull arrangement 810 , with cut lines 11 (A-F) demonstrating the planes of view of the cross-sections depicted in FIGS. 11 A-F. The views of the cross-sections 11 A-F depicted in FIG. 11 are oriented with the downward direction indicated by arrow 1110 . In FIG. 11A , the FIG. 10 cut line 11 (A) cross-section is seen to cross the second hull arrangement 810 at a point that is forward of the inception of the central topographic feature 814 . In FIG. 11B , the FIG. 10 cut line 11 (B) cross-section is seen to cross the central topographic feature 814 shortly after its inception, when the central topographic feature 814 is a slender flattened area of width 1112 . In FIG. 11C , the FIG. 10 cut line 11 (C) cross-section is seen to cross the central topographic feature 814 where it has reached a width 1114 that is the majority of the width of the central slot aspect 812 , but prior to where the central topographic feature 814 has begun to recess upward into the second hull bottom surface 813 . In FIG. 11D , the FIG. 10 cut line 11 (D) cross-section is seen to cross the central topographic feature 814 where it has reached the width of the central slot aspect 812 , and has begun to recess upward into the second hull bottom surface 813 . At the longitudinal location of FIG. 10 cut line 11 (D), the central topographic feature 814 has a depth R d (D) which is greater than zero but has not yet reached a full recess depth R d (E) of the central slot aspect 812 as shown in FIG. 11E which depicts the FIG. 10 cut line 11 (E) cross-section of the second hull arrangement 810 . In FIG. 11F , the FIG. 10 cut line 11 (F) cross-section is seen to cross the central slot aspect 812 towards the aft end of the second hull arrangement 810 , where the central slot aspect 812 is depicted as having essentially the same width 1114 and a depth R d (F) that is also essentially the same as the recess depth R d (E). The consistency in width and depth at the cut lines 11 (E) and 11 (F) are only one variant among the embodiments of the present invention, and a number of alternative variants are also encompassed. These alternatives can not only vary in either width or depth of the slot aspect, by either decreasing, increasing, or combinations thereof along the longitudinal extent of the central slot aspect 812 , but can also differ in their profile shape, in their total slot aspect length (as depicted in FIGS. 12 and 13 ), as well as being capable of being configured with capabilities of changing their slot aspect's width, depth, cross-sectional profile, length, and even disposition while the vessel is in use (as depicted in FIG. 14 ). While FIGS. 8-11 depict the forwardmost reach of the central topographic feature 814 as terminating short of the foremost tip of the vessel, this is for illustrative purposes only. Alternative variants of the second hull arrangement 810 (not shown) that also fall within the scope of the present invention include variants wherein the central topographic feature 814 extends farther forward along the vessel's keel line 120 even all the way to the vessel's foremost tip 1010 . Additional variants (not shown) of the second hull arrangement 810 include those wherein:
1) The flattened initiating region of the central topographic feature 814 extends farther forward, including as far as the vessel foremost tip 1010 ; 2) The recessed initiating region of the central topographic feature 814 extends farther forward, including as far as the vessel's foremost tip 1010 ; 3) The increasing width region of the central topographic feature 814 extends farther forward, including as far as the vessel's foremost tip 1010 ; and 4) Combinations of 1) through 3) above.
[0076] In addition to the diversity of embodiments described, as well as permutations of the differing elements and element assortments referred to herein that fall within the scope of the slot-V hull system, further variants in the disposition, construction, and dimensions of the slot aspect (not all shown) are also elements of the range of embodiments encompassed by the present invention. Among the manners in which these slot aspect variants are characterizable are as variations in a first cross-section profile. The first cross-section profile being transverse to a recess length, wherein the recess length is a dimension that tracks the path followed by ventilating gasses. The recess length dimension is capable of being linear, curvilinear, continuous, discontinuous, or combinations thereof. A first manner in which these slot aspect variants are characterizable involves the first cross-section profile having at least one attribute selected from a group consisting of:
a) at least one rectilinear side; b) at least one arcuate side; c) at least one substantially continuous change in slope; d) at least one substantially discontinuous change in slope; e) a disposition that is symmetrical about a vertical plane; f) a disposition that is asymmetrical about a vertical plane; g) a disposition that is symmetrical about a horizontal plane; h) a disposition that is asymmetrical about a horizontal plane; i) a disposition that is symmetrical about a diagonal plane; j) a disposition that is asymmetrical about a diagonal plane; k) at least one positive change in slope; l) at least one negative change in slope; m) and combinations thereof.
[0090] A second manner in which these slot aspect variants are characterizable involves the slot aspect recess delineating a cross-section silhouette, wherein the cross-section silhouette is capable of varying along the length of the slot aspect recess and generally includes at least a partial opening in a lower part of said cross-section silhouette. The cross-section silhouette is transverse to the recess length dimension, and at least a portion of the cross-section silhouette generally approximates at least one shape selected from a group consisting of:
a) a rectangle; b) a trapezoid; c) a triangle; d) a polygon having at least five sides; e) an M-shape; f) an ellipsoid; g) an elliptic section; h) a conic section; i) a parabolic section; j) a hyperbolic section; k) an overall shape that is subdivisible into parts of differing types of shapes, these types of shapes including at least one arcuate type of shape selected from a group consisting of the shapes f)-j) immediately above, and at least one non-arcuate type of shape selected from a group consisting of the shapes a)-e) immediately above; l) an overall shape that is subdivisible into parts of repeating types of shapes, these types of shapes selected from a group consisting of the shapes a)-j) immediately above; m) and combinations thereof.
[0104] In addition, embodiments (not all shown) comprising supplementary variants of the slot aspect that are characterizable according to at least one supplementary member that is at least partially disposed within at least a portion of at least one slot are also encompassed by the present invention. These supplementary members are capable of being disposed within any portion of any slot that provides sufficient space for a particular disposition of a specific supplementary member. The supplementary members can have capabilities of being articulated, of passively moving in response to ambient forces or conditions, of actively moving in response to controlled applications of forces or conditions, or combinations thereof. A representative sampling of some, but not all, of these slot aspect supplementary variants are depicted in FIG. 14 and explicated in the corresponding detailed description.
[0105] FIG. 12 is an expanded detail view of the area within dashed circle 12 of FIG. 8 , depicting the first slot aspect appendage 1210 . The first slot aspect appendage 1210 interconnects with the transom 112 and includes a slot aspect extension 1212 that provides an augmentation to the central slot aspect 812 . The first slot aspect appendage 1210 is comprised of a slot aspect appendage housing 1214 which extends aftward from the transom 112 and includes the slot aspect extension 1212 in its lower portion. In the case of the first slot aspect appendage 1210 as depicted, the slot aspect extension 1212 continues aftward the general form of the central slot aspect 812 in so far as a first appendage recess 1216 formed into the underside of the first slot aspect appendage 1212 has substantially the same longitudinally-transverse cross-section as does the central slot aspect 812 . Although this particular longitudinally-transverse cross-section does provide significant benefits, it is not the only such slot aspect recess longitudinally-transverse cross-section that can be beneficial, and in certain instances alternative cross-sections can be just as, if not more, beneficial. The first slot aspect extension 1212 can also employ these alternative slot aspect cross-sections, either in correlation to alternative variants of the second hull arrangement 810 comprising alternative slot aspect cross-sections, or in disparity to a particular slot aspect cross-section utilized in the second hull arrangement 810 or alternative variants thereof. These alternative slot aspect cross-sections are also capable of being articulated, time-varying, varying by selective or automatic control, as well as differing in differing portions of a given slot aspect. Selected exemplary cases that illustrate the breadth of variations in slot aspects encompassed by the slot-V hull system are depicted in FIG. 14 and are explicated more fully in the corresponding detailed description of FIG. 14 . A first example of a selectively varying slot aspect cross-section is illustrated in FIG. 12 , which depicts an inclusion of an optional selectively movable slot aspect roof section 1218 . The moveable slot aspect roof section 1218 is shown in a withdrawn position wherein it is fully retracted upward into the slot aspect appendage housing 1214 . A lower outer surface 1220 of the movable slot aspect roof section 1218 forms the recess upper boundary surface of the slot aspect extension 1212 . When in the withdrawn position, this upper boundary surface of the first appendage recess 1216 comprises a generally unchanged aftward continuation of the central slot aspect 812 . The movable slot aspect roof section 1218 is capable of pivoting downward about its forward edge 1222 , and when so pivoted downward the cross-section of the first appendage recess 1216 has a progressively diminishing height when moving aftward along the slot aspect extension 1212 .
[0106] Depending on the circumstances of use and the vessel wherein utilized, the aftward continuation of the slot aspect, as well as its capability of selectively altering its cross-section, can provide additional benefits such as an anti-blow-over effect. The blow-over effect can occur if a vessel, when launching off a particularly large and steep wavefront for example, achieves such a steep attitude relative to its direction of motion that the air impacting its underside is capable of flipping the vessel over. Blow-overs are potentially catastrophic events that can destroy a vessel and imperil the welfare of any occupants of the vessel. The slot aspect extension 1212 , in providing an additional surface area that extends aftward beyond the transom 112 for the airflow to impact, will tend to counter the impact of the airflow on the forward portions of the vessel, and thereby mitigate the tendency to flip. The slot aspect extension 1212 is capable of mitigating the tendency to flip in at least two manners. The first manner is by providing an aftward extending surface that, when impacted by airflow or waterflow, will push upward at the stern of the vessel, and hence work against the upward airflow lift at the bow of the vessel that will tend to rotate the vessel downward at the stern. In the potential blowover situation being discussed, the forces acting on the vessel are decomposable into lift acting in the vertical direction, and drag acting opposite the primary direction of motion which is chiefly horizontal. The bow-lifting rotation that presents a risk of blowover also results in induced drag on the slot aspect extension 1212 and the lower surfaces of the slot aspect appendage 1210 . The second manner in which the blowover risk is mitigated is due to the slot aspect extension 1210 producing increased drag acting on the lower aftward portions of the vessel, which at least partially counters the blowover-impelling torques that are acting primarily on the fore portions of the vessel. A significant number of vessels employing the slot-V hull system will have centers of mass that are disposed substantially more aftward than the longitudinal center of the vessel due to the performance and other advantages such a configuration provides. This configuration does, though, increase the potential for blowover because a greater part of the vessel's hull will be disposed forward of the center of mass than aftward, and when the vessel is at an attitude that presents a risk of blowover the airflow impacting on the portion of the hull's underside that is disposed forward of the center of mass will tend to contribute to bringing about blowover. Here too the slot aspect appendage 1210 can provide a further mitigating effect by its greater likelihood of impacting the water's surface than the likelihood of the vessel's transom impacting the water's surface when the vessel is at risk of blowover. Since the dynamic pressure of water is over 800 times greater than that of air, the slot aspect appendage 1210 will not require very much contact with the water surface in order to produce a substantial countering effect to the aerodynamic forces that have the potential to cause blowover. Due to the slot aspect extension 1212 continuation of the ventilating effect of the central slot aspect 812 , the first slot aspect appendage 1210 will produce less drag than a simple hull undersurface extension would, and hence the first slot aspect appendage 1210 can provide the anti-blow-over effect with lesser detrimental consequences than would a hull appendage that does not include a slot aspect. Slot aspect appendages according to the present invention are capable of providing a number of benefits, including the anti-blow-over effect. Among these beneficial capabilities are:
a) Anti-blow-over effect; b) Anti-porpoising effect; c) Trim control augmentation; d) Center-of-lift disposition control augmentation; and e) Improved lateral stability in rough water.
[0112] A vessel is said to be porpoising when, as it progresses across the water, it tends to execute a continuing series of alternating positive and negative pitch rotations. Depending on a vessel's characteristics, environmental conditions, and operating parameters, a vessel's susceptibility to porpoising can be difficult to control, and, once porpoising has initiated, it is capable of being self-propagating. As is readily apparent, porpoising is capable of greatly compromising the vessel's performance, and can be uncomfortable for the vessel's occupants. Slot aspect extensions such as slot aspect extension 1212 are capable of providing the anti-porpoising effect in a similar manner to the previously described second manner of mitigating blowovers, by reducing the vessel's potential for porpoising by decreasing the amplitude of the lifting of the bow as it rebounds from the water. Since one major hazard of porpoising is its potential for self-propagation, the present invention's stabilizing counter effect during pitch oscillation can dampen or even eliminate continuation of the oscillation.
[0113] Slot aspect extensions are capable of providing trim control augmentation by functioning analogously to trim tabs, primarily to influence the vessel's pitch attitude, although certain embodiments of the present invention can utilize a plurality of slot aspect extensions or multipart slot aspect extensions to also influence the vessel's yaw and/or roll attitudes. The means by which a slot aspect extension influences any of a vessel's pitch and/or yaw and/or roll attitudes are similar to conventional trim tabs' operation and as such are readily apparent to those of ordinary skill in marine vessel construction and operation. The manner in which slot aspect extensions are able to operate analogously to trim tabs involves slot aspect extension variants being constructed with capabilities of being movable, including while the vessel is in operation, so that the slot aspect extension's aerodynamic and hydrodynamic effects on the vessel are selectively variable. When at least a portion of a particular slot aspect extension embodiment is capable of varying its relative vertical position, either by translation, rotation, or both, that particular embodiment is capable of influencing a vessel's pitch attitude. For example, the slot aspect extension 1212 with the inclusion of the selectively movable slot aspect roof section 1218 is such a slot aspect extension embodiment that is capable of augmenting a vessel's pitch trim control.
[0114] When a particular slot aspect extension embodiment, which may involve multiple individual slot aspect extensions, is capable of varying a relative vertical disposition of at least a first portion of at least one slot aspect extension, either by translation, rotation, or both, so that the first portion has a different vertical disposition than the vertical disposition of at least a second portion of that slot aspect extension embodiment, and these first and second slot aspect extension portions have differing relative lateral dispositions, then that particular embodiment is capable of influencing a vessel's pitch and/or yaw and/or roll attitudes. The slot aspect extension 1212 with the inclusion of a longitudinally subdivided variant of the selectively movable slot aspect roof section 1218 is such a slot aspect extension embodiment that is capable of influencing a vessel's pitch and/or yaw and/or roll attitudes. A longitudinally subdivided variant of the selectively movable slot aspect roof section 1218 is divided along a longitudinal plane 1224 so that a left side of the selectively movable slot aspect roof section 1218 is capable of altering its inclination by pivoting about the forward edge 1222 separately from the inclination of the right side of the selectively moveable slot aspect roof section 1218 . This slot aspect extension embodiment is capable of providing limited degrees of pitch and/or yaw and/or roll attitude control, but a related slot aspect extension embodiment (not shown) with a pair of slot aspect extensions 1212 , each disposed a selected distance towards each of the vessel's sides from the vessel's longitudinal central plane, and each including a selectively movable slot aspect roof section 1218 , is capable of providing greater degrees of control. A slot aspect appendage side wall 1226 , in addition to contributing to the structural integrity of the slot aspect appendage 1210 , is also capable of providing a degree of stabilizing effect when the vessel assumes attitudes that present potential risks of control loss. One such scenario would be when the vessel is airborne, such as when launching off of a large wave, and the vessel encounters significant side winds or is impelled upward at a disposition that is angled relative to its primary direction of motion. In these cases, the fluid-dynamic effects that impact the vessel in manners that are not congruent with its intended direction of travel could turn or roll it so that when it next meets the water the vessel is in an attitude that presents potentially significant risks of control loss, or even damage. The slot aspect appendage side walls 1226 can help to mitigate this risk by providing a form of air and/or water rudder effect, that would tend to keep the vessel within the range of safe attitudes, relative to its primary direction of travel, similar to how the tail on an airplane works. Additional slot aspect extension variants, including those that are capable of providing degrees of pitch and/or yaw and/or roll trim control are shown in FIG. 14A -N and delineated in the following corresponding portions of this detailed description.
[0115] FIG. 13 depicts a first selectively deployable slot aspect appendage 1310 , in a first extended disposition. The first selectively deployable slot aspect appendage 1310 comprises a deployable slot aspect appendage housing 1312 , the lower extent of which is effectively comparable to the lower extent of the first slot aspect appendage 1210 , and accordingly also includes the slot aspect extension 1212 , the first appendage recess 1216 , and can also include the optional first moveable slot aspect roof section 1218 . A salient distinguishing feature of the selectively deployable slot aspect appendage 1310 is its capability of assuming a range of dispositions by pivoting about a rotational axis 1314 which is disposed parallel to the transom 112 in a generally horizontal disposition. A pivot assembly 1316 rotatably interrelates the selectively deployable slot aspect appendage 1310 with the transom 112 so that the selectively deployable slot aspect appendage 1310 is capable of pivoting about the rotational axis 1314 . An actuator 1318 interconnects the selectively deployable slot aspect appendage 1310 with the transom 112 at an actuator linkage 1320 that comprises a mechanism for selectively enacting pivoting about the rotational axis 1314 . The selectively deployable slot aspect appendage 1310 is capable of being disposed at inclinations that effectively extend the central slot aspect 812 so that the first appendage recess 1216 is capable of being disposed at a range of inclination angles relative to the transom 112 . The range of first appendage recess 1216 dispositional inclination angles is delimited by the constraints on the range of motion available to the selectively deployable slot aspect appendage 1310 . The selectively deployable slot aspect appendage 1310 is capable of rotating upward about the rotational axis 1314 until an upper margin 1322 meets the transom 112 , and is further capable of rotating downward to dispositional angles wherein the lower outer surface 1220 angles downward, relative to the general inclination of the upper surface of the recess formed into the central slot aspect 812 , as the lower outer surface 1220 extends aftward from the rotational axis 1314 . Beyond the multiplicity of benefits during standard operations that are realizable with the selectively deployable slot aspect appendage 1310 , its capability of being disposed at a downward inclination as it extends aftward can also be utilized to provide an additional anti-blowover action, by the actuator disposing the aft end of the selectively deployable slot aspect appendage 1310 at a substantial downward inclination when the vessel is at risk of blowover. When disposed thus downward, the selectively deployable slot aspect appendage 1310 works as a water and/or air deflector that would tend to raise the aft end of the vessel and thereby counter any vessel rotational motion that presents a risk of blowover. The selectively deployable slot aspect appendage 1310 is also capable of incorporating the selectively moveable slot aspect roof section 1218 and thereby provide a vessel with capabilities of effecting a substantially greater range of slot aspect appendage recess roof dispositions. Whereas, in principle, the specific manners in which the selectively deployable slot aspect appendage 1310 is configured, in how its movement is effected, in what types or extents of motion it is capable of, or in how that motion is actuated or controlled are all capable of being accomplished in widely varying ways, in practice a number of vessel design considerations will often entail that certain options are preferable (for example, constructing a vessel of relatively small size will impose limits on the sum weight of a particular realization of a selectively deployable slot aspect appendage embodiment). These design considerations do not, however, limit the multiplicity of manners of realizing a selectively deployable slot aspect appendage that are encompassed by the scope of the present invention, but rather only limit the practical options that are well suited for specific vessels. Moreover, slot aspect appendages such as described above are also capable of being arranged with a detachable capability, so that a vessel according to the present invention is capable of embarking on one type of voyage, in one set of conditions, utilizing a particular slot aspect appendage that is well suited for those circumstances, and on another voyage in a differing set of conditions that vessel can embark without a slot aspect appendage when such an arrangement is better suited for those differing circumstances.
[0116] FIG. 14A -N depict schematic cross-sections of a sampling of the range of varieties of slot aspect recess realizations according to the slot-V hull system. The orientation of the points of view FIGS. 14 A-N are cross-sections taken transverse to the vessel's longitudinal axis, facing the fore end of the vessel when it is in an upright disposition, with the vessel's left side to the left of the view depicted in FIGS. 14 A-N. In all of FIGS. 14 A-N the hull bottom surface 113 is seen to continue outward and upward at a moderate dead rise angle to the right and the left. The dead rise angle as shown is merely depicted for illustrative purposes, and is not limiting of the range of dead rise angles, both steeper and shallower, with which the present invention is capable of being realized. Moreover, a specific slot aspect can comprise more than one slot aspect recess configuration at differing longitudinal positions. As will be described subsequently, a single slot aspect recess configuration may also be capable of altering its configuration, even while the vessel is in operation in certain embodiments. Additionally, although the slot aspect recess varieties as shown in FIGS. 14 A-N imply that the vessel is arranged with a single slot aspect, this is only for purposes of clarity. It is envisioned that certain embodiments of the present invention will comprise more than one slot aspect, separated longitudinally and/or laterally, and that at least some portions of these slot aspects are capable of having differing slot aspect recess configurations than other portions of the same or a separate slot aspect. The present invention encompasses nearly any permutation and/or combination of these slot aspect recess configurations, as well as combinations of elements from one schematic slot aspect configuration mingled with elements of one or more other slot aspect recess configurations. The various slot aspect recess configurations can comprise varying cross-section profiles and silhouettes, varying manners of altering the slot aspect recess cross-section profiles and silhouettes, as well as varying manners of effecting said altering of the slot aspect recess profiles and silhouettes.
[0117] Of the range of slot aspect recess cross-sections described herein, many will often be suitable for one set of marine conditions, or vessel characteristics, or projected manners of vessel operation, but not for others, and as described previously a multitude of design considerations will be involved in determining the appropriate selection for a particular vessel, conditions, and projected operational objectives. A first slot aspect recess cross-section 1410 depicted in FIG. 14A has a cross-section profile with the general shape of an open bottomed rectangle. A second slot aspect recess cross-section 1412 depicted in FIG. 14B has a cross-section profile generally similar to a flattened M-shape, wherein the outside legs of the “M-shape” are angled inward from bottom to top. A third slot aspect recess cross-section 1414 depicted in FIG. 14C has a laterally asymmetrical shape with a sloped planar slot aspect recess roof 1416 , wherein a left slot aspect recess wall 1418 is of lesser height than a right slot aspect recess wall 1420 . Such a laterally asymmetrical third slot aspect recess cross-section 1414 can be of benefit, for example, when the vessel is expected to operate in an environment which will present consistently asymmetrical conditions, such as a river ferry that will consistently be required to navigate conditions that differ greatly during one leg of its round trip from the conditions it navigates during the return leg of its round trip. A fourth slot aspect recess cross-section 1422 depicted in FIG. 14D has a bifurcated cross-section profile comprised of a pair of laterally asymmetrical insets 1424 R and 1424 L positioned towards the right and left sides, respectively, of the fourth slot aspect recess cross-section 1422 . The insets 1424 R and 1424 L are essentially mirror images of each other, laterally separated by a longitudinal inset dam 1426 that depends downwardly from the upper boundary of the fourth slot aspect recess cross-section 1422 . The longitudinal inset dam 1426 is disposed in a generally longitudinally central position, and in combination with the mirror image dispositions of the insets 1424 R and 1424 L, the fourth slot aspect recess cross-section 1422 provides a generally laterally symmetrical overall arrangement. As shown in FIG. 14D , the longitudinal inset dam 1426 has a not insignificant width that enables the longitudinal inset dam 1426 to both laterally divide as well as separate the insets 1424 R and 1424 L. The width of the longitudinal inset dam 1426 is capable of varying, with differing widths being capable of providing gradations in how the two insets' aerodynamic and hydrodynamic effects vary between operating in close unison when the width is small, up to operating in effective independence when the width is relatively great. An outer inset boundary wall 1428 slopes inward from top to bottom towards the longitudinal central plane in FIG. 14D , but it can also be sloped at varying inclinations (not shown) including vertical and outwardly sloping. Outside of the performance issues that influence the choice of inclination of outer inset boundary wall 1428 , ease of construction can also influence the choice of inclination, since when the outer inset boundary wall 1428 is sloped inward from top to bottom, it is unlikely to be possible to construct such a hull arrangement with a single mold due to an inability to achieve mold relief with an inward slope as shown. It should also be noted that an inset upper boundary wall 1430 is also sloped at an angle relative to the horizontal. In the embodiment depicted in FIG. 14D , the inset upper boundary wall slopes downward in the outward direction. This slope can also be varied (not shown) both in degree of inclination as well as being capable of alternatively being horizontal or sloped upward towards the outward direction, the choice among these options again being influenced by various design, construction, and operational parameters.
[0118] A fifth slot aspect recess cross-section 1432 depicted in FIG. 14E has an overall outline similar to the first slot aspect recess cross-section 1410 with the addition of three slot aspect recess partitions 1434 . The slot aspect recess partitions 1434 are shown in FIG. 14E as depending vertically downward from the roof of the slot aspect recess, although the inclination of these slot aspect recess partitions is capable of varying (not shown). Additionally, the total number of the slot aspect recess partitions, their lateral dispositions relative to the boundaries of the fifth slot aspect recess cross-section 1432 , and the extent of their downward reach (including beyond the furthest downward reach of the slot aspect recess), relative to the depth of the fifth slot aspect recess cross-section 1432 , are also capable of varying (not shown) depending of the aforementioned types of design criteria. The slot aspect recess partitions 1434 are distinguished from the longitudinal inset dam 1426 of the forth slot aspect recess cross-section 1422 by their distinctly thinner widths. Because the slot aspect recess partitions 1434 have relatively limited widths they are capable of providing at least a partial subdividing effect to the fifth slot aspect recess cross-section 1432 , but are not capable of providing a substantial separating effect. The slot aspect recess partitions 1434 , are also capable of being combined with any alternative overall outline such as the overall outline of the second slot aspect recess cross-section 1412 (not shown), for example. The slot aspect recess partitions 1434 can also be inclined at angles other than the vertical (not shown), including horizontal (wherein they would be interconnected with the outer boundary walls of the fifth slot aspect recess cross-section 1432 ) and various diagonal angles.
[0119] The manners in which elements of the various slot aspect recess cross-sections are capable of being utilized also encompasses degrees of articulation, as well as various movement capabilities. In general, a constituent and/or property of a slot aspect that is capable of providing these articulation and movement capabilities are termed, when referred to collectively, as a quality of a slot aspect or a slot aspect extension, where appropriate, in the specification and claims contained herein, although particular individual parts and/or facets of an embodiment may also be referred to by other terms when useful for purposes of distinction. A sixth slot aspect recess cross-section 1436 depicted in FIG. 14F shows a first slot aspect moveable element 1438 . The first slot aspect moveable element 1438 functions as a moveable slot aspect recess upper boundary wall, translating vertically between an uppermost boundary wall position 1440 and the lowermost reach of the sixth slot aspect recess cross-section 1436 . The means of effecting or controlling the motion of the slot aspect moveable element 1438 are not constrained in principle, and are constrained in practice only by practicality and design considerations. These means of effecting or controlling motion can be passive or active, powered or ambiently impelled, and selectively, autonomously, or automatically instigated. Passive means will operate without a specifically directed input, such as in response to a given sensed vessel speed, and active means will operate in response to an expressly directed input, such as a user selecting a given first slot aspect moveable element 1438 disposition according to an anticipated vessel speed. Powered means will utilize at least one power source, such as an electric motor, to impel the vertical translation, while ambient means will utilize ambient conditions, such as the surface pressure upon a portion of the vessel or inertial forces resulting from turning the vessel, to impel the vertical translation. Selective means of effecting the vertical translation will operate in response to a determination by a human or other control system, autonomous means will operate without a determination, and automatic means will operate in response to a predetermination. These various means of effecting or controlling the motion of the moveable slot aspect recess moveable element 1438 , and combinations thereof, also apply to the other slot aspect recess moveable elements described herein. The scope of the present invention also encompasses alternative slot aspect recess cross-sections wherein the moveable element is a portion of the slot aspect overall outline that differs from the upper boundary wall as depicted in FIG. 14E , such as an alternative variant of the third slot aspect recess cross-section 1414 wherein the right slot aspect recess wall 1420 is horizontally moveable.
[0120] Among the slot aspect moveable elements' various movement capabilities are overall translations, such as in the case of the first slot aspect moveable element 1438 ; rotations about various rotational axes, such as an alternative variant of the sixth slot aspect recess cross-section 1436 (not shown) wherein the first slot aspect moveable element 1438 is alternatively capable of rotating about at least one of its lateral endpoints where it meets a side boundary wall of the slot aspect recess; and combinations thereof. The location of a rotational axis is not required to be disposed at an endpoint of a particular slot aspect moveable element, but can also be disposed at an intermediate point of the slot aspect moveable element, and a particular slot aspect moveable element is also capable of being rotatable about more than one rotational axis. Included among the slot aspect moveable elements' various degrees of articulation are alternative variants of the representative sample of slot aspect recess cross-sections explicitly depicted herein, wherein these alternative variants involve at least one constituent of these cross-sections including at least one point of articulation. The types of articulation are not restricted in principle, other than the necessity of ensuring that any point of articulation maintain a relatively watertight interconnection if that point of articulation is potentially exposed to water, and said types of articulation are capable of involving relative translations, relative rotations, or combinations thereof. An example of an alternative slot aspect recess cross-section variant with an articulated slot aspect moveable element (not shown) is the second slot aspect recess cross-section 1412 wherein the central juncture between the downwardly depending upper boundary sections 1442 becomes a pivotal interconnection so that the relative vertical position of the pivotable central juncture has a variable elevation capability (which will also involve either the downwardly depending upper boundary sections 1442 being capable of varying their length and their angle of juncture with outer boundary walls 1444 , and/or the outer boundary walls 1444 being capable of rotating about their junctures with the hull bottom surface 113 ). These alternative slot aspect cross-section variants are also capable of including articulated junctures within a slot aspect constituent element at dispositions where the slot aspect constituent element had been unarticulated in other embodiments. Representative examples of the addition of articulated junctures and/or additional movement capabilities include alternative variants of the fifth slot aspect recess cross-section 1434 that incorporate various forms of the above described movement and/or articulation capabilities are:
1. A first alternative variant of the fifth slot aspect recess cross-section 1432 wherein at least one of the slot aspect recess partitions 1434 includes a pivoting juncture disposed at its vertical midpoint, so that the lower portion of the then articulated slot aspect recess partition 1434 is thus capable of pivoting to the left or right; 2. A second alternative variant of the fifth slot aspect recess cross-section 1432 wherein at least one of the slot aspect recess partitions 1434 is capable of translating vertically (either by being capable of altering its overall length or by passing up or down through a slot aspect recess upper boundary wall akin to a selectively deployable keel plate); 3. A third alternative variant of the fifth slot aspect recess cross-section 1432 wherein the relative lateral disposition of at least one slot aspect recess partition 1434 is capable of being varied by translating horizontally; 4. A fourth alternative variant of the fifth slot aspect recess cross-section 1432 wherein at least two adjacent slot aspect recess partitions 1434 can pivot about their junctures with the upper boundary wall of the slot aspect recess so that they can meet at their lowest extents and form a triangular shape; and 5. Combinations thereof.
[0126] A seventh slot aspect recess cross-section 1446 depicted in FIG. 14G shows second slot aspect recess moveable elements 1448 L and 1448 R disposed on the left and right sides of the slot aspect recess cross-section, respectively. Each of the second slot aspect recess moveable elements 1448 L and 1448 R are capable of assuming a plurality of vertical dispositions, ranging between a lowest disposition corresponding to the depicted disposition of second slot aspect recess moveable element 1448 L and a highest disposition corresponding to the depicted disposition of second slot aspect recess moveable element 1448 R. The relative dispositions of the second slot aspect recess moveable elements 1448 L and 1448 R, respectively, can be controlled to operate independently, or can be interrelated in various ways such as upward translation of one movable element being associated with downward translation of the other.
[0127] An eighth slot aspect recess cross-section 1450 depicted in FIG. 14H comprises a slot aspect recess with an arcuate profile. A ninth slot aspect recess cross-section 1452 depicted in FIG. 14I comprises a bifurcated cross-section profile analogous to the fourth slot aspect recess cross-section 1422 , with the discrepancy that left and right laterally asymmetrical arcuate insets 1454 L and 1454 R, respectively, are delineated by arcuate boundaries rather than the polygonal boundaries of the left and right laterally asymmetrical insets 1424 R and 1424 L. A tenth slot aspect recess cross-section 1456 depicted in FIG. 14J comprises an arcuate profile with a resiliently deformable boundary 1458 . The resiliently deformable boundary 1458 , when not forcibly deformed, has a resting profile comparable to the eighth slot aspect recess cross-section 1450 . A first recess boundary deforming element 1460 is schematically depicted in FIG. 14J as having a generally circular cross-section and is capable of moving both horizontally and vertically. The cross-sectional shape, particular disposition, directions of motion capabilities, and relative size of the first recess boundary deforming element 1460 are not limiting and are selected only for purposes of clarity of description. As the first recess boundary deforming element 1460 is translated downward, it presses on the resiliently deformable boundary 1458 and forces downward the portion of the resiliently deformable boundary 1458 immediately below the first recess boundary deforming element 1460 to thereby modify the profile of the recess bounded by the tenth slot aspect recess cross-section 1456 . Alternative variants (not shown) of the tenth slot aspect recess cross-section 1456 can utilize variations in the size and/or shape and/or manners of motion of the first recess boundary deforming element 1460 as well as variations in the flexibility and/or size of the resiliently deformable boundary 1458 to provide additional manners of deforming the recess profile. Additionally, alternative variants of the first recess boundary deforming element 1460 can also operate through inflation, whereby alterations in its size are capable of effecting the deformation of the resiliently deformable boundary 1458 .
[0128] An eleventh slot aspect recess cross-section 1462 depicted in FIG. 14K also comprises the resiliently deformable boundary 1458 , with an alternative operative manner of effecting deformation of said resiliently deformable boundary 1458 . As depicted in FIG. 14K , a plurality of second recess boundary deforming elements 1464 are arrayed side by side across the width of the eleventh slot aspect recess cross-section 1462 . While this arrangement of second recess boundary deforming elements 1464 is representative of the eleventh slot aspect recess cross-section 1462 , alternative variants of this cross-section can comprise differing numbers of and differing individual or collective dispositions of the second recess boundary deforming elements 1464 . In the eleventh slot aspect recess cross-section 1462 , the second recess boundary deforming elements 1464 can have capabilities of varying their vertical positions either independently, or in coordinated groupings and can thereby provide a more finely detailed degree of recess cross-section control than is available for the tenth slot aspect recess cross-section 1456 . The resiliently deformable boundary 1458 can be constructed with a natural undeformed position that affords a maximum recess cross-sectional area so that the dispositions of the second recess boundary deforming elements 1464 , by their relative vertical positions, determine the operative disposition of the resiliently deformable boundary 1458 . Alternatively, the resiliently deformable boundary 1458 can be interconnected with the second recess boundary deforming elements 1464 so that their upward and downward movement will also move the portion of the resiliently deformable boundary 1458 that is interconnected with those second recess boundary deforming elements 1464 that are moving. A still further alternative variant of the eleventh eighth slot aspect recess cross-section 1462 comprises alternative variants (not shown) of the second recess boundary deforming elements 1464 , including variants wherein the second recess boundary deforming elements 1464 are shaped differently than the oval shape depicted in FIG. 14K , wherein the variants of the second recess boundary deforming elements 1464 are capable of altering their shape or size, such as by inflation, and variants wherein the second recess boundary deforming elements 1464 are caused to move (including horizontally, vertically, or diagonally) by a variety of means. These means encompass various mechanical and/or electrical mechanisms, and can be actuated by mechanical, electromagnetic, pneumatic, hydraulic, and other well understood manners of generating actuating forces.
[0129] A twelfth slot aspect recess cross-section 1466 depicted in FIG. 14L involves a centrally pivoting slot aspect recess upper boundary element 1468 that is capable of pivoting between end positions 1468 A and 1468 B. The centrally pivoting slot aspect recess upper boundary element 1468 pivoting is capable of providing an enhanced degree of turning and/or roll control, among other capabilities, both by providing greater keel-plate-like effects and by operatively assuming a laterally asymmetrical profile (such as when in the end position 1468 A) that is adapted for providing the vessel with this greater keel-plate-like effect in a manner that is responsive to the turn being effected. When the centrally pivoting slot aspect recess upper boundary element 1468 is in end position 1468 A, the slot aspect recess presents a significantly greater depth on its right side than on its left side, which is useful when the vessel is effecting a right turn because the vessel's centripetal acceleration will tend to push the vessel to the left and hence the water surface will tend to cross the slot aspect recess in a left to right direction. The greater right side depth of the slot aspect recess when the centrally pivoting slot aspect recess upper boundary element 1468 is in position 1468 A will present greater resistance to this left to right motion of the water, and hence will provide the vessel greater “traction” on the water to effect the turn and thereby produce the greater keel-plate-like effect. Controlling and actuating the pivoting of the centrally pivoting slot aspect recess upper boundary element 1468 (in addition to the previously described means of controlling and/or effecting movement of a portion of a slot aspect) can be configured to be inherently responsive to the vessel's motion itself, and changes thereof. An example of an inherently responsive means (not shown) can involve an inertial mass (such as spring-loaded counterweight) capable of responding to centripetal acceleration caused by turning the vessel at speed. The inertial mass would then move in response to the centripetal acceleration, and in so doing would actuate the pivoting of the centrally pivoting slot aspect recess upper boundary element 1468 . Such an apparatus could operate, when the vessel is making the right turn described above, by said inertial mass sliding to the left in response to the vessel's centripetal acceleration, said leftward inertial mass motion pressing on a device such as a mechanical linkage or a compressible bladder to impel the centrally pivoting slot aspect recess upper boundary element 1468 into end position 1468 A. Even an apparatus as simple as a weight sliding laterally on a track laying on top of the centrally pivoting slot aspect recess upper boundary element 1468 and running transverse to the longitudinal axis of the vessel can cause the shifting between the end positions 1468 A and 1468 B. The uneven weight distribution, engendered by the weight being impelled towards an end of the lateral track during a turn, causes the more heavily weighted side of the centrally pivoting slot aspect recess upper boundary element 1468 to pivot downwards thereby effecting the desired laterally asymmetrical slot aspect recess cross-section in automatic response to the vessel's turning action. A still more basic spring-loaded alternative embodiment (not shown) of the twelfth slot aspect recess cross-section 1466 is capable of having its slot aspect recess cross-section automatically altered by forces inherently involved in turning the vessel by responding to a lateral asymmetry in the surface pressure within the slot aspect recess during a turn. In a right turn, for example, the vessel's centripetal acceleration will impel the vessel to the left, and hence cause the right side of the slot aspect recess to be subject to a greater surface pressure than the left side is subject to. At least one spring (or other types of forcibly compressible rebounding members such as an elastic bladder of gas) is selected to provide an appropriate level of resistance to upward movement of either side of the centrally pivoting slot aspect recess upper boundary element 1468 . The springs are utilized so that when the vessel is traveling relatively straight the centrally pivoting slot aspect recess upper boundary element 1468 is held relatively horizontal, and when the vessel is executing a sufficiently forceful turn the lateral pressure imbalance within the slot aspect recess will pivot upward the interior turn side of the centrally pivoting slot aspect recess upper boundary element 1468 and hence provide a higher slot aspect recess right side 1470 which will thereby facilitate the vessel's turning performance.
[0130] A thirteenth slot aspect recess cross-section 1472 depicted in FIG. 14M combines certain capabilities of the fifth slot aspect recess cross-section 1432 and certain capabilities of the sixth slot aspect recess cross-section 1436 . The thirteenth slot aspect recess cross-section 1472 utilizes the slot aspect recess partitions 1434 to provide lateral subdivisions of the slot aspect recess, and disposes a plurality of third slot aspect recess movable elements 1474 (similar to laterally smaller versions of the second slot aspect recess movable element 1448 ) within the spaces between the slot aspect recess partitions 1434 . The third slot aspect recess movable elements 1474 retain both the vertical movement capabilities of the second slot aspect recess moveable elements 1448 and the capabilities of moving independently of and/or in coordination with each other. A fourteenth slot aspect recess cross-section 1476 depicted in FIG. 14N provides capabilities of effecting additional manners of slot aspect recess cross-section alterations. A laterally movable slot aspect recess element 1478 has capacities of being disposed in various positions between, and including, the leftmost and rightmost positions within the slot aspect recess. While shown as a trapezoidal shaped cross-section, the laterally movable slot aspect recess element 1478 , can also be constructed of differing shapes, as well as being capable of altering its shape in various well known manners. The fourteenth slot aspect recess cross-section 1476 is shown with a single laterally movable slot aspect recess element 1478 only for purposes of clarity of illustration and alternative variants of the fourteenth slot aspect recess cross-section 1476 (not shown) are capable of including a plurality of the laterally movable slot aspect recess elements 1478 , at least some of which can also be capable of altering their shape. The various manners of controlling and/or effecting movement described previously in regard to other movable constituents of the present invention also apply to the constituents of the thirteenth slot aspect recess cross-section 1472 and the fourteenth slot aspect recess cross-section 1476 as well also.
[0131] The above described panoply of slot aspect recess cross-sections and elements thereof are also capable of being combined and/or intermixed in varied permutations to comprise alternative embodiments (not shown) of the present invention. Additionally, due to the interrelated associations between the topographic features and the slot aspects in a number of embodiments, many of the range of slot aspect recess cross-sections as well as the elements thereof are also capable of comprising attributes of the topographic features of alternative embodiments (not shown) of the slot-V hull system. Included among the types of interrelated associations are those wherein at least one of the topographic features and at least one of the slot aspects that comprise an embodiment are continuously intermeshed without an absolutely distinct demarcation between them. Such a case is exemplary of, but not a requirement for, an extension of the varieties of realizing a slot aspect recess cross-section to manners of realizing, operating, or designing topographic features of alternative embodiments of the present invention. In general, when a distinction between the nature of a topographic feature and a slot aspect is germane, they can usually be distinguished by their differing manners of optimal operation. Topographic features usually dispose at least a portion of their extent primarily out of the water and interacting primarily with a gas that is capable of being utilized for ventilation of a portion of the underside of a marine vessel hull. By contrast, at least one significant portion of at least one slot aspect is usually disposed so as to primarily interact with the water and/or a water/gas “spray” mixture. When functioning as intended, slot aspects are generally not primarily interacting with only a gas.
[0132] The slot-V hull system is comprised of a range of both methods and apparatuses which are capable of providing the functional capacities described herein. Regularly, these methods are characterizable in at least one of three ways:
1) As a method of providing a described apparatus for various functional uses; 2) As a method of operating a described apparatus for various purposes; and 3) As a method of performing various functions, in and of themselves, that are analogous to differing groups of functions that certain of the apparatuses described herein are also capable of performing when said apparatuses are operating.
These methods are often well described by the claim(s) that define them. The detailed means of implementation, if not entirely evident on the basis of a particular method claim or group of method claims, is evident when the claim is read in light of an apparatus described herein that is capable of providing, operating as, or performing the specific method claimed.
[0136] In view of the above, it will be seen that the various objects and features of the invention are achieved and other advantageous results obtained. The examples contained herein are merely illustrative and are not intended in a limiting sense. | The present invention comprises systems and methods of utilizing hull arrangements that combine aerodynamic and hydrodynamic effects to provide marine vessels with broader ranges of performance capabilities. The combination hull arrangements variously combine V-hulls, slot aspects, topographic features, and other hull characteristics that enable a vessel to retain the primary performance benefits of conventional V-hulls and achieve assorted improvements. Embodiments of the slot-V hull system employ specifically shaped hull characteristics to influence the manners in which water, air, and air/water spray mixtures interact with the vessel's hull. One principal operative effect can enable a vessel with the slot-V hull system to achieve a planing attitude more rapidly and efficiently than a standard V-hull. | 1 |
FIELD OF THE INVENTION
This invention pertains to the field of compressors used in chillers and/or heat pumps, and in particular, to protecting the compressor by keeping the compressor within its proper operating parameters.
BACKGROUND OF THE INVENTION
Heat pump systems use a refrigerant cycle to transfer heat (or energy) from a relatively cool side to a hotter side. At the cooler side, evaporation of the refrigerant occurs at a relatively low pressure. As a result, liquid is turned into vapor and heat is extracted from a media that can be air, water, brine, or even the ground. The generated vapor flows through one or more compressors where its pressure is raised. After leaving the compressor, the high pressure vapor flows into a condenser where it is turned into a liquid. At this stage, heat is released by the refrigerant into another media that can be air, water, brine, or the ground. The amount of heat released is roughly equal to the amount of heat extracted at the cooler side plus the amount of energy needed to drive the vapor refrigerant from the low pressure side (cool side) to the high pressure side (hotter side).
Because the refrigerant cycle in a heat pump can be reversed, the unit can be used for either heating or cooling. In principle, the refrigerant cycle for the two modes are comparable.
For heat pumps to operate efficiently, an adequate temperature difference must exist between the refrigerant and the medias (air, water, brine, or ground). From an efficiency standpoint, it is desirable that the heat pump deliver more energy (thermal) than it uses (electrical).
The heart of a heat pump or chiller system is the compressor. Each compressor type has an associated compressor map, i.e., an area function of saturated suction temperature and saturated discharge temperature. Manufacturers typically guarantee the reliability of the compressor if the compressor is operated within its compressor map. Unfortunately, compressors can operate outside their compressor map, unbeknownst to the user, until the compressor fails suddenly.
SUMMARY OF THE INVENTION
Briefly stated, a controller monitors the saturated suction temperature and the saturated discharge temperature of a system that includes a compressor operating as part of a chiller and/or heat pump. When the compressor operates outside its compressor map, the controller takes action to ensure the compressor operates only within its compressor map. Such actions include defrosting the compressor coil if the system is in heating mode or unloading the unit.
According to an embodiment of the invention, a method for protecting at least one compressor used in a heat pump or chiller system includes the steps of (a) determining a saturated suction temperature (SST) for the at least one compressor; (b) determining a saturated discharge temperature (SDT) for the at least one compressor; (c)providing first and second limits for the at least one compressor; (d) providing first and second specified performance margins for the at least one compressor wherein the first and second performance margins are related to the first and second limits; (e) determining, based on the first and second limits and the first and second performance margins, whether the at least one compressor is operating in a preferred zone, and if not, performing a subsequent action.
According to an embodiment of the invention, a method for protecting at least one compressor used in a heat pump or chiller system includes the steps of (a) determining a saturated suction temperature (SST) for the at least one compressor; (b) determining a saturated discharge temperature (SDT) for the at least one compressor; (c) providing first and second limits for the at least one compressor; (d) providing first and second specified performance margins for the at least one compressor wherein the first and second performance margins are related to the first and second limits; (e) comparing the SST to a specified temperature, and if the SST is less than the specified temperature, unloading, if present, one compressor from the system, and if the SST is not less than the specified temperature, comparing the SST to a sum of the first limit and the first performance margin; (f) determining, if the SST is not greater than the sum of the first limit and the first performance margin, whether the SST is greater than the first limit; (g) determining, if the SST is greater than the sum of the first limit and the first performance margin, whether frosting of a condenser coil is greater than a specified percentage, and if so, defrosting the coil, and if not, unloading, if present, one compressor from the system; (h) determining, if the SST is not greater than the first limit, whether a rate of change of the SDT is greater than a specified amount, and if not, periodically determining whether the rate of change of the SDT is greater than the specified amount, and if so, determining whether frosting of the coil is greater than the specified percentage, and if so, defrosting the coil, and if not, unloading, if present, one compressor from the system; and (i) determining, if the SST is greater than the first limit and the SST is not greater than the sum of the first limit and the first performance margin, whether the SDT is greater than a difference between the second limit and the second performance margin, and if so, forbidding compressor loading, and if not, allowing compressor loading if necessary.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 shows a typical compressor map.
FIG. 2 shows a simplified schematic of a chiller circuit.
FIG. 3 shows a modified flow chart according to the method of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Although the invention can be applied to any kind of heat pump or chiller, the following explanation focuses mainly on an air to water heat pump.
Referring now to FIG. 1, a typical compressor map shows an operating area within the parameters of SST (saturated suction temperature) and SDT (saturated discharge temperature). The area bounded by the lines is the safe operating area for a given compressor.
Referring to FIG. 2, a condenser 20 is fluidly connected to an evaporator 30 via an electronic expansion valve EXV. Vapor from evaporator 30 travels to a compressor 40 where the vapor is liquefied and pressurized before entering condenser 20 . A transducer 60 , preferably a suction pressure transducer, determines a suction pressure and converts the suction pressure to the saturated suction temperature SST based on the known simple linear relationship between saturated pressure and saturated temperature. A transducer 70 , preferably a discharge pressure transducer, determines a discharge pressure and converts the discharge pressure to the saturated discharge temperature SDT. Thermistors which read the appropriate temperatures directly are optionally used, but are not considered to be as accurate as the preferred pressure transducers. The SST and SDT are read by a controller 18 . Controller 18 can be a microcontroller or CPU, which can be preprogrammed for a specific compressor or optionally programmed for different compressors as necessary.
Referring to FIG. 3, the SST and SDT as read by controller 18 are processed according to the flow chart depicted. The SST is measured every 15 seconds in step 110 . The SST is compared to a given temperature, shown as “X” in step 120 , provided by the compressor manufacturer based on the compressor map for the particular unit being controlled. Values depicted as “limit1”, “limit2”, “Y” (steps 140 , 150 ) and “Z” (steps 160 , 170 ) are also based on the compressor map. For example, for Carrier Corporation model numbers 30RH 17/21/26/33/40/50/60/70/80/90/100/120/140/160/200/240, limit1=68° F., limit2=150° F., X=−4° F.; Y=10° F.; and Z=2° F. Thus, the safe performance margins for these model numbers are limit2−Z=148° F. and limit1+Y=78° F. If the SST is less than or equal to X° F., one compressor is unloaded in step 125 . If the SST is greater than X° F., another check is made to see if the SST is greater than limit1 by a certain amount, “Y”, as shown in step 140 . If yes, coil frosting is checked in step 142 as described in U.S. patent application Ser. No. 09/525,348, filed Mar. 15, 2000 and entitled, METHOD AND SYSTEM FOR DEFROST CONTROL ON REVERSIBLE HEAT PUMPS, incorporated herein by reference. If coil frosting is greater than 75%, the coil is defrosted as shown in step 144 . If coil frosting is less than 75%, one compressor is unloaded as shown in step 146 .
If the SST is not greater than limit1+Y° F. in step 140 , the SST is checked in step 150 to see if the SST is still greater than limit1. If not, the rate of change of the SDT is checked in step 152 to see if it is greater than a specified amount, such as, for example, 1.1° F./min. The exact value depends on the compressor(s) being controlled. If the rate of change is greater than 1.1° F./min, the degree of coil frosting is checked in step 154 . If the rate of change is not greater than 1.1° F./min, the rate of change is checked again in a specified time, shown in FIG. 3 as three minutes. If the degree of coil frosting in step 154 is greater than 75%, the coil is defrosted in step 158 ; otherwise, one compressor is unloaded in step 156 .
If the SST is less than limit1, that is, if the compressor is operating within its normal SST range, the SDT is checked in step 160 to see if it is greater than limit2 minus a safety margin “Z.” If yes, compressor loading is forbidden in step 162 . Otherwise, it is safe to allow compressor loading if necessary as shown in step 170 .
The present invention thus ensures that the compressor operates within the compressor map and thus are covered by the manufacturer's guarantee provisions guaranteeing the compressor's lifespan and reliability.
While the present invention has been described with reference to a particular preferred embodiment and the accompanying drawings, it will be understood by those skilled in the art that the invention is not limited to the preferred embodiment and that various modifications and the like could be made thereto without departing from the scope of the invention as defined in the following claims.
While the present invention has been particularly shown and described with reference to the preferred mode as illustrated in the drawing, it will be understood by one skilled in the art that various changes in detail may be effected therein without departing from the spirit and scope of the invention as defined by the claims. | A controller monitors the saturated suction temperature and the saturated discharge temperature of a system that includes a compressor operating as part of a chiller and/or heat pump. When the compressor operates outside its compressor map, the controller takes action to ensure the compressor operates only within its compressor map. Such actions include defrosting the compressor coil if the system is in heating mode or unloading the unit. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a Continuation-in-Part of and claims benefit to U.S. patent application Ser. No. 11/171,866, entitled “Process and Streaming Server for Encrypting a Data Stream,”, filed Jun. 30, 2005, which is in turn is a continuation of and claims benefit to U.S. patent application Ser. No. 10/109,963, entitled “Process and Streaming Server for Encrypting a Data Stream,”, filed Mar. 29, 2002, which is in turn a continuation of and claims benefit to U.S. patent application Ser. No. 09/436,916, entitled “Process and Streaming Server for Encrypting a Data Stream,” filed Nov. 9, 1999, under 35 U.S.C. §120 and 37 C.F.R. §1.53(b), each of which are incorporated herein by reference.
TECHNICAL FIELD OF THE INVENTION
The present invention provides a process for encrypting a data stream to secure the data stream for single viewing and to protect copyrights of the data stream. Specifically, the invention provides a process for protecting streaming multimedia, entertainment, and communications in an Internet-type transmission. The invention further provides a streaming server component operably connected with a streaming server that interacts with a client system to affect the inventive process.
BACKGROUND OF THE INVENTION
The Internet has provided another means for communication whereby data can be streamed from a server to a client. The client is responsible for displaying the streamed data, preferably streamed media, to a user. The server is responsible for delivering the data stream to the client. The Real Networks and Microsoft solutions send the data stream via a UDP (a connectionless Internet protocol) along with another connection between the client and the server that controls the transmission of the streamed data. The control connection element functions to stop buffer overruns and can adjust the transmission of the stream to compensate for bandwidth latencies. One problem with this arrangement, however, is that the data that are streamed to the client from the server are unprotected and available to anyone on the network. Therefore, there is a need in the art to better protect from interception across a wide area network, such as the Internet. Specifically, the need relates to providing an ability to protect the improper interception and ability to copy streaming data across the Internet. At present, there is no protection mechanism in place to protect copyrighted data.
Once the data has been released by the server and either received by the user or intercepted before being received by the user, there is no way to restrict the re-transmission of such data once it has been released over a network. Even if the data stream has been copyrighted, there is no means to protect or enforce copyright protection of streamed data. The entity owning the copyright and streaming such content realize that there is no control over what is done with such content after it is released. Therefore, there is a need in the art to provide a means for protecting copyrights in content once streamed over a network. The present invention was designed to address both needs.
Currently, no streaming media solution actually encrypts the data that is being sent from the server to the client. One solution can accomplish this with existing technology, such as by merging SSL secure HTTP sockets with a streaming software package, such as Quicktime. Unfortunately, Quicktime does not have a full screen view option. Therefore, there is a need in the art to develop a better method for streaming video data.
SUMMARY OF THE INVENTION
The present invention provides a process for encrypting a data stream to secure the data stream to enable only single viewing, comprising:
(a) providing a client selection for a streaming data transmission
(b) opening a connection to a streaming server and sending URI, token and user information to the streaming server, wherein the streaming server comprises a client data connection module to send data packets to a client, an encryption module to use encryption keys negotiated with the client to encrypt the data stream and operably connected to the client data connection module, and a flow control module for controlling the rate of data stream flow to maintain a full client buffer, while modifying a quality of the data within the data stream based on a determined bandwidth between the streaming server and the client;
(c) approving or disapproving a valid or invalid, respectively, URI and token combination on a transaction server, wherein the transaction server comprises a client interaction module for connecting a user to the transaction server component, a user verification module having a user database wherein the user verification module is operably linked to the client interaction module and checking for a valid user, and a URI and token creation module operably linked to the user verification module for creating new URIs and tokens in response to user requests; and
(d) providing a continuously encrypted data stream to the client if a valid URI and token combination was found.
Preferably, the streaming server component further comprises a read buffer module operable connected with the flow control module for reading in data from a source footage on storage medium. Preferably, the streaming server component further comprises a user interface module operably connected to the file system module or flow control module for setting server options. Preferably, the streaming server further comprises client server component comprising a data stream control protocol module to create an initial connection to the streaming server component, a decryption module to decrypt the incoming data stream, an input buffer module to buffer incoming data streams, and a display control module to control the display of streaming data. Most preferably, the client server component further comprises a display module to display audio and video data.
Preferably, the providing the continuously encrypted data stream step (d) further comprises a user interface module in the streaming server to allow for pausing, stopping, playing or restarting the data stream. Preferably, the transaction server is implemented with ASP scripts for encryption.
The present invention further comprises a streaming server for encrypting a data stream to secure the data stream to enable only single viewing, comprising:
(a) a streaming server component, wherein the streaming server component comprises a client data connection module to send data packets to a client; and encryption module to use encryption keys negotiated with the client to encrypt the data stream and operably connected to the client data connection module, and a flow control module for controlling the rate of data stream flow to maintain a full client buffer and further modifying a compression quality of the data within the data stream based on a determined bandwidth; and
(b) a transaction server component, wherein the transaction server component comprises a client interaction module for connecting a user to the transaction server component, a user verification module having a user database wherein the user verification module is operably linked to the client interaction module and checking for a valid user, and a URI and token creation module operably linked to the user verification module for creating new URIs and tokens in response to user requests.
Preferably, the streaming server component further comprises a read buffer module operable connected with the flow control module for reading in data from a source footage on storage medium. Preferably, the streaming server component further comprises a user interface module operably connected to the file system module or flow control module for setting server options. Preferably, the streaming server further comprises a client server component comprising a data stream control protocol module to create an initial connection to the streaming server component, a decryption module to decrypt the incoming data stream, an input buffer module to buffer incoming data streams, and a display control module to control the display of streaming data. Most preferably, the client server component further comprises a display module to display audio and video data.
Moreover, the streaming of the data may be performed using a variety of mechanisms. Thus, in one embodiment, the streaming may employ a progressive download streaming, or fast start approach, that enables a received portion of the data to be played while other portions of the data are still being streamed. However, other mechanisms may also be employed, including, but not limited to real-time streaming, broadcasting, PHP Hypertext pre-preprocessing streaming, or the like.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a schematic of the client component enabled to receive and view an encrypted data stream. The client component contains a token storage module 100 , a stream control protocol module 120 , and a decryption module 160 .
FIG. 2 shows a schematic of the streaming server component having an encryption module 220 and a client control connection module for key negotiation and token verification 200 .
FIG. 3 shows a schematic of the transaction server components having a token creation module 330 and a user verification module 310 .
FIG. 4 shows a schematic of various client scenarios showing the need for a token in order to unlock (decrypt) a data stream for viewing.
FIG. 5 shows a schematic of the process for the streaming server showing the receipt of a client token triggering a negotiation of encryption keys to allow viewing and receipt of a data stream.
FIG. 6 shows a schematic of the transaction server process providing for setting up of client accounts and token creation.
DETAILED DESCRIPTION OF THE INVENTION
The present invention provides a process to encrypt a data stream, such as multimedia entertainment and communications, via the Internet. The encrypted data stream will allow for copyrighted materials and multimedia communications (e.g., analyst meetings) on a secure, pay-per-view basis. The data stream cannot be stored on a client machine for future play-back, or retransmitted. A client, however, can view a data stream as many times as desired within a specified time frame.
A preferred encryption protocol provides, for example, an encryption algorithm of a 192-bit key (e.g., Triple DES), a UDP packet protocol, a RTSP (rfc 2326) packet transmission protocol, an RTP (rfc 1889) packet transmission control protocol, and MPEG1 video storage compression. However, the foregoing example of a preferred encryption protocol will change as such techniques improve with time.
One advantage of the inventive process, using the inventive streaming server and transaction server, is that the client does not really need to possess fully optimized equipment. Only one client will run on any one machine at any one time. The client will need to playback, for example, 30 fps 320×240 video and audio back with no jitter. This will require a stream of about 250˜300 kpa, a large data buffer (of at least several megabytes), and a 350 MHz Pentium II processor or greater running Windows 98 or Windows NT.
The server, for example, can be a fully optimized, multi-threaded (thread pool) Windows NT service. Unlike an HTTP server, this allows sessions with clients to be cached and the server will need to maintain state in respects to all clients.
DEFINITIONS
The following terms shall be used with the meanings defined herein.
Client shall mean the computer that the data is being sent to.
User shall mean the person executing instructions on the client.
Module shall mean a collection of compiled code designed to perform a specific function.
URI shall mean universal resource identifier, that is, the location on the server of the stream.
Token shall mean a binary piece of information that describes the permissions the user has for a specific stream.
In a preferred embodiment of the inventive process and streaming server, the video will be stored unencrypted on the server machines; the files will only be retrievable through the server software. The inventive server will be responsible for (1) negotiating a set of encryption keys; and (2) encrypting the video data “on the fly” thereby making the data packets that are actually going over the wire useless to any computer other than the intended machine. A preferred encryption standard is TRIPLE-DES with a 168-bit key. This form of encryption is not currently exportable outside of the US and Canada and is extremely secure. The server will use UDP for transmission of the data. This protocol uses considerably less network resources than other TCP protocols (http for example).
Client software will be responsible for decrypting the video data and playback. The encryption keys used will be different every time a movie is accessed. Every time the client is executed, a different encryption key is created so the client cannot play back earlier streams if they were somehow saved to disk.
Flow Charts
With regard to FIG. 1 , this shows a schematic of the client component of the inventive process and streaming server enabled to receive and view an encrypted data stream. The client keeps a list of all current streams and the corresponding tokens. This information is stored on the token storage module 100 . This list will consist of the following three items: (1) the URI, (2) the token for that URI, and (3) the expiration date given by the server. It is not desirable for the client to have any way of determining if the token is valid or not. Because of this, and the need to remove out of date tokens, the server returns the expiration date. This information is used by the client to display information. The expiration date itself never sent back to the server and the server verifies that the token passed is valid. Examples of module devices that can be used as token storage modules include, for example, Random Access Memory, secondary storage (hard disk), and embedded with software providing for token storage inventory and tracking of expiration dates.
The client communicates with a user interface 110 . The client will have a standard user interface that will give the appropriate user experience. The interface will have the ability to look through current valid streams or to connect to the server to search for other streams that could be viewed. The client user interface 110 communicates with a local display control module 130 and a stream control protocol module 120 . The client has to be able to setup a communications session with the server as well as control the flow of data from the server once the stream is being viewed. The stream control protocol module 120 creates the initial connection by connecting to the server, passing the requested URI, Token, and user information. The stream control protocol module 120 then negotiates a set of encryption keys and controls the flow of data from the server. Examples of stream control protocol module devices 120 within a client component that can be used to negotiate a set of encryption keys and control the flow of data from a server include, for example, Random Access Memory and the network interface card or modem. The software that will be uploaded into this module will monitor the rate of the data being received by sending network statistics to the streaming server. In one embodiment, the monitored rate of the data enables a bandwidth between the client and the streaming server to be determined. The display control module 130 controls the display of the data, and has the ability to pause, stop, or re-start the video stream. Examples of display control modules suitable for use within the client component include, Random Access Memory and the video card. The software running in this module will convert the data being sent form the server into a format that can be displayed to the user.
The display module 140 displays video and audio data. The input buffer module 150 is a module that contains the stream buffer. The stream buffer contains a circular buffer of decrypted data that the display control modules read from and the decryption module writes to. Examples of stream buffer module devices that can be used to contain a circular buffer of decrypted data include, for example, Random Access Memory. As packets are being received from the server, before the data is put into the input buffer, the data within the transport packet is decrypted by a decryption module 160 using the keys negotiated by the stream control protocol module 120 . A decryption module is available commercially, for example, SSL, DES, and RSA are available and suitable for use as a decryption module. Lastly on the client component sides is a data stream receive module 170 . This module handles the reception of the data packets sent by the server.
Appropriate module devices that can be used as a data stream receive module within the client component includes, for example, Random Access Memory. The software contained in this module will save the data being received by the client in a format that can be used by subsequent modules.
With regard to FIG. 2 , the client control connection module 200 will handle control communications between the client and the server. The client and server will negotiate a set of encryption keys. The client will send user information, the URI, and the token to the streaming server via the client control connection module 200 . From this module 200 , the data that is streamed to the client can be controlled (that is, paused, stopped, or restarted). Hardware devices suitable for use as a client control connection module within the streaming server include Random Access Memory. Such hardware components allow for the execution of hardware non-specific operations. Such software is either embedded in the client control connection module or uploaded therein. The software functions to create a process wherein the client and server communicate current network conditions and modify the data stream accordingly.
The client data connection module 210 functions to send data packets to the client using a connectionless protocol to reduce server overhead. Hardware devices suitable for use as a client data connection module within the streaming server include Random Access Memory and Network Interface Cards. Such software is either embedded in the client data connection module or uploaded therein. The software functions to create a process wherein the encrypted data is sent via network packets to the client machine.
The encryption module 220 uses the keys negotiated by the client/server to encrypt the data stream as it is being sent to the client. This allows for “on the fly” encryption and the encryption keys will be unique for all client/server connections. This allows the source footage to be stored unencrypted on the server. Hardware devices suitable for use as an encryption module within the streaming server include Random Access Memory and proprietary hardware encryption devices. Such hardware components include software that functions that do the actual encryption of the data. Such software is either embedded in the encryption module or uploaded therein. The software functions to create a process wherein the data being sent to the device is encrypted with the keys originally negotiated with the client and the output data is of a format that can only be read after being decrypted by the client.
The flow control module 230 makes sure that the data stream is being sent to the server at the rate in which the client is using the data. The buffer at the client needs to be full at all times but streaming data must also not be overwritten. Moreover, in one embodiment, encoding or compressing at least a portion of the data within the data stream may be based on a determined bandwidth. Thus, the flow control module communicates with both the encryption module 220 and uses feedback obtained from the client control connection module 200 . Hardware devices suitable for use as a flow control module within the streaming server include Random Access Memory. Such software is either embedded in the flow control module or uploaded therein. The software functions to create a process wherein the flow of data from the server to the client is regulated.
The file system read buffer 240 is for server performance. Small amounts of data read in from the file will be stored in memory instead of having a constant open file on the file system. The file system module 250 is responsible for reading in data from the source footage on the storage medium. The file system module communicates with the client control connection module 200 to open URIs and the user interface module 260 to file path configurations. Hardware devices suitable for use as a file system module within the streaming server include Random Access Memory. Such hardware components include software that functions to allow the access to data streams. Such software is either embedded in the file system module or uploaded therein. The software functions to create a process wherein the data stored on the secondary storage device can be loaded into Random Access Memory to be delivered to the encryption module.
The streaming server further provides a simple user interface module 260 for setting server options such as which network port to bind to and the location of source footage. Hardware devices suitable for use as a file system module within the streaming server include Random Access Memory. Such software is either embedded in the file system module or uploaded therein. The software functions to create a process wherein the user of the server software can tell the file system module where to go to find the data streams.
With regard to FIG. 3 , the transaction server comprises four module components. To access a video stream, the client must first obtain a transaction token. The transaction token is based on a pay-per-view scheme in which the token will be valid for a certain time period. The time a token is valid for is dependent on what the user selects and what options are available for the selected stream. The user contacts the transaction server, via a client interaction module 300 , with the user information and the URI. The transaction server will determine what time options are available for the token and present that to the user. After the user selects the required time limit, the request is passed off to the user verification module 310 . Hardware devices suitable for use as a client interaction module within the transaction server include Random Access Memory. Such software is either embedded in the client interaction module or uploaded therein. The software functions to create a process wherein the user information is verified against the database and a valid token is created based upon the options requested by the user.
The user verification module 310 checks for user information passed against a user database to see if the user is valid or not. The user database resides in memory of the user verification module. Hardware devices suitable for use as a user verification module within the transaction server include Random Access Memory. Such software is either embedded in the user verification module or uploaded therein. The software functions to create a process wherein the token passed are verified. The URI creation module 320 and the token creation module 330 are tied together and the token is based upon the request URI. This means that the token is unique to the request URI and cannot be used for any other stream. This information is then passed back to the client via module 300 . Hardware devices suitable for use as a URI creation module and token creation module, each located within the transaction server, include NA. Such hardware components include software that functions to Random Access Memory. Such software is either embedded in the URI creation module or token creation module or uploaded therein. The software functions to create a process wherein a valid URI to the media stream the user selected are created.
With regard to FIG. 4 , the client 400 executes and the client is loaded with a URI and a token 410 . The client either double clicks on the client's icon (no) or it launched by a media server (yes). If the media server launched the client, there will be a request URI and token in the command-line parameters of the client. A display a window ( 420 ) lists all the purchased (and current) data (video) streams available to view. The user will be able to select a data stream to view by double clicking on the title of the stream. The screen waits for input from the user ( 430 ) and the user selects a data stream or another housekeeping option ( 440 ). If a housekeeping option was selected, execute user request ( 450 ) and go back to displaying video streams with module 420 .
If the user launches a data stream (selects yes from 410 ) a URI and token is saved in the purchased video streams list so it can be viewed again at a later time 460 . A connection to the streaming server is opened and the URI, token and user information is sent to the streaming server 470 . The streaming server acknowledges a valid (or invalid) URI and token combination 480 . If the token is invalid or has expired, the server will close the connection and the client will go back and display all the data streams that are available to view. If the server acknowledges a valid URI and token combination, the client will start to receive data from the streaming server and display it 490 .
If the data stream finishes or the user selects any of the available stream options such as pause, stop, play, or restart 500 , the stream will stop and await further user input. If the stream has finished playing 510 , the process goes back to the list of available streams 420 , or continues displaying the data stream 490 by processing a user request 520 and then going back to displaying the stream 490 .
With regard to FIG. 5 and the process run by the streaming server, there is first a connection with the client control module 200 , 600 to allow the client to establish a connection with the streaming server. The client will provide the URI, token and user information 610 from user 470 . The streaming server determines if the token and URI are valid 620 . If the token is invalid or has expired, the connection to the client will be closed with an appropriate error message 630 . If token is valid, a set of unique encryption keys will be negotiated with the client 640 . A URI will be opened and streaming data will be read into a buffer 650 .
The client flow control module 230 provides for the client and streaming server to have a flow control connection established to make sure that the data stream is leaving the streaming server at the same rate it is being used at the client end 660 . This addresses bandwidth issues as well as making sure that the client play buffer is not overwritten. Therefore, the client flow control mechanism 660 uses the client flow control module 230 to obtain feedback from the data buffer in the client 710 and control the rate of the data stream to keep the client buffer as full as possible. If the client cannot accept any more data at this time, return to flow control module so indicates 670 to slow down or pause the streaming data. If the client can accept more data 680 , the client flow control will first determine if there are more data to stream 680 . If there are no more data to stream, the data stream could be completed, and the client connection will be closed 690 . If there is more data to be sent, the data waiting in the send buffer will be encrypted 700 and those data in the send buffer will be sent to the client 710 .
In one embodiment, a determined bandwidth may also be used to modify a quality of the data within the data stream. For instance, if a network bandwidth is determined to be above a first value, then at least a first portion of the data might be compressed or otherwise encoded at a first compression or encoding level. If the network bandwidth is determined at or below the first value, then the portion of the data might be compressed or otherwise encoded at a second compression or encoding level.
As an example, if the network bandwidth is above the first value, then the data might be encoded at a high definition (HD) level, otherwise, the data might be encoded or compressed at a lower level of quality, such as to a standard definition (SD) level. It should be understood, that multiple bandwidth thresholds may be employed to vary the encoding or compression of portions of the data and thereby modify the quality of the data based on an available bandwidth for streaming of the data. Thus, when the bandwidth varies, the quality of different portions of the data may dynamically vary for a given data stream. Therefore, the quality of different portions of a given data stream may vary over time based changes in a determined bandwidth.
The monitoring for the bandwidth may be performed at one or more of blocks 660 , 670 , 680 , and/or block 700 , without departing from the scope of the invention.
The variation of compression/encoding of the data may be implemented using any of a variety of mechanisms. For example, in one embodiment, the compression/encoding of portions of the data may be performed virtually in real-time, such that as a change in bandwidth is detected based on the above, the change in compressing of a next portion may be dynamically varied. However, the invention is not so limited, and other embodiments might include, for example, pre-encoding or pre-compressing the data, for example, in various defined bitrates. Then as the change in bandwidth indicates a change in the compression/encoding of the data, portions of the pre-compressed/encoded content may be retrieved at a place in the stream such that the stream appears seamless to the client, but, changing in compression/encoding.
It should be noted that the invention may employ any of a variety of mechanisms to stream the data to the client at 710 , including, but not limited to real-time streaming, PHP streamlining, progressive downloading, any of a variety of pseudo-streaming mechanisms, or the like.
With regard to FIG. 6 at the transaction server, the client first connects to the transaction server, for example through a web page 800 . Preferably, the transaction server will be implemented with ASP scripts. The client sends request URI and user information through ASP command-line arguments 810 and the transaction server user verification module 310 will determine the time limits of available tokens and display to user for selection. The transaction server will look up user information 820 in a database in the user verification module 310 . Examples of looking up user information are whether or not a user has an account (exists according to the transaction server) 830 . If the user does not have an account 840 , a transaction will be opened up to create new account page and get information from the user 840 . In addition, the transaction server user verification module 310 will determine if the URI that was requested is free of charge 850 . If the URI costs money 860 , the transaction server user verification module 310 will debit a credit card that is in the user database. This process will create a URI in the URI creation module 320 of the transaction server.
Once a URI is provided and either paid for or provided free, a token will be created 870 in the token creation module 330 . The token now created will be linked with the URI and a time limit will be selected 880 . Lastly, the viewer will be started on the client machine and sent back to the client along with the URI and the created token. | There is disclosed a process for encrypting a data stream to secure the data stream for single viewing and to protect copyrights of the data stream. Specifically, there is disclosed a process for protecting streaming multimedia, entertainment and communications in an Internet-type transmission. There is further disclosed a streaming server component operably connected with a streaming server that interacts with a client system to affect the inventive process. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to foreign French patent application No. FR 10 59151, filed on Nov. 5, 2010, the disclosure of which is incorporated by reference in its entirety.
FIELD OF THE DISCLOSED SUBJECT MATTER
[0002] The field of the invention is that of surface coatings, notably for surfaces exposed to any type of stress, for example a load (for a floor) or even substantial heating (for a kitchen worktop) or even chemical attack by acidic cleaning products.
[0003] BACKGROUND
[0004] Currently there are many classes of highly resistant surface coatings but the logistics of these coatings are generally quite complicated and when it is desired to change them, for reasons of wear-and-tear or a change in decor, the latter operation is also costly.
[0005] Thus, at the present time, when a user desires to change a decorative coating on a floor or kitchen or bathroom wall, for example a tiled floor or wall, usually they remove the tiling and undertake rather skilled work to fit a new set of tiles. The same is true when a user desires to change a kitchen worktop matched with the surrounding tiling.
[0006] While the public's obsession for redecorating is continuing to grow it is increasingly desired to find solutions that make this type of job easier for users, and more particularly for DIY users, while improving the appearance of these renovating coatings.
[0007] It has already been proposed to use purely synthetic coatings based on decorative paint, comprising organic protective resins; nevertheless, such decorative coatings have a number of drawbacks that the solution of the present invention proposes to alleviate. Specifically, a coat of paint covered with a simple synthetic resin layer, even if this layer is thick, is unsatisfactory when used to cover substantially inhomogeneous surfaces (for instance to cover a missing tile). Moreover, during surface renovation of flooring combined with under-floor heating, purely synthetic coatings do not necessarily provide optimal conduction of heat.
[0008] SUMMARY
[0009] This is why, in this context, the subject matter of the present invention relates to a method for producing a decorative coating on a surface made of a mineral compound that is possibly ceramic or earthenware, characterized in that it comprises at least the following steps:
depositing an adhesive primer layer on said surface made of a mineral compound; depositing a concrete layer; hardening said concrete layer; and depositing a decorative layer.
[0014] According to one embodiment, the concrete may be a concrete.
[0015] According to one embodiment of the invention, the method furthermore comprises a step of producing patterns in the concrete layer.
[0016] According to one embodiment of the invention, the method comprises applying a mould allowing said patterns to be produced, before the step of hardening said concrete layer.
[0017] According to one embodiment of the invention, the method furthermore comprises applying a demoulding agent to the concrete layer before hardening, said agent possibly being sand-based.
[0018] According to one embodiment of the invention, said patterns are produced by successive, local applications of a mould moved step-by-step over the entire area to be treated.
[0019] According to one embodiment of the invention, the method furthermore comprises deposition of an upper layer of protective resin.
[0020] According to one embodiment of the invention, the adhesive primer layer is deposited using a paint roller.
[0021] According to one embodiment of the invention, the concrete layer is deposited using a lacquer roller that allows the thickness of the concrete layer to be controlled.
[0022] According to one embodiment of the invention, the layer comprising slaked lime and component aggregates such as marble or granite is deposited using a roller.
[0023] According to one embodiment of the invention, the concrete comprises a mineral compound such as granite, and at least one dehydrated synthetic mineral resin.
[0024] According to one embodiment of the invention, the decorative layer comprises a layer comprising slaked lime and component mineral aggregates that are possibly made of marble or granite.
[0025] According to one embodiment of the invention, the layer comprising slaked lime and marble furthermore comprises powdered natural oxides or earths to give it color.
[0026] According to one embodiment of the invention, the decorative layer comprises a two-component paint comprising at least a first pre-polymer component based on bisphenol and epichlorohydrin and at least a second polyamine component.
[0027] According to one embodiment of the invention, the decorative layer is a layer of what is called patina paint comprising a resin and slaked lime allowing aged color effects to be obtained.
[0028] According to one embodiment of the invention, the method furthermore comprises deposition of an intermediate layer, called an impregnating layer, on the surface of the layer comprising slaked lime and marble so as to set the mineral material, said impregnating layer being resin- and silicate-based.
[0029] According to one embodiment of the invention, the protective resin is a microporous resin that is possibly made of polyurethane.
[0030] According to one embodiment of the invention, the protective resin is a two-component resin comprising at least a first pre-polymer component based on bisphenol and epichlorohydrin and at least a second polyamine component.
[0031] According to one embodiment of the invention, the adhesive primer layer is an acrylic resin.
DETAILED DESCRIPTION
[0032] The invention will be better understood by virtue of the following non-limiting description.
[0033] Generally, the coating of the present invention may be designed and intended to cover surfaces of any type that it is desired to decorate or for which it is desired to change the decoration, whether it is an internal or external tiled floor or not. The coating of the invention may also be used to coat kitchen wall or worktop surfaces or even tiled surfaces in bathrooms or toilets, or even to coat furniture or appliances such as white goods.
[0034] Whatever the surface concerned, it is appropriate in a first step to deposit a first adhesive primer layer intended to support the concrete layer. In the case of a surface that is highly degraded locally and contains deep cracks, it is possible in a prior step to open the cracks and fill them with a filler material.
[0035] This adhesive primer layer may typically be an acrylic resin that may be applied using a roller or a spray gun.
[0036] Next the concrete layer is deposited. Generally, the term “concrete” is understood to mean a mixture of cement, sand and water. The cement acts as a binder in the hydraulic concrete. Cement consists of a powdered mixture of lime and argillaceous limestone, which hardens with water to form concrete. Moreover, gravel or gravel-like elements are added to the cement to give it strength.
[0037] Advantageously, the concrete used in the present invention may comprise a mineral-compound mixture based on granite powder and at least one dehydrated synthetic mineral resin.
[0038] Advantageously, the resin may be a dehydrated silicate mineral resin.
[0039] The granite powder may make up a small percentage of the mixture, typically about ten percent.
[0040] The concrete is mixed with water before deposition. The water provides bulk, via the dehydrated mineral resin, to the whole of the composition. The deposition is advantageously carried out using a lacquer roller ensuring a uniform surface and a controlled thickness. A lacquer roller, such as the roller that was the subject of the patent FR 2 923 402 filed by the applicants, may in particular be very suitable because of its thread, which may possibly be a screw thread, the dimensions of which allow the thickness to be controlled.
[0041] When it is desired to provide a surface composed of tiles, paving stones, or which is otherwise patterned, with a rendering that is patterned as before, while avoiding the tedious removal of said multi-element surface, it is possible to produce patterns by applying a mould to the surface of said concrete when the concrete is still wet and therefore unhardened. It is notably possible to follow the procedure described below:
a screed of said concrete is poured onto the adhesive primer layer, and then while the concrete is still wet; advantageously the wet concrete is covered with a pulverulent demoulding agent that is notably possibly sand-based; impressions from at least two identical moulds are applied step-by-step in succession over the surface of said concrete by applying pressure to the external face of the mould; and the moulds are demoulded vertically by moving them step-by-step along the concrete surface, until it has been completely treated.
[0046] Thus a unitary surface is obtained having patterns produced on the upper surface of the concrete.
[0047] After a hardening time, the decorative layer of the coating is deposited.
[0048] In the following embodiment, this layer may advantageously be made from a mixture of slaked lime, marble and dehydrated mineral resin. To give it color, the above elements are dry mixed with oxides or earths. Typically this composition may comprise about 5% marble powder and about 20% dehydrated resin.
[0049] This coating corresponds to a completely mineral, powdered decorative top-coat mortar, the color being provided by the powdered natural earths or oxides. The mineral mortar is naturally very resistant and a chemical resin does not need to be used.
[0050] It has exceptional qualities in terms of rendering and allows the appearance of natural stone, notably identical in aspect to marble, to be recreated over the entire support and notably for floors, walls, worktops and basins, showers, patios, etc.
[0051] It may be applied with a small thickness, possibly with a thickness typically lying between 3 mm to 6 mm, using a lacquer roller. Its use enables renovation without difficult procedures. For decoration purely of a wall, it may be applied more thinly.
[0052] If required, it is possible for this layer to consist of two coats, the second coat being deposited after a drying time which may typically be about 24 hours.
[0053] According to another embodiment of the invention, and in order to recreate the appearance of aged colors, the decorative layer may be a coat of paint comprising slaked lime and resin.
[0054] The decorative layer may also be based on paint known from the prior art. It may be a two-component paint. This two-component paint may notably furthermore comprise mineral fillers such as titanium dioxide and/or mica and/or barium sulphate and/or talc and/or alkali metal silicates, which reinforce said paint, making it resistant to attack by acids present in conventional cleaning products.
[0055] Advantageously, the two-component paint is a water-based paint that can be used to produce decorative effects similar to those of water-based acrylic paints.
[0056] Before continuing with the deposition of the protective resin an intermediate layer called an impregnating layer, notably a layer based on resin and silicate, may be applied so as to set the mineral material of the lower layers.
[0057] Lastly and advantageously a protective resin is deposited, notably in the case of flooring and of surfaces exposed to moisture (for example in bathrooms, shower cubicles, bathtubs, etc.).
[0058] The resin may be a microporous resin based on polyurethane with a satin, gloss or matt appearance, the benefit of the microporosity being that it enables evaporation of incorporated water, so as to set the dehydrated resin-based compositions.
[0059] Nevertheless, it is also possible to use two-component resins, particularly impact-resistant resins.
[0060] This type of protective resin has particular strength properties. This type of resin is advantageously translucent or even transparent and allows the decoration produced beforehand to be seen. It may advantageously itself comprise inclusions that reinforce the decorative effect. These inclusions may be of any type: decorative micro-objects for bathroom- or toilet-based elements, inclusions that may be made to emit light for flooring via addition of luminescent or phosphorescent particles, etc. In this case, the protective resin is advantageously thicker, having a thickness of about 1000 microns. | A method for producing a decorative coating on a surface made of a mineral compound that is ceramic or earthenware, the method including: depositing an adhesive primer layer on said surface made of a mineral compound; depositing a concrete layer; hardening said concrete layer; and depositing a decorative layer. Advantageously, the concrete may be a self-levelling concrete. | 4 |
This is a continuation of co-pending application Ser. No. 08/087,626 filed on Jul. 1, 1993.
BACKGROUND OF THE INVENTION
The invention is a process for making 5-substituted-1H-tetrazoles from nitriles using a Lewis acid and an azide or a preformed metal azide complex. The process is exceptionally useful for synthesizing sterically hindered 5-substituted-1H-tetrazoles.
The classical method (W. G. Finnegan et al., J. Am. Chem. Soc. 1958, 80, 3908) of synthesizing tetrazoles from nitriles uses ammonium chloride/sodium azide/N,N-dimethylformamide, but this fails to react, in acceptable yield and purity, on sterically hindered nitriles. Hindered 5-substituted-1H-tetrazoles cannot be synthesized in acceptable yield or purity using ammonium chloride/sodium azide/N,N-dimethylformamide. Exothermic decomposition of the reaction products occurs yielding volatile products with a large heat of decomposition, thereby making the reaction unsafe.
The method of J. V. Duncia (J. Org. Chem., 1991, 56, 2395) uses trimethyltin or tributyltin azide to produce tetrazoles in good yield. Trimethyltin azide must be prepared in advance and tributyltin azide is prepared in situ. When working with large scale preparations, the tin by-products are difficult to remove, thus requiring extensive and tedious chromatography. The use of anhydrous hydrogen chloride gas, used to cleave the tin-tetrazole bond, is not desired when working with large quantities.
The sterically hindered 5-substituted tetrazoles of the present invention are useful as intermediates in a variety of compounds, particularly as intermedaites in preparing biphenyl-tetrazole angiotensin II receptor antagonists useful as cardiovascular agents. See, for example European Patent Application No. EP-253310, EP-324377, and EP-497150.
SUMMARY OF THE INVENTION
The invention is a process for synthesizing 5-substituted tetrazoles of formula I: ##STR2## wherein R is selected from: (a) straight or branched, substituted or unsubstituted (C 1 -C 6 )alkyl, wherein the substitution is hydrogen, (C 1 -C 6 )alkyl, (C 1 -C 6 )alkoxy, hydroxyl, nitro, trifluoromethyl, pyridine, thiophene, furan, phenyl, or substituted phenyl wherein the substitution is (C 1 -C 3 )alkyl, trifluoromethyl, nitro, --O(C 1 -C 3 )alkyl, or amino; and (b) moieties of the formula: ##STR3## R 1 and R 2 are independently selected from hydrogen, halogen, (C 1 -C 6 )alkyl, (C 1 -C 6 )alkoxy, hydroxyl, nitro, trifluoromethyl, pyridine, thiophene, furan, phenyl and substituted phenyl wherein the substitution is (C 1 -C 3 )alkyl, trifluoromethyl, nitro, --O(C 1 -C 3 )alkyl, or amino;
R 3 is a substituted or unsubstituted, straight or branched (C 1 -C 9 )alkyl wherein the substitution is hydrogen, (C 1 -C 4 )alkyl, phenyl, substituted phenyl wherein the substitution is (C 1 -C 3 )alkyl, trifluoromethyl, nitro, --O(C 1 -C 3 )alkyl, or amino; pyridine, thiophene, furan, --O(C 1 -C 4 )alkyl, hydroxyl or (C 1 -C 4 )alkyl--C(═O)--O--;
R 4 is (C 1 -C 6 )alkyl;
and the pharmaceutically acceptable salts thereof; which comprises:
reacting a compound of formula: R--CN wherein R is as defined hereinabove; with a Lewis acid and an azide or a preformed metal azide complex, in a polar solvent at reflux temperature for from 4 to 72 hours; acidifying and recovering the 5-substituted tetrazole I so produced in excellent yield and purity.
The preferred compounds of formula I are those wherein:
R is selected from (a) straight or branched, substituted or unsubstituted (C 1 -C 6 )alkyl, wherein the substitution is hydrogen, (C 1 -C 6 )alkyl, (C 1 -C 6 )alkoxy, hydroxyl, nitro, trifluoromethyl, pyridine, thiophene, furan, phenyl, or substituted phenyl wherein the substitution is (C 1 -C 3 )alkyl, trifluoromethyl, nitro, --O(C 1 -C 3 )alkyl, or amino; and (b) moieties of the formulae: ##STR4## R 1 and R 2 are independently selected from hydrogen, halogen, (C 1 -C 6 )alkyl, (C 1 -C 6 )alkoxy, hydroxyl, nitro, trifluoromethyl, pyridine, thiophene, furan, phenyl and substituted phenyl wherein the substitution is (C 1 -C 3 )alkyl, trifluoromethyl, nitro, --O(C 1 -C 3 )alkyl, or amino;
R 3 is selected from moieties of the formulae: ##STR5## wherein R 5 is hydrogen or (C 1 -C 4 )alkyl;
R 6 is hydrogen, (C 1 -C 4 )alkyl, pyridine, thiophene, furan, phenyl, or substituted phenyl wherein the substitution is (C 1 -C 3 )alkyl, trifluoromethyl, nitro, --O(C 1 -C 3 )alkyl, or amino;
R 7 is (C 1 -C 4 )alkyl, pyridine, thiophene, furan, phenyl, or substituted phenyl wherein the substitution is (C 1 -C 3 )alkyl, trifluoromethyl, nitro, --O(C 1 -C 3 )alkyl, or amino;
R 8 is (C 1 -C 4 )alkyl;
R 9 is hydrogen, (C 1 -C 4 )alkyl, pyridine, thiophene, furan, phenyl, or substituted phenyl wherein the substitution is (C 1 -C 3 )alkyl, trifluoromethyl, nitro, --O(C 1 -C 3 )alkyl, or amino;
R 4 is (C 1 -C 6 )alkyl;
n is an integer from 0-3;
and the pharmaceutically acceptable salts thereof.
The most preferred compounds of formula I are those wherein:
R is selected from (a) substituted (C 1 -C 6 )alkyl wherein the substitution is hydrogen, (C 1 -C 6 )alkyl, (C 1 -C 6 )alkoxy, hydroxyl, nitro, trifluoromethyl, pyridine, thiophene, furan, phenyl, or substituted phenyl wherein the substitution is (C 1 -C 3 )alkyl, trifluoromethyl, nitro, --O(C 1 -C 3 )alkyl, or amino; and (b) moieties of the formulae: ##STR6## R 1 and R 2 are independently selected from hydrogen, halogen, (C 1 -C 6 )alkyl, (C 1 -C 6 )alkoxy, hydroxyl, nitro, trifluoromethyl, pyridine, thiophene, furan, phenyl, or substituted phenyl wherein the substitution is (C 1 -C 3 )alkyl, trifluoromethyl, nitro, --O(C 1 -C 3 )alkyl, or amino;
R 3 is selected from moieties of the formulae: ##STR7## R 4 is (C 3 -C 4 )alkyl; and the pharmaceutically acceptable salts thereof.
The most particularly preferred compounds of formula I are those wherein:
R is selected from substituted (C 1 -C 6 )alkyl wherein the substitution is hydrogen, (C 1 -C 6 )alkyl, (C 1 -C 6 )alkoxy, hydroxyl, nitro, trifluoromethyl, pyridine, thiophene, furan, phenyl, or substituted phenyl wherein the substitution is (C 1 -C 3 )alkyl, trifluoromethyl, nitro, --O(C 1 -C 3 )alkyl, or amino; and moieties of the formula: ##STR8## R 3 is selected from moieties of the formulae: ##STR9## R 4 is (C 4 )alkyl; and the pharmaceutically acceptable salts thereof.
The Lewis acid is any acceptable Lewis acid as known in the art such as zinc chloride, magnesium chloride, aluminum chloride, aluminum isopropoxide or tin tetrachloride. The azide is sodium azide or trimethylsilyl azide and equivalents thereof. A preformed metal azide complex, zinc azide bispyridine complex, may be used instead of the separate Lewis acid and azide.
In the present invention the temperature of the reaction is able to go higher without decomposing the reagent. The higher reaction temperature makes it possible to react very hindered nitriles, such as 2,2-dimethylbenzylnitrile and 2,2-diphenylpropionitrile, with a Lewis acid and an azide or the preformed metal azide complex, to obtain the corresponding 5-substituted-1H-tetrazole.
The above conditions have not been used previously in the synthesis of 5-substituted-1H-tetrazoles.
The advantages of using the procedure of this invention are:
1. the reagent does not have to be prepared in advance;
2. the yields are higher overall;
3. the work-up procedure is simple;
4. the products are purer and do not need to be chromatographed before they are used;
5. the reaction times are shorter;
6. the reagents are cheaper;
7. the reagents are less toxic and there is no odor problem; and
8. hindered 5-substituted-1H-tetrazoles can be synthesized in high yield.
DETAILED DESCRIPTION OF THE INVENTION
The process and compounds of the present invention are described in the following reaction: ##STR10##
In accordance with Scheme 1, 1 mole of R--CN, wherein R is as defined hereinabove, dissolved in a polar solvent is preferably reacted with 3 moles of a Lewis acid and 5.05 moles of an azide for from 4-72 hours at the reflux temperature of the reaction. The reaction is cooled to room temperature and acidified to pH 1 with 10% aqueous hydrochloric acid. The acidified solution is added to ice water, stirred and the resulting precipitate is collected. The solid is washed with water and dried. The purity of the products is such that no further purification (chromatography or recrystallization) is required.
Preferably, the process is carried out such that the molar ratio of reactants is 1 mole of nitrile:3 moles of Lewis acid=5.05 moles of sodium azide (1:3:5.05).
As stated, the process of the present invention provides a method of preparing the hindered tetrazoles in significantly higher yields than the procedures of the prior art. For example, J. V. Duncia (J. Org. Chem., 1991, 56, 2395) prepares the hindered 5- 1,1-diphenylethyl!-1H-tetrazole, in 9% yield. In contrast thereto, using the method of the present invention, we are able to prepare 5- 1,1-diphenylethyl!-1H-tetrazole in 87% yield.
The following specific examples are provided to further illustrate the process of the present invention and the manner in which it may be carried out. It will be understood, however, that the specific details given in the examples have been chosen for purposes of illustration and are not to be construed as a limitation on the invention.
EXAMPLE 1
5-(4'-Methyl 1,1'-biphenyl!-2-yl)-1H-tetrazole
To a 700 g solution of 4'-methyl 1,1'-biphenyl!-2-carbonitrile in 10 liters of N,N-dimethylformamide, is added 1438 g of zinc chloride and 1180 g of sodium azide. The reaction mixture is heated at reflux temperature for 36 hours, cooled to room temperature and acidified with 9.8 liters of 10% aqueous hydrochloric acid(pH 1). The resulting solution is added with stirring to 48 liters of ice-water and the mixture is stirred for one hour. The precipitate is collected, washed with water, and dried in a forced air oven at 50° C. to give 807 g (yield=94% of theory) of the desired product.
mp 144°-148° C.
Purity=92.7 area % by HPLC
EXAMPLE 2
5-(4'-Methyl 1,1'-biphenyl!-2-yl)-1H-tetrazole
The title compound is prepared by the procedure of Example 1 using 1.49 g of 4'-methyl 1,1'-biphenyl!-2-carbonitrile, 10 ml of N,N-dimethylformamide, 4.47 g of zinc azide bis-pyridine complex (P. Rollin et al., Synthesis, 1990, 130), heated at reflux temperature for 18.25 hours, to give 1.6 g (yield=89% of theory) of the desired product.
mp 148°-149.5° C.
Purity=99.3 area % by HPLC.
EXAMPLE 3
5-(4'-Methyl 1,1'-biphenyl!-2-yl)-1H-tetrazole
The title compound is prepared by the procedure of Example 1 using 2.0 g of 4'-methyl 1,1'-biphenyl!-2-carbonitrile, 30 ml of N,N-dimethylformamide, 2.96 g of magnesium chloride and 3.37 g of sodium azide, heated at reflux temperature for 54 hours, to give 2.1 g (yield=84% of theory) of the desired product.
mp 144°-148° C.
Purity=96.0 area % by HPLC.
Substantially following the methods described in detail hereinabove, the compounds of this invention listed below in Examples 4-6 and 9-11 are prepared.
EXAMPLE 4
5-Phenyltetrazole
______________________________________Starting Material benzonitrileReagent zinc chloride and sodium azideSolvent N,N-dimethylformamideReaction Time 4 hours% Yield 83mp 216.6-217.9° C.______________________________________
EXAMPLE 5
5-(2-Bromophenyl)-1H-tetrazole
______________________________________Starting Material 2-bromobenzonitrileReagent zinc chloride and sodium azideSolvent N,N-dimethylformamideReaction Time 21 hours% Yield 51mp 181-184° C.IR(cm.sup.-1) 1605, 1248, 1057, 1029, 749______________________________________
EXAMPLE 6
5-(2,5-dimethylphenyl)-1H-tetrazole
______________________________________Starting Material 2,5-dimethylbenzonitrileReagent zinc and sodium azideSolvent N,N-dimethylformamideReaction Time 4.5 hours% Yield 61 (due to impure starting material)mp 157-162° C.IR(cm.sup.-1) 1587, 1507, 1250, 1059, 1040, 815.sup.1 H NMR(d.sub.6 -DMSO)d 7.52(s,1H), 7.40-7.29(m,2H); 2.44(s,3H); 2.35(s,3H).______________________________________
EXAMPLE 7
5-(2-Methoxyphenyl)-1H-tetrazole
The title compound is prepared by the procedure of Example 1 using 2-methoxybenzonitrile, zinc chloride, sodium azide and N,N-dimethylformamide. The reaction is heated at reflux temperature for 5 hours, acidified with 10% hydrochloric acid, extracted with ethyl acetate, dried and concentrated in vacuo. The residue is chromatographed (silica gel: 50% ethyl acetate/methylene chloride) to give 2.57 g (yield=36% of theory).
______________________________________mp 134-140° C.IR(cm.sup.-1) 1610, 1484, 1253, 1070, 1016, 748______________________________________
EXAMPLE 8
2-Butyl-6-(1-methoxy-1-methylethyl)-3- 2'-(1H-tetrazol-5-yl) 1,1'-biphenyl!-4-yl!methyl-4(3H)-quinazolinone
To a solution of 2.04 g of 4'- 2-butyl-6-(1-methoxy-1-methylethyl)-4-oxo-3(4H)-quinazolinyl!methyl!- 1,1'-biphenyl!-2-carbonitrile, prepared by the procedure described in B-765, in 40 ml of N,N-dimethylformamide is added 1.2 g of zinc chloride and 1.14 g of sodium azide. The reaction is heated at reflux temperature for 24.5 hours. An additional 1.2 g of zinc chloride and 1.14 g of sodium azide is added and the reaction is heated at reflux temperature for an additional 24.5 hours. The reaction is again recharged with 0.6 g of zinc chloride and 0.57 g of sodium azide and the heating continued for 18.5 hours. The mixture is cooled to room temperature and acidified to pH 1 with 50 ml of 10% hydrochloric acid. The mixture is added with stirring to 150 ml of ice-water and stirred for 1 hour. The resulting precipitate is collected, washed with water and dried in vacuo at 50° C. to give 1.6 g of the desired product.
Purity=87.6 area % by HPLC is desired product; 4.7 area % is starting material.
1 H NMR(CDCl 3 ): d 8.24(s, 1H); 8.0-7.75(m, 3H); 7.55-7.26 (m, 3H); 7.13-7.12(m, 4H); 5.43(br s, 2H); 3.11-3.08 (m, 2H); 3.07(s, 3H); 1.85-1.70(m, 2H); 1.55(s, 6H); 1.55-1.38(m, 2H); 0.88(t, 3H, J=7.3 Hz).
EXAMPLE 9
2-(1H-Tetrazol-5-yl)phenol
______________________________________Starting Material 2-cyanophenolReagent zinc chloride and sodium azideSolvent N,N-dimethylformamideReaction Time 4 hours% Yield 76mp 225-227° C.IR(cm.sup.-1) 3200, 1618, 1509, 1363, 1245, 1216, 1067, 1016, 748______________________________________
EXAMPLE 10
5-(1-Methyl-1-phenylethyl)-1H-tetrazole
______________________________________Starting material 2,2-dimethylbenzylnitrileReagent zinc chloride and sodium azideSolvent N,N-dimethylformamideReaction Time 18 hours% Yield 75mp 148-150° C.IR(cm.sup.-1) 1494, 1262, 1041, 751, 703.sup.1 H NMR(CDCl.sub.3)d 7.34-7.16(m,5H); 1,84(s,6H)______________________________________
EXAMPLE 11
5- 1,1-Diphenylethyl!-1H-tetrazole
______________________________________Starting Material 2,2-diphenylpropionitrileReagent zinc chloride and sodium azideSolvent N,N-dimethylformamideReaction Time 51.5 hours% Yield 87mp 130-134° C.IR(cm.sup.-1) 1595, 1494, 1268, 1067, 1029, 756, 700.sup.1 H NMR(CDCl.sub.3)d 7.40-7.20(m,6H); 7.20-7.00(m,4H): 2.19(s,3H);______________________________________ | A method for making 5-substituted tetrazoles of formula I: ##STR1## where R is as herein described which comprises reacting a compound of the formula R--CN with a Lewis acid and an azide or a preformed metal azide complex, acidifying and recovering the 5-substituted tetrazole. | 2 |
PRIORITY
[0001] The present invention claims priority under 35 USC section 119 based upon a provisional application which was filed on Dec. 4, 2009 and which has a Ser. No. of 61/266,542.
FIELD OF THE INVENTION
[0002] The present invention relates generally to air registers for regulation the flow of air from a heating or air-conditioning system.
BACKGROUND OF THE INVENTION
[0003] For a space that is ventilated by a forced central air system, air registers are used to cover air duct opening on walls, ceilings, and/or floors of the space. They allow air to flow into the space while preventing large objects from entering the duct.
[0004] Air registers typically consists of two parts: the grill, which is the outside part of the register used mainly to cover the opening, and the damper box, which is the inside part of the register used to control the air flow through the duct. The damper box is sized to fit within an air duct opening. The grill cover is typically designed with parallel louvers, but may have decorative patterns. Mass-produced, pre-manufactured air registers are prefabricated, or assembled by gluing or snapping the damper box and the grill cover together.
[0005] Air registers may be held in place within an air duct opening using friction between the damper box and the sides of the air duct opening and fasteners that pass through either the grill or the damper box into the surrounding surface.
[0006] Users may control the amount of air flow by pressing a lever or actuating another control on the damper box, which opens or closes the shutters to increase or reduce the amount of air streaming into the space. The direction of the air flow through the register is generally perpendicular to the air register grill as the air is pushed through the ducts. When the air register is located underneath or behind furniture in a room, the undirected flow of air may be restricted.
[0007] To address this problem, an air deflector may be used to redirect the air flow. An air deflector is a separate apparatus that is adhered or fastened to the grill. A typical air deflector is a curved piece of plastic that is attached to the grill using magnets or adhesive strips.
[0008] There are circumstances where it would be useful for the air deflector to be adjustable. The prior art air deflectors are either rigidly affixed to the air register, or are removable, but cannot be adjusted easily. A fixed air register is by definition not easily adjustable, and a removable air register must be stored and replaced each time the air flow is adjusted. There is a need for an air register having a deflector that is easily adjustable.
SUMMARY OF THE INVENTION
[0009] The invention may include a register for controlling the flow of a fluid from a duct, specifically for a heating and air conditioning system which may include a grill, a damper box sized to fit within the duct, the damper box may define a passage may have a first opening and a second opening, the first opening may be fluid communication with the grill, and the second opening may be fluid communication with the duct; and a deflector which may be mounted on a pivot axis that is rotatable from an extended position to a retracted position.
[0010] The deflector in the extended position may deflect fluid passing from the duct through the grill.
[0011] The invention may be further directed to a register as described above, where in the retracted position, the deflector at least partially may occlude the second opening.
[0000] The deflector may include a curved top wall.
The deflector may include a sidewall to connect to the curved top wall.
The deflector may include a protruding lip.
The damper box may include a bottom curved wall.
The damper box may include a sidewall to connect to the bottom curved wall.
The sidewall may include a raised surface.
The raised surface may include a slot to cooperate with a pivot axis.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The present invention will now be described by way of example with reference to the following drawings in which:
[0013] FIG. 1A is perspective view of a first embodiment of the invention;
[0014] FIG. 1B is side view the first embodiment in an extended position;
[0015] FIG. 1C is side view the first embodiment in a retracted position;
[0016] FIG. 2A is perspective view of a second embodiment of the invention in an extended position;
[0017] FIG. 2B is perspective view the second embodiment in a retracted position;
[0018] FIG. 2C is side view the second embodiment in a retracted position;
[0019] FIG. 2D is side view the second embodiment in an extended position;
[0020] FIG. 2E is perspective view the second embodiment with the deflector detached;
[0021] FIG. 3 is an exploded perspective view of a third embodiment of the invention showing its components; and
[0022] FIGS. 4A to C are perspective views of a fourth embodiment of the invention depicting the transition from an extended position to a retracted position.
DETAILED DESCRIPTION OF THE INVENTION
[0023] FIGS. 1A and 1C show a first embodiment of the invention which may include a grill 10 affixed to a damper box 12 to form an air register for an air vent.
[0024] The damper box 12 may define a passage through which air may flow. One end of the passage may open to the grill 10 , and the second end of the passage 14 may be in fluid communication with an air duct. The damper box may preferably be a rectangular prism may have a tapered portion at the second end 14 , but may be any shape that performs its function.
[0025] The grill 10 may define a plurality of openings which allow the passage of air. The grill 10 may also have a flange which extends outwardly around the edge of the grill 10 to rest upon any adjacent surface, but this flange may not be necessary for certain applications. In this preferred embodiment, the flange may include holes to permit a fastener, such as a screw, to be used to affix the air register to the air duct or adjacent surface.
[0026] The grill 10 is shown with a louvered grill pattern in all the figures, but may be decorated with any design pattern.
[0027] The air register further may include an air deflector 11 that may deflect air that is passing out of the grill 10 from the air duct. In this embodiment, the air deflector 11 may have two sides, and a curbed surface that act to redirect air from the air duct. It is preferred that each side may define at least a quarter circle, which in conjunction with the curved surface define a portion of a cylinder cut lengthwise. However, the air deflector may also have a plurality of flat surfaces joined along their long edges to create an approximately curved surface.
[0028] The air deflector 11 may pivot about a pivot axis 13 which is parallel to the plane in which the grill 10 generally lays, and which may pass through the grill 10 along that plane, or through a portion of the damper box 12 . The air deflector 11 may be permitted to pivot about the pivot axis using any known method, but preferably is mounted on the damper box 12 using rivets, screws or bolts. The air deflector 11 may be pivoted by a user using knobs or wheels affixed to the sides of the air deflector 11 in line with the pivot axis 13 . If the grill 10 has a flange, the grill 10 may have a slit 19 which permits the air deflector 11 to pass through the grill 10 as it pivots. The slit 19 may have a rubber or flexible gasket or seal to prevent debris from falling into the slit 19 .
[0029] The air deflector 11 may be moved between an extended position shown in FIG. 1B , and a retracted position in FIG. 1C . In the extended position, the air deflector 11 may deflect air that passes out the air register through the grill. In the retracted position, the air deflector 11 does not deflect any air that passes out of the air register through the grill 10 . In the retracted position, in a preferred embodiment, the air deflector 11 may partially or completed occlude the passage through the damper box at or near the second end 14 . This has the secondary effect of blocking the air vent, or otherwise controlling the flow of the air through the air register when the air deflector 11 is not in use redirecting air. Alternatively, the air register may have a separate device for controlling air flow through it, such as at least one movable louver, which may be used in conjunction with the moveable air deflector to control air.
[0030] Depending on the size and shape of the air duct opening and the depth of the damper box 12 , the damper box 12 may require a tapered portion at the second end 14 to allow enough clearance to permit the air deflector to move into the retracted position. The damper box 12 may also have a protrusion or stop 15 that extend from the side of the damper box 12 to prevent the air deflector from pivoting beyond the retracted position which may be more than is desirable.
[0031] In an embodiment designed to fit to a cylindrical air duct, the grill is circular, and the air deflector and damper box are hemispherical in shape. In this embodiment, the air deflector may be mounted on a ring which may rotate relative to the surrounding surface to allow the redirection of the air in many directions.
[0032] When in any position, the air deflector 11 may be kept in position by friction within the pivoting mechanism. Gaskets at the pivoting points may be used if the inherent friction at the pivoting points is not sufficient to keep the air deflector 11 in place.
[0033] In a preferred embodiment shown in FIGS. 2A to 2E , the air register may include a grill 20 mounted to a damper box 22 . The damper box 22 may have a passage extending therethrough to allow the passage of air from the air duct. The passage may have a first opening where the grill 20 is mounted to the damper box 22 , and a second opening 27 in fluid communication with an air duct. In their embodiment, the damper box may define a portion of a cylinder cut lengthwise twice, each cut may define an opening to create the passage.
[0034] The air register further may include an air deflector 21 that may be pivotable about a pivot axis 23 using a pivoting device at the pivot points where the pivot axis intersects the air register. In this embodiment, the pivoting device may include an axle 27 between the pivot points, where each end of the axle may be engaged to the sides of the air deflector 21 , and a wheel 26 mounted on the axle 27 . The wheel 26 may be rotated by hand to rotate the axle 27 and the air deflector 21 between a retracted position shown in FIG. 2C and an extended position shown in FIG. 2D . The grill 20 in this embodiment may have a flange, which as a slit 29 through which the deflector may pass when pivoted.
[0035] In this embodiment, as shown in FIG. 2E , the air deflector 21 may be removable, and may be engaged to the pivoting device manually. When in the extended position, if force is applied to the air deflector 21 in a direction that is roughly parallel to the surface surrounding the air register, the air deflector 21 may disengage from the rest of the device. This feature is a safety precaution to reduce the risk of injury to persons should something become caught on the air deflector 21 when in the extended position.
[0036] A similar embodiment is depicted in FIG. 3 , in an exploded assembly drawing. In this embodiment, the second opening 34 in the damper box 32 may be positioned off to one side of the damper box, and may not parallel to the grill 30 .
[0037] This air register may be manufactured and sold as a kit, and can be assembled by a purchaser using hand tools. Several clips may be used to attach the damper box 32 to the grill 30 . The air deflector 38 may have a small semicircular recess and a larger concentric semicircular indent at each end of its quarter-circle sides. When assembled, the recesses and indents may engage the knobs 36 . The knob 36 may be kept in place in the damper box using a screw 37 . The air deflector may pivot using the knobs 36 and rotate about the pivot axis.
[0038] The air deflector 31 may have a protruding lip 38 along its upper edge which may connect to the curved top wall 301 of the air deflector 31 . The curved top wall 301 which may be a quarter cylinder shaped wall and may be connected to the side wall 303 which may be a quarter round shaped wall. The sidewall 303 may include an exterior raised surface 305 which may define a slot 307 to cooperate with the pivot axis. When the air deflector is rotated into a retracted position, the protruding lip 38 prevents the air deflector 31 from falling completely below the grill 30 .
[0000] The damper box 32 may include a curved bottom wall 309 which may substantially a half cylinder shaped box and which may include a front protruding lip and may include a back protruding lip to cooperate with the grill 30 and may include a sidewall 311 which may connect to the curved bottom wall 309 and which may be substantially a semi circle in shape. The sidewall 311 may include a raised surface 313 which may include a slot or aperture 315 to cooperate with the pivot axis. The sidewall 311 may include a protruding lip to cooperate with the protruding lip of the curved bottom wall 309 and to provide a support surface for the grill 30 .
[0039] The air deflector 31 may also have a lip that extends from its lower edge. In this embodiment, when the air deflector 31 is pivoted to a retracted position underneath the grill 30 , and the protruding lip 38 is resting flush against the grill 30 , the air deflector may occlude the second opening 34 , preventing or impeding the passage of air from the air duct. The lip may overlap with the damper box 32 to further occlude the passage.
[0040] The air deflector 31 may be rotated to various positions within its rotation range and can be held in those positions by the friction created by the fastening of the parts with the knobs 36 and screws 37 . It can therefore be appreciated that a user can rotate the air deflector 31 to various positions to regulate both the direction and the amount or air flowing through the air register.
[0041] In another embodiment depicted in FIGS. 4A to 4C , the air register including a grill 40 and a pivotable air deflector 41 further may include a pivotable slit cover 48 , which rests against and pivots with the air deflector when in the extended position shown in FIG. 4A , but separates from the air deflector 41 when it passes through the slit in the grill 40 . As the air deflector 41 pivots into the retracted position, as shown in FIG. 4B and 4C , the slit cover 48 , which has a portion that is wider than the width of the slit, separates from the air deflector 41 and rests upon the grill 40 , thereby covering the slit. When the air deflector 41 is pivoted from the retracted to the extended position, the slit cover 48 is carried along with it as it passes through the slit.
[0042] The air deflector, the grill, and the damper box are made of any material suitable for their functions and currently available in the industry. Aluminum, steel and plastics may be particularly useful, separately and in combination, depending on the application.
[0043] This air register may be adapted for use in any application where a fluid, including a gaseous fluid, is moved from a duct to another volume, and it is advantageous to have both a grill covering the duct opening, and an a deflector to redirect the fluid.
[0044] The foregoing description illustrates only certain preferred embodiments of the invention. The invention is not limited to the foregoing examples. That is, persons skilled in the art will appreciate and understand that modifications and variations are, or will be, possible to utilize and carry out the teachings of the invention described herein. Accordingly, all suitable modifications, variations and equivalents are intended to fall within the scope of the claims. | An air register for covering an air duct opening in a space ventilated by a forced central air system. The invention permits the user to change the direction of the air flow by rotating the air deflector. The invention also permits the user to regulate the amount of the air flowing into the space by adjusting the shutter of the damper box, by rotating the air deflector, or by doing both. The invention therefore gives the user many options in selecting the desirable air flow setting. | 5 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of U.S. application Ser. No. 10/470,359 filed Jul. 24, 2003 which is the United States National Stage Application of International Patent Application No. PCT/US02/02501, filed on Jan. 29, 2002, which claims the benefit of U.S. Provisional Application No. 60/264,855, filed Jan. 29, 2001, the contents of each of which are incorporated by reference in their entirety.
FIELD
The present disclosure relates generally to indole compounds exhibiting cannabimimetic activity. The present disclosure is more particularly concerned with new and improved aminoalkylindole compounds exhibiting high binding affinity for at least one cannabinoid receptor and/or high selectivity for one cannabinoid receptor, pharmaceutical preparations employing these compounds and methods of administering therapeutically effective amounts of these compounds to provide a physiological effect.
BACKGROUND
Classical cannabinoids such as the marijuana derived cannabinoid Δ 9 -tetrahydrocannabinol, (Δ 9 -THC) produce their pharmacological effects through interaction with specific cannabinoid receptors in the body. So far, two cannabinoid receptors have been characterized: CB1, a central receptor found in the mammalian brain and peripheral tissues and CB2, a peripheral receptor found only in the peripheral tissues. Compounds that are agonists or antagonists for one or both of these receptors have been shown to provide a variety of pharmacological effects.
There is considerable interest in developing cannabimimetic compounds possessing high affinity for one of the CB1 or CB2 receptors. Such compounds may offer a rational therapeutic approach to a variety of disease conditions. One class of cannabimimetic compound encompasses indole derivatives such as the well-known aminoalkylindoles represented by WIN 55212-2 {(R)-(+)-[2,3-dihydro-5-methyl-3-[(4-morpholinyl)methyl]-pyrrolo[1,2,3-de]-1,4-benzoxazin-6-yl](1-naptha-lenyl)methanone}. Aminoalkylindoles of this type typically have a carbon linked alkylheterocyclic substituent at the indole-1 position, which is believed to be important for their cannabimimetic activities. These known materials are not selective for preferential activation of one of the CB1 or CB2 receptors.
SUMMARY
It has now been found that certain aminoalkylindoles possess surprising cannabimimetic properties, including selectivity for the CB1 or CB2 cannabinoid receptor. Broadly, in one aspect of the disclosure the novel cannabimimetic compounds can be represented by the structural formula I below, physiologically acceptable salts, diasteromers, enantiomers, double bond isomers or mixtures thereof.
wherein:
Z comprises at least one substituent independently chosen from hydrogen; halogen; CN; CF 3 ; hydroxy; alkoxy; thioalkoxy; aryl and lower alkyl;
Alk comprises an alkyl group or a substituted alkyl group;
X comprises NHSO 2 R 5 , a 5, 6 or 7 member heterocyclic ring, including at least one heteroatom independently selected from oxygen, nitrogen and sulfur; a substituted 5, 6 or 7 member heterocyclic ring, including at least one heteroatom independently selected from oxygen, nitrogen and sulfur; a bicyclic ring; or a bicyclic ring including at least one heteroatom independently selected from oxygen, nitrogen and sulfur;
R 5 comprises alkyl, halogenated alkyl and fluorinated alkyl;
R comprises hydrogen, CN, CHO, alkyl, halogenated alkyl, fluorinated alkyl or a substituted alkyl group;
Y comprises carbonyl, CH═CH (cis or trans), CONH or C═NH; and
A comprises alkyl, COCF 3 , adamantyl; azoadamantyl; cycloalkyl; phenyl; naphthyl; 9-anthracenyl; pyridinyl; quinolinyl; isoquinolinyl; quinazolinyl; an aliphatic bicyclic ring; an azabicyclic ring; a heterobicyclic ring; any of the above with one or more substituents independently selected from amino, halogen, hydroxy, nitro, nitroso, azido, isothiocyanato, cyano, COOH, alkyl, CONR 3 R 4 where R 3 and R 4 each independently comprise H, alkyl or substituted alkyl, NCOR 3 R 4 where R 3 and R 4 each independently comprise H, alkyl, substituted alkyl, CF 3 , SO 2 NR 3 R 4 where R 3 and R 4 each independently comprise H, alkyl, substituted alkyl or CF 3 ; or a salt of any of the above.
In one aspect of the disclosure the compounds can be represented by structural formula I above, wherein:
Z comprises hydrogen;
Alk comprises a C 1-2 alkyl group;
X comprises a 5, 6 or 7 member heterocyclic ring, including at least one heteroatom independently selected from oxygen, nitrogen and sulfur; a substituted 5, 6 or 7 member heterocyclic ring, including at least one heteroatom independently selected from oxygen, nitrogen and sulfur; a bicyclic ring; or a bicyclic ring including at least one heteroatom independently selected from oxygen, nitrogen and sulfur;
R comprises hydrogen;
Y comprises carbonyl; and
A comprises alkyl, COCF 3 , adamantyl; azoadamantyl; phenyl; naphthyl; 9-anthracenyl; pyridinyl; quinolinyl; isoquinolinyl; quinazolinyl; an aliphatic bicyclic ring; an azabicyclic ring; any of the above with one or more substituents independently selected from amino, halogen, hydroxy, nitro, nitroso, azido, isothiocyanato, cyano, COOH, alkyl, CONR 3 R 4 where R 3 and R 4 each independently comprise H, alkyl or substituted alkyl, NCOR 3 R 4 where R 3 and R 4 each independently comprise H, alkyl, substituted alkyl, CF 3 , SO 2 NR 3 R 4 where R 3 and R 4 each independently comprise H, alkyl, substituted alkyl or CF 3 ; or a salt of any of the above.
In one aspect of the disclosure the compounds can be represented by structural formula I above, wherein:
Z comprises hydrogen, I, F, CN or CF3 in any possible position or alkoxy in the 7 position;
Alk comprises a CH 2 ;
X comprises a piperidinyl ring with a CH 3 group attached to the first ring carbon atom or a morpholinyl ring with a CH 3 group attached to the first ring carbon atom or a morpholinyl ring;
R comprises hydrogen or CH 3 ;
Y comprises C═O or CONH; and
A comprises alkyl, COCF 3 , adamantyl; azoadamantyl; phenyl; naphthyl; 9-anthracenyl; pyridinyl; quinolinyl; isoquinolinyl; quinazolinyl; an aliphatic bicyclic ring; an azabicyclic ring; any of the above with one or more substituents independently selected from amino, halogen, hydroxy, nitro, nitroso, azido, isothiocyanato, cyano, COOH, alkyl, CONR 3 R 4 where R 3 and R 4 each independently comprise H, alkyl or substituted alkyl, NCOR 3 R 4 where R 3 and R 4 each independently comprise H, alkyl, substituted alkyl, CF 3 , SO 2 NR 3 R 4 where R 3 and R 4 each independently comprise H, alkyl, substituted alkyl or CF 3 ; or a salt of any of the above.
In another aspect of the disclosure the compounds can be represented by structural formula II below,
wherein:
Z comprises hydrogen;
R comprises hydrogen;
R 1 comprises N, O, S or CH 2 ;
R 2 comprises H, alkyl, CF 3 , CH 2 C≡CH, CH 2 CH═CH 2 or CH 2 Ph; and
A comprises alkyl, COCF 3 , adamantyl; azoadamantyl; phenyl; naphthyl; 9-anthracenyl; pyridinyl; quinolinyl; isoquinolinyl; quinazolinyl; an aliphatic bicyclic ring; an azabicyclic ring; any of the above with one or more substituents independently selected from amino, halogen, hydroxy, nitro, nitroso, azido, isothiocyanato, cyano, COOH, alkyl, CONR 3 R 4 where R 3 and R 4 each independently comprise H, alkyl or substituted alkyl, NCOR 3 R 4 where R 3 and R 4 each independently comprise H, alkyl, substituted alkyl, CF 3 , SO 2 NR 3 R 4 where R 3 and R 4 each independently comprise H, alkyl, substituted alkyl or CF 3 ; or a salt of any of the above.
Unless otherwise specifically defined, “acyl” refers to the general formula —C(O)alkyl.
Unless otherwise specifically defined, “acyloxy” refers to the general formula —O-acyl.
Unless otherwise specifically defined, “alcohol” refers to the general formula alkyl-OH and includes primary, secondary and tertiary variations.
Unless otherwise specifically defined, “alkyl” or “lower alkyl” refers to a linear, branched or cyclic alkyl group, having from 1 to about 16 carbon atoms and advantageously having from 1 to about 9 carbon atoms. The alkyl group can be saturated or unsaturated. The alkyl group can be unsubstituted, singly substituted or, if possible, multiply substituted, with substituent groups in any possible position. Alkyl groups include, for example, methyl, ethyl, propyl, butyl, hexyl, octyl, isopropyl, isobutyl, tert-butyl, cyclopropyl, tetramethylcyclopropyl, cyclohexyl, cyclooctyl, vinyl and allyl. Unless otherwise specifically limited, a cyclic alkyl group includes monocyclic, bicyclic, tricyclic and polycyclic rings, for example norbornyl, adamantyl and related terpenes.
Unless otherwise specifically defined, “alkoxy” refers to the general formula —O-alkyl.
Unless otherwise specifically defined, “alkylmercapto” refers to the general formula —S-alkyl.
Unless otherwise specifically defined, “alkylamino” refers to the general formula —(NH)-alkyl.
Unless otherwise specifically defined, “di-alkylamino” refers to the general formula —N(alkyl) 2 . Unless otherwise specifically limited di-alkylamino includes cyclic amine compounds such as piperidine and morpholine.
Unless otherwise specifically defined, an aromatic ring is an unsaturated ring structure, advantageously having about 4 to about 7 ring members, and including only carbon as ring atoms. The aromatic ring structure can be unsubstituted, singly substituted or, if possible, multiply substituted, with substituent groups in any possible position.
Unless otherwise specifically defined, “aryl” refers to an aromatic ring system that includes only carbon as ring atoms, for example phenyl, biphenyl or naphthyl. The aryl group can be unsubstituted, singly substituted or, if possible, multiply substituted, with substituent groups in any possible position.
Unless otherwise specifically defined, “aroyl” refers to the general formula —C(═O)-aryl.
Unless otherwise specifically defined, a bicyclic ring structure comprises 2 fused or bridged rings, advantageously having about 6 to about 12 ring atoms, that include only carbon as ring atoms. The bicyclic ring structure can be saturated or unsaturated. The bicyclic ring structure can be unsubstituted, singly substituted or, if possible, multiply substituted, with substituent groups in any possible position. The individual rings may or may not be of the same type. Examples of bicyclic ring structures include, Dimethyl-bicyclo[3,1,1]heptane, bicyclo[2,2,1]heptadiene, decahydro-naphthalene, bicyclohexane, bicyclooctane and bicyclodecane.
Unless otherwise specifically defined, a carbocyclic ring is a non-aromatic ring structure, saturated or unsaturated, advantageously having about 3 to about 8 ring members, that includes only carbon as ring atoms, for example, cyclohexadiene or cyclohexane. The carbocyclic ring can be unsubstituted, singly substituted or, if possible, multiply substituted, with substituent groups in any possible position.
Unless otherwise specifically defined, “halogen” refers to an atom selected from fluorine, chlorine, bromine and iodine.
Unless otherwise specifically defined, a heteroaromatic ring is an unsaturated ring structure, advantageously having about 4 to about 8 ring members, that has carbon atoms and one or more heteroatoms, including oxygen, nitrogen and/or sulfur, as ring atoms, for example, pyridine, furan, quinoline, and their derivatives. The heteroaromatic ring can be unsubstituted, singly substituted or, if possible, multiply substituted, with substituent groups in any possible position.
Unless otherwise specifically defined, a heterobicyclic ring structure comprises 2 fused or bridged rings, advantageously having about 6 to about 12 ring atoms, including carbon and one or more heteroatoms, including oxygen, nitrogen and/or sulfur, as ring atoms. The heterobicyclic ring structure is saturated or unsaturated. The heterobicyclic ring can be unsubstituted, singly substituted or, if possible, multiply substituted, with substituent groups in any possible position. The individual rings may or may not be of the same type. Examples of heterobicyclic ring structures include tropane, quinuclidine and tetrahydro-benzofuran.
Unless otherwise specifically defined, a heterocyclic ring is a saturated or unsaturated ring structure, advantageously having about 3 to about 8 ring members, that has carbon atoms and one or more heteroatoms, including oxygen, nitrogen and/or sulfur, as ring atoms, for example, piperidine, morpholine, piperazine, pyrrolidine, thiomorpholine, tetrahydropyridine, and their derivatives. The heterocyclic ring can be unsubstituted, singly substituted or, if possible, multiply substituted, with substituent groups in any possible position.
Unless otherwise specifically defined, a heterotricyclic ring structure comprises 3 rings that may be fused, bridged or both fused and bridged, and that include carbon and one or more heteroatoms, including oxygen, nitrogen and/or sulfur, as ring atoms. The heterotricyclic ring structure can be saturated or unsaturated. The heterotricyclic ring structure can be unsubstituted, singly substituted or, if possible, multiply substituted, with substituent groups in any possible position. The individual rings may or may not be of the same type. Examples of heterotricyclic ring structures include 2,4,10-trioxaadamantane, tetradecahydro-phenanthroline.
Unless otherwise specifically defined, a heteropolycyclic ring structure comprises more than 3 rings that may be fused, bridged or both fused and that include carbon and one or more heteroatoms, including oxygen, nitrogen and/or sulfur, as ring atoms. The heteropolycyclic ring structure can be saturated or unsaturated. The heteropolycyclic ring structure can be unsubstituted, singly substituted or, if possible, multiply substituted, with substituent groups in any possible position. The individual rings may or may not be of the same type. Examples of heteropolycyclic ring structures include azaadamantine, 5-norbornene-2,3-dicarboximide.
Unless otherwise specifically defined, the term “phenacyl” refers to the general formula -phenyl-acyl.
Unless otherwise specifically defined, a polycyclic ring structure comprises more than 3 rings that may be fused, bridged or both fused and bridged, and that includes carbon as ring atoms. The polycyclic ring structure can be saturated or unsaturated. The polycyclic ring structure can be unsubstituted, singly substituted or, if possible, multiply substituted, with substituent groups in any possible position. The individual rings may or may not be of the same type. Examples of polycyclic ring structures include adamantine, bicyclooctane, norbornane and bicyclononanes.
Unless otherwise specifically defined, a spirocycle refers to a ring system wherein a single atom is the only common member of two rings. A spirocycle can comprise a saturated carbocyclic ring comprising about 3 to about 8 ring members, a heterocyclic ring comprising about 3 to about 8 ring atoms wherein up to about 3 ring atoms may be N, S, or O or a combination thereof.
Unless otherwise specifically defined, a tricyclic ring structure comprises 3 rings that may be fused, bridged or both fused and bridged, and that includes carbon as ring atoms. The tricyclic ring structure can be saturated or unsaturated. The tricyclic ring structure can be unsubstituted, singly substituted or, if possible, multiply substituted, with substituent groups in any possible position, and may be substituted or unsubstituted. The individual rings may or may not be of the same type. Examples of tricyclic ring structures include fluorene and anthracene.
Unless otherwise specifically limited the term substituted means substituted by a below-described substituent group in any possible position. Substituent groups for the above moieties useful in this disclosure are those groups that do not significantly diminish the biological activity of the disclosed compound. Unless otherwise specifically limited a substituent group or a substituent group that does not significantly diminish the biological activity of the disclosed compound includes, for example, H, halogen, N 3 , NCS, CN, NO 2 , NX 1 X 2 , OX 3 , C(X 3 ) 3 , OAc, O-acyl, O-aroyl, NH-acyl, NH-aroyl, NHCOalkyl, CHO, C(halogen) 3 , COC(halogen) 3 , COOX 3 , SO 3 H, PO 3 H 2 , SO 2 NX 1 X 2 , CONX 1 X 2 , NCOX 1 X 2 , alkyl, substituted alkyl, phenyl, substituted phenyl, alcohol, alkoxy, alkylmercapto, alkylamino, di-alkylamino, sulfonamide or thioalkoxy (wherein X 1 and X 2 each independently comprise H, alkyl or substituted alkyl, or X 1 and X 2 together comprise part of a heterocyclic ring having about 4 to about 7 ring members and optionally one additional heteroatom selected from O, N or S, or X 1 and X 2 together comprise part of an imide ring having about 5 to about 6 members and X 3 comprises H, alkyl, loweralkylhydroxy, or alkyl-NX 1 X 2 ), NCOR 3 R 4 (where R 3 and R 4 each independently comprise H, alkyl, substituted alkyl, CF 3 ) or SO 2 NR 3 R 4 (where R 3 and R 4 each independently comprise H, alkyl, substituted alkyl or CF 3 , sulfonamide, or lower alcohol). Unless otherwise specifically limited, a substituent group may be in any possible position.
An isotope is one of two or more species of the same element. Each isotope of an element will have the same number of protons in its nucleus, the same atomic number and the same position in the Periodic Table. However each isotope of that element will have a different number of neutrons in its nucleus and therefore a different mass than other isotopes of that species. The term nuclide is sometimes used synonymously with the term isotope. As used herein a natural isotope has an atomic mass corresponding most closely with the atomic mass shown for that element in the Periodic Table. As used herein an unnatural isotope has an atomic mass that is further removed from the atomic mass shown for that element in the Periodic Table than the natural isotope. For example, protium (hydrogen-1 or 1 H) is the natural isotope of hydrogen and deuterium (hydrogen-2 or 2 H) and tritium (hydrogen-3 or 3 H) are all unnatural isotopes of hydrogen. The compounds of the present disclosure can comprise isotopes at one or more of their atoms. For example, the compounds can be radiolabeled with isotopes, such as tritium, carbon-11, carbon-13, carbon-14, oxygen-15, nitrogen-15, oxygen-18, fluorine-18, bromine-76, bromine-77, bromine-82, iodine-123 or iodine-125. The present disclosure encompasses all isotopic variations of the described compounds, whether natural or unnatural, radioactive or not.
In general, unless otherwise explicitly stated the disclosed materials may be alternately formulated to comprise, consist of, or consist essentially of, any appropriate components or moieties herein disclosed. The disclosed materials may additionally, or alternatively, be formulated so as to be devoid, or substantially free, of any components, materials, ingredients, adjuvants moieties or species used in the prior art compositions or that are otherwise not necessary to the achievement of the function and/or objective of the present disclosure.
When the word “about” is used herein it is meant that the amount or condition it modifies can vary some beyond the stated amount so long as the function and/or objective of the disclosure are realized. The skilled artisan understands that there is seldom time to fully explore the extent of any area and expects that the disclosed result might extend, at least somewhat, beyond one or more of the disclosed limits. Later, having the benefit of this disclosure and understanding the concept and embodiments disclosed herein, a person of ordinary skill can, without undue effort, explore beyond the disclosed limits and, when embodiments are found to be without any unexpected characteristics, those embodiments are within the meaning of the term about as used herein.
Some of the disclosed cannabinoid compounds exhibit high affinity for the CB1 and/or CB2 cannabinoid receptor. More specifically, some analogs showed similar or higher receptor binding affinity than the well-known indole cannabinoid WIN 55212-2. Thus, another aspect of the disclosure is use of at least one disclosed compound to interact with a cannabinoid receptor.
Some of the disclosed cannabinoid compounds show a surprisingly higher selectivity for one of the CB1 or CB2 cannabinoid receptors. These selective compounds are able to interact with one cannabinoid receptor, for example the CB2 receptor, without affecting the CB1 cannabinoid receptor to the same degree. More specifically, some of these compounds show not only comparable cannabimimetic activity with the compound WIN 55212-2, but also a surprisingly higher selectivity for one of the CB1 or CB2 receptors. Therefore, another aspect of the disclosure is use of at least one disclosed compound to preferentially interact with one cannabinoid receptor.
Some of the disclosed cannabinoid compounds can act as high affinity modulators for the CB2 cannabinoid receptor. The disclosed cannabinoid compounds therefore are potential therapeutic agents through the modulation of a cannabinoid receptor.
Some of the cannabinoid compounds described herein may be agonists for at least one of the cannabinoid receptors. The disclosed cannabinoid agonists interact with the at least one cannabinoid receptor binding site to initiate a physiological or a pharmacological response characteristic of that receptor. Therefore, a further aspect of the disclosure is use of at least one disclosed compound to initiate an agonistic response from a cannabinoid receptor.
Some of the compounds described herein may be cannabinoid receptor antagonists. The cannabinoid antagonists interact with the CB1 and/or CB2 cannabinoid receptor binding site to block other ligands from the receptor binding site without initiating a physiological or a pharmacological response characteristic of that receptor. Thus, cannabinoid antagonists typically oppose the cannabinoid receptor site response characteristics initiated by cannabinoid agonists. Therefore, an aspect of the disclosure is use of at least one disclosed compound to oppose initiation of an agonistic response from a cannabinoid receptor.
The disclosed cannabinoid compounds described herein, and physiologically acceptable salts thereof, have pharmacological properties when administered in therapeutically effective amounts for providing a physiological response in individuals and/or animals. Thus, another aspect of the disclosure is the administration of a therapeutically effective amount of at least one disclosed cannabimimetic compound, or a physiologically acceptable salt thereof, to an individual or animal to provide a physiological response.
Some of the halogen containing analogs, for example those analogs comprising iodide and fluoride, are potential radioactive probes for imaging in vivo the distribution of cannabinoid receptors.
Some of the radioactive isotope containing analogs have potential as radiopharmaceutical analogs (disclosed analogs that have been labeled with radioactive isotopes). These radiopharmaceuticals can be administered to patients and the emitted radiation can be measured. The majority of these diagnostic tests involve the formation of an image using a camera suitable to detect the emitted radiation. Positron emission tomography (PET) is one nuclear medicine tomographic imaging technique, which produces a three-dimensional image or map of functional processes in a patient's body. To conduct the PET scan, a short-lived radiopharmaceutical analog that decays by emitting a positron is administered into the subject (usually by injection into the blood stream). There is a waiting period while the radiopharmaceutical analog becomes concentrated in tissues of interest such as a cannabinoid receptor. After the waiting period the patient is placed in an imaging scanner. The scanner collects multiple images and a computer is used to apply an algorithm to the multiple images and provide a three dimensional image. Single photon emission computed tomography (SPECT) is another nuclear medicine tomographic imaging technique. To conduct the SPECT scan, a short-lived radiopharmaceutical analog that decays to produce a gamma ray is administered into the subject. There is a waiting period while the radiopharmaceutical analog becomes concentrated in tissues of interest such as a cannabinoid receptor. After the waiting period the patient is placed in an imaging scanner and SPECT imaging is performed by using a gamma camera to acquire multiple two dimensional images from multiple angles. A computer is then used to apply an algorithm to the multiple images to provide a three dimensional image.
A better understanding of the disclosure will be obtained from the following detailed description of the article and the desired features, properties, characteristics, and the relation of the elements as well as the process steps, one with respect to each of the others, as set forth and exemplified in the description and illustrative embodiments.
DETAILED DESCRIPTION
As used herein, a “therapeutically effective amount” of a compound, is the quantity of a compound which, when administered to an individual or animal, results in a sufficiently high level of that compound in the individual or animal to cause a discernible increase or decrease in stimulation of cannabinoid receptors. Such discernible increase or decrease in stimulation of cannabinoid receptors can provide a physiological effect in the individual or animal.
Physiological effects that result from CB1 cannabinoid receptor interaction with agonist compounds include relief of pain, peripheral pain, neuropathic pain, glaucoma, epilepsy and nausea such as associated with cancer chemotherapy; appetite enhancement; selective killing of glioma and breast cancer cells; alleviation of the symptoms of neurodegenerative diseases including Multiple Sclerosis, Parkinson's Disease, Huntington's Chorea and Alzheimer's Disease, reduction of fertility; prevention or reduction of diseases associated with motor function such as Tourette's syndrome; neuroprotection; suppression of memory and peripheral vasodilation. Physiological effects that result from CB1 cannabinoid receptor interaction with antagonist compounds include appetite suppression; memory enhancement; beneficial effects in mental disorders such as schizophrenia and depression; and beneficial effects in endotoxic and hypotensive shock. Physiological effects that result from CB2 cannabinoid receptor interaction with agonist compounds include relief of pain, peripheral pain, neuropathic pain, glaucoma, epilepsy and nausea such as associated with cancer chemotherapy; selective killing of glioma and breast cancer cells; alleviation of the symptoms of neurodegenerative diseases including Multiple Sclerosis, Parkinson's Disease, Huntington's Chorea and Alzheimer's Disease, reduction of fertility; prevention or reduction of diseases associated with motor function such as Tourette's syndrome; prevention or reduction of inflammation; neuroprotection; and suppression of the immune system. Physiological effects that result from CB2 cannabinoid receptor interaction with antagonist compounds include enhancement of the immune system and peripheral vasoconstriction. Typically a “therapeutically effective amount” of the novel compounds ranges from about 10 mg/day to about 1,000 mg/day.
As used herein, an “individual” refers to a human. An “animal” refers to, for example, veterinary animals, such as dogs, cats, horses and the like, and farm animals, such as cows, pigs and the like.
The compounds of the present disclosure can be administered by a variety of known methods, including orally, rectally, or by parenteral routes (e.g., intramuscular, intravenous, subcutaneous, nasal or topical). The form in which the compounds are administered will be determined by the route of administration. Such forms include, but are not limited to, capsular and tablet formulations (for oral and rectal administration), liquid formulations (for oral, intravenous, intramuscular or subcutaneous administration) and slow releasing microcarriers (for rectal, intramuscular or intravenous administration). The formulations can also comprise one or more of a physiologically acceptable excipient, vehicle and optional adjuvants, flavorings, colorants and preservatives. Suitable physiologically to acceptable vehicles may include, for example, saline, sterile water, Ringer's solution, and isotonic sodium chloride solutions. The specific dosage level of compound will depend upon a number of factors, including, for example, biological activity of the particular preparation, age, body weight, sex and general health of the individual being treated.
The following examples are given for purposes of illustration only in order that the present disclosure may be more fully understood. These examples are not intended to limit in any way the scope of the disclosure unless otherwise specifically indicated.
The prepared cannabimimetic indole derivatives can generally be described with reference to exemplary structural formulas 1 and 2 below.
The compounds of exemplary structural formula 1 include both racemics and two enantiomers. Some compounds are listed in TABLE 1.
Exemplary Structural Formula 1
It should be noted that alk-X for all of the materials of TABLE 1 was 1-(N-methyl-2-piperidinyl)methyl.
TABLE 1 K I nM analog Z R A CB1 CB2 2-7(R,S) H H 2-iodo-5-nitrophenyl 403 5.7 2-7(R) H H 2-iodo-5-nitrophenyl 285 0.53 2-7(S) H H 2-iodo-5-nitrophenyl 906 9.5 2-7(R,S) H H 2-iodo-5-nitrophenyl 1.6 human 2-24(R) H H 2-iodophenyl 1.8 2.1 2-24(S) H H 2-iodophenyl 561 583
Surprisingly, and as exemplified by compounds 2-7 and 2-24, in all cases the + configuration (R configuration) has a higher selectivity for the CB2 receptor and a higher affinity for the CB2 receptor.
Compound 2-7 was tested for binding affinity to human CB2 receptors using the below-described procedure with human tissue samples. That compound was found to be a surprisingly potent cannabinoid.
Exemplary Structural Formula 2
TABLE 2 Ki nM analog Z R R 1 R 2 A CB1 CB2 2-25 H H O CH 2 Ph 1217 1800 2-26 H H O CH 2 Ph 4212 1431 2-27 H H O CH 2 Ph 2383 927.5 2-28 H H O CH 3 27.93 226.3 2-29 H H O CH 3 848.1 48.45 2-30 H H O CH 3 464.3 153.5 2-31 H H O CH 3 5.696 26.56 2-32(R,S) H H CH 2 CH 3 239.4 (R,S) 3.411 (R,S) 2-32(R) H H CH 2 CH 3 139.7 (R) 1.416 (R) 2-32(S) H H CH 2 CH 3 2029 (S) 160.5 (S) 2-32(R,S) human H H CH 2 CH 3 13.60 (R,S), Human 2-32(R) human H H CH 2 CH 3 6.668 (R), Human 2-33 H H CH 2 CH 3 1-Adamantyl 11.93 4.804 2-33 H H CH 2 CH 3 1-Adamantyl 2.321 human Human 2-34(R,S) H H CH 2 CH 3 2.889 (R,S) 3.345 (R,S) 2-34(R) H H CH 2 CH 3 1.573 (R) 1.558 (R) 2-34(S) H H CH 2 CH 3 14.17 (S) 6.789 (S) 2-34(R,S) human H H CH 2 CH 3 2.488 Human 2-35 H H CH 2 CH 3 14.36 20.93 2-36 H H CH 2 CH 3 133.1 8.532 2-37 H H CH 2 CH 3 3541 836.6 2-38 H H CH 2 CH 3 719.3 747.5 2-39 H H CH 2 CH 3 41.44 19.53 2-40 H H CH 2 CH 3 28.65 14.54 2-41 H H CH 2 CH 3 157.8 159.7 2-42 H H CH 2 CH 3 421.4 147.2 2-43 H H CH 2 CH 3 8816 1858 2-44 H H CH 2 CH 3 16.94 7.037 2-45 H H CH 2 CH 3 418.5 15.82 2-46 H H CH 2 CH 3 338.7 15.41 2-47 H H CH 2 CH 3 240.2 18.76 2-48 H H CH 2 CH 3 390.0 47.17 2-49 H H CH 2 CH 3 29.07 18.63 2-50 H H CH 2 CH 3 2-51 H H CH 2 CH 3 2-52 H H CH 2 CH 3 2-53 H H CH 2 CH 3
Preparation of Compounds:
The above materials were generally prepared following Scheme 1 with the exception that N-methyl-2-piperidinemethyl chloride is used in place of acetoxylalkylhalides for the alkylation of the indole 1-position.
When Z=NO 2 , the structures can be transformed to different substituents using methods outlined in Scheme 2.
The commercially unavailable R3-COCl used in Scheme 1 can be prepared according to Scheme 3.
After these acid chlorides are connected at the indole 3-position, the nitro group therein can be further transformed into amino, iodo, azido, and isothiocyanate groups according to the methods outlined in Scheme 4.
Examples of specific analogs were prepared as follows:
1-(N-Methyl-2-piperidinyl)methyl-3-(3-quinolinecarbonyl)-1H-indole
To the suspension of 200 mg (1.5 mmol) of anhydrous AlCl 3 in 8 ml absolute methylene chloride was added 287.4 mg (1.5 mmol) 3-quinolinecarbonyl chloride in 5 ml methylene chloride and the reaction mixture was stirred 30 min at room 22-25° C. The (N-Methyl-2-piperidinyl)methyl-1H-indole 228.3 mg (1.0 mmol) in 5 ml of methylene chloride was added by dropwise during 1.5 h and the mixture stirred 36 h. The reaction was work-up by addition of 20 ml 2M solution of sodium hydroxide and extracted by ethyl acetate (3×20 ml). The combined extract dried by sodium sulfate. After removing of solvents the rest (0.365 g) was purified by chromatography (silica gel, toluene-triethylamine, 10:1).
1-(N-Methyl-2-piperidinyl)methyl-3-(1-adamantanecarbonyl)-1H-indole
To the stirring solution of the diethyl aluminum chloride (1.5 ml 1 M soln. in hexane, 180.8 mg, 1.5 mmol) in 10 ml absolute methylene chloride was added at room temp. 298.0 mg (1.5 mmol) 1-adamantanecarbonyl chloride in 5 ml of methylene chloride and the reaction mixture was stirred 15 min. The solution of (N-Methyl-2-piperidinyl)methyl-1H-indole (228.3 mg, 1.0 mmol) in 5 ml of methylene chloride was added during 3 min and mixture was stirred and reflux 48 h. The reaction was work-up by addition of 20 ml 2M solution of sodium hydroxide and extracted by ethyl acetate (3×20 ml), washed to times by water and two times by brine. The combined extract dried by the mixture of sodium sulfate and potassium carbonate. After removing of solvents the rest was purified by chromatography (silica gel, methanol ethyl acetate 1:1).
1-(N-Methyl-2-piperidinyl)methyl-3-(2-iodo-5-cyano)benzoyl-1H-indole
1-(N-Methyl-2-piperidinyl)methyl-3-(2-iodo-5-amino)benzoyl-1H-indole (111.6 mg, 0.236 mmol) was dissolved in 3 ml of water containing 43 mg (1.179 mmol) of hydrogen chloride (101 mkl 38% HCl in 3 ml H 2 O). The this solution was added at stirring sodium nitrite 16.64 mg (0.241 mmol) in 1 ml of water at 0° C. After 1 h the obtained diazonium salt was gradually added to solution of cuprous cyanide (23.5 mg, 0.264 mmol) in sodium cyanide (28.25 mg (0.528 mmol) in 1 ml of water at 60° C. The reaction mixture was diluted by water, extracted ethyl acetate (3×15 ml), dried sodium sulfate and after removing of solvent purified by chromatography (silica gel, methanol-ethyl acetate, 1:2).
A person of ordinary skill in the art, understanding the disclosures for the general preparation and specific preparation examples would know how to modify the disclosed procedures to achieve the above listed analogs.
The prepared cannabinoid compounds were tested for CB2 receptor binding affinity and for CB1 receptor affinity (to determine selectivity for the CB2 receptor). As used herein, “binding affinity” is represented by the IC 50 value which is the concentration of an analog required to occupy the 50% of the total number (Bmax) of the receptors. The lower the IC 50 value, the higher the binding affinity. As used herein a compound is said to have “binding selectivity” if it has higher binding affinity for one receptor compared to the other receptor; e.g. a compound that has an IC 50 of 0.1 nM for CB1 and 10 nM for CB2, is 100 times more selective for the CB1 receptor. The binding affinities (K i ) are expressed in nanomoles (nM).
For the CB1 receptor binding studies, membranes were prepared from rat forebrain membranes according to the procedure of P. R. Dodd et al; A Rapid Method for Preparing Synaptosomes: Comparison with Alternative Procedures , Brain Res., 107-118 (1981). The binding of the novel analogues to the CB1 cannabinoid receptor was assessed as described in W. A. Devane et al; Determination and Characterization of a Cannabinoid Receptor in a Rat Brain , Mol. Pharmacol., 34, 605-613 (1988) and A. Charalambous et al; “5′-azido Δ 8 -THC: A Novel Photoaffinity Label for the Cannabinoid Receptor”, J. Med. Chem., 35, 3076-3079 (1992) with the following changes. The above articles are incorporated by reference herein.
Membranes, previously frozen at −80° C., were thawed on ice. To the stirred suspension was added three volumes of TME (25 mM Tris-HCl buffer, 5 mM MgCl 2 and 1 mM EDTA) at a pH 7.4. The suspension was incubated at 4° C. for 30 min. At the end of the incubation, the membranes were pelleted and washed three times with TME.
The treated membranes were subsequently used in the binding assay described below. Approximately 30 μg of membranes were incubated in silanized 96-well microtiter plate with TME containing 0.1% essentially fatty acid-free bovine serum albumin (BSA), 0.8 nM [ 3 H] CP-55,940, and various concentrations of test materials at 30° C. for 1 hour. The samples were immediately filtered using a Packard Filtermate 196 and Whatman GF/C filterplates and washed with wash buffer (TME) containing 0.5% BSA. Radioactivity was detected using MicroScint 20 scintillation cocktail added directly to the dried filterplates, and the filterplates were counted using a Packard Instruments Top-Count. Nonspecific binding was assessed using 100 nM CP-55,940. Data collected from three independent experiments performed with duplicate determinations was normalized between 100% and 0% specific binding for [ 3 H] CP-55,940, determined using buffer and 100 nM CP-55,940. The normalized data was analyzed using a 4-parameter nonlinear logistic equation to yield IC 50 values. Data from at least two independent experiments performed in duplicate was used to calculate IC 50 values which were converted to K i values using the using the assumptions of Cheng et al; “Relationship Between the Inhibition Constant (K i ) and the concentration of Inhibitor which causes 50% Inhibition (IC 50 ) of an Enzymatic Reaction”, Biochem. Pharmacol., 22, 3099-3102, (1973), which is incorporated by reference herein.
For the CB2 receptor binding studies, membranes were prepared from frozen mouse spleen essentially according to the procedure of P. R. Dodd et al; “A Rapid Method for Preparing Synaptosomes: Comparison with Alternative Procedures”, Brain Res., 226, 107-118 (1981) which is incorporated by reference herein. Silanized centrifuge tubes were used throughout to minimize receptor loss due to adsorption. The CB2 binding assay was conducted in the same manner as the CB1 binding assay. The binding affinities (K i ) were also expressed in nanomoles (nM). The structures, binding affinities and selectivities are summarized in Table 1.
As can be seen from the results in TABLES 1 and 2, some of the compounds, for example, 2-7, show a high selectivity for the CB2 receptor. The compounds described herein have high potential when administered in therapeutically effective amounts for providing a physiological effect useful to treat a variety of disease conditions. Naturally, the disclosure also encompasses any physiologically acceptable salts, diasteromers, enantiomers, double bond isomers and mixtures of the above disclosed compounds.
In addition, some of the iodide and fluoride containing compounds, for example, 2-7 or 2-24, are potential radioactive probes which would be useful for imaging in vivo the distribution of cannabinoid receptors. Further, azido containing compounds would be useful as affinity probes for characterizing binding pockets of cannabinoid receptors.
While preferred embodiments of the foregoing have been set forth for purposes of illustration, the foregoing description should not be deemed a limitation of the disclosure herein. Accordingly, various modifications, adaptations and alternatives may occur to one skilled in the art without departing from the spirit and scope of the present disclosure. | Disclosed are cannabimimetic aminoalkylindole compounds and methods for their manufacture. The disclosed compounds are surprisingly potent and selective cannabinoids. The disclosed compounds may include radioactive atoms. Also disclosed are methods of using the disclosed compounds, including use of the disclosed compounds to stimulate a cannabinoid receptor, to provide a physiological effect in an animal or individual, to treat a condition in an animal or individual and for use in radioimaging. | 2 |
RELATED APPLICATIONS
[0001] This application is a continuation in part of U.S. Ser. No. 10/952,530, filed Sep. 28, 2004, which claims priority from U.S. Provisional Patent Application Ser. No. 60/507,593, filed Oct. 1, 2003.
FIELD OF THE INVENTION
[0002] This invention relates generally to compositions and methods useful in the prevention and treatment of osteoporosis and for bone and fracture repair. More specifically, the invention relates to slow-releasing calcium phosphate-based materials incorporating Mg, Zn, F, carbonate and optionally other ions such as, for instance, boron, strontium, manganese, copper, silicate, etc. or organic moieties such as, for instance, proteins, amino acids, nutraceuticals, etc. that may promote bone formation and inhibit bone resorption.
BACKGROUND OF THE INVENTION
[0003] Osteoporosis is a progressive and debilitating metabolic bone disease characterized by low bone mass (bone loss) and structural deterioration (thinning of the cortical bone and disorganization of the trabecular bone) leading to increased bone fragility and susceptibility to fractures especially of the hip (femoral head), spine (vertebrae) and the wrist. Osteoporosis is a ‘silent’ disease because related bone loss occurs without symptoms until the individual suffers a bone fracture. Worldwide, the number of hip fractures due to osteoporosis was projected to rise from 1.7 million in 1990 to 6.3 million by 2050. In the U.K., it was estimated that the National Health Service cost associated with osteoporosis is over L600 million ($1.02 billion) per year in 1991 and projected to increase considerably. In Japan, estimated number of hip fracture in 1998 was about 90,000/year with associated hospital cost of about $120 million per year. In the U.S., osteoporosis is responsible for more than 1.5 million fractures/year including: 300,000 hip fractures and approximately 700,000 vertebral fractures, 200,000 wrist fractures and 300,000 fractures in ribs and other sites. 12% to 20% of patients with hip fracture die within a year after the fracture, usually from complications related to either the fracture or surgery. In 2001, the estimated health care cost (hospitals and nursing homes) related to osteoporosis and associated fractures were $17 billion ($47 million/day!) and projected to increase to $30 to $40 billion annually in the next decade.
[0004] Bone tissue consists of two types: cortical (or compact bone) and trabecular (or spongy bone), differing in architecture, properties and function. The cortical bone provides mechanical strength and protective functions while cancellous or trabecular bone provides the metabolic functions. Two major processes are responsible for the development and maintenance of the bone tissue: bone formation (bone build-up) and bone resorption (bone modeling). During skeletal development in humans (birth to adulthood), the rate of bone formation is much greater than the rate of bone resorption until maximum bone mass (peak bone mass) is reached (at about age 35 for cortical bone and earlier for trabecular bone). After the peak bone mass is reached, the bone turnover per year is about 25% in trabecular bone and 3% in cortical bone. A bone remodeling process (bone turnover) in which the rates of bone formation and bone resorption are equal in the same site maintains the skeletal mass in adulthood. When these two processes are in equilibrium or are “coupled,” there is no net gain or loss in bone mass. It is believed that the bone loss associated with primary type of osteoporosis results from the uncoupling of these two processes; with the rate of bone formation being much lower than the rate of resorption. A secondary type of osteoporosis is observed after prolonged immobilization and prolonged periods of bed rest or under glucocorticoid treatment for pulmonary disorders. In such conditions the mechanism of bone loss include both increased bone resorption and decreased bone formation. Reduction in bone formation leads to inadequate bone replacement during remodeling and to gradual bone loss resulting in the thinning of the cortical bone and reduction in cancellous bone formation.
[0005] Two major bone cells are involved—osteoblasts for bone formation and osteoclasts for bone resorption. Bone formation is reflected in osteoblast activities involving matrix (collagen, protein, DNA) formation and mineralization. Bone resorption is determined by the rate of osteoclast recruitment and the intensity of osteoclast activity manifested by the appearance of resorption pits. Most conditions leading to osteoporosis (including estrogen deficiency, hyperparathyroidism and hyperthyroidism) are associated with increased osteoclastic bone resorption and the inability of the bone formation process to keep up with the resorption process.
[0006] Bone is a composite of about 25 wt % biopolymer (organic matrix), 70 wt % mineral or inorganic phase, and 5 wt % water. The organic matrix is principally (about 95%) of Type I collagen with non-collageneous proteins. Osteoporosis is characterized by bone loss, decreased bone strength, lower bone density, poorer bone quality (e.g., porous cortical bone), thinning cortical bone and disorganized trabecular bone. Bone loss is often a predictor of future fracture risk.
[0007] In bone resorption, dissolution of the bone mineral occurs before the degradation of the collagen fibers. The rate of osteoclastic destruction of mineralized tissues was observed to be inversely proportional to bone mineral density. The bone mineral or inorganic component of bone is a calcium phosphate idealized as a calcium hydroxyapatite, Ca 10 (PO 4 ) 6 (OH) 2 . However, comprehensive studies on synthetic and biologic apatites demonstrate convincingly that biologic apatites (mineral phases of enamel, dentin, cementum and bone) are apatites containing minor constituents (carbonate and magnesium) and are more accurately described as carbonate hydroxyapatite, approximated by the formula, (Ca,Na,Mg) 10 (PO 4 ,HPO 4 ,CO 3 ) 6 (OH) 2 . Changes in the composition of the apatite affect its lattice parameters, morphology, crystallinity (reflecting crystal size and/or perfection) and dissolution properties. For example, Mg-for-Ca or CO 3 -for-PO 4 substitution decreases crystallinity (crystal size) and increases solubility while F-for-OH substitution increases crystal size and decreases the solubility of synthetic apatites.
[0008] Osteoporotic bones were observed to have lower magnesium (Mg) and carbonate (CO 3 ) concentrations. Along with decreased Mg and CO 3 contents, larger bone apatite crystals (based on infrared spectroscopic measurements of ‘crystallinity index’) were reported in bones from patients with postmenopausal osteoporosis and alcoholic osteoporosis. Smaller bone apatite crystals were observed in bones of rats fed excess Mg while bone apatite crystals increased in size in bones from Mg-deficient rats. Enamel crystals of rats injected with Mg were smaller than those of the controls. On the other hand, bone apatite crystals from rats drinking high levels of fluoride (F) were larger and less soluble. Increase in width of bone apatite crystals were also observed in the bones of F-treated rabbits. Larger enamel apatite crystals in rat's teeth were observed after F administration.
[0009] Although there is still no known cure for osteoporosis, some medications have been approved by the FDA for postmenopausal women to prevent and/or treat osteoporosis. These include biphosphonates such as alendronate (Fosamax) and Risedmate (Actonel), Calcitonin (e.g., Miacalcin), estrogen (e.g., Climara, Estrace, Estraderm, Estratab, Ogen, Orto-Es, Viovlle, Premarin, etc) and hormones (estrogens and progestins (e.g., Activella, FemJHrt, Premphase, Prempro, etc); and selective estrogen receptor modulators, SERMs such as ralozifene (Evista). Sodium fluoride (NaF) treatment is pending approval. Treatments under investigation include parathyroid hormone (PTH), vitamin D metabolites, other biphosphonates, and SERMs. These therapeutic agents, except F therapy, are described as anti-resorptive agents because they principally target bone resorption. These therapeutic agents are associated with some serious side effects. For example, estrogen therapy is associated with cancer while bisphosphonate-based drugs are associated with osteonecrosis of the jaw and delayed healing.
[0010] Currently, experimental fluoride compounds recommended for osteoporosis therapy include sodium fluoride (NaF), monosodiumfluorophosphate, MFP, (Na 2 PO 3 F) and slow release preparation of NaF (SR—NaF). There is general agreement that F stimulates bone formation directly without the need for prior bone resorption and that it is this uncoupling of resorption and formation that makes this element so effective in increasing bone mass. However, fluoride therapy has also been associated with increased fracture risk despite increased bone mass.
[0011] The bone mineral can best be described as a carbonate hydroxyapatite, approximated by the formula: (Ca,Na,Mg) 10 (PO 4 ,CO 3 ,HPO 4 ) 6 (OH,Cl) 2 containing about 40% calcium. Calcium is stored in bone in the process of mineralizing newly deposited tissue and it is withdrawn from bone only by resorption of old bone tissue. The biological fluids are metastable with respect to apatite, maintaining the integrity of the bone and tooth mineral (apatite). Ca deficiency in the diet induces osteoporosis in rats. Ca supplementation is strongly recommended for optimum bone health. Ca supplementation has been reported to reduce cortical bone loss during the first 5 years of menopause and produce a sustained reduction in the rate of total body bone loss at least 3 years after menopause. However, by itself, Ca supplementation does not appear to slow the rapid loss of trabecular bone during the first few years of menopause nor does it prevent the menopause-related lumbar bone loss. A study on spinal bone loss in postmenopausal women supplemented with Ca and trace minerals (zinc, manganese and copper) showed that bone loss was arrested by intake of Ca plus trace minerals while no difference was observed between the placebo group or group receiving Ca alone.
[0012] Magnesium (Mg) is an important element in biological systems. 50% to 60% of Mg in the body is associated with the bone mineral. The rest of the Mg in the body is intracellular, a required co-factor in more than 300 enzyme systems. Mg is critical for cellular functions that include oxidative phosphorylation, glycolysis, DNA transcription and protein and nucleic acid synthesis. Mg deficient diet in rats was shown to have impaired bone growth (reduction in bone formation and bone volume), decreased bone strength and increased fragility. These and other animal studies implicate Mg deficient diet as a possible risk factor for osteoporosis. In humans, Mg deficiency in the diet was also associated with osteoporosis. Mg therapy was reported to increase bone mass in postmenopausal osteoporosis. Other studies suggest that Mg supplementation suppresses bone turnover rates in young adult males. On the cellular level, in vitro, an isolated report indicates that Mg directly stimulated osteoblast proliferation.
[0013] Zn is an essential trace element in the activity of more than 300 enzymes and affects basic processes of cell division, differentiation, and development and is required in collagen biosynthesis and in the biosynthesis and repair of DNA, in matrix and protein synthesis and plays an important role in bone metabolism and growth. It is the most abundant trace metal in bone mineral, being present at a concentration of up to 300 ppm. Zn deficiency in rats was shown to result in a 45% reduction in cancellous bone mass and to a deterioration of trabecular bone architecture, with fewer and thinner trabeculae and therefore may be considered as a risk factor in the development of osteoporosis. In vivo, Zn was shown to stimulate bone formation in weanling rats and in aged rats.
[0014] On the cellular level in vitro, Zn has been shown to have a stimulatory effect on bone formation and an inhibitory or biphasic effect on osteoclastic bone resorption. Studies on Zn-releasing compounds such as b-alanyl-L-histadanato zinc and Zn-TCP demonstrated that Zn promoted greater bone formation in vitro and was effective in increasing bone density or in preventing bone loss in vivo.
[0015] On the crystal level in synthetic systems, the presence of Zn causes the formation of apatite with low crystallinity, promoting the formation of Zn-substituted .β-TCP or even amorphous calcium phosphate (ACP), depending on the solution Zn/Ca molar ratio. Both Mg and Zn were shown to inhibit the growth of apatite.
[0016] The relevant literature suggests that Mg or Zn separately may have beneficial effects on bone matrix but may cause the formation of bone apatite with low crystallnity (small crystal size). On the other hand, F may improve crystallinity (larger crystal size) and reduce solubility of bone apatite, but may cause impaired or abnormal mineralization. Separately, Mg, Zn and F ions have been associated with promotion of osteoblastic activity (bone formation) and/or inhibition of osteoclastic activity (bone resorption). Zn-releasing compounds, such as b-alanyl-l-histadano zinc compounds and Zn-TCP have been shown to have therapeutic effect on osteoporosis in rats induced by zinc-deficiency. Mg and Zn deficiencies have been reported as risk factors for osteoporosis. F compounds (NaF, monofluorophosphate and slow-releasing NaF) are used in the management of osteoporosis.
SUMMARY OF THE INVENTION
[0017] The present invention provides novel biomaterials comprising one or more of the following ions: magnesium (Mg), zinc (Zn) and fluoride (F) ions in a carbonate-containing apatite or biphasic calcium phosphate, BCP system. The present invention may consist of carbonate apatite and tricalcium phosphate incorporating Mg, Zn, F or other ions. In some embodiments, the biomaterial contains Mg, in some embodiments Zn, in some embodiments F, in some embodiments Mg and Zn, in some embodiments Mg and F, in some embodiments Zn and F, and in some embodiments Mg, Zn and F. In some embodiments, the biomaterial may contain one or more additional ions, for instance, strontium, boron, manganese, copper, silicate, etc. In yet other embodiments, the biomaterial may contain one or more additional compounds, such as, for instance, nutraceuticals that have anti-inflammatory, antibacterial or anti-oxidant properties or activity. In still further embodiments, the biomaterial may contain one or more additional protein or peptide. In preferred embodiments, the biomaterial is substantially free of serious side effects or deleterious effects on bone strength and fracture incidence such as those associated with the presently FDA-approved anti-resorptive agents. The biomaterial may be substantially similar in composition to bone mineral (a carbonate apatite). In some embodiments, the biomaterial features slow release of Mg, Zn, F, Ca, and P ions. In other embodiments, the biomaterial combines ions in preferred concentrations known separately to promote bone formation and minimize or prevent bone resorption. In yet other embodiments, the biomaterial allows the incorporation of lower levels of these ions thus avoiding deleterious effects observed with higher levels. In still other embodiments, the biomaterial provides beneficial effects of Mg and Zn on collagen and protein formation to balance the F effect on bone apatite formation and crystal size thereby promoting formation of bone with higher mineral density and greater bone mass. In yet other embodiments, the biomaterial provides synergistic effects of the three elements on bone resorption to allow the rate of bone formation to catch up with the rate of bone resorption, resulting in a net gain in bone mass. The biomaterials of the present invention may be useful for reducing the development of osteoporosis or even preventing osteoporosis, increasing cancellous bone mass and arresting the progress of osteoporosis, reversing bone loss and repairing fractures such as those caused by osteoporosis. The biomaterials may also be used in treating other bone deficiency caused by mineral deficiency or diseases such as cancer or osteopenia or therapies such as steroid treatments or radiation or conditions such as immobilization).
[0018] The biphasic calcium phosphate, BCP, may be, in one embodiment, a mixture of unsubstituted hydroxyapatite (HA) or substituted HA or substituted carbonate apatite and unsubstituted β-TCP, Ca 3 (PO 4 ) 2 or substituted β-TCP. BCP of varying HA/.β-TCP ratios may be produced directly or by sintering calcium-deficient apatite, for instance having a Ca/P<1.67, that has been prepared either by a precipitation or by a hydrolysis method or by a solid-state reaction.
[0019] In some embodiments, the amount of each component (by weight %) present in the biomaterials of the invention may be as follows: Mg, 0.0.05 to 20 wt %, Zn, 0.02 to 20 wt %, F, 0.0 to 4 wt %, calcium (Ca commonly designated “C” herein as in “TCP” or “BCP”) 10 to 50 wt %, phosphate (commonly designated “P” herein, as in “TCP” or “BCP”) 5 to 30 wt %, carbonate (CO 3 ) 0.5 to 25 wt %. In other embodiments, the amount of each component (by weight %) present in the biomaterials of the invention may be as follows: Mg, 0.05 to 12 wt %; Zn, 0.02 to 12 wt %; F, 0.0 to 4 wt %, calcium (Ca commonly designated “C” herein as in “TCP” or “BCP”), 20 to 40 wt %; phosphate, (commonly designated “P” herein, as in “TCP” or “BCP”) 10 to 20 wt %; carbonate (CO 3 ). 1 to 20 wt %. In some embodiments, the biomaterial contains Ca, P, and CO 3 . The biomaterial may also be combined with one or more organic moieties such as proteins, amino acids, nutraceuticals with antibacterial, antioxidante and anti-inflammatory properties known to inhibit osteoclastic activity or promote osteoblastic activity. The biomaterial may be unsintered or sintered (heated) at temperatures of, for instance, about 200° to 1000° C. The biomaterial may be used as a diet supplement representing from about 0.01 to 5 wt. % of the total diet, or as bone-graft material or scaffold for tissue engineering. The biomaterial may be in any form including: powder, granule, block, in a carrier (e.g., a saline solution or a polymer solution) for injection at local sites, and may be in the form of an injectable cement.
[0020] In a second aspect, the invention provides methods of inhibiting bone resorption by administering a biomaterial comprising one or more of Mg, Zn and F ions in a carbonate-containing apatite or in a biphasic calcium phosphate (BCP) system. In some embodiments, the biomaterial contains Mg, in some embodiments Zn, in some embodiments F, in some embodiments Mg and Zn, in some embodiments Mg and F, in some embodiments Zn and F, and in some embodiments Mg, Zn and F. In some embodiments, the biomaterial may contain one or more additional ions, for instance, strontium, boron, manganese, copper, silicate, etc. In yet other embodiments, the biomaterial may contain one or more additional compounds such as, for instance, nutraceuticals that have anti-oxidant, anti-inflammatory or antibacterial properties or activity. In still further embodiments, the biomaterial may contain one or more additional proteins or peptides. The biomaterial may be substantially similar in composition to bone mineral (a carbonate apatite). In some embodiments, the biomaterial features slow release of Mg, Zn, F, Ca, and P ions. The biphasic calcium phosphate, BCP, may be, in one embodiment, a mixture of unsubstituted hydroxyapatite (HA) or substituted HA or substituted carbonate apatite and unsubstituted β-TCP, Ca 3 (PO 4 ) 2 or substituted β-TCP. BCP of varying HA/.β-TCP ratios may be produced directly or by sintering calcium-deficient apatite, for instance having a Ca/P<1.5, 1.6, 1.67, 1.75 or 1.8 that has been prepared either by a precipitation or by a hydrolysis method or by a solid-state reaction. In some embodiments, the amount of each component (by weight %) present in the biomaterials of the invention may be as follows: Mg 0.5 to 12 wt %, Zn 1 to 12 wt %, F 0.1 to 4 wt %, calcium (Ca commonly designated “C” herein as in “TCP” or “BCP”) 20 to 40 wt %, phosphate (commonly designated “P” herein, as in “TCP” or “BCP”) 10 to 20 wt %, carbonate (CO 3 ) 1 to 20 wt %. In some embodiments, the biomaterial contains Ca, P, and CO 3 . The biomaterial may also be combined with one or more organic moieties such as moieties known to inhibit osteoclast activity. The biomaterial may be unsintered or sintered at 100 to 1000° C. The biomaterial may be used as a diet supplement or as bone-graft material or scaffold for tissue engineering. The biomaterial may be in any form including: powder, granule, a block, in a carrier (e.g., a saline solution or a polymer solution) for injection at local sites, and may be in the form of an injectable cement.
[0021] In a third aspect, the invention provides methods of treating osteoporosis or delaying the onset of osteoporosis by administering a biomaterial comprising one or more of Mg, Zn and F ions in a carbonate-containing apatite or biphasic calcium phosphate (BCP) system consisting of carbonate apatite and substituted β-TCP. In some embodiments, the biomaterial contains Mg, in some embodiments Zn, in some embodiments F, in some embodiments Mg and Zn, in some embodiments Mg and F, in some embodiments Zn and F, and in some embodiments Mg, Zn and F. The biomaterial may be substantially similar in composition to bone mineral (a carbonate apatite). In some embodiments, the biomaterial may contain one or more additional ions, for instance, strontium, boron, manganese, copper, silicate etc. In yet other embodiments, the biomaterial may contain one or more additional compounds that have anti-oxidant, anti-inflammatory, antibacterial, anti-oxidant properties or activity such as, for instance, a nutraceutical. In still further embodiments, the biomaterial may contain one or more additional protein or peptide. In some embodiments, the biomaterial features slow release of Mg, Zn, F, Ca, and P ions. The biphasic calcium phosphate, BCP, may be, in one embodiment, a mixture of unsubstituted hydroxyapatite (HA) or substituted HA or substituted carbonate apatite and unsubstituted β-TCP, Ca 3 (PO 4 ) 2 or substituted β-TCP. BCP of varying HA/.β-TCP ratios may be produced directly or by sintering calcium-deficient apatite, for instance having a Ca/P<1.5, 1.6, 1.67, 1.75 or 1.8 that has been prepared either by a precipitation or by a hydrolysis method or by a solid-state reaction. In some embodiments, the amount of each component (by weight %) present in the biomaterials of the invention may be as follows: Mg 0.5 to 12 wt %, Zn 1 to 12 wt %, F 0.1 to 4 wt %, calcium (Ca commonly designated “C” herein as in “TCP” or “BCP”) 20 to 40 wt %, phosphate (commonly designated “P” herein, as in “TCP” or “BCP”) 10 to 20 wt %, carbonate (CO 3 ) 1 to 20 wt %. In some embodiments, the biomaterial contains Ca, P, and CO 3 . The biomaterial may also be combined with one or more organic moieties such as moieties known to inhibit osteoclastic activity or promote osteoblastic activity. The biomaterial may be unsintered or sintered (heated) at temperatures of from about 100° to 1000° C. The biomaterial may be used as a diet supplement or as bone-graft material or scaffold for tissue engineering. The biomaterial may be in any form including a powder, granule, a block, in a carrier (e.g., a saline solution or a polymer solution) for injection at local sites, and may be in the form of an injectable cement.
[0022] In a fourth aspect, the invention provides methods of treating a bone fracture by administering a biomaterial comprising one or more of Mg, Zn and F ions in a carbonate-containing apatite or in a biphasic calcium phosphate (BCP) system. In some embodiments, the biomaterial contains Mg, in some embodiments Zn, in some embodiments F, in some embodiments Mg and Zn, in some embodiments Mg and F, in some embodiments Zn and F, and in some embodiments Mg, Zn and F. In some embodiments, the biomaterial may contain one or more additional ions, for instance, strontium, boron, manganese, etc. In yet other embodiments, the biomaterial may contain one or more additional compounds that have anti-oxidant properties or activity. In still further embodiments, the biomaterial may contain one or more additional protein or peptide. The biomaterial may be substantially similar in composition to bone mineral (a carbonate apatite). In some embodiments, the biomaterial features slow release of Mg, Zn, F, Ca, and P ions. The biphasic calcium phosphate, BCP, may be, in one embodiment, a mixture of unsubstituted hydroxyapatite (HA) or substituted HA or substituted carbonate apatite and unsubstituted and substituted β-TCP, Ca 3 (PO 4 ) 2 . BCP of varying HA/β-TCP ratios may be produced directly or by sintering calcium-deficient apatite, for instance having a Ca/P<1.5, 1.6, 1.67, 1.75 or 1.8 that has been prepared either by a precipitation or by a hydrolysis method or by a solid-state reaction. In some embodiments, the amount of each component (by weight %) present in the biomaterials of the invention may be as follows: Mg, 0.05 to 12 wt %; Zn, 0.01 to 12 wt %; F, 0.0 to 4 wt %; calcium (Ca commonly designated “C” herein as in “TCP” or “BCP”), 20 to 40 wt %; phosphate (commonly designated “P” herein, as in “TCP” or “BCP”), 10 to 20 wt %; carbonate (CO 3 ), 1 to 20 wt %. In some embodiments, the biomaterial contains Ca, P, and CO 3 . The biomaterial may also be combined with one or more organic moieties such as proteins, peptides or nutraceuticals with antibacterial, antioxidant, anti-inflammatory properties known to inhibit osteoclastic activity or promote osteoblastic activity. The biomaterial may be unsintered or sintered (heated) at temperatures from about 100° to 1000° C. The biomaterial may be used as a diet supplement or as bone-graft material or scaffold for tissue engineering. The biomaterial may be in any form including a powder, granule, a block, in a carrier (e.g., a saline solution or a polymer solution) for injection at local sites, and may be in the form of an injectable cement.
[0023] In a fifth aspect, the invention provides methods of inhibiting osteoclast activity by administering a biomaterial comprising one or more of Mg, Zn and F ions in a carbonate-containing apatite or in a biphasic calcium phosphate (BCP) system consisting of carbonate apatite and substituted β-TCP. In some embodiments, the biomaterial contains Mg, in some embodiments Zn, in some embodiments F, in some embodiments Mg and Zn, in some embodiments Mg and F, in some embodiments Zn and F, and in some embodiments Mg, Zn and F. In some embodiments, the biomaterial may contain one or more additional ions, for instance, strontium, boron, manganese, copper, silicate, etc. In yet other embodiments, the biomaterial may contain one or more additional compounds such as, for example a neutraceutical that may have anti-oxidant, anti-inflammatory or antibacterial properties. In still further embodiments, the biomaterial may contain one or more additional protein or peptide. The biomaterial may be substantially similar in composition to bone mineral (a carbonate apatite). In some embodiments, the biomaterial features slow release of Mg, Zn, F, Ca, and P ions. The biphasic calcium phosphate, BCP, may be, in one embodiment, a mixture of unsubstituted hydroxyapatite (HA) or substituted HA or substituted carbonate apatite and unsubstituted and substituted β-TCP, Ca 3 (PO 4 ) 2 . BCP of varying HA/.β-TCP ratios may be produced directly or by sintering calcium-deficient apatite, for instance having a Ca/P<1.5, 1.6, 1.67, 1.75 or 1.8 that has been prepared either by a precipitation or by a hydrolysis method or by a solid-state reaction. In some embodiments, the amount of each component (by weight %) present in the biomaterials of the invention may be as follows: Mg 0.5 to 12 wt %, Zn 1 to 12 wt %, F 0.1 to 4 wt %, calcium (Ca commonly designated “C” herein as in “TCP” or “BCP”) 20 to 40 wt %, phosphate (commonly designated “P” herein, as in “TCP” or “BCP”) 10 to 20 wt %, carbonate (CO 3 ) 1 to 20 wt %. In some embodiments, the biomaterial contains Ca, P, and CO 3 . The biomaterial may also be combined with one or more organic moieties such as moieties known to inhibit osteoclastic activity and promote osteoblastic activity. The biomaterial may be unsintered or sintered (heated) at 100 to 1000° C. The biomaterial may be used as a diet supplement or as bone-graft material or scaffold for tissue engineering. The biomaterial may be in any form including a powder, granule, a block, in a carrier (e.g., a saline solution or a polymer solution) for injection at local sites, and may in the form of an injectable cement.
BRIEF DESCRIPTION OF DRAWINGS
[0024] FIG. 1 shows XRD patterns of precipitated carbonate apatite which has been substituted with ion combinations in accordance with the invention. XRD patterns of precipitated carbonate apatite containing: (A) F, (B) Mg+F; (C) Zn+F; and (D) Mg+Zn+F. The differences in the sharpness of the diffraction peaks (line broadening) at about 25.8° 2Θ reflect the difference in their crystallite size. Mg and Zn have additive effects on reducing crystallinity of apatite (B & C vs D).
[0025] FIG. 2 shows XRD patterns of Mg/Zn/F—CaP: (A) before and after sintering (B) at 600° C.; and (C) at 800° C. T=Mg- and Zn-substituted .β-TCP; H═F-substituted apatite.
[0026] FIG. 3 shows dissolution reflected by the release of Ca 2+ ions with time from the synthetic calcium phosphates: (A) F—CaP; (B) Zn/F—CaP; (C) Mg/F—CaP and (D) Mg/Zn/F—CaP.
[0027] FIG. 4 shows dissolution reflected by release of Ca 2+ ions with time of Mg/Zn/F—CaP: before (C, D) and after ignition at 600° C. (B) and at 800° C. (A). C and D have similar concentrations of Mg and Zn but different concentrations of F, with (D) having the lower F concentration. The initial dissolution rate is decreased with increasing sintering temperature (A and B vs. C and D) and with increasing F concentration (A vs. B, C vs. D).
[0028] FIG. 5 shows the enhancing effect of MZF-CaPs on the proliferation of human osteoblast-like cells (MG-63) compared to control.
[0029] FIG. 6 shows the effect of MZF-CaPs on the phenotype expression of bone growth markers by the osteoblast-like cells (MG-63). Bone markers expressed are: osteocalcin (OSC), alkaline phosphatase (AP), collagen type 1 (Col 1), osteopontin (OSP).
[0030] FIG. 7 shows the effect of BCPs on expression of proteoglycans (versican, deconsin, biglycan) by human osteoblast cells.
[0031] FIG. 8 shows XRD profiles (A,B,C,D) and FT-IR spectra (E). XRD profiles: (A) F—CaP; (B) Mg—CaP; (C) Zn—CaP; (D 1 ,D 2 ) MZF-CaPs compared to that of (D 3 ) bone. When Mg or Zn concentrations in the CaP is higher than 5 wt %, two phases are observed: apatite and Mg- or Zn-TCP (C). FT-IR spectra: (EC, EB) MZF-CaPs compared to that of rat bone (EA), showing that the matrix of MZF-CaPs (EC,EB) is a carbonate apatite similar to bone (EA).
[0032] FIG. 9 shows dissolution expressed as release of Ca 2+ ions with time from: (A) F—CaP containing high and low concentrations of F; (B) Mg-TCP; and (C) Zn-TCP. (B) and (C) contain different levels of Mg or Zn, respectively. Dissolution rates of Mg-TCP and Zn-TCP decrease with increasing Mg (B) or Zn (C) and dissolution rate of F—CaP decreases with increasing F (A).
[0033] FIG. 10 demonstrates that Zn-TCP compared to β-TCP, suppressed the activity of mature osteoclasts through: (A) reduction in actin ring formation, (B) down-regulation of CAII and cathepsin K expressions without significant change in the expression of TRAP, and (C) increased cell apoptosis, in a dose dependent manner.
[0034] FIG. 11 represents bone fracture strength of femur of rats on (A) basic diet; (B) mineral deficient (MD)diet; on MD supplemented with: (C) Mg—CaP; (D) Zn—CaP; (E) F—CaP; and (F) MZF-CaP. Bone strength was significantly reduced by mineral deficient (MD) diet (B vs. A) and improved by the MZF-CaP supplemented diets (C,D,E,F vs. B).
[0035] FIG. 12 shows SEM images of cortical bone from rat on: ( 12 A) normal diet; ( 12 B) mineral deficient (MD) diet; ( 12 C, 12 D, 12 E, 12 F) MD supplemented with Mg—CaP, Zn—CaP, F—CaP and MZF-CaP, respectively. The cortical bone loss induced by MD diet ( 10 B vs 10 A) was prevented by the supplemented diets ( 12 C, 12 D, 12 E, 12 F compared to 12 B).
[0036] FIG. 13 shows SEM images of trabecular bone from rat on: ( 13 A) basic diet; ( 13 B) mineral deficient (MD) diet; ( 13 C, 13 D, 13 E, 13 F) MD diet supplemented with Mg—CaP, Zn—CaP, F—CaP and MZF-CaP, respectively. The trabecular bone loss induced by MD diet ( 13 B vs 13 A) was prevented by the supplemented diets ( 13 C, 13 C, 13 E, 13 F compared to 13 B).
[0037] FIG. 14 depicts bone mineral density, BMD of left and right femurs of (A) non-OVX, (B) OVX, (C) OVX injected with Zn-TCP; and OVX injected with MZF-CaPs (D,E,F,G) Ovariectomy induced reduction in BMD (B vs. A), injection with MZF-CaPs prevented the loss in BMD (D,E,F, G compared to B) ( 14 A) Wistar rats after 12 weeks. ( 14 B) Sprague-Dawley rats after 16 weeks.
[0038] FIG. 15 depicts bone strengths of OVX rats on (A 1 ) basic (BD) for 3 months; (A 2 ) BD, 3 months, then BD+MZF-CaP for 2 additional months; (A 3 ) BD+MZF-CaP for 5 months; and non-OVX on (A 4 ) BD for 5 months; and (A 5 ) BD+MZF for 5 months showing increased bone strength in bones from rats (OVX or non-OVX) on diet supplemented with MZF-CaP.
[0039] FIG. 16 shows microCT images of L-5 vertebra (one slice, 10μ) from: (A) OVX rat on basic diet, 5 months; and (B) OVX rat on basic diet supplemented with MZF-CaP showing prevention of bone loss induced by ovariectomy or estrogen-deficiency ( 16 B vs 16 A).
[0040] FIG. 17 shows microCT images of L-5 vertebra (261 slices, 10μ/slice, standard resolution) of OVX rats on (A) basic diet, and (B) basic diet supplemented with MZF-CaP MZF-CaP increased bone volume, trabecular thickness and decreased bone porosity.
[0041] FIG. 18 depicts the extent of dissolution (expressed as release of Ca 2+ ions with time) of rat bones in acidic buffer (0.1M KAc, pH 6 at 37° C.). The dissolution is lower in bones from OVX and non-OVX rats on a basic diet supplemented with MZF-CaP (B vs. A; D vs. C).
[0042] FIG. 19 shows Faxitron images of the femoral heads from (A) non-ovariectomized rats on a basic diet, (B) ovariectomized rats on a basic diet after two months, and (C) ovariectomized rats on a basic diet for two months then on basic diet supplemented with Mg/Zn/F—CaP supplements for one month. Bone loss induced by ovarietomy (B vs A) was recovered when the diet was supplemented with MZF-CaP was administered for one month (C vs B).
[0043] FIG. 20 shows microCT images of femur head demonstrating further the recovery of bone loss that may be achieved by providing Mg/Zn/F—CaP as a dietary supplement. MicroCT images of femur head of rat: (A) on a basic diet, (B) on a mineral-deficient diet for two months, and (C) on mineral-deficient diet for two months followed by a diet having a Mg/Zn/F—CaP dietary supplement for one month. The bone loss induced by mineral deficiency (B vs A) was recovered by adding MZF-CaP supplement to the mineral-deficient diet for one month (C vs B).
DESCRIPTION OF PREFERRED EMBODIMENTS
[0044] The rationale for incorporating Mg, Zn and F in a carbonate apatite matrix was to combine these ions that had been separately associated with biomineralization in a matrix that is similar to bone mineral. Bone mineral is a carbonate apatite. (LeGeros R Z (1981) Prog Crystal Growth Charact 4:145).
[0045] Preparation of MZF-CaPs. Mg/F—CaP, Zn/F—CaP, Mg/Zn/F—CaP were prepared by a hydrolysis method at 90° C. from solutions with known Mg/Ca, Zn/Ca, CO 3 /P and F/P molar ratios. X-ray diffraction (XRD) analysis confirmed earlier observations on the effect of Mg or Zn on the crystallinity of the apatite ( FIG. 1 ), i.e., Mg or Zn tends to lower the crystallinity of apatite. Sintering at 600° C. increased the crystallinity (crystal size). When the concentration of either Mg or Zn in the CaP is higher than 5 wt %, sintering at 800° C., resulted in the formation of biphasic calcium phosphate, BCP, consisting of a mixture of apatite and Mg- and/or Zn-substituted p-TCP ( FIG. 2C ).
[0046] Composition of MZF-CaPs. Elemental analyses using inductive coupled plasma (ICP) showed that the amount of Mg, Zn or F incorporated in the precipitated apatite depended on the solution concentrations of these ions (Table 1). The crystallinity, composition (Table 1, FIG. 8 ) and dissolution rates (release of ions) of the Mg/Zn/F—CaPs can be adjusted by manipulation of reaction condition, ion concentrations and sintering temperatures.
[0000]
TABLE 1
Composition (wt %) and of MX + ZF—CaP preparations tested in animals
Prep#
Ca
P
Mg
Zn
F
CO 3
Ca/P
Mg/Ca
Zn/Ca
F/P
C/P
XRD*
#51
27.71
16.44
1.10
2.90
1.10
3.24
1.30
0.08
0.06
0.11
0.10
AP
#52
27.57
15.73
0.18
0.01
1.21
4.32
1.38
0.01
0.00
0.13
0.14
AP
#53
26.75
17.74
4.10
0.01
0.05
4.41
1.17
0.25
0.00
0.00
0.13
AP
#54
21.94
14.71
0.16
8.40
0.05
5.48
1.17
0.01
0.19
0.00
0.19
BCP
#68
27.71
16.44
2.70
2.85
2.31
3.62
1.30
0.17
0.06
0.03
0.12
AP
#74
27.19
16.76
2.00
2.24
1.50
3.60
1.26
0.12
0.09
0.15
0.11
AP
#76
28.54
15.98
1.95
2.44
3.00
2.39
1.38
0.11
0.05
0.31
0.08
AP
#86
22.19
13.64
2.26
2.23
1.00
3.69
1.25
0.17
0.06
0.12
0.14
AP
*XRD: AP, apatite; BCP, biphasic calcium phosphate (mixture of Xn-substituted tricalcium phosphate and AP
[0047] Dissolution properties of MZF-CaPs. It has been demonstrated that an acidic microenvironment is fundamental to the resorptive process by the osteoclasts. Therefore, in vitro dissolution properties of the Mg/Zn/F-BCP materials under acidic conditions is predictive of in vivo degradation of these materials. For example. β-TCP shown to be more soluble than HA in vitro and was also shown to have greater degradation in vivo. The rate of release of the essential elements (Mg, Zn and F) obtained in vitro gives an insight into their rate of release in vivo. Incorporation of Mg or Zn increased while incorporation of F decreased extent of dissolution of MZF-CaPs as measured by the Ca release ( FIG. 3 ). The extent of dissolution decreased with increasing sintering temperature and with increasing amount of F ( FIG. 4 ). Maximum release was observed after 10-minute exposure in the acidic buffer (0.1M NaAc, pH 5, 37° C.).
[0048] Results from the in vitro dissolution study of experimental synthetic materials provides information on the rate of release of Mg, Zn, F, Ca and P from the Mg/Zn/F—CaP materials and give insight into their release and availability in vivo. The dissolution is affected by the following factors: composition (the greater the F content, the lower the dissolution rate); sintering temperature (sintered materials have a slower rate of dissolution than uncalcined or unsintered materials), particle size, porosity and surface area and possibly physical form (e.g., powder vs. discs). The slow release of these ions from the Mg/Zn/F-BCP materials avoids the side effects observed for the fast releasing materials such as those reported for NaF.
[0049] Effect of MZF-CaPs on bone cell activities. Bones are constantly being remodeled throughout life. Under normal conditions, bones are being dissolved by osteoclasts and rebuilt by osteoblasts under exquisite regulatory control. In pathologic conditions such as osteoporosis, the tightly controlled bone remodeling process is disrupted and osteoclast activity outpaces bone production by osteoblasts. Laboratory models that can characterize the behavior of osteoclasts and osteoblasts at the cellular and molecular level provide critical insights into the pathophysiology of bone remodeling. In vitro cell models are important tools that address this problem. Osteoblast-like cells that exhibit characteristics of normal osteoblasts including synthesis of bone matrix component: collagen type I, osteocalcin, osteopontin and osteonectin help evaluate the effects of Mg/Zn/F-BCPs on cellular events involved in bone formation. Similarly, osteoclast-like cells derived from the bone marrow help clarify the effect of Mg/Zn/F-BCPs on bone resorption. In vitro cell models have also been instrumental in screening various agents and biomaterials for clinical application in a cost-effective way.
[0050] Results from in vitro studies demonstrated that MZF-CaPs (releasing Ca, P, Mg, Zn and F ions) promoted proliferation, differentiation and phenotypic expression of bone markers and protoglycans by osteoblast-like cells (bone forming) showing stimulation of bone formation (FIGS. 4 , 5 , 6 ). In vitro studies on osteoclasts showed that Zn—CaP (releasing Ca, P and Zn ions) and carbonate-F-apatite (releasing Ca, P and F ions) inhibited osteoclast (bone resorbing) activities ( FIG. 10 ).
[0051] Mg, Zn, F simultaneously present at optimum concentrations in a calcium phosphate system (Mg/Zn/F—CaPs) enhance osteoblast activity (bone formation) as well as inhibit osteoclast activity (bone resorption) in vitro to a greater degree than when present separately. Cell response to materials with combined incorporation of Mg, Zn and F is more favorable than to materials incorporating these ions separately.
[0052] Ovariectomized rat model. Ovariectomized rats have been used as an animal model for postmenopausal bone loss. The justification for this model is the observed similarities between ovariectomy-induced bone loss in rats and postmenopausal bone loss in humans, e.g., increased bone turnover, greater bone resorption than bone formation, greater loss of trabecular bone compared to cortical bone. The ovariectomized rats are given deficient diets to accelerate the onset of osteoporosis. Diet deficiency or immobilization and immobilization and calcium-deficient diet have been associated as risk factors for osteoporosis.
[0053] Prevention of bone loss by MZF-CaP administered as daily an oral supplement. Results of initial studies demonstrated that mineral deficiency or estrogen deficiency (ovariectomy) in a rat model causes bone loss, thinning of cortical and trabecular bone, reduction in trabecular bone density and connectivity ( FIGS. 12 , 13 ) and decrease in bone strength ( FIG. 11 ). All these features are similar to that observed in osteoporotic bone. The newly developed biomaterial, MZF-CaPs or synthetic bone mineral (SBM), when administered as a daily supplement to a mineral deficient diet or administered to OVX rats prevented bone loss in cortical and trabecular bones (FIGS. 12 , 13 , 16 , 17 ) (LeGeros et al, Key Eng Mater 2008; 361-363:43-46; IADR 2006, abstract no. 270; IADR 2007, abstract no. 2176). The bone seeking ions (Mg, Zn and F) in MZFCaP were incorporated in the cortical and trabecular bones (Table 2).
[0000]
TABLE 2
Composition (wt %) of rat cortical bones (not ashed). Phase 1.
Diet
Ca
P
Mg
Zn
F
Basic
26.44
12.121
0.50
0.05
0.02
Mineral deficient (MD)
25.77
11.96
0.26
0.05
0.02
MD + Mg—CaP (#53)
26/14
12/03
0.44
0.05
0.02
MD + Zn—CaP(#54)
25.93
11.78
0.31
0.24
0.02
MD + F—CaP(#52)
25.87
11.62
0.40
0.08
0.21
MD + MZF—CaP (#51)
27.09
12.43
0.45
0.10
0.12
[0054] Prevention of bone loss by MZF-CaP administered by weekly injection. Parallel studies also showed that MZF-CaP administered as a weekly injection for 4, 12 or 16 weeks also increased bone strength ( FIG. 14 ) and prevented bone loss induced by estrogen deficiency (Otsuka et al. J. Pharm Sci 2008; 97:421-432; Key Eng Mater 2006, 254-256:343-346; Tokudome et al., IADR 2006 abstract No. 1138).
[0055] Recovery of bone loss. Current FDA approved drugs have been shown to prevent further bone loss but were not shown to recover or restore bone already lost to the disease (Mohan et al., (1996) In: Principles of Bone Biology Ch 80 Academic Press: New York, pp. 1111-1124). These preliminary results demonstrate that MZF-CaP administered as oral supplement restored bone loss induced by either mineral deficiency or estrogen deficiency (ovariectomy) as shown in FIGS. 19 and 20 .
[0056] Dissolution properties of rat bones. Osteoclastic activity results in bone resorption. Such activity occurs in an acidic invironment. In vitro dissolution (in acidic buffer) rates of bone obtained from animals receiving MZF-CaP supplement were shown to be lower than those from controls (not receiving MZF-CaP supplement untreated) as shown in FIG. 18 . Treatment results in compositional changes in the bone mineral making it less susceptible to acid challenge (bone resorption)
EXAMPLES
[0057] The following examples are provided to further demonstrate particular embodiments of the invention and are not considered to limit the scope of the invention.
Example 1
[0058] Cell response to Mg/Zn/F-BCP materials. Unsintered materials used for studies on in vitro cell response included Mg—CaP, Zn—CaP, F—CaP, Mg/Zn/F—CaP.
[0059] Effect on proliferative capacity of osteoblast-like (bone-forming) cells. The effect on the proliferative capacity of human osteoblast-like cells was studied by incubating human MG-63 (10 5 cells/well/ml) in the presence or absence of materials at 37° C., 5% CO 2 for 5 days. The cells were radiolabeled with 1 mCi of 3 H-thymidine, and the proliferation rate was determined by scintillation counting of TCA precipitable DNA. The materials significantly increased the proliferative capacity of osteoblast-like cells. Higher proliferative effect compared to control in cells exposed to the synthetic materials was observed.
[0060] Effect on phenotype expression of bone growth markers. The effect on the phenotype expression and growth markers of human bone-derived osteoblasts was studied by incubating 10 5 cells/well/ml in the presence or absence of the materials at 37° C., 5% CO 2 for 5 days.
[0061] Total RNA was isolated and specific transcript levels for osteocalcin (OSC), alkaline phosphatase (AP), collagen type I (Col 1), osteopontin (OSP) and growth markers cyclin D1 (CD1) and CDk5 were determined by reverse transcriptase polymerase chain reaction (RT-PCR). The levels of OSC mRNA were low and expression was not detectable in osteoblasts incubated in control medium alone. Incubation with four different preparations enhanced OSC expression to detectable level ( FIG. 5 ). OSC is documented to play a critical role in mineralization.
[0062] FIG. 5 depicts the effect of the present synthetic materials on proliferation of human osteoblast-like cells (MG-63) compared to control. All the materials, especially ( 2 ), ( 4 ), ( 5 ) and ( 6 ) caused increased cell proliferation compared to control. ( 1 ) and ( 6 ) have similar F concentrations, ( 1 ) has lower Mg and Zn concentrations. FIG. 6 shows the effect of the present synthetic materials on the phenotype expression: osteocalcin, OSC; alkaline phosphatase, AP; collagen type I, Col I; and osteopontin, OSP and growth markers: cyclin D1 (CD1) and CDk4. OSC becomes detectable from materials ( 4 ), ( 5 ) and ( 6 ). The expression for OSP is stronger for materials ( 4 ), ( 5 ) and ( 6 ). The materials used for both tests: ( 1 ) Mg/Zn/F—CaPa, ( 2 ) Mg/CHA, ( 3 ) Zn/CHA, ( 4 ) CHA, ( 5 ) CFA, and ( 6 ) Mg/Zn/F—CaPb. ( 1 ) and ( 6 ) have equivalent levels of F and CO 3 , Mg and Zn levels lower in ( 1 ) compared to ( 6 ). The levels of Mg in ( 2 ) and that of Zn in ( 3 ) are equivalent to that in ( 6 ). The levels of F in ( 1 ), ( 4 ) and ( 6 ) are similar and the levels of CO 3 in ( 10 to ( 6 ) are similar. MZF-CaPs also affect the human osteoblasts expression of proteoglycans. Analysis of proteoglycan transcripts showed no distinct pattern in versican expression whereas decorin expression appeared to be modulated by the CaPs. Biglycan expression was profoundly increased by CaPs containing Mg, Zn and F.
Example 2
[0063] Preparation and Characterization of Unsintered and Highly Sintered (Ceramic) Materials Incorporating Mg, Zn, and F in a Calcium Phosphate Matrix. The materials are designated herein as Mg/Zn/F—CaP. Mg/Zn/F—CaP will consist of one phase (Mg-, Zn- and/or F-substituted carbonate apatite) or of biphasic calcium phosphate, BCP, an intimate mixture of β-TCP (Mg- and Zn-substituted) and carbonate apatite (Mg-, Zn- and F-substituted). (Mg, Zn, F and Ca have been separately associated with bone formation, bone resorption, biomineralization).
[0064] Studies on synthetic and biologic apatites (mineral phases of enamel, dentin and bone) using a combination of analytical techniques (x-ray diffraction, infrared spectroscopy, chemical analysis) demonstrated that biologic apatites (the mineral phases of enamel, dentin, cementum and bone) are not pure hydroxyapatite, Ca 10 (PO 4 ) 6 (OH) 2 (stoichiometric Ca/P molar ratio, 1.67) but are associated with minor constituents (most important of which are magnesium and carbonate) and trace elements. Therefore, biologic apatite such as bone apatite, may be more accurately described as carbonate apatite, approximated by the formula: (Ca,Mg,Na) 10 (PO 4 ,CO 3 ,HPO 4 ) 6 (OH,Cl,F) 2 where Mg, Na and CO 3 are minor constituents and Cl and F may be present in trace amounts. Substitutions or incorporation of different ions in the apatite lattice cause changes in properties: lattice parameters, crystallinity (reflecting crystal size or perfection), and solubility. For example, partial CO 3 -for-PO 4 substitution (coupled with Na-for-Ca substitution) or partial Mg-for-Ca substitution causes an increase in solubility and decrease in crystallinity. Mg and CO 3 have synergistic effects on the properties of apatite. F-for-OH substitution causes a decrease in solubility and increase in crystallinity of synthetic and biologic apatite and promotes formation of less Ca-deficient synthetic apatites. Pure .β-TCP cannot be obtained from solution. However, when Mg or Zn ions are present, Mg- or Zn-substituted β-TCP are formed. The formation of partially substituted Mg or Zn in apatite or in β-TCP or Mg- or Zn-containing amorphous calcium phosphate (ACP) depends on the solution Mg/Ca or Zn/Ca or (Mg+Zn)/Ca molar ratios.
[0065] Mg- and Zn-deficiencies have been implicated as risk factors in the development of osteoporosis. Separately, Mg, Zn or F has been recommended for osteoporosis therapy. Also, separately, these ions have also been shown to promote bone formation and increase bone mass. In rats, at the biologic apatite crystal level, Mg supplementation was shown to cause the formation of smaller bone apatite crystals and smaller enamel apatite crystals while F-incorporation in bone from the drinking water caused the formation of larger and less soluble bone apatite crystals. F has been shown to consistently increase bone mass. However, other studies have reported increased bone fracture with prolonged use of F compounds. F was shown to affect the orientation of collagen and decrease the level of collagen synthesis, modify bone matrix components and was associated with abnormal mineralization. On the other hand, Zn ions were shown to increase collagen and DNA synthesis.
[0066] The material of the present invention, by combining relatively optimum concentrations of F, Mg and Zn ions in a calcium phosphate matrix, combines the beneficial effects of F of these ions on the bone mineral (increasing crystallinity and decreasing solubility) and of Mg and Zn on the organic matrix components thus minimizing deleterious effects of Mg and/or Zn on the bone mineral or deleterious effect of F on bone matrix components. In addition, since these ions appear to act additively or synergistically, the dose for each ion can be reduced to a level that will not be harmful after prolonged use.
Example 3
[0067] Preparation and Characterization of Uncalcined or Unsintered Material Incorporating Mg+F (M/F—CaP), Zn+F (Zn/F—CaP), and Mg+Zn+F (Mg/Zn/F—CaP) in a Calcium Phosphate Matrix.
[0068] Materials and Methods. All chemicals used in the preparation of MZF-CaPs or SBM were reagent grade (Fischer Chemicals, New Jersey). MZF-CaP or SBM were prepared by hydrolysis method. Preparations incorporating only Mg, (MgCaP) or Zn (ZnCaP), F (FCaP) and all three ions (MZFCaP) in a calcium phosphate matrix were made. The preparations were characterized using Xray diffraction (X'Pert, Philips), FTIR (Nicolet 500), thermogravimetry, TGA (, and inductive coupled plasma, ICP (ThermalJarrel Ash) for Ca, Mg, Zn, P, Na contents; and F for F ion selective electrode.
[0069] The MZFCaP or SBM preparations showed XRD profiles shown in FIGS. 1 and 8 . F—CaP, MgCaP and CaP incorporating all three ions, MZFCaP showed only the apatite XRD profiles, with FCAP showing the higher crystallinity (larger crystalsize); while Zn—CaP showed two phases: Zn-substituted tricalciumphosphate (Zn-CP) and apatite. The composition of these preparations is listed in Table 1.
[0070] Ca and P ion concentrations were not significantly different in bones of rats in all diets. However, Zn ion concentration was highest in bone from rats given mineral deficient (md)+Zn—CaP; F ion concentration highest in bones given F—CaP and MZF-CaP; Mg ion concentration was lowest in bones of rats on md diet and not significantly different in bones of rats on normal or supplemented diets. (Table 2). The crystallinity (reflecting crystal size) of bones from rats on basic or supplemented diets were significantly higher (larger crystal size) than those from rats on mineral deficient diets.
Example 4
[0071] The release of ions (Ca, Mg, Zn and P) in acidic buffer (0.1M Kac, pH 6, 37 C) with time, depends on the composition of MZF-CaP. With similar CO 3 concentrations, the higher the F concentration, the lower the rate of release, the higher the Mg and Zn concentrations, the higher the rate of release ( FIGS. 3 and 4 ). Compared to OTC (over the counter) calcium supplements (e.g., CALTRATE® or calcium carbonate) that only released Ca ions in larger amounts at a shorter time, MZF-CaP simultaneously released Ca, P, Mg, Zn and F ions.
[0072] High temperature (800° C. to 1100° C.) preparations. The conditions for high temperature preparation of F-containing carbonate apatites (CFA), Mg-substituted β-TCP (Mg-TCP) and Zn-substituted β-TCP (Zn-TCP) were optimized. Determination of some of the chemical properties (composition, dissolution properties) showed the following: (a) CFA prepared at high temperatures (800° C.) containing high F and low CO 3 contents had lower dissolution rate than that with low F and high CO 3 ( FIG. 9A ) confirming results obtained with CFA's prepared at low temperatures (95° C.); (b) increasing amounts of Mg or Zn in the β-TCP decreased their dissolution rates (FIGS. 9 B, 9 C) similar to that observed with Mg-TCP prepared at low temperature.
Example 5
[0073] Determination of in vitro cell response to MZF-CaPs.
[0074] Osteoblast-like cell response. More than forty MZF-CaP formulations were screened for their effect on the (i) proliferative capacity, (ii) type I collagen production and (iii) phenotype expression of bone markers of osteoblast-like cells (MG-63). Response of osteoblast-like cells on all the MZF-CaPs tested showed increased proliferation, higher production of type I collagen and phenotypic expression of bone markers, including alkaline phosphatase, extracellular matrx (ECM) constituents such as alkaline phosphatase, type I collagen, osteocalcin and proteoglycans.
[0075] Inhibitory effect of Zn-TCP on osteoclastic activity. 10-day-old Japanese white rabbits were used in this study. Cell response to β-TCP with increasing amounts of Zn was determined from formation of an actin ring and expression of the following genes analyzed by quantitative RT-PCR: carbonic anhydrase II (CAII), cathepsin K/OC2, TRAP and glyceraldehydes-3-phosphate dehydrogenase (GAPDH). The resorbing activity of osteoclasts was assessed by measuring the morphological parameters of resorption pits. Results showed that Zn-TCP compared to β-TCP, suppressed the activity of mature osteoclasts through reduction in actin ring formation ( FIG. 10A ), down-regulation of CAII and cathepsin K expressions ( FIG. 10B ) without significant change in the expression of TRAP and increased cell apoptosis ( FIG. 10C ), in a dose dependent manner.
Example 6
[0076] Determine the effect of orally administered various Mg/Zn/F—CaPs on bone properties of mineral deficient rats.
[0077] Sprague-Dawley rats (Charles River Labs), 2 months old (average weight, 165 g) were randomly distributed into the following groups (10 per group for female or male rats): GA: on basic diet; GB: on mineral deficient diet (MD); GC: on MD diet+Mg—CaP; GD: MD diet+Zn—CaP; GE: MD diet+F—CaP; and GF: on MD+Mg/Zn/F—CaP (MZF-CaP) for 3 months. Rat food pellets (basic, mineral deficient and supplemented mineral deficient diets) were prepared by Purina Test Diets. Compositions of the MZF-CaP preparations and of the diets are summarized in Tables I and 3, respectively. Animal protocol was approved by NYU IUCAC and adhered to the NIH guidelines for the care and use of laboratory animals. The rats were sacrificed by CO 2 inhalation. The bones (femurs, tibias, vertebras, jawbones) were separated, cleaned of soft tissues and stored according to type of analyses: femurs for bone strength analyses were wrapped in wet gauze and directly frozen; other bones were stored in 70% alcohol and stored at °20° C. Bones for x-ray diffraction (X'Pert Philips), SEM (Hitachi S3500N), radiography (Faxitron Series 43805 N X-ray System, Hewlett-Packard), and microcomputed tomography, microCT (μCT 40, Scanco Medical, Switzerland). Tibias for compositional analysis (by inductive coupled plasma for Ca, Mg, Zn, and P and by F-ion selective electrode for F) were ashed at 600° C. Other tibias were enzyme treated and analyzed as unashed samples. Composition of unashed cortical bone is summarized in Table 2. Bone strength ( FIG. 11 ) was determined by 3-point bending using universal testing machine (Instron). SEM images showed that mineral-deficient (MD) diet caused thinning of the cortical bone ( FIG. 12B ), and MD diet supplemented with Mg—CaP ( FIG. 12C ), Zn—CaP ( FIG. 12D ), F—CaP and especially ( FIG. 12E ), MZF-CaP ( FIG. 12F ), prevented bone loss. Similar effects on trabecular bone thickness ( FIG. 13 ), bone density and trabecular bone connectivity were observed.
[0000]
TABLE 3
Composition of the diets given to the rats.
Diet
wt % Ca
wt % P
wt % Mg
ppmZn
ppmF
Basic
0.6
0.57
0.07
21
0.0
Mineral deficient(MD)
0.0
0.0
0.17
0.0
0.0
MD + Mg—CaP(#53)
0.17
0.29
0.07
1.0
0.0
MD + Zn—CaP
0.17
0.21
0.0
370
0.0
MD + F—CaP
0.19
0.27
0.0
0.0
67.2
MD + MZF—CaP
0.18
0.27
0.02
276
66.3
Example 7
[0078] Prevention of bone loss induced by ovariectomy. Non-OVX and OVX Sprague-Dawley rats (3 months old, average weight, 225 g) were distributed into the following groups: G1: control (non-Ovx Rats); G2: OVX rats on basic diet (BD); G3: OVX rats on BD supplemented with MZF-CaP for 5 months. After sacrifice, femurs, tibia, vertebra, and jawbones were collected, cleaned of extraneous tissues and stored according to what type of analyses will be performed. Mechanical test (3-point bending) were determined using femurs. TGA, XRD and FT-IR analyses were made on tibia and vertebra, SEM and microCT on femurs that were cleaned of extraneous soft tissues; Ca, P, Mg, Zn, Na and F determinations were made on ashed (800° C.) bones. Faxitron, (radiography), SEM and microCT images showed that bone loss induced by estrogen deficiency was prevented when diet was supplemented with MZF-CaP. Results from these studies demonstrated that MZF-CaPs administered daily as supplement to mineral deficient or basic diets were effective in preventing bone loss enhancing bone strength induced by mineral deficiency or estrogen deficiency (ovariectomy) in rats.
Example 8
Determine Therapeutic Effect of MZF-CaP Administered by Weekly Injection on Ovariectomized Rats on Enhancing Bone Properties (Bone Density and Bone Strength)
[0079] Sprague Dawley rats (4 weeks old) were used. The rats were randomly assigned to 6 groups (6 rats per group): GN—normal (non-OVX); GC: control (OVX rats on Zn-deficient diet); G1, G2, G3 and G4 were OVX. Rats receiving weekly injections of Zn-TCP (G1), MZF-CaP #51 (G2), MZF-CaP#68 (G3) and MZF-CaP#76 (G4). The compositions of these MZF-CaPs are listed in Table 1. The composition of Zn-TCP: 6.17 wt % Zn; 34.1 wt % Ca and 19.5 wt % P. 10 mg of MZF-CaP or Zn-TCP in 0.1 mL saline solution was injected intramuscularly in the right thighs of the OVX rats in all groups once a week for 12 weeks and 16 weeks. Results showed that the bone mineral densities (BMD) of the treated groups (G1 to G4) were greater than the OVX groups (GC) ( FIG. 14 ).
Example 9
Determine the Effect of MZF-CaP Supplement in Preventing Bone Loss Induced by Estrogen Deficiency (Ovariectomy)
[0080] Non-OVX and OVX Sprague-Dawley rats (3 months old, average weight, 225 g) were randomly distributed in the following groups (4 rats per group): G1: control (non-Ovx rats) on basic diet (BD), 5 months; G2: non-OVX rats on BD+MZF-CaP (#74); G3: OVX rats on BD for 3 months, then BD+#74 for 2 months; G4: OVX rats on BD supplemented with MZF-CaP, 5 months. Improved bone strength ( FIG. 15 ), improved microarchitecture ( FIGS. 16B vs 16 A; 17 B vs 17 A), and decreased susceptibility to acid dissolution in acidic buffer ( FIG. 18 ) were observed in bones from rats with basic diets supplemented with MZF-CaP. In a continuing study, the effect of MZF-CaP (with low fluoride) and of MZ-CaP/FF on preventing bone loss induced by ovariectomy will be evaluated using larger number of rats and correlating bone strength with bone quality.
[0081] FIGS. 19 and 20 represent the effect of Mg/Zn/F—CaP dietary supplements on recovery of bone loss induced by estrogen deficiency (ovariectomy) in rats. FIG. 19 represents microCT images of the femoral heads from (A) non-ovariectomized rats on a basic diet, (B) ovariectomized rats on a basic diet after two months, and (C) ovariectomized rats on a basic diet supplemented with Mg/Zn/F—CaP supplements after one month. FIG. 20 provides microCT images of femur head that demonstrate further the recovery in bone loss that may be achieved by providing a Mg/Zn/F—CaP dietary supplement. (A) is a microCT demonstrating the femur head of a rat on a basic diet, (B) is a microCT demonstrating bone loss in the femur head of a rat fed a mineral-deficient diet for two months, and (C) is a microCT demonstrating recovery of bone in the femur head of a rat fed a mineral-deficient diet for two months followed by a diet having a Mg/Zn/F—CaP dietary supplement for one month.
[0082] While the present invention has been described in terms of specific embodiments thereof, it will be understood in view of the present disclosure, that numerous variations upon the invention are now enabled to those skilled in the art. Accordingly, the invention is limited only by the scope and spirit of the claims appended. | The present invention provides novel biomaterials comprising one or more of Mg, Zn and F ions in a carbonate-containing biphasic calcium phosphate (BCP) system. The biomaterial may contain Mg, Zn, F, Mg and Zn, Mg and F, Zn and F, or Mg, Zn and F. The biomaterial may be substantially similar in composition to bone mineral (a carbonate apatite). The biomaterial may feature slow release of Mg, Zn, F, Ca, and P ions. The biphasic calcium phosphate, BCP, may be a mixture of unsubstituted hydroxyapatite (HA) and unsubstituted .-TCP, Ca 3 (PO 4 ) 2 . BCP of varying HA/.-TCP ratios may be produced by sintering calcium-deficient apatite, for instance having a Ca/P<1.5, 1.6, 1.67, 1.75 or 1.8 that has been prepared either by a precipitation or by a hydrolysis method or by a solid-state reaction. The amount of each component (by weight %) present in the biomaterials may be as follows: Mg 0.5 to 12 wt %, Zn 1 to 12 wt %, F 0.1 to 4 wt %, calcium 20 to 40 wt %, phosphate 10 to 20 wt %, and carbonate (CO 3 ) 1 to 20 wt %. The biomaterial may further comprise one or more other ion such as strontium, manganese, copper, boron or silicate, or one or more other organic moiety such as a protein, a peptide, or a nutraceutical which may provide antioxidant, anti-bacterial or anti-inflammatory properties. The invention also provides methods of inhibiting bone resorption, methods of treating osteoporosis or delaying the onset of osteoporosis, methods of treating a bone fracture, and methods of inhibiting osteoclast activity. Further, the invention provides methods of treating or reversing bone deficiencies such as bone loss, similar to osteoporosis, caused all or in part by a mineral deficient diet, a disease such as cancer or osteopenia, a treatment such as steroid therapy or radiation therapy, or a physical condition such as immobilization. | 0 |
CROSS-REFERENCES TO RELATED APPLICATIONS
The priority of Korean patent application number 10-2007-0128346, filed on Dec. 11, 2007, which is incorporated by reference in its entirety, is claimed.
BACKGROUND OF THE INVENTION
The present invention relates to a semiconductor device, and more specifically to a method of increasing the level of integration while maintaining the reliability of a device by using a stacked structure.
A semiconductor device comprises of a plurality of circuits. Generally, a memory semiconductor device like DRAM is comprised of a cell region, a core region, and a peripheral region. The cell region stores data. The core region has a circuit for accessing data stored in the cell region. The peripheral region has a circuit for driving the memory semiconductor device and the data input/output.
In the cell region, memory cells including a cell transistor and a cell capacitor are arranged in an array type. Such a cell region includes a plurality of unit cell arrays.
In the core region, the circuit including a sub-word line driver and a sense amplifier is formed. At this time, the sub-word line driver drives the sub-word line according to the voltage level of the main word line. The sense amplifier senses and amplifies the data of a cell.
A bank includes a plurality of unit cell arrays and a plurality of core regions. For example, in the case of the DDR2 512 Mbit device, it has four banks. The peripheral region in which the circuit including a free decoder, an input buffer, and an output buffer is formed is provided between these banks.
Recently, more circuits, particularly, more memory cells have to be formed in a limited chip area, since high integration is required as the size of the semiconductor device has been reduced.
However, a trade-off relation exists between the net die increment and the reliability assurance of a device. Thus, the reliability of a device is decreased if the net die is increased. That is, in the current DRAM structure, there is a structural limit in increasing the net die while not reducing the reliability of a device.
BRIEF SUMMARY OF THE INVENTION
Embodiments of the present invention relate to maintaining the reliability of a semiconductor device and improve the integration through increasing a cell region by forming the cell region and a core region with a stacked structure.
According to an embodiment of the present invention, a semiconductor device includes a cell array region formed on a first semiconductor substrate; and a core circuit unit formed on a second semiconductor substrate over the cell array.
The core circuit unit comprises at least one of a sense amplifier and a sub-word line driver. The sense amplifier is electrically connected to a bit line of the cell array. The sub-word line driver is electrically connected to a word line of the cell array. The second semiconductor substrate is an epitaxial growth layer with the first semiconductor substrate as a seed layer. The semiconductor device according to an embodiment of the present invention further comprises a contact region for forming the second semiconductor substrate by growing the first semiconductor substrate. The semiconductor device according to an embodiment of the present invention further comprises an insulating layer formed between the cell array region and the second semiconductor substrate. The insulating layer has a thickness range from 500 Å to 5,000 Å. The insulating layer is formed with one of an oxide film, a nitride film and the combinations thereof.
According to an embodiment of the present invention, a method of fabricating a semiconductor device includes forming a cell array on a first semiconductor substrate; forming a second semiconductor substrate over the cell array; and forming a core circuit on the second semiconductor substrate.
The forming a second semiconductor substrate comprises forming a contact hole which exposes the first semiconductor substrate by selectively etching a interlayer dielectric layer included in the cell array; and growing the first semiconductor substrate through the contact hole. The method of fabricating a semiconductor device according to an embodiment of the present invention further comprises planarly etching the grown up semiconductor substrate. The growing the first semiconductor substrate performs an epitaxial growth method with the first semiconductor substrate exposed through the contact hole as a seed layer. The method of fabricating a semiconductor device according to an embodiment of the present invention further comprises forming an insulating layer between the cell array and the second semiconductor substrate. The insulating layer has a thickness range from 500 Å to 5,000 Å. The insulating layer is formed with one of an oxide film, a nitride film and the combinations thereof. The forming a core circuit comprises forming a device isolation structure defining an active region in the second semiconductor substrate; and forming a transistor on the active region. The method of fabricating a semiconductor device according to an embodiment of the present invention further comprises electrically connecting a sense amplifier of the core circuit and a bit line of the cell array. The method of fabricating a semiconductor device according to an embodiment of the present invention further comprises electrically connecting a sub-word line driver of the core circuit and a word line of the cell array.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a layout of a semiconductor device according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view taken along I-I′ of the semiconductor device of FIG. 1 .
FIGS. 3 a to 3 d are cross-sectional views showing the manufacturing method of the semiconductor device of FIG. 2 .
DESCRIPTION OF EMBODIMENTS
FIG. 1 is a layout of a semiconductor device according to an embodiment of the present invention, showing banks of the semiconductor device.
The semiconductor device includes a first semiconductor substrate region 102 , a second semiconductor substrate region 104 and a cell/core region 108 .
The unit cell array including word lines (not shown), bit lines (not shown), and memory cells are formed on the first semiconductor substrate region 102 . Each memory cell includes a cell transistor and a cell capacitor.
The second semiconductor substrate region 104 is used as a core circuit region where circuits such as sense amplifier and a sub-word line driver are formed. The second semiconductor substrate region 104 includes a contact region 106 , and formed over the first semiconductor substrate region 102 . That is, in the present embodiment, the first semiconductor substrate region 102 and the second semiconductor substrate region 104 are formed in a stacked structure.
Since the first semiconductor substrate region 102 and the second semiconductor substrate region 104 are formed on different layers, the size of the first semiconductor substrate region 102 can be increased. Therefore, the cell efficiency and the process margin can be improved as the cell array region is increased. In one embodiment, the contact region 106 is formed at outer side of the first semiconductor substrate region 102 , but may be formed at other locations.
The cell/core region 108 is a region including the first semiconductor substrate region 102 and the second semiconductor substrate region 104 .
FIG. 2 is a cross-sectional view taken along I-I′ of the semiconductor device of FIG. 1 .
The semiconductor device includes a cell array unit 260 and a core circuit unit 290 . At this time, the cell array unit 260 and the core circuit unit 290 are formed in a stacked structure. For example, the core circuit unit 290 is formed over the cell array unit 260 .
The cell array unit 260 includes memory cells having a gate 230 and a capacitor 250 . The memory cells are arranged in an array. In the present embodiment, for the sake of convenience, only two memory cells are shown.
The cell array unit 260 includes the gate 230 , a bit line 240 and the capacitor 250 . The gate 230 is formed in a first active region 210 a of a first semiconductor substrate (or first semiconductor material) 210 defined by a first device isolation structure 220 . And the bit line 240 is formed in a second interlayer dielectric layer 243 while being electrically connected to a landing plug 233 b formed between the gates 230 . The capacitor 250 is formed on a storage electrode contact plug 247 and a third interlayer dielectric layer 245 . The storage electrode contact plug 247 is electrically connected to a landing plug 233 s , and is formed within the second interlayer dielectric layer 243 and the third interlayer dielectric layer 245 . In addition, the third interlayer dielectric layer 245 is formed on the bit line 240 and the second interlayer dielectric layer 243 .
The core circuit unit 290 includes a second semiconductor substrate (or second semiconductor material) 270 , a second device isolation structure 273 , and a transistor 280 . The second semiconductor substrate 270 is formed over the cell array unit 260 . At this time, the second semiconductor substrate 270 may be formed with an epitaxial growth layer which uses the first semiconductor substrate 210 as a seed layer. For example, a first to a fourth interlayer dielectric layer 235 , 243 , 245 , 249 are selectively etched until the first semiconductor substrate 210 is exposed so that the contact hole 253 is formed. Then, the epitaxial growth is carried out with the first semiconductor substrate 210 exposed in the lower portion of the contact hole 253 as a seed layer so that the second semiconductor substrate 270 can be formed. In other embodiments, the second semiconductor substrate (or layer) may be formed using different methods according to application.
The transistor 280 is formed on a second active region 270 a defined with the second device isolation structure 273 . The transistor 280 may be an element used to form the core circuit such as a sense amplifier or a sub-word line driver. The transistor 280 may be electrically connected to the word line (not shown) or the bit line 240 of the cell array unit 260 . An insulating layer 263 is formed between the second semiconductor substrate 270 and the capacitor 250 in order to isolate the cell array unit 260 and the core circuit unit 290 . The insulating layer 263 may be formed with one of the oxide film, the nitride film and combinations thereof.
FIGS. 3 a to 3 d are cross-sectional views showing the manufacturing method of the semiconductor device of FIG. 2 .
A first device isolation structure 320 is formed on a first semiconductor substrate 310 including a cell array region 3000 c and a contact region 3000 p to define a first active region 310 a . A gate 330 is formed on the first active region 310 a . In the present embodiment, the gate 330 has the recess structure, but it is not limitative.
A first interlayer dielectric layer 335 is formed on the first device isolation structure 320 , the first active region 310 a , and the gate 330 . Then, a landing plug contact hole (not shown) exposing the first active region 310 a is formed between the gates 330 by eliminating a part of a first interlayer dielectric layer 335 . And a first conductive layer (not shown) is formed so that the landing plug contact hole can be filled. Landing plugs 333 s , 333 b are isolated by using a planarizing etch for the first conductive layer until the upper portion of the gate 330 is exposed.
A second interlayer dielectric layer 343 is formed on the landing plugs 333 s , 333 b , the gate 330 , and the first interlayer dielectric layer 335 . Then, a part of a second interlayer dielectric layer 343 is selectively etched in order to expose the landing plug 333 b so that a bit line contact hole (not shown) is formed. After a second conductive layer (not shown) is formed on the second interlayer dielectric layer 343 including the bit line contact hole, a bit line 340 is formed by patterning the second conductive layer with a bit line mask (not shown).
A third interlayer dielectric layer 345 is formed on the bit line 340 and the second interlayer dielectric layer 343 . A storage electrode plug contact hole (not shown) which exposes the landing plug 333 s is formed by selectively etching a part of the third interlayer dielectric layer 345 and the second interlayer dielectric layer 343 . After a third conductive layer (not shown) is formed on the third interlayer dielectric layer 345 including the storage electrode plug contact hole, a storage electrode contact plug 347 is formed by planarly etching the third conductive layer.
Then, after a fourth interlayer dielectric layer 349 is formed on the storage electrode contact plug 347 , the fourth interlayer dielectric layer 349 is selectively etched to form a storage electrode contact hole (not shown) exposing the storage electrode contact plug 347 . After a fourth conductive layer (not shown) is formed on the fourth interlayer dielectric layer 349 including the storage electrode contact hole, a bottom plate 355 is formed by planarly etching the fourth conductive layer.
Then, after the dip-out process is performed to eliminate the fourth interlayer dielectric layer 349 of the cell array region 3000 c , a dielectric layer (not shown) and an top plate 357 are formed on the first semiconductor substrate 310 including the bottom plate 355 . At this time, the capacitor 350 includes the bottom plate 355 , the dielectric layer, and the top plate 357 . As a result, a cell array 360 is formed in the cell array region 3000 c . As to the method for forming the cell array on the semiconductor substrate 310 , other methods apart from the above-described method can be applied.
Thereafter, an insulating layer 363 is formed over the first semiconductor substrate 310 including the unit cell array region 3000 c and the contact region 3000 p . The insulating layer 363 electrically isolates the core circuit to be formed from the cell array 360 . In addition, the insulating layer 363 may be formed to a thickness of 500 Å to 5,000 Å. The insulating layer 363 may be formed with one of an oxide film, a nitride film and combinations thereof. Other dielectric materials may be used in other implementations.
Referring to FIG. 3 b , after a photosensitive layer (not shown) is formed on the insulating layer 363 , the photosensitive pattern 365 is formed through an exposure and development process for the photosensitive layer by using the mask (not shown), exposing a part of the contact region 3000 p . Then, a contact hole 353 which exposes the first semiconductor substrate 310 is formed by selectively etching the insulating layer 363 and an interlayer dielectric layer 367 using the photosensitive pattern 365 as a mask.
Referring to FIG. 3 c , the photosensitive pattern 365 is removed. A second semiconductor substrate 370 is epitaxially grown on the insulating layer 363 using a portion of the first semiconductor substrate 310 exposed by the contact hole 353 as a seed layer. The second semiconductor substrate 370 fills the contact hole 353 due to the epitaxial growth method. In one embodiment, the epitaxial growth method is performed in a temperature range of 350° C. to 850° C. The epitaxial growth method fills the contact hole 353 . And the growth time can be controlled so that the second semiconductor substrate 370 is formed over unit cell array region 3000 c and the contact region 3000 p.
Then, the second semiconductor substrate 370 is planarized. The planarization process can be performed using the chemical mechanical polishing (CMP), the etch-back method, or both. Although the second semiconductor substrate 370 is formed over both the cell array region 3000 c and the contact region 3000 p , the invention is not limited to such an embodiment. For example, the second semiconductor substrate 370 can be formed on a part of the cell array region 3000 c or the contact region 3000 p.
Referring to FIG. 3 d , a second device isolation structure 373 defining a second active region 370 a is formed in the second semiconductor substrate 370 . A transistor 380 is formed on the second active region 370 a . The second semiconductor substrate 370 and the transistor 380 form a core circuit 390 such as a sense amplifier and a sub-word line driver. In addition to the sense amplifier and the sub-word line driver, the core circuit 390 may have other types of circuits.
Thereafter, in the subsequent interconnection forming process, an interconnection (not shown) which electrically connect the word line (not shown) of the cell array 360 , or the bit line 340 to the core circuit 390 is formed. For example, the interconnection is formed in order that the sense amplifier of the core circuit 390 is connected to the bit line 340 , while the interconnection is formed in order for the sub-word line driver of the core circuit 390 to be connected to the word line. After that, the subsequent processes such as a fuse formation process is performed and the semiconductor device can be completed.
As described above, by forming the first semiconductor substrate in which the cell array is formed and the second semiconductor substrate in which the core circuit is formed with the stacked structure, the present invention can increase the cell array region while securing the reliability and the process margin of a device.
It will be apparent to those skilled in the art that various modifications and variation can be made in the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. | The present invention relates to a semiconductor device and a method of manufacture thereof, being capable of improving the high integration by increasing a cell region while securing the reliability of device and the process margin through forming a cell region and a core region with the stacking structure. | 7 |
FIELD OF INVENTION
[0001] The present invention relates to a new Lamivudine polymorphic form, pharmaceutical formulations thereof.
BACKGROUND OF THE INVENTION
[0002] Lamivudine (I) (CAS No. 134678-17-4) is chemically known as (2R-cis)-4-amino-1-[2-(hydroxymethyl)-1,3-oxathiolan-5-yl]-2(1H)-pyrimidinone, also known as (−) cis-4-amino-1-(2-hydroxymethyl-1,3-oxathiolan-5-yl)-(1H)-pyrimidin-2-one
[0000]
[0003] Lamivudine is a reverse transcriptase inhibitor used in the treatment of HIV infection alone or in combination with other class of Anti HIV drugs.
[0004] Lamivudine is commercially available in a pharmaceutical composition under the brand name EPIVIR® marketed by GlaxoSmithKine and is covered under U.S. Pat. No. 5,047,407.
[0005] U.S. Pat. No. 5,047,407 claims 1,3-oxathiolane derivatives, their geometric and optical isomers and mixtures thereof. The patent also discloses the preparation of cis and trans isomers of 2,5 substituted 1,3-oxathiolane derivatives.
[0006] U.S. Pat. No. 5,905,082 describes two polymorphic modifications of Lamivudine viz form I and II. Form 1 crystals are short rods or long thin needles with orthorhombic crystal system. Form 1 is a hydrate of Lamivudine consisting of one molecule of water per five molecules of Lamivudine. This form melts at 146° C. (Journal of Chem. Soc., Perkin Trans. 2, page 2655 (1997)). The DSC thermogram (the rate of heating: 2° C./min) of this form shows first an endotherm at 123.6° C. followed by an exotherm at 128° C., finally another endotherm at 179.6° C. This second endotherm is due to conversion of crystal form I to form II, hence form 1 is a metastable crystalline form.
[0007] However with rate of heating of 100° C./min form I shows a single endotherm at 146° C., which is it's melting point. The TGA shows a single step sharp weight loss of 2%.
[0008] Form I as per U.S. Pat. No. 5,905,082 is prepared by heating a suspension of 64.8 gm Lamivudine in 200 ml water at 45° C. to give a solution and cooling the solution to 30° C. The product crystallizes out as an unstirrable mass. Further breaking this mass and cooling it to 10° C. with stirring and thereafter filtering and drying at 45° C. for 24 hours gives form I crystals.
[0009] Form II crystals as disclosed in U.S. Pat. No. 5,905,082 are bipyramidal in shape with tetragonal crystal system. It is an anhydrous form of Lamivudine. This form melts at 177° C. (Journal of Chem. Soc., Perkin Trans. 2, page 2655 (1997)). The DSC thermogram of this form at all scan speeds shows a single peak of endotherm at 177° C. Form II is a stable crystalline form of Lamivudine and is claimed in U.S. Pat. No. 5,905,082.
[0010] Form II as per U.S. Pat. No. 5,905,082 is prepared by following procedure: Heat a suspension of 10 gm Lamivudine in 200 ml of industrial methylated spirit to reflux to obtain a clear solution. Filter the solution while hot; distil half the amount of the solvent from the filtrate then stop heating and seed the concentrated solution with authentic form II crystals. The seeded solution is then cooled from 80° C. to 25° C. during one hour. Crystal formation starts at 79° C. Further cooling the suspension to 15° C. and stirring for an hour, filtration, washing with IMS and drying gives Form II crystals.
[0011] Crystalline form I have inferior flow property and also lower bulk density, which create problem in handling the product during formulation. In view of the literature cited hereinbefore Lamivudine form I also suffers from stability issues. Therefore, it is desirable to develop a crystalline form of Lamivudine having improved stability and also comparable if not better bioavailability.
[0012] When slurried in water both crystal form I and II get converted to another polymorphic form not yet reported in the literature, which is really not a desirable feature for manufacturing practices. Form I converts to form II during milling and formulation operation and because of this the invention embodied in U.S. Pat. No. 5,905,082 for getting form II, a thermodynamically stable polymorph, used for formulation.
[0013] The present inventors have surprisingly i found that Lamivudine can also be obtained in a third crystalline form (hereinafter form III), which not only have distinct powder X-ray diffractogram but also have entirely different single crystal X-ray diffraction when compared to form I and II.
OBJECTS OF THE INVENTION
[0014] Thus an object of the present invention is to provide a novel crystalline hemihydrate form of Lamivudine with better flow property and bulk density, which enables to have a formulation without any difficulty.
[0015] Another object of the present invention is to provide a novel crystalline hemihydrate form of Lamivudine with comparable dissolution rate with the reported polymorphic forms of lamivudine.
[0016] Yet another object of the present invention is to provide a novel crystalline form of Lamivudine that is stable during wet granulation using water as a granulating solvent, thereby ensuring the physical stability of the finished solid dosage form.
[0017] A further object of the present invention is to provide a process for preparation of novel crystalline hemihydrate of Lamivudine using eco-friendly solvent “water”.
[0018] Another object of the present invention is to provide suitable pharmaceutical dosage forms of novel crystalline hemihydrate of Lamivudine alone or in combination with other anti HIV agents.
SUMMARY OF INVENTION
[0019] Thus in the present invention there is provided a crystalline hemihydrate (form III) of Lamivudine having characteristic powder and single crystal X-ray diffraction as shown in FIGS. 1 and 16 with characteristic 2θ values as given in Table III.
[0020] According to another aspect of the present invention there is provided a method for formation of Form III by dissolving Lamivudine in water at 45° C., then cooling the clear solution to 30° C., optionally seeding with form III crystals and further cooling to 10° C. at the rate ranging from 0.5° C./min to 3.5° C./min, isolating the crystals by filtration optionally washing with alcohol and drying at 45-55° C.
DESCRIPTION OF THE INVENTION
[0021] As mentioned earlier both form I and form II polymorphs when slurried in water get converted to polymorphic form III, which happens to be thermodynamically stable and does not undergo any change in crystal structure during milling.
[0022] This crystal form has been found to have better flow property and higher bulk density in comparison with literature reported forms.
[0023] Further study on single crystal X-ray diffraction reveals that it is a hemihydrate form (four molecules of Lamivudine with two molecules of water) of Lamivudine. This product melts at 176-177° C. The DSC thermogram (at the rate of heating=2° C./min) shows first peak of endotherm (Δ H=16.61 J/g) at 100° C. and the second peak of endotherm (Δ H=101.68 J/g) at 179.60. This crystal form is found to be stable and has better flow property than form 1, and is found to posses comparable bioavailability.
[0024] The crystal form III of Lamivudine is obtained by subjecting the hot (45° C.) supersaturated solution of Lamivudine for controlled cooling. Whereas if such solution is cooled suddenly it gives form 1 crystals of Lamivudine.
[0025] Thermogravimetric analysis (as shown in FIG. 6 ) of form III crystals of Lamivudine shows 3.5 to 4% single step loss of weight. Moisture content of this crystal form by Karl Fischer titration is in the range of 3.5 to 4.0%, which confirms presence of approximately one mole of water per every two moles of Lamivudine.
[0026] Single crystal structure X-ray data ( FIG. 16 ) reveals two molecules of water are associated with four molecules of lamivudine presumably through hydrogen bonds in polymorphic form III. In other words the material of present invention is a hemihydrate having four molecules of lamivudine and two molecules of water. Form III thus obtained has a melting point of 176 to 177° C.
[0027] The novel crystalline hemihydrate form (form III) of Lamivudine has better flow property and bulk density, which are important parameters for formulation (Table I).
[0000]
TABLE I
Property
Form I
Form II
Form III
Bulk Density (gm/cc)
0.46
0.38
0.64
Tap Density (gm/cc)
0.60
0.55
0.83
Flow Property
33.66°
32.00°
32.00°
(Angle of Repose $ )
$ measured as per the procedure provided on page 317 of ‘The Theory and Practice of Industrial Pharmacy’ by Leon Lachman et al., Third Ed. Varghese Publishing House, Bombay; (1987)
[0028] Lamivudine Form I and Form II when slurried in water at ambient temperature for 24 to 48 hours get converted to Form III, which is not at all desirable since during formulation especially in wet granulation such conversion would lead to physical instability of the finished formulation. Hence, use of Lamivudine Form III crystals would certainly have an added advantage over other polymorphic forms mentioned in the literature.
[0029] The crystalline form III of Lamivudine as disclosed herein was found to be stable for more than three months when stored at 40±2° C. RH 75±5%.
[0030] Comparative thermal analysis data is tabulated in Table II
[0000]
TABLE II
Crystal
Form
Melting Point
DSC
TGA
I
135-145° C.
@ 2° C./min: exotherm at 123°
One step weight loss
124-127° C.*
then at 177° (FIG. 7)
between temp 80° C. to
135° C. #
@ 100° C./min: 146° C. (FIG. 8)
140° C. = 1.52%
(FIG. 4)
II
177-178° C.
@ 2° C./min and 100° C./min:
No weight loss due to
177-178° C.* #
177° C. (FIG. 9 & 10)
crystal bound water.
(FIG. 5)
III
176-177° C.
@ 2° C./min first peak at 100° C.
One step weight loss
and second at 177° C. (FIG. 11)
between temp 80° C. to
@ 100° C./min: 120° C. (FIG. 12)
140° C. = 4.14%
(FIG. 6)
[0031] The powder X-ray diffraction analysis of form III also shows characteristic 2θ values. Comparative data of 2θ values form III and other literature reported polymorphic forms is provided in Table III
[0000]
TABLE III
Form I (FIG. 1)
Form II (FIG. 2)
Form III (FIG. 3)
(2θ values)
(2θ values)
(2θ values)
5.20
10.70
5.50
6.66
12.17
7.60
8.53
13.42
9.00
8.81
14.30
9.62
9.65
14.76
10.98
9.85
15.86
11.97
10.15
16.83
12.52
10.41
17.55
12.81
11.27
18.63
13.52
11.38
19.68
15.19
11.63
20.63
15.71
12.34
21.44
15.94
12.60
22.13
16.57
12.93
22.60
16.72
13.22
23.03
17.11
14.60
24.44
17.57
15.01
24.94
17.98
15.17
25.70
18.30
15.67
26.51
19.26
15.81
27.68
19.68
16.51
28.41
20.37
17.59
28.93
21.04
17.98
29.72
22.00
18.13
30.67
22.86
18.72
30.90
23.40
19.10
31.30
23.70
19.30
31.47
24.04
19.76
31.99
24.68
21.788
32.40
25.15
23.487
32.59
26.97
23.706
33.14
27.70
25.44
34.01
28.74
25.90
35.20
30.35
27.34
35.49
30.60
29.46
37.27
31.94
31.00
38.46
33.25
[0032] The single crystal X-ray diffraction data obtained for form III crystalline form of Lamivudine is tabulated in Table IV
[0033] Suitable pharmaceutical formulations may conveniently be presented containing predetermined amount of lamivudine in crystalline form III
DESCRIPTION OF ACCOMPANYING FIGURES
[0034] FIG. 1 : Powder X-ray diffractogram of crystalline form I of Lamivudine.
[0035] FIG. 2 : Powder X-ray diffractogram of crystalline form II of Lamivudine.
[0036] FIG. 3 : Powder X-ray diffractogram of crystalline form III of Lamivudine.
[0037] FIG. 4 : TGA thermogram of crystalline form I of Lamivudine.
[0038] FIG. 5 : TGA thermogram of crystalline form II of Lamivudine.
[0039] FIG. 6 : TGA thermogram of crystalline form III of Lamivudine.
[0040] FIG. 7 : DSC thermogram of crystalline form I of Lamivudine at heating rate 2° C./min.
[0041] FIG. 8 : DSC thermogram of crystalline form I of Lamivudine at heating rate 100° C./min.
[0042] FIG. 9 : DSC thermogram of crystalline form II of Lamivudine at heating rate 2° C./min.
[0043] FIG. 10 : DSC thermogram of crystalline form II of Lamivudine at heating rate 100° C./min.
[0044] FIG. 11 : DSC thermogram of crystalline form III of Lamivudine at heating rate 2° C./min.
[0045] FIG. 12 : DSC thermogram of crystalline form III of Lamivudine at heating rate 100° C./min.
[0046] FIG. 13 : FTIR spectra of crystalline form I of Lamivudine.
[0047] FIG. 14 : FTIR spectra of crystalline form II of Lamivudine.
[0048] FIG. 15 : FTIR spectra of crystalline form III of Lamivudine.
[0049] FIG. 16 : crystal structure and packing diagram of crystalline form III of Lamivudine obtained by Single crystal X-ray diffraction analysis
[0050] The present invention is illustrated in more detail by referring to the following Examples, which are not to be construed as limiting the scope of the invention.
EXAMPLE 1
Preparation of Lamivudine Form III
[0051] A suspension of the Lamivudine form-II (25.0) g in water (75.0 ml) was heated to 45° C. in 20 min to give a clear solution. The solution was cooled to 30° C. during a period of 30 min. The crystallization started at 30° C. The mass was further cooled to 10° C. during a period of 20 min and stirred for 1 hour. The product was filtered and washed with ethanol (2×10 ml) then dried in vacuum at 45° C. for 24 hours. Yield=23.0 gms.
[0052] IR Spectra [Nujol Mull] (cm −1 ): 3330, 3160, 2923, 2854, 1640, 1600, 1522, 1460, 1376, 1296, 1226, 1193, 1155, 1135, 1106, 1044, 976, 927, 844, 788, 722 ( FIG. 15 )
[0053] X-ray powder diffraction analysis shows peaks at about 5.50, 7.60, 9.00, 9.62, 10.98, 11.97, 12.52, 12.81, 13.52, 15.19, 15.71, 15.94, 16.57, 16.72, 17.11, 17.57, 17.98, 18.30, 19.26, 19.68, 20.37, 21.04, 22.00, 22.86, 23.40, 23.70, 24.04, 24.68, 25.15, 26.97, 27.70, 28.74, 30.35, 30.60, 31.94, 33.25±0.2 °2θ.
[0054] The single crystal X-ray analysis is carried out using SMART APEX CCD diffractometer by full-matrix least-squares refinement on F 2 ; goodness of fit on F 2 was 1.050. A total of 20474 reflections were measured on diffractometer with monochromatised Cu—Kα radiation. The data was collected at θ ranging from 1.26 to 25°. The structure was solved by direct method and the non-hydrogen atoms refined anisotropically. All H atoms were refined isotropically. Refinement converged to give R1=0.0538, wR2=0.1428. Minimum residual electron density was −0.403 e. Å −3 and maximum residual electron density was 0.887 Å −3 . The data is as shown below in Table IV:
[0000]
TABLE IV
Empirical Formula
2(C 8 H 11 N 3 O 3 S)•(H 2 O)
Formula weight
476.53
Crystal System
Monoclinic
Space group
P2 1
Unit cell dimensions
a = 11.714 (9) Å
α = 90°
b = 11.214 (9) Å
β = 94.68°
c = 16.197 (12) Å
γ = 90°
Z, calculated density
2, 1.493 Mg/m 3 .
Cell volume
2120.4 (3) Å 3
Crystal size
0.18 × 0.11 × 0.09
[0055] Powder pattern generated from single crystal data using MERCURY software was found to be identical to the experimental powder X-ray diffraction pattern of the material of invention (as provided for Form III in Table III and in FIG. 3 ).
[0056] The differential scanning calorimetric analysis at the rate of heating 2° C./min shows first peak of endotherm at 100° C. and second at 177° C. ( FIG. 11 ), and at the rate of heating 100° C./min shows single peak of endotherm at 120° C. ( FIG. 12 ).
[0057] The thermogravimetric analysis exhibits one-step weight loss of 4.14% between temp 80° C. to 140° C. ( FIG. 6 ).
EXAMPLE 2
Preparation of Lamivudine Form III
[0058] A suspension of the Lamivudine form-II (20.0) g in water (60.0 ml) was heated to 45° C. in 25 min to give a solution. The solution was cooled to 30° C. in 15 min. The mass was then cooled to 10° C. in 20 min and stirred for 1 h. The product was filtered and washed with IMS (2×10 ml) then dried in vacuum at 45° C. for 24 h. Yield=17 gms.
[0059] Powder X-ray diffraction pattern superimposable with that of form III as obtained in Example 1.
EXAMPLE 3
Preparation of Lamivudine Form III
[0060] A suspension of the Lamivudine form-II (20.0) g in water (60.0 ml) was heated to 45° C. in 25 min to give a solution. The solution was cooled to 30° C. in 30 min. The mass was then cooled to 10° C. in 20 min and stirred for 1 h. The product was filtered and washed with ethanol (2×10 ml), then dried in vacuum at 45° C. for 24 h. Yield=17 gms.
[0061] Powder X-ray diffraction pattern superimposable with that of form III as obtained in Example 1.
EXAMPLE 4
Preparation of Lamivudine Form III
[0062] A suspension of the Lamivudine form-II (10.0) g in water (30.0 ml) was heated to 45° C. in 20 min to give a clear solution. The solution was cooled to 30° C. in 15 min. The reaction mass was then cooled to 10° C. in 20 min and stirred for 1 h. The product was filtered and dried in vacuum at 45° C. for 24 h. Yield=8.5 gms.
[0063] Powder X-ray diffraction pattern superimposable with that of form III as obtained in Example 1.
EXAMPLE 5
Preparation of Lamivudine Form III
[0064] A suspension of the Lamivudine form-1 (10.0) g in water (30.0 ml) was heated to 45° C. in 20 min to give a clear solution. The solution was then cooled to 10° C. in 10 min and stirred for 1 h. The product was filtered and dried in vacuum at 45° C. for 24 h. Yield=7 gms
[0065] Powder X-ray diffraction pattern superimposable with that of form III as obtained in Example 1.
EXAMPLE 6
Preparation of Lamivudine Form III
[0066] A suspension of the Lamivudine form-II (10.0) g in water (30.0 ml) was heated to 45° C. in 20 min to give a clear solution. The solution was then cooled to 10° C. in 10 min and stirred for 1 hr. The product was filtered and dried in vacuum at 45° C. for 24 hr. Yield=8 gm.
[0067] Powder X-ray diffraction pattern superimposable with that of form III as obtained in Example 1.
EXAMPLE 7
Preparation of Lamivudine Form III
[0068] A suspension of the Lamivudine form-II (50.0) g in water (150.0 ml) was heated to 45° C. in 17 min. to give a clear solution. The solution was cooled slowly to 30° C. in 1.0 hr 40 min. The product was then cooled to 10° C. in 10 min and stirred for 1 h. The product was filtered and dried in vacuum 1.0 mm at 45° C. for 24 h. Yield=44 gm
[0069] Powder X-ray diffraction pattern superimposable with that of form III as obtained in Example 1.
EXAMPLE 8
Preparation of Lamivudine Form III
[0070] A suspension of the Lamivudine form-II (20.0) g in water (80.0 ml) was heated to 45° C. in 25 min to give a clear solution. The solution was cooled slowly to 30° C. in 55 min. The product was then cooled to 10° C. in 5 min and stirred for 1 h at the same temperature. The product was filtered and dried in vacuum for 24 hr at 50-55° C. Yield: 18 gm.
[0071] Powder X-ray diffraction pattern superimposable with that of form III as obtained in Example 1.
EXAMPLE 9
Preparation of Lamivudine Form III
[0072] A suspension of the Lamivudine form-II (20.0) g in water (100.00) was heated to 45° C. in 25 min to give a clear solution. The solution was cooled slowly to 30° C. in 55 min. The product was then cooled to 10° C. in 5 min and stirred for 1 h at the same temperature. The product was filtered and dried in vacuum for 24 hr at 50-55° C. Yield 18.7 gm.
[0073] Powder X-ray diffraction pattern superimposable with that of form III as obtained in Example 1.
EXAMPLE 10
Preparation of Lamivudine Form III
[0074] A suspension of lamivudine (Form I or Form II or mixture thereof) (35 gm) in water (105 ml) was heated to 45° C. in 17 minutes to give a clear solution. The solution was cooled slowly to 37° C. in 50 minutes. The solution was seeded with lamivudine form III. The mixture was then cooled to 10° C. in 10 minutes and stirred for one hour. The product was filtered and dried in vacuum at 45° C. for 24 hours. Yield 32 gm.
[0075] Powder X-ray diffraction pattern superimposable with that of form III as obtained in Example 1.
EXAMPLE 11
Preparation of Lamivudine Form III
[0076] A suspension of the Lamivudine form-II (5.0 gm) in water (5.0 ml) was stirred at 25° C. for 48 hours. The suspension was cooled and stirred at 10° C. for one hour. The product was filtered and then dried under vacuum at 45° C. for 24 hours. Yield=4.5 gms
[0077] Powder X-ray diffraction pattern superimposable with that of form III as obtained in Example 1.
EXAMPLE 12
Preparation of Lamivudine Form III
[0078] A suspension of the Lamivudine form-I (2.0 gm) in water (2.0 ml) was stirred at 25° C. for 24 hours. The suspension was cooled and stirred at 10° C. for one hour. The product was filtered and then dried under vacuum at 45° C. for 24 hours. Yield=1.6 gms
[0079] Powder X-ray diffraction pattern superimposable with that of form III as obtained in Example 1.
EXAMPLE 13
Preparation of Lamivudine Form I
[0080] A suspension of the Lamivudine (10.0) g in water (30.0 ml) was heated to 45° C. in 30 min to give a solution. The solution was cooled to 30° C. in 0.5 min. The product was crystallized as an unstirrable mass. This was broken up and suspension stirred at 10.0° C. for 1 hr. The product was filtered and washed with IMS (2×5 ml) then dried in vacuum at 45° C. for 24 hr. Yield=6.0 gm
[0081] IR Spectra [Nujol Mull] (cm −1 ): 3356, 3199, 2923, 2854, 1639, 1611, 1461, 1402, 1376, 1309, 1288, 1252, 1196, 1166, 1145, 1107, 1052, 970, 932, 839, 786, 720 ( FIG. 13 ).
[0082] X-ray powder diffraction analysis shows peaks at about 5.20, 6.66, 8.53, 8.81, 9.65, 9.85, 10.15, 10.41, 11.27, 11.38, 11.63, 12.34, 12.60, 12.93, 13.22, 14.60, 15.01, 15.17, 15.67, 15.81, 16.51, 17.59, 17.98, 18.13, 18.72, 19.10, 19.30, 19.76, 21.79, 23.49, 23.71, 25.44, 25.90, 27.34, 29.46, 31.00±0.2 °2θ.
[0083] The differential scanning calorimetric analysis at the rate of heating 2° C./min shows first peak of endotherm at 123° C. and second at 177° C. ( FIG. 7 ), and at the rate of heating 100° C./min shows single peak of endotherm at 146° C. ( FIG. 8 ).
[0084] The thermogravimetric analysis exhibits one-step weight loss of 1.52% between temp 80° C. to 140° C. ( FIG. 4 ).
EXAMPLE 14
Preparation of Lamivudine Form I
[0085] A suspension of the Lamivudine (250.0 g) in the mixture of water (750.0 ml) and DNS (250.0 ml) was heated to 45° C. in 12 min to give a solution. The solution was cooled to 30° C. in 15 min and seeded with form I crystals. The product was then cooled to 10° C. in 30 min and stirred for 1 h. The product was filtered washed wished with 100 ml water DNS mixture (3:1) and dried in vacuum at 45° C. for 24 h. Yield: 220.0 gm.
[0086] Powder X-ray diffraction pattern superimposable with that of form I as obtained in Example 13.
EXAMPLE 15
Preparation of Lamivudine Form II
[0087] A suspension of the Lamivudine (10.0) g in ethanol (200.0 ml) was heated to refluxed to give a clear solution. The solution thus formed was subjected to distillation and about 100 ml of ethanol was distilled out at atmospheric pressure. The remaining solution was then cooled to 15° C. in 35 min. The suspension stirred at 15° C. for 1.0 hr. The product was filtered and washed with ethanol (10.0 ml) then dried in vacuum at 50° C. for 12 hr to get 8.2 gm.
[0088] IR Spectra [Nujol Mull] (cm −1 ): 3322, 3194, 2950, 2870, 1651, 1611, 1496, 1456, 1396, 1376, 1337, 1316, 1285, 1222, 1180, 1158, 1087, 1058, 1030, 918, 851, 806, 786, 723 ( FIG. 14 ).
[0089] X-ray powder diffraction analysis shows peaks at about 10.70, 12.17, 13.42, 14.30, 14.76, 15.86, 16.83, 17.55, 18.63, 19.68, 20.63, 21.44, 22.13, 22.60, 23.03, 24.44, 24.94, 25.70, 26.51, 27.68, 28.41, 28.93, 29.72, 30.67, 30.90, 31.30, 31.47, 31.99, 32.40, 32.59, 33.14, 34.01, 35.20, 35.49, 37.27, 38.46±0.2 °2θ.
[0090] The differential scanning calorimetric analysis at the rate of heating 2° C./min and 100° C./min shows single peak of endotherm at 177° C. ( FIG. 9 and FIG. 10 ).
[0091] The thermogravimetric analysis reveals that it is an anhydrous product. ( FIG. 5 ).
EXAMPLE 12
Pharmaceutical Formulations
(a) 150 mg Lamivudine Tablet
[0092]
[0000]
Ingredients per Tablets
Weight (mg.)
Lamivudine (Form III)
150
Microcrystalline cellulose NF
269.62
Sodium starch glyclolate NF
22.50
Colloidal silicon dioxide NF
2.25
Magnessium Stearate NF
5.63
Total Weight
450.00
[0093] Lamivudine (form III), microcrystalline cellulose, sodium starch glycolate and colloidal silicon dioxide were sieved and blended in octagonal for about 15 minutes. Sieved magnesium stearate was then added and blending continued for a further 2 minutes
[0094] The blend was compressed in standard tabletting equipment.
[0095] Analysis:
[0096] Tablet weight: 450 mg+5%
[0097] Thickness: 5.0-5.2 mm
[0098] Hardness: 150 to 200 N
[0099] Disintegration Time: 25 seconds.
[0100] % friability: 0.1%.
(b) Lamivudine Form III/Zidovudine Combination Tablets:
[0101]
[0000]
Ingredients per Tablets
Weight (mg.)
Intra-granular
Lamivudine (Form III)
150.00
Zidovudine
300.00
Dicalcium phosphate dihydrate NF
181.87
Sodium starch glyclolate NF
56.25
Purified water
Qs
Extra-granular
Sodium starch glycolate NF
18.75
Dicalcium phosphate dihydrate NF
37.50
Magnessium stearate NF
5.63
Coating
Opadry YS-1 7706G White
15
Total Weight
765.00
[0102] Lamivudine (form III), Zidovudine, sodium starch glycolate and dicalcium phosphate dihydrate were sieved and mixed in rapid mixer granulator for about 15 minutes. The drymixture obtained was granulated using purified water as granulating agent. The granules were then dried and sifted. Previously sifted sodium starch glycolate and dicalcium phosphate dihydrate blended with the dry granules in octagonal blend for 10 minutes. Previously sifted magnesium stearate was added to this blend and blending continued for further two minutes. The blend was compressed in standard tabletting equipment and then film coated with an aqueous suspension of Opadry YS-1 7706 G White to produce aesthetically acceptable tablets.
[0103] Analysis:
[0104] Tablet weight: 750 mg+10 mg
[0105] Thickness: 5.5-5.6 mm
[0106] Hardness: 120 to 130 N
[0107] Disintegration Time: 35 seconds (coats), 50 seconds.
[0108] % friability: 0.2%.
[0109] Dissolution in 0.1 N HCl, 50 rpm, paddle, 900 ml:
[0000]
Time (minutes)
Lamivudine (%)
Zidovudine (%)
5
80.9
81.1
10
86.2
87.8
20
92.0
95.2
30
96.0
100.4
40
96.7
101.5 | The disclosure herein relates to a new Lamivudine polymorphic form, methods of making the same, and pharmaceutical formulations thereof. A (−) cis-4-amino-1-(2-hydroxymethyl-1,3-oxathiolan-5-yl)-(1H)-pyrimidin-2-one in the form of monoclinic crystals has characteristic powder X-ray diffractogram, as disclosed herein, is disclosed along with a process for preparation of the same. A pharmaceutical composition in solid dosage unit form comprising a therapeutically effective amount of a new Lamivudine polymorphic form in combination with a pharmaceutically acceptable carrier is also disclosed along with a pharmaceutical composition useful for treating HIV infections in humans. | 2 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] Reference is made to German Application Serial No. DE 10 2011 112 290.0, filed Sep. 5, 2011, which application is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to an actuator having at least one control element which has thermally activatable transducer material and, as a result of the supply or dissipation of energy, changes from a first shape state into a second shape state, and having a mechanical energy store, which is functionally connected to the at least one control element and, when the control element is in the second shape state, it exerts on the control element a restoring force which returns the control element to the first shape state.
[0004] 2. Description of the Prior Art
[0005] Actuators having at least one control element which utilize thermally activatable transducer material are used to perform mechanical actuation in which the control element is to be deflected in a controlled, bidirectional manner along a movement trajectory, which in most cases corresponds to along a linear axis. For a multiplicity of technical, in particular control applications, control elements are used which utilize a shape memory alloy, often in the form of shape memory wires or plates.
[0006] Such control elements are generally activated either by the ambient temperature or by artificial thermoelectric stimulation. In the case of artificial thermoelectric stimulation, an electric voltage is applied to the control element including an electrically conductive shape memory alloy, (SMA), which voltage results in a flow of electric current along the control element producing a resistance-induced ohmic heat, which heats the control element.
[0007] As a result of the heating, SMA control elements generally undergo a change in shape, preferably in the form of a shortening or change in size, which is caused by a phase transformation between the martensitic low-temperature phase to the austenitic high-temperature phase. Many of the known shape memory alloys cannot perform any more work once the austenitic high-temperature phase has been achieved. In these cases an automatic reverse deformation once the shape has changed when the shape memory alloy is heated does not occur, even when the temperature is reduced.
[0008] In order to be able to perform work again in these cases, the control element must be returned to the starting state, in which an SMA must be cooled and also deformed back to the starting state by means of an external mechanical force. It should be noted that such a restoration of shape induced by a mechanical external force is also used for shape memory actuators which can be activated correspondingly by magnetic fields.
[0009] The mechanical restoration of SMA control elements which have been deflected once or deformed once by thermal activation, for example in the form of wires or wire bundles, takes place with the aid of restoring elements functionally connected to the control elements, for example in the form of springs or weights. During the switching process, the control element thus performed mechanical work induced by a change in travel, which is partially used to deform the corresponding restoring element, for example to tension a spring or to displace a weight, for example to lift a weight counter to gravity. During restoration, the mechanical energy stored in this manner is transmitted back to the control element, as a result of which the latter can be transferred to its starting state.
[0010] A further possibility for restoring SMA control elements to the starting state can also be achieved with a plurality of SMA control elements entering into alternating functional connections, in which the switching process of an SMA control element causes a corresponding restoration of another SMA control element. Restoring elements in the form of springs and weights can be omitted in this manner.
[0011] The prerequisite for complete restoration, which can also be achieved within a short time, of an SMA control element deformed by thermal activation depends critically on the ability to conduct away or dissipate the thermal energy necessary for the single deformation process in the form of heat out of the control element after the switching process.
[0012] To support the cooling process, the convection-induced heat removal process is supported in a manner known per se, for example with the aid of an external fan, as a result of which the convective cooling process is greatly supported and the cooling speed of the SMA control element can be increased, in order in this manner to allow a faster return to the starting state and thus a faster repeated switching or activation of the control element.
SUMMARY OF THE INVENTION
[0013] The invention utilizes an actuator having at least one control element which has thermally activatable transducer material and, as a result of the supply or dissipation of energy, changes from a first shape state into a second shape state, and having a mechanical energy store, which is functionally connected to the control element. When the control element is in the second shape state, a restoring force is exerted on the control element which returns the control element to the first shape state, in such a manner that the process of returning to the first shape state takes place faster than previously, so that the actuator has faster actuator reaction times, so that the control element can change to and from the first and second shape states in a very short time sequence.
[0014] An actuator is formed so that the mechanical energy store has an elastomer body, which at least in some regions is in direct physical and thermal contact with the control element. The elastomer body is also connected in a spatially fixed manner to the control element at at least two spatially separate regions along the control element, so that in the event of a change in shape of the control element, the elastomer body is subjected to a compression or an elongation which generates the restoring force.
[0015] The control element described below is entirely made from a thermally activatable transducer material, preferably of a thermally activatable SMA. Of course, control elements having transducer materials which can be activated in different ways are also conceivable. In these cases, the further embodiments of the invention can relate to thermally activatable regions of hybrid control elements.
[0016] Control elements of only thermally activatable shape memory alloys can have a wide variety of spatial shapes with the most widespread being wire- or plate-shaped SMA control elements in actuator systems. Regardless of the choice of shape and size of the thermally activatable control elements, the control elements should according to the invention be connected to an elastomer body so that the elastomer body undergoes a change in shape at the same time as the change in shape or change in travel of the control element, which cause compression or expansion work to be performed on the elastomer body, which is stored as elastic potential energy in the elastomer body. The elastic potential energy stored in the elastomer body in turn generates in the control element a restoring force directed counter to the direction of travel, which can transfer the control element back to the starting state.
[0017] In order to be able to use the change in shape of the elastomer body initiated by the change in travel of the SMA control element in the most direct manner possible and largely without losses in travel, at least two fasteners are used, which are connected to the control element in each case of two regions spaced apart from each other along the control element which are in addition connected in a fixed manner to the elastomer body which is joined in a form-fitting manner to the control element.
[0018] In this manner the fasteners can transmit compression or expansion forces to the elastomer body situated between the two fasteners in the event of a corresponding change in shape of the control element. Specific configurations of the fasteners are explained below in connection with the figures.
[0019] The elastomer body which is joined in a form-fitting manner to the control elements has sufficient elasticity owing to its mechanical properties that the elastomer body can follow the thermally activated deformations of the control element permanently and without damage. The heat produced by the electrical operation of the SMA control element can be absorbed directly and dissipated to the environment owing to the direct physical contact between the elastomer body and the control element. Since the elastomer body surrounds the control element at least in some regions in a jacket-like manner, preferably completely, the elastomer body can remove the heat from the control element effectively. In the same manner, in the event of activation initiated by ambient temperature, heat is removed from the SMA control element via the elastomer body surrounding the control element as soon as the ambient temperature falls below the activation temperature.
[0020] In a preferred embodiment, for the purpose of improved heat dissipation, the elastomer body is mixed with additional substances or particles which improve heat dissipation, such as boron nitride. Of course, additives such as metal powders, for example iron, copper, aluminium or silver powders, are also suitable. The addition of oxides such as zinc oxide or magnesium oxide are likewise suitable. Fiber fillers such as carbon fibers can also be incorporated in the elastomer body for the purpose of improved heat conduction. The elastomer body can also be mixed with graphite. The above addition of substances, in particular the addition of electrically conductive substances must be introduced into the elastomer body in a concentration and distribution such that the elastomer body itself does not become electrically conductive, in order to ensure electrical insulation of the elastomer body from the environment in this manner.
[0021] To support the heat removal process further, it is advantageous and also conceivable, in combination with or alternatively to the above measures, to provide the elastomer body with at least one cooling channel, through which a cooling medium, such as a cooling liquid, can be conducted.
[0022] It is also advantageous to shape the surface of the elastomer body which faces away from the control element and towards the environment in such a manner that it has surface structures which enlarge the surface area of the body and are configured and suited to improving heat exchange via the surface structures. Such surface structures can be selected to be in the form of cooling ribs, as are known from the field of internal combustion engines.
[0023] As some of the further exemplary embodiments will show, the elastomer body is also used as a deformation body, which causes the trajectory along which the change in travel of the actuator takes place to be predefined. In particular, if two or more SMA control elements which penetrate the respective elastomer body are used, different spatial deflections of the actuator can be enforced or achieved from the elastic properties of the elastomer body.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The invention is described below by way of example using exemplary embodiments and with reference to the drawings, without any limitation of the general inventive concept. In the figures:
[0025] FIG. 1 shows a cross section of an actuator formed according to the invention;
[0026] FIGS. 2 a and b show fasteners for fixing covering elements along the SMA control element;
[0027] FIGS. 3 to 6 show alternative configurations of the actuator formed according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0028] FIG. 1 shows a diagrammatic longitudinal section through an actuator formed according to the invention, which has a wire 1 made from a SMA for producing a change in travel. For the thermal activation of the SMA wire 1 , the wire is connected to a suitable current source (not shown). Alternatively, the SMA wire can also be induced to change shape as a result of the ambient temperature exceeding a defined activation temperature.
[0029] Along a section of the SMA wire 1 , an elastomer body 2 is provided in the form of a solid cylinder through which the SMA wire 1 runs centrally. The SMA wire 1 thus is in direct physical contact with the elastomer body 2 , which surrounds the former in a form-fitting manner. On both sides of the elastomer body 2 , fasteners 3 in the form of covering elements are provided, which are joined fixedly to the SMA wire 1 and also to the end faces of the elastomer body 2 . For the fixed joining of the covering elements 3 to the SMA wire, reference is made to the connection elements 4 , which are illustrated in FIGS. 2 a and b.
[0030] In the event of actuator activation, which takes place in response to a brief supply of current to the SMA wire 1 or by heating the SMA wire 1 by means of the ambient temperature, the SMA wire 1 contracts. Owing to the spatially fixed connection of the covering elements 3 to the wire 1 , the covering elements 3 are correspondingly moved together with the wire deformation and for their part compress the elastomer body 2 , which is located on both sides between the two covering element 3 and is correspondingly elastically deformed that is, compressed.
[0031] If, however, the temperature inside the SMA wire falls again after corresponding activation or cooling of the ambient temperature, a change in structure takes place inside the SMA wire 1 , by which the rigidity of the SMA wire 1 is reduced. The compressed elastomer body 2 can thus output its stored mechanical elastic potential or compression energy by relaxing in the form of a restoring force, which transfers the SMA wire 1 to the starting state and acts on both covering elements 3 with mutually opposite force directions.
[0032] FIGS. 2 a and b show a possibility with which the covering elements 3 shown in FIG. 1 can each be joined in a spatially fixed manner to the SMA wire 1 . Plastically deformable, sleeve-like connection elements 4 , which can be guided over the SMA wire 1 and positioned at any desired point along the wire are used for this. FIG. 2 a shows such a sleeve-like connection element 4 . In order to carry out permanent fixing which cannot move along the SMA wire 1 , the connection element 4 is plastically deformed in the longitudinal direction of the SMA wire 1 with the aid of a suitable crimping tool, so that the connection element 4 is securely joined to the SMA wire 1 by a combination of form-fitting and frictional force.
[0033] The plastically deformable connection element 4 illustrated in FIGS. 2 a and b is in each case connected fixedly to the SMA wire 1 on one side relative to the covering element 3 according to the position which can be seen in FIG. 1 . In the event of a corresponding shortening of the SMA wire 1 , both covering elements 3 thus move towards each other owing to in each case one-sided, fixed connection to the SMA wire 1 and thus compress the elastomer body 2 situated in between.
[0034] In contrast to the central arrangement of the SMA wire 1 along the cylindrical elastomer body 2 in FIG. 1 , as a result of which the change in travel of the actuator runs in the longitudinal direction of the SMA wire 1 , the SMA wire 1 in the exemplary embodiment according to FIGS. 3 a and b is arranged eccentrically to the cylinder axis A of the cylindrical elastomer body 2 . In this example too, the elastomer body 2 is connected fixedly to the SMA wire 1 via the covering elements 3 and the connection elements 4 .
[0035] In the event of a thermally induced activation of the SMA wire 1 , which results in a shortening of the wire 1 . In the case of the actuator according to FIG. 3 a lateral pivoting movement occurs, which the actuator executes owing to the geometry and elastic deformation properties of the elastomer body 2 . The movement trajectory which the actuator follows in the case illustrated in FIG. 3 is thus produced from the eccentric attachment of the SMA wire 1 relative to the axis of symmetry A of the elastomer body 2 and from the shape, size and elastic deformation properties of the elastomer body 2 .
[0036] To return the thermally activated SMA wire 1 to the starting state, the elastomer body 2 is used, which generates a restoring force which restores the starting state owing to the deformation.
[0037] If only one SMA wire 1 is used to change the travel of the actuator, the travel trajectory is predefined in an unchanging manner by the design of the actuator. If, however, two or more SMA wires, which can be thermally activated separately from each other, are provided within a single actuator, individual travel trajectories can be produced. FIG. 4 a illustrates an actuator of this type, which provides two separate SMA wires 1 and 1 ′ along an elastomer body 2 . The SMA wires 1 and 1 ′ are connected in the same manner to the elastomer body 2 via connection elements 4 and covering elements 3 , as is explained in the case example according to FIG. 1 . Both SMA wires 1 and 1 ′ are each attached eccentrically to the cylinder axis A of the elastomer body 2 . A bidirectional pivoting of the actuator can be achieved depending on the activation of the SMA wires 1 and 1 ′. In the case example in FIG. 4 b , it is assumed that the SMA wire 1 is thermally activated and thus shortened, whereas the SMA wire 1 ′ does not undergo a corresponding activation. In this manner the actuator pivots to the left. In contrast, in case example 4 c the SMA wire 1 ′ is thermally activated, whereas the SMA wire 1 remains without activation. The actuator is thereby pivoted to the right. Of course, it is possible to provide more than two such SMA wires inside an elastomer body to achieve multidirectional pivoting of the actuator.
[0038] A further exemplary embodiment is illustrated in FIG. 5 , which has an SMA wire 1 which penetrates the elastomer body 2 in different spatial directions. In this case the SMA wire 1 is in each case fixed to an upper covering element 3 by the above-explained connection elements 4 . Only a deflection element 5 is attached to the lower covering element 3 , around which deflection element the SMA wire 1 is deflected. With this design of the actuator, it is possible depending on the position of the deflection element 5 relative to the connection elements 4 attached to the covering element 3 , to achieve increases in travel.
[0039] A further variant for influencing the travel is shown in the sequence diagrams according to FIGS. 6 a, b and c . Here the lower end of the elastomer body 2 is connected to a lower supporting face 6 , in which the SMA wire 1 is fixed on one side. In the same manner as in the exemplary embodiment according to FIG. 1 , the SMA wire 1 runs centrally to the otherwise cylindrical elastomer body 2 . Of course, spatial shapes which deviate from the cylindrical shape are also possible to form the elastomer body 2 , such as shapes of oval or polygonal cross section.
[0040] The upper end of the elastomer body 2 is connected to a covering element 3 and a connection element 4 which has already been explained. In the event of corresponding activation of the SMA wire 1 , the SMA wire is shortened and together with the covering element 3 comes into contact with a lateral counterbearing 7 , causing the actuator is bent to the side, at least in the upper region (see FIG. 6 b, c ). Such mechanical counterbearings 7 can be used to provide externally induced jumps in rigidity, which influence the movement process of the actuator and allow complex control processes in which several partial movements of the same SMA wire 1 can be executed in parallel or sequentially during a switching process.
[0041] In the same manner as the application or provision of an externally induced jump in rigidity by use of the counterbearing 7 illustrated in FIG. 6 , such jumps in rigidity can also be provided inside the elastomer body 2 so that suitable rigidity regions which come into contact with each other are created inside the elastomer body.
[0042] The material from which the elastomer body 2 is formed is in principle selected from an electrically non-conductive material so that electrical short circuits can be avoided, using particular in actuators which can be activated electrically.
[0043] Typically, elastomer bodies can be produced using a casting process, during which the at least one SMA wire can be inserted into the region of the elastomer body. Alternatively, a place-holder for an appropriate cut-out can be provided during the casting process, so that the SMA wire can be introduced into the elastomer body after the latter has been produced. It is likewise possible to integrate the at least one SMA wire in the elastomer body by means of subsequent drilling or penetration processes.
[0044] Particularly suitable materials for the elastomer body are elastomer-like materials based on rubber or silicone. Foamed elements having suitable elastic properties can also be used.
[0045] As already mentioned in connection with the exemplary embodiment illustrated in FIG. 6 , inhomogeneous rigidity distributions can be carried out within the elastomer body to provide complex actuator deformations, for example by embedding additional rigidity elements inside the elastomer body.
[0046] It is also possible to integrate electronic or mechanical components such as sensors, RFID chips, magnetic bodies or the like during the process of producing the elastomer body in order in this manner to carry out monitoring of any type, for example temperature monitoring, identification for protection against plagiarism etc.
LIST OF REFERENCE SYMBOLS
[0000]
1 Control element, SMA wire
2 Elastomer body
3 Covering element
4 Connection element
5 Deflection element
6 Supporting face
7 Mechanical counterbearing | The invention is an actuator which includes at least one control element which has thermally activatable transducer material and which, in response to the supply or dissipation of energy, changes from a first shape state into a second shape state, and a mechanical energy store, which is functionally connected to the control element and, when the control element is in the second shape state, exerts on the control element a restoring force which returns the control element to the first shape state. The mechanical energy store includes an elastomer body, which at least in some regions is in direct physical and thermal contact with the control element, the elastomer body is connected in a spatially fixed manner to the control element in at least two spatially separated joining regions along the control element. | 5 |
CROSS-REFERENCE
[0001] The present application claims the benefit of and priority to U.S. Application No. 61/622,290 filed Apr. 10, 2012 the disclosure of which is hereby incorporated by reference.
BACKGROUND
[0002] Machines and tools for working soil are useful in connection with a variety of endeavors including athletic field maintenance, maintenance of arenas, tracks, and competition courses for horses and other animals, landscaping, runoff and erosion control, installation and maintenance of lawns and seedbeds, grading, and scarification and smoothing of soil among others. While present soil working machines and tools offer a number of benefits, they suffer from significant limitations and shortcomings Applications such as landscaping, athletic field maintenance, race tracks, equestrian courses, and show rings for horses and other animals may present a number of challenges including the need for a high degree of uniformity and consistency, the need to navigate tight or complex geometries, the need to work unconventional soil compositions or compositions of other media such as engineered or treated soil media used, for example, in equine competition arenas as well as a variety of other engineered, synthetic or augmented media all of which are collectively referred to as soil for the sake of concise description, the need for operator safety and ease of operation. There is a significant heretofore unmet need for the self-propelled soil working machines disclosed herein.
DISCLOSURE
[0003] For the purposes of clearly, concisely and exactly describing exemplary embodiments of the invention, the manner and process of making and using the same, and to enable the practice, making and use of the same, reference will now be made to certain exemplary embodiments, including those illustrated in the figures, and specific language will be used to describe the same. It shall nevertheless be understood that no limitation of the scope of the invention is thereby created, and that the invention includes and protects such alterations, modifications, and further applications of the exemplary embodiments as would occur to one skilled in the art to which the invention relates.
SUMMARY
[0004] Unique self-propelled soil working machines are disclosed. In certain exemplary embodiments the self propelled soil working machine includes a tool carrier which is actively adjustable to provide variable downward force on a soil working tool via a suspension element which is further passively responsive to accommodate motion of the tool in response to external force. In certain exemplary embodiments, the tool carrier is configured to adjust the working depth and pitch of the tool. Further embodiments, forms, objects, features, advantages, aspects, and benefits shall become apparent from the following description and figures.
BRIEF DESCRIPTION OF THE FIGURES
[0005] FIG. 1 is a first perspective view of an exemplary self-propelled soil working machine carrying an exemplary soil working tool.
[0006] FIG. 2 is a second perspective view of the exemplary self-propelled soil working machine of FIG. 1 .
[0007] FIG. 3 is third perspective view of the exemplary self-propelled soil working machine of FIG. 1 with the soil working tool in a raised position.
[0008] FIG. 4 is fourth perspective view of the exemplary self-propelled soil working machine of FIG. 1 with the soil working tool in a lowered position contacting the ground.
[0009] FIG. 5 is fifth perspective view of the exemplary self-propelled soil working machine of FIG. 1 with the soil working tool in a lowered position contacting the ground and the springs compressed.
[0010] FIG. 6 is a perspective view of an exemplary self-propelled soil working machine carrying a second exemplary soil working tool.
DETAILED DESCRIPTION
[0011] With reference to FIGS. 1-4 there are illustrated several views of an exemplary self-propelled soil working machine 100 . Machine 100 includes a chassis 102 supported by front wheels 104 and rear wheels 106 which contact a ground surface 101 and support chassis 102 . In the illustrated embodiments chassis 102 is configured as a frame based chassis. It shall be appreciated, however, that other embodiments comprise a partial frame chassis, unibody chassis, or other types of chassis or support structures that are configured to be supported by ground contacting wheels or other ground contacting members and coupled with one or more soil working tools.
[0012] In the illustrated embodiments front wheels 104 are configured as caster type wheels which preferably are rotatable 360 degrees relative to chassis 102 . It shall be appreciated that a variety of differently configured front wheels may be utilized including, for example, front wheels provided on an axle, rack and pinion assembly, or other types of front end steering assembly and/or front end drive assembly. It shall be further appreciated that additional embodiments may include only a single front wheel, a greater number of front wheels, or may include ground surface contacting elements other than wheels, such as treads or tracks. While front wheels 104 are non-driven wheels in the illustrated embodiment, it shall be appreciated that other embodiments comprise one or more driven front wheels configured to provide at least part of the propulsion to the vehicle.
[0013] In the illustrated embodiments rear wheels 106 are coupled with a machine prime mover (not visible in the illustrated views). In a preferred embodiment the prime mover comprises an internal combustion engine configured to drive a hydraulic pump flow coupled with a hydraulic drive system configured to provide torque to rear wheels 106 . Exemplary hydraulic drive systems may include elements such as high pressure accumulators, low pressure reservoirs, secondary pumps, gearboxes, collectors and/or differentials. In other embodiments the prime mover is configured as an internal combustion engine configured to provide driving torque through an output shaft. In other embodiments the prime mover comprises an electric motor configured to provide output torque. The electric motor may be powered by a battery or other power storage source, by a generator driven by an internal combustion engine or a combination thereof.
[0014] In the illustrated embodiments each of rear wheels 106 is independently controllable and drivable in a forward or reverse direction, though other embodiments may comprise different drive wheel arrangements including front wheel drive arrangements, all wheel drive and four wheel drive arrangements, to name several non-limiting examples. Certain embodiments may comprise only a single rear wheel or a greater number of rear wheels or other ground contacting members.
[0015] With continuing reference to FIGS. 1-4 , chassis 102 supports an operator station 112 which includes a standing platform (not visible in the illustrated views) and a guard rail 114 positioned at the aft end of machine 100 adjacent the standing platform. Controls 150 are positioned to be manipulatable by an operator occupying the operator station in order to control movement or propulsion of the machine 100 as well as the positioning of one or more tools carried by the vehicle as further described hereinbelow.
[0016] In the illustrated embodiments machine 100 is configured as a substantially zero-turning radius machine, however it shall be appreciated that in additional embodiments the machine may be configured in a variety of other forms including, for example, a tractor, an ATV, or another type of wheeled or treaded machine. Furthermore, in certain embodiments, the operator station 112 may comprise an operator seat instead of or in addition to a standing platform. In certain embodiments the operator station 112 may be omitted and the machine may be controlled remotely using a separate operator control station in wireless communication with a controller provided on the machine 100 and configured to control movement or propulsion of the machine 100 as well as the positioning of one or more tools carried by the vehicle.
[0017] Chassis 102 is configured to support a soil working tool assembly 120 . In the illustrated embodiments, soil working tool assembly 120 comprises a finishing comb 138 including a plurality of finishing teeth, and a plurality of scarifying shanks 132 and scarifying tips 134 . It shall be appreciated that for clarity of illustration only one of the scarifying shanks 132 and one of the scarifying tips 134 are labeled with reference numerals. Finishing comb 138 is coupled with angle iron 136 , for example, by bolting, welding or with other types of connections. It shall be appreciated that angle iron 136 is but one example of a bracket structure to which one or more soil working tools may be coupled and that other embodiments comprise different tool mounting structures, or no tool mounting structures at all with direct tool connection to one or more linkage elements.
[0018] Scarifying shanks 132 are coupled with pockets 133 (only one of which is labeled with a reference numeral for clarity of illustration) which are in turn coupled with angle iron 136 . These couplings may be provided through a variety of techniques including bolting, welding, connection pins, clamps, or various other techniques. Collectively, the finishing comb 138 , angle iron 136 , pockets 133 , and scarifying shanks 132 and scarifying tips 134 comprise one example of a tool assembly which may be used in connection with machine 100 . It shall be appreciated that a variety of other configurations of tool assemblies may also be utilized in connection with machine 100 , including those examples described further herein below.
[0019] Exemplary elements connecting tool assembly 120 and chassis 102 will now be described. The tool assembly 120 is coupled with a pulling linkage 130 at a pivotal coupling 153 which rotates or pivots generally in the directions indicated by arrow R 3 . Pulling linkage 130 is coupled with chassis 102 at pivotal coupling 151 which rotates substantially in the directions indicated by arrow R 4 . Pulling linkage is configured to provide a force vector component to the tool assembly in the forward or reverse directions generally indicated by arrow X-X of the direction legend illustrated in FIGS. 3 and 4 as the machine is propelled forward or backward. A force vector component generally in the direction of arrow Y-Y of the direction legend illustrated in FIGS. 3 and 4 may also be provided, for example, during turning of the machine. Regardless of the particular direction, the pulling linkage provides one or more force vector components providing working force to the tool assembly 120 . Furthermore, the rotation permitted by pivotal couplings 151 and 153 accommodates both adjustment of the height and pitch of the tool assembly 120 relative to the plane defined by arrows X-X and Y-Y of the direction legend illustrated in FIGS. 3 and 4 .
[0020] The tool assembly is further connected to a suspension 125 at pivotal coupling 156 . The suspension 125 is in turn connected to a rocker 124 at pivotal coupling 155 . Rocker 124 is further coupled with chassis 102 at pivotal coupling 154 . Pivotal coupling 156 permits rotation of the tool assembly substantially in the direction indicated by arrow R 5 . Pivotal coupling 155 permits rotation of the rocker 124 relative to the suspension 125 substantially in the direction indicated by arrow R 2 . Pivotal coupling 154 permits rotation of the rocker 124 relative to the chassis 102 substantially in the direction indicated by arrow R 1 .
[0021] In the illustrated embodiments the suspension 125 is configured as a pair of telescoping cylinders in combination with springs 126 which are compressible between spring mounts 128 through relative motion of the telescoping cylinders. It shall be appreciated that a variety of other suspensions may be utilized in various embodiments in addition to or instead of the illustrated configuration including shock absorbers, elastomeric suspension elements, compressible members, pneumatic suspension elements, hydraulic suspension elements, other spring arrangements and combinations of the foregoing and/or other suspension elements. It shall be further appreciated that a variety of spring mounts may be utilized. In the illustrated embodiments spring mounts 128 are crimped or compressed in place relative to respective shafts or cylinders of a telescoping assembly. In certain embodiments the spring mounts may alternatively or additionally be welded, bonded, bolted or otherwise fixedly coupled with respective suspension elements. Certain embodiments comprise spring mounts adjustably coupled with respective suspension elements, for example, through an axial threaded connection which may utilize one or more lock nuts or other locking members, or by a set screw, pin or bolt.
[0022] The tool assembly is further coupled with an actuator 142 at pivotal coupling 157 . Actuator 142 is coupled with chassis 102 at pivotal coupling 152 . In the illustrated embodiments actuator 142 is configured as a hydraulic cylinder which is laterally displaceable in the directions indicated by arrow L 2 . The operator controls 150 may be configured to control the supply of pressurized hydraulic fluid to actuator 142 to control its position. The tool assembly is connected to the rocker assembly by a chain 121 via a V-bracket 123 . The rocker 124 is coupled with an actuator 140 at pivotal coupling 160 . Actuator 140 is coupled with the chassis 102 at a further pivotal coupling (not illustrated). In the illustrated embodiments actuator 140 is configured as a hydraulic cylinder which may be controlled in the same or similar fashion as actuator 142 . It shall be appreciated that either or both of actuators 140 and 142 may be provided in different configurations, for example, as ratchets, top links or other actuators configured to provide appropriate displacement and force. It shall further be appreciated that either or both of actuators 140 and 142 may be omitted in certain embodiments. In such embodiments vertical adjustment of a tool assembly is preferably, though not necessarily, provided by actuators configured to adjust other structural elements of a machine, for example, adjustable wheel suspension elements configured to raise or lower a chassis, frame or other structure supporting, directly or indirectly a tool assembly, or via a variety of other actuators.
[0023] In the illustrated embodiments actuator 140 is selectably controllable to expand and contract in the direction generally indicated by arrow L 1 effective to cause rocker 124 to rotate about pivotal coupling 154 in the direction generally indicated by arrow R 1 . Rotation of the rocker 124 is effective to raise and lower the tool assembly 120 with the chain 121 over a first predetermined range from a maximum height to the point at which the tool assembly 102 contacts the ground surface 101 underlying the machine 100 . At this point the further rotation of the rocker 124 is effective to vary the amount of downward force applied to the tool assembly 120 by varying the compression of springs 126 . The suspension 125 further accommodates movement of the tool assembly in response to external force applied thereto, for example, if the tool assembly contacts an obstruction such as a rock or other structure located in a soil medium being worked.
[0024] It shall be appreciated that chain 121 is one example of a weight lifting structure that may be utilized to raise and lower a soil working tool or tool assembly. Structures such as cables, jointed linkages and other structures that limit relative displacement of a tool relative to a support structure to allow lifting through actuation in one direction, and deform, bend, flex, move or otherwise accommodate movement
[0025] Actuator 142 is selectably controllable to expand and contract in the direction generally indicated by arrow L 2 effective to cause tool assembly 120 to rotate about pivotal coupling 153 in the direction generally indicated by arrow R 3 . In this manner the pitch of the tool assembly to the plane defined by arrows X-X and Y-Y of the direction legend illustrated in FIGS. 3 and 4 may be varied.
[0026] With reference to FIG. 3 there is illustrated the machine 100 with the tool assembly 120 configured in a raised position along vertical axis Z-Z. Rocker 124 is rotated upward or counterclockwise relative to FIG. 4 (described below) effective to lift the tool assembly 120 with chain 121 . In this position, the spring 126 of suspension 125 will apply a fixed force to the tool assembly, which could be substantially zero force or a predetermined preload force. The preload force may be adjusted by varying the length of the chain 121 to preload springs 126 by a desired amount or additionally or alternatively by setting the position of spring mounts 128 and/or their respective supporting structures either at the time of assembly or through adjustment mechanisms provided in certain embodiments. From the configuration illustrated in FIG. 3 , rocker 124 may be counterclockwise to further raise the tool assembly 120 or clockwise to lower the tool assembly 120 . Once the tool assembly contacts a surface or structure underlying the machine, further clockwise rotation may be applied to vary the downward force vector component by compressing the springs 126 of the suspension to increase this force, or expanding them to decrease this force.
[0027] With reference to FIG. 4 there is illustrated the machine 100 configured with the tool assembly 120 in a lowered position along vertical axis Z-Z. In the configuration of FIG. 4 , the tool assembly 120 has been lowered to the point of contacting the ground, but the springs 126 remain in the same state as discussed above in connection with FIG. 3 , either with substantially zero compression or a desired amount of preload. Rocker 124 is rotated downward or clockwise relative to FIG. 3 effective to lower the tool assembly 120 with chain 121 . In this position, the spring 126 of suspension 125 will upon initial contact with the ground surface 101 apply a relatively small, initial magnitude or a substantially zero initial magnitude of downward force vector component to the tool assembly. The magnitude of the downward force vector component may be increased by further rotation of rocker 124 as described below in connection with FIG. 5 . Simultaneously the suspension 125 may accommodate passive movement of the tool assembly 120 in combination with the active adjustment of force.
[0028] With reference to FIG. 5 there is illustrated the machine 100 configured with the tool assembly 120 in a lowered position along vertical axis Z-Z. In the configuration of FIG. 4 , the tool assembly 120 has been lowered to the point of contacting the ground and the springs 126 remain have been compressed by further rotation of the rocker relative to FIG. 4 . Rocker 124 is rotated downward or clockwise relative to FIG. 4 effective to compress the springs 126 . In this position, the spring 126 of suspension 125 will apply an adjustable downward force vector component to the tool assembly. The magnitude of the downward force vector component may be increased by further clockwise rotation of rocker 124 or decreased by further counterclockwise rotation of rocker 124 . Simultaneously the suspension 125 may accommodate passive movement of the tool assembly 120 in combination with the active adjustment of force.
[0029] With reference to FIG. 6 there is illustrated an additional exemplary self-propelled soil working machine 200 coupled with a second exemplary soil working tool assembly 220 . In the illustrated embodiment machine 200 includes substantially the same features as machine 100 described in connection with FIGS. 1-5 above with the exception of tool assembly 220 . For the sake of brevity and clarity of illustration the corresponding elements of machine 200 have not all been numbered. Tool assembly 220 includes finishing comb 138 and pockets 133 coupled with angle iron 136 , and further includes profile blade 222 which includes a plurality of support struts 223 received by and coupled with respective pockets 133 . Further details of profile blade 222 are described in U.S. patent application Ser. No. 13/158,760 filed Jun. 13, 2011, the disclosure of which is hereby incorporated by reference.
[0030] It shall be appreciated that tool assemblies 120 and 220 are but two examples of tool assemblies including soil working tools which may be coupled with and carried by the exemplary soil working machines disclosed herein. Further examples of such tool assemblies include leveling blades, rolling baskets, rock teeth, hydraulic rippers, grooming rods, pin or post arrays, brushes, brooms, and finishing mats to name several non-limiting examples. Further details and examples of soil working tools and tool assemblies which may be coupled with and carried by the exemplary soil working machines disclosed herein include those disclosed in the above referenced U.S. patent application Ser. No. 13/158,760, and U.S. Pat. Nos. 7,540,331, 7,478,682, 7,066,275, 7,055,698, 6,739,404, and 5,806,605, and U.S. Reissued Pat. No. RE39889 E. The aforementioned patents and applications are hereby incorporated by reference.
[0031] Additional aspects according to a number of exemplary embodiments will now be described. Certain exemplary embodiments include apparatuses comprising a self-propelled soil working machine including a frame and an operator station, front and rear ground supporting wheels coupled with the frame with a least one of the front and rear wheels configured to propel the machine, a linkage coupled with the frame and coupled with a soil working tool, the soil working tool being adjustably positioned by the linkage rearward of the front wheels and forward of the rear wheels, the linkage including a suspension element accommodating movement of the tool in response to external force, and an adjustment mechanism coupled with the linkage and configured to adjust the linkage effective to emulate the addition or subtraction of weight exerting downward force on the tool.
[0032] In certain forms the linkage further comprises a lifting element coupled with and extending between the tool and the frame, the lifting element configured to selectably raise and lower the tool and to limit movement of the tool relative to the suspension element in a first direction.
[0033] In certain forms the linkage further comprises a rocker pivotally coupled with the frame at a first connection, pivotally coupled with the adjustment mechanism at a second connection, and pivotally connected with the suspension element at a third connection.
[0034] In certain forms the lifting element comprises a chain, a cable, or a jointed assembly coupled with and extending between the rocker and the tool.
[0035] In certain forms the suspension element comprises a first member, a second member displaceable relative to the first member, and a spring coupled with the first member and the second member.
[0036] In certain forms the adjustment mechanism comprises an actuator configured to provide positive and negative vertical movement of the tool via the linkage.
[0037] In certain forms the actuator comprises a hydraulic actuator, a ratchet, or a top link.
[0038] In certain forms the linkage comprises a plurality of suspension elements.
[0039] In certain forms the plurality of suspension elements are pivotally coupled at respective first ends with the tool and pivotally coupled at respective second ends with a rocker, the rocker being pivotally coupled with the frame.
[0040] In certain forms the linkage comprises a three point connection element rotatably coupled with the frame, the linkage, and the actuator.
[0041] Certain forms further comprise tool position controls configured to be manipulatable by an operator from the operator station.
[0042] Certain forms further comprise a second adjustment mechanism configured to vary pitch of the tool.
[0043] In certain forms the second adjustment mechanism comprises a second actuator pivotally coupled with and extending between the frame and the tool.
[0044] In certain forms the machine is a substantially zero turning radius machine or a tractor. In certain forms the operator station comprises a standing platform.
[0045] Certain exemplary embodiments include self-propelled soil working machines comprising a plurality of surface contact wheels carrying a chassis, a carrier assembly coupled with the chassis, the carrier assembly including a suspension coupled with the chassis and a soil working tool coupled with the suspension, an adjustment mechanism coupled with the carrier assembly and configured to adjust the position of the tool and to vary force applied to the tool at least in part based upon compression of the suspension.
[0046] In certain forms the carrier assembly comprises a rocker rotatably coupled with the chassis, the suspension, and the adjustment mechanism at respective first, second, and third couplings.
[0047] In certain forms the suspension comprises a first spring assembly, a second spring assembly, and a weight bearing coupling member rotatably coupled with the rocker and the tool.
[0048] In certain forms the first spring assembly, the second spring assembly, and the weight bearing coupling member are rotatably coupled with the rocker and the tool by separate couplings.
[0049] In certain forms the suspension comprises a lifting member configured to restrict motion of the tool relative to the suspension in a first direction and not to restrict motion of the tool relative to the suspension in a second direction substantially opposite from the first direction.
[0050] In certain forms the chassis comprises a frame structure connected with the plurality of surface contact wheels.
[0051] In certain forms the chassis comprises a unibody assembly.
[0052] Certain forms further comprise an operator station and controls configured to be manipulatable by an operator occupying the operator station to control the adjustment mechanism.
[0053] Certain exemplary embodiments include soil working machines comprising a plurality of support members configured to contact a ground surface under the machine, at least one of the ground contacting members being a driven member configured to propel the machine, a tool linkage rotatably coupled with the machine and including a tool mount and at least one compressible member, and an actuator coupled with the tool linkage, wherein the tool actuator may be configured to adjustably position the tool mount in a plurality of positions intermediate the front and the back of machine and to vary a downward force vector component applied to the tool mount.
[0054] Certain forms further comprise an operator station coupled with the machine.
[0055] In certain forms, the operator station comprises a standing platform, or a seat.
[0056] In certain forms, the compressible member comprises a spring.
[0057] In certain forms the spring is configured to selectably apply variable force to the tool mount and the actuator is configured to vary said force.
[0058] In certain forms the actuator is configured to vary said force in accordance with Hooke's law.
[0059] In certain forms the tool linkage is configured in a belly mount configuration relative to the machine.
[0060] Certain forms further comprise a soil working tool coupled with the tool mount.
[0061] In certain forms the actuator is configured to raise and lower the tool.
[0062] In certain forms the actuator is configured to compress the compressible member effective to increase force applied to the tool when the tool is in contact with the ground surface under the machine.
[0063] In certain forms the actuator is configured to compress the compressible member effective to increase force applied to the tool only when the tool is in contact with the ground surface under the machine.
[0064] In certain forms the compressible member is configured to apply a pre-load force to the tool when the tool is not in contact with the ground surface under the machine.
[0065] In certain forms the pre-load force is variable by adjusting the length of a weight lifting linkage coupled with and extending between the tool and the machine.
[0066] It shall be understood that the exemplary embodiments summarized and described in detail above and illustrated in the figures are illustrative and not limiting or restrictive. Only the presently preferred embodiments have been shown and described and all changes and modifications that come within the scope of the invention are to be protected. It shall be appreciated that the embodiments and forms described below may be combined in certain instances and may be exclusive of one another in other instances. Likewise, it shall be appreciated that the embodiments and forms described below may or may not be combined with other aspects and features disclosed elsewhere herein. It should be understood that various features and aspects of the embodiments described above may not be necessary and embodiments lacking the same are also protected. As utilized herein, the term substantially is used to indicate that an acceptable margin or degree of variance or error falls within the literal scope of a precise term as would occur to one of ordinary skill in the art depending on the particular embodiment or application in question. Unless otherwise limited the terms connected, connector, coupling and coupled refer to and encompass any direct or indirect coupling, connection, attachment. In reading the claims, it is intended that when words such as “a,” “an,” “at least one,” or “at least one portion” are used there is no intention to limit the claim to only one item unless specifically stated to the contrary in the claim. When the language “at least a portion” and/or “a portion” is used the item can include a portion and/or the entire item unless specifically stated to the contrary. | Unique self-propelled soil working machines are disclosed. In certain exemplary embodiments the self propelled soil working machine includes a tool carrier which is actively adjustable to provide variable downward force on a soil working tool via a suspension element which is further passively responsive to accommodate motion of the tool in response to external force. In certain exemplary embodiments, the tool carrier is configured to adjust the working depth and pitch of the tool. Further embodiments, forms, objects, features, advantages, aspects, and benefits shall become apparent from the following description and figures. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The subject invention relates to a process for the preparation of polyoxyalkylene block polyethers. More particularly, the invention relates to a process for the preparation of block polyoxyalkylene polyethers having one or more polyoxyethylene blocks and at least one block derived from a higher alkylene oxide. The use of cesium hydroxide to catalyze the oxyethylation results in polyethers having enhanced properties.
2. Description of the Related Art
Polyoxyalkylene block polyethers are well known commercial products having many uses, the most important of which is their use as nonionic surfactants. Polyoxyalkylene block polyether surfactants generally have both hydrophobic and hydrophilic blocks, and are described, for example, by Lundsted in U.S. Pat. No. 2,674,619 and by Jackson and Lundsted in U.S. Pat. Nos. 2,677,700 and 3,036,118. These references also disclose the preparation of such polyoxyalkylene block polyethers by oxypropylating an initiator molecule possessing two or more active hydrogens in the presence of a basic catalyst such as sodium or potassium hydroxide. The polyoxypropylene hydrophobe is then oxyethylated to produce external hydrophiles, or, in certain cases, the oxypropylation and oxyethylation may be reversed to produce "reverse" non-ionic surfactants having an internal hydrophile and external hydrophobes.
Diblock polyoxyalkylene polyethers or triblock polyoxyalkylene polyethers capped on one end are also useful products. These products are generally prepared by sequentially oxyalkylating a monofunctional initiator molecule such as an alkanol or phenol. To prepare diblock polyethers by this method, the initiator is first reacted with a higher alkylene oxide, that is, one having three or more carbons. The resulting hydrophobe is then oxyethylated. In certain applications the oxyalkylation may be reversed. Triblock polyethers are similarly prepared, but with a third oxyalkylation utilizing the same alkylene oxide as used for the first oxyalkylation.
For example, a triblock polyoxyalkylene polyether may be conventionally prepared, as shown in the reaction scheme below, by first oxypropylating a difunctional initiator molecule followed by oxyethylation. In these reaction schemes, --OP-- and --PO-- represent oxypropyl residues derived from propylene oxide while --OE-- and --EO-- represent analogously derived oxyethyl groups. ##STR1## An analogous monofunctional, mono-capped triblock polymer may be prepared by starting with a monol, R--OH, such as methanol, butanol, or benzylalcohol and altering the oxyalkylation sequency as follows: ##STR2## Such mono-capped block polyethers where the cap is joined to the block polyether by an ether linkage are hydrolytically stable and have been shown to possess different physical and chemical properties as compared to their non-capped analogues including modified surface activity and increased thermal stability.
The polyoxyalkylene polyethers described above have proven useful in numerous applications, particularly those requiring surface active properties such as detergents, foaming and defoaming agents, emulsifying and dispersing agents, and as thickeners in aqueous systems. However, despite their great utility, the methods of preparation previously described never results in a single, uniform product molecule, but in a cogeneric mixture containing molecules with widely varying total molecular weights as well as widely varying hydrophobe and hydrophile weights. This is particularly true as the molecular weights increase. Although it is well known that block polyether surfactants having uniform, narrow molecular weights and compositions possess properties markedly different from those of ordinary commercial products, it has been impossible to prepare such specialty products without inordinate expense.
It has now been surprisingly discovered that polyoxyalkylene block polyethers having narrow molecular weight distribution, uniform composition, and unexpectedly low levels of unsaturation may be simply and economically prepared through the use of cesium hydroxide catalysis for at least the oxyethylation portion of the polyether synthesis, and preferably for both oxyethylation and oxypropylation.
The use of cesium hydroxide as a polyoxypropylation catalyst has been proposed in U.S. Pat. No. 3,393,243. According to this reference, the use of cesium hydroxide as opposed to conventional sodium or potassium hydroxide catalysts in the synthesis of polyoxypropylene glycols prevents the elimination reaction at the polyether chain terminus, which ordinarily results in forming allylic unsaturation and, at the same time, lowers and broadens the molecular weight of the product polyoxypropylene glycols.
A mechanism for the elimination disclosed in U.S. Pat. No. 3,393,243 is discussed in Ceresa, Block and Graft Copolymerization, vol. 2, published by Wiley-Interscience at page 18. The mechanism apparently involves hydrogen abstration via a specific cyclic transition state which may be represented as follows: ##STR3## The unsaturation formed increases as a direct function of equivalent weight. Eventually a point is reached wherein further propylene oxide addition fails to increase the molecular weight.
When oxyethylation rather than oxypropylation is performed, as in the preparation of block polyethers, the use of cesium hydroxide as a catalyst has not been contemplated. The reason for this is that while it is readily conceived that polyoxypropylene glycols may react by the above mechanism, the same cannot be true for polyoxyethylene glycols or for oxyethylated polyoxypropylene glycols containing more than one oxyethyl group. Thus, until now, such block polyethers have been prepared with less expensive sodium and potassium hydroxide catalysts.
For example, when a single oxyethyl group is added to a polyoxypropylene glycol, the elimination mechanism may be written thusly: ##STR4## However, when more than one oxyethyl group is present, the requisite transition state cannot be achieved, and thus it had not been thought that the elimination products could affect in the polymerization reaction: ##STR5## Consequently, no eIimination, no unsaturation formation, and therefore no lowering of the polyether molecular weight is expected during ethylene oxide addition and, in fact, none has been detected heretofore.
SUMMARY OF THE INVENTION
It has now been surprisingly discovered, contrary to previous belief, that unsaturation is produced not only during the preparation of polyoxypropylene glycols during oxypropylation of a suitable initiator, but is also formed during oxyethylation as well. There is at present no accepted mechanism which to attribute this formation of unsaturation during ethylene oxide addition. It has further been discovered that cesium hydroxide is effective in lowering the amount of unsaturation formed during ethylene oxide addition and, at the same time, producing block polyethers with narrow molecular weight distribution and uniform composition.
BRIEF DESCRIPTION OF THE DRAWING
The drawing, FIG. 1, illustrates the narrower molecular weight distribution and higher overall molecular weight, as measured by gel permeation chromatography, of copolymer polyethers prepared in accordance with the process of the subject invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The polyoxyalkylene block polyethers of the subject invention are prepared in the conventional manner, except that cesium hydroxide is utilized as the oxyalkylation catalyst rather than the conventional potassium hydroxide or sodium hydroxide catalysts. Other, strongly basic cesium salts, for example cesium methoxide, or other basic, cesium containing compound, for example cesium oxide, cesium carbonate, cesium acetate and other cesium alkoxides such as the alkoxides of C 2 -C 8 lower alkanols may also be utilized. Preferably the catalyst contains, in addition to cesium hydroxide, no more than 50 mole percent of other alkali metal hydroxides and more preferrably, no more than 20 mole percent. Most preferably, pure or technical grade cesium hydroxide alone is utilized.
When the polyoxypropylene or higher alkylene oxide-derived hydrophobe is prepared first by oxyalkyklating a mono-, di-, or higher functional initiator such as methanol, butanol, ethylene glycol, propylene glycol, butylene glycol, glycerine, tetrakis (2-hydroxypropyl)-ethylenediamine or the like, potassium hydroxide may be used as the initial oxyalkylation catalyst provided that the hydrophobe is of modest molecular weight, i.e., equivalent weights of less than 2000, preferably less than 1500. However, in this case, the residual potassium hydroxide catalyst is preferably removed prior to additional oxypropylation to higher molecular weights, and, in any case, before oxyethylation. The mechanics of polyether preparation are otherwise conventional and well known to those skilled in the art. Examples of such preparation may be found, for example, in the treatise by Schick entitled Nonionic Surfactants, and in U.S. Pat. Nos. 2,674,619, 2,677,700, and 3,036,188 which are herein incorporated by reference.
The amount of cesium hydroxide catalyst utilized is the same as that utilized when sodium hydroxide or potassium hydroxide is the catalyst, on a mole-to-mole basis. Generally, from 0.005 percent to about 5 percent, preferably 0.005 percent to 2.0 percent, and most preferably 0.005 percent to 0.5 percent by weight of catalyst relative to the finished product is utilized. The catalyst composition during oxyethylation should be essentially cesium hydroxide. Up to 75 mole percent of potassium or sodium hydroxide may be tolerated in the cesium hydroxide catalyst, but generally less than 20 mole percent, and preferably less than 10 mole percent relative to total catalyst are preferred. Cesium alkoxides of C 1 -C 8 lower alkanols, particularly cesium methoxide, as well as other highly basic cesium salts may also be used if desired. Thus the catalyst may contain a basic cesium compound and conventional potassium or sodium hydroxide catalysts in mole ratios of greater than 1:3, preferably greater than 1:1, and more preferably greater than about 4:1 or 9:1.
The hydrophobe of the polyoxyalkylene block polyethers of the subject invention are derived from a higher alkylene oxide, or from tetrahydrofuran. By the term "higher alkylene oxide" is meant alkylene oxides having from 3 to about 18 carbon atoms in the alkylene moiety. While the hydrophobe is preferably a polyoxypropylene hydrophobe, other hydrophobes based on higher alkylene oxides such as 1,2-butylene oxide and 2,3-butylene oxide may also be used. Although not preferred, the hydrophobe also may be derived from C 8 to C 18 olefin oxides, or from the polymerization of tetrahydrofuran. The oxyalkylation of a suitable initiator with a higher alkylene oxide results in the synthesis of a polyoxy(higher alkylene) block.
The examples which follow serve to illustrate the process of the subject invention. All polyethers are prepared by conventional techniques with the exception of the particular catalyst utilized. The oxyalkylation is performed in a stainless steel high pressure stirred autoclave. The initial charge, consisting of initiator or intermediate base, and catalyst is vacuum stripped at a temperature of from about 90° C. to 125° C. and a pressure of c.a. 10 torr to remove water. The propylene oxide feed rates are adjusted so as to maintain the reactor pressure at 90 psig or below, including a 45 psig nitrogen pad.
COMPARATIVE EXAMPLE A
Unsaturation Formation During Ethylene Oxide Addition
A block polyether is prepared conventionally as described above. The initiator is tetrakis[2-hydroxypropyl]ethylenediamine which is oxypropylated at a temperature of 100° C. using conventional KOH catalysis at a catalyst concentration of 0.08 percent by weight relative to the final product (post oxyethylation) weight. Following oxypropylation, a portion of the oxypropylated intermediate base is treated with magnesium silicate to remove residual KOH catalyst and analyzed. The c.a. 3900 Dalton molecular weight product has an unsaturation, expressed as mg. of KOH per gram of polyether, of 0.008. The remainder of the intermediate base is reacted at a temperature of 160° C. with sufficient ethylene oxide to produce a polyoxypropylenepolyoxyethylene tetrol having a nominal molecular weight, based on ethylene oxide charged, of 39,500 Daltons. This product is treated with magnesium silicate to remove residual KOH catalyst and analyzed. The product has a measured unsaturation of 0.054 meq KOH/g. A 15 percent by weight aqueous solution has a viscosity at 50° C. of only 18.0 centistokes.
This example illustrates that unsaturation is formed during ethylene oxide addition as well as during propylene oxide addition, a phenomenon not previously considered of importance in block copolymer synthesis. It was expected that unsaturation produced during oxypropylation would be "diluted" during ethylene oxide addition. The finished product, which has a molecular weight approximately ten times higher than the polyoxypropylene polyether intermediate base, would therefore have an unsaturation one-tenth as great, or approximately 0.0008 meq KOH/g. However, instead of this very low, almost insignificant level of unsaturation, the finished product shows an unsaturation of 0.054 meq KOH/g, some seven times higher than the intermediate base, and sixty-seven times higher than expected! The elimination mechanism discussed previously cannot account for the large increase in unsaturation.
The molecular weight distribution of the polyether of Comparative Example A as shown by gel permeation chromatography is shown in FIG. 1 as "polyether A." As indicated, the molecular weight distribution is rather broad, with the major peak centered at a molecular weight of only 36,000 Daltons, considerably below the theoretical molecular weight of 39,500 Daltons. In addition, a large shoulder, representing about 15 percent by weight of the polyether, has a molecular weight of only 9700 Daltons.
EXAMPLE 1
The process of Comparative Example A is followed except that a 1:1 mixture of cesium hydroxide and potassium hydroxide is used throughout the oxyalkylation with both propylene oxide and ethylene oxide. The ethylene oxide addition temperature is 135° C. The hydrophobe has a nominal molecular weight of 3900 Daltons, while the product polyether molecular weight is 39,500 Daltons as in Example A. The product has an aqueous viscosity at 15 percent concentration of 177 centistokes at 50° C. The unsaturation, determined graphically by interpolation from known values, is 0.005 meq KOH/g. The molecular weight distribution, as determined by gel permeation chromatography, is shown in FIG. 1 as "polyether 1." The bulk of the product elutes as a narrow peak centered at 42,000 Daltons. This is a considerably narrower range than that achieved through conventional catalysis as indicated by the chromatograph of Comparative Example A. In addition, the cesium hydroxide catalyzed product has a higher overall molecular weight.
EXAMPLE 2
The process of Example 1 is followed, but cesium hydroxide alone is used for the oxyalkylation. The product gels at 15 percent aqueous concentration. A 12 percent by weight aqueous solution has a viscosity of 57.9 centistokes. The unsaturation is estimated graphically to be 0.004 meq KOH/g. The molecular weight distribution is shown in FIG. 1. A fairly narrow peak at 40,000 Daltons comprises the bulk of the polyether, with only a slight shoulder at 12,000 Daltons, indicating that the cesium hydroxide catalyzed product has both higher overall molecular weight and a narrower molecular weight distribution than conventionally catalyzed products.
EXAMPLE 3
The process of Example 1 is followed, but oxypropylation is stopped after 20 moles of propylene oxide are added. Following removal of residual KOH catalyst by means of magnesium silicate, the c.a. 1700 mw polyoxypropylated product is recatalyzed with an amount of cesium hydroxide chemically equivalent to the amount of KOH originally used. Sufficient additional propylene oxide is added to achieve a nominal hydrophobe molecular weight of 3900 Daltons, following which ethylene oxide is added to achieve a final polyether molecular weight of 39,500 Daltons, as before. The 50° C. aqueous viscosity at 15 percent by weight concentration is 109 centistokes. The product has an estimated unsaturation of 0.006 meq KOH/g determined graphically from the aqueous measured viscosity.
COMPARISON EXAMPLE B
A conventional triblock polyoxyalkylene polyether is prepared by oxypropylating propylene glycol in the presence of KOH as the catalyst until a molecular weight of 3000 Daltons is obtained, following which ethylene oxide is added until the polyoxyethylene-polyoxypropylene-polyoxyethylene polyether has a nominal theoretical molecular weight of 10,000 Daltons calculated from the measured hydroxyl number of 8.9 meq KOH/g. A 20 percent by weight aqueous solution of the solid product produces a gel.
EXAMPLE 4
A triblock polyoxyalkylene polyether is produced exactly as in Comparison Example B except that cesium hydroxide replaces potassium hydroxide as the catalyst on a mole-to-mole basis. The product has a hydroxyl number identical to that of the polyether of Comparison Example B, but an aqueous gel is produced at only 16 percent solids, an improvement of 20 percent. | Polyoxyalkylene block polyether polyols having enhanced physical properties are prepared by catalyzing the ethylene oxide addition with cesium hydroxide or mixtures of cesium hydroxide with other basic catalysts. These polyethers are especially useful in surface active applications. | 2 |
CROSS REFERENCE TO RELATED APPLICATIONS/INCORPORATION BY REFERENCE STATEMENT
[0001] The present application is a continuation of U.S. Ser. No. 12/879,598, filed Sep. 10, 2010; which is a continuation of U.S. Ser. No. 11/186,724, filed Jul. 21, 2005, now abandoned. The entire contents of each of the above-referenced patent applications are hereby expressly incorporated herein by reference.
FIELD OF THE INVENTION
[0002] This invention relates to alloys of titanium having at least 50% titanium and most specifically to an alloy of titanium particularly useful in the aerospace and defense industries known as 6/4 which is about 6% by weight aluminum and about 4% by weight vanadium with the balance titanium and trace materials as made by the Armstrong process.
BACKGROUND OF THE INVENTION
[0003] The ASTM B265 grade 5 chemical specifications for 6/4 require that vanadium is present in the amount of 4%±1% by weight and aluminum is present in the range of from about 5.5% to about 6.75% by weight. The alloy of the invention is produced by the Armstrong Process as previously disclosed in U.S. Pat. Nos. 5,779,761; 5,958,106 and 6,409,797, the entire disclosures of which are herein incorporated by reference. The aforementioned patents teach the Armstrong Process as it relates to the production of various materials including alloys. The Armstrong Process includes the subsurface reduction of halides by a molten metal alkali or alkaline earth element or alloy. The development of the Armstrong Process has occurred from 1994 through the present, particularly as it relates to the production of titanium and its alloys using titanium tetrachloride as a source of titanium and using sodium as the reducing agent. Although this invention is described particularly with respect to titanium tetrachloride, aluminum trichloride and vanadium tetrachloride and sodium as a reducing metal, it should be understood that various halides other than chlorine can be used and various reductants other than sodium can be used and the invention is broad enough to include those materials.
[0004] However, because the Armstrong Process over the past eleven years has been developed using molten sodium and chlorides, it is these materials which are referenced herein. During the production of titanium by the Armstrong Process, as disclosed in the previous patents, the steady state temperature of the reaction can be controlled by the amount of reductant metal and the amount of chloride being introduced. Although it is feasible to control the reaction temperature by varying the chloride concentration while keeping the amount of molten metal constant, the preferred method is to control the temperature of the reactant products by varying the amount of excess (over stoichiometric) reductant metal introduced into the reaction chamber. Preferably, the reaction is maintained at a steady state temperature of about 400° C. and at this temperature, as previously disclosed, the reaction can be maintained for very long periods of time without damage to the equipment while producing a relatively uniform product.
[0005] Heretofore, commercially pure (CP) titanium ASTM 8265 grades 1, 2, 3 and 4 have been produced in over two hundred runs using the Armstrong Process and although a wide variety of operating parameters have been tested, certain results are inherent in the process. The ASTM B 265 spec sheet follows:
[0000]
TABLE 1
Chemical Requirements
Composition %
Grade
Element
1
2
3
4
5
6
7
8
9
10
Nitrogen max
0.03
0.03
0.05
0.05
0.05
0.05
0.03
0.02
0.03
0.03
Carbon max
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.10
0.08
Hydrogen B max
0.015
0.015
0.015
0.015
0.015
0.020
0.015
0.015
0.015
0.015
Iron Max
0.20
0.30
0.30
0.50
0.40
0.50
0.30
0.25
0.20
0.30
Oxygen max
0.18
0.25
0.35
0.40
0.20
0.20
0.25
0.15
0.18
0.25
Aluminum
—
—
—
—
5.5 to
4.0 to
—
2.5 to
—
—
6.75
6.0
—
3.5
—
—
Vanadium
—
—
—
—
3.5 to
—
—
2.0 to
4.5
3.0
Tin
—
—
—
—
—
2.0 to
—
—
—
—
3.0
—
—
—
—
Palladium
—
—
—
—
—
—
0.12 to
—
0.12 to
—
0.25
0.25
Molybdenum
—
—
—
—
—
—
—
—
—
0.2 to 0.4
Zirconium
—
—
—
—
—
—
—
—
—
—
Nickel
—
—
—
—
—
—
—
—
—
0.6 to 0.9
Residuals C.D.E.
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
(each), max
Residuals C.D.E.
0.4
0.4
0.4
0.4
0.4
0.4
0.4
0.4
0.4
0.4
(total) max
Titanium F
remainder
remainder
remainder
remainder
remainder
remainder
remainder
remainder
remainder
remainder
A Analysis shall be completed for all elements listed in this Table for each grade. The analysis results for the elements not quantified in the Table need not be reported unless the concentration level is greater than 0.1% each or 0.4% total.
B Lower hydrogen may be obtained by negotiation with the manufacturer.
C Need not be reported.
D A residual is an element present in a metal or an alloy in small quantities inherent to the manufacturing process but not added intentionally.
E The purchaser may, in his written purchase order, request analysis for specific residual elements not listed in this specification. The maximum allowable concentration for residual elements shall be 0.1% each and 0.4% maximum total.
F The percentage of titanium is determined by difference.
[0006] Production of titanium powder by the Armstrong Process inherently produces powder in which the average diameter of individual particle is less than a micron. During distillation at 500 to 600° C., the particles agglomerate and have an average agglomerated particle diameter in the range of from about 3.3 to about 1.3 microns. Particle diameters are based on a calculated size of a sphere from a surface area, such as BET. For agglomerated particles, the calculated average diameters were based on surface are measurements in a range of from about 0.4 to about 1.0 m 2 per gram. In over two hundred runs, the titanium powder produced by the Armstrong Process always has a packing fraction in the range of from about 4% to about 11% which also may also be expressed as tap density. Tap density is a well known characteristic and is determined by introducing the powder into a graduated test tube and tapping the tube until the powder is fully settled. Thereafter, the weight of the powder is measured and the packing fraction or percent of theoretical density is calculated.
[0007] Moreover, during the production of CP titanium by the Armstrong Process, a certain amount of sodium has always been retained even after extensive distillation, including vacuum distillation, and this retained sodium has been present on average of about 500-700 ppm, and has rarely been below about 400 ppm. From a commercial point of view, significant effort is and has been expended in order to reduce the sodium content of CP titanium made by the Armstrong Process.
[0008] Prior to the Armstrong Process, CP titanium powder and titanium alloy powder traditionally have been made by two methods, hydride-dehydride and spheridization, resulting in powders having very different morphologies than the powder made by the Armstrong method. Hydride-dehydride powders are angular and flake-like, while spheridized powders are spheres.
[0009] Fines made during the Hunter process are available and these also have very different morphology than CP titanium produced by the Armstrong Process. SEMs of CP powder made by the hydride-dehydride process and the spheridization process and Hunter fines are illustrated in FIGS. 1 to 3 , respectively. The CP powder made by the Armstrong Process is not spherical nor is it angular and flake-like. Hunter fines have “large inclusions” which do not appear in the Armstrong powder, differentiating FIGS. 1-3 from Armstrong powder shown in FIGS. 4-9 . Moreover, Hunter fines have large concentrations of chlorine while Armstrong CP powder has low concentrations of chlorine; chlorine is an undesirable contaminant.
[0010] 6/4 powder is made by hydride-dehydride and spherization processes, but not by the Hunter process. A calcium reduction hydride-dehydride process used in Tula, Russia was identified by Moxson et al. in an article in The International Journal Of Powder Metallurgy, Vol. 34, No. 5, 1998. Moxson et al which also discloses SEMs of both CP and 6/4 in the Journal Of Metallurgy, May, 2000, both articles, the disclosures of which are incorporated by reference, taken together showing that 6/4 powder made by methods other than the Armstrong process result in powders that are very different from Armstrong 6/4 powder, both in size distribution and/or morphology and/or chemistry. In some cases, such as the calcium reduction process in Tula, Russia there are very significant differences in chemistry as well as the other differences previously mentioned. Both the hydride-dehydride and spheridization methods require Ti, Al and V to be mixed as liquids and thereafter formed into powder. Only the Armstrong Process produces alloy powder directly from gas mixtures of the alloy constituents.
[0011] Because 6/4 titanium is the most common titanium alloy used by the Department of Defense (DOD) as well as the aerospace industry and other significant industries, the production of 6/4 by the Armstrong Process is an important commercial goal.
SUMMARY OF THE INVENTION
[0012] Accordingly, a principal object of the present invention is to provide a titanium base alloy powder having lesser amounts of aluminum and vanadium with unique morphological and chemical properties.
[0013] Another object of the present invention to provide a titanium base alloy powder having about 6 percent by weight aluminum and about 4 percent by weight vanadium within current ASTM specifications.
[0014] Yet another object of the invention is to make a 6/4 alloy as set forth in which sodium is present in significantly smaller amounts than is present in CP titanium powder made by the Armstrong Process.
[0015] Still another object of the present invention is to provide a titanium base alloy powder having about 6% by weight aluminum and about 4% by weight vanadium with an alkali or alkaline earth metal being present in an amount less than about 200 ppm and the alloy powder being neither spherical nor angular or flake shaped.
[0016] A further object of the present invention is to provide a titanium base alloy powder having about 6% by weight aluminum and about 4% by weight vanadium with an alkali or alkaline earth metal being present in an amount less than about 200 ppm and having a tap density or packing fraction in the range of from about 4% to about 11%.
[0017] Yet another object of the present invention is to provide a titanium base alloy powder having about 6% by weight aluminum and about 4% by weight vanadium with an alkali or an alkaline earth metal being present in an amount less than about 200 ppm made by the subsurface reduction of chloride vapor with molten alkali metal or molten alkaline earth metal.
[0018] A final object of the present invention is to provide an agglomerated titanium base alloy powder having about 6% by weight aluminum and about 4% by weight vanadium with an alkali or alkaline earth metal being present in an amount less than about 100 ppm substantially as seen in the SEMs of FIGS. 10-12 .
[0019] The invention consists of certain novel features and a combination of parts hereinafter fully described, illustrated in the accompanying drawings, and particularly pointed out in the appended claims, it being understood that various changes in the details may be made without departing from the spirit, or sacrificing any of the advantages of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] For the purpose of facilitating an understanding of the invention, there is illustrated in the accompanying drawings a preferred embodiment thereof, from an inspection of which, when considered in connection with the following description, the invention, its construction and operation, and many of its advantages should be readily understood and appreciated.
[0021] FIG. 1 is a SEM of CP powder made by the hydride-dehydride method;
[0022] FIG. 2 is a SEM of CP powder made by the spheridization method;
[0023] FIG. 3 is a SEM of CP powder from the Hunter Process;
[0024] FIG. 4-6 are SEMs of Armstrong CP distilled, dried and passivated;
[0025] FIG. 7-9 are SEMs of Armstrong CP distilled, dried, passivated and held at 750° C. for 48 hours; and
[0026] FIG. 10-12 are SEMs of Armstrong 6/4 distilled, dried, passivated and held at 750° C. for 48 hours.
DETAILED DESCRIPTION OF THE INVENTION
[0027] As used herein, a “titanium base alloy” means any alloy having 50% or more by weight titanium. Although 6/4 is used as a specific example, other titanium base alloys are included in this invention. As seen from the previous discussion, Armstrong CP titanium powder is different from spheridized titanium powder and from hydride-dehydride titanium powder in both morphology and packing fraction or tap density. There are also differences in certain of the chemical constituents. For instance, Armstrong CP titanium powder has sodium present in the 400-700 ppm range while spheridized and hydride-dehydride powder should have none or only trace amounts. Armstrong CP titanium has little chloride concentration, on the order of <50 ppm, while Hunter fines have much larger concentrations of chlorides, on the order of 0.12-0.15 wt. %).
[0028] The equipment used to produce the 6/4 alloy is substantially as disclosed in the aforementioned patents disclosing the Armstrong Process with the exception that instead of only having a titanium tetrachloride boiler 22 as illustrated in those patents, there is also a vanadium tetrachloride boiler and an aluminum trichloride boiler which are connected to the reaction chamber by suitable valves. The piping acts as a manifold so that the gases are completely mixed as they enter the reaction chamber and are introduced subsurface to the flowing liquid sodium. It was determined during production of the 6/4 alloy that aluminum trichloride is corrosive and required special materials not required for handling either titanium tetrachloride or vanadium tetrachloride. Therefore, Hastelloy C-276 was used for the aluminum trichloride boiler and the piping to the reaction chamber.
[0029] During most of the runs the steady state temperature of the reactor was maintained at about 400° C. by the use of sufficient excess sodium. Other operating conditions for the production of the alloy were as follows:
[0030] A device similar to that described in the incorporated Armstrong patents was used except that a VCl 4 boiler and AlCl 3 boiler were provided and both gases were fed into the line feeding TiCl 4 into the liquid Na. The boiler pressures and system parameters are listed hereafter.
Experimental Procedure
[0031] TiCl 4 Boiler Pressure=500 kPa
[0032] VCl 4 Boiler Pressure=630 kPa
[0033] AlCl 3 Boiler Pressure=830 kPa
[0034] Inlet Na temperature=240° C.
[0035] Reactor Outlet Temperature=510 C
[0036] Na Flowrate=40 kg/min
[0037] TiCl 4 Flowrate=2.6 kg/min
[0038] For this specific experiment, a 7/32″ nozzle was used in the reactor to meter the mix of metal chloride vapors. A 0.040″ nozzle was used to meter the AlCl 3 and a 0.035″ nozzle was used to meter the VCl 4 into the TiCl 4 stream. The reactor was operated for approximately 250 seconds injecting approximately 11 kg of TiCl 4 . The salt and titanium alloy solids were captured on a wedge wire filter and free sodium metal was drained away. The product cake containing titanium alloy, sodium chloride and sodium was distilled at approximately 100 milli-torr at 550 to 575° C. vessel wall temperatures for 20 hours. Once all the sodium metal was removed via distillation, the trap was re-pressurized with argon gas and heated to 750° C. and held at temperature for 48 hours. The vessel containing the salt and titanium alloy cake was cooled and the cake was passivated with a 0.7 wt % oxygen/argon mixture. After passivation, the cake was washed with deionized water and subsequently dried in a vacuum oven at less than 100° C.
[0039] Table 2 below sets forth a chemical analysis of various runs for 6/4 alloy from an experimental loop running the Armstrong Process.
[0000]
TABLE 2
Ti 6/4 FROM EXPERIMENTAL LOOP
Run
Size
Oxygen
Sodium
Nitrogen
Hydrogen
Chloride
Vanadium
Aluminum
Carbon
Iron
N-269-
*
0.187
0.019
0.006
0.0029
0.001
5.58
5.58
0.019
0.014
N-269-
+
0.113
0.0015
0.008
0.003
0.001
5.33
5.38
0.03
0.021
N-269-
+
0.128
0.0006
0.005
0.0037
0.001
5.84
5.47
0.039
0.02
N-271-
+
0.124
0.002
0.001
0.0066
0.0016
4.87
6.95
0.033
0.037
N-276
+
0.111
0.0018
4.44
6.04
N-276
+
0.121
0.0018
0.005
0.0043
0.0005
4.12
6.35
0.012
0.016
N-276
+
0.131
0.0019
0.003
0.0057
0.0011
4.03
5.67
0.012
0.016
N-276
+
0.169
0.0026
4.1
6.02
N-276
+
0.128
0.0015
0.003
0.0042
0.0005
3.8
6.02
0.012
0.019
N-277
+
0.155
0.0018
0.003
0.0053
0.0006
3.45
5.73
0.014
0.015
N-277
+
0.135
0.0023
3.49
5.49
N-276
*
0.121
0.0041
0.005
0.0052
0.0005
4.31
6.53
0.02
0.015
N-276
*
0.134
0.0075
3.81
5.92
N-276
*
0.175
0.014
0.012
0.0066
0.0005
3.96
6.01
N-276
*
0.187
0.046
0.007
0.0081
0.0005
3.95
6.05
N-277
*
0.141
0.0022
0.004
0.0038
0.0026
3.65
5.42
Mean
0.14125
0.0069125
0.0051667
0.00495
0.00095
4.295625
5.914375
0.0212222
0.0192222
Stand dev.
0.0253811
0.0116064
0.0028868
0.0015952
0.000626
0.7343838
0.4335892
0.0102808
0.0071024
* = BULK
+ = SMALL
[0040] As seen from the above Table 2, the sodium levels for 6/4 are very low on the order of 69 ppm and for certain runs, sodium levels have been undetectable. This result was unexpected because over two hundred runs of CP titanium have been made using the Armstrong Process, and sodium has always been present in the range of from about 400-700 ppm. Therefore, the lack of sodium in the 6/4 alloy was not only unexpected but an important consideration since sodium may adversely affect the welds of CP titanium.
[0041] Other important aspects shown in Table 2 are the percentages of vanadium and aluminum in the 6/4 showing an average of about 5.91% aluminum and about 4.29% vanadium for all of the runs. The runs reported in Table 2 were made with an experimental loop and the valving and control systems for metering the appropriate amount of both vanadium and aluminum were rudimentary. Advanced valving systems have now been installed to control more closely the amount of vanadium and aluminum in the 6/4 produced from the Armstrong Process, although even with the rudimentary control system, the 6/4 alloy was within ASTM specifications. Also of significance is the low iron and chloride content of the 6/4 alloy.
[0042] An additional unexpected feature of the 6/4 alloy compared to the CP titanium is the surface area, as determined using BET Specific Surface Area analysis with krypton as the adsorbate. In general, the specific surface area of the 6/4 alloy is much larger than the CP titanium and this also was unexpected. Surface analysis of CP particles which were distilled overnight (about 8-12 hours) between 500-575° C. were 0.534 square meters/gram whereas 6/4 alloy measured 3.12 square meters/gram, indicating that the alloy is significantly smaller than the CP.
[0043] The SEMs show that the 6/4 powder is “frillier” than CP powder, see FIGS. 4-9 and 10 - 12 . As reported by Moxson et al., Innovations in Titanium Powder Processing in the Journal of Metallurgy May 2000, it is clear that by-product fines from the Kroll or Hunter Processes contain large amounts of undesirable chlorine which is not present in the CP titanium powder made by the Armstrong Process (see Table 1). Moreover, the morphology of the Hunter and Kroll fines, as previously discussed, is different from the CP powder made by the Armstrong Process. Neither the Kroll nor the Hunter process has been adapted to produce 6/4 alloy. Alloy powders have been produced by melting prealloyed stock and thereafter using either gas atomization or a hydride-dehydride process (MHR). The Moxson et al. article discloses 6/4 powder made in Tula, Russia and as seen from FIG. 2 in that article, particularly FIGS. 2 c and 2 d the powders made by Tula Hydride Reduction process are significantly different than those made by the Armstrong Process. Moreover, referring to the Moxson et al. article in the 1998 issue of the International Journal of Powder Metallurgy, Vol. 4, No. 5, pages 45-47, it is seen that the chemical analysis for the pre-alloy 6/4 powder produced by the metal-hydride reduction (MHD) process contains exceptional amounts of calcium and also is not within ASTM specifications for aluminum.
[0044] Because the 6/4 alloy made by the Armstrong Process is made without the presence of either calcium or magnesium, these metals should be present, if at all, only in trace amounts and certainly much less than 100 ppm. Sodium which would be expected to be present in significant quantities based on the operation of the Armstrong Process to produce CP titanium in fact is present only at minimum quantities in the 6/4 alloy. Specifically, sodium in the 6/4 alloy made by the Armstrong Process is almost always present less than 200 ppm and generally less than 100 ppm. In some instances, 6/4 alloy has been produced using the Armstrong Process in which sodium is undetectable so that this is a great and unexpected advantage of the 6/4 alloy vis a vis CP titanium made by the Armstrong Process.
[0045] Both the Armstrong CP titanium and 6/4 alloy have tap densities or packing fractions in the range of from about 4% to 11%. This tap density or packing fraction is unique and inherent in the Armstrong Process and, while not advantageous particularly with respect to powder metallurgical processing, distinguishes the CP powder and the 6/4 powder made by the Armstrong Process from all other known powders.
[0046] As is well known in the art, solid objects can be made by forming 6/4 or CP titanium into a near net shapes and thereafter sintering, see the Moxson et al. article and can also be formed by hot isostatic pressing, laser deposition, metal injecting molding, direct powder rolling or various other well known techniques. Therefore, the titanium alloy powder made by the Armstrong method may be formed into a sintered product or may be formed into a solid object by well known methods in the art and the subject invention is intended to cover all such products made from the powder of the subject invention.
[0047] While the invention has been particularly shown and described with reference to a preferred embodiment hereof, it will be understood by those skilled in the art that several changes in form and detail may be made without departing from the spirit and scope of the invention which includes titanium base alloys having lesser amounts of aluminum and vanadium and is specifically not limited to the specific alloys disclosed. | A titanium base alloy powder is formed by subsurface reduction of a chloride vapor with a molten alkali metal or molten alkaline earth metal to form reaction products comprising pre-alloy particles and a salt of the alkali metal or the alkaline earth metal. A majority of the pre-alloy particles have a composition of at least 50% by weight of titanium, about 5.38% to 6.95% by weight of aluminum, and about 3% to 5% by weight of vanadium. The pre-alloy particles are recovered from the reaction products to produce a titanium base alloy powder containing less than about 200 ppm alkali or alkaline earth metal. | 2 |
BACKGROUND OF THE INVENTION
When a cartridge is fired in a firearm the powder in the cartridge is ignited by the primer and as the powder burns it generates gases that propel the bullet out of the cartridge case and down the barrel of the firearm. Normally, most of these gases leave the bore of the barrel of the firearm after the bullet exits the bore since the rear of the barrel is sealed during the firing process by the cartridge case which expands outward under the pressure of the gases to seal the chamber area of the barrel.
With certain firearms a portion of the gases in the bore of the barrel are used to open the action of the firearm. In such cases there is usually a port or hole along the barrel that permits a portion of the gases to be directed outside of the bore of the barrel. These gases either impinge upon a part, usually called an operating rod, that serves to unlock the breech of the firearm or are fed via what is usually called a gas tube to what is called a bolt carrier where the gases exert a rearward force upon the bolt carrier that results in unlocking the bolt and causing it to move to its open rearward position. In the M-16 or M-15 family of firearms, the bolt carrier also has a part called the bolt carrier key for receiving the gases from the gas tube. In this latter type of operation this results in gases in and around the bolt carrier in the receiver that need to be dispersed.
In the well known M-16 or AR-15 family of firearms, two holes are provided in the bolt carrier that are designed to vent gases within the bolt carrier outward and away from the receiver area of the firearm. However, these holes in practice do not vent all of the gases outside of the receiver and in addition a certain amount of gases are dumped into the receiver of the firearm when the bolt carrier key with its gas hole moves rearward away from the rear portion of the gas tube when the bolt carrier is pushed to the rear under gas pressure. This gas tends to travel to the rear of the receiver along the paths created by the charging handle and its associated pathway in the receiver. Since the rear portion of the charging handle is located near the eyes of the shooter this has the undesirable and dangerous effect of diverting gases into shooter's eyes which can cause eye damage or at least interfere with the shooter's ability to see properly and hence shoot accurately.
As might be expected, this undesirable and potentially dangerous gas situation becomes even more severe with a firearm that is fired fully automatically. It has also been determined that the dangerous gas situation is severe in suppressed firearms.
In the past there have been various attempts to remedy or alleviate this undesirable and dangerous problem. These have included the use of silicone rubber seals and the addition of baffles. Unfortunately, gas and heat resulted in the eroding away of the silicone rubber seals and baffles have a tendency to fall off the receiver of the firearm.
This invention eliminates the undesirable and dangerous problem of gas near the eyes of the shooter. With this invention, the gas in the vicinity of the firearm charging handle is controlled and is diverted away from the eye region of the shooter. This is also accomplished without any modifications to the basic firearm by a simple substitution of a new charging handle that is fully compatible with the existing firearm receiver and other associated parts. With this new charging handle the gas is both diverted and the eyes of the shooter are also shielded. In addition, the new charging handle also has provisions for making it easier to be operated by the shooter.
SUMMARY OF THE INVENTION
This invention relates to firearm charging handles for loading a firearm with a cartridge and more particularly to firearm charging handles that protect the shooter and are easier to operate.
Accordingly, it is an object of the invention to provide a firearm charging handle that has increased safety for the shooter.
It is an object of the invention to provide a firearm charging handle that protects the eyes of the shooter.
It is an object of the invention to provide a firearm charging handle that controls gases that develop within the receiver of a firearm when it is fired.
It is an object of the invention to provide a firearm charging handle that is particularly useful with firearms that fire semi-automatically and or fully automatically.
It is an object of the invention to provide a firearm charging handle that is particularly useful with firearms that fire semi-automatically and or fully automatically such as the AR-15 or M-16 type firearms.
It is an object of the invention to provide a firearm charging handle that is particularly useful with firearms that fire semi-automatically and or fully automatically that are sound suppressed.
It is an object of the invention to provide a firearm charging handle that avoids sighting problems related to powder gases in the shooter's eyes.
It is an object of the invention to provide a firearm charging handle that diverts powder gases away from the shooter's eyes.
It is an object of the invention to provide a firearm charging handle that shields the eyes of the shooter from undesired and dangerous powder gases.
It is an object of the invention to provide a firearm charging handle that is easier to operate than current charging handles.
It is an object of the invention to provide a firearm charging handle that is easily operated by the shooter while wearing gloves.
It is an object of the invention to provide a firearm charging handle that has an improved latch.
It is an object of the invention to provide a firearm charging handle that has an improved latch that is more comfortable for the shooter to operate than the current latch.
It is an object of the invention to provide a firearm charging handle that is readily interchangeable with existing AR-15 or M-16 type firearms family charging handles.
It is an object of the invention to provide a firearm charging handle that requires no modification of the firearm for its use.
These and other objects will be apparent from the charging handle invention for a firearm having a receiver, a bolt reciprocating within the receiver and a gas tube for directing powder gases to cause operation of the bolt within the receiver in which the charging handle includes a generally elongated member having a forward end portion and a rearward end portion, with the rearward portion having at least a portion thereof extending outside of the receiver and being sized, shaped and adapted to be grasped by a hand of a shooter using the firearm and means for protecting the shooter from powder gases that may be around the charging handle when the firearm is fired.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be hereinafter more fully described with reference to the accompanying drawings in which:
FIG. 1 is a side elevational view of a prior art firearm with a prior art charging handle illustrating the gas problem with a prior art charging handle and previous attempts to alleviate this problem;
FIG. 2 is a side elevational view of a prior art charging handle such as set forth in FIG. 1;
FIG. 3 is a top plan view of the prior art charging handle illustrated in FIG. 2;
FIG. 4 is a side elevational view of the charging handle of the invention illustrating how powder gases are blocked to protect the eyes of the shooter;
FIG. 5 is a top plan view of the charging handle of the invention set forth in FIG. 4 illustrating how powder gases are diverted to protect the eyes of the shooter;
FIG. 6 is an enlarged sectional view of the charging handle of the invention set forth in FIG. 4 taken on the line 6 — 6 thereof;
FIG. 7 is an enlarged sectional view of the charging handle of the invention set forth in FIG. 4 taken on the line 7 — 7 thereof;
FIG. 8 is an enlarged sectional view of the charging handle of the invention set forth in FIG. 5 taken on the line 8 — 8 thereof;
FIG. 9 is an enlarged end view of the charging handle of the invention set forth in FIG. 8 taken in the direction of the line 9 — 9 thereof;
FIG. 10 is an enlarged bottom view of a portion of the charging handle of the invention set forth in FIG. 5;
FIG. 11 is a top plan view of a prior art latch and associated handle portion for a charging handle;
FIG. 12 is a top plan view of an improved latch for a charging handle that replaces the latch set forth in FIG. 11; and
FIG. 13 is a rear elevational view of the latch illustrated in FIG. 12 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 illustrates a side elevational view of the receiver area of an M-16 type firearm that is designated generally by the number 10 with portions broken away. The firearm 10 has the well known upper and lower receiver 12 and 14 , bolt 16 , bolt carrier 18 with its bolt carrier key 20 , charging handle 22 and a gas tube 24 . The firearm 10 illustrated in FIG. 1 is shown after a cartridge 26 has been fired and its bullet has just left the barrel 28 . At this time, part of the powder gases generated from the fired cartridge 26 have passed through the gas tube 24 and into the bolt carrier key 20 with the resulting rearward movement of the bolt carrier 18 and bolt carrier key 20 .
The bulk of the released powder gases are expelled out of the bolt carrier 18 , through the ports 30 and out of the ejection port 32 of the firearm 10 . However, powder gases are also released in the area designated by the letter A that is inside the receiver 12 of the firearm 10 . These powder gases remain in the receiver 12 and this creates a positive gas pressure area. This positive gas pressure area and the rearward movement of the bolt 16 and the bolt carrier 18 when the firearm 10 is fired forces powder gases along with dirt and other debris inside the receiver 12 to the rear of the receiver 12 and out of the cracks 34 between the charging handle 22 and the upper receiver 12 and into the face and eyes of the person firing the firearm 10 as illustrated by the letter B.
Such gases, dirt and other debris not only interfere with the accurate shooting of the firearm 10 , but also can be dangerous to the shooter and particularly the eyes of the shooter. It should be understood that any reference to powder gas or gases in connection with a charging handle is meant to include not only gases resulting from the combustion of the powder or propellant from cartridges but also may include oil, partially burnt powder, unburnt powder, mud, dust, and other similar matter collected in the firearm 10 in a hostile environment that can be contained in or carried by powder gases.
This undesirable problem of having powder gases introduced into the face of the shooter has been recognized in the past and attempts have been made to glue or bond silicone rubber to the charging handle 22 near its rear end portion 36 as illustrated by the numbers 38 and 40 in FIG. 1 . Unfortunately, these rubber seals 38 and 40 tend not to be effective since they are readily eroded away by the heat and force of the powder gases. Another attempt to alleviate this powder gas problem has been through the addition of metal shields such as the shields 44 and 46 attached to the rear end portion 36 of the charging handle 22 as illustrated in FIG. 1 . These shields 44 and 46 are attached to the charging handle 22 by screws (not shown). Unfortunately, these shields are not that effective and they tend to come loose in use. In addition, these shields 44 and 46 tend to interfere with the normal use of the charging handle 22 . Fortunately, this invention does not have these problems associated with the silicone rubber seals 38 and 40 or the add on shields 44 and 46 .
FIGS. 2 and 3 set forth the side and top views of the prior art charging handle designated generally by the number 22 for the M-16 type firearm 10 illustrated in FIG. 1 . As illustrated in FIGS. 2 and 3, the charging handle 22 has an elongated body portion 51 with basically smooth and unbroken sides 52 and 54 and basically a smooth and unbroken top surface 56 that terminate in an enlarged handle portion 58 on the rear end portion 36 of the charging handle 22 . Since both of the sides 52 and 54 and the top surface 56 of the charging handle 22 are smooth and unbroken they serve as excellent surfaces for powder gases to travel along and in addition there is really nothing on the handle portion 58 to deflect powder gases to any large extent. It should be noted that the charging handle 22 has a deflecting surface 59 that is shaped like a portion of the circumference of a circle that is located in the upper surface 56 of the handle portion 58 . This deflecting surface 59 that is shaped to conform to the circumference of a circle in the prior art charging handle 22 for the M-16 family of weapons is part of the circumference of a circle with a radius R that is equal to 0.875 of an inch.
FIGS. 4 and 5 set forth side and top views of the charging handle of the invention that is designated generally by the number 60 . This charging handle 60 has an elongated body portion 62 that is identical to the body portion 51 for the prior art charging handle 22 . This body portion has smooth and unbroken sides 64 and 66 and a smooth and unbroken top surface 68 that are the same as the corresponding surfaces 52 , 54 , and 56 of the body portion 51 .
However, the charging handle invention 60 set forth in FIGS. 4 and 5 has important differences from the prior art charging handle 22 set forth in FIGS. 1, 2 , and 3 . Specifically, the charging handle 60 has an enlarged and differently configured rear end portion 70 . In this connection, the rear end portion 70 has a generally T-shaped grasping handle portion 72 with an upward extending shield portion 74 that has a forward sloping gas deflecting surface 76 and right and left downward extending shield portions 78 a and 78 b that have respective gas deflecting surfaces 80 a and 80 b . These downward extending shield portions 78 a and 78 b are mirror images of each other and are located on the handle portion 72 in position to be located on each side of the adjacent portion of the lower receiver 14 of the firearm 10 when the charging handle 60 is installed in the firearm 10 and is in its normal forward firing position. The downward extending shield portions 78 a and 78 b must also be sized, shaped and located on the handle portion 72 to clear the butt stock of the firearm 10 when the charging handle 60 is pulled rearward.
As indicated in FIG. 5, the charging handle 60 has a grasping portion 72 with a gas deflecting surface 76 that is different from the surface 59 set forth in FIG. 3 . In this connection, when viewed from the top as illustrated in FIG. 5 the gas deflecting surface 76 is shaped to conform to the circumference of a circle having a radius Ri and as indicated this Ri is related to the previous prior art R set forth in FIG.3 by the relationship:
1.25R≦Ri≦2.0R
Where:
R Is the radius of the circle formed by the deflecting surface 59 on the charging handle 22 for the AR-15 or M-16 type family of firearms.
This relationship has been determined to be important for the proper deflection of powder gases etc. In the preferred embodiment, Ri is equal to 2.0R or 1.75 inches.
Also as indicated in FIG. 5, the charging handle 60 has a rectangular shaped gas groove 84 in its upper surface 68 located adjacent to the grasping portion 72 . FIGS. 6, 7 , and 8 are sectional views taken on the lines 6 — 6 , 7 — 7 , and 8 — 8 on the views in FIGS. 4 and 5 that illustrate in greater detail the important features of the charging handle invention 60 . As indicated by the sectional view in FIG. 6, the body portion 62 has a generally horseshoe shaped cross section 86 with an open channel 88 in the center of its underside 90 . This same cross section is essentially unchanged for the entire length of the body portion 62 . As also illustrated in FIG. 6, the forward portion 92 of the charging handle 60 has a downward depending portion 94 and a round aperture 96 . This body portion 62 is identical to that of the standard prior art body portion 51 of the standard charging handle 22 .
The sectional views in FIGS. 7, 8 and 9 along with the bottom view in FIG. 10 of the rear end portion 70 of the charging handle 60 illustrate important features of the charging handle invention 60 that are different from the conventional charging handle 22 . As illustrated in FIG. 10, the rear end portion 70 of the charging handle 60 has, in addition to the upper gas groove 84 , a lower gas groove 98 that is in fluid communication with the open channel 88 in the underside of the body portion 62 so that any gas in this open channel 88 can readily pass into the lower gas groove 98 and leave the charging handle 60 and the firearm 10 .
As previously indicated in FIG. 5, the upper gas groove 84 is rectangular shaped. Also, as illustrated in FIG. 7, the bottom surface 100 of this gas groove 84 makes an angle D with the upper surface 102 of the T-shaped grasping portion 72 . In the preferred embodiment, this angle D is between five degrees and 10 degrees. In addition, this bottom surface 100 of the groove 84 slopes downward toward the right side 66 of the charging handle 60 . Consequently, this groove 84 allows any gases that may move rearward along or adjacent the upper surface 102 of the charging handle 62 to pass into the groove 84 and be diverted by the groove 84 to the right side 66 of the charging handle 62 and away from the firearm 10 .
In addition to the gas grooves 84 and 98 that direct powder gases to the right side of and away from the firearm 10 , the charging handle 60 also has the rear portion 70 with the generally T-shaped grasping portion 72 with the upward extending shield portion 74 with the gas deflecting surface 76 and the downward shield portion 78 b with its gas deflecting surface 80 b that are also set forth in FIG. 8 as well as the previously described FIGS. 4 and 5. These deflecting surfaces 76 and 80 b and also 80 a cooperate with the grooves 84 and 98 to deflect additional gun gases that are not diverted by the grooves 84 and 98 in order to keep powder gases away from the vicinity of the eyes of the shooter.
As illustrated in FIG. 10, the wall 104 of the gas groove 98 is shaped to form part of the circumference of a circle with a radius Rq that should be between 0.6 of an inch and 1.0 inch and 0.65 of an inch in the preferred embodiment. Since the wall 104 is formed in the shape of part of the circumference of a circle, it tends to divert gun gases in the lower gas groove 98 not only outward but also forward toward the muzzle or front end portion of the firearm 10 .
As best illustrated in FIGS. 8 and 9 and also FIG. 5, the rear end portion 70 of the charging handle 60 has an upward projecting gas deflecting protrusion 101 that is located in the center of the of the rear end portion 70 adjacent to the shield portion 74 . As illustrated in FIG. 9, the protrusion 101 , when viewed from the grasping handle portion 72 end of the charging handle 60 , has the shape of a portion of the circumference of a circle with a radius Rs equal to substantially one half of an inch and its upper surface 103 is located substantially a distance equal to one half of an inch above the the adjacent upper surface 105 of the rear end portion 70 . This protrusion 101 has curved surfaces 107 and 109 with radii Rv substantially equal to one half of an inch that merge with the upper surface 105 . This protrusion 101 has a forward inclined gas deflecting surface 111 that is located adjacent to the previously described gas deflecting surface 76 . As best illustrated in FIG. 8, the gas deflecting surface is also inclined at the same angle E as the gas deflecting surface 76 which is between 70 degrees and 80 degrees and 80 degrees in the preferred embodiment.
FIG. 11 illustrates a top view of a conventional charging handle latch that is designated generally by the number 108 . This latch 108 is illustrated as it is attached by a pin 109 to the handle portion 58 of the conventional charging handle 22 . This latch 108 locks the charging handle 22 in place in its forward position within the receiver of the firearm 10 . The current prior art latch 108 is difficult to use and FIG. 12 illustrates the top view of an improved latch designated generally by the number 110 that overcomes the deficiencies of the previous latch 108 . This new latch 110 has an important feature that is not present on the previous latch 108 . This feature is the addition of an enlarged finger pad area 112 illustrated in FIGS. 12 and 13 that provides an enlarged surface area 114 that is to be contacted by the finger of the person that is using the firearm 10 .
This enlarged surface area 114 allows the user of the firearm to easily exert a larger force to operate the latch 110 than is possible with a conventional prior art latch 108 that does not have this pad portion with its enlarged surface area 114 . The latch with its enlarged surface area 114 is also easier to operate with a hand that has a glove on it. This enlarged surface area 114 is also illustrated in the end view set forth in FIG. 12 . This new latch 110 has a conventional hole 116 that is located and sized to receive a conventional roll pin. In order to reduce the weight of the latch 110 a generally rectangular hole 118 is located in its central portion.
The charging handle 60 is made in the following manner. The charging handle 60 can be made in the same manner as the current charging handle 22 from suitable strength aluminum that can be forged or investment cast. Basically, the configuration is identical to the prior art charging handle 22 except that the rear portion 70 is larger and has a different shape as previous indicated. Any necessary forming or shaping is accomplished using conventional cutting, machining and shaping techniques that are well known in the art. The latch 110 is formed in a similar manner, however, in the preferred embodiment it is made by stamping from a suitable grade steel known in the art. The parts are protected by conventional anodizing for aluminum and by Parkerizing or a manganese phosphate coating in the case of the steel latch 110 . The latch 110 is assembled on the charging handle 60 in a conventional manner using the conventional roll pin 118 and a conventional latch spring (not shown).
In order to install the charging handle 60 , the prior art charging handle 22 is removed from the firearm 10 in a conventional manner, by pushing the firearm's take down pin to the left, opening the firearm 10 and removing the bolt carrier and bolt first and then the charging handle 22 from the firearm 10 . The new charging handle 60 is then inserted into the firearm 10 in place of the prior art charging handle 22 and the firearm 10 is reassembled.
The new improved charging handle 60 is used in exactly the same manner as the prior art charging handle 22 except that it is easier to grasp and use by the shooter. In addition, the new charging handle 60 prevents or greatly reduces powder gases that are directed toward the eyes and face of the shooter.
Although the invention has been described in considerable detail with reference to a certain preferred embodiment, it will be understood that variations or modifications may be made within the spirit and scope of the invention as defined in the appended claims. | A charging handle for a firearm having a receiver, a bolt and bolt carrier reciprocating within the receiver and a gas tube for directing powder gases to cause operation of the bolt carrier and bolt within the receiver. The charging handle is a generally elongated member having a forward end portion and a rearward end portion with the rearward portion having a portion that extends outside of the receiver that is sized, shaped and adapted to be grasped by a hand of a shooter using the firearm. The charging handle has grooves and gas deflecting surfaces for diverting and deflecting powder gases to protect the shooter from powder gases that may develop around the charging handle when the firearm is fired. | 5 |
GOVERNMENT RIGHTS
This invention was made with Government support under FAR 52.227-12 awarded by Comanche EMD contract. The Government has certain rights in this invention.
BACKGROUND OF THE INVENTION
The present invention generally relates to the production of articles of manufacture in a computer simulation or in the real world, and more particularly, to a method for accurately evaluating pattern compliance for a simulated or manufactured article.
American, Canadian, German, and International Organization for Standardization (ISO) standards define methods for specifying multiple levels of pattern and feature related tolerances often referred to as composite positional tolerances. Composite positional tolerances include a pattern locating tolerance and a feature relating tolerance. A pattern locating tolerance is a tolerance that relates a collection of manufactured features on an object relative individually to the specified datums of the designed pattern. A feature relating tolerance can include a tolerance relating to the size of a feature, the positions of a set of features relative to each other, and the rotation of a pattern of features relative to a specified origin.
Another specification may include maximum material condition (MMC) and least material condition (LMC). MMC may be defined as the condition in which a feature of size contains the maximum amount of material within the stated limits of size, for example, minimum hole diameter or maximum shaft diameter. LMC may be defined as the condition in which a feature of size contains the least amount of material within the stated limits of size, for example, maximum hole diameter, or minimum shaft diameter. An allowable tolerance may be specified as the combination of the pattern-locating and feature related tolerances and a material condition.
Presently, the manufacturing industry does not have an efficient or effective way of determining whether or not the feature relating requirements are achieved. Inspection of manufactured articles and analyzing the resulting data are not currently evaluated in an automated and correct manner to determine whether or not combined manufactured features such as hole size and location are acceptable to the applied feature relating tolerances. For example, evaluating manufactured hole size, form, orientation, and location are all completed separately, and confidence in the accuracy of each evaluation is low.
Referring to FIG. 1 , one method for documenting inspection data consists of paper gaging, where information is recorded on paper. Measurements are taken, and hole positions 92 are plotted on a grid 94 at an enlarged scale using a true position 96 as the origin. Concentric circles 90 representing tolerance zone diameters are then overlain to determine compliance with the pattern locating tolerance. This method does not consider variation in feature size easily, and does nothing to examine compliance with the feature relating tolerance.
As can be seen, there is a need for accurately determining inspection data. Also, there is a need for determining inspection data in a timely manner, with perhaps, using only a single iteration. Moreover, there is a need for quickly analyzing inspection data in a step of the manufacturing process so that the results of the analysis can be used in subsequent processes.
Variation effects within a pattern of features may also be determined when performing a variation analysis of a design prior to manufacturing that design. The variation analysis software performs hundreds or thousands of simulated build cycles, and in each cycle, varies all of the parameters randomly. Assembly variation analysis that utilizes feature patterns, such as holes, for assembly is currently reliant on approximations and iterations for the assembly of parts. Such a process may introduce error, is inefficient, and requires advanced software skills for completion.
In addition to the need for assessing produced parts, there is a need to accurately determine the variation effects on patterns of features during variation analysis.
SUMMARY OF THE INVENTION
The present invention provides a machine-readable medium for programming a computer to determine feature relating tolerance consumed for a plurality of manufactured features on an object, the medium including processor executable instructions comprising determining a true position for each of the plurality of manufactured features, determining a location for each of the plurality of manufactured features, organizing each of the true positions into a single association, organizing the location of each of the plurality of manufactured features relative to the single association, determining a circle that intersects or contains each location, determining the diameter of the circle, and comparing the diameter of the circle with the size of the feature relating tolerance to determine acceptability of the pattern.
In one aspect of the present invention, a machine-readable medium programs a computer to determine feature relating tolerance consumed for a plurality of manufactured holes on an object, the medium including processor executable instructions comprising, determining a true position for each of the plurality of manufactured holes, determining a center for each of the plurality of manufactured holes, superimposing each of the true positions to form one true position, determining the centers of each of the plurality of manufactured holes relative to the one true position, determining a circle that intersects or contains each of the centers of the circles, determining the diameter of the circle, and determining feature relating tolerance consumed from said diameter.
In another aspect of the present invention, a machine-readable medium programs a computer to determine feature relating tolerance consumed for a plurality of manufactured features on an object where at least one additional feature is added to a pattern of features, the medium including processor executable instructions comprising, determining a true position for each of the plurality of manufactured features, determining a location for each of the plurality of manufactured features, organizing each of the true positions into a single association, organizing the location of each of the plurality of manufactured features relative to the single association, determining a first circle that intersects or contains each location, determining the location of the additional feature, determining if the location of the additional feature is contained within the first circle, determining a second circle that intersects or contains the plurality of manufactured features and the additional feature, if the additional feature is not contained with the first circle, determining the diameter of the second circle, and comparing the diameter of the second circle with the feature relating tolerance to determine acceptability of the pattern.
Another aspect of the present invention provides machine-readable medium for programming a computer to determine feature relating tolerance consumed for a plurality of manufactured features on an object, the medium including processor executable instructions comprising, determining a true position for each of the plurality of manufactured features, determining a center for each of the plurality of manufactured features, organizing each of the true positions into a one true position, organizing the center of each of the plurality of manufactured features relative to the one true position, determining a departure circle about each of the centers, and determining a circle that is tangent to or contains each of the departure circles.
Another aspect of the present invention provides a machine-readable medium for programming a computer to determine whether a pattern of features violates a pattern locating tolerance for a plurality of manufactured features on an object, the medium including processor executable instructions comprising, determining a true position for each of the plurality of manufactured features, determining a center for each of the plurality of manufactured features, organizing each of the true positions into a one true position, organizing the center of each of the plurality of manufactured features relative to the one true position, determining a departure circle about each of the centers, and determining where the departure circles lie relative to a pattern locating tolerance circle.
Another aspect of the present invention provides a system in a manufacturing site, the system comprising a computer and a coordinate measuring machine adapted to determine whether a pattern of manufactured features violate a pattern locating tolerance, and adapted to determine feature relating tolerance consumed for the pattern of features, the system adapted to perform the steps of determining a true position for each of the plurality of manufactured features, determining a center for each of the plurality of manufactured features, organizing each of the true positions into a one true position, organizing the center of each of the plurality of manufactured features relative to the one true position, determining a departure circle about each of the centers, determining if any of the departure circles lies outside a pattern locating tolerance circle to determine if the pattern locating tolerance is violated, determining a circle that is tangent to or contains each of the departure circles, and comparing a diameter of said circle to said feature relating tolerance to determine acceptability of the pattern.
Another aspect of the present invention provides a method for determining feature relating tolerance consumed for a plurality of manufactured features on an object comprising determining a true position for each of the plurality of manufactured features, determining a location for each of the plurality of manufactured features, organizing each of the true positions into a single association, organizing the location of each of the plurality of manufactured features relative to the single association, determining a circle that intersects or contains each location, determining the diameter of the circle, and comparing the diameter of the circle with the feature relating tolerance to determine the acceptability of the pattern.
In a further aspect of the present invention provides a method to determine used tolerances for a plurality of manufactured features on an object comprising determining a true position for each of the plurality of manufactured features, determining a center for each of the plurality of manufactured features, organizing each of the true positions into a one true position, organizing the center of each of the plurality of manufactured features relative to the one true position, determining a departure circle about each of the centers, determining a circle that contains each of the departure circles, and comparing the circle to the magnitude of the feature relating tolerances.
These and other features, aspects and advantages of the present invention will become better understood with reference to the following drawings, description and claims.
What is needed is a method to evaluate manufactured objects for pattern compliance and compliance with allowable tolerance in a timely and accurate manner. This method may be hand implemented as well as being implemented as a computer program retained on a machine-readable medium.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram illustrating a prior art paper gaging technique for documenting inspection data;
FIG. 2 is a diagram illustrating a designed rectangular plate having three holes, according to an embodiment of the present invention;
FIG. 3 is a diagram illustrating a manufactured rectangular plate for the designed rectangular plate in FIG. 2 , according to an embodiment of the present invention;
FIG. 4 is a diagram illustrating the centers of manufactured holes relative to a one true position, according to an embodiment of the present invention;
FIG. 5 is a diagram illustrating a pattern locating tolerance zone about the one true position illustrated in FIG. 4 , according to an embodiment of the present invention;
FIG. 6A is a diagram illustrating an embodiment of the rectangular plate in FIG. 3 , with an additional manufactured hole, according to an embodiment of the present invention;
FIG. 6B is a diagram illustrating an embodiment of the rectangular plate in FIG. 3 , with an additional manufactured hole, according to an embodiment of the present invention;
FIG. 7 is the center of the additional manufactured hole in FIG. 6A , shown relative to the one true position in FIG. 5 , according to an embodiment of the present invention;
FIG. 8 is the center of the additional manufactured hole in FIG. 6B , shown relative to the one true position in FIG. 5 , according to an embodiment of the present invention;
FIG. 9 is a diagram illustrating a pattern related circle that includes all the centers of the manufactured holes of FIG. 6B , according to an embodiment of the present invention;
FIG. 10 is a diagram illustrating hole centers relative to a one true position, according to an embodiment of the present invention;
FIG. 11 is a diagram illustrating the departure circles around the hole centers illustrated in FIG. 10 , according to an embodiment of the present invention;
FIG. 12 is a diagram illustrating a pattern locating tolerance used for the pattern in FIG. 11 ;
FIG. 13 is a diagram illustrating centers of four external features relative to a one true position;
FIG. 14 is a flowchart illustrating a method for determining feature relating tolerance consumed for a plurality of manufactured features on an object; and
FIG. 15 is a flowchart illustrating a method for determining consumed feature-relating tolerance for a plurality of manufactured features on an object.
DETAILED DESCRIPTION OF THE INVENTION
The following detailed description is of the best currently contemplated modes of carrying out the invention. The description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles of the invention, since the scope of the invention is best defined by the appended claims. References to manufactured features may equally refer to features generated in a computer simulation or features produced in fabrication processes.
The present invention provides a machine readable medium, method and system for determining the size and location of manufactured features on an object, determining the translation of a pattern of features, and determining tolerance consumed. Such method may be, but is not limited to, hand-implemented or implemented by a computer program. By determining tolerance consumed for features such as holes during or shortly after a manufacturing process, mating parts can be correctly designed and efficient assembly processes chosen. The present invention may be implemented at or in close proximity to a manufacturing site where the manufactured article is produced.
The present invention differs from the prior art in that the present invention provides a method for accurately determining inspection information. Also, the present invention provides a method for determining inspection information in a timely manner using only a single iteration. Moreover, the present invention provides a method for quickly analyzing inspection data in a step of the manufacturing process so that the results of the analysis can be used in subsequent processes.
In an embodiment, FIG. 2 is a diagram illustrating the designed features for an object such as a part. The designed part may be a rectangular plate 10 having features including three spaced-apart circular holes 12 , 14 , 18 . The manufactured holes may have a cross-sectional shape, including, but not limited to, circular, oval and quadrilateral. Each of the designed circular holes 12 , 14 , 18 has a center, referred to as the true center 19 , 20 , 24 , respectively, and a designed size, referred to as a true size. The designed size may be gauged using the diameter of the circle as well as the area of the circle. Each hole 12 , 14 , 18 may have a designed position on the rectangular plate referred to as a true position. The true centers 19 , 20 , 24 may be used as the true position 119 , 120 , 124 for each hole 12 , 14 , 18 , respectively. One of the true centers, for example, the true center 24 for the bottom left circle 18 may be used as the origin of a Cartesian coordinate system. A computer aided drafting (CAD) system may be used to render the diagram. The information of the circular holes 12 , 14 , and 18 may be represented as digital data and stored on a machine-readable medium including a hard drive and an optical disk, as well as being processed on a computer.
FIG. 3 is a diagram illustrating a manufactured rectangular plate 28 , created from the design illustrated in FIG. 2 . The manufactured holes 30 , 32 , and 36 correspond to designed holes 12 , 14 and 18 . Manufactured rectangular plate 28 may also represent a simulated manufactured plate, and manufactured holes 30 , 32 , and 36 may represent simulated manufactured holes. The simulated holes may be generated to provide a variation analysis model of a rectangular plate. Each manufactured hole 30 , 32 , 36 has deviated from the true size as well as the true position. A true size deviation may comprise a hole larger than designed, or a hole smaller than designed. Each hole may have a positional error relative to its true position. The positional error may be determined by the distance between center 38 , 40 , 44 of each manufactured hole 30 , 34 , 36 and their true positions 119 , 120 , 124 , respectively. The deviations may extend along the depth of each hole. Data regarding the dimensions and position of the manufactured rectangular plate 28 may be acquired by many methods known in the art, including, but not limited to, examining the rectangular plate 28 with a coordinate measuring machine.
FIG. 4 is a diagram illustrating the centers 38 , 40 , 44 of each manufactured hole relative to a one true position 46 . The one true position 46 represents the true positions of each manufactured holes 30 , 32 , 36 as a single point. The one true position 46 may be a superimposition of true positions 119 , 120 , 124 . The centers 38 , 40 , 44 of each manufactured hole are drawn relative to the one true position 46 as they would be drawn relative to their true positions 119 , 120 , 124 ( FIG. 3 ), respectively. The one true position 46 may be represented as the arbitrarily-positioned origin of a coordinate system, including an x, y coordinate system and in this coordinate system, the centers 38 , 40 , 44 of each manufactured hole are drawn with respect to the one true position 46 .
FIG. 5 is a diagram illustrating a circle 50 that represents the pattern locating tolerance zone (PLTZ) about the one true position 46 . A PLTZ is a tolerance zone that may be specified in the design data. The PLTZ specifies the positional tolerance for features in a group. The diameter D 1 of the circle 50 represents the PLTZ. A feature relating circle 52 may be drawn that intersects or includes each of the centers 38 , 40 , 44 . The feature relating circle 52 may represent the magnitude of the feature relating tolerances. The feature relating circle 52 provides a range of how the existing holes 30 , 32 , 36 ( FIG. 3 ) deviate from the one true position 46 , and thus, feature relating circle 52 provides an accurate indicator of the deviations of the manufactured holes 30 , 32 , 36 from the designed pattern. The diameter of the feature relating circle 52 indicates the maximum deviation of the manufactured holes 30 , 32 , 36 ( FIG. 3 ) and the amount of tolerances consumed. The region 56 outside of feature relating circle 52 would indicate a positional error relative to the pattern of features that is greater than any of the positional errors of manufactured holes 30 , 32 , 36 . The region 57 inside of feature relating circle 52 would indicate a positional error relative to the pattern of features that is smaller than the combined positional errors of manufactured holes 30 , 32 , 36 .
FIG. 6A is a diagram illustrating an embodiment of a rectangular plate 28 in FIG. 3 , with an additional manufactured hole 58 . In an embodiment, FIG. 7 is a diagram illustrating the center 60 of a fourth manufactured hole 58 ( FIG. 6A ) shown relative to the one true position 46 of FIG. 5 . The one true position 46 in FIG. 7 includes the true position 74 ( FIG. 6A ) of manufactured hole 58 . In this embodiment, the center 60 of manufactured hole 58 lies within the feature relating circle 52 , and thus manufactured hole 58 does not have a relative positional error greater than the deviation of manufactured holes 30 , 32 , 36 . Feature relating circle 52 remains a valid indicator of the range of the relative positional errors of all manufactured holes, 30 , 32 , 36 , 58 on the rectangular plate 28 .
FIG. 6B is a diagram illustrating an embodiment of the rectangular plate 28 in FIG. 3 , with an additional manufactured hole 70 . In another embodiment, FIG. 8 is a diagram illustrating a manufactured center 62 of the fourth manufactured hole 70 from FIG. 6B shown relative to the one true position 46 . The one true position 46 includes the true position 75 of manufactured hole 70 . In this embodiment, the center 62 of manufactured hole 70 lies outside of feature relating circle 52 , and thus manufactured hole 70 has a positional error that is greater than the deviation of manufactured holes 30 , 32 , 36 . Feature relating circle 52 is no longer a valid indicator of the range of the relative positional errors of all manufactured holes, 30 , 32 , 36 , 70 on the rectangular plate 28 . Thus, a new feature relating circle must be drawn that includes all of the centers.
FIG. 9 is a diagram illustrating a feature relating circle 76 that includes all the centers 38 , 40 , 44 and 62 of the manufactured holes 30 , 32 , 36 and 70 of FIG. 6B , respectively. The feature relating circle 76 may be derived by including manufactured center 72 , of manufactured hole 70 which was not included in feature relating circle 52 of FIG. 8 . Feature relating circle 76 includes manufactured centers 38 , 40 and 44 as well as manufactured center 62 . Feature relating circle 76 may be used as a gauge to determine the relative positional errors of manufactured holes 30 , 32 , 36 , 70 for the rectangular plate 28 in FIG. 6B .
In an embodiment, the used or consumed tolerance for any object having a pattern of features may be determined. FIG. 10 is a diagram illustrating manufactured centers 102 , 104 and 106 relative to a one true position 100 for an object, such as a rectangular plate having internal features such as holes. FIG. 11 is a diagram illustrating the size departure 112 , 114 and 116 as departure circles for each of hole centers 102 , 104 and 106 , respectively. The departure for an internal feature such as a hole may be the difference in diameter from the minimum hole diameter allowable for a feature in a pattern. This difference could be positive or negative. A positive difference in diameter is considered to be a positive diameter of the departure circle. A negative difference in diameter means that the feature relating circle should pass to the outside of that departure circle. The center for the departure circle is the still the manufactured center of the feature relative to a one true position. The departure for an external feature such as a pin may be the difference in diameter from the maximum pin diameter. A positive difference in diameter of an external feature means that the feature relating circle should pass to the outside of that departure circle.
FIG. 12 is a diagram illustrating the PLTZ 121 and used tolerance for the object in FIG. 11 . A PLTZ 121 may be represented by circle and is centered about the one true position 100 . The PLTZ 121 is not violated if a portion of each of the departure circles 112 , 114 , and 116 lies within the PLTZ circle 121 . The departure circle 112 , 114 and 116 for each hole center 102 , 104 and 106 may be drawn relative to the one true position 100 .
Still referring to FIG. 12 , the used tolerance of the holes corresponding to hole centers 102 , 104 and 106 may be derived by a used feature relating circle 122 that is tangent to the near side of each departure circle 112 , 114 and 116 . Typically, when circle 122 is drawn to the near side of each departure circle 112 , 114 and 116 , each departure circle 112 , 114 and 116 lies outside of circle 122 . The diameter D 3 of consumed tolerance circle 122 may be compared with the diameter D 4 of an allowable tolerance circle 160 that represents allowable feature relating tolerance. If diameter D 3 is greater than diameter D 4 then the pattern of internal features having centers 102 , 104 and 106 and size departures exceeds the allowable tolerances.
FIG. 13 is a diagram illustrating centers 132 , 134 , 136 , 138 of four external features relative to a one true position 130 . External features may include, but are not limited to, pins. Departure circles 142 , 144 , 146 148 are drawn about the centers 132 , 134 , 136 , 138 of each external feature, respectively. Similar to the method described in FIG. 12 , a PLTZ may be represented by circle 164 and may be centered about the one true position 130 . The PLTZ is not violated if each of the departure circles 142 , 144 , 146 148 lies entirely within the PLTZ circle 164 .
Still referring to FIG. 13 , a used tolerance circle 150 may be drawn that is the smallest circle that contains all of the departure circles 142 , 144 , 146 148 . Typically, the used tolerance circle 150 may be tangent to the outside of some of the departure circles, for example, departure circles 142 , 144 , and 146 . The diameter D 2 of the used tolerance circle 150 may be compared to with the diameter D 5 of an allowable tolerance circle 162 . If the diameter D 2 of the used tolerance circle 150 is smaller than the diameter D 5 of the allowable tolerance circle 162 , then the pattern of external features does not exceed the allowable tolerance. The diameter D 2 of used tolerance circle 150 may be compared with the diameter D 5 of an allowable tolerance circle 162 to determine the remaining allowable tolerance.
FIG. 14 is a flowchart illustrating an embodiment of the method illustrated in FIGS. 2–5 , for determining feature relating tolerance consumed for a plurality of manufactured features on an object. One step for determining remaining pattern related tolerance for a plurality of manufactured features on an object may comprise determining 168 a true position for each of the plurality of manufactured features. Another step for determining remaining pattern related tolerance for a plurality of manufactured features on an object may comprise determining 170 a location for each of the plurality of manufactured features. Another step may comprise organizing 172 each of the true positions into a single association. Another step may comprise organizing 174 the location of each of the plurality of manufactured features relative to the single association. Another step may comprise determining 176 a circle that intersects or contains each location. Another step may comprise determining 178 the diameter of the circle. Another step may comprise comparing 180 the diameter of the circle with the pattern related tolerance to determine the acceptability of the pattern.
FIG. 15 is a flowchart illustrating an embodiment of the method illustrated in FIGS. 10–13 , for determining consumed tolerances for a plurality of manufactured features on an object. One step for determining used tolerances for a plurality of manufactured features on an object may comprise determining 182 a true position for each of the plurality of manufactured features. Another step for determining used tolerances for a plurality of manufactured features on an object may comprise determining 184 a center for each of the plurality of manufactured features. Another step may comprise organizing 186 each of the true positions into a one true position. Another step may comprise organizing 188 the center of each of the plurality of manufactured features relative to the one true position. Another step may comprise determining 190 a departure circle about each of the centers. Another step may comprise determining 192 a circle that is tangent to or contains each of the departure circles. Another step may comprise comparing 194 the circle to the tolerances.
It should be understood, of course, that the foregoing relates to preferred embodiments of the invention and that modifications may be made without departing from the spirit and scope of the invention as set forth in the following claims. | A machine readable medium and a method are disclosed that determine whether a pattern of manufactured or simulated features violates a feature relating tolerance and determines acceptability of the pattern. Allowable tolerance may include feature relating tolerances and material conditions. Manufactured centers are drawn relative to a one true position. A circle drawn through or outside the manufactured centers is used to determine if there is feature relating tolerance violation. Material condition may also be used. | 6 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a national stage application under 35 U.S.C. §371 of international application PCT/EP00/03659 filed on Apr. 22, 2000, the international application not being published in English. This application also claims priority under 35 U.S.C. §119 to DE 199 19 769.5 filed on Apr. 30, 1999.
BACKGROUND OF THE INVENTION
This invention relates to the use of antimicrobial agents in nanoscale form for the production of body deodorants.
Body deodorants, also known simply as deodorants, are formulations which counteract, mask or eliminate body odors. Body odors are formed by the action of skin bacteria on apocrine perspiration which results in the formation of unpleasant-smelling degradation products. Accordingly, deodorants contain active principles which act as antibacterial agents, enzyme inhibitors, odor absorbers or odor maskers.
Nanoscale materials are materials whose particle diameter in the direction of the largest dimension of the particles is less than 1000 nm (nanometers). In the present specification, the term “nanoparticulate” is used synonymously with the term “nanoscale”. Nanoscale active principles are described in the literature in particular as agents for achieving a controlled release of the active principle over a prolonged period. For example, WO 98/14174 describes nanoparticles for parenteral therapeutic use which consist of a pharmacologically active substance encapsulated in a shell of a biodegradable polymer. The document in question mentions inter alia antibacterial agents, such as chloramphenicol and vanomycin, and antimicrobial agents, such as penicillins and cephalosporins, as examples of pharmacologically active substances. Antimicrobial products containing nanoscale Schiff—s bases of aromatic aldehydes are known from DE 4402103 which describes the use of these products for the lasting antimicrobial finishing of textiles. Patent application CA 2,111,523 describes disinfectants which, besides other constituents, also contain surface-modified nanoparticulate antimicrobial agents. A disinfecting cleaner formulation is mentioned as an example. Patent application CA 2,111,522 describes compositions with a long-lasting germicidal effect which contain surface-modified nanoparticulate antimicrobial agents. Disinfectants for surface treatment which form permanent antimicrobial films on the treated surface are mentioned as applications of these compositions. However, there is nothing in the prior art to suggest that nanoparticulate antimicrobial agents can be used with advantage as active principles in body deodorants. Although it is known to the expert that antimicrobial agents are used, for example, both in surface disinfection and in body deodorants, the expert also knows that the form of application and the requirements in regard to strength of effect, action spectrum and the formulation of the active principles are so different in the various fields of application that the knowledge acquired in one field of application cannot obviously be applied to another field of application.
Because of their physiochemical properties and their own odors, the active principles used in body deodorants are often attended in practice by the problem that they only be incorporated in deodorant formulations with difficulty or in inadequate concentrations so that the formulations obtained show unsatisfactory antimicrobial activity. In addition, there is a demand among consumers for body deodorants which work with reduced concentrations of the active principle without any loss of deodorizing effect and hence offer physiological, economic and/or ecological advantages.
Accordingly, one problem addressed by the present invention was to enable body deodorants to be produced using antimicrobial agents which, due for example to their poor solubility or their strong odor, can only be conventionally incorporated in body deodorants with difficulty or in inadequate concentrations.
Another problem addressed by the invention was to provide body deodorants with sufficient antimicrobial activity for practical application and, at the same time, a reduced content of antimicrobial agents.
The problems stated above have been solved by the use of the antimicrobial agents in the form of nanoparticles with a particle diameter of 5 to 500 nm and preferably 10 to 150 nm for the production of body deodorants.
SUMMARY OF THE INVENTION
In a first embodiment, therefore, the present invention relates to the use of nanoscale antimicrobial agents with a particle diameter of 5 to 500 nm and preferably 10 to 150 nm for the production of body deodorants, more especially deodorizing aerosols, pump sprays, roll-ons and sticks. The use of the nanoscale antimicrobial agents is particularly suitable for the production of products which are required to show only bacteriostatic activity and not bactericidal activity.
It has surprisingly been found that the following advantages, for example, are achieved in this way:
a) The incorporation of antimicrobial agents in deodorant formulations is improved to the extent that lipophilic active principles can be incorporated more easily in aqueous formulations while hydrophilic active principles can be incorporated more easily in nonaqueous or low-water formulations.
b) the effectiveness of the active principles from the formulations is increased. This means that, for the same quantity by weight, the nanoparticulate active principle has a stronger antimicrobial effect than the same active principle in a larger particle size corresponding to the prior art.
c) In the case of active principles with a strong odor of their own, the odor can be weakened or even suppressed by surface modification of the nanoscale particles.
DETAILED DESCRIPTION OF THE INVENTION
Antibacterial agents with substantially selective activity against bacteria involved in the formation of odor-generating substances in bodily perspiration are particularly suitable for the use according to the invention. Where antimicrobial agents are used, it is important to ensure that the population of the bacteria concerned is merely controlled to prevent excessive growth (bacteriostatic effect) and not to destroy the bacteria completely (which would correspond to bactericidal activity).
Any substances active against gram-positive bacteria are particularly suitable as antimicrobial agents according to the invention. Substances active against Corynebacterium xerosis are particularly preferred. The active substances according to the invention include, for example,
4-hydroxybenzoic acid, its salts with alkali or alkaline earth metals or its esters with linear or branched C 1-10 alcohols,
N-(4-chlorophenyl)-N′-(3,4-dichlorophenyl)-urea,
2,4,4′-trichloro-2′-hydroxy diphenyl ether (triclosan),
4-chloro-3,5-dimethyl phenol,
2,2′-methylene-bis-(6-bromo-4-chlorophenol),
3-methyl-4-(1-methylethyl)-phenol,
2-benzyl-4-chlorophenol,
3-(4-chloropenoxy)-propane-1,2-diol,
3-iodo-2-propinyl butyl carbamate,
chlorohexidine,
3,4,4′-trichlorocarbanilide (TTC),
1-hydroxy-4-methyl-6-(2,4,4-trimethylpentyl )-2-(1H)-pyridinone, ethanolamine salt (1:1) (Octopirox)
antimicrobial perfumes such as, for example, thymol or menthol,
glycerol monolaurate (GML),
diglycerol monocaprate (DMC),
zinc salts such as, for example, zinc glycinate, zinc lactate or zinc phenol sulfonate,
phytosphingosines,
dodecane-1,2-diol,
undecylenic acid, its salts with alkali or alkaline earth metals or its esters with linear or branched C 1-10 alcohols,
salicylic acid-N-alkyl amides where the alkyl groups contain 1 to 22 carbon atoms and may be linear or branched and mixtures thereof.
Particularly preferred antimicrobial agents according to the invention are salicylic acid-N-octyl amide and/or salicylic acid-N-decyl amide, 2,4,4′-trichloro-2′-hydroxydiphenyl ether and antimicrobially active perfumes.
The nanoscale active principles consist of a discrete phase of the active principle with preferably at least one surface modifier adsorbed onto its surface. Particularly suitable surface modifiers are emulsifiers and/or protective colloids. The coating of the particles with emulsifiers and/or protective colloids prevents subsequent agglomeration of the particles.
Suitable emulsifiers are, for example, nonionic surfactants from at least one of the following groups:
(1) products of the addition of 2 to 30 moles of ethylene oxide and/or 0 to 5 moles of propylene oxide onto linear C 8-22 fatty alcohols, C 12-22 fatty acids and alkyl phenols containing 8 to 15 carbon atoms in the alkyl group;
(2) C 12/18 fatty acid monoesters and diesters of addition products of 1 to 30 moles of ethylene oxide onto glycerol;
(3) glycerol monoesters and diesters and sorbitan monoesters and diesters of saturated and unsaturated fatty acids containing 6 to 22 carbon atoms and ethylene oxide adducts thereof;
(4) alkyl mono- and oligoglycosides containing 8 to 22 carbon atoms in the alkyl group and ethoxylated analogs thereof;
(5) products of the addition of 15 to 60 moles of ethylene oxide onto castor oil and/or hydrogenated castor oil;
(6) polyol esters and, in particular, polyglycerol esters such as, for example, polyglycerol polyricinoleate, polyglycerol poly-12-hydroxy stearate or polyglycerol dimerate. Mixtures of compounds from several of these classes are also suitable;
(7) products of the addition of 2 to 15 moles of ethylene oxide onto castor oil and/or hydrogenated castor oil;
(8) partial esters based on linear, branched, unsaturated or saturated C 6/22 fatty acids, ricinoleic acid and 12-hydroxystearic acid and glycerol, polyglycerol, pentaerythritol, dipentaerythritol, sugar alcohols (for example sorbitol), sucrose, alkyl glucosides (for example methyl glucoside, butyl glucoside, lauryl glucoside) and polyglucosides (for example cellulose);
(9) mono-, di and trialkyl phosphates and mono-, di- and/or tri-PEG-alkyl phosphates and salts thereof;
(10) wool wax alcohols;
(11) polysiloxanelpolyalkyl polyether copolymers and corresponding derivatives;
(12) mixed esters of pentaerythritol, fatty acids, citric acid and fatty alcohol according to DE-PS 11 65 574 and/or mixed esters of fatty acids containing 6 to 22 carbon atoms, methyl glucose and polyols, preferably glycerol or polyglycerol, and
(13) polyalkylene glycols.
The addition products of ethylene oxide and/or propylene oxide onto fatty alcohols, fatty acids, alkylphenols, glycerol monoesters and diesters and sorbitan monoesters and diesters of fatty acids or with castor oil are known commercially available products. They are homolog mixtures of which the average degree of alkoxylation corresponds to the ratio between the quantities of ethylene oxide and/or propylene oxide and substrate with which the addition reaction is carried out. C 12/18 fatty acid monoesters and diesters of addition products of ethylene oxide onto glycerol are known as refatting agents for cosmetic formulations from DE-PS 20 24 051.
C 8/18 alkyl mono- and oligoglycosides, their production and their use are known from the prior-art literature. They are produced in particular by reacting glucose or oligosaccharides with primary alcohols containing 8 to 18 carbon atoms. So far as the glycoside component is concerned, both monoglycosides where a cyclic sugar unit is attached to the fatty alcohol by a glycoside bond and oligomeric glycosides with a degree of oligomerization of preferably up to about 8 are suitable. The degree of oligomerization is a statistical mean value on which a homolog distribution typical of such technical products is based.
Typical examples of anionic emulsifiers are soaps, alkyl benzene-sulfonates, alkanesulfonates, olefin sulfonates, alkylether sulfonates, glycerol ether sulfonates, α-methyl ester sulfonates, sulfofatty acids, alkyl sulfates, fatty alcohol ether sulfates, glycerol ether sulfates, hydroxy mixed ether sulfates, monoglyceride (ether) sulfates, fatty acid amide (ether) sulfates, mono- and dialkyl sulfosuccinates, mono- and dialkyl sulfosuc cinamates, sulfotriglycerides, amide soaps, ether carboxylic acids and salts thereof, fatty acid isethionates, fatty acid sarcosinates, fatty acid taurides, N-acylamino acids such as, for example, acyl lactylates, acyl tartrates, acyl glutamates and acyl aspartates, alkyl oligoglucoside sulfates, protein fatty acid condensates (particularly wheat-based vegetable products) and alkyl-(ether) phosphates. If the anionic surfactants contain polyglycol ether chains, they may have a conventional homolog distribution although they preferably have a narrow-range homolog distribution.
Other suitable emulsifiers are zwitterionic surfactants. Zwitterionic surfactants are surface-active compounds which contain at least one quaternary ammonium group and at least one carboxylate and one sulfonate group in the molecule. Particularly suitable zwitterionic surfactants are the so-called betaines, such as the N-alkyl-N,N-dimethyl ammonium glycinates, for example cocoalkyl dimethyl ammonium glycinate, N-acylaminopropyl-N,N-dimethyl ammonium glycinates, for example cocoacylaminopropyl dimethyl ammonium glycinate, and 2-alkyl-3-carboxymethyl-3-hydroxyethyl imidazolines containing 8 to 18 carbon atoms in the alkyl or acyl group and cocoacylaminoethyl hydroxyethyl carboxymethyl glycinate. The fatty acid amide derivative known under the CTFA name of Cocamidopropyl Betaine is particularly preferred. Ampholytic surfactants are also suitable emulsifiers. Ampholytic surfactants are surface-active compounds which, in addition to a C 8/18 alkyl or acyl group, contain at least one free amino group and at least one —COOH— or —SO 3 H— group in the molecule and which are capable of forming inner salts. Examples of suitable ampholytic surfactants are N-alkyl glycines, N-alkyl propionic acids, N-alkylaminobutyric acids, N-alkyliminodipropionic acids, N-hydroxyethyl-N-alkylamidopropyl glycines, N-alkyl taurines, N-alkyl sarcosines, 2-alkylaminopropionic acids and alkylaminoacetic acids containing around 8 to 18 carbon atoms in the alkyl group. Particularly preferred ampholytic surfactants are N-cocoalkylaminopropionate, cocoacylaminoethyl aminopropionate and C 12/18 acyl sarcosine. According to the invention, other suitable emulsifiers besides ampholytic surfactants are quaternary emulsifiers, those of the esterquat type, preferably methylquaternized difatty acid triethanolamine ester salts, being particularly preferred. Typical examples of anionic emulsifiers are alkyl sulfates, alkyl ether sulfates and monoglyceride (ether) sulfates.
In general, the active principles and the emulsifiers are used in a ratio by weight of 1:100 to 100:1, preferably 1:25 to 25:1 and more preferably 1:10 to 10:1. Emulsifiers capable of forming microemulsions are particularly preferred.
Suitable protective colloids are, for example, gelatine, casein, gum arabic, lysalbinic acid, starch, carboxymethyl cellulose or modified carboxymethyl cellulose and polymers such as, for example, polyvinyl alcohols, polyvinyl pyrrolidones, polyalkylene glycols and polyacrylates.
Accordingly, the present invention also relates to the use according to the invention of nanoscale antimicrobial agents where the nanoparticles are coated with one or more emulsifiers and/or protective colloids.
The nanoparticles according to the invention can be produced, for example, by
(a) introducing active principles into a liquid phase in which they are insoluble,
(b) heating the resulting mixture to beyond the melting point of the active principles,
(c) adding an effective quantity of at least one emulsifier to the resulting oil phase and finally
(d) cooling the emulsion to below the melting point of the active principles.
Accordingly, the present invention also relates to the use according to the invention of nanoscale antimicrobial agents produced by this process.
Another process for the production of nanoparticles by rapid expansion of supercritical solutions (RESS) is known from the article by S. Chihlar, M. Türk and K. Schaber in Proceedings World Congress on Particle Technology 3 , Brighton , 1998. To prevent the nanoparticles from re-agglomerating, it is advisable to dissolve the starting materials in the presence of suitable protective colloids or emulsifiers and/or to expand the critical solutions into aqueous and/or alcoholic solutions of the protective colloids or emulsifiers or into cosmetic oils which may in turn contain redissolved emulsifiers and/or protective colloids.
Another suitable process for the production of nanoscale particles is the evaporation technique. Here, the starting materials are first dissolved in a suitable organic solvent (for example alkanes, vegetable oils, ethers, esters, ketones, acetals and the like). The resulting solutions are then introduced into water or another non-solvent, generally in the presence of a surface-active compound dissolved therein, in such a way that the nanoparticles are precipitated by the homogenization of the two immiscible solvents, the organic solvent preferably evaporating. O/w emulsions or o/w microemulsions may be used instead of an aqueous solution. The emulsifiers and protective colloids mentioned at the beginning may be used as the surface-active compounds. Another method for the production of nanoparticles is the so-called GAS process (gas anti-solvent recrystallization). This process uses a highly compressed gas or supercritical fluid (for example carbon dioxide) as non-solvent for the crystallization of dissolved substances. The compressed gas phase is introduced into the primary solution of the starting materials and absorbed therein so that there is an increase in the liquid volume and a reduction in solubility and fine particles are precipitated. The PCA process (precipitation with a compressed fluid anti-solvent) is equally suitable. In this process, the primary solution of the starting materials is introduced into a supercritical fluid which results in the formation of very fine droplets in which diffusion processes take place so that very fine particles are precipitated. In the PGSS process (particles from gas saturated solutions), the starting materials are melted by the introduction of gas under pressure (for example carbon dioxide or propane). Temperature and pressure reach near- or super-critical conditions. The gas phase dissolves in the solid and lowers the melting temperature, the viscosity and the surface tension. On expansion through a nozzle, very fine particles are formed as a result of cooling effects.
The above-mentioned production processes for the nanoparticles according to the invention are merely examples and are not intended to limit the invention in any way.
The body deodorants obtainable using the nanoscale antimicrobial agents in accordance with the invention may also contain, for example, fatty acids in the form of their alkali metal soaps, polyols, lower alcohols, enzyme inhibitors, odor absorbers, odor maskers, water, complexing agents, antioxidants, preservatives, perfumes, colorants, opacifiers, pearlizing pigments, fine-particle silica, consistency factors, gel formers, waxes, fatty alcohols, emulsifiers, thickeners and other suitable formulation bases as further auxiliaries and additives.
Fatty acids in the context of the invention are C 16-22 carboxylic acids such as, for example, palmitic acid, stearic acid and behenic acid or technical mixtures consisting predominantly of such fatty acids, for example hydrogenated palm oil fatty acid or hydrogenated tallow fatty acid.
Polyols in the context of the invention are those containing 3 to 6 carbon atoms and 2 to 6 hydroxyl groups such as, for example, ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, glycerol, erythritol, pentaerythritol, trimethylol propane, sorbitol, anhydrosorbitol, cyclohexane triol or inositol.
The preparations may contain ethanol or isopropanol, for example, as lower alcohols.
Suitable enzyme inhibitors are, for example, esterase inhibitors. Esterase inhibitors are preferably trialkyl citrates, such as trimethyl citrate, tripropyl citrate, triisopropyl citrate, tributyl citrate and, in particular, triethyl citrate (Hydagen® CAT, Henkel KGaA, Düsseldorf, FRG). Esterase inhibitors inhibit enzyme activity and thus reduce odor formation. Other esterase inhibitors are sterol sulfates or phosphates such as, for example, lanosterol, cholesterol, campesterol, stigmasterol and sitosterol sulfate or phosphate, dicarboxylic acids and esters thereof, for example glutaric acid, glutaric acid monoethyl ester, glutaric acid diethyl ester, adipic acid, adipic acid monoethyl ester, adipic acid diethyl ester, malonic acid and malonic acid diethyl ester, hydroxycarboxylic acids and esters thereof, for example citric acid, malic acid, tartaric acid or tartaric acid diethyl ester, and zinc glycinate.
Suitable odor absorbers are substances which are capable of absorbing and largely retaining the odor-forming compounds. They reduce the partial pressure of the individual components and thus also reduce the rate at which they spread. An important requirement in this regard is that perfumes must remain unimpaired. Odor absorbers are not active against bacteria. They contain, for example, a complex zinc salt of ricinoleic acid or special perfumes of largely neutral odor known to the expert as “fixateurs” such as, for example, extracts of ladanum or styrax or certain abietic acid derivatives as their principal component. Odor maskers are perfumes or perfume oils which, besides their odor-masking function, impart their particular perfume note to the deodorants. Suitable perfume oils are, for example, mixtures of natural and synthetic fragrances. Natural fragrances include the extracts of blossoms, stems and leaves, fruits, fruit peel, roots, woods, herbs and grasses, needles and branches, resins and balsams. Animal raw materials, for example civet and beaver, may also be used. Typical synthetic perfume compounds are products of the ester, ether, aldehyde, ketone, alcohol and hydrocarbon type. Examples of perfume compounds of the ester type are benzyl acetate, p-tert butyl cyclohexylacetate, linalyl acetate, phenyl ethyl acetate, linalyl, benzoate, benzyl formate, allyl cyclohexyl propionate, styrallyl propionate and benzyl salicylate. Ethers include, for example, benzyl ethyl ether while aldehydes include, for example, the linear alkanals containing 8 to 18 carbon atoms, citral, citronellal, citronellyloxyacetaldehyde, cyclamen aldehyde, hydroxy-citronellal, lilial and bourgeonal. Examples of suitable ketones are the ionones and methyl cedryl ketone. Suitable alcohols are anethol, citronellol, eugenol, isoeugenol, geraniol, linalool, phenylethyl alcohol and terpineol. The hydrocarbons mainly include the terpenes and balsams. However, it is preferred to use mixtures of different perfume compounds which, together, produce an agreeable fragrance. Other suitable perfume oils are essential oils of relatively low volatility which are mostly used as aroma components. Examples are sage oil, camomile oil, clove oil, melissa oil, mint oil, cinnamon leaf oil, lime-blossom oil, juniper berry oil, vetiver oil, olibanum oil, galbanum oil, ladanum oil and lavendin oil. The following are preferably used either individually or in the form of mixtures: bergamot oil, dihydromyrcenol, lilial, lyral, citronellol, phenylethyl alcohol, α-hexylcinnamaldehyde, geraniol, benzyl acetone, cyclamen aldehyde, linalool, Boisambrene Forte, Ambroxan, indole, hedione, sandelice, citrus oil, mandarin oil, orange oil, allylamyl glycolate, cyclovertal, lavendin oil, clary oil, β-damascone, geranium oil bourbon, cyclohexyl salicylate, Vertofix Coeur, Iso-E-Super, Fixolide NP, evernyl, iraldein gamma, phenylacetic acid, geranyl acetate, benzyl acetate, rose oxide, romillat, irotyl and floramat.
In order to be able to apply the active principles to the skin in a measurable, economic, convenient and cosmetically attractive manner, they have to be incorporated in suitable formulation bases. The most important of these are alcoholic and aqueous/alcoholic solutions, emulsions, gels, sticks—for example glycolic soap sticks—oils, wax/fat compounds and powders. Stabilizers, consistency factors and foam inhibitors, for example, may be used as additional auxiliaries.
Suitable supply forms for deodorants are aerosols, pump sprays, roll-ons, sticks and gels and also creams and powders.
The quantity in which the nanoscale compounds are used is selected so that the concentration of the antimicrobial agents present in the nanoparticles is normally between 0.01 and 5% by weight and preferably between 0.1 and 2% by weight, based on the preparations.
To produce the body deodorants according to the invention, the nanoscale antimicrobial agents are mixed with the other formulation ingredients in known manner.
The present invention also relates to body deodorants containing antimicrobial agents which are characterized in that the antimicrobial agent is incorporated in the form of nanoparticles with a particle diameter of 5 to 500 nm and preferably 10 to 150 nm.
Other embodiments and/or further developments are covered by the subsidiary claims.
EXAMPLES
The following Examples are intended to illustrate the invention.
Example 1
Prepararation of Sanoscale Nalicylic Acid-N-octyl Amide
0.5 g of salicylic acid-N-octyl amide (Mp. ca. 45° C.) were dissolved in 100 g of deionized water and the mixture was heated to around 50° C., resulting in the formation of a two-phase mixture of water and amide phase. The amide phase was emulsified by addition of 8.9 g of alkyl ether sulfate (Texapon® N 70, Henkel KGaA, Düsseldorf) to form a clear mixture. The gradual passing of the oil phase into the transparent water/amide/emulsifier mixture may be taken as an indication of the formation of a microemulsion. The microemulsion was cooled to ambient temperature with continued stirring and was then concentrated by evaporation to dryness in a rotary evaporator, 9.4 g of the salicylic acid-N-octyl amide encapsulated in the ether sulfate matrix being obtained in nanoparticulate form. The nanoparticles could be reprocessed with ten times the quantity of water to form a stable and transparent dispersion. In light scattering, the particles showed a maximum with numerical weighting at a particle size of 120 nm.
Example 2
Preparation of a Nanoscale Aqueous Salicylic Acid-N-octyl Amide Dispersion
1.0 g of salicylic acid-N-octyl amide (Mp. ca. 45° C.) were emulsified with 30 g of deionized water, 30 g of Polydiol 400 (PEG-8) and 2 g of polyoxyethylene glycerol fatty acid ester (Tagat S) and slowly heated to 52° C. 30 g of fatty acid amidoalkyl betaine (Tego Betain BL 215) were then added, a clear stable dispersion being formed. The mixture was then allowed to cool to room temperature. 93 g of a transparent dispersion were obtained. In light scattering, the particles showed a maximum with numeral weighting at a particle size of 15 nm.
Example 3
Formulation Example for a deodorizing pump spray formulation:
Ingredient
Content (% by weight)
Hydrogenated castor oil + 40 moles EO
2
(Eumulgin HRE, Henkel KGaA)
Aqueous dispersion of nanoscale salicylic
10
acid-N-octyl amide from Example 2
Perfume oil
0.3
Glycerol
7.7
Water
80 | A deodorant composition and method of making and using a deodorant composition are provided. The deodorant composition contains nanoscale antimicrobial particles where the nanoscale antimicrobial particles contain one or more antimicrobial agents and have a particle diameter in the range of from 5 nanometers to 500 nanometers. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation of application Ser. No. 10/667,040 filed on Sep. 22, 2003, which is a continuation of application Ser. No. 09/882,536 filed on Jun. 14, 2001 and claims priority under 35 U.S.C. 119 of Danish application nos. PA 2000 00932 and PA 2001 00372 filed on Jun. 16, 2000 and Mar. 7, 2001 respectively, and U.S. provisional application Nos. 60/214,470 and 60/275,790 filed on Jun. 27, 2000 and Mar. 14, 2001 respectively. The benefit of application Ser. No. 09/882,536 filed on Jun. 14, 2001 in the U.S. is claimed under 35 U.S.C. 120, the contents of which are fully incorporated herein by reference.
BACKGROUND OF THE INVENTION
The invention relates to syringes by which a dose can be set by rotating a dose setting member and by which an injection button elevates from an end of the syringe a distance proportional to the set dose and wherein the set dose can be injected by pressing home the injection button to its not elevated position.
An almost classic pen of this type is described in EP 327 910.
By setting a dose on this pen a tubular member forming an injection button is screwed up along a threaded piston rod a distance corresponding to the distance said piston rod must be moved to inject the set dose. The tubular member simply forms a nut which is during the dose setting screwed away form a stop and which is during the injection pressed back to abutment with said stop and the force exerted on the button is directly transmitted to the a piston closing one end of an ampoule in the syringe which ampoule contains the medicament to be injected. When the piston is pressed into the ampoule the medicament is pressed out through a needle mounted through a closure at the other end of the ampoule. By time it has been wanted to store larger amount in the ampoules, typically 3 ml instead of 1.5 ml. As it has not been appropriate to make the syringe longer the ampoule is instead given a larger diameter, i.e. the area of the piston facing the medicament in the ampoule has been doubled and consequently the force which has to be exerted on the piston to provide the same pressure as previously inside the ampoule has been doubled. Further the distance the piston has to be moved to inject one unit of the medicament has been halved.
This development is not quite favourable, as especially users having reduced finger strength have their difficulties in pressing the injection button, a problem that is further increased when still thinner needles are used to reduce the pain by injection. Also with quite small movements of the button it is difficult to feel whether the button is moved at all and by injection of one unit from a 3 ml ampoule the piston and consequently the injection button has to be moved only about 0.1 mm.
Consequently a wish for a gearing between the injection button and the piston has occurred so that the button has a larger stroke than has the piston. By such a gearing the movement of the injection button is made larger and the force, which has to be exerted on the injection button, is correspondingly reduced.
In EP 608 343 a gearing is obtained by the fact that a dose setting element is screwed up along a spindle having a thread with a high pitch. When said dose setting element is pressed back in its axial direction the thread will induce a rotation of said dose setting element, which rotation is via a coupling transmitted to a driver nut with a fine pitch which driver nut will force a threaded not rotatable piston rod forward.
A similar gearing is provided in WO 99/38554 wherein the thread with the high pitch is cut in the outer surface of a dose setting drum and is engaged by a mating thread on the inner side of the cylindrical housing. However, by this kind of gearing relative large surfaces are sliding over each other so that most of the transformed force is lost due to friction between the sliding surfaces. Therefore a traditional gearing using mutual engaging gear wheels and racks is preferred.
From WO 96/26754 is known an injection device wherein two integrated gear wheels engages a rack fixed in the housing and a rack inside a plunger, respectively. When the plunger is moved axially in the housing the rack inside this plunger can drive the first gear wheel to make the other integral gear wheel move along the fixed rack in the housing. Thereby the gear wheel is moved in the direction of the plunger movement but a shorter distance than is this plunger and this axial movement of the integrated gear wheels is via a housing encompassing said gear wheels transmitted to a piston rod which presses the piston of an ampoule further into this ampoule. However, the rack inside the plunger is one of a number axial racks provided inside said plunger. These racks alternates with untoothed recesses, which allow axial movement of the plunger without the first gear wheel being in engagement with a rack in this plunger. This arrangement is provided to allow the plunger to be moved in a direction out of the housing when a dose is set. When the plunger is rotated to set a dose it is moved outward a distance corresponding to one unit during the part of the rotation where the first gear wheel passes the untoothed recess, thereafter the first gear wheel engages one of the racks so the set unit can be injected, or the rotation can be continued to make the first gear wheel pass the next recess during which passing the set dose is increased by one more unit and so on until a dose with the wanted number of units is set.
A disadvantage by this construction is that the teeth of the racks and gearwheels alternating have to be brought in and out of engagement with each other with the inherit danger of clashing. As only a few racks separated by intermediary untoothed recess can be placed along the inner surface of the plunger only few increments can be made during a 360 degree rotation.
SUMMARY OF THE INVENTION
It is an objective of the invention to provide an injection device, which combines the advantages of the devices according to the prior art without adopting their disadvantages and to provide a device wherein is established a direct gearing, i.e. a gearing by which more transformations of rotational movement to linear movement and linear movement to rotational movement are avoided, between the injection button and the piston rod.
This can be obtained by an injection device comprising a housing wherein a piston rod threaded with a first pitch is non rotatable but longitudinally displaceable guided, a nut engaging the thread of the piston rod which nut can be screwed along the threaded piston rod away from a defined position in the housing to set a dose and can be pressed back to said defined position carrying the piston rod with it when the set dose is injected, a dose setting drum which can be screwed outward in the housing along a thread with a second pitch to lift an injection button with it up from the proximal end of the housing, which injection device is according to the invention characterised in that a gearbox is provided which provides a gearing between the axial movements of the injection button and the nut relative to the housing which gearing has a gearing ratio corresponding to the ratio of said second and first pitch.
In a preferred embodiment the gearing between the movements of the injection button and the nut is obtained by the gearbox comprising at least one gear wheel carried by a connector which projects from the gear box longitudinally displaceable but non rotatable relative to said gearbox and is integral with the nut, a first rack integral with a first element of the gearbox, which element is rotational but not longitudinally displaceable relative to the housing, and second element carrying a second rack projecting from said gearbox longitudinally displaceable but non rotatable relative to said first element and being coupled to the injection button to follow longitudinal movements of said button, the at least one gear wheel engaging the first and the second rack, respectively, and being dimensioned to provide a gearing by which a longitudinal movement of the second rack is transformed to a longitudinal movement of the connector with a gearing ratio for the mentioned longitudinal movements of the second rack and the connector relative to the housing, which gearing ratio corresponds to the ratio of said second to said first pitch.
In such a device only the forces necessary to drive the dose setting drum are transformed by a thread with a high pitch whereas the forces necessary to move the piston by injection is transmitted to said piston through a conventional gear with constantly engaging gears and racks.
The piston rod is provided with a stop for the movement of the nut along the thread of said piston rod. This way a dose setting limiter is provided in the classic way, which involves no additional members to prevent setting of a dose exceeding the amount of liquid left in the ampoule.
In the following the invention is described in further details with references to the drawing, wherein
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 schematically shows a sectional view of an injection device according to the invention, and
FIG. 2 shows schematically a sectional view of the gear box along the line I-I in FIG. 1 ,
FIG. 3 shows a longitudinal sectional view in the dose setting part of another embodiment of an injection device according to the invention,
FIG. 4 shows a longitudinal sectional view perpendicular to the view in FIG. 3 , and
FIG. 5 shows an exploded picture of the of the device shown in FIGS. 3 and 4 .
DETAILED DESCRIPTION
In the device shown in FIG. 1 an elongated cylindrical housing 1 has a partitioning wall 2 which divides the housing in a compartment containing a dose setting mechanism and a compartment 3 designed for the accommodation of a not shown ampoule. A threaded piston rod 4 has a not round cross section by which it fits through a central opening in the wall 2 so that the piston rod 4 can be displaced longitudinally through the central opening in the wall 2 but not rotated relative to this wall.
Concentrically with the housing 1 the wall 2 carries on its side turning away from the compartment 3 a tubular element 5 which is at a part of it adjacent to the wall 2 provided with an outer thread 6 and which has at its free end a circumferential recess 7 . A ring shaped coupling element 8 on a gear box 9 engages the recess 7 . By this coupling the gearbox is fixed in the housing 1 in a way that allows the gearbox 9 to rotate in the housing but not to be axially displaced relative to said housing.
In the gearbox 9 a gear wheel assembly comprising two integral gear wheels is journaled on a shaft 11 , which runs perpendicular to the longitudinal axis of the device between two axial connection bars 12 . The connection bars 12 project from the gear box towards the partition wall 2 and are connected to a nut 13 which adjacent to the wall 2 engages the thread of the piston rod 4 . The gear wheel assembly comprises a gear wheel 14 with a large diameter engaging the teeth of a rack 15 which is guided in the gear box to be displaced in the longitudinal direction of the device, and a gear wheel 16 with a small diameter engaging a rack 10 in FIG. 2 extending in the longitudinal direction of the device on the inner wall of the gearbox 9 . The gear wheel 16 with the small diameter may be divided into two gear wheels placed on each side of the of the gear wheel 14 , and the rack on the inner wall of the gearbox 9 may have a longitudinal recess without any teeth to make room for the gear wheel 14 .
A tubular dose setting drum 17 fitting into the housing 2 is at an end provided with an internal thread mating and engaging the outer thread 6 of the tubular element 5 and has at its other end a part with enlarged diameter forming a dose setting button 18 . Due to the engagement with the thread 6 the dose setting drum 17 may be screwed in and out of the housing to show a number on a not shown helical scale on its outer surface in a not shown window in the housing 1 .
A bottom 19 in a deep cup shaped element, which has a tubular part 20 fitting into the dose setting drum 17 and encompassing the gearbox 9 , forms an injection button. Coupling means between the dose setting drum 17 and the cup shaped element ensures that rotation of the dose setting drum 17 is transmitted to the cup shaped element. Further the inner wall of the tubular part 20 has longitudinal recesses 22 engaged by protrusions 23 on the gearbox 9 so that rotation of the dose setting drum 17 via the cup shaped element is transmitted to the gearbox 9 .
At the edge of the open end of the cup shaped element a rosette of V-shaped teeth are provided, which teeth engage a corresponding rosette of V-shaped teeth 24 on a ring 25 which is pressed against the edge of the cup shaped element by a spring 26 which is compressed between a not toothed side of the ring 25 and a round going shoulder 27 on the inner wall of the dose setting drum 17 at an inner end of the inner thread of this drum. The ring is provided with an inner recess, which is engaged by a longitudinal rib 28 on the tubular element 5 so that the ring 25 can be displaced in the axial direction of the device but cannot be rotated relative to the housing 1 . Thereby a click coupling is established which makes a click noise when the V-shaped teeth at the edge of the cup shaped element by rotation of this element rides over the V-shaped teeth of the ring 25 .
A head 29 on the projecting end of the rack 15 is with a play fixed at the bottom of the cup shaped element between the bottom 19 forming the injection button and an inner wall 30 near this bottom. The rack is fixed in a position with its head pressed against the wall 30 by a spring 31 between the bottom 19 and the head 29 .
To set a dose the dose setting button 18 is rotated to screw the dose-setting drum 17 up along the thread 6 . Due to the coupling 21 the cup shaped element will follow the rotation of the dose-setting drum 17 and will be lifted with this drum up from the end of the housing 1 . By the rotation of the cup shaped element the V-shaped teeth 24 at the edge of its open end will ride over the V-shaped teeth of the non rotatable ring 25 to make a click sound for each unit the dose is changed. A too high set dose can be reduced by rotating the dose setting button 18 in the opposite direction of the direction for increasing the dose. When the dose setting drum is screwed up along the thread 6 on the tubular element 5 the ring 25 will follow the dose setting drum in its axial movement as the spring 26 is supported on the shoulder 27 . The spring will keep the V-shaped teeth of the ring 25 and the cup shaped element in engagement and maintain in engagement the coupling 21 , which may comprise A-shaped protrusions 32 on the cup shaped element engaging A-shaped recesses in an inner ring 33 in the dose setting button 18 .
The rotation of the dose setting button 18 and the cup shaped element is further transmitted to the gearbox 9 through the protrusions 23 on this gearbox engaging the longitudinal recesses 22 in the inner wall of the tubular part 20 of said cup shaped element. The rotation of the gearbox 25 is through the connection bars 12 transmitted to the nut 13 , which is this way screwed up along the thread of the piston rod 4 and lifted away from its abutment with the wall 2 when a dose it set. As the dose is set by moving the nut 13 on the very piston rod which operates the piston in the not shown ampoule in the compartment 3 a dose setting limiter, which ensures that the size of the set dose does not exceed the amount of medicament left in the ampoule, can easily be established by providing the piston rod 4 with a stop 35 which limits the movement of the nut 13 up along the piston rod 4 .
Due to the confinement of the head 29 in the space between the bottom 19 and the wall 30 of the cup shaped element, the rack 15 is drawn with the injection button outward. Also the axial movement of the nut 13 relative to the housing 1 will be transmitted to the gear wheel assembly through the connection bars 12 and this movement will through the gear-box induce an outward movement of the rack 15 . This induced outward movement have to be the same as the outward movement induced by outward movement of the injection button. This is obtained by dimensioning the gear wheels of the gearbox 9 so that the gear ratio for the movements of the connection bars 12 and the rack 15 relative to the housing corresponds to the ratio of the pitches for the thread on the piston rod and for the thread 6 for the longitudinal movement of the dose setting drum 17 .
To inject a set dose the injection button is pressed by pressing on the bottom 19 . In the initial phase of the pressing the spring 31 is compressed where after the pressing force is directly transmitted to the head 29 of the rack 15 and this way to the rack 15 itself. Through the gear box 9 the force is transformed and is transmitted through the connection bars 12 to the nut 13 which will press the piston rod 4 into the compartment 3 until the dose-setting drum 17 abuts the wall 2 .
During the initial phase of the movement of the injection button the A-shaped protrusions 32 on the cup shaped element will be drawn out of their engagement with the A-shaped recesses in the ring 33 . The dose-setting drum 17 can now rotate relative to the injection button and will do so when the A-shaped protrusions 32 press against a shoulder 34 at the bottom of the dose setting button 18 . Only a force sufficient to make the dose setting drum rotate to screw itself downward along the thread 6 is necessary as the force necessary to make the injection is transmitted to the piston rod 4 through the gearbox 9 . A helical reset spring 36 concentric with the dose setting drum can be mounted at the lower end of this drum and can have one end anchored in the dose setting drum 17 and the other end anchored in the wall 2 . During setting of a dose this spring may be tighter coiled so that on the dose setting drum it exerts a torque approximately corresponding to the torque necessary to overcome the friction in the movement of the dose setting drum along the thread 6 so that the force which the user have to exert on the injection button is only the force necessary to drive the piston rod into an ampoule to inject the set dose.
It shall be noticed that use of only one size gear wheel which engages as well the rack 15 , which is movable relative to the gear box 9 , as the rack 10 , which is unmovable relative to the gear box, provides a gearing ratio of 2:1 for the longitudinal movement relative to the syringe housing 1 for the movable rack 15 and the connector 12 , which carries the shaft 11 of the gear wheel.
FIGS. 3 and 4 shows a preferred embodiment wherein only one size gear wheel is used and wherein elements corresponding to elements in FIGS. 1 and 2 are given the same references as these elements with a prefixed “1”.
For manufacturing reasons minor changes are made. So the partitioning wall 102 and the tubular element 105 are made as two parts which are by the assembling of the device connected to each other to make the assembled parts act as one integral part. The same way the dose setting drum 117 and the dose setting button 118 are made as two parts, which are fixed firmly together.
A circumferential recess 107 is provided as an outer recess at the free end of the tubular part 105 and a ring shaped coupling element is provided as an inner bead 108 on the gear-box element 109 which bead engages the recess 107 to provide a rotatable but not axially displaceable connection between the tubular part 105 and the gearbox.
A tubular element 120 having ridges 122 which engages recesses 123 on the gearbox is at its upper end closed by a button 119 from which a force provided by pressing this button is transmitted to the tubular element 120 .
The gearbox is formed by two shells, which together form a cylinder fitting into the tubular element where the shells are guided by the engagement between the ridges 122 and the recesses 123 . Racks 110 and 115 are provided along edges of the shells facing each other. One shell forming the gearbox part 109 is provided with the inner bead 108 , which engages the circumferential recess 107 at the end of the central tubular part 105 and carries the rack 110 . The other shell is axially displaceable in the tubular element 120 and forms the rack 115 . At its outer end projecting from the gearbox the shell carrying the rack 115 is provided with a flange 140 which is positioned in a cut out 141 in the end of the tubular element 120 carrying the button 119 so that this button and the tubular element 120 can be moved so far inward in the device that the engagement of the teeth 132 and 133 can be released before the button 119 abuts the flange 140 .
A tubular connection element 112 connects the threaded piston rod 104 with the gearbox. At its end engaging the piston rod 104 the connection element has a nut 113 with an internal thread mating the external thread of the piston rod. At its end engaging the gear box the connection element is provided with two pins 111 projecting perpendicular to the longitudinal axis of the connection element 112 at each side of this element. Each pin 111 carries a gear wheel 114 which is placed between and engages the two racks 110 and 115 . This way the connection element 112 will be rotated with the gear box but can be displaced axially relative to said gear box when the racks 110 and 115 are moved relative to each other. In practice it will be the rack 115 , which is moved relative to the gearbox element 109 and the housing and will by the shown construction result in a movement of the connection element 112 relative to housing a distance which is half the distance which the rack 115 is moved. A ring 125 which is at its periphery provided with a rosette of teeth 124 and has a central bore fitting over the central tube in the housing 101 so that this ring 125 can be axially displaced along said central tube 105 , but internal ridges 128 in the central bore of the ring 125 engages longitudinal recesses 137 in the central tube to make the ring non rotatable in the housing so that a rosette of teeth at the edge of the tubular element 120 can click over the teeth 124 of the ring when said tubular element is rotated together with the dose setting drum 117 . A spring 126 working between the ring 125 and an internal shoulder 127 provided in the dose setting drum 117 makes the ring follow the tubular element 120 when this element with the dose setting drum is moved longitudinally in the housing. To make the dose setting drum easy rotatable, especially when said dose setting drum is pressed inward in the housing, a roller bearing having an outer ring 142 supported by the shoulder 127 and an inner ring 143 supporting a pressure bushing 144 which supports the spring 126 . By the provision of this smooth running support only very small axial forces are needed to rotate the dose setting drum 117 back to its zero position when a set dose is injected. This solution replaces the provision of a reset spring as the spring 36 in FIG. 1 . The bearing is shown as a radial bearing but can be replaced by an axial bearing | A medication dispensing device with a housing and a member wherein the member is moveable in a distal direction is useful in delivering medication to a patient. A fluid container can be used with the device and often has a moveable piston at one end and an outlet at the other. The member receives a force from a user and drives the piston in the distal direction to expel medication. A intermediate system is disposed between the member and the piston including a gear set that has a pinion in meshed engagement with a rack. The system allows the member to move a greater distance than the piston moves thereby increasing the force on the piston. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This is a non-provisional application based upon U.S. patent application Ser. No. 14/534,927, entitled “AGRICULTURAL TILLAGE IMPLEMENT WHEEL CONTROL”, filed Nov. 6, 2014, which is based on U.S. provisional patent application Ser. No. 61/903,529, entitled “AGRICULTURAL TILLAGE IMPLEMENT WHEEL CONTROL”, filed Nov. 13, 2013, both of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to agricultural implements, and, more particularly, to agricultural tillage implements.
[0004] 2. Description of the Related Art
[0005] Farmers utilize a wide variety of tillage implements to prepare soil for planting. Some such implements include two or more sections coupled together to perform multiple functions as they are pulled through fields by a tractor. For example, a field cultivator is capable of simultaneously tilling soil and leveling the tilled soil in preparation for planting. A field cultivator has a frame that carries a number of cultivator shanks with shovels at their lower ends for tilling the soil. The field cultivator converts compacted soil into a level seedbed with a consistent depth for providing excellent conditions for planting of a crop. Grass or residual crop material disposed on top of the soil is also worked into the seedbed so that it does not interfere with a seeding implement subsequently passing through the seedbed.
[0006] Tillage equipment prepares the soil by way of mechanical agitation of various types, such as digging, stirring, and overturning. Examples of which include ploughing (overturning with moldboards or chiseling with chisel shanks), rototilling, rolling with cultipackers or other rollers, harrowing, and cultivating with cultivator shanks.
[0007] Tillage is often classified into two types, primary and secondary. There is no strict definition of these two types, perhaps a loose distinction between the two is that tillage that is deeper and more thorough is thought of as primary, and tillage that is shallower is thought of as secondary. Primary tillage such as plowing produces a larger subsurface difference and tends to produce a rough surface finish, whereas secondary tillage tends to produce a smoother surface finish, such as that required to make a good seedbed for many crops. Harrowing and rototilling often combine primary and secondary tillage into one operation.
[0008] Wheels are often integral with tillage implements and are used for both transportation of the implement, and for depth control of the tillage elements. The prior art includes control systems that raise and lower the implement as an entire unit, which can result in uneven tillage across the implement width of today's wider equipment.
[0009] What is needed in the art is an easy to use mechanism for depth control of an agricultural tillage implement.
SUMMARY OF THE INVENTION
[0010] The present invention provides a tillage implement that has several tilling sections with the ability to independently control the depth of the tilling elements of the various sections.
[0011] The invention in one form is directed to an agricultural tillage implement that includes a main section having a hitch extending in a travel direction, a plurality of foldable wing sections coupled with the main section, a plurality of ground engaging tilling elements, a plurality of wheel assemblies and a control system. The tilling elements are coupled to the main section and wing sections. Each of the wheel assemblies include an actuator. The wheel assemblies include a first plurality of wheel assemblies associated with the main section and a second plurality of wheel assemblies associated with the plurality of wing sections. The actuators of the first plurality of wheel assemblies being independent of the actuators of the second plurality of wheel assemblies. The control system is configured to actuate the actuators to control a depth of tilling elements in each of the sections when the implement is in a field mode.
[0012] The invention in another form is directed to a control system of an agricultural tillage implement. The implement has a main section including a pull hitch extending in a travel direction, a plurality of foldable wing sections coupled with the main section and a plurality of wheel assemblies, each of the sections having at least one tilling element that is engageable with the ground. The control system includes a controller and a plurality of actuators. At least one actuator is associated with each of the wheel assemblies. The plurality of wheel assemblies include a first plurality of wheel assemblies associated with the main section and a second plurality of wheel assemblies associated with the plurality of wing sections. The actuators of the first plurality of wheel assemblies are controlled independently of the actuators of the second plurality of wheel assemblies by the controller. The controller is configured to actuate the actuators to control a depth of the tilling elements in each of the sections while the implement is in a field mode.
[0013] The invention in yet another form is directed to a method of controlling profile heights of a plurality of sections of tilling assemblies of an agricultural implement. The method includes the step of independently actuating a plurality of actuators to control a depth of tilling elements in each of a plurality of foldable sections of the implement when the implement is in a field mode.
[0014] An advantage of the present invention is that the implement has a decreased profile in the transport mode.
[0015] Another advantage of the present invention is that the control system can be used to level the implement from side-to-side.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, wherein:
[0017] FIG. 1 is a top perspective view of an embodiment of an agricultural tillage implement of the present invention, in the form of a field cultivator, in an unfolded position;
[0018] FIG. 2 is a front view of the field cultivator shown in FIG. 1 ;
[0019] FIG. 3 is a top perspective view of the field cultivator shown in FIGS. 1-2 , with the outer wing sections folded to a transport position;
[0020] FIG. 4 is a front view of the field cultivator shown in FIG. 3 , with the outer wing sections folded to the transport position;
[0021] FIG. 5 is a top perspective view of the field cultivator shown in FIGS. 1-4 , with the middle wing sections folded to a transport position;
[0022] FIG. 6 is a front view of the field cultivator shown in FIG. 5 , with the middle wing sections folded to the transport position;
[0023] FIG. 7 is a top perspective view of the field cultivator shown in FIGS. 1-6 , with the inner wing sections folded to a transport position;
[0024] FIG. 8 is a front view of the field cultivator shown in FIG. 7 , with the inner wing sections folded to the transport position;
[0025] FIG. 9 is a perspective view of part of the main frame section of the field cultivator of FIGS. 1-8 ; and
[0026] FIG. 10 is a side view of the field cultivator of FIGS. 1-9 , with a primary focus on a wing section.
[0027] Corresponding reference characters indicate corresponding parts throughout the several views. The exemplification set out herein illustrates embodiment of the invention, in one form, and such exemplification is not to be construed as limiting the scope of the invention in any manner.
DETAILED DESCRIPTION OF THE INVENTION
[0028] Referring now to the drawings, and more particularly to FIG. 1 , there is shown an embodiment of a tillage implement of the present invention. In the illustrated embodiment, the tillage implement is in the form of a field cultivator 10 for tilling and finishing soil prior to seeding.
[0029] Field cultivator 10 is configured as a multi-section field cultivator, and includes a center frame section 12 , also referred herein as a main section 12 , and a plurality of wing sections 14 , 16 and 18 . In the illustrated embodiment, field cultivator 10 has a triple-fold configuration with three left wings sections designated 14 A, 16 A and 18 A, and three right wing sections designated 14 B, 16 B and 18 B. Wing sections 14 A and 14 B are each inner wing sections, wing sections 16 A and 16 B are each middle wing sections, and wing sections 18 A and 18 B are each outer wing sections.
[0030] Center frame section 12 is the center section that is directly towed by a traction unit, such as an agricultural tractor (not shown). Center frame section 12 generally functions to carry a shank frame 20 for tilling the soil, and a rear auxiliary implement 22 for finishing the soil. A pull hitch 24 extends forward from shank frame 20 , and is coupled with the traction unit in known manner.
[0031] Rear auxiliary implement 22 includes a spring tooth drag 26 and a rolling (aka, crumbler) basket 28 which coact with each other to finish the soil. However, rear auxiliary implement 22 can be differently configured, such as a spike tooth drag, cultivator shanks, etc.
[0032] Shank frame 20 generally functions to carry cultivator shanks 30 with shovels 32 at their lower ends for tilling the soil. Rear lift wheels 34 are used for raising and lowering the shank frame 20 with a hydraulic lift cylinder (not specifically visible in FIGS. 1 and 2 ), and a pair of front gauge wheels 36 are used to level the shank frame 20 during a field operation.
[0033] Similarly, each inner wing section 14 A and 14 B, middle wing section 16 A and 16 B, and outer wing section 18 A and 18 B includes a shank frame 20 for tilling the soil, a rear auxiliary implement 22 for finishing the soil, rear lift wheels 34 and front gauge wheels 36 . These components are slightly different from but still similar to the like-named components described above with regard to center frame section 12 , and are not described in further detail herein.
[0034] During use, it is periodically necessary to move the field cultivator 10 from an unfolded (operating) position to a folded (transport) position. First, each outer wing section 18 A and 18 B is folded laterally inward and over a respective middle wing section 16 A and 16 B ( FIGS. 3 and 4 ). With the outer wing sections 18 A and 18 B in the folded state, each middle wing section 16 A and 16 B is then folded laterally inward and over a respective inner wing section 14 A and 14 B ( FIGS. 5 and 6 ). With the middle wing sections 16 A and 16 B in the folded state, each middle wing section 16 A and 16 B is then folded laterally inward and over the center frame section 12 ( FIGS. 7 and 8 ). To unfold the field cultivator 10 and transform back to the field or operating position shown in FIGS. 1 and 2 , the folding sequence described above is simply reversed.
[0035] The outer wing sections 18 , middle wing sections 16 and inner wing sections 14 are stacked together in a vertically arranged stack over the center frame section 12 when in the folded state. To allow this type of nested stacking configuration, each of the wing sections 14 , 16 and 18 have a pivot axis 38 , 40 and 42 , respectively, which is vertically offset to allow the wing sections to lie flat against the laterally inward shank frame 20 /frame section 12 when in the folded state. The middle wing sections 16 have a pivot axis 40 that is vertically higher than pivot axes 38 and 42 of adjacent wing sections 14 and 18 , when in the unfolded state.
[0036] Different countries and states have different regulatory highway requirements concerning oversized vehicles on the road. In the US, some states exempt agricultural equipment from such regulations, while others require that any type of vehicle on a road must comply with the oversized vehicle regulations. In Europe, the regulations may be more strict concerning the height and width of vehicles which may travel on a road without being accompanied by an escort vehicle. With the triple-fold field cultivator 10 of the present invention, the overall frontal profile dimensions when in the folded state fit within regulatory requirements for both the US and Europe. More particularly, with all of the wing sections 14 , 16 and 18 in the folded state, the field cultivator 10 is then in a transport position with an overall frontal profile having dimensions with a maximum width “W” of no greater than approximately 20 feet, preferably approximately 18 feet wide, and a height “H” of no greater than approximately 14 feet, preferably approximately 13 feet, 6 inches high ( FIG. 8 ).
[0037] These maximum frontal profile dimensions include all of the shank frames 20 , shanks 30 , rear lift wheels 34 and front gauge wheels 36 , when in the folded state. The rear auxiliary implements 22 are considered to be add-ons to the main field cultivator 10 , and may be outside these overall frontal profile dimensions, at least if not folded upwardly for the transport position. However, it is the intention that all of field cultivator 10 , including the rear auxiliary implements 22 , be within these maximum frontal profile dimensions when in the transport position.
[0038] Now, additionally referring to FIGS. 9 and 10 there is shown further details of implement 10 . Main section 12 is shown in FIG. 9 with wheel assemblies 50 having actuators 54 , which provide depth level control for main section 12 when implement 10 is in field mode and support for the folded implement 10 while in transport mode.
[0039] A typical wheel assembly 52 is shown for one of the wing sections 14 , 16 and 18 in FIG. 10 . Wheel assemblies 52 include actuators 56 , a linkage system 60 and an adjustable link 62 . A controller 58 (shown abstractly in the figures) orchestrates the movement of wheel assemblies 50 and 52 in field and transport modes and during the transition to/from the field and transport modes.
[0040] Wheel assemblies 50 are shown having actuator 54 coupled more directly to the rear wheels and a linkage system is used to move the wheels that are to the fore of the rear wheels. Wheel assemblies 52 have actuator 56 positioned between the rear and fore wheels with linkage system 60 coupling both the rear and fore wheels for coordinated movement. Adjustable link 62 allows for an independent manual fore/aft leveling adjustment of each section.
[0041] Actuators 54 and 56 , are under the independent and individual control of controller 58 so that sections 12 - 18 can each be individually adjusted for depth control of shovels 32 (which are tillage elements) of each section in a manner substantially independent of the other sections while in the field mode of operation. As implement 10 is transitioned from the field mode to the transport mode and the sections are being folded together, controller 58 causes wheel assemblies 52 to go from the fully extended position, as shown in FIG. 10 with actuator 56 fully extended, to being partially retracted as seen in the folded wing sections of FIG. 6 . This effectively lowers the profile of each wing section 14 - 18 as the particular wing section is folded. While controller 58 may be a set of valves manually controlled by an operator, it is contemplated that controller 58 would be an electronic control system that controls the sequence of lowering the profile of each wing section, as it is being folded by the actuators used for the purpose of folding wing sections 14 - 18 .
[0042] The present invention advantageously independently controls the depth of the tilling elements while implement 10 is in the field mode. The prior art used a common rocker shaft between lift wheels on the main frame, which is not as flexible as the present invention. The present invention uses the depth control mechanism to also minimize the height profile of each section as wing sections 14 - 18 are folded for transport and the process is reversed when implement 10 transitions from the transport mode to the field mode.
[0043] While this invention has been described with respect to at least one embodiment, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims. | An agricultural tillage implement includes a main section including a hitch extending in a travel direction, a plurality of foldable wing sections coupled with the main section, a plurality of ground engaging tilling elements, a plurality of wheel assemblies and a control system. The tilling elements are coupled to the main section and wing sections. Each of the wheel assemblies include an actuator. The wheel assemblies include a first plurality of wheel assemblies associated with the main section and a second plurality of wheel assemblies associated with the plurality of wing sections. The actuators of the first plurality of wheel assemblies being independent of the actuators of the second plurality of wheel assemblies. The control system is configured to actuate the actuators to control a depth of tilling elements in each of the sections when the implement is in a field mode. | 0 |
RELATED APPLICATION
The present application is a continuation-in-part application of copending U.S. patent application Ser. No. 08/679,930 for NEUTRAL METAL ALKANOATE MICRONUTRIENT SOLUTIONS AND METHOD OF MANUFACTURING SAME, filed Jul. 15, 1996.
FIELD OF THE INVENTION
This invention relates to micronutrient compositions suitable for application to crops and having increased aqueous solubility alone and in combination with fertilizers. More particularly, this invention relates to aqueous ammoniacal ionic solutions of metal alkanoates and to methods of manufacturing same.
BACKGROUND OF THE INVENTION
Fertilizers and plant additives are commonly applied to the soil in which crops are to be grown and may also be broadcast after plants have emerged from the soil. For example, aqueous ammoniacal ionic solutions of alkanoates having two to six carbon atoms have proven effective in stimulating plant growth in corn, soy beans, wheat and other crops. Metal ammonium alkanoates have proven especially effective with agriculturally acceptable metals selected from the group consisting of boron, calcium, copper, iron, magnesium, manganese, molybdenum, potassium, and zinc.
More particularly, U.S. Pat. No. 4,352,688 for "Nitrogen Fertilizers" to Ott, incorporated herein by reference, teaches that low molecular weight alkanoic acids and alkanoate anions thereof, particularly acetic acid and acetate ions, effectively promote plant growth and yield by enhancing the ability of nitrogen fertilizers. U.S. Pat. No. 3,909,229 for "Plant Nutrients" to Ott, also incorporated herein by reference, teaches aqueous ammoniacal ionic solutions of zinc carboxylates, for example zinc acetate in combination with ammonia, as effective fertilizers. U.S. Pat. No. 3,997,319 for "Fertilizing Method" to Ott, incorporated herein by reference, teaches the application of substantially anhydrous liquid ammonia containing an ionic solution of a zinc carboxylate to soil below the surface of the soil, in order to supply zinc and nitrogen to plants growing in the soil.
One agricultural crop additive of the class of basic ammoniacal ionic solutions of zinc carboxylates described above is commercially available under the ACA® Concentrate 15-0-0 trade mark from Platte Chemical Company of Greeley, Colo. ACA® Concentrate 15-0-0 is currently available as a liquid containing 15% by weight ammoniacal nitrogen and 17% by weight zinc. ACA® Concentrate has a pH of approximately 11 and a strong ammonia smell. It is typically applied at a rate of a pint to 1/8 pint per acre. Because application of the solution is at relatively low rates per acre, application techniques are generally understood to require application in conjunction with an anhydrous ammonia, solid nitrogen fertilizer carrier, or fertilizer solution containing substantial amounts of phosphates.
Dilution of ACA® Concentrate in water at ratios of greater than 1:8 ACA® Concentrate:water is generally prohibited because undesired precipitation occurs. It is generally believed that the zinc tetramine acetate in the ACA® Concentrate remains in solution at pH 11, but excess dilution with water causes the pH to drop and a zinc ammonium complex to precipitate out. Thus, while in many circumstances it would be preferable to apply ammoniacal ionic solutions of metal alkanoates with water by overhead sprinkler systems, in-furrow, broadcast on the ground or in the air, using side dress techniques or with drip irrigation techniques, use of such application techniques has not been entirely successful.
Application of ammoniacal ionic solutions of metal alkanoates with a wide variety of liquid fertilizers, herbicides and pesticides would also be preferred, but solubility problems of such metal alkanoate solutions limit use of such techniques. These solubility problems partly relate to the water dilution problems previously mentioned. Other solubility problems are also present. For example, ACA® Concentrate is not readily soluble in all solutions.
While the solubility problems outlined above may be partially solved by application of the ammoniacal ionic metal alkanoate solutions with anhydrous ammonia, application of anhydrous ammonia has other associated problems. Anhydrous liquid ammonia is typically injected below the soil surface, under pressure, in the fall-after the end of the growing season, in early spring--prior to planting, or in late spring-post-emergence, i.e. after a crop has germinated and leafed out. While anhydrous liquid ammonia is readily assimilated by plants and thus is a preferred fertilizer, the pressurized injection methods conventionally used are not suitable for use under wet or stormy conditions. When weather conditions are unsuitable, growers may skip scheduled early spring, late spring or fall applications of anhydrous liquid ammonia. When this occurs, crop yields are likely to be reduced. Moreover, for any aqueous ammoniacal ionic solutions of metal alkanoates or other crop additives which were to be applied with anhydrous ammonia, a missed application of anhydrous ammonia also results in a missed application of the crop additive.
It is against this background that the significant improvements and advancements of the present invention have taken place.
OBJECTS OF THE INVENTION
It is the principal object of the present invention to develop micronutrient solution that can be diluted with water without undesired precipitation and without an ammoniacal smell or other unpleasant odor.
It is a further object of the present invention to achieve the root stimulation effects of aqueous ammoniacal ionic solution of metal alkanoates in crops using a micronutrient solution which can be readily diluted with water.
It is a yet further object of the present invention to apply a micronutrient solution have the aforementioned qualities, to plants in combination with a wide variety of fertilizer solutions.
SUMMARY OF THE INVENTION
In accordance with the major aspects of the present invention, a micronutrient composition containing a substantially neutral solution of metal alkanoates is disclosed. The preferred embodiments of the micronutrient composition of the present invention are readily diluted with water, and do not exhibit undesired precipitation. The micronutrient compositions of the present invention maintain solubility at lowered temperatures and in a wide variety of liquid fertilizers.
The preferred method of manufacturing the micronutrient compositions of the present invention involve the dispersion of a metal salt, most preferably zinc oxide, in water. Although zinc oxide is the most preferred metal oxides from which the compositions of the present invention may be manufactured, other metal salts may be used as a source of agriculturally acceptable metals selected from the group consisting of boron, calcium, copper, iron, magnesium, manganese, molybdenum, potassium, sodium and zinc. Anhydrous ammonia is then slowly added to the metal salt dispersion. Thereafter, a carboxylic acid, preferably one with two to six carbon atoms such as acetic and propionic acid, most preferably acetic acid, is added slowly, with cooling, until the components are dissolved. The resulting micronutrient solution is then cooled. The micronutrient solution of the present invention has a pH of from 4 to 9, preferably from 6 to 7 and most preferably from 6.5 to 7.0.
When utilizing the aforementioned method to manufacture the most preferred micronutrient composition of the present invention with zinc oxide and acetic acid, the resulting product has a slightly sweet odor, and preferably has pH of approximately 6.5 to 7.0. When applied to corn, this micronutrient solution it has been found to effectively promote root growth.
A more complete appreciation of the present invention and its scope can be obtained from understanding the following detailed description of presently preferred embodiments of the invention, and the appended claims.
DETAILED DESCRIPTION OF THE INVENTION
In accordance with the present application, it has been discovered that an improved composition for application to crops is obtained by dispersing a metal salt, most preferably zinc oxide, in water, and then adding ammonia, most preferably anhydrous ammonia, to the dispersion. A carboxylic acid, for example acetic acid, as added to the basic dispersion, until the contents of the dispersion are solubilized and the solution is substantially neutralized. The resulting micronutrient solutions have a slightly sweet smell, and may be readily diluted in water and in a wide variety of fertilizer solutions. Because of the serious water dilution problems experienced with ammoniacal ionic solutions of zinc acetate, the stability and solubility of the micronutrient solutions of the present invention were unexpected. Indeed, it was expected that when the most preferred composition of the present invention was neutralized with acetic acid, the solution would become so saturated with ammonium acetate that crystallization would occur, especially at lower temperatures. However, even after discovering such was not the case, the ability of such compositions to stimulate root growth remained unknown. As is discussed in further detail below, it has been determined that micronutrient compositions of the present invention manufactured from water, zinc oxide, anhydrous ammonia and acetic acid, do exhibit root stimulation capability when applied to corn.
While metal oxides are a preferable constituent of the micronutrient compositions and methods of the present invention, other metal salts may be used, among which are zinc oxide, zinc hydroxide, zinc sulfate, zinc acetate, zinc chloride, zinc nitrate, zinc citrate, zinc lactate, zinc phosphate, zinc propionate, magnesium acetate, magnesium oxide, magnesium hydroxide, magnesium chloride, magnesium glucoheptonate, magnesium propionate, magnesium sulfate, magnesium lactate, manganese acetate, manganese carbonate, manganese oxide, manganese sulfate, manganese borate, manganese iodide, manganese oleate, manganese sulfide, manganese silicate, manganese dibasic phosphate, calcium oxide, calcium hydroxide, calcium chloride, calcium acetate, calcium propionate, calcium benzoate, calcium gluconate, calcium hypochlorite, calcium molybdate, calcium nitrate, calcium nitrite, calcium phosphate, calcium succinate, calcium tetraborate, calcium thiosulfate, cupric hydroxide, copper acetate, copper sulfate, cupric acetate, cupric benzoate, cupric chlorite, cupric chlorate, cupric formate, cupric sulfate, cuprous acetate, cuprous chloride, cuprous oxide, cuprous sulfite, cuprous iodide, ferric ammonium citrate, ferric ammonium sulfate, ferric formate, ferric chloride, ferric hydroxide, ferric oxide, ferric phosphate, ferrous chloride, ferrous citrate, ferrous phosphate, ferrous lactate, ferrous oxide, ferrous succinate, ferrous iodide, ferrous sulfate, ferrous thiocynate, cobaltic acetate, cobaltic fluoride, cobaltic oxide monohydrate, cobaltic potassium nitrite, sodium tetraborate, sodium molybdate, ammonium molybdate, molybdenum trioxide and molydenum disulfide. The compositions and methods of the present invention are preferably neutralized with carboxylic acid having the formula RCOOH. Exemplary acids include formic, isovaleric, acetic, pivalic, propionic, butanoic, hexanoic, caproic, acrylic, caprylic, butyric capric, isobutyric, lauric, crotonic, mysristic, valeric, palmitic, isovaleric, oleic, pivalic, linoleic, stearic, benzoic, cyclopentanecarboxylic, citric and mixtures thereof. The micronutrient solution of the present invention has a pH of from 4 to 9, preferably from 6 to 7 and most preferably from 6.5 to 7.0. Examples I-XV below describe the manufacture of preferred micronutrient solutions of the present invention.
EXAMPLE I
Water (29.1 grams) was added to a mixing vessel placed in an ice water bath. Powdered zinc oxide (10.8 grams, high purity, French process) was added to the water in the mixing vessel and mixed with cooling until the zinc oxide was evenly dispersed. Anhydrous ammonia (9.6 grams) was metered into the zinc oxide dispersion slowly to produce a basic ammoniacal mixture of zinc oxide. Thereafter, 50.5 grams of 99.9% acetic acid was slowly added with mixing, with the mixture cooled so as to maintain a temperature below 120° F. throughout mixing. After mixing was complete, the resulting solution was cooled to below 100° F. The final micronutrient solution had a pH of approximately 6.8, a specific gravity of 1.237 gm/ml at 25° C., a viscosity of less than 50 centipoise at 70° F., was clear and colorless at 70° F. and pale yellow-green at 0° F., and had a slightly sweet smell. The solution remained liquid after storage at 32° F. for 48 hours and after storage at 0° F. for 48 hours. One gram of the solution was miscible in 99 grams of 10-34-0 fertilizer solution, in 99 grams of a 9-18-9 solution and in 99 grams of a 28-0-0 solution.
EXAMPLE II
Water (29.1 grams) was placed in vessel sitting in an ice water bath. Powdered zinc oxide (10.8 grams) was added to the water in the mixing vessel and mixed, with cooling, until the zinc oxide was evenly dispersed. Anhydrous ammonia (9.6 grams) was metered into the zinc oxide solution slowly to produce a basic, ammoniacal ionic dispersion of zinc oxide, with cooling. Thereafter, 50.5 grams of 99.9% propionic acid was slowly added with mixing, with the mixture cooled so as to maintain a temperature below 120° F. throughout mixing. After mixing was complete, the resulting solution was cooled to below 100° F. The final product had a pH of approximately 6.7, a specific gravity of 1.18 gm/ml at 25° C. and a viscosity of less than 50 centipoise at 70° F. The solution remained liquid after storage at 32° F. for 48 hours and after storage at 0° F. for 48 hours. One gram of the solution was miscible in 99 gm of a 10-34-0 solution, in 99 gm of a 9-18-9 solution and in 99 gm of a 28-0-0 solution.
EXAMPLE III
Water (29.1 grams) was placed in a mixing vessel sitting in an ice water bath. Powdered zinc oxide (10.8 grams) was added to the water in the mixing vessel and mixed, with cooling, until dispersed. Anhydrous ammonia (9.6 grams) was metered into the zinc oxide solution slowly to produce a basic, ammoniacal ionic dispersion of zinc oxide, with cooling. Thereafter, 25.25 grams of 99% acetic acid and 25.15 grams of 99.9% propionic acid was slowly added with mixing, with the mixture cooled so as to maintain a temperature below 120° F. throughout mixing. After mixing was complete, the resulting solution was cooled to below 100° F. The final product had a pH of approximately 7, a specific gravity of 1.20 gm/ml at 25° C. and a viscosity of less than 50 centipoise at 70° F. The solution remained liquid after storage at 32° F. for 48 hours and after storage at 0° F. for 48 hours. One gram of the solution was miscible in 99 gm of a 10-34-0 solution, in 99 gm of a 9-18-9 solution and in 99 gm of a 28-0-0 solution.
EXAMPLE IV
In order to test the solubility of the composition of the present invention after addition of an excess amount of acid, water (23.1 grams) was placed in a vessel sitting in an ice water bath. Powdered zinc oxide (10.8 grams) was added to the water in the mixing vessel and mixed, with cooling, until dispersion. Anhydrous ammonia (9.6 grams) was metered into the zinc oxide solution slowly, with cooling, to produce a basic, ammoniacal ionic solution of zinc oxide. Thereafter, 56.5 grams of 99.9% acetic acid was slowly added with mixing, with the mixture cooled so as to maintain a temperature below 120° F. throughout mixing. After mixing was complete, the resulting solution was cooled to below 100° F. The final product had a pH of approximately 6.7, a specific gravity of 1.18 gm/ml at 25° C. and a viscosity of less than 50 centipoise at 70° F. The solution remained liquid after storage at 32° F. for 48 hours and after storage at 0° F. for 48 hours. One gram of the solution was miscible in 99 gm of a 10-34-0 solution, in 99 gm of a 9-18-9 solution and in 99 gm of a 28-0-0 solution.
EXAMPLE V
In order to test the solubility of the composition of the present invention after addition of a lesser amount of acid in a more dilute micronutrient solution sitting in an ice water bath, water (38.1 grams) was placed in a mixing vessel. Powdered zinc oxide (10.8 grams) was added to the water in the mixing vessel and mixed, with cooling, until an even dispersion was obtained. Anhydrous ammonia (9.6 grams) was metered into the zinc oxide dispersion slowly to produce a basic, ammoniacal ionic dispersion of zinc. Thereafter, 41.5 grams of 99.9% acetic acid was slowly added with mixing, with the mixture cooled so as to maintain a temperature below 120° F. throughout mixing. After mixing was complete, the resulting solution was cooled to below 100° F. The final product had a pH of approximately 7.6, a specific gravity of 1.18 gm/ml at 25° C. and a viscosity of less than 50 centipoise at 70° F. The solution remained liquid after storage at 32° F. for 48 hours and after storage at 0° F. for 48 hours. One gram of the solution was miscible in 99 gm of a 10-34-0 solution, in 99 gm of a 9-18-9 solution and in 99 gm of a 28-0-0 solution.
EXAMPLE VI
In order to test the solubility of the composition of the present invention after addition of a even lesser amount of acid in a more dilute micronutrient solution, water (47.1 grams) was placed in a container in an ice water bath. Powdered zinc oxide (10.8 grams) was added to the water in the mixing vessel and mixed, with cooling, until the zinc oxide was dispersed. Anhydrous ammonia (9.6 grams) was metered into the zinc oxide solution slowly to produce a basic, ammoniacal ionic dispersion of zinc oxide, as the jacket of the vessel was simultaneous cooled. Thereafter, 32.5 grams of 99.9% acetic acid was slowly added with mixing, with the mixture cooled so as to maintain a temperature below 120° F. throughout mixing. After mixing was complete, the resulting solution was cooled to below 100° F. The final product had a pH of approximately 8.6, a specific gravity of 1.164 gm/ml at 25° C. and a viscosity of less than 50 centipoise at 70° F. The solution remained liquid after storage at 32° F. for 48 hours and after storage at 0° F. for 48 hours. One gram of the solution was miscible in 99 gm of a 10-34-0 solution, in 99 gm of a 9-18-9 solution and in 99 gm of a 28-0-0 solution.
EXAMPLE VII
Water (47.6 grams) was placed in a mixing vessel in an ice water bath. Powdered zinc oxide (10.8 grams) was added to the water in the mixing vessel and mixed, with cooling, until a dispersion was obtained. Anhydrous ammonia (9.6 grams) was metered into the zinc oxide solution slowly to produce a basic, ammoniacal ionic dispersion of zinc oxide. Thereafter, 32.5 grams of 99.9% lactic acid was slowly added with mixing, with the mixture cooled so as to maintain a temperature below 120° F. throughout mixing. After mixing was complete, the resulting solution was cooled to below 100° F. The final product had a pH of approximately 8.6, a specific gravity of 1.164 gm/ml at 25° C. and a viscosity of less than 50 centipoise at 70° F. The solution remained liquid after storage at 32° F. for 48 hours and after storage at 0° F. for 48 hours. One gram of the solution was miscible in 99 gm of a 10-34-0 solution, in 99 gm of a 9-18-9 solution and in 99 gm of a 28-0-0 solution.
EXAMPLE VIII
Water (39.6 grams) was placed in a mixing vessel in an ice water bath. Powdered zinc oxide (10.8 grams) was added to the water in the mixing vessel and mixed, with cooling, until dispersion. Anhydrous ammonia (9.6 grams) was metered into the zinc oxide dispersion slowly to produce a basic, ammoniacal ionic solution of zinc oxide. Thereafter, 40 grams of 99.9% formic acid was slowly added with mixing, with the mixture cooled so as to maintain a temperature below 120° F. throughout mixing. After mixing was complete, the resulting solution was cooled to below 100° F. The final product had a pH of approximately 4.8, a specific gravity of 1.269 gm/ml at 25° C. and a viscosity of less than 50 centipoise at 70° F. The solution remained liquid after storage at 32° F. for 48 hours and after storage at 0° F. for 48 hours. One gram of the solution was miscible in 99 gm of a 10-34-0 solution, in 99 gm of a 9-18-9 solution and in 99 gm of a 28-0-0 solution.
EXAMPLE IX
Water (39.9 grams) was placed in a vessel in an ice water bath. Powdered manganese oxide (10 grams) was added to the water in the mixing vessel and mixed, with cooling, until dispersion of the manganese oxide was complete. Ammonium hydroxide (22 grams of 28%) was added to the manganese oxide dispersion slowly with cooling to produce a basic, ammoniacal ionic solution of manganese oxide. Thereafter, 28 grams of 99% acetic acid was slowly added with mixing, with the mixture cooled so as to maintain a temperature below 120° F. throughout mixing. After mixing was complete, the resulting solution was cooled to below 100° F. The final product had a pH of approximately 8.3, a specific gravity of 1.187 gm/ml at 25° C., a viscosity of less than 50 centipoise at 70° F., and was a rust colored opaque liquid at room temperature. The solution remained liquid after storage at 32° F. for 48 hours and after storage at 0° F. for 48 hours. One gram of the solution was miscible in 99 gm of a 10-34-0 solution, in 99 gm of a 9-18-9 solution and in 99 gm of a 28-0-0 solution.
EXAMPLE X
Water (4.8 grams) was placed in a mixing vessel together with 10 grams of 28% ammonium hydroxide. Powdered zinc oxide (10.8 grams) was added to the water in the mixing vessel and mixed, with cooling, until a complete dispersion was achieved. Additional ammonium hydroxide (23.9 grams of 28%) was added to the zinc oxide dispersion slowly to produce a basic, ammoniacal ionic dispersion of zinc oxide. Thereafter, 50.5 grams of 99% acetic acid was slowly added with mixing, with the mixture cooled so as to maintain a temperature below 120° F. throughout mixing. After mixing was complete, the resulting solution was cooled to below 100° F. The final product had a pH of approximately 5.8, a specific gravity of 1.209 gm/ml at 25° C., a viscosity of less than 50 centipoise at 70° F., and was a rust colored opaque liquid at room temperature. The solution remained liquid after storage at 32° F. for 48 hours and after storage at 0° F. for 48 hours. One gram of the solution was miscible in 99 gm of a 10-34-0 solution, in 99 gm of a 9-18-9 solution and in 99 gm of a 28-0-0 solution.
EXAMPLE XI
Water (63.1 grams) was placed in a mixing vessel sitting in an ice water bath. Powdered calcium oxide (7.4 grams) was added to the water in the mixing vessel and mixed, with cooling, until a dispersion was formed. Additional ammonium hydroxide (23.9 grams of 28%) was added to the calcium oxide dispersion slowly to produce a basic, ammoniacal ionic dispersion of calcium oxide, with cooling Thereafter, 50.5 grams of 99% acetic acid was slowly added with mixing, with the mixture cooled so as to maintain a temperature below 120° F. throughout mixing. After mixing was complete, the resulting solution was cooled to below 100° F. The final product had a pH of approximately 10.2, a specific gravity of 1.121 gm/ml at 25° C., a viscosity of less than 50 centipoise at 70° F., and was a rust colored opaque liquid at room temperature. The solution remained liquid after storage at 32° F. for 48 hours and after storage at 0° F. for 48 hours. One gram of the solution was miscible in 99 gm of a 10-34-0 solution, in 99 gm of a 9-18-9 solution and in 99 gm of a 28-0-0 solution.
EXAMPLE XII
One pint of ACA® Concentrate 15-0-0 from Platte Chemical Company of Greeley, Colo. was mixed with 1.25 pint of an aqueous solution of 50% by weight citric acid and the mixture diluted with water to 20 gallons. The resulting solution had a pH of 7.47, was initially clear after mixing and remained clear at 1 hour after mixing, two hours after mixing and 24 hours after mixing. A control test was conducted in which one pint of ACA® Concentrate 15-0-0 was diluted with water to 20 gallons. The control had a pH of 8.83 and was initially cloudy after mixing. A precipitate had formed by one hour after mixing, and the precipitate remained present at two and 24 hours after mixing.
EXAMPLE XIII
One pint of ACA 15-0-0 Concentrate was mixed with 1 pint of 100% propionic acid. The resulting micronutrient solution was clear and remained clear when diluted with water to produce a 10% solution, a 5% solution and a 1% solution. The solution remained clear when diluted 1:320 in water.
EXAMPLE XIV
Two hundred grams of ACA 15-0-0 Concentrate was mixed with 120 grams of glacial acetic acid, and eighty grams of water then added thereto. The resulting micronutrient solution was clear and remained clear when diluted with water to produce a 10% solution, a 5% solution and a 1% solution. The solution remained clear when diluted 1:320 in water.
EXAMPLE XV
Four hundred fifty one grams of water was mixed with 88 grams potassium nitrate until dissolved. One hundred sixty two grams acetic acid was added slowly to the potassium nitrate solution. Three hundred grams of ACA 15-0-0 Concentrate was added to the acidified solution to form a substantially neutral solution. Nine hundred forty grams of a 28% nitrogen solution was added to the substantially neutral solution. Thereafter 1.95 grams of sodium borate (20.5% by weight boron) available from U.S. Borax Company under its Solubor tradename, 0.03 grams of sodium molybdate (39% molybdenum) available from Cyprus-Amax Company, 15 grams of a granular citric acid copper chelate (20% copper) available from Platte Chemical Company under its Citriplex tradename, 15 grams of a granular citric acid iron chelate (20% iron) available from Platte Chemical Company under its Citriplex tradename, 15 grams of a granular citric acid manganese chelate (20% manganese) available from Platte Chemical Company under its Citriplex tradename, and 12 grams of a granular citric acid zinc chelate (25% zinc) available from Platte Chemical Company under its Citriplex tradename, were dissolved in the nitrogen solution, and filtered through a sock filter to form an enhanced micronutrient solution. This solution had a pH of 6.44, a specific gravity of 1.25 and was clear and remained clear after storage at 32° through 96 hours after mixing. The solution was also clear when diluted with water to produce a 1% solution.
To determine whether a composition of the present invention was effective in stimulating root growth in plants, five studies were conducted in which various vegetative parameters were measured after treatment of separate sets of field corn with (1) 2/3 pint per acre of a zinc ammoniacal ionic acetate solution of pH of approximately 11 having a concentration of 15% by weight ammoniacal nitrogen and 17% by weight zinc ("ACA treatment"); (2) 11/3 pint per acre of the neutralized zinc ammoniacal ionic acetate solution of Example I above (referred to herein as the ACA Neutral treatment); (3) 2 quarts per acre of the Example XV solution (referred to herein as the ACA Neutral with Chelated Metals treatment; and (4) no additional treatment (referred to in Table I as the Control). In one study, the solutions were applied as a side dressing in sandy loam, having a low overall moisture content, two inches to the side of furrow in which the corn seeds were planted. In two of the studies the solutions were applied in furrow in sandy loam having a low overall moisture content. In a fourth study the solutions were applied in-furrow to loam having a high overall moisture content, and in a fifth study, the solutions were applied in-furrow to loam having a medium overall moisture content. The results of the five studies are summarized in Table I (all lengths are in millimeters, all weights in grams).
TABLE 1__________________________________________________________________________ ACA NEUTRAL WITH CHELATEDVEGETATIVE ACA ACA NEUTRAL METALSPARAMETER TREATMENT TREATMENT TREATMENT CONTROL__________________________________________________________________________Stem diameter 4.01 4.06 3.94 3.87Shoot length 300.01 296.44 297.59 281.82Shoot wet weight 1.92 1.92 1.91 1.77Shoot dry weight 0.22 0.23 0.23 0.21Radical root length 190.06 180.87 160.30 163.75Radical root wet weight 0.61 0.61 0.47 0.58Total root dry weight 0.0667 0.0733 0.0667 0.0600Number of seminal roots 2.92 3.08 3.01 3.00Total length of seminal roots 486.08 499.63 476.23 481.5Total weight of seminal roots 0.40 0.43 0.42 0.42Number of first nodal roots 3.24 3.26 3.25 3.12Total length first nodal roots 425.54 412.83 425.69 383.94Wet weight of first nodal roots 0.29 0.29 0.29 0.26__________________________________________________________________________
It is clear that the micronutrient composition of the present invention, as tested above, is effective in stimulating root growth in corn. This composition appears to be especially effective in promoting development of seminal roots in corn, development of which is believed important to improved corn yield.
To determine whether a composition of the present invention was effective in increasing crop yield when applied with a herbicide, four studies were conducted in soybean yield was measured after postemergent treatment of soybean plants. The four treatments comprised (1) broadcast application of 3 quarts per acre of LASSO® E.C., available through Monsanto Company of St. Louis, Miss., followed by broadcast application of 100 pounds per acre of 18-46-0 granular fertilizer; (2) broadcast application of a tank mixed solution comprising by the zinc ammoniacal ionic solution described above as ACA Concentrate 15-0-0 and LASSO® E.C. in a ratio, by volume, of 1:9, applied at a rate of 3 quarts per acre of LASSO® E.C. and 2/3 pint per acre of ACA Concentrate 15-0-0; (3) broadcast application of a tank mixed solution comprising by the micronutrient solution of Example XIII and LASSO® E.C. in a ratio, by volume, of 1:9, applied at a rate of 3 quarts per acre of LASSO® E.C. and 2/3 pint per acre of the Example XIV solution; and (4) broadcast application of 3 quarts per acre of LASSO® E.C., followed by broadcast application of 100 pounds per acre of 18-46-0 granular fertilizer to which 2/3 pint of ACA Concentrate 15-0-0 had been impregnated. The results of the studies are summarized in Table II
TABLE II______________________________________ YIELD- BUSHELSTREATMENT PER ACRE______________________________________1. Herbicide, then granular fertilizer 35.252. Herbicide tank-mixed with ACA 15-0-0 Concentrate, 35.85 then granular 18-46-0 fertilizer3. Herbicide tank-mixed with Example XIII solution, 37.65 then granular 18-46-0 fertilizer4. Herbicide, then granular 18-46-0 fertilizer impregnated 36.83 w/ACA 15-0-0 Concentrate______________________________________
It is clear that the micronutrient composition of the present invention applied as described above, is effective in increasing soybean yield when used in conjunction with application of a herbicide and a granular fertilizer. Moreover, the tests results appear to show a statistically significant yield improvement over the ACA Concentrate 15-0-0 solution when applied in the same manner.
Many different agricultural crops and horticultural plants, for example turf grasses, corn, wheat, soybeans, sugar beets, sunflowers, tomatoes, potatoes, beans, alfalfa, cabbage, carrot and celery can be treated with the micronutrient compositions of the present invention. Application techniques can be significantly varied, however, because of the increased solubility of the new micronutrient compositions of the present invention. More particularly, because the metal alkanoate solutions of the present invention can be readily diluted with water, they can be applied using drip irrigation and overhead spray techniques. This allows the application of the micronutrient compositions of the present invention to be optimally scheduled, and not tied to application of another fertilizer, herbicide, or other maters. In addition, however, because of the capability of the preferred micronutrient compositions of the present invention to dilute in water, and because of the miscibility of such compositions in a wide range of fertilizer solutions, groups can maximize the number of different materials which can be mixed with the micronutrient compositions of the present inventions in a single application across the field. So, for example, this means that the micronutrient compositions of the present invention might be mixed with a herbicide and a high phosphate fertilizer and applied to acreage in a single pass. This saves the grower substantial time, labor and expense--a clear benefit to the grower.
Presently preferred embodiments of the present invention and many of its improvements have been described with a degree of particularity. It should be understood that this description has been made by way of preferred examples, and that the invention is defined by the scope of the following claims. | A substantially neutral metal alkanoate solution suitable for application of the constituent micronutrient metal to agricultural crops or acreage where such crops are to be grown, is disclosed. Alkanoates having from 2 to 6 carbon atoms are preferred, with acetates most preferred. Metals selected from the group consisting of boron, calcium, copper, iron, magnesium, manganese, molybdenum, potassium, sodium and zinc are preferred, with zinc particularly preferred. The compositions of the present invention remain soluble at and below freezing temperatures for extending periods, and exhibits a high degree of miscibility in fertilizers. A method of manufacturing the compositions of the present invention is disclosed, in which a metal oxide is dispersed in water, ammonia is added to the dispersion, and acid is added to the basic dispersion to solubilize and substantially neutralize the dispersion and create an aqueous micronutrient solution. | 2 |
CROSS REFERENCE TO RELATED APPLICATIONS
The present application is a 35 U.S.C. §§371 national phase conversion of PCT/IB2008/001532, filed Mar. 7, 2008, which claims priority of U.S. Provisional Application No. 60/894,032, filed Mar. 9, 2007, the disclosure of which is incorporated by reference herein. The PCT International Application was published in the English language.
BACKGROUND OF THE DISCLOSURE
1. Field of the Disclosure
The present disclosure relates to an improved support bearing for use, for example, for supporting the wheel end of an automobile axle.
2. Background Art
A bearing for an automotive axle performs several functions. It supports both radial and axial loads, including the weight of the vehicle and the additional wheel loads due to vehicle cornering. It transmits torque from the differential to the wheel. In particular, it is desirable to keep the torque as low as possible.
DE 80 14 137, DE 67 52 038, JP 62-210102, DE 29 07 342, DE 10 45 737, and DE 96 84 32 disclose ball bearing and cylindrical or needle roller bearing arrangements of background interest. However, none of these references discloses the automotive wheel end support bearing described herein.
SUMMARY
The bearing design for an automotive axle proposed herein combines a ball bearing and a roller bearing arrayed axially and located between an axle and a tube around the axle. Several benefits may be obtained.
A rear axle provided with such a bearing may be easier and cheaper to assemble than axles with bearings in the prior art. Unlike known bearings, a clamp load is not required across the bearing. Clamp load is required, for example, when using a known single-row taper (unitized) concept.
Also, a “C” clip is usually required in the differential at the axle when a conventional cylindrical bearing is used around the axle. With the disclosed bearing, the “C” clip conventionally required in the differential is eliminated. Also, a cylindrical roller bearing may have excessive axial play, which is particularly undesirable for a wheel speed sensor. The new bearing has less axial play.
The bearing herein may have improved axial rigidity and spindle stiffness. Thus, brake judder is reduced. This may lead to better brake response and improved disk brake wear being achieved.
The bearing may have higher efficiency (less bearing torque loss) than a conventional unitized taper. There is no sliding friction between the rolling elements and the side face.
The disclosed bearing may have the potential to reduce overall system cost. For example, an oil seal can be integrated into the bearing. It is possible to “seal the bearing for life” and move the oil seals to the ends of the differential, thus saving gear oil. The number of components in the system may be reduced as well.
According to various embodiments, an automobile wheel bearing may comprise the following components. There is an axle shaft connected to a wheel hub. An axle tube encircles a part of the shaft and is radially spaced out from the shaft. Inner and outer bearing races are formed respectively outside the axle and inside the tube and are opposed to each other. A set of rollers in a circumferential row toward the hub and a set of balls in another circumferential row further from the axle hub are disposed between and contact the inner and outer bearing races to form a ball bearing and a roller bearing, in parallel planes, for supporting the axle shaft within the axle tube.
The inner and outer raceways on the surfaces of the races may be conventionally configured for two-, three-, or four-point or angular contact with the balls of the ball bearing.
One or more seals and/or a cover plate may be positioned axially for enclosing the inner and outer bearing races and particularly for enclosing the ball and roller bearings.
The inner race of at least the roller bearing, or of both the roller bearing and the ball bearing, may be provided by portions of the axle shaft.
Other features and advantages will become apparent from the following description which refers to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial cross-sectional view showing a first embodiment of the disclosed bearing.
FIG. 2 is a partial cross-sectional view showing a second embodiment of the disclosed bearing.
FIG. 3 is a partial cross-sectional view showing a third embodiment of the disclosed bearing.
FIG. 4 is a partial cross-sectional view showing a fourth embodiment of the disclosed bearing.
FIG. 5 shows a fifth embodiment, including an arrangement for mounting the bearing on an axle.
FIG. 6 shows four possible raceway configurations for the ball bearing portion of the disclosed bearing.
DETAILED DESCRIPTION OF EMBODIMENTS
All of the disclosed embodiments of the wheel end support bearing comprise a common core of components, and redundant descriptions of the various common components will be omitted.
Referring to the embodiments in all of FIGS. 1-5 , an automobile wheel hub 10 is typically formed integrally with or attached to an axle shaft 12 . The axle shaft 12 is surrounded concentrically by an axle tube 14 spaced outward radially from the shaft. That tube may be at or part of the vehicle body or other part that does not move with the axle. A distal end 24 of the axle tube 14 is disposed substantially adjacent to but spaced away from the wheel hub 10 . The distal end 24 is considered to be “distal” in the sense of being distal from the automobile differential, which is not shown, but which would be located away from the hub 10 past the right-hand side of each of the respective Figures. This mutual arrangement of the wheel hub 10 , axle shaft 12 and axle tube 14 is well known to the art.
Also seen in FIGS. 1-5 are embodiments of a wheel bearing providing mutual or relative rotation of the axle shaft 12 and the axle tube 14 . For this purpose, there are provided a circumferential row of rollers 16 and a corresponding roller cage 18 for the roller row and a short axial distance away, a circumferential row of balls 20 and a corresponding ball cage 22 for the row of balls. The rows 16 and 20 extend circumferentially in the radial space between the axle shaft and the axle tube. Together with respective bearing races, described below, the rollers 16 form a roller bearing and the balls 20 form a ball bearing which are disposed close together axially inside the distal end 24 of the axle tube.
Embodiment 1
In the first embodiment FIG. 1 , an inner bearing race 30 comprises a cylindrical bearing ring mounted concentrically and securely around the periphery of the axle shaft 12 adjacent or substantially adjacent to the wheel hub 10 . The inner race is secured at a distal end by a shoulder 32 formed between the wheel hub 10 and the axle shaft 12 and is secured at a proximal end by a snap ring 34 which engages the shaft 12 , for example in a groove provided for that purpose.
The outer race 36 on the other hand comprises a cylindrical ring secured at a proximal end to the interior of the axle tube 14 by a shoulder 38 formed in the axle tube 14 and at a distal end by a snap ring 40 which engages the axle tube 14 , for example in a groove therein. The inner and outer races are opposed.
Appropriately indented or grooved raceways 31 and 37 are formed respectively in the inner and outer races for accommodating the row of balls 20 . The bearing rollers 16 are cylindrical and engage the raceways. No indentation is provided for the cylinders in the raceways.
No sealing elements are integrated into the bearing in this embodiment. The bearing may be lubricated by differential oil. Suitable seal elements external to the bearing may be provided.
Embodiment 2
In the second embodiment in FIG. 2 , sealing elements 50 and 52 are positioned into the bearing between the distal and proximal ends, respectively, of the inner race 30 and the outer race 36 and axially outward of the rows of rollers and balls. By these sealing elements, the bearing between the sealing elements can be one that is “sealed for life” with no additional need for outside lubrication.
An annular cover plate 54 is fastened near the radially outward edge of the plate by a plurality of bolts 56 which in turn are secured to one or more flanges 58 extending radially outwardly from the axle tube 14 . At its radially inward end, the cover plate 54 secures the distal end 60 of the outer bearing race 36 . Moreover, the cover plate 54 extends radially inward as close as is practicable to the distal end of the inner race 30 , i.e., to the shoulder 32 and to the wheel hub 10 , in order to block the entry of contaminants into the bearing.
Embodiment 3
In the third embodiment in FIG. 3 , an extended shoulder 70 formed in the axle shaft 12 extends in the proximal direction from the wheel hub 10 far enough to serve as the inner race of the more distal row of roller bearings. The same shoulder 70 also secures the distal end of the inner race 72 which accommodates the balls 20 of the ball bearing.
In this example, one oil seal 50 is integrated into one end of the bearing. The bearing may be lubricated by gear oil from the differential.
Embodiment 4
In the fourth embodiment in FIG. 4 , an extended shoulder 76 formed in the axle shaft 12 extends far enough in the proximal direction to serve as the inner race for both the ball bearing and the roller bearing. Otherwise, this embodiment may be identical to or may have the same elements as the third embodiment.
Embodiment 5
FIG. 5 shows the fifth embodiment, which is similar to FIG. 2 , but has additional features configured for mounting the bearing on an axle. In this example, the wheel hub 10 a is not integral with the axle shaft 12 as in the other embodiments. Instead, the wheel hub has a cylindrical portion 10 b that extends in the proximal direction (toward the right in the Figure). The axle shaft 12 a is substantially constant in diameter. It is threaded at its distal end 12 b . The end 12 b is passed through the cylindrical portion 10 b of the hub 10 a and is secured to the wheel hub 10 a by a nut 78 tightened on the thread at end 12 b.
The outer race 36 a has one or more radially extending flanges 36 b . This flange or these flanges 36 b are fastened by bolts 56 to corresponding flange or flanges 58 a extending radially from the axle tube 14 a.
A cover plate may also be provided, as in the second embodiment.
In this embodiment, the wheel hub 10 a , the axle shaft 12 a , the bearing ( 30 , 36 a and related components), and the axle tube 14 a are separable components, which may simplify both the assembly process and repairs when needed.
FIG. 6 shows ball raceway configurations which may be used with any of the foregoing embodiments. As shown, the raceways may be configured so as to provide (a) two-point, (b) three-point, (c) four-point, or (d) angular contact between the balls and the raceway.
U.S. Pat. No. 5,927,867 and DE 197 13 333 C2 disclose a snap ring (securing sleeve 6) that may be used as either or both of the snap rings 34 and 40 in the disclosed embodiments.
Although the present invention has been described in relation to particular embodiments thereof, many other variations and modifications and other uses will become apparent to those skilled in the art. It is preferred, therefore, that the present invention be limited not by the specific disclosure herein, but only by the appended claims. | A wheel bearing useful for automobiles includes an axle shaft and an axle tube around the shaft, inner and outer bearing races defined respectively at the outer periphery of the shaft and the inner periphery of the tube. A circumferential row of balls and a circumferential set of rollers disposed axially apart between the inner and outer bearing races to form a ball bearing and a roller bearing, in parallel, for supporting the axle shaft within the axle tube. | 5 |
FIELD OF THE INVENTION
[0001] The present invention relates to two-way actuators. Specifically, the present invention relates to two-way thermal actuators comprising a shape memory alloy, such as nitinol.
BACKGROUND OF THE INVENTION
[0002] Shape memory alloys (SMA) are alloys that exhibit the ability to return to a specific shape when brought to a certain temperature. Materials that exhibit shape memory thus have the ability to “remember” and return to a specified shape.
[0003] Nitinol, a class of nickel-titanium alloys, is well known for its shape memory properties. As a shape memory material, nitinol is able to undergo a reversible thermoelastic transformation between certain metallurgical phases. Generally, the thermoelastic shape memory effect allows the alloy to be shaped into a first configuration while in the relative high-temperature austenite phase, cooled below a transition temperature or temperature range at which the austenite transforms to the relative low-temperature martensite phase, and deformed while in the martensitic state into a second configuration. When heated, the material returns to austenite such that the alloy transforms in shape from the second configuration to the first configuration. The thermoelastic effect is often expressed in terms of the following transition temperatures: M s , the temperature at which austenite begins to transform to martensite upon cooling; M f , the temperature at which the transformation from austenite to martensite is complete; A s , the temperature at which martensite begins to transform to austenite upon heating; and A f , the temperature at which the transformation from martensite to austenite is complete.
[0004] Two-way actuation using SMAs is currently achieved in one of two ways. As an example of the first way, a single shape memory alloy is coupled to an elastic bias spring, as shown in FIGS. 1A and 1B . In FIG. 1A , at a lower temperature, which is equal to or less than M f , the nitinol spring 10 is compressed by the elastic spring 20 . As the temperature is raised to a temperature equal to or greater than A s , the nitinol spring 10 starts to expand. In FIG. 11B , at a higher temperature, which is equal to or greater than A f , the nitinol spring 10 takes on the shape as illustrated, compressing the elastic spring 20 . If the temperature is then lowered to a temperature equal to or less than M s , the nitinol spring 10 starts to compress. When the temperature lowers so that it is again equal to or less than M f , the nitinol spring 10 is again fully compressed by the elastic spring 20 , as shown in FIG. 1A .
[0005] In both FIGS. 1A and 1B , the combined spring assembly needs to be constrained by a rigid constraint 50 . Rigid constraint 50 has two ends for affixing to opposite ends of the spring assembly as well as a side support to prevent lateral movement of the spring assembly that would otherwise occur due to compression of the spring assembly between the two end constraints. One problem with this arrangement is the size of the assembly, which due to the necessity of constraining the two springs, may only be scaled down to a limited degree.
[0006] The second way of achieving two-way actuation is to laboriously train a SMA material. However, this training may require on average as many as twenty (20) heating, cooling, and constraint cycles. Therefore, since the processing is difficult and has yet to be fully perfected, limited commercial application has been-found for this type of two-way actuation.
[0007] SMA materials and specifically nitinol have been applied to numerous applications. For example, nitinol has been used for applications such as fasteners, couplings, heat engines, and various dental and medical devices. Owing to the unique mechanical properties of nitinol and its biocompatibility, the number of uses for this material in the medical field has increased dramatically in recent years and would increase further if an easier way of forming a two-way actuated SMA can be found.
SUMMARY OF THE INVENTION
[0008] If a better way to form a two-way actuated SMA can be found, the possible uses are infinite. For example, any application that requires an actuated device may use a two-way actuated SMA. The present invention provides a two-way actuated composite material, which may be used in numerous actuator systems. In one embodiment of the present invention, a two-way actuated composite material is provided. The composite material comprises a first component comprising a first shape memory alloy, and a second component, which may be selected from the group consisting of a second shape memory alloy, stainless steel, cobalt alloy, refractory metal or alloy, precious metal, titanium alloy, nickel superalloy, and combinations thereof, where the composite material forms a first shape at a temperature equal to or above A f of the first component and the composite material forms a second shape at a temperature equal to or below M f of the first component. The first component and second component may be fabricated together to form a metallurgical bond between them by working and/or heating. The second component is elastically deformable, and, during use of the actuator, the second component is elastically deformed between the second shape and the first shape. The two-way actuator may be constructed so that the elastic limit of the second component is not exceeded in the first shape, so that the spring properties cause the two-way actuator to return to the second shape upon cooling to the proper temperature.
[0009] In another embodiment of the present invention, a method is provided for using the two-way actuated composite material described above, comprising cooling the composite material below M f of the first component, heating the composite material above A f of the first component, and cooling the composite material below M f of the first component.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIGS. 1A and 1 show a prior art method of two-way actuation using nitinol.
[0011] FIGS. 2A and 2B show an embodiment of a composite material of the present invention at both a low temperature and a high temperature.
[0012] FIGS. 3A and 3B show embodiments of wires formed from composite materials in accordance with the present invention.
[0013] FIGS. 4A to 4 C show embodiments of tubes formed from composite materials in accordance with the present invention.
[0014] FIG. 5 shows an embodiment of a strip with a rectangular cross-section, the strip being formed from composite material in accordance with the present invention.
[0015] FIGS. 6A and 6B show an embodiment of the material of the present invention formed into a spring.
[0016] FIGS. 7A and 713 show another embodiment of the material of the present invention formed into a spring.
[0017] FIGS. 8A and 8B show another embodiment of the material of the present invention formed into a spring.
[0018] FIGS. 9A and 9B show an embodiment of a wire formed from material of the present invention at a low temperature and a high temperature.
[0019] FIGS. 10A and 101B show a structure usable as a delivery device formed from material of the present invention.
[0020] FIGS. 11A and 11B show a structure usable as a gripping device formed from material of the present invention.
DETAILED DESCRIPTION
[0021] The present invention provides a composite material that has two-way thermal actuation in the absence of an external bias. As one example, the composite material of the present invention may be used to reduce the profile of invasive medical device systems and improve the performance of these systems.
[0022] FIGS. 2A and 2B show an embodiment of a composite material according to the present invention. In FIG. 2A , a first component 26 , which may be an SMA, is layered on a second component 25 , which may be an elastic metal. This layering is not intended to be limiting, but may be reversed or include multiple layers.
[0023] In a, preferred embodiment, component 26 may be nitinol, and component 25 may be selected from biocompatible metals; stainless steels, such as 316 ; Co based alloys, such as MP35N or ELGILOY®; refractory metals, such as Ta, and refractory metal alloys; precious metals, such as Pt or Pd; titanium alloys, such as high elasticity beta Ti, such as FLEXFUM®; nickel superalloys; and combinations thereof. Specific stainless steel may also include austenitic or martensitic stainless steels, precipitation hardenable steels including 17-4PH, 15-4PH and 13-8Mo, or similar materials. Specific refractory metals and alloys may include Ta, Ta-10W, W, W—Re, Nb, Nb1Zr, C-103, Cb-752, FS-85, and T-111. Titanium alloys might be commercially pure, Ti6Al4V, Ti5Al2.5Sn, Beta C, Beta III or similar. In other preferred embodiments, component 26 is nitinol, and component 25 may be selected from high strength 300 Series stainless steel with an elastic recovery of approximately 1%, Beta C or Beta III titanium with an elastic recovery of approximately 1.5%, bulk metallic glass with an elastic recovery of approximately 2%, or High Elasticity Beta Ti; such as FLEXIUM™ with an elastic recovery of approximately 3-4%. The larger the elastic recovery of component 26 , the better.
[0024] Two additional examples of shape memory alloy compositions include Ti—Pt—Ni with approximately 30% Pt and Ti—Pd—Ni with approximately 50% Pd. The Ti—Pt—Ni with approximately 30% Pt has an A f of approximately 702° C. and an M f of approximately 537° C., while the Ti—Pd—Ni with approximately 50% Pd has an A f of approximately 591° C. and an M f of approximately 550° C.
[0025] The components 25 and 26 may be joined together to form the layered material by a suitable process, including working and/or heating. Suitable metal working practices known in the art include drawing, swaging, rolling, forging, extrusion, pressing, and explosive bonding. In one example of a joining method, one component may be deposited or otherwise placed on or adjacent to the other component, the two components may be fused, for example with a hot isostatic press, and the two components may be rolled to a final thickness. A metallurgical bond is formed between the components, thereby forming the layered composite. A description of composite metal fabrication processing may be found in the ASM Handbook , Volume 2, Tenth Edition, pages 1043-1059.
[0026] To set the actuator shapes for the two way actuator shown in FIGS. 2A and 2B , the layered composite is formed into a first configuration ( FIG. 2B ) thereby storing elastic energy in component 25 , the composite is held in the first configuration and heated so that the shape memory component 26 is in the relatively high-temperature austenite phase, and the composite is shaped into that first configuration as shown in FIG. 2B . The composite is then cooled below a transition temperature at which the shape memory component transforms to the relatively low-temperature martensite phase, and the stored elastic energy in component 25 forces the composite into a second configuration, as shown in FIG. 2A .
[0027] The layered composite shown in FIG. 2A is at a temperature T that is below M f of component 26 . FIG. 2B shows a bent shape achievable by heating the composite material to or above A f of component 26 . When heated to or above A f , the SMA wants to change to its remembered shape, so the composite material takes the shape shown in FIG. 2B . To return the composite to its resting state or its initial shape as shown in FIG. 2A , the temperature of the composite is lowered. The elastic properties of the composite material cause the return to this shape.
[0028] FIGS. 3A to 5 show additional embodiments of various composite material structures. FIG. 3A shows component 26 as a core of a wire with component 25 as cladding around the core. FIG. 3B shows the reverse structure, with component 25 as the core and component 26 as the cladding. These composite structures may be formed, for example, by placing a rod or tube within a tube and then drawing down to the illustrated diameter. It will be appreciated that through working and/or heat, a metallurgical bond may be formed between the two components, i.e., the core and the cladding, to form a composite structure.
[0029] FIGS. 4A to 4 C show examples of different ways of forming the composite material of the present invention into a tube. As shown in FIG. 4A , the tube may be predominantly one component, such as component 25 with an embedded ring of component 26 . As shown in FIG. 4B , the tube may comprise an outer tube of component 25 and an inner tube of component 26 . Alternatively, as shown in FIG. 4C , the tube may comprise discontinuous sections or strips of either component 25 or 26 .
[0030] The structures of FIGS. 4A and 4B may be constructed, for example, by placing tubes within other tubes and drawing. The structure of FIG. 4C may be constructed, for example, by depositing stripes of component 26 on the outer surface of a tube of component 25 , and then placing that structure inside a larger tube of component 25 , and drawing. It will be appreciated that the material of the inner and outer tubes of component 25 may fuse between the areas of the stripes of material 26 . Alternatively, the structures of FIGS. 4A-4C may be constructed by making a composite flat sheet as described above (depositing stripes in the case of FIG. 4C ), and then rolling and joining to form a tube. It will be appreciated that with these techniques involving working and/or heating, a metallurgical bond is formed between components 25 and 26 .
[0031] FIG. 5 shows another embodiment of the composite material, including a strip having a rectangular cross-section, where component 26 acts as a core and component 25 acts as cladding around the core. As will be appreciated, such a structure may be formed using techniques similar to those described above. Similar to FIG. 5 , the composite material may also be in the form of a sheet.
[0032] Further methods for forming composite structures are disclosed in U.S. patent application Ser. No. 09/702,226, the disclosure of which is hereby incorporated herein by reference.
[0033] As one skilled in the art no doubt would understand, there are any number of possible configurations and structures that may be constructed to form the composite material of the present invention, including reversing the location and structure of the components shown.
[0034] To illustrate the composite material's two-way actuation, FIGS. 6A to 8 B show embodiments of the present invention formed into various types of springs. To form the springs shown, an embodiment of the composite material of the present invention is formed into a wire and then heat treated. For example, a composite structure as shown in FIGS. 3A and 3B may be used. To form the spring, a wire is wound around a mandrel to form a coil or bias spring, and then heat treated at a suitable temperature for a suitable period of time, for example, heated to between approximately 350° C. to 650° C. for approximately 2 to 30 minutes (or longer), to set the spring shape. As an example, the heat treating range is approximately between 450° C. and 550° for between 5 and 15 minutes.
[0035] In FIGS. 6A and 6B , a spring 30 formed from the composite material of the present invention is affixed to a structure 35 . This embodiment of the present invention illustrates one possible direction of movement for an actuator. In FIGS. 6A and 6B , the spring 30 may move laterally in a single direction by expanding and contracting. For example, the spring 30 contracts or relaxes when cooled to or below the M f of component 26 , and it expands when the spring 30 is heated to or above A f of component 26 . One use for this configuration may be to reduce the size of a two way thermal actuator.
[0036] In FIGS. 7A and 7B , a spring 30 formed from a composite material of the present invention is illustrated moving laterally in two directions. In FIGS. 7A and 7B , no external fixation is used, and the spring 30 again expands and contracts based on the temperature applied. Uses for this embodiment may be to engage and release pins in a delivery system or to act as a spring trigger.
[0037] In FIGS. 8A and 8B , a tight spring 30 is formed, which expands to a larger diameter formation as temperature is applied. This configuration may be used to provide access to an area when the bias spring is enlarged and to block access to the same area by shrinking the bias spring.
[0038] FIGS. 9A-11B show examples of different geometries the composite material of the present invention may take. For example, FIGS. 9 A-B show a wire 90 formed from an embodiment of the composite material of the present invention. At T 1 (equal to or less than M f ) the wire 90 is straight; however at T 2 (equal to or more than A f ), the wire 90 bends. A use for the wire shown in FIGS. 9A and 9B may be as a shapeable guidewire or catheter.
[0039] In FIG. 10A , a tubular structure 100 formed from an embodiment of the composite material of the present invention has a seam running from one end. The tube 100 is shown in FIG. 10A at T 1 (equal to or less than M f ). At T 2 (equal to or more than A f ), as shown in FIG. 10B , the portion of the tube 100 of FIG. 10A that had the seam has opened into two separate portions 100 A and 100 B. One use for this structure may be as a delivery system, where the structure shown in FIG. 10B is used to release an item.
[0040] Similar to FIGS. 10A and 10B , FIGS. 11A and 11B show a structure that may be used as a reversible grasper or ablation grasper. In FIG. 11A , a tubular structure 120 having finger portions 130 A and 130 B is shown at T 1 (equal to or less than M f ). In FIG. 11B , the structure changes to an open configuration at T 2 (equal to or more than A f ). Alternatively, the reverse motion, i.e., moving from an open position as shown in FIG. 11B at T 1 (equal to or less than M f ) to closure as shown in FIG. 11A at T 2 (equal to or more than A f ), can also be obtained through alternative positioning during shape setting. Closure at elevated temperatures could be a useful feature in certain applications.
[0041] Many additional geometries are possible with the composite materials of the present invention. For example, the composite material may be formed into a cantilever beam, a belleville washer, a thin film membrane, a linear wire or rod, a helical spring, or a tension spring.
[0042] To use the composite material of the present invention, a two-way actuation cycle is used. In a preferred embodiment of the present invention, a body temperature/ice water actuation cycle is illustrated. In this method a composite material of the present invention is formed using Nitinol with an A f of approximately 35° C. and a M f of approximately 0° C., and one of the following materials: stainless steel, a cobalt alloy, tantalum, platinum, palladium or high elasticity titanium (FLEXIUM®). The composite material is then formed into a wire, strip, or tube. Thermal shaping is next performed, where the composite material structure is heat treated at a suitable temperature for a suitable period of time (for example, the temperatures and times stated above) and held in a particular shape, such as the bent structure shown in FIG. 2B . When the composite material is bent, the bend strain can be within the elastic range for the non-nitinol component. Following thermal shaping, the composite material may then be cooled below M f , which will soften the nitinol and allow for elastic recovery of the non-nitinol component, and thus straighten the composite material. The composite material may then be heated above A f in order to activate the memorized configuration. To release or recover from the memorized configuration, the composite material may be cooled to below M f . M f and A f may be between −200° C. to 170° C. These heating and cooling cycles may be repeated as often as necessary.
[0043] In another preferred embodiment of the present invention, a reversible two-way actuation cycle may use an elevated temperature and body temperature as the cycling temperatures. For example, a composite material structure as described above may be formed using thermal shaping. However, in this embodiment, the nitinol A f temperature is approximately 100° C. and the M f is approximately 40° C. As described above, the temperature cycling may go from cooling the composite material to heating the composite material as many times as required.
[0044] The thermal fluctuations used in these two embodiments may be any type of thermal cycling, such as different temperature fluids, electric resistance heating, induction heating, and conduction heating, in the body or otherwise. In addition, the range of thermal fluctuations may extend beyond the functional temperature range of binary nitinol. For example, if additional alloying elements are used to increase phase transformation temperature, then the upper temperature may be as high as 700° C.
[0045] While the present invention has been described with reference to what are presently considered to be preferred embodiments thereof, it is to be understood that the present invention is not limited to the disclosed embodiments or constructions. On the contrary, the present invention is intended to cover various modifications and equivalent arrangements. In addition, while the various elements of the disclosed invention are described and/or shown in various combinations and configurations, which are exemplary, other combinations and configurations, including more, less or only a single embodiment, are also within the spirit and scope of the present invention. | A two-way actuated shape memory composite material is provided. The composite material includes a shape memory alloy and an elastic metal. The composite material takes a first shape at a lower temperature and a second shape at a higher temperature. At the higher temperature, the shape memory alloy has a “remembered” shape, causing the composite material to take the second shape. The elastic material provides the composite material with elastic properties which cause the composite material to return to the first shape when cooled to the lower temperature. | 1 |
RELATED APPLICATION
[0001] This application claims priority to U.S. Provisional Patent Application Ser. No. 60/170,831 entitled Method for Reducing Myocardial Infarct by Application of Intravascular Hypothermia, the entire disclosure of such provisional application being expressly incorporated herein by reference.
FIELD OF THE INVENTION
[0002] This invention relates generally to the field of cardiac therapy, and more particularly to the intravascular application of hypothermia to prevent or reduce myocardial infarct resulting from myocardial ischemia.
BACKGROUND OF THE INVENTION
[0003] When the normal blood supply a person's heart muscle is disrupted, the person may suffer what is commonly termed a heart attack. Heart attacks are one of the major health problems in the world. In the United States alone there are over 1.1 million heart attacks a year. Of those 1.1 million victims, about 250,000 die within 1 hour. However, those that survive the initial heart attack generally subsequently receive treatment. In fact, about 375,000 of those heart attack victims will make it to a hospital for treatment within 1 hour; about 637,000 will make it to a hospital for treatment within 4 hours. Unfortunately, when treated using current methods, heart attacks often result in serious and permanent damage to the heart muscle. In fact, it is estimated that about 66% of the MI patients do not make a complete recovery, but rather suffer permanent injury to cardiac muscle cells. An effective treatment that minimizes permanent damage to the heart as a result of the heart attack would be of great value to these patents.
[0004] In a typical heart attack, there is a blockage in an artery that provide blood to some of the cardiac muscle cells, so the cells in the affected portion of the heart (termed the area at risk) experience ischemia, or a lack of adequate blood flow. This ischemia results in an inadequate supply of oxygen for the muscles and inadequate removal of waste product of muscle activity such as CO 2 , lactic acid or other by-products of metabolism. These substances may therefore reach toxic concentrations and thus, in turn, cause serious long-term consequences such as the breakdown of the cell walls, release of toxic enzymes or the like, and ultimately result in the death of many or all of the cardiac muscle cells in the area at risk.
[0005] The ischemia, however, is not always permanent. In fact, if the heart attack does not result in the immediate death of the individual, the ischemia is generally reversed either spontaneously or with medical intervention. If the ischemia is a result of blockage of an artery by a blood clot, the clot may spontaneously dissolve in the ordinary course of time due to the body's own natural thrombolytics, and blood may again flow to the affected area. Alternatively, medical treatment may restore blood flow. Such medical treatments include administration of thrombolytic drugs, such as tPA, to dissolve blood clots in the vessels of the heart to restore blood flow, balloon angioplasty, where an interventional cardiologist steers a catheter with a balloon on the end into the clogged artery and inflates the balloon to open the artery, coronary stenting, where an interventional cardiologist steers a catheter with a stent on it into the clogged vessel and expands the stent to place what amounts to a scaffold into the vessel with the blockage to hold the vessel open, or coronary by-pass surgery where a blood vessel is harvested from elsewhere in the patient's body and is attached around a blocked coronary artery to restore blood to the ischemic tissue distal of the blockage. These treatments may be applied individually or in concert with one or more of the other treatments.
[0006] Generally if the ischemic event is for a short period of time or oxygenated blood is available to the affected tissue from another blood supply, for example from collateral arteries or even from blood within the heart cavity, some or all of the muscle cells in the area at risk may survive and ultimately recover much or all of their function. However, if the period of ischemia is long enough and severe enough, the cardiac muscle cells in the area at risk may in fact die as a result of the ischemic insult. The area of dead tissue resulting from this cell death is called an infarct and the area may be said to be infarcted.
[0007] Unlike many cells in the body, for example, skeletal muscle cells, cardiac muscle cells do not significantly regenerate. Thus an infarcted region of cardiac muscle cells will generally be a permanently non-functioning portion of the patient's heart. This will result in decreased overall heart function, which may lead to systemic vascular insufficiency, congestive heart failure, and even death. It is thus of great importance to minimize the amount of infarct that results from cardiac ischemic events.
[0008] Infarct may result from heart attacks as described above, and may also result from myocardial ischemic events as the result of other causes and may even be predicable. For example, in so-called beating heart by-pass surgery, the surgeon stops the heart for short periods of time to sew grafts onto the surface of the heart. In such a procedure, the heart is deprived of blood during the time that circulation is stopped, and unless protected, infarct can result from this ischemic event.
[0009] Another common interventional procedure, cardiac balloon angioplasty, also disrupts the blood supply to part of the heart and results in predictable ischemia. In balloon angioplasty of the heart, an interventional cardiologist inserts a balloon catheter into the vasculature of the heart with the balloon deflated. The balloon is placed at a location where the interventionalist wants to dilate the vessel, and then inflates the balloon against the walls of the vessel. When the balloon is inflated, it fills the vessel in question and blocks most if not all blood from flowing through that vessel. In this way, it creates an area of ischemia downstream from the balloon, which ischemia persists for as long as the balloon is inflated. Although attempts have been made to relieve this ischemia by means of catheters that allow perfusion from one side of the balloon to the other during inflation (so called auto-perfusion balloons), these have generally proven to be inadequate.
[0010] It is also sometimes the case that during or after angioplasty the dilated vessel is either dissected or goes into spasm. If the vessel spasms shut or is dissected, the blood supply to all the tissue vascularized by the artery in question suffers severe ischemia and potential infarct. In such cases the patient is generally taken to a surgical suite and open chest by-pass is performed. Until the by-pass is successfully completed, the area at risk remains starved of blood.
[0011] Medical practitioners have attempted to reduce the infarct resulting from the ischemic events suffered during beating heart surgery and angioplasty with drugs and through a technique known as preconditioning. Drugs, for example adenosine and RheothRx, have been tried, and although under some circumstances they may have some effect, they have ultimately proven generally inadequate for one reason or another.
[0012] In preconditioning, the cardiac muscle is subjected to short periods of ischemia, for example two or three episodes of 5 minutes of ischemia followed by reperfusion, prior to the angioplasty or other anticipated procedure that will expose the heart to a more prolonged ischemic event. This has been found to reduce the infarct size resulting from the prolonged subsequent ischemia somewhat, but is difficult to perform safely, requires a complex set-up and is an invasive procedure. Importantly, precondition must occur well in advance of the ischemic event. For all these reasons it is generally not a useful procedure, and because it necessarily must occur in advance of the anticipated ischemic event, it is unsuitable for treating ischemia due to heart attacks that have already occurred or are in process.
[0013] Under ordinary circumstances, the temperature of the body and particularly that of the blood is maintained by the body's thermoregulatory system at a very constant temperature of about 37° C. (98.6° F.) sometimes referred to as normothermia. The amount of heat generated by the body's metabolism is very precisely balanced by the amount of heat lost to the environment. The circulating blood serves to keep the entire body and particularly the heart, at normothermia. Deep hypothermia (30° C. or lower) has long been known to be neuroprotective, and believed to be cardioprotective as well. More recently, the advantage of mild hypothermia (only as low as 32° C. or even as warm as between 35° C. and normothermia) to ischemic cardiac tissue has been recognized, either before and/or during an anticipated ischemic event such as may occur in beating heart surgery or coronary angioplasty, during an ischemic event such as a heart attack in progress, or soon after an ischemic event such as a heart attack that has already occurred. No satisfactory method of achieving this mild cardiac hypothermia in the human clinical setting, however, has been available before this invention. In rabbits, ice bags or ice-filled surgical gloves have been applied directly to the heart in an open-chest procedure. This method is clearly very invasive, clumsy and lacks control over the level of hypothermia applied. Other attempts have been made using cooling blankets or externally applied ice bags or iced blankets. These methods are slow, lack adequate control over the patient temperature, are not directed to the heart muscle and therefore are not effective in the human clinical setting to adequately reduce cardiac temperature, especially in obese patients.
[0014] Another method of achieving cardiac hypothermia has been proposed, that of pericardial lavage using a two-lumen catheter, with the distal ends of both lumens (one input and one outflow) sealed inside the pericardial sack. A cold solution such as cold saline is circulated within the pericardial sack to cool the heart muscle. While this method is rapid and directed to the cardiac muscle, it is highly invasive, requires surgical access to the pericardial sack which generally requires either an open chest procedure or a thoracotomy, involves piercing the pericardial sack, and introducing superfluous fluid into the pericardial sack of a beating heart, all with the attendant risks. If used, it requires the full surgical suite and delicate and highly skilled surgical technique. The surgical invasion of the pericardial sack is generally not acceptable to practitioners.
[0015] Thus, although mild cardiac hypothermia provides protection against infarct resulting from a cardiac ischemic event, the existing methods of achieving cardiac hypothermia are inadequate and unacceptable; a better method of achieving mild hypothermia of the heart that is fast, controlled and less invasive is needed.
SUMMARY OF THE INVENTION
[0016] The present invention provides a method for inducing controlled hypothermia of the heart, using an intravascular heat exchange device in the nature of a catheter. The intravascular heat exchange device is inserted into the vasculature of a mammalian patient and is thereafter utilized to cool blood that is flowing to the patient's heart. In this manner, hypothermia of the myocardium is achieved. Myocardial hypothermic treatment in accordance with this invention may be useable to prevent or lessen myocardial infarction in patient's who are suffering from acute myocardial ischemia. Also, the myocardial hypothermic treatment in accordance with this invention may be useable to prevent, deter, minimize or treat other types of damage to the myocardium such as toxic myocardial damage that can occur during or after administration of certain cardiotoxic drugs or exposure to cardiotoxic agents. Also, the myocardial hypothermic treatment in accordance with this invention may be useable to prevent, deter, minimize or treat certain cardiac disorders such as cardiac arrhythmias and the like.
[0017] The heart is the body's pump to pump blood throughout the body. A normal heart pumps blood at a rate of 3 liters per minute per square meter and the average human is 1.7 square meters, so the average heart pumps about 5.1 liter of blood per minute for entire life of the person. Under normal conditions, the blood is maintained at a very constant temperature of 37° C., and this in turn keeps the heart (and the rest of the body) at a very constant temperature of 37° C. The heart temperature is maintained by both the temperature of the arterial blood and the venous blood, in addition to the small amount of arterial blood that is re-circulated through the coronary arterial tree to feed the heart muscle (estimated to be 4% of the total circulation) the average heart pumps about 306 liters of blood per hour, blood that is all circulated through the heart cavities. Therefore cooling the venous blood that enters the heart will effectively cool the heart by direct contact with the cardiac muscle in the cardiac cavities.
[0018] As may be seen, cooling the venous blood in the vena cava also effectively cools the arterial blood that is circulated through the cardiac arteries. After being cooled in the vena cava, the blood first enters the right atrium, is then pumped through the lungs (which expose the blood to air at room temperature which is generally less than normothermia), from whence it is returned to the left atrium, and then to the left ventricle. The left ventricle pumps the oxygenated blood to the body through the aorta, and the first arteries to branch off the aorta are the coronary arteries. Thus the blood will be circulated through the arterial tree of the heart without ever having picked up metabolic heat from the rest of the body. The heart is thus cooled both by direct contact with the cooled blood and by having the cooled blood circulated through the coronary arteries before picking up metabolic heat from the outlying capillary beds.
[0019] Described herein is a method for reducing the size of any infarct that results from a cardiac ischemic event by inserting a cooling catheter having a heat exchange region into the vasculature of a patient, placing the heat exchange region into the blood stream flowing to the heart, cooling the blood as it passes the heat exchange region and thus directing cooled blood to the heart muscle before, during and/or after an ischemic event for a sufficient length of time to reduce the temperature of the heart. The method advantageously is practiced by placing the heat exchange region of the catheter into the patient's vena cava, either the inferior vena cava (IVC) or the superior vena cava (SVC), and the heat exchange region may even be placed partially or totally within the heart itself. The cooling catheter may be introduced into the patient in any acceptable means, for example percutaneously through the femoral vein into the IVC or via the internal jugular vein into the SVC, by surgical cut-down, or by surgical placement in a patient with an open chest.
[0020] The cooling of the cardiac muscle is advantageous if performed after a cardiac ischemic event, for example a heart attack, and is advantageous if performed before an anticipated ischemic event, for example before or during coronary angioplasty or beating heart surgery, and if performed during an ischemic event, for example during a heart attack in progress or during an angioplasty or beating heart surgery.
[0021] The cooling of the blood may be done by a cooling catheter having various acceptable types of cooling regions, for example a cooling catheter with a balloon for receiving the circulation of heat transfer fluid that is cooled outside of the body of the patient. Of particular value is the efficiency of a multi-lobed heat exchange balloon. Other heat exchange elements, however, are also useful in this method. For example, flexible metallic heat exchange regions or heat exchange regions with multiple heat exchange elements would be acceptable for practicing the patented method.
[0022] While the heart may experience some harmful effects of when subjected to very deep hypothermia such as arrhythmia's at temperatures below 30° C., profound reduction of infarct resulting from ischemia may be experienced as a result of mild hypothermia of only a few degrees below normothermia, for example hypothermia as mild as 35° C. or above, thereby enjoying the benefits of hypothermia while avoiding the harmful effects of deep hypothermia. Therefore cooling the heart to mild levels of hypothermia above 32° C. is preferred in this method. These temperature targets, of course, will vary somewhat from patient to patient, and from circumstance to circumstance.
[0023] Beside the level of hypothermia, the time during which the hypothermia is administered may vary according to the circumstances. For example, the heart may be cooled for a short period of time and then rewarmed, or may be cooled and maintained in a cooled condition for some period of time. For example, a heart attack victim may have the cardiac muscle cooled for an hour, while the hypothermia may be applied during beating heart surgery for several hours.
[0024] The heart may also be selectively cooled. That is, the blood directed to the heart may be cooled immediately before being directed to the heart, for example, when the blood is in the IVC, and the blood directed to the rest of the body after leaving the heart may be warmed, for example by a warming catheter in the descending aorta or warming blankets on the skin of the patient. The method of this invention tends to result in a core body temperature that is several degrees warmer than the cardiac temperature achieved, at least initially, and this difference can be accentuated and prolonged by the use of warming blankets or other means to warm the blood of the patient after the cooled blood has left the heart of the patient.
[0025] These and other objects and advantages of the invention can be better understood with reference to the drawings and the detailed description of the embodiments of the invention described below.
BRIEF DISCRIPTION OF THE DRAWINGS
[0026] FIG. 1 is a depiction of a heat exchange catheter in the vasculature of a patient with the heat exchange region of the catheter located in the vena cava of the patient.
[0027] FIG. 2 is a cross-sectional view of the shaft of a heat exchange catheter.
[0028] FIG. 3 shows a side view of the heat exchange region of a heat exchange catheter as assembled.
[0029] FIG. 4 shows the shaft member of the heat exchange catheter of FIG. 3 .
[0030] FIG. 5 shows the balloon configuration of the catheter assembly of FIG. 3 .
[0031] FIG. 6 is a view of a portion of the heat exchange catheter of FIG. 3 illustrating outflow of heat exchange fluid.
[0032] FIG. 7 is a view of a portion of the catheter of FIG. 3 illustrating inflow of exchange fluid.
[0033] FIG. 8 is a cross-sectional view of the shaft of FIG. 3 and FIG. 4 taken along the line 8 - 8 .
[0034] FIG. 9 is a cross-sectional view of the balloon of FIG. 5 taken along the line 9 - 9 .
[0035] FIG. 10 is a cross-sectional view of the catheter of FIG. 3 taken along the line 10 - 10 .
[0036] FIG. 11 is a cross-sectional view of the catheter of FIG. 3 taken along the line 11 - 11 .
[0037] FIG. 12 is a cross-sectional view of the catheter of FIG. 3 taken along the line 12 - 12 .
[0038] FIG. 13 is an illustration of a heat exchange balloon having a spiral shaped heat exchange region in place in the IVC.
[0039] FIG. 14 is an illustration of a bellows shaped heat exchange region in place in the IVC.
[0040] FIG. 15 is an illustration of a flexible metal heat transfer region with spiral shaped heat transfer fins and radial heat transfer fins on the surface of the heat exchange region, said heat exchange region in place in the IVC.
[0041] FIG. 16 is an enlarged side view of the heat transfer region of the catheter of FIG. 15 .
[0042] FIG. 17 is a cross-sectional view of the heat transfer region of FIG. 15 .
[0043] FIG. 18 . is an illustration of a heat exchange catheter having a heat exchange region comprising multiple heat exchange elements in place in the vena cava.
[0044] FIG. 19 is an illustration of a heat exchange catheter inserted into a patient via an internal jugular vein insertion, with the heat exchange region in place in the SVC.
[0045] FIG. 20 is a graph of the body temperature during cooling as measured at different locations in the body.
[0046] FIG. 21 is a flow chart depicting the steps of the method as described in the detailed description.
DETAILED DESCRIPTION
[0047] The present invention comprises a method of cooling the beating heart to protect myocardial tissue from infarct as a result of ischemia. The heart is cooled by placing a heat exchange catheter having a heat exchange region in contact with blood flowing to the heart, for example, blood in the IVC, cooling the heat exchange region to a temperature lower than that of the blood, for example circulating saline at 2° C. through the heat exchange region to cool the heat exchange region to about 2° C. thereby cooling the blood to a temperature below normothermia, and maintaining the cooling for a long enough time to reduce the temperature of the heart.
[0048] In intravenous cooling such as that described in the previous paragraph, a heat exchange region is placed in the bloodstream and maintained at a lower temperature than the blood. The rate of cooling blood by means of a heat exchange region in contact with flowing blood depends on a number of factors. One is the difference in temperature between the blood and the heat exchange region in contact with that blood. Other factors include the specific heat of the blood, the amount of surface area of the heat exchange region in contact with the blood, and the heat transfer coefficient between the blood and the surface of the heat exchange region. Certain other factors may also effect the efficiency of heat transfer between the heat exchange region and the colloidal fluid that is blood, such as turbulent flow (see e.g. U.S. Pat. No. 5,624,392 to Saab, col. 11, II. 56-60) to enhance heat exchange. Where the heat exchange region is cooled by the circulation of heat exchange fluid, counter-current flow between the blood and the heat exchange fluid is important so that the heat exchange fluid flows through the heat exchange region in a direction opposite that of the blood flow. In this way, the warm blood flows over the warmest part of the heat exchange region first toward the coldest part of the heat exchange region. It has been found that a balloon heat transfer catheter of the type described below with the heat exchange region placed in contact with blood flowing in the IVC is a satisfactory method of practicing this invention, although other heat exchange catheters with other types of heat exchange regions are within the scope of the invention.
[0049] Essentially all the blood flow into the heart cavities flows through the vena cava, the IVC below the heart and the SVC above the heart. It is estimated that in the ordinary human ⅔ of the total venous return to the heart flows through the IVC and ⅓ through the SVC. The vena cava is a large vessel; in the human patient, the IVC is generally about 200 millimeters long and generally ranges between about 160 millimeters and 260 millimeters. In diameter it varies somewhat over that length, but averages about 21 millimeters in diameter. Cooling blood flowing through the vena cava provides an effective way of inducing mild hypothermia to the heart. Blood flowing through the vena cava is flowing directly to the heart cavities. It cools the heart directly by contact with the heart muscle. The blood that feeds the cardiac arteries would also generally be relatively cool since blood cooled in the vena cava travels only to the lungs before being pumped through the cardiac arteries. In the lungs the blood is exposed to air at ambient temperature which is usually below normothermia, and the blood does not travel through the rest of the body where it would pick up metabolic heat.
[0050] Because large volumes of blood are cooled by the method of the invention, the temperature of the entire body may be somewhat depressed, that is the patient may experience what is sometimes called whole body hypothermia. Although it is generally the case the body functions most efficiently at normothermia, some whole body hypothermia is acceptable and in some situations may even by therapeutic. In any event, as the example detailed below describes, the temperature of the body core other than the cardiac muscle tends to lag the hypothermia experienced by the cardiac muscle, and this results in even shallower hypothermia than that experienced by the cardiac muscle. It is often the case that the application of cooling to the heart with the heat exchange region of the cooling catheter in the vena cava tends to be fairly short, perhaps an hour or less, so the core cooling experienced by the whole body while practicing this method is generally not harmful.
[0051] FIG. 1 shows a heat exchange catheter 10 having a heat exchange region 12 located in the IVC 14 of a patient. The heat exchange region is maintained at a temperature below that of the blood, perhaps as cold as 0° C., so that blood flowing past the heat exchange region gives off heat to the heat exchange region and thus is cooled. The cooled blood, indicated by arrows in FIG. 1 , flows into the heart 16 and cools the heart.
[0052] The balloon heat exchange catheter may be placed in the vasculature of a patient by for example, percutaneously inserting it using the well known Seldinger technique into the femoral vein 18 and advancing it toward the heart until the heat exchange region 12 is located the vena cava of the patient. In one preferred method, a balloon heat exchange catheter has a heat exchange region comprising a balloon with mechanisms for circulating cold saline through the balloon as the heat exchange fluid. The balloon is percutaneously placed into the femoral vein and advanced to locate the heat exchange balloon in the IVC. As shown in FIG. 2 , the shaft 18 of the heat exchange catheter has three lumens therein, an inflow lumen 20 for the flow of heat exchange fluid to the heat exchange region, an outflow lumen 22 for the flow of heat exchange fluid from the heat exchange region, and a working lumen 24 that may be used for a guide wire or the administration of medicaments from the proximal end of the catheter through the distal end of the catheter.
[0053] The inflow lumen is in fluid communication with the distal end of the balloon; the outflow lumen is in fluid communication with the proximal end of the balloon. The heat exchange fluid is circulated from outside the body, down the inflow lumen to the distal end of the balloon, through the balloon, and back out the outflow lumen. In this example this results in the heat exchange fluid flowing in the opposite direction of the blood, i.e. counter-current flow. This counter-current heat exchange between flowing liquids is the more efficient means of exchanging heat.
[0054] By controlling the temperature of the saline, the temperature of the balloon may be controlled. The saline may be cooled outside the body by, for instance, an external heat exchanger 26 , to cool the saline to as low as 0° C. The balloon is thereby cooled to as low as 0° C., at least at the point where the heat exchange fluid first begins to exchange heat with the blood. As will be readily appreciated, a temperature gradient is established along the length of the balloon. Where the heat exchange fluid first enters the balloon, the balloon is at its coldest. If the heat exchange fluid is at 7° C. for example, when it exits the central lumen and enters the balloon, the surface of the balloon will be essentially 0° C. At that point, if the blood is at normothermic, that is 37° C., the DT would be 30° C. and the blood would give off heat through the balloon to the heat exchange fluid. It should be noted that not all the heat exchanged between the blood and the heat exchange fluid will be at the heat exchange region. Some heat may be exchanged between the blood flowing in the femoral vein and the vena cava so the temperature at the coldest point on the heat exchange region may be as warm as 7° C. even if the saline is cooled by the external cooler to as cold as 0° C. It is preferable to exchange the maximum amount of heat in the IVC near the heart by means of the heat exchange region, but the blood in the femoral vein and IVC which may exchange heat with the shaft of the catheter ultimately flow past the heat exchange region and into the heart, so that heat exchanged by this portion of the heat exchange catheter also serves somewhat to cool the heart. Therefore, in evaluating the performance of the catheters used in the preferred embodiments of this invention, the temperature at the inlet to the heat exchange catheter, that is soon after it leaves the external heat exchanger, and the temperature at the outlet of the heat exchange catheter, that is just before it enters the external heat exchanger, in conjunction with the flow rate of heat exchange fluid in the catheter, can give a useful estimate of the heat exchanged with the blood directed to the heart, although it would include both the heat exchanged at the heat exchange region and heat exchanged along the shaft. For example, in the multi-lobed heat exchange catheter described in detail below, the temperature at the inlet may be measured at about 4° C. and the temperature at the outlet at about 11° C. The flow rate in the catheter may be about 450 ml/min. This indicated a total heat exchange of about 220 watts of energy, a performance adequate for practicing the method of this invention.
[0055] It should be noted that the exchange of heat from the body may be controlled by controlling the external heat exchanger. For example, if maximum temperature reduction were desired, maximum power to the heat exchange region would result in the coldest possible heat exchange fluid and thus the largest DT between the heat exchange fluid and the blood. Once the target temperature had been reached and the number of watts needed to be removed from the blood to maintain the target temperature was less, the watts transferred from the body could be reduced by reducing the power to the external heat exchanger. This would in turn increase the temperature of the heat exchange fluid as it left the external heat exchanger and entered the catheter, which would decrease the DT between the blood and the heat exchange fluid, and thus reduce the watts removed from the bloodstream.
[0056] The external heat exchanger may be, for example, a hot/cold plate formed of a number of thermoelectric units such as Peltier units, or other hot or cold elements in contact with a thermal exchange bag through which the heat exchange fluid is circulated. If the bag is sealed and forms a closed circuit with the heat exchange fluid in the catheter, the heat exchange fluid may be heated or cooled exterior of the body without ever being exposed to the air. If the saline is initially sterile, it may thereby be maintained sterile, an advantage for fluid that is circulated through the body. Although the heat exchange fluid is not intentionally in contact with the blood, if a leak should occur it would be a significant advantage to use sterile heat exchange fluid.
[0057] The external heat exchange unit, in turn, may controlled by controller 28 that may be pre-programmed or may be reactive to a temperature sensor 30 that senses the temperature of the patient. As will be readily appreciated by those of skill in the art, the temperature sensor may sense the temperature of the heart itself to the patient's body temperature as measured by a rectal sensor, an esophageal sensor, a tympanic sensor or the like. It has been found that the temperature sensors in the heart tissue when a heat exchange balloon is located in the vena cava tends to more closely reflect the temperature of the heat exchange balloon than do the rectal, esophageal or tympanic sensors, but that these various sensors correlate well with each other, and thus, with the appropriate compensation factors, any one of them may be used to control the temperature of the heat exchange region for purposes of inducing and controlling cardiac hypothermia.
[0058] If the external heat exchanger is able to both heat and cool, as is the case for example in the Peltier elements described above, the heat exchange fluid may be heated or cooled in response to the signal from the sensor. If the external heat exchange unit is able to be controlled as to the amount of heating or cooling it provides, the degree of heating or cooling supplied by the heat exchange unit may be controlled in response to the signal received from the sensor. As will be seen in the example described below, this will allow the operator to cool the heart to a predetermined temperature, maintain the heart at a predetermined temperature for a length of time, and add heat to the blood to warm the heart at a chosen point. In practice, the controller receives a signal that represents the temperature of the heart tissue. As this temperature nears the target temperature, the controller causes the external heat exchanger to reduce the amount of cooling applied to the heat exchanger. By internal calculations, the rate of decrease of the temperature of the heart tissue is calculated relative to the amount of energy applied by the external heat exchanger, and as the heart tissue nears and finally reaches the target temperature, the precise amount of cooling that must be applied by the external heat exchanger to cause a rate of change of essentially 0 is known. By application of this amount of cooling by the external heat exchanger when the heart reaches the target temperature, the heart is essentially maintained at precisely this temperature. In this way, by use of the controller receiving a signal from the patient's body that represents heart temperature, the operator is able to precisely control the level of hypothermia applied. By determining how long the controller will maintain this level of hypothermia and when it will begin to re-heat, the length of the hypothermia applied to the heart may also be precisely controlled.
[0059] Although the heat exchange region shown in FIG. 1 is a simple, single lobed balloon, the heat exchange region may be of various advantageous configurations. One effective catheter for exchanging heat with the blood in the vena cava is a heat exchange balloon catheter having a heat exchange region that is a multi-lobed balloon and has the temperature of the heat exchange region controlled by controlling the temperature of heat exchange fluid circulated through the balloon.
[0060] Such a catheter is depicted in FIG. 3 through FIG. 12 . The assembled catheter 31 ( FIG. 3 ) has a four-lumen, thin-walled balloon 33 ( FIG. 5 ) which is attached over an inner shaft 35 ( FIG. 4 ).
[0061] The cross-sectional view of the four-lumen balloon is shown in FIG. 9 . The balloon has three outer lumens 37 , 39 , 41 which are wound around an inner lumen 43 in a helical pattern. All four lumens are thin walled balloons and each outer lumen shares a common thin wall segment 42 with the inner lumen 43 . The balloon is approximately twenty-five centimeters long, and when installed, both the proximal end 67 and the distal end 89 are sealed around the shaft in a fluid tight seal.
[0062] The shaft 35 is attached to a hub 47 at its proximal end. The cross section of the proximal shaft is shown at FIG. 8 . The interior of the shaft is configured with three lumens, a guide wire lumen 49 , an inflow lumen 51 and an outflow lumen 53 . (For purposes of this description the inflow lumen is lumen 51 , and the outflow lumen is 53 . As one of skill in the art may readily appreciate, the inflow and outflow lumens may be reversed if desired.) At the hub, the guide wire lumen 49 communicates with a guide wire port 59 , the inflow lumen is in fluid communication with an inflow port 55 , and the outflow lumen is in communication with an outflow port 57 . Attached at the hub and surrounding the proximal shaft is a length of strain relief tubing 61 which may be, for example, heat shrink tubing.
[0063] Between the strain relief tubing and the proximal end of the balloon, the shaft 35 is extruded with an outer diameter of about 0.118 inches. The internal configuration is as shown in cross-section in FIG. 8 . Immediately proximal of the balloon attachment 67 , the shaft is necked down 63 . The outer diameter of the shaft is reduced to about 0.100 to 0.110 inches, but the internal configuration with the three lumens is maintained. Compare, for example, the shaft cross-section of FIG. 8 with the cross-section of the shaft shown in FIG. 10 and FIG. 11 . This length of reduced diameter shaft remains at approximately constant diameter of about 0.10 to 0.11 inches between the necked down location at 63 and the necked down location at 77 .
[0064] At the necked down location 63 , a proximal balloon marker band 65 is attached around the shaft. The marker band is a radiopaque material such as a platinum or gold band or radiopaque paint, and is useful for locating the proximal end of the balloon by means of fluoroscopy while the catheter is within the body of the patient.
[0065] At the marker band, all four lobes of the balloon are reduced down and fastened to the inner member 67 . This may be accomplished by folding the balloon down around the shaft, placing a sleeve, for example a short length of tubing, over the balloon and inserting adhesive, for example by wicking the adhesive, around the entire inner circumference of the sleeve. This simultaneously fastens the balloon down around the shaft and creates a fluid tight seal at the proximal end of the balloon.
[0066] Distal of this seal, under the balloon, an elongated window 73 is cut through the wall of the outflow lumen in the shaft. Along the proximal portion of the balloon, five slits, e.g. 75 , are cut into the common wall between each of the outer balloon lumens and the inner lumen 43 . (See FIG. 10 and FIG. 6 .) Because the outer lumens are twined about the inner lumen in a helical fashion, each of the outer tubes passes over the outflow lumen of the inner shaft member at a slightly different location along the length of the inner shaft, and therefore an elongated window 73 is cut into the outflow lumen of the shaft so that each outer lumen has a cut 75 where that lumen passes over the window in the shaft. Additionally, there is sufficient clearance between the outer surface of the shaft and the walls of the inner lumen 43 to create sufficient space to allow relatively unrestricted flow through the 5 slits 75 in each outer lumen 37 , 39 , 40 to the outflow lumen of the shaft 53 .
[0067] Distal of the elongated window in the outflow lumen, the inner member 43 of the four-lumen balloon is sealed around the shaft in a fluid tight seal 82 . The outflow lumen is plugged 79 , and the wall to the inflow lumen is removed. (See FIG. 11 .) This may be accomplished by necking down the shaft 77 to seal the outflow lumen shut 79 , removing the wall of the inflow lumen 81 , piercing a small hole in the wall of the inner lumen 84 and wicking UV curable adhesive into the hole and around the entire outside of the shaft, and curing the adhesive to create a plug to affix the wall of the inner lumen of the balloon around the entire outside of the shaft 83 . The adhesive will also act as a plug to prevent the portion of the inner lumen proximal of the plug from being in fluid communication with the inner member distal of the plug.
[0068] Just distal of the necked down location 77 , the guide wire lumen of the shaft may be terminated and joined to a guide wire tube 87 . The guide tube then continues to the distal end of the catheter. The inflow lumen 81 is open into the inner lumen of the four-lobed balloon and thus in fluid communication with that lumen.
[0069] The distal end of the balloon 89 including all four lumens of the balloon is sealed down around the guide wire tube in a manner similar to the manner the balloon is sealed at the proximal end around the shaft. This seals all four lumens of the balloon in a fluid tight seal. Just proximal of the seal, four slits slits 91 are cut each the common wall between each of the three outer lumens 37 , 39 , 41 of the balloon and the inner lumen 43 so that each of the outer lumens is in fluid communication with the inner lumen. (See FIG. 5 and FIG. 12 .)
[0070] Just distal of the balloon, near the distal seal, a distal marker band 93 is placed around the inner shaft. A flexible length of tube 95 may be joined onto the distal end of the guide wire tube to provide a flexible tip to the catheter. Alternatively, a soft tip 98 may be attached over the very distal end of the catheter. The distal end of the flexible tube 97 is open so that a guide wire may exit the tip, or medicine or radiographic fluid may be injected distal of the catheter through the guide wire lumen.
[0071] In use, the catheter is inserted into the body of a patient so that the balloon is within a blood vessel. Heat exchange fluid is circulated into the inflow port 55 , travels down the inflow lumen 51 and into the inner lumen 43 at the end of the inflow lumen 81 . The heat exchange fluid travels to the distal end of the inner lumen and through the slits 91 between the inner lumen 43 and the outer lumens 37 , 39 , 41 .
[0072] The heat exchange fluid then travels back through the three outer lumens of the balloon to the proximal end of the balloon. The outer lumens are wound in a helical pattern around the inner lumen. At some point along the proximal portion of the shaft, each outer lumen is located over the portion of the shaft having a window to the outflow lumen 76 , 74 , 73 , and the outer balloon lumens have slits 75 , 78 , 80 that are aligned with the windows. The heat transfer fluid passes through the slits 75 , 78 , 80 through the windows 73 , 74 , 76 and into the out flow lumen 53 . From there it is circulated out of the catheter through the outflow port 57 . At a fluid pressure of 41 pounds per square inch, flow of as much as 500 milliliters per minute may be achieved with this design.
[0073] Counter-current circulation between the blood and the heat exchange fluid is highly desirable for efficient heat exchange between the blood and the heat exchange fluid. Thus if the balloon is positioned in a vessel where the blood flow is in the direction from proximal toward the distal end of the catheter, for example if it were placed from the femoral vein into the ascending vena cava, it is desirable to have the heat exchange fluid in the outer balloon lumens flowing in the direction from the distal end toward the proximal end of the catheter. This is the arrangement described above. It is to be readily appreciated, however, that if the balloon were placed so that the blood was flowing along the catheter in the direction from distal to proximal, for example if the catheter was placed into the IVC from a jugular insertion, as is illustrated in FIG. 8 , it would be desirable to have the heat exchange fluid circulate in the outer balloon lumens from the proximal end to the distal end. Although in the construction shown this is not optimal and would result is somewhat less effective circulation, this could be accomplished by reversing which port is used for inflow direction and which for outflow.
[0074] As depicted in FIG. 13 , a catheter such as that described above, with the heat exchange region 99 located in the IVC provides an advantageous apparatus for the practice of the method of this invention. Other advantageous configurations for the heat exchange region may be employed, however. For example, the heat exchange region may have a bellows-shaped surface 100 as shown in FIG. 6 , or the heat exchange region 102 may have a surface shaped with alternating right handed spirals 104 and left handed spirals 106 with a bellows shaped surface 108 between the spirals as shown in FIGS. 14-17 . Another acceptable variation of the heat exchange catheter would have a heat exchange region 110 comprising multiple heat exchange elements 112 as illustrated in FIG. 18 .
[0075] Those of skill in the art will also readily appreciate that, beside the use of different heat exchange regions, other acceptable placements of the heat exchange region may be employed to practice the method of this invention. For example, An internal jugular insertion may be made wherein the catheter is inserted into the internal jugular vein 120 and the heat exchange region advanced to, for example, the SVC 122 as illustrated in FIG. 8 . With an internal jugular insertion, if the heat exchange region is only advanced into the SVC, the blood flow will be from the proximal to the distal end of the heat exchange region, i.e. in the same relative direction as with a femoral insertion and placement of the heat exchange region in the IVC, so counter-current flow between the heat exchange fluid and the blood will be maintained with the same catheter as described above.
EXAMPLE
[0076] The method of the invention may be described by reference to the following example. In the instance described here, the cardiac cooling method of the invention was performed using 60 B 80 kg. pigs. The study was conducted in accordance with The Guide for Care and Use of Laboratory Animals. Each pig was anesthetized with isoflourane anesthesia, and vascular sheaths were inserted percutaneoulsy in to the femoral artery and vein respectively. A median sternotomy was done, followed by the isolation of the left anterior descending coronary artery. A three lobed heat exchange catheter as described above was inserted into the sheath in the femoral vein and the catheter was advanced until the heat exchange region was in the IVC just below the heart. Saline was circulated through the heat exchange region of the catheter and an exterior heat exchanger. The exterior heat exchanger was in the form of a hot/cold plates formed by a number of Peltier units, and a bag of saline in contact with the plates. The circuit of the saline through the bag and through the catheter including the heat exchange region was closed, and the saline was sterile. The temperature of the Peltier plates, and thus of the saline, was controlled by a lap-top computer using a commercially available control program readily available to and understood by those of skill in the art, and was controlled in response to core temperature sensed by an esophageal temperature sensor of the type typically used in the medical arts.
[0077] The core temperature was initially maintained at 38° C. (normothermia for pigs) by adding or removing heat as necessary with the heat exchange catheter. Because the chest had been opened by the sternotomy, this generally comprised adding a small amount of heat to the blood. The left anterior descending coronary artery was occluded for a total of 60 minutes about ⅔ of the way down its length using a snare. The snare was formed using a suture placed around the descending coronary artery, with both legs of the suture contained within a plastic tube. The snare was tightened and the occlusion formed by sliding the tube down against the artery.
[0078] Twenty minutes into the occlusion, the external heat exchanger was turned on with the controller was set to remove heat via the heat exchange catheter to lower the cardiac temperature of the pig at the maximum rate. Heat was removed from the blood flowing through the IVC at a rate that varied somewhat between test animals from about 140 watts to 220 watts, but was generally about 190 watts.
[0079] At the end of the 60-minute period of ischemia, the snare was loosened by removing the plastic tube by sliding it away from the artery and off the suture. The removal of the snare restored flow to (re-perfused) the ischemic area. The suture was left, lose but in place around the artery. Cooling in order to maintain the target temperature of 34° C. was maintained for 15 minutes after the removal of the occlusion. In the pigs receiving hypothermia, there was thus a total of 55 minutes of cooling: beginning after 20 minutes of occlusion; 40 minutes of cooling during occlusion; then 15 more minutes of cooling after re-perfusion.
[0080] After the period of cooling (55 minutes) the external heat exchanger was switched to begin heating, and the temperature of the saline circulating through the heat exchange catheter was raised to 41° C. This in turn began warming the blood and rewarming the pig toward normothermia.
[0081] The control pigs were maintained at normothermia (38° C.) initially and during occlusion, and this temperature was maintained for an additional three hours after reperfusion. In the hypothermic pigs, re-warming toward 38° C. was allowed to occur for 2 hours and 45 minutes, that is also until three hours after reperfusion. At the end of this period (4 hours after the initial occlusion), the suture was again tied off around the artery to occlude the vessel, and monastral blue dye was injected into the left ventricular cavity to define the ischemic area at risk. The dye stained all the areas of the heart that were vascularized, and since the suture was tied off around the cardiac artery at the same location as originally occluded, the area at risk would be unstained and would visually accurately define the area at risk during the original ischemia.
[0082] The heart was harvested to analyze the effect of the hypothermia on infarct resulting from the ischemic event. The heart was excised, sliced into 0.5 to 1.0 cm slices, and the slices were immersed into 1% triphenyltetrazolium chloride (TTC) for 15 minutes to stain the viable tissue. Nonviable tissue is not stained by TTC. The myocardial slices were photographed using a digital camera and the area at risk, and the infarction zones were quantified using image analysis software. Six animals were studied with hypothermia, while an additional six animals served as controls. For the controls, the heat exchange catheter was placed into the IVC and the controller set to maintain the esophageal temperature 38° C. Otherwise, the procedure was identical for the experimental hypothermia animals and the controls. Results below are expressed as 1) Area at risk (MR), and 2) Percent of MR that suffered infarct.
[0083] Results:
HYPOTHERMIC CONTROL AAR IF/AAR AAR IF/AAR Pig # (% LV) (% AAR) Pig # (% LV) (% AAR) 1 11.3 0.0 1 25.4 49.1 2 13.6 0.0 2 12.6 35.9 3 11.2 0.0 3 14.9 44.8 4 21.1 0.8 4 33.6 45.1 5 18.2 0.0 5 17.7 61.5 6 23.7 12.8 6 10.4 47.0 Mean ± 16.6 ± 5.3 2.3 ± 5.3 Mean ± 19.1 ± 8.8 47.2 ± 8.3 SD SD P Value P = NS P < 0.000005 Hypother- mic vs. Normo- thermic
[0084] It should be noted that the core temperature of the pig as measured by the tympanic or rectal probe never reached as low a temperature as did the heart itself. A graph showing the temperatures as measured at different locations during one experiment is depicted in FIG. 20 . The cardiac temperature was measured by temperature sensors located in the muscle of the left ventricle and of the left atrium. Temperatures were also measured by sensors in the rectum, in the eardrum (tympanic) and in the esophagus. All of the temperatures measured away from the heart itself tended to lag the cardiac temperature, sometimes as much as 2° C. Presumably the fact that the heart was contacted with the cool blood first, and even warmed that blood somewhat before it went out to other locations would explain this difference.
[0085] If the heart had reached a target temperature, and the rate of cooling had been reduced to only that necessary to maintain that target temperature, the rate at which the rest of the body would have approached equilibrium would have slowed considerably, and the core body temperature as measured away from the heart would have continued to lag. Presumably, however the body would ultimately reach equilibrium at some hypothermic temperature.
[0086] This, however, would take a long time, and in the time while the heat exchange catheter was cooling the heart at hypothermic temperature, the body temperatures never reached equilibrium. Once the heat exchange catheter began to warm the blood, the entire body began to experience warming, and therefore the body core away from the heart never experienced hypothermia as deep as that experienced by the heart. For the times involved in the hypothermic treatment of the method, and for the depth of hypothermia involved, the whole body cooling that resulted was within acceptable limits.
[0087] In humans, the same method of applying hypothermia can be used to reduce infarct resulting from an ischemic event. A multi-lobed balloon catheter such as that described above, may be percutaneously placed through the femoral vein so that the heat exchange region is located in the IVC or through the internal jugular vein so that the heat exchange region is located in the SVC, and the blood therein cooled by cooling the heat exchange region (the balloon) by circulating cold saline through the cooling catheter. Saline at about 0° C. can be circulated without undue damage to the blood. A controller receiving a signal representing cardiac temperature, either directly or through some surrogate such as esophageal or tympanic temperature, can control the heat exchange catheter to achieve a target temperature and maintain that temperature. As was the case with the pigs, the heat removed from the blood also results in overall temperature reduction in the whole body since the body is unable to generate sufficient heat to replace that amount removed by the heat exchange catheter, but the heart tends to cool more rapidly than that of the rest of the body. The whole body cooling may be desirable in some instances for therapeutic reasons, for example for neuroprotection is some global ischemia is experienced, but at least at the mild levels of hypothermia in the method of the invention, and for the time lengths expected, therapeutic hypothermia of the heart is obtained by this technique without undue injury to the patient. It is anticipated that means to inhibit shivering using drugs such as meperidine, Thorazine, Demerol, phenegran or combinations thereof, or applying heat to the skin surface may be necessary to prevent or reduce shivering in unanesthesized patients receiving hypothermic therapy.
[0088] The method of the invention is described in the flow chart of FIG. 21 . In Step 1 , the heat exchange catheter is inserted into the vasculature of a patient. This is typically inserted percutaneously into the femoral vein, but may also be inserted into the internal jugular vein, or in any other suitable fashion depending on the circumstances. For example, if the patient is in surgery, insertion by a cut-down may be preferable. If access to the listed veins is not possible because the patient is aged or has other catheters or the like occupying the preferred locations, alternative locations are within the scope of the invention. Use of an insertion diameter of 8 French or less (3 F/mm) is generally preferable, but larger catheters are within the anticipated scope of the invention. Use of any of the cooling catheters described above is anticipated, as would be the use of any acceptable intravenous cooling catheter.
[0089] In step two, the catheter is advanced until the heat exchange region is in the blood stream flowing to the heart. This catheter placement is easily accomplished by those of skill in the art. It may be advanced using a guide wire, without a guide wire, using a guide catheter, or without a guiding catheter. It may be advanced using other well-known techniques as appropriate for the situation and the structure of the catheter, for example using bare wire or rapid exchange technique if applicable. It may be advanced from the femoral vein into the IVC, from an internal jugular insertion into the internal jugular vein into the SVC or the IVC, or if appropriate, even into the heart itself from either femoral or internal jugular insertion. Any location for the insertion and placement of the catheter that results in cooling of the blood directed to the heart is within the anticipated scope of this disclosure.
[0090] In step three, the heat exchange region is cooled below the temperature of the blood. The heat exchange region may be cooled to about 0° C., although it should not be cooled much below that temperature. The blood is largely water and is generally not damaged by contact with a surface that is as cold as 0° C. for the length of time that the blood is in contact with the heat exchange region, but with a surface much colder than that, blood in contact with the heat exchange region would freeze, possibly damaging the blood and decreasing the effectiveness of heat exchange. However, cooling below that temperature might be acceptable if an acceptable, safe and efficient method of cooling were employed, as long as it resulted in the cooling of the heart by means of cooling of the blood directed to the heart to reduce infarct suffered as a result of an ischemic event. The method described in greatest detail above of reducing the temperature of the heat exchange region was circulating cold saline through a balloon or hollow metallic element, or multiple heat exchange elements, to exchange heat with the blood through the surface of the heat exchange element, but other acceptable means of cooling the heat exchange region may be employed in practicing this invention.
[0091] The fourth step of the invention involves maintaining the exchanging of heat for a sufficient length of time to reduce the temperature of the heart. In the examples shown, about 240 watts of heat were being removed from the blood in the IVC to lower the temperature of the heart from 38° C. to about 33° C. in about 55 minutes. Depending on the desired level of hypothermia, the amount of blood flowing past the catheter, the number of watts of heat being removed from the blood by the heat exchange region, and similar variables, that rate of cooling may well be different and still be within the scope of this invention. It is generally the case that the cardiac temperature will be lowered to 35° C. or less to enjoy the benefits of mild hypothermia to reduce infarct, but depending on the individual situation, this may vary somewhat and still fall within the scope of this invention.
[0092] The application of hypothermia may be before the ischemic event, if an ischemic event is anticipated as is the case in surgery when it is known that the heart will be stopped for some period of time, or during balloon angioplasty when it is known that areas of the heart downstream of the balloon will be deprived of blood for some period of time. The hypothermia may be applied during the ischemia, as when it is applied during the two situations described above, whether or not it was applied before the ischemic event, or when it is applied to a heart attack victim when that victim presents. It may be applied after the ischemic event has occurred, as when it is applied to a heart attack victim soon after the ischemic event has occurred but after the ischemia has resolved and reperfusion has occurred. In all these cases and in combinations thereof, the application of mild hypothermia will generally be beneficial to prevent infarct from resulting from the ischemic event.
[0093] Step 5 involves controlling the heat exchange region in response to heart temperature. This generally involves monitoring a temperature such as rectal, tympanic, esophageal, cardiac or other temperature that may be used to determine the temperature of the heart, and controlling the heat exchange region in response to that measurement. The control of the heat exchange region may be in many forms. One form described in detail above was the control of the temperature of heat exchange fluid being circulated through a heat exchange balloon that comprised the heat exchange region. This could be done, for example, by controlling the temperature of an external heat exchanger that was in contact with a bag of saline, which saline was being circulated through the heat exchange balloon. However, if the heart temperature is determined by other factors, such as the length of time of cooling, the amount of heat transfer, or other physiological measurements, the control may be exercised based on these features.
[0094] The specific activities that may constitute control are many. Cooling may be stopped and heat added to the blood after the heart has reached a certain target temperature. Alternatively, the heat exchange region may be removed, or the heat exchange region may be returned to normothermia. In a more elegant type of control, a target temperature may be pre-selected and the amount of heat added or removed from the blood may be adjusted so that the cardiac temperature achieves the target temperature and stays at the target temperature for some pre-selected length of time, and then may warm or cool toward a second pre-selected temperature that may be normothermia, or the like. The nature of the control in response to the temperature of the heart may vary greatly and still be within the scope of this invention.
[0095] Step six, optional but sometimes a step practiced in the method, is to add heat to the hypothermic heart.
[0096] Although several illustrative examples of means for practicing the invention are described above, these examples are by no means exhaustive of all possible means for practicing the invention. The scope of the invention should therefore be determined with reference to the appended claims, along with the full range of equivalents to which those clams are entitled. | Methods and apparatus for preventing myocardial infarction, or lessening the size/severity of an evolving myocardial infarction, by cooling at least the affected area of the myocardium using an intravascular heat exchange catheter. The heat exchange catheter may be inserted into the vasculature (e.g., a vein) and advanced to a position wherein a heat exchanger on the catheter is located in or near the heart (e.g., within the vena cava near the patient's heart). Thereafter, the heat exchange catheter is used to cool the myocardium (or the entire body of the patient) to a temperature that effectively lessens the metabolic rate and/or oxygen consumption of the ischemic myocardial cells or otherwise protects the ischemic myocardium from undergoing irreversible damage or infarction. | 0 |
This application is a Continuation Application of application Ser. No. 09/723,571 filed Nov. 23, 2000, now abandoned, the entirety of which is incorporated by reference.
FIELD OF THE INVENTION
The present invention relates to drag-reducing polymer suspensions and their method of manufacture. More specifically, this invention relates to a method for preparing suspensions of ultra-high molecular weight, substantially non-crystalline, hydrocarbon-soluble polymers and wax crystal modifier polymers with decreased dissolution time in solvent hydrocarbons flowing through conduits to enhance the effect of the drag-reducing polymers.
BACKGROUND OF THE INVENTION
A drag-reducing agent is one that substantially reduces the friction loss that results from the turbulent flow of a fluid. Where fluids are transported over long distances, such as in oil and other hydrocarbon liquid pipelines, these friction losses result in inefficiencies that increase equipment and operations costs. Ultra-high molecular weight polymers are known to function well as drag-reducing agents, particularly in hydrocarbon liquids. In general, drag reduction depends in part upon the molecular weight of the polymer additive and its ability to dissolve in the hydrocarbon under turbulent flow. Effective drag-reducing polymers typically have molecular weights in excess of five million.
Drag-reducing polymers are known in the art. Representative, but non-exhaustive, samples of such art are: U.S. Pat. No. 3,692,675, which teaches a method for reducing friction loss or drag for pumpable fluids through pipelines by adding a minor amount of a ultra-high molecular weight, non-crystalline polymer; and U.S. Pat. No. 3,884,252, which teaches the use of polymer crumb as a drag-reducing material. These materials are extremely viscoelastic and, in general, have no known use other than as drag-reducing materials. However, the very properties that make these materials effective as drag-reducing additives make them difficult to handle because they have a severe tendency to cold flow and reagglomerate, even at subambient temperatures. Under conditions of pressure, such as stacking or palleting, cold flow is even more intense and reagglomeration occurs very quickly.
The general propensity of non-crosslinked elastomeric polymers (elastomers) to cold flow and agglomerate is well-known. Polymers of this sort cannot be pelletized or put into discrete form and then stored for any reasonable period of time without the materials flowing together to form large agglomerates. Because of such difficulties, elastomers are normally shipped and used as bales. However, such bales must be handled on expensive equipment and cannot be pre-blended. In addition, polymers such as the drag-reducing additives described are not susceptible to such balings, since cold flow is extremely severe. Further, dissolution time for such drag-reducing materials from a polymer state in the flowing hydrocarbons to a dissolved state is so lengthy as to severely reduce the effectiveness of this material as a drag-reducing substance.
Numerous attempts have been made to overcome the disadvantages inherent in cold-flowing polymers. Representative, but non-exhaustive, of such art is that described in U.S. Pat. No. 3,791,913, wherein elastomeric pellets are surface cured, i.e., vulcanized to a minor depth in order to maintain the unvulcanized interior of the polymer in a “sack” of cured material, and U.S. Pat. No. 4,147,677, describing a method of preparing a free-flowing, finely divided powder of neutralized sulfonated elastomer by admixing with fillers and oils. This reference does not teach a method for making free-flowing powders of non-elastomeric material. U.S. Pat. No. 3,736,288 teaches solutions of drag-reducing polymers in inert, normally liquid vehicles for addition to liquids flowing in conduits. A “staggered dissolution” effect is provided by varying the size of the polymer particles. Suspension or surface-active agents can also be used. While directed to ethylene oxide polymers, the method is useful for hydrocarbon-soluble polymers as well. U.S. Pat. No. 4,088,622 describes a method of making an improved, molded drag-reducing coating by incorporating antioxidants, lubricants, and plasticizers and wetting agents in the form of a coating which is bonded directly onto the surface of materials passing through a liquid medium. U.S. Pat. No. 4,340,076 teaches a process for dissolving ultra-high molecular weight hydrocarbon polymer and liquid hydrocarbons by chilling to cryogenic temperatures comminuting the polymer formed into discrete particles and contacting these materials at near cryogenic temperatures with the liquid hydrocarbons to more rapidly dissolve the polymer. U.S. Pat. No. 4,341,078 immobilizes toxic liquids within a container by injecting a slurry of cryogenically ground polymer particles while still at cryogenic temperatures into the toxic liquid. U.S. Pat. No. 4,420,440 teaches a method for collecting spilled hydrocarbons by dissolving sufficient polymer to form a nonflowing material of semisolid consistency by contacting said hydrocarbons with a slurry of cryogenically comminuted ground polymer particles while still at cryogenic temperatures.
Some current drag-reduction systems inject a drag-reducing polymer solution containing a high percentage of dissolved ultra-high molecular weight polymer into conduits containing the hydrocarbon. The drag-reducing polymer solution is normally extremely thick and difficult to handle at low temperatures. Depending upon the temperature of the hydrocarbon and the concentration at which the drag-reducing polymer solution is injected, significant time elapses before dissolution and resulting drag reduction. Solid polymers of these types can take days to dissolve in some cases, even though drag reduction is greatly enhanced once dissolution has finally occurred. Also, such ultra-high molecular weight polymer solutions become very viscous as polymer content increases, in some cases limiting the practical application of these solutions to those containing no more than about 15 weight percent polymer. This makes complex equipment necessary for storing, dissolving, pumping, and injecting metered quantities of drag-reducing material into flowing hydrocarbons.
Another way to introduce ultra-high molecular weight polymers into the flowing hydrocarbon stream is through a suspension. The ultra-high molecular weight polymers are suspended in a liquid that will not dissolve or will only partially dissolve the ultra-high molecular weight polymer. This suspension is then introduced into the flowing hydrocarbon stream. The tendency of the ultra-high molecular weight polymers to reagglomerate makes manufacture of these suspensions difficult. A way of controlling the tendency of the ultra-high molecular weight polymers to reagglomerate is to partially surround the polymer particles with a partitioning agent, occasionally termed a coating material, to reduce the ability of these polymers to reagglomerate. U.S. Pat. No. 4,584,244, which is hereby incorporated by reference, describes a process whereby the polymer is ground and then coated with alumina to form a free-flowing powder. Some processes using a partitioning agent require that the partitioning agent completely surround the polymer core, which requires that at least 20% and often as much as 50% of the weight of the final composition be the partitioning agent. Other examples of partitioning agents used in the art include talc, tri-calcium phosphate, calcined clay, calcium and magnesium stearate, silica, polyanhydride polymers, sterically hindered alkyl phenol antioxidants, and graphite. Partitioning agents, however, add weight to the drag-reducing agent material, resulting in higher transport costs and additional handling equipment, without any drag-reducing benefit. Further, some partitioning agents are incompatible with the hydrocarbon fluid or may be an unwanted contaminant in the hydrocarbon fluid.
SUMMARY OF THE INVENTION
Accordingly, a drag-reducing suspension and a method of producing a drag-reducing suspension are disclosed herein. One embodiment of the present invention is drawn to a drag-reducing polymer suspension composed of an ultra-high molecular weight polymer, a wax crystal modifier polymer, and a suspending fluid. In another embodiment, a method for the preparation of a drag-reducing polymer suspension is disclosed where an ultra-high molecular weight linear poly(α-olefin) is ground with a wax crystal modifier polymer at a temperature below the glass transition temperature of the ultra-high molecular weight linear poly(α-olefin) to form ground polymer particles. The ground polymer particles are then mixed with a suspending fluid to form the drag-reducing polymer suspension.
One advantage of the present invention is that the drag-reducing polymer suspension is easily transportable and does not require pressurized or special equipment for storage, transport, or injection. Another advantage is that the drag-reducing polymer is quickly dissolved in the flowing hydrocarbon stream. Yet another advantage of the present invention is that the extra bulk and cost associated with the inert partitioning agent may be reduced or eliminated, allowing easier transport. Still another advantage of the present invention is that reagglomeration of the drag-reducing polymers is greatly reduced, allowing for easier handling during manufacture. Another advantage of the present invention is that the drag-reducing polymer suspension is stable, allowing a longer shelf life and balancing of customer demand with manufacturing time. A further advantage of the present invention is that the amount of inert ingredients in the final product is reduced. Yet another advantage is that wax crystal modifier further reduces the drag of the hydrocarbon stream by lowering its pour point, reducing the viscosity of the hydrocarbon stream and thereby increasing the effectiveness of the drag-reducing agent.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic of the apparatus for manufacturing the drag-reducing polymer suspension.
DETAILED DESCRIPTION OF THE INVENTION
In the present invention, ultra-high molecular weight polymers are ground at temperatures below the glass transition temperature of the polymer or polymer blends, and then mixed in a suspending fluid. These polymers are generally not highly-crystalline. Glass transition temperatures vary with the type of polymer, and typically range between −10° C. and −100° C. (14° F. and −148° F.). This temperature can vary depending upon the glass transition point of the particular polymer or polymer blend, but normally such grinding temperatures must be below the lowest glass transition point of any polymer that comprises a polymer blend.
A preferred ultra-high molecular weight polymer is typically a linear poly(α-olefin) composed of monomers with a carbon chain length of between four and twenty carbons or mixtures of two or more such linear poly(α-olefin)s. Typical examples of these linear poly(α-olefin)s include, but are not limited to, poly(1-octene), poly(1-nonene), and poly (1-decene). The ultra-high molecular weight polymer may also be a copolymer, i.e., a polymer composed of two or more different types of monomers, as long as all monomers used have a carbon chain length of between four and twenty carbons.
As shown in FIG. 1, the ultra-high molecular weight polymer and a wax crystal modifier polymer are conveyed to coarse chopper 110 . The wax crystal modifier polymer may include one or more of the following: copolymers of olefins and acrylonitrile; copolymers of olefins, acrylonitrile, and vinyl acetate or carbon monoxide; polyalkylacrylates; copolymers of methacrylate and vinyl acetate; copolymers of olefins and vinyl acetate, such as ethylene-vinyl acetate copolymer; copolymers of olefins, vinyl acetate, and carbon monoxide, such as ethylene-vinyl acetate-carbon monoxide copolymer or propylene-vinyl acetate-carbon monoxide; and copolymers of olefins with maleic anhydride or maleic anhydride derivatives such as esters and imides such as ethylene-maleic anhydride copolymer. The wax crystal modifier polymer must be of sufficient hardness at the grinding temperature employed so as to allow grinding to less than 500 microns in diameter, typically to between 30 to 400 microns in diameter. Enough wax crystal modifier polymer should be added to coarse chopper 110 so that it forms a mixture of between 5% to 90% wax crystal modifier polymer to 10% to 95% ultra-high molecular weight polymer (all percentages in weight percent of the total mixture). These percentages may be adjusted by one of ordinary skill in the art depending on the application. The wax crystal modifier polymer may serve at least two purposes. First, it acts to partition the particles of ultra-high molecular weight polymer to prevent reagglomeration after chopping and grinding. Second, wax crystal modifier polymers may act to lower the pour point of the flowing hydrocarbon liquid. When the temperature of a hydrocarbon liquid such as crude oil, lubricating oil, or fuel oil is lowered, the waxes in these hydrocarbon liquids separate, reducing the ability of the hydrocarbon liquids to flow. A wax crystal modifier may act to modify the size and shape of the wax crystals, reducing the adhesive forces between the crystals, and between the crystals and the remainder of the hydrocarbon liquid. This reduction in adhesive forces allows the hydrocarbon liquid to remain fluid at lower temperatures and enhances the function of the drag-reducing agent by decreasing the viscosity of the flowing hydrocarbon liquid. The wax crystal modifier polymer is preferably added to coarse chopper 110 as a powder, or as small beads of 3 millimeters (⅛ inch) or less in diameter. The wax crystal modifier polymer added to coarse chopper 110 may help prevent reagglomeration of the ultra-high molecular weight polymer. Coarse chopper 110 chops large chunks of the ultra-high molecular weight polymer into small polymer pieces, typically between 1 to 1½ centimeters (⅜ inch to ⅝ inch) in diameter. While coarse chopper 110 may be operated at ambient temperatures, it is preferable to cool the polymer in coarse chopper 110 to between 5° C. to 15° C. (41° F. to 59° F.). The polymer in coarse chopper 110 may be cooled either internally or externally or both, with a liquid, gaseous, solid refrigerant or a combination thereof, but most commonly by spraying a liquid refrigerant into coarse-chopper 110 , such as liquid nitrogen, liquid helium, liquid argon, or a mixture of two or more such liquid refrigerants, or by mixing the ultra-high molecular weight polymer with dry ice (solid carbon dioxide) with or without the above-mentioned liquid refrigerants. Partitioning agent may be added in coarse chopper 110 if required to prevent reagglomeration. However, it is preferred to avoid using partitioning agent in coarse chopper 110 in order to reduce the amount of inert material in the final suspension.
The wax crystal modifier and the small pieces of the ultra-high molecular weight polymer are mixed in coarse chopper 110 to form a polymer mixture. The polymer mixture formed in coarse chopper 110 is then transported to pre-cooler 120 . This transport may be accomplished by any number of typical solids handling methods, but is most often accomplished through the use of an auger or a pneumatic transport system. Pre-cooler 120 may be an enclosed screw conveyor with nozzles for spraying a liquid refrigerant, such as liquid nitrogen, liquid helium, liquid argon, or a mixture of two or more such refrigerants onto the polymer mixture. While a gaseous refrigerant may also be used alone, the cooling efficiency is often too low. Additional wax crystal modifier polymer may be added at the inlet of pre-cooler 120 . The total amount of wax crystal modifier polymer added in both coarse chopper 110 and pre-cooler 120 may range from 10% to 95% of the total polymer mixture by weight. The wax crystal modifier polymer added at the inlet to pre-cooler 120 may be powder or small beads ranging in size of 3 millimeters (⅛ inch) or less in diameter. Pre-cooler 120 reduces the temperature of the mixture to a temperature below the glass transition temperature of the ultra-high molecular weight polymer. This temperature is preferably below 130° C. (−202° F.), and most preferably below −150° C. (−238° F.). These temperatures may be produced by any known methods, but use of liquid refrigerant such as that consisting essentially of liquid nitrogen, liquid helium, liquid argon, or a mixture of two or more such refrigerants sprayed directly on to the polymer is preferred as the resulting atmosphere reduces or eliminates hazards that exist when small polymer particles are mixed with an oxygen-containing atmosphere. The rate of addition of the liquid refrigerant may be adjusted to maintain the polymer within the preferred temperature range.
After the polymer mixture is cooled in pre-cooler 120 , it is transported to cryomill 130 . Again, this transport may be accomplished by any typical solids handling method, but often by an auger or a pneumatic transport system. A liquid refrigerant may be added to cryomill 130 in order to maintain the temperature of the polymer mixture in cryomill 130 below the glass transition temperature of the ultra-high molecular weight polymer. In one embodiment of the invention, this liquid refrigerant is added to the polymer mixture at the entrance to cryomill 130 . The temperature of the cryomill must be kept at a temperature below the glass transition temperature of the ultra-high molecular weight polymer. It is preferable to maintain the temperature of the cryomill between −130° C. to −155° C. (−202° F. to −247° F.). Cryomill 130 may be any of the types of cryomills known in the art, such as a hammer mill or an attrition mill. In an attrition cryomill, the polymer mixture is ground between a rapidly rotating disk and a stationary disk to form small particles between 10 and 800 microns in diameter. Partitioning agent may be added in cryomill 130 if required to prevent reagglomeration. However, it is preferred to avoid using partitioning agent in cryomill 130 to reduce the amount of inert material in the final suspension.
The small particles formed in cryomill 130 are then transferred to separator 140 . Most of the liquid refrigerant vaporizes in separator 140 . Separator 140 acts to separate the primarily vaporized refrigerant atmosphere from the solid polymer particles, and the larger polymer particles from the smaller polymer particles. Separator 140 may be any known type of separator suitable for separating particles of this size, including a rotating sieve, vibrating sieve, centrifugal sifter and cyclone separator. Separator 140 vents a portion of the primarily vaporized refrigerant atmosphere from cryomill 130 , and separates particles into a first fraction with less than about 400 microns in diameter from a second fraction of those with diameters of about 400 microns and above. The second fraction of those particles of about 400 microns and greater is discarded or preferably returned for recycle purposes to the pre-cooler for re-grinding. The first fraction of those particles of less than 400 microns is then transported to mix tank 150 . The 400 micron size for the particles is nominal and may vary or have a distribution anywhere from about 300 to about 500 microns depending on the type of separator, operating conditions, and the desired end use.
The small polymer particles (the first fraction) are mixed with a suspending fluid in mix tank 150 to form a suspending fluid/polymer particles mixture. The suspending fluid is any liquid that is a non-solvent for the wax crystal modifier polymer and the ultra-high molecular weight polymer. Water is most commonly used. For many other mixtures, lower carbon alcohols such as methanol, ethanol, or their mixtures with or without water, may also be used as the suspending fluid. Mix tank 150 may be any type of vessel designed to agitate the mixture to achieve uniform composition of the suspension fluid/polymer particles mixture, typically a stirred tank reactor. Mix tank 150 acts to form a suspension of the polymer particles in the suspending fluid. Other components may be added before, during, or after mixing the ground polymer particles with the suspending fluid in mix tank 150 in order to aid the formation of the suspension, and/or to maintain the suspension. For instance, gylcols, such as ethylene glycol or propylene glycol, may be added for freeze protection or as a density balancing agent. The amount of glycol added may range from 10% to 60% by weight of the suspending fluid, as needed. A suspension stabilizer may be used to aid in maintaining the suspension of the ultra-high molecular weight particles. Typical suspension stabilizers include talc, tri-calcium phosphate, magnesium stearate, silica, polyanhydride polymers, sterically hindered alkyl phenol antioxidants, and graphite. Partitioning agent added in coarse chopper 110 or cryomill 130 will often function as a suspension stabilizer as well. The total amount of partitioning agent/suspension stabilizer added may range from 0% to 40% of the suspending fluid, by weight, but is preferably between 5% and 25%, most preferably between 8% and 12%. A wetting agent, such as a surfactant, may be added to aid in the dispersal of the polymer particles to form a uniform mixture. Non-ionic surfactants such as linear secondary alcohol ethoxylates, linear alcohol ethoxylates, alkylphenol exthoxylates, and anionic surfactants, such as alkyl benzene sulfonates and alcohol ethoxylate sulfates, e.g., sodium lauryl sulfate, are preferred. The amount of wetting agent added may range from 0.01% to 1% of the suspending fluid by weight, but is preferably between 0.01% and 0.1%. In order to prevent foaming of the suspending fluid/polymer particle mixture during agitation, a suitable antifoaming agent may be used, typically a silicon oil based commercially available antifoam. Generally, no more than 1% of the suspending fluid by weight of the active antifoaming agent is used. Representative but non-exhaustive examples of antifoaming agents are the trademark of and sold by Dow Corning, Midland, Mich.; and Bubble Breaker products, trademark of and sold by Witco Chemical Company, Organics Division. Mix tank 150 may be blanketed with a non-oxidizing gas such as nitrogen, argon, neon, carbon dioxide, chlorofluorocarbons, such as those sold under the duPont trademark Freon®, hydrochlorofluorocarbons, such as those sold under the duPont trademark Suva®, or other similar gases, or the non-oxidizing gas may sparged into mix tank 150 during polymer particle addition to reduce the hazard of fire or explosion resulting from the oxidizing gas interaction with the small polymer particles possessing high surface area.
After the suspending fluid/polymer particle mixture is agitated to form a uniform mixture, a thickening agent may be added to increase the viscosity of the mixture. The increase in viscosity retards separation of the suspension. Typical thickening agents are high molecular weight, water-soluble polymers, including polysaccharides, xanthum gum, carboxymethyl cellulose, hydroxypropyl guar, and hydroxyethyl cellulose. Where water is the suspending fluid, the pH of the suspending fluid should be basic, preferably above 9 to inhibit the growth of microorganisms.
The product resulting from the agitation in the mix tank is a stable suspension of a drag-reducing polymer in a suspending fluid suitable for use as a drag-reducing agent. This suspension may then be pumped or otherwise transported to storage for later use, or used immediately.
The amounts of liquid refrigerant, wax crystal modifier polymer, suspending fluid, suspension stabilizer, partitioning agent, glycol, wetting agent, antifoaming agent, and thickener should be combined in effective amounts to accomplish the results desired and to avoid hazardous operating conditions. These amounts will vary depending on individual process conditions and can be determined by one of ordinary skill in the art. Also, where temperatures and pressures are indicated, those given are a guide to the most reasonable and best conditions presently known for those processes, but temperatures and pressures outside of those ranges can be used within the scope of this invention. The range of values expressed as between two values are intended to include the value stated in the range. | A drag-reducing polymer suspension is described, along with a method for manufacturing the drag-reducing polymer suspension. The drag-reducing suspension is easily transportable, non-hazardous, and easily handled. The drag-reducing suspension is manufactured by grinding an ultrahigh molecular weight polymer with a wax crystal modifier and suspending it in a suspending fluid. | 2 |
BACKGROUNG OF THE INVENTION
This invention relates to gas turbine engines and more particularly to engines having a shroud surrounding the tips of the rotor blades in the turbine section of the engine. In a gas turbine engine of the type referred above, pressurized air and fuel are burned in a combustion chamber to add thermal energy to the medium gases flowing therethrough. The effluent from the chamber comprises high temperature gases which are flowed downstream in an annular flow path through the turbine section of the engine. Nozzle guide vanes at the inlet to the turbine direct the medium gases onto a multiplicity of blades which extend radially outward from the engine rotor. An annular shroud which is supported by the turbine case surrounds the tips of the rotor blades to contain the medium gases flowing thereacross to the flow path. The clearance between the blade tips and the shroud is minimized to prevent the leakage of medium gases around the tips of the blades.
A limiting factor in many turbine engine designs is the maximum temperature of the medium gases which can be tolerated in the turbine without adversely limiting the durability of the individual components. The shrouds which surround the tips of the rotor blades are particularly susceptible to thermal damage. In addition, because of the close tolerances between the tips of the rotor blades and the arcuate segments comprising the shroud and the various stresses to which the engine components are subjected, the blade tips are caused to rub against the sealing surface of the shroud segment. Thus, the shroud material must be rub-tolerant so that it will not damage the blade tips and be unduly abraided by any limited contact. It is the provision of such a gas turbine engine shroud material to which this invention is directed.
BRIEF DESCRIPTION OF THE INVENTION
it has now been discovered that a sealing surface for use in a gas turbine engine shroud suitable for use in aircraft engines and the like can be made to have both excellent high temperature and rub properties. More particularly, the sealing surface of the shroud which opposes the tips of the blades is formed of an amphoteric refractory oxide matrix, a phosphate binder and optionally a stabilizer, reinforcement and/or porosity controller.
DETAILED DESCRIPTION OF THE INVENTION
Phosphate suitable for use in bonding the shroud matrix materials of the invention should be stable at the engine temperatures which are employed or stable at temperatures above about 1350° C. Exemplary of suitable phosphates are aluminum phosphate (AlPO 4 ) and zirconium pyrophosphate (Zr 2 P 2 O 7 ). Mixtures of phosphates can also be employed as well as phosphoric acid (H 3 PO 4 ) as it will form a stable phosphate during the reaction.
Amphoteric refractory oxides which can be employed as matrix materials are those which are stable at the high temperatures required and preferably have a thermal coefficient of expansion similar to that of the superalloy metal shroud block as well as a low thermal conductivity so as to require less cooling. In addition, they are preferably stable in both oxidizing and reducing environments. Exemplary of suitable materials are alumina (Al 2 O 3 ), ceria (CeO 2 ), thoria (ThO 2 ), stabilized hafnia (HfO 2 ), and stabilized zirconia (ZrO 2 ). Stabilized zirconia is preferred because its thermal coefficient of expansion is closest to high temperature airplane metals currently in use and it has a low thermal conductivity requiring less cooling than other materials. The ratio of amphoteric oxide to bonding agent can be from about 8:1 to 2:1.
Stabilizers which can be employed are those which are stable at the engine temperatures employed or stable at temperatures above about 1350° C. and which prevent a monoclinic to tetragonal transformation in zirconia or hafnia. Suitable stabilizers include yttria (Y 2 O 3 ), magnesia (MgO), and calcia (CaO) or a rare earth oxide. Typical rare earth oxides include: erbia, europia, scandia and ytterbia. Yttria is preferred particularly in combination with zirconia or hafnia. The amount of stabilizer employed will depend upon the particular stabilizer, the matrix material and other variables but generally from about 4% to 50% by weight of the matrix material is sufficient. Particulate filler to include reinforcement or porosity control material includes a variety of materials which are preferably included but not always required. For example, materials such as graphite are burned off at the high temperatures encountered in turbine engines but are useful in controlling the porosity and subsequent hardness of the bonded amphoteric refractory oxide. Other materials such as sawdust or plastic filler serve the same purpose. Reinforcing materials which do not burn out at the elevated temperatures encountered include silicon carbide fibers (whiskers) which serve to improve the fracture toughness and thermal shock resistance of the composite. Other materials which can be employed include fibrous refractory oxides such as alumina or zirconia. Reinforcing materials, such as the silicon carbide whiskers preferably have a length of between about 3-10 mm, a thickness of approximately 0.04-0.1 mm and a width of 0.1-0.5 mm.
Particle sizes of the amphoteric refractory oxide matrix materials are preferably from about submicron to 40 microns so as to provide more complete reaction although coarser particles up to 100 microns may be used as fillers. The materials can be prepared by mixing the amphoteric refractory oxide, phosphate containing material, and an amount of particulate filler material of between about 0 and about 25 weight percent sufficient to provide the desired porosity and rub properties and sufficient distilled water added to form a pourable paste which can be cast. The paste is heated for between about 4 and about 48 hours at a relatively low temperature between about 80° C. and about 120° C. until dried to set the paste and then cured at an intermediate temperature between about 120° C. and about 160° C. for between about 1 hour and about 24 hours to remove most free water and finally cured at elevated temperature between 500° C. and about 1000° C. for between about 1 hour and about 24 hours to eliminate all chemically combined water so that the cement cannot be redissolved.
Employing conventional molds and materials the resultant material can be cast and cemented in a conventional metal turbine engine shroud block to provide a sealing surface and rub tolerant shroud material.
The following examples will serve to illustrate the invention and preferred embodiments thereof. All parts and percentages in said examples and elsewhere in the specification and claims are by weight unless otherwise specified.
EXAMPLE 1
To a plastic crucible were added 20 grams -325 U.S. mesh ZrO 2 stabilized with 12% Y 2 O 3 (Zirconium Corporation of America), 5 grams of submicron particle size ZrO 2 (Zircar Products Inc.) and 3.75 grams of α-SiC whiskers. The materials were thoroughly mixed to form a nearly homogeneous dry mixture. To this mixture was added 8 grams of 85% H 3 PO 4 , and to 2 grams of distilled H 2 O to form a pourable paste which was cast into 4.91×2.45×0.58 cm mold. The paste was heated at 100° C. for 4 hours in an electric muffle furnace until the paste had set to become free standing. It was further heated at 150° C. for an additional 2 hours until dry and further cured at 600° C. for 4 hours. The material had a superficial Rockwell hardness of 93 using a 1/2" steel ball indenter and a 15 Kg load. Rub tests showed that the material had good abraidability. The material had an open porosity of about 30%.
A sample was then cut from the bar with a diamond wheel and the integrity of the sample was maintained when it was repeatedly heated to near white heat in an oxygen-methane flame and immediately plunged into cold water. Thus the material had excellent thermal shock resistance.
EXAMPLE 2
To a plastic container were added 20 grams of -325 U.S. mesh ZrO 2 stabilized with 12% Y 2 O 3 , and 3 grams of α-SiC whiskers. The material were thoroughly dry mixed and to this mixture was added 10 grams of Al(H 2 PO 4 ) 3 solution. The material was packed into a 5.32×2.53×0.63 cm mold which was heated for 12 hours at 80° C., 2 hours at 100° C., and 2 hours at 120° C. until completely set. An additional heating of 2 hours at 200° C. and 6 hours at 600° C. completed the heat treatment. The cured material had a density of 2.74 g/cm 4 and had good particulate erosion resistance.
EXAMPLES 3-5
To a plastic crucible is added 20 grams of a -325 U.S. mesh oxide or hydroxide of thorium, hafnium or cerium with 3 grams of α-SiC whiskers. The materials are thoroughly dry mixed to form a homogeneous mixture and to this mixture is added 8 grams of phosphoric acid or 10 grams of Al(H 2 PO 4 ) 3 . The materials are further mixed to form a paste or pourable mixture and are cast in the desired mold or aircraft engine shroud block. A heat treatment of 4-25 hours at a temperature of 80°-120° C. causes setting and further gradual heating to 600° C. causes final curing. The final materials have essentially the same properties as the materials described in examples 1 and 2, but the thermal expansion coefficients are similar to the expansion coefficient of the refractory oxide used.
Those skilled in the art will understand that the examples are intended to be illustrative of preferred compositions and are intended to be nonlimiting except as defined by the appended claims. | High temperature resistant turbine engine shrouds are formed of an amphoteric refractory oxide, a phosphate binding agent and optionally a stabilizer, reinforcement and/or porosity controller. | 5 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to channel estimation in a telecommunication system, and more particularly, data-aided channel estimation.
[0003] 2. Description of Related Art
[0004] It is very well known that coherent methods of channel estimation give about 3 dB of gain over non-coherent methods, provided that perfect knowledge of the channel fading parameters (amplitude and phase) is known. In practical applications, such perfect knowledge is never achieved, and a receiver must estimate the fading parameters. This estimation is prone to errors, and thus, the “promised” 3 dB gain may rapidly start to vanish as the accuracy of the channel-estimation algorithm decreases. This problem appears in communication systems where channel fading and coherent detection are present (e.g., CDMA2000, 3GPP, and ARIB—where the channel parameters are usually estimated from a pilot signal). Common losses from channel estimation errors in these systems can range from 0.1 dB up to 3 dB, depending on the specifics of the channel and the system.
[0005] Under consideration is the problem of estimating the complex-valued channel gain (also called “complex fading coefficient”) experienced by a BPSK-modulated symbol transmitted over a single path of a (possibly multipath) fading channel. A complex discrete-time received sequence is generated by demodulation (e.g., correlator or matched filter) and sampling of each path. For symbol i, the effect of fading on the received signal, y i , can be modeled as
y
i
=a
i
x
i
+v
i
[0006] where a, is the complex-valued fading coefficient, x, ∈{±1} is the transmitted data bit (which can be either +1 or −1), and v i , is the complex background additive white Gaussian noise with zero mean and per-component variance σ 2 . It is assumed that the fading is sufficiently slow so that the channel gain is approximately constant over consecutive symbols. Hence, the symbol subscript on the channel gain a is removed.
[0007] Conventional DS-CDMA channel estimation is performed through the use of a reference signal known as a pilot. The pilot may be transmitted in a number of different ways. One approach is to provide a channel, separate from the data channel, exclusively for the pilot signal. This method is used by both the European (UMTS) and the North American (CDMA 2000) third generation wireless systems. A second approach is to time-multiplex pilot symbols with data symbols. This approach is used, for example, in the Japanese third generation wireless system (ARIB). Although the above two methods have fundamental differences, the underlying concept is the same.
[0008] With pilot-aided (PA) channel estimation, the pilot data bit, χ i , is known to the receiver. Without loss of generality, we assume that χ i =1 for all pilot symbols. Therefore, for pilot symbol i, the received signal statistic y i,p is
y
i,p
=a
p
+v
i
[0009] where a p is the complex channel gain for the pilot signal, v i represents the background noise and is Gaussian, and p represents that a variable is based on pilot symbols. Typically, the transmit energy of the pilot signal is kept as small as possible in an effort to minimize the consumption of battery power and added interference. Hence, the pilot signal does not necessarily have the same energy as the data signal. Since the goal is to estimate a and not a p , the following weighting is applied to the channel gain of the pilot signal
y
i,p
=βa+v
i
[0010] where β is a known, chosen design parameter.
[0011] For each received pilot symbol, a simple individual estimated realization of the channel gain, â i,p , can be formulated as
â i,p =y i,p
[0012] Data-aided (DA) channel estimation offers an alternative approach by making use of the data symbols in addition to (or in lieu of) the pilot symbols. The difficulty with DA estimation is that the data symbols are not known a priori (as is the case with pilot symbols), which makes the estimation more challenging—and more noisy too. DA channel estimation can be implemented in conjunction with PA channel estimation by means of a stage-by-stage iterative procedure. In the first stage, a PA-only channel estimate is generated. This estimate is then used to detect the data symbols, which in turn are used as new “pseudo-pilot” information to revise the PA channel estimate. This process can be repeated, and may be implemented as a loop within the decoding stage of the receiver. Typically, the information in each data symbol is estimated, then the information is removed and a channel gain estimate is generated using an averaging window.
[0013] DA channel estimation is an efficient way to assist channel estimation because it makes use of data information that is already available at the receiver. The goal is to reduce the pilot symbol overhead and/or reduce the required transmit energy of pilot symbols. However, conventional DA channel estimate methods are computationally intensive and exhibit larger than desired variance.
SUMMARY OF THE INVENTION
[0014] In the method of the present invention, estimated individual realizations of the complex-valued fading coefficient, commonly called channel estimates, are generated. According to the inventive method, these realizations are easy to generate and can produce a channel estimate that exhibits a smaller variance in comparison to conventional methods.
[0015] A level of confidence for each possible value of a transmitted data symbol is determined based on a received data symbol corresponding to the transmitted data symbol. The confidence level associated with a particular possible value is the level of confidence that the transmitted symbol was the particular possible value. Using the confidence levels, a channel estimate is generated.
[0016] Unlike conventional data-aided channel estimate methods, the method according to the present invention does not require making an explicit calculation (called a hard decision) of an estimate of the transmitted symbol. Instead the present invention offers a soft decision alternative that does not require performing any maximizations. Consequently, the methodology of the present invention offers an easy means of determining a data-aided channel estimate that exhibits a smaller variance in comparison to conventional methods.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The present invention will become more fully understood from the detailed description given herein below and the accompanying drawings which are given by way of illustration only, wherein like reference numerals designate corresponding parts in the various drawings, and wherein:
[0018] [0018]FIG. 1 illustrates a plot of the confidence function h(y i,d ) versus the log-likelihood ratio λ; and
[0019] [0019]FIG. 2 illustrates an apparatus for making a channel estimate according to one embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] In the method of the present invention, estimated individual realizations of the complex-valued fading coefficient, commonly called channel estimates, are generated. According to the inventive method, these realizations are easy to generate and can produce a channel estimate that exhibits a smaller variance in comparison to conventional methods.
[0021] Using the received signal y i,d , the channel estimate is defined as:
â i,d =h(y i,d )y i,d . (1)
[0022] where â i,d is the channel estimate, h( ) is any predefined function that can be designed based on a specific constellation and channel being used, i represents the ith estimate, and d represents that the parameter or variable pertains to data symbols (as opposed to a pilot symbols).
[0023] For the purposes of discussion only, the method of the present invention will described for the bi-phase shift keying (BPSK) constellation and an over-the-air communication channel. In BPSK, the transmitted symbol is either +1 or −1. However, from the following disclosure, it will be understood that application of the method of the present invention is not limited to a particular constellation or channel. In a preferred embodiment for BPSK modulation, h(y i,d ) is defined as:
h ( y i,d ) =P ( x i =+1| y i,d )− P ( x i =−1| y i,d ), (2)
[0024] where P(x i =+1|y i,d ) is the a posteriori probability that a transmitted data symbol x i =+1 was transmitted conditioned on the observation of the received data symbol y i,d corresponding to the transmitted data symbol x i , and where P(x i =−1|y i,d ) is the a posteriori probability that a transmitted data symbol x i =−1 was transmitted conditioned on the observation of the received data symbol y i,d corresponding to the transmitted data symbol x i . Here, P(x i =+1|y i,d ) represents a confidence level, based on the received data symbol y i,d , that the corresponding transmitted data symbol x i had a value of +1. And, P(x i =−1|y i,d ) represents a confidence level, based on the received data symbol y i,d , that the corresponding transmitted data symbol x i had a value of −1.
[0025] Using Bayes' rule, equation (2) can be rewritten as equation (3a) below:
P ( x i = + 1 y i , d ) = p ( y i , d x i = + 1 ) P ( x i = + 1 ) p ( y i , d ) (3a)
[0026] where p(y i,d ) represents a probability density function of the received statistic evaluated at y i,d .
[0027] A similar expression exists for P(x i =−1|y i,d ).
P ( x i = - 1 y i , d ) = p ( y i , d x i = - 1 ) P ( x i = - 1 ) p ( y i , d ) (3b)
[0028] Under the assumption that P(x i =+1)=P(x i =−1)=0.5 using the Law of Total Probability, p(y i,d ) is given by equation (4) below:
p ( y i , d ) = 1 2 ( p ( y i , d x i = + 1 ) + p ( y i , d x i = - 1 ) ) (4)
[0029] The well-known log-likelihood ratio (LLR) is defined as:
λ ( y ) = λ 1 ( y ) - λ - 1 ( y ) = ln ( p ( y x = + 1 ) p ( y x = - 1 ) ) (5)
[0030] where In( ) represents the natural logarithm. It is known that y conditioned on x is a complex Gaussian random variable with mean ax and per-components variance σ 2 , (i.e., noise), where σ 2 is determined according to any well-known technique. Therefore, the LLR is given by equation (6) below:
λ ( y ) = λ 1 ( y ) - λ - 1 ( y ) = - ( ( y - a ) 2 2 σ 2 ) - ( ( y + a ) 2 2 σ 2 ) = 2 a * y σ 2 ( 6 )
[0031] Combining Equations (1)-(6) results in:
a ^ i , d = ( e λ ( y i , d ) - 1 e λ ( y i , d ) + 1 ) y i , d . ( 7 )
[0032] Returning to Equation (2), h (y i,d ) is given by:
h ( y i , d ) = e λ ( y i , d ) - 1 e λ ( y i , d ) + 1 . ( 8 )
[0033] A plot of this function with respect to λ is given in FIG. 1. The function is odd and is bounded by ±1, and bears a strong resemblance to the sign( ) function.
[0034] As will be appreciated, h(y i,d ) represents the confidence that the transmitted symbol x i is a particular value in view of the corresponding received symbol y i,d . Stated another way, h(y i,d ) indicates the strength or degree of confidence that the transmitted symbol x i is a particular value in view of the corresponding received symbol y i,d .
[0035] Next, the overall data-based estimate is found by averaging the individual realizations of the channel estimate over a weighted time window:
a ^ d = 1 2 N d + 1 ∑ j = i - N d i + N d K j , d a ^ j , d = 1 2 N d + 1 ∑ j = i - N d i + N d K j , d ( e λ ( y i , d ) - 1 e λ ( y i , d ) + 1 ) y i , d ( 9 )
[0036] where K i,d is a weighting constant, 2N d +1 is the window over which the estimate is averaged, and N d is a number of samples.
[0037] Unlike conventional data-aided channel estimate methods, the method according to the present invention does not require making an explicit calculation (called a hard decision) of an estimate of the transmitted symbol. Instead the present invention offers a soft decision alternative that does not require performing any maximizations. A simple evaluation of the LLR, a well-known receiver calculation already made in most receivers, is used. Consequently, the methodology of the present invention offers an easy means of determining a data- aided channel estimate that exhibits a smaller variance in comparison to conventional methods.
[0038] Once the appropriate pilot-aided (PA) and data-aided (DA) channel estimates and their variances are obtained, they can be combined in an optimal manner. In the present invention, optimality is defined as minimum variance in the final estimate. The PA channel estimate â (p) can be determined according to any well-known technique, and therefore will not be described. The variances σ p 2 and σ d 2 of the PA and DA channel estimates â (p) and â (d) can be determined according to any well-known statistical technique; and therefore will not be described. The final channel estimate, â is a linear combination of the PA and DA channel estimates,
a ^ = w p a ^ ( p ) + w d a ^ ( d ) , (10)
[0039] where w p and w d are non-negative constants. Assuming that E[â (p) ]=E[â (d) ]=a, where E[] represents the average value, the added constraint that
w p +w d =1 (11)
[0040] ensures that E[â]=a.
[0041] Under the assumption that the PA and DA channel estimates are independent, the variance of the overall estimate is
Var( â ) +w p 2 σ p 2 +w d 2 σ d 2 . (12)
[0042] To minimize this variance subject to the constraint in equation (11) and w p ,w d being non-negative, w d =1−w p is substituted in Equation (12). Then, equation (12) is differentiated with respect to w p , set equal to zero, and solved for w p . The result is
w p = σ d 2 σ p 2 + σ d 2 ,
and ( 13 ) w d = σ d 2 σ p 2 + σ d 2 (14)
[0043] A check of the second derivative confirms that the solution is indeed a minimum.
[0044] Accordingly, by substituting equations (13) and (14) into equation (10), the channel estimate can be calculated using the PA channel estimate, the variance of the PA channel estimate, the DA channel estimate and the variance of the DA channel estimate.
[0045] An apparatus for implementing the above-described embodiment of the present invention will now be described with reference to FIG. 2. As will be appreciated from the forgoing, the apparatus of FIG. 2 forms a part of a receiver. Because the other components of the receiver are well-known, applicants have not illustrated and will not describe these other components for the sake of brevity.
[0046] As shown in FIG. 2, a shift register 10 inputs the received symbols y i from a demodulator (not shown). As alluded to above, also not shown are the well-known components for determining the per-component noise or variance σ 2 , the pilot-aided channel estimate â p , the variance σ p 2 of the pilot-aided channel estimate and the variance σ d 2 of the data aided channel estimate. An LLR calculator 12 receives the received symbol y i from the shift register 10 and the square of the standard deviation, and calculates the LLR of the received symbol y i according to equation (6). As will be appreciated, equation (6) requires, during a first iteration, an initial channel estimate as an input variable. In a preferred embodiment, the channel estimate based on the pilot symbols is used as the initial channel estimate, and then each subsequent iteration uses the channel estimate determined based on the combined data aided and pilot-aided channel estimates as shown in FIG. 2.
[0047] Next, a confidence factor generator 14 generates a confidence factor h(y) according to equation (8) using the output of the LLR calculator 12 . A multiplier 16 multiplies the confidence factor with the received symbol y i on a per component basis to obtain an individual realization of the channel estimate based on the received data according to equation (1). A weighted time window averager 18 stores the output of the multiplier 16 and calculates a weighted average of the data-aided channel estimate according to equation (9).
[0048] A channel estimate combiner 20 receives the output of the weighted time window averager 18 and the pilot symbol based channel estimate, calculates the variances of the DA channel estimate and the PA channel estimate, and generates the channel estimate according to equations (10), (13) and (14). The channel estimate is then used in the conventional manner to determine the transmitted symbols x i , and is also feedback to the LLR calculator 12 to be used in the LLR calculation.
[0049] The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications are intended to be included within the scope of the following claims. | In the method of making a channel estimate, at least first and second confidence levels that a transmitted data symbol has respective first and second values are determined based on a received data symbol corresponding to the transmitted data symbol. A channel estimate is then determined based on the first and second confidence levels. | 7 |
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